Apnoea Test

News: The Supreme Court of India observed that a plea raised concerns that the apnoea test may not conclusively determine brain death.

About Apnoea Test

• The apnoea test is considered an essential clinical test for determining brain death by assessing loss of brainstem function.
• Aim: The aim is to confirm the absence of brainstem function by observing breathing response when carbon dioxide level rises.
• Indicators: Absence of breathing effort at a carbon dioxide level of about 60 mmHg or a 20 mmHg rise from baseline supports brain death, while any breathing effort rules it out.
• Key aspects:
  • Essential yet difficult test: It is considered a necessary condition for brain death, but it is difficult, lengthy, and may cause complications.
  • Prerequisites before test: The test requires stable conditions such as normal body temperature, proper oxygen level, normal carbon dioxide level, stable blood pressure, and absence of drugs affecting respiration.
  • Procedure and threshold: The test is considered positive when no breathing effort is seen at a carbon dioxide level of about 60 mmHg or a 20 mmHg rise from baseline.
  • Monitoring and Stopping Conditions: The test must be stopped if blood pressure falls below 90 mmHg, oxygen levels drop significantly, or cardiac arrhythmia occurs.
  • Complications and Risks: The test may cause hypotension, hypoxia, acidosis, pneumothorax, and cardiac complications, which may force stopping the test and affect diagnosis.