Apnea test for determination of clinical brain

 

 

APNEA TEST FOR DETERMINATION OF CLINICAL BRAIN 

DEATH 

 

It is recommended that the apnea test be performed as follows: 

 

1. Prerequisites: 

•

 

•

 

•

 

•

 

Core 

Temperature 

  36.5

°

C or 97

°

F 

Systolic blood pressure  

 

90 mm Hg 

Corrected diabetes insipidus (Positive fluid balance) 

Normal 

PCO

2

 (Arterial PCO

2

 of 35-45 mm Hg) 

•

   

2.  Preoxygenate with 100% O

2

 for 30 minutes 

 

3.  Connect a pulse oximeter and disconnect the ventilator 

 

4.  Place a nasal cannula at the level of the carina and deliver 100% O

2

, 8 L per 

minute 

 

5.  Look closely for respiratory movements (abdominal or chest excursions that 

produce adequate tidal volumes) 

 

6. Measure PO

2

, PCO

2

, and pH after 10 minutes and reconnect the ventilator 

 

7. If respiratory movements are absent and arterial PCO

2

 is 60 mm Hg (option: 

20 mm Hg increase in PCO

2

 over a baseline normal PCO

2

), the apnea test 

result is positive (supports the diagnosis of brain death) 

 

Connect the ventilator if during testing the systolic blood pressure 

becomes < 90 mm Hg or the pulse oximeter indicates significant 

desaturation and cardiac arrhythmias are present: immediately draw 

an arterial blood sample and analyze ABG! 

 

8. If PCO

2

 is 60 mm Hg or PCO

2

 increase is > 20 mm Hg over baseline normal 

PCO

2

, the apnea test is positive [supports the clinical diagnosis of brain 

death] 

 

9. If the PCO

2

 is < 60 mm Hg or PCO

2

 increase is < 20 mm Hg over baseline 

normal  PCO

2

, the result is indeterminate and an additional confirmatory test 

can be considered. 

Summary of the American Academy of Neurology Practice for determining Brain Death in Adults 

 

 

© 2001