Appendicitis (Clinical)

Overview

Definition

Appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis is the inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the vermiform appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy.

Epidemiology^[1,4,5]

• Lifetime risk: approximately 8%
• 6% of the population gets appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis.
• Peak incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 10–19 years of age
• Males > females
• The most common acute surgical problem in the pediatric population

Etiology^[1,4,18]

• Obstruction of appendiceal orifice (implicated, but not often proven)
• Cause of obstruction varies with age.
  • Children and young adults: lymphoid follicular hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation secondary to infection
  • Older adults:
    • Fecaliths
    • Calculi
    • Fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans
    • Tumors ( benign Benign Fibroadenoma or malignant)
  • Rare: parasites (usually in endemic areas)

Pathophysiology and Clinical Presentation

Pathophysiology^[1,4,18]

• Obstruction of appendiceal orifice is the 1st step (presumed).
• Mucus accumulation and luminal distention:
  • Bacterial overgrowth Bacterial overgrowth Lactose Intolerance (mixed; aerobes and anaerobes Anaerobes Lincosamides):
    • Escherichia coli Escherichia coli The gram-negative bacterium Escherichia coli is a key component of the human gut microbiota. Most strains of E. coli are avirulent, but occasionally they escape the GI tract, infecting the urinary tract and other sites. Less common strains of E. coli are able to cause disease within the GI tract, most commonly presenting as abdominal pain and diarrhea. Escherichia coli 
    • Peptostreptococcus Peptostreptococcus A genus of gram-positive, anaerobic, coccoid bacteria that is part of the normal flora of humans. Its organisms are opportunistic pathogens causing bacteremias and soft tissue infections. Perianal and Perirectal Abscess
    • Pseudomonas Pseudomonas Pseudomonas is a non-lactose-fermenting, gram-negative bacillus that produces pyocyanin, which gives it a characteristic blue-green color. Pseudomonas is found ubiquitously in the environment, as well as in moist reservoirs, such as hospital sinks and respiratory equipment. Pseudomonas
    • Bacteroides fragilis Bacteroides fragilis Gram-negative bacteria occurring in the lower intestinal tracts of man and other animals. It is the most common species of anaerobic bacteria isolated from human soft tissue infections. Bacteroides
  • Increase in transmural pressure → thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus and occlusion of small vessels
  • Ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage ( gangrene Gangrene Death and putrefaction of tissue usually due to a loss of blood supply. Small Bowel Obstruction)
  • Eventual perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis

Time course^[1,4]

Early:

• Usually first 24 hours
• Distention of the appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy stimulates T8–10 afferent Afferent Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology nerves.
• Vague periumbilical pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways develops.

Late:

• Usually after 24 hours
• Invasion of appendiceal wall by bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology + ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage
• Propagation Propagation Propagation refers to how the electrical signal spreads to every myocyte in the heart. Cardiac Physiology of neutrophilic exudate Exudate Exudates are fluids, cells, or other cellular substances that are slowly discharged from blood vessels usually from inflamed tissues. Pleural Effusion → fibropurulent reaction involving serosal surface
• Peritoneal irritation → localized pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and tenderness

Perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis:

• Affects 13%–20% of cases
• In 65% of cases, symptoms last longer than 48 hours.
• In 20% of cases, symptoms last less than 24 hours.
• More likely with calculus as the obstructing culprit:
  • Walled-off perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis: abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease formation
  • Free perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis: generalized peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury

Clinical presentation^[1,4,8,9]

Classic:

• Periumbilical pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways that later migrates to the right lower quadrant Right lower quadrant Anterior Abdominal Wall: Anatomy (RLQ)
• Anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa
• Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics/ vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
• Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever

Atypical:

• Indigestion
• Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
• Generalized malaise Malaise Tick-borne Encephalitis Virus

Anatomic factors:

• Anterior appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy (most common): pronounced localized RLQ pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Retrocecal: dull abdominal pain Abdominal Pain Acute Abdomen
• Pelvic: dysuria Dysuria Painful urination. It is often associated with infections of the lower urinary tract. Urinary Tract Infections (UTIs), diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea, tenesmus (from bladder Bladder A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination. Pyelonephritis and Perinephric Abscess and rectal irritation)

