Death Diagnosis

Question 1

Definition?

Answer 1

Irreversible loss of the capacity to breath combined with the irreversible loss of the capacity for consciousness

Question 2

Criteria for cardiac death: Pre-conditions?

Answer 2

1st: should be established from the history that the patients suffered from a simultaneous onset of apnoea and unconsciousness.
2nd: should be established that patient is DNACPR or CPR attempts have failed, or life sustaining treatment has been withdrawn.

Question 3

Criteria for cardiac death: Tests?

Answer 3

Patient should be observed for a minimum of 5 mins for an absence of a central pulse on palpation and an absence of heart and breath sounds on auscultation. (Restart 5 mins if any activity)

In hopsital setting:
o Asystole on continuous ECG
o Absence of pulsatile flow on direct arterial pressure monitoring
o Absence of contractile activity on echocardiography

Following this diagnosis of brainstem death is made by examining for lack of pupillary light reflexes, corneal reflexes, and motor response to supraorbital pressure.

—> then time of death is completed.

Question 4

Criteria for brainstem death: Pre-condition?

Answer 4

There must be no doubt that the brainstem death is due to irreversible condition of known aetiology.

Exclude reversible causes of coma: 4T’s 4H’s

Question 5

Criteria for brainstem death:

Answer 5

Diagnosis must be made by two clinicians, one of whom must be a consultant. Patients will necessarily be on ICU as their ventilation will be supported.

Absence of brainstem reflexes:
o pupils are fixed and do not respond to light (CNII & III)
o No corneal reflex (CNV & VII)
o Oculovestibular reflexes absent (CNV & VIII)
o No motor responses within the cranial nerve distribution by stimulation of any somatic area (VII)
o No motor response to supraorbital pressure within cranial nerve or somatic distribution (CNV &VII)
o No cough reflex to bronchial stimulation, or gag reflex to pharyngeal stimulation (CNIX &X)

Final test is to test brainstem response to hypercarbia:
o Ensure patient is oxygenating at 100% (set ventilator to 100%O2 for a few mins prior to testing)
o Reduce minute volume to allow CO2 level to gradually rise. Once it has reached >6kPa confirmed by ABG, disconnect the ventilator to render the patient apneic.
o Oxygenation is maintained by mass flow (connect the patient to a water’s anaesthetic circuit with 100% O2)
o Observe patient for signs of respiratory activity, if none perform ABG at 5 mins, confirm CO2 has risen by a further 0.5 kPa  if so patient has passed test
o Reattach ventilator, restablish normal ventilation.

• Tests must be completed again in full by the same two clinicians, diagnose brainstem death on completion of second set of tests.
• These criteria are applicable to anyone over the age of 2 months. Must not be carried out by a doctor with a conflict of interest (ie a member of the transplant team). Legal time of death is after completion of first set of tests not second.