Determination of Brain Determination of Brain DeathDeath

Donn Dexter, MD, FAANDonn Dexter, MD, FAAN

Douglas T. Miller SymposiumDouglas T. Miller SymposiumApril 29, 2011April 29, 2011

DisclosuresDisclosures

• Full time physician at Luther-Full time physician at Luther-Midelfort Mayo Heath System, Eau Midelfort Mayo Heath System, Eau Claire, Wisconsin.Claire, Wisconsin.

• No financial relationships or interests No financial relationships or interests that pertain to organ donation.that pertain to organ donation.

Outline Outline

• What is Brain Death?What is Brain Death?

• How Do You Declare Brain Death?How Do You Declare Brain Death?– Clinical EvaluationClinical Evaluation– Neurologic EvaluationNeurologic Evaluation– Apnea TestApnea Test– Ancillary TestsAncillary Tests

• ConclusionConclusion

Determination of Brain Determination of Brain DeathDeath• Uniform Determination of Death Act Uniform Determination of Death Act

(UDDA). (UDDA).

• An individual who has sustained either: An individual who has sustained either: 1) irreversible cessation of circulatory 1) irreversible cessation of circulatory and respiratory function or 2) and respiratory function or 2) irreversible cessation of all function of irreversible cessation of all function of the entire brain, including brain stem, is the entire brain, including brain stem, is dead.dead.

• A determination of death must be made A determination of death must be made with acceptable medical standards.with acceptable medical standards.

Determination of Brain Determination of Brain DeathDeath

• The American Academy of Neurology The American Academy of Neurology (AAN) delineated the medical (AAN) delineated the medical standards for brain death in 1995. standards for brain death in 1995.

• This practice parameter was This practice parameter was reviewed in 2010 (Neurology 74, June reviewed in 2010 (Neurology 74, June 8, 2010). 8, 2010).

Determination of Brain Determination of Brain DeathDeath• Question for the 2010 AAN review: Are Question for the 2010 AAN review: Are

there patients who fulfill the criteria of there patients who fulfill the criteria of brain death who recover brain function?brain death who recover brain function?

• In adults, the recovery of brain function In adults, the recovery of brain function has not been reported after clinical has not been reported after clinical declaration of brain death using the 1995 declaration of brain death using the 1995 AAN brain death criteria.AAN brain death criteria.

Determination of Brain Determination of Brain DeathDeath• Determination of Brain Death – 4 StepsDetermination of Brain Death – 4 Steps

1) Establish irreversible and proximate 1) Establish irreversible and proximate cause of coma. cause of coma.

2) Achieve normal core temperature. 2) Achieve normal core temperature.

3) Achieve normal systolic blood 3) Achieve normal systolic blood pressure. pressure.

4) Perform neurologic examination. 4) Perform neurologic examination.

The Clinical EvaluationThe Clinical Evaluation

• Establish Irreversible and Proximate Establish Irreversible and Proximate Cause of ComaCause of Coma– Usually obvious. Usually obvious. – Exclude drugs (including alcohol Exclude drugs (including alcohol

above legal limit). above legal limit). – No recent or persistent No recent or persistent

neuromuscular blocking agents (train neuromuscular blocking agents (train of 4 twitches to nerve stimulation). of 4 twitches to nerve stimulation).

– No severe electrolyte, acid-base, or No severe electrolyte, acid-base, or endocrine disturbance (ABGs, lytes, endocrine disturbance (ABGs, lytes, chem panel). chem panel).

The Clinical Evaluation The Clinical Evaluation (cont.)(cont.)

• Achieve Normal Core TemperatureAchieve Normal Core Temperature– Core body temperature > 36 Core body temperature > 36

degrees C. degrees C. – Important for apnea test. Important for apnea test. – Warming blanket and warmed IV Warming blanket and warmed IV

fluids may be required. fluids may be required.

The Clinical Evaluation The Clinical Evaluation (cont.)(cont.)• Achieve Normal Systolic Blood PressureAchieve Normal Systolic Blood Pressure

– Neurologic examination usually reliable Neurologic examination usually reliable with systolic BP > 100 mmHg. with systolic BP > 100 mmHg.

– UW-OPO requires systolic BP > 100 UW-OPO requires systolic BP > 100 mmHg. mmHg.

– May require vasopressors to maintain May require vasopressors to maintain adequate BP (dopamine and adequate BP (dopamine and neosynephrine often preferred). neosynephrine often preferred).

The Clinical Evaluation The Clinical Evaluation (cont.)(cont.)• Perform Neurologic ExaminationPerform Neurologic Examination

– One examination is sufficient. One examination is sufficient. – Examiner should be intimately Examiner should be intimately

familiar with brain death criteria. familiar with brain death criteria. – Most commonly a critical care Most commonly a critical care

specialist, neurologist, or specialist, neurologist, or neurosurgeon. neurosurgeon.

– Varies by state. Outside WI check Varies by state. Outside WI check with state statute. with state statute.

The Neurologic ExaminationThe Neurologic Examination

• ComaComa– No evidence of responsiveness. No evidence of responsiveness. – No eye opening to noxious stimuli. No eye opening to noxious stimuli. – No motor response to noxious No motor response to noxious

stimuli other than spinally stimuli other than spinally mediated reflexes (may require mediated reflexes (may require expertise to distinguish). expertise to distinguish).

The Neurologic Examination The Neurologic Examination (cont.)(cont.)

• Absence of Brainstem ReflexesAbsence of Brainstem Reflexes– No pupillary response to bright light No pupillary response to bright light

(typically fixed @ 4-9 mm). (typically fixed @ 4-9 mm). – Absent corneal reflex. Absent corneal reflex. – Absent facial muscle movement to Absent facial muscle movement to

noxious stimulus. noxious stimulus. – Absent pharyngeal and tracheal Absent pharyngeal and tracheal

reflexes (gag and deep suction).reflexes (gag and deep suction).

The Neurologic The Neurologic ExaminationExamination (cont.)(cont.)

• Absent Brainstem Reflexes (cont.)Absent Brainstem Reflexes (cont.)– Absent eye movements to oculocephalic Absent eye movements to oculocephalic

testing (doll’s eyes test); integrity of testing (doll’s eyes test); integrity of cervical spine must be certain. cervical spine must be certain.

– Oculovestibular testing (cold water Oculovestibular testing (cold water calorics) – Head of bed 30 degrees, 50 calorics) – Head of bed 30 degrees, 50 mL ice water irrigation of each patent mL ice water irrigation of each patent ear canal with 5 minutes observation ear canal with 5 minutes observation and 5 minutes between tests. and 5 minutes between tests.

The Apnea TestThe Apnea Test

• PreconditionsPreconditions– Normothermia. Normothermia. – Systolic BP > 100 mm Hg. Systolic BP > 100 mm Hg. – Euvolemia (positive fluid balance). Euvolemia (positive fluid balance). – Eucapnia (PaCO2 35-45 mmHg). Eucapnia (PaCO2 35-45 mmHg). – No evidence for CO2 retention No evidence for CO2 retention

(COPD, severe obesity, severe OSA). (COPD, severe obesity, severe OSA).

The Apnea Test (cont.)The Apnea Test (cont.)• Preoxygenate for 10 minutes to PaO2 Preoxygenate for 10 minutes to PaO2

>200 mm Hg. >200 mm Hg.

• Reduce ventilation frequency to 10 Reduce ventilation frequency to 10 bpm and PEEP to 5 cm H2O. bpm and PEEP to 5 cm H2O.

• If pulse oximetry remains > 95%, If pulse oximetry remains > 95%, check baseline ABG. check baseline ABG.

• Disconnect ventilator and preserve Disconnect ventilator and preserve oxygenation with 100% O2 @ 6-10 oxygenation with 100% O2 @ 6-10 lpm via catheter through the ET at lpm via catheter through the ET at level of carina. level of carina.

The Apnea Test (cont.)The Apnea Test (cont.)

• Watch closely for respiratory Watch closely for respiratory movements (abdominal or chest movements (abdominal or chest excursions). excursions).

• If no respiratory efforts, draw ABGs at If no respiratory efforts, draw ABGs at 3-5 minutes and again at 7-10 minutes. 3-5 minutes and again at 7-10 minutes.

• If arterial PaCO2 is 60 mm Hg or If arterial PaCO2 is 60 mm Hg or greater or if >20 mmHg over baseline, greater or if >20 mmHg over baseline, the test is positive. the test is positive.

• If inconclusive, may extend to 10-15 If inconclusive, may extend to 10-15 minutes if clinically stable. minutes if clinically stable.

The Apnea Test (cont.)The Apnea Test (cont.)

• Abort Apnea Test for: Abort Apnea Test for: – Spontaneous respiratory effort. Spontaneous respiratory effort. – Significant cardiac ectopy. Significant cardiac ectopy. – Pulse oximetry <90%. Pulse oximetry <90%. – Systolic blood pressure < 90 Systolic blood pressure < 90

mmHg. mmHg.

Ancillary TestingAncillary Testing

• EEG, TCD, CTA, MRI/MRA, cerebral EEG, TCD, CTA, MRI/MRA, cerebral angiography, and nuclear scans have angiography, and nuclear scans have all been used to confirm brain death. all been used to confirm brain death.

• Used when standard testing Used when standard testing impossible or inconclusive (i.e. impossible or inconclusive (i.e. aborted apnea test). aborted apnea test).

• EEG, cerebral angiography, and EEG, cerebral angiography, and nuclear scan preferred. nuclear scan preferred.

DocumentationDocumentation

• Follow checklist closely!Follow checklist closely!

• Time of death is the time PaCO2 Time of death is the time PaCO2 reached target. reached target.

• If apnea test aborted, the time of If apnea test aborted, the time of death is the time ancillary test is death is the time ancillary test is interpreted. interpreted.

ConclusionConclusion

• Have a clear and available protocol Have a clear and available protocol for the determination of brain death for the determination of brain death at your institution (UW-OPO has a at your institution (UW-OPO has a good one). good one).

• Review it regularly; test it formally. Review it regularly; test it formally.

• Follow it closely. Follow it closely.