Diagnosis

History^[5–9]

• Duration of symptoms: typically 24–48 hours
• Abdominal pain Abdominal Pain Acute Abdomen:
  • Sudden onset 
  • Constant, becoming progressively worse
  • Exacerbated by movement
• Anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa, nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics, diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea/ constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation may or may not be present.
• Symptoms may be vague/atypical in the elderly.
• Adults (eliminate other causes):
  • History of inflammatory bowel disease
  • History of colorectal cancer Colorectal cancer Colorectal cancer (CRC) is the 2nd leading cause of cancer-related deaths in the United States. Colorectal cancer is a heterogeneous disease that arises from genetic and epigenetic abnormalities, with influence from environmental factors. Colorectal Cancer/previous colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening
  • Reproductive/sexually transmitted diseases in women (rule out pelvic inflammatory disease Pelvic inflammatory disease Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Gardnerella vaginalis. Pelvic Inflammatory Disease ( PID PID Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and gardnerella vaginalis. Pelvic Inflammatory Disease), ectopic pregnancy Ectopic pregnancy Ectopic pregnancy refers to the implantation of a fertilized egg (embryo) outside the uterine cavity. The main cause is disruption of the normal anatomy of the fallopian tube. Ectopic Pregnancy)
• Children:
  • Most common in 5–12-year-olds
  • Very rare in neonates
  • Rule out viral illness:
    • History of concurrent or preceding respiratory symptoms
    • History of sick contacts with similar symptoms

Physical exam^[5–9]

General:

• Low-grade fever Low-Grade Fever Erythema Infectiosum (up to 38.3°C (101°F))
• High fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever may indicate late appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis/ necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage/ perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis.
• Desire to lie still, with difficulty ambulating (common in children)
• Signs of dehydration Dehydration The condition that results from excessive loss of water from a living organism. Volume Depletion and Dehydration if prolonged vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia/ anorexia Anorexia The lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa. Anorexia Nervosa:
  • Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
  • Orthostatic hypotension Orthostatic hypotension A significant drop in blood pressure after assuming a standing position. Orthostatic hypotension is a finding, and defined as a 20-mm hg decrease in systolic pressure or a 10-mm hg decrease in diastolic pressure 3 minutes after the person has risen from supine to standing. Symptoms generally include dizziness, blurred vision, and syncope. Hypotension
  • Decreased urinary output

Abdominal exam:

• RLQ tenderness
• Localized rebound tenderness Rebound Tenderness Acute Abdomen (peritoneal irritation)
• Signs:
  • McBurney’s point McBurney’s point Appendicitis tenderness: maximal tenderness at 3.8–5.0 cm (1.5–2 in) from anterior iliac spine Anterior Iliac Spine Appendicitis on a straight line to the umbilicus 
  • Rovsing’s sign Rovsing’s sign A positive sign when there is pain in the RLQ with palpation of the left lower quadrant Appendicitis: pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in the RLQ with palpation Palpation Application of fingers with light pressure to the surface of the body to determine consistency of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs. Dermatologic Examination of the left lower quadrant Left Lower quadrant Anterior Abdominal Wall: Anatomy
  • Psoas sign Psoas sign When there is RLQ pain with passive hip extension (characteristic of retrocecal appendix) Appendicitis: RLQ pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with passive hip extension Extension Examination of the Upper Limbs (characteristic of retrocecal appendix Retrocecal appendix Appendicitis)
  • Obturator sign Obturator sign When there is RLQ pain with internal hip rotation with a flexed knee (pelvic appendix) Appendicitis: RLQ pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with internal hip rotation Rotation Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. X-rays with a flexed knee ( pelvic appendix Pelvic appendix Appendicitis)
• Generalized peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury suggests perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis.

