Table 3. Apnea testing in countries in Asia and the Pacific.
| Examination component | Number of protocols (n=24) |
|---|---|
| Preparation for testing | |
| Check for spontaneous breathing before conducting apnea testing | 2 (8) |
| Complete the clinical examination for the determination of BD/DNC before conducting apnea testing | 9 (38) |
| Obtain an arterial blood gas reading before apnea testing | 13 (54) |
| Review the PaCO2 value before apnea testing | |
| PaCO2 should be normal | 1 (8) |
| PaCO2 should be 35–45 mm Hg | 7 (54) |
| PaCO2 should be ~40 mm Hg | 1 (8) |
| PaCO2 should be ≥40 mm Hg | 3 (23) |
| PaCO2 should be 40–45 mm Hg | 1 (8) |
| Review the pH value before apnea testing | |
| Target not stated | 12 (92) |
| pH should be normal | 1 (8) |
| Factors that may preclude apnea testing | |
| Not stated | 22 (92) |
| High-level spinal cord injury | 1 (4) |
| Hypoxia | 1 (4) |
| Preoxygenation | |
| Not stated | 5 (21) |
| 5 min of FiO2=100% | 1 (4) |
| 10 min of FiO2=100% | 15 (63) |
| 15 min of FiO2=100% | 1 (4) |
| PaO2 ≥200 mm Hg | 5 (21) |
| Decrease respiratory rate by 2 breaths/min and increase FiO2 to 100% | 1 (4) |
| Apnea testing procedure | |
| Not stated | 3 (13) |
| Not described in detail | 2 (8) |
| Administer oxygen (amount not specified) | 1 (4) |
| Administer oxygen at 4–6 L/min | 2 (8) |
| Administer oxygen at 6 L/min | 11 (46) |
| Administer oxygen at 6–8 L/min | 1 (4) |
| Administer oxygen at 10 L/min | 1 (4) |
| Disconnect the ventilator | 16 (67) |
| Place a catheter above the carina | 8 (33) |
| Place a catheter 1 cm beyond the endotracheal tube | 1 (4) |
| Turn off backup ventilation if testing is done on the ventilator | 1 (4) |
| Utilize CPAP | 3 (13) |
| Utilize a T-piece | 5 (21) |
| Reasons to end apnea testing | |
| Not stated | 9 (38) |
| 8 min has passed | 2 (8) |
| 10 min has passed | 6 (25) |
| Dysrhythmia | 7 (29) |
| Hemodynamic disturbance | