Brain Death Determination – Special Devices (ICU and Brain Death Determination)

00:00 One of the unpleasant aspects of intensive care treatment is that, there's a reasonably high mortality rate in the intensive care unit. And there needs to be a way of determining brain death. We have very sophisticated means by which we can keep the heart functioning and so, pure heart death is now not looked upon as the only means by which we determine death. But each country has its own legal criteria for determining neurologic determination of death or NDD. And I've only mentioned the Canadian criteria here, you need to check your own country and make sure your criteria are understood. So in Canada, the minimal clinical criteria for neurologic determination of death are an Established Etiology, so you have to know what's causing the problem and be able to say that that particular etiology is capable of causing brain death. Deep Unresponsive Coma with bilateral absence of motor responses, excluding spinal reflexes, so some reflexes will remain but no response to pain or position sense, or any of the usual things that one responds to when normal. There have to be absent brain stem reflexes. So that may be response to corneal stimulation, loss of gag reflex, loss of cough reflex. So the corneal response goes both eyes.

01:41 Pupillary responses to light, so the pupil changing size according to different levels of light.

01:48 The vestibulo-ocular reflex can be assessed by putting cold water into one ear canal.

01:53 This should exhibit a horizontal nystagmus away from water filled ear.

01:59 If there is no nystagmus visulized by the examiner, the reflex is not intact.

02:03 An apnea test is done. The patient is discontinued from the ventilator, but this can only occur in a situation where there are no muscle relaxants on board and where there is virtually no narcotic on board. You turn off the ventilator and you give the patient a period of time, usually between, usually around 3 minutes to see if they make any breathing effort. And then there has to be absent confounding factors as I've indicated.

02:31 So, sedation, deep sedation, muscle relaxation, heavy use of narcotics can't be in place at the time that one determines neurologic death. So at the time of assessment of NDD, the following confounding factors preclude the clinical diagnosis.

02:49 So if any of these things are actually in place, you cannot legally, at least in Canada, make a neurological determination of death. So there's unresuscitated shock, or if temperature is low, below 34 degrees and it's a bit of a joke, but it's a legal requirement, that you cannot be cold and die, you must be warm and die. Severe metabolic disorders capable of causing a reversible coma must be excluded. Severe metabolic disorders including glucose-electrolyte and unusual electrolytes such as phosphate, calcium, magnesium, all need to be checked and it has to be determined that they are at normal levels.

03:37 There has to be an examination to make sure that there aren't inborn errors of metabolism that might mimic death or coma. And you have to make sure that you're absolutely convinced that everything that could mimic coma or death has been eliminated before you can make the neurologic determination of death. So, certainly things like drug intoxication, alcohol, barbiturates have to be absent at the time you make this determination. So, in summary, in this lecture we've discussed the intensive care unit, the various forms of intensive care unit that are present in our society now. We've talked about the training required to become an intensive care physician and the special skills that nurses require to work in intensive care. We've talked about some of the diagnoses that are critical in the intensive care unit.

04:37 And some of the equipment that's used to try to support patients in the ICU.

04:43 And finally, we talked about the neurologic determination of death, which is a legal definition of death, and is determined by individuals' countries, and varies from one place to another, a little bit, not a lot, but a little bit. So it's important that you understand your own country's neurologic definition of death.