Rectal exam:

• Not helpful for establishing appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis diagnosis
• May be helpful if an alternative diagnosis is suspected

Pelvic exam:

• May be needed in a female if PID PID Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and gardnerella vaginalis. Pelvic Inflammatory Disease is suspected
• Appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis (especially pelvic) may also produce tenderness on pelvic exam.

Laboratory studies^[2,5,6,9]

• Complete blood count (CBC): leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus with a left shift Left Shift Yersinia pestis/Plague
• Inflammatory markers: ↑ erythrocyte sedimentation rate Erythrocyte Sedimentation Rate Soft Tissue Abscess ( ESR ESR Soft Tissue Abscess), C-reactive protein (CRP)
• Chemistry may show dehydration Dehydration The condition that results from excessive loss of water from a living organism. Volume Depletion and Dehydration pattern: low K ( potassium Potassium An element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Hyperkalemia), low Na ( sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia), metabolic alkalosis Alkalosis A pathological condition that removes acid or adds base to the body fluids. Respiratory Alkalosis
• Urinalysis Urinalysis Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically. Urinary Tract Infections (UTIs) in Children: may show mild pyuria Pyuria The presence of white blood cells (leukocytes) in the urine. It is often associated with bacterial infections of the urinary tract. Pyuria without bacteriuria can be caused by tuberculosis, stones, or cancer. Urinary Tract Infections (UTIs) due to proximity of the right ureter
• Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care test: Perform on all females of reproductive age.

Alvarado score Alvarado score Appendicitis^[2,5,9]

• A numerical scale Scale Dermatologic Examination for predicting the likelihood of appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis based on clinical and laboratory findings
• Facilitates decision making
• Mnemonic: MANTRELS

Imaging^{[2,5–7,9,16]}

Imaging is not required for diagnosis if the Alvarado score Alvarado score Appendicitis is very low (< 3) or high (> 7).

• Computed tomography (CT) scan:
  • Highest diagnostic accuracy
  • Should be performed with intravenous contrast unless contraindicated ( renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome, allergy Allergy An abnormal adaptive immune response that may or may not involve antigen-specific IgE Type I Hypersensitivity Reaction)
  • Findings of appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis:
    • Appendiceal diameter > 6 mm (0.24 in) with occluded lumen
    • Appendiceal wall thickening  > 2 mm (0.08 in)
    • Appendiceal wall enhancement
    • Periappendiceal fat stranding
    • Appendicolith Appendicolith Imaging of the Intestines (in about 25% of cases)
• Ultrasound (US):
  • Lower diagnostic accuracy than CT
  • Operator dependent
  • Preferred test in children and pregnant women as it avoids radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma
  • Signs of appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis:
    • Non-compressible appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy
    • Appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy diameter > 6 cm (2.4 in)
    • Focal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with pressure from US probe Probe A device placed on the patient’s body to visualize a target Ultrasound (Sonography)
    • Increased echogenicity of surrounding fat
    • Fluid in RLQ
    • “ Target sign Target sign Pseudomembranous Colitis”:
      • Hypoechoic Hypoechoic A structure that produces a low-amplitude echo (darker grays) Ultrasound (Sonography) (fluid-filled lumen)
      • Hyperechoic Hyperechoic A structure that produces a high-amplitude echo (lighter grays and white) Ultrasound (Sonography) (mucosa/submucosa)
      • Hypoechoic Hypoechoic A structure that produces a low-amplitude echo (darker grays) Ultrasound (Sonography) (muscularis layer)
• Magnetic resonance imaging (MRI):
  • Inferior to CT scan
  • An alternative when CT is contraindicated

Management

Initial management^[7,10,16]

• Intravenous fluid resuscitation Resuscitation The restoration to life or consciousness of one apparently dead. . Neonatal Respiratory Distress Syndrome (hydrate and replace electrolytes Electrolytes Electrolytes are mineral salts that dissolve in water and dissociate into charged particles called ions, which can be either be positively (cations) or negatively (anions) charged. Electrolytes are distributed in the extracellular and intracellular compartments in different concentrations. Electrolytes are essential for various basic life-sustaining functions. Electrolytes)
• NPO (nothing by mouth)
• Analgesia Analgesia Methods of pain relief that may be used with or in place of analgesics. Anesthesiology: History and Basic Concepts
• Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics control

Uncomplicated appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis

Definition: acute appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis without clinical or radiographic signs of perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis

Non-operative management (NOM):^[5-7,10]

• Growing evidence that non-perforated appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis can be managed with antibiotics alone
• 90% will initially respond to antibiotics.
• Indications:^[10]
  • Localized appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis, without signs of diffuse peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury
  • No imaging evidence of abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease, perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis, or tumor Tumor Inflammation
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship without appendicolith Appendicolith Imaging of the Intestines on imaging studies ( appendicolith Appendicolith Imaging of the Intestines is associated with treatment failure in NOM)
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship who are unfit for surgery (multiple comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus) or who accept the risk of recurrence
• The following are generally not candidates for NOM:
  • Immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship who are hemodynamically unstable or have sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock
  • Pregnant women:^[19] 
    • Appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy is recommended owing to morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status, risk of preterm labor Preterm labor Preterm labor refers to regular uterine contractions leading to cervical change prior to 37 weeks of gestation; preterm birth refers to birth prior to 37 weeks of gestation. Preterm birth may be spontaneous due to preterm labor, preterm prelabor rupture of membranes (PPROM), or cervical insufficiency. Preterm Labor and Birth, and fetal loss.
    • NOM can serve as a bridge to surgery in remote areas or where skilled surgical staff is not available.
• Adult antibiotic regimens:^[5,8,11,16] 
  • Single-agent regimen:
    • Cefoxitin
    • Ertapenem Ertapenem A carbapenem derivative antibacterial agent that is more stable to renal dehydropeptidase I than imipenem, but does not need to be given with an enzyme inhibitor such as cilastatin. It is used in the treatment of gram-positive and gram-negative bacterial infections including intra-abdominal infections, acute gynecological infections, complicated urinary tract infections, skin infections, and respiratory tract infections. It is also used to prevent infection in colorectal surgery. Carbapenems and Aztreonam 
    • Moxifloxacin Moxifloxacin A fluoroquinolone that acts as an inhibitor of DNA topoisomerase II and is used as a broad-spectrum antibacterial agent. Fluoroquinolones 
    • Piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins– tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins (for high-severity infection)
  • Metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess PLUS 1 of the following:
    • Cefazolin Cefazolin A semisynthetic cephalosporin analog with broad-spectrum antibiotic action due to inhibition of bacterial cell wall synthesis. It attains high serum levels and is excreted quickly via the urine. Cephalosporins 
    • Cefuroxime
    • Ceftriaxone Ceftriaxone A broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears. Cephalosporins
    • Cefotaxime Cefotaxime Semisynthetic broad-spectrum cephalosporin. Cephalosporins 
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones 
    • Levofloxacin Levofloxacin The l-isomer of ofloxacin. Fluoroquinolones 
• Pediatric antibiotic regimens:^[8,14]
  • Ceftriaxone Ceftriaxone A broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears. Cephalosporins PLUS metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess
  • Piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins– tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins
  • Penicillin-allergic: ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones PLUS metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess
• Antibiotics course:
  • 7–10 days
  • 1–3 days IV, if on a nothing-by-mouth regimen or unable to tolerate oral intake
  • Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are typically able to tolerate oral doses after 48 hours. 
  • Switch to oral doses once able to tolerate
• Recurrence rate of 20%–30% in the 1st year, and up to 39% in 5 years

Appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy:^[5,6]

• Timing:
  • Delay of 12–24 hours does not increase morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status or risk for complicated appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis.
  • Delay beyond 24 hours, however, increases adverse outcomes.
• Performed in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship who are fit for surgery and do not accept the risks of possible recurrence.
• Preoperative antibiotics are indicated and should be given within 60 min of the start of the procedure.^[12]
• Adult prophylaxis Prophylaxis Cephalosporins:^[15]
  • Cefoxitin 2 g IV every 2 hours if redose needed; OR
  • Cefotetan 2 g IV every 6 hours if redose needed; OR
  • Metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess 500 mg IV plus cefazolin Cefazolin A semisynthetic cephalosporin analog with broad-spectrum antibiotic action due to inhibition of bacterial cell wall synthesis. It attains high serum levels and is excreted quickly via the urine. Cephalosporins:
    • For < 120 kg, give 2 g IV every 4 hours (if redose needed)
    • For 120 kg, give 3 g IV every 4 hours (if redose needed)
  • Penicillin- or cephalosporin-allergic: clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides 900 mg IV one dose, PLUS 1 of the following:
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones 400 mg IV, one dose
    • Levofloxacin Levofloxacin The l-isomer of ofloxacin. Fluoroquinolones 500 mg IV, one dose
    • Gentamicin Gentamicin Aminoglycosides 5 mg/kg IV, one dose 
    • Aztreonam Aztreonam The carbapenems and aztreonam are both members of the bactericidal beta-lactam family of antibiotics (similar to penicillins). They work by preventing bacteria from producing their cell wall, ultimately leading to bacterial cell death. Carbapenems and Aztreonam 2 g IV, one dose
• Pediatric prophylaxis Prophylaxis Cephalosporins:^[15]
  • Cefoxitin 40 mg/kg IV; maximum dose: 2 g every 2 hours if redose needed, OR
  • Cefotetan 40 mg/kg IV; maximum dose: 2 g every 6 hours if redose needed, OR
  • Ceftriaxone Ceftriaxone A broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears. Cephalosporins 50–75 mg/kg IV 
  • Piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins– tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins:
    • Over 9 months and ≤ 40 kg: 100 mg/kg IV; maximum dose: 3 g piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins/dose
    • > 40 kg, 3 g IV, every 2 hours if redose needed 
  • Penicillin-allergic:
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones 10 mg/kg IV; maximum: 400 mg/dose; PLUS
    • Metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess 15 mg/kg; maximum dose: 500 mg
• Approach:
  • Laparoscopic:
    • Lower rate of wound infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease
    • Less pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways on postoperative day 1
    • Shorter hospital stay
  • Open:
    • Lower rate of intra-abdominal infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease
    • Shorter operative time Operative time The duration of a surgical procedure in hours and minutes. Surgical Infections
• Postoperative antibiotics are not indicated.^[13]

Complicated appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis

Definition: appendiceal rupture with or without phlegmon or abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease formation

Initial non-operative management:^[5,7,8] 

• Preferred approach as immediate surgery has high risk of complications:
  • More extensive surgery (ileocecectomy) may be required.
  • Risk of postoperative abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease, fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula
• Indicated for contained perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis:
  • Cecal phlegmon or abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease > 3 cm (1.18 in) on CT scan
  • Stable patient without diffuse peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury
• Components of management:
  • Radiologically guided drainage of an abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease
  • IV antibiotics: broad-spectrum Broad-Spectrum Fluoroquinolones enteric coverage including Enterobacteriaceae Enterobacteriaceae A family of gram-negative, facultatively anaerobic, rod-shaped bacteria that do not form endospores. Its organisms are distributed worldwide with some being saprophytes and others being plant and animal parasites. Many species are of considerable economic importance due to their pathogenic effects on agriculture and livestock. Cephalosporins (nonresistant), streptococci, and anaerobes Anaerobes Lincosamides (See NOM section for antibiotics) 
  • IV fluids IV fluids Intravenous fluids are one of the most common interventions administered in medicine to approximate physiologic bodily fluids. Intravenous fluids are divided into 2 categories: crystalloid and colloid solutions. Intravenous fluids have a wide variety of indications, including intravascular volume expansion, electrolyte manipulation, and maintenance fluids. Intravenous Fluids and bowel rest
• Successful (patient is discharged home with 7–10-day course of oral antibiotics):
  • ↓ Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • ↓ Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • ↓ Leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus
• Unsuccessful: rescue appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy during the same admission

Interval appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy:^[5,6,17] 

• Generally performed 6–8 weeks after successful nonoperative management:
  • To prevent recurrence of appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis
  • To exclude appendiceal neoplasm
• If not performed, proponents of interval appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy cite the following risks:
  • Up to 30% risk of recurrence during the 1st year
  • 10%–29% risk of neoplasm in perforated appendix Perforated Appendix Appendectomy 
• Although there are benefits, some argue against routine interval appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy (after NOM for complicated appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis) in those who are < 40 years old and in children, citing:
  • High rate of resolution after NOM
  • High incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency of no future events in majority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
• Shared decision-making is recommended regarding the procedure.
• Colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening should also be considered for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship > 40 years of age because of the increased risk of malignancy Malignancy Hemothorax in this age group. 

Immediate appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy:^[5,18] 

• Always indicated for unstable patient with generalized peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury/free perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis 
• May require more extensive resection (ileocecectomy)
• Requires washout and drainage of peritoneal cavity Peritoneal Cavity The space enclosed by the peritoneum. It is divided into two portions, the greater sac and the lesser sac or omental bursa, which lies behind the stomach. The two sacs are connected by the foramen of winslow, or epiploic foramen. Peritoneum: Anatomy
• Can also be performed for contained perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis with small phlegmon or abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease (< 3 cm (1.18 in))
• Postoperative antibiotics are recommended:
  • Duration:
    • Adults, 3–5-day course (see NOM section for antibiotic regimens)
    • Children, < 7-day course (see NOM section for antibiotic regimens) 
  • Longer course may be needed in cases of:
    • Incomplete drainage
    • Presence of catheters
    • Surgical complications Surgical complications Surgical complications are conditions, disorders, or adverse events that occur following surgical procedures. The most common general surgical complications include bleeding, infections, injury to the surrounding organs, venous thromboembolic events, and complications from anesthesia. Surgical Complications

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas^[5,6]

• Mortality Mortality All deaths reported in a given population. Measures of Health Status is low: 0.09%–4%
• Complications of appendectomy Appendectomy Appendectomy is an invasive surgical procedure performed with the goal of resecting and extracting the vermiform appendix through either an open or a laparoscopic approach. The most common indication is acute appendicitis. Appendectomy:
  • Wound infection: 3.3%–10.3%
  • Pelvic/abdominal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease: 9.4%
  • Stump appendicitis Stump Appendicitis Appendectomy: if appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy was not completely removed, leaving more than 0.5 cm (0.2 in) stump

Differential Diagnosis

Gastrointestinal

• Gastroenteritis Gastroenteritis Gastroenteritis is inflammation of the stomach and intestines, commonly caused by infections from bacteria, viruses, or parasites. Transmission may be foodborne, fecal-oral, or through animal contact. Common clinical features include abdominal pain, diarrhea, vomiting, fever, and dehydration. Gastroenteritis: acute self-limited viral illness presenting with abdominal pain Abdominal Pain Acute Abdomen, vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia, and diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea. Imaging and labs may be largely normal. Condition is treated supportively with bowel rest and intravenous hydration.
• Mesenteric lymphadenitis Mesenteric Lymphadenitis Inflammation of lymph nodes in the mesentery. Pediatric Gastrointestinal Abnormalities: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of mesenteric lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy associated with acute or chronic abdominal pain Abdominal Pain Acute Abdomen. Mesenteric lymphadenitis Mesenteric Lymphadenitis Inflammation of lymph nodes in the mesentery. Pediatric Gastrointestinal Abnormalities commonly localizes to RLQ because of a large number of lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy in that area. Computed tomography scan/US will show lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy.
• Epiploic appendagitis: ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage/infarction of the colonic fatty appendages. Epiploic appendagitis presents with acute or subacute lower abdominal pain Abdominal Pain Acute Abdomen. Computed tomography scan can confirm the diagnosis. Usually, this self-limited illness is treated with oral anti-inflammatory medications.
• Meckel’s diverticulitis Diverticulitis Inflammation of a diverticulum or diverticula. Diverticular Disease: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of Meckel’s diverticulum Diverticulum A pouch or sac opening from the colon. Diverticular Disease. The condition may be impossible to clinically distinguish from acute appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis as the pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways is similar; however, it may be more central or left-sided. Occasionally, there is a history of intermittent lower gastrointestinal bleeding Gastrointestinal bleeding Gastrointestinal bleeding (GIB) is a symptom of multiple diseases within the gastrointestinal (GI) tract. Gastrointestinal bleeding is designated as upper or lower based on the etiology’s location to the ligament of Treitz. Depending on the location of the bleeding, the patient may present with hematemesis (vomiting blood), melena (black, tarry stool), or hematochezia (fresh blood in stools). Gastrointestinal Bleeding. Computed tomography scan may or may not be diagnostic. Sometimes, diagnosis is made during surgery.
• Right-sided diverticulitis Diverticulitis Inflammation of a diverticulum or diverticula. Diverticular Disease: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of colonic diverticula. Usually left-sided, but right-sided presentation can also occur, especially in young patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship and in Asian populations.  Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with RLQ pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and change in bowel habits. Diagnosis is made by CT scan.
• Terminal ileitis: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the terminal ileum Ileum The distal and narrowest portion of the small intestine, between the jejunum and the ileocecal valve of the large intestine. Small Intestine: Anatomy that can have an antecedent history of abdominal cramping Abdominal cramping Norovirus, weight loss Weight loss Decrease in existing body weight. Bariatric Surgery, and diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea. The ileitis may be non-specific, due to Crohn’s disease or Yersinia Yersinia Yersinia is a genus of bacteria characterized as gram-negative bacilli that are facultative anaerobic with bipolar staining. There are 2 enteropathogenic species that cause yersiniosis, Y. enterocolitica and Y. pseudotuberculosis. Infections are manifested as pseudoappendicitis or mesenteric lymphadenitis, and enterocolitis. Yersinia spp./Yersiniosis infection. Diagnosis is made acutely by CT scan. Colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening (Crohn’s) and serum antibody titers ( Yersinia Yersinia Yersinia is a genus of bacteria characterized as gram-negative bacilli that are facultative anaerobic with bipolar staining. There are 2 enteropathogenic species that cause yersiniosis, Y. enterocolitica and Y. pseudotuberculosis. Infections are manifested as pseudoappendicitis or mesenteric lymphadenitis, and enterocolitis. Yersinia spp./Yersiniosis) can help establish the etiology.

Genitourinary

• Right ureteric colic: obstructive stone in the right ureter that presents as intermittent (colicky) pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways of the right flank Right Flank Surgical Anatomy of the Abdomen/ groin Groin The external junctural region between the lower part of the abdomen and the thigh. Male Genitourinary Examination. Urinalysis Urinalysis Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically. Urinary Tract Infections (UTIs) in Children will show the presence of red blood cells Red blood cells Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology. Diagnosis is established by non-contrast CT scan.
• Urinary tract Urinary tract The urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra. Urinary Tract: Anatomy infection: bacterial infection of the urinary tract Urinary tract The urinary tract is located in the abdomen and pelvis and consists of the kidneys, ureters, urinary bladder, and urethra. The structures permit the excretion of urine from the body. Urine flows from the kidneys through the ureters to the urinary bladder and out through the urethra. Urinary Tract: Anatomy in the form of cystitis Cystitis Inflammation of the urinary bladder, either from bacterial or non-bacterial causes. Cystitis is usually associated with painful urination (dysuria), increased frequency, urgency, and suprapubic pain. Urinary Tract Infections (UTIs) ( bladder Bladder A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination. Pyelonephritis and Perinephric Abscess infection) or right-sided acute pyelonephritis Acute pyelonephritis Inflammation of the kidney involving the renal parenchyma (the nephrons); kidney pelvis; and kidney calices. It is characterized by abdominal pain; fever; nausea; vomiting; and occasionally diarrhea. Imaging of the Urinary System (kidney involvement). Presents with suprapubic pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and dysuria Dysuria Painful urination. It is often associated with infections of the lower urinary tract. Urinary Tract Infections (UTIs) ( cystitis Cystitis Inflammation of the urinary bladder, either from bacterial or non-bacterial causes. Cystitis is usually associated with painful urination (dysuria), increased frequency, urgency, and suprapubic pain. Urinary Tract Infections (UTIs)) or right costovertebral angle tenderness and fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever ( pyelonephritis Pyelonephritis Pyelonephritis is infection affecting the renal pelvis and the renal parenchyma. This condition arises mostly as a complication of bladder infection that ascends to the upper urinary tract. Pyelonephritis can be acute or chronic (which results from persistent or chronic infections). Typical acute symptoms are flank pain, fever, and nausea with vomiting. T Pyelonephritis and Perinephric Abscess). Diagnosis is made by urinalysis Urinalysis Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically. Urinary Tract Infections (UTIs) in Children and CT scan.

Gynecologic

• Right-sided ectopic pregnancy Ectopic pregnancy Ectopic pregnancy refers to the implantation of a fertilized egg (embryo) outside the uterine cavity. The main cause is disruption of the normal anatomy of the fallopian tube. Ectopic Pregnancy: pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care in the right fallopian tube Fallopian Tube A pair of highly specialized canals extending from the uterus to its corresponding ovary. They provide the means for ovum transport from the ovaries and they are the site of the ovum’s final maturation and fertilization. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells. Uterus, Cervix, and Fallopian Tubes: Anatomy. Presents with right-sided abdominal pain Abdominal Pain Acute Abdomen. When ruptured, can present with fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock, and peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury. Usually, there is a history of a missed menstrual period. Findings include a positive pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care test and pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with cervical manipulation (pelvic exam). Diagnosis is confirmed with pelvic US.
• PID PID Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and gardnerella vaginalis. Pelvic Inflammatory Disease: sexually transmitted infection Sexually Transmitted Infection Sexually transmitted infections (STIs) are infections that spread either by vaginal intercourse, anal sex, or oral sex. Symptoms and signs may include vaginal discharge, penile discharge, dysuria, skin lesions (e.g., warts, ulcers) on or around the genitals, and pelvic pain. Some infections can lead to infertility and chronic debilitating disease. Sexually Transmitted Infections (STIs) involving internal reproductive organs, usually in a young adult woman. Pelvic inflammatory disease Pelvic inflammatory disease Pelvic inflammatory disease (PID) is defined as a polymicrobial infection of the upper female reproductive system. The disease can affect the uterus, fallopian tubes, ovaries, and adjacent structures. Pelvic inflammatory disease is closely linked with sexually transmitted diseases, most commonly caused by Chlamydia trachomatis, Neisseria gonorrhoeae, and Gardnerella vaginalis. Pelvic Inflammatory Disease presents with lower abdominal pain Abdominal Pain Acute Abdomen (mostly bilateral), fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and vaginal discharge. Diagnosis is established with pelvic exam and US.
• Ovarian and fallopian tube Fallopian Tube A pair of highly specialized canals extending from the uterus to its corresponding ovary. They provide the means for ovum transport from the ovaries and they are the site of the ovum’s final maturation and fertilization. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells. Uterus, Cervix, and Fallopian Tubes: Anatomy torsion: causes acute ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage of the ovary/ fallopian tube Fallopian Tube A pair of highly specialized canals extending from the uterus to its corresponding ovary. They provide the means for ovum transport from the ovaries and they are the site of the ovum’s final maturation and fertilization. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells. Uterus, Cervix, and Fallopian Tubes: Anatomy. Torsion presents with abdominal pain Abdominal Pain Acute Abdomen (RLQ if on the right), fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics/ vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia. When suspected, a Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) pelvic US (looking at the blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure) should be performed. The condition can affect females of both adult and pediatric age.
• Ruptured ovarian cyst (right): fluid or blood released from the cyst causes peritoneal irritation and acute onset of RLQ abdominal pain Abdominal Pain Acute Abdomen. Diagnosis is made by pelvic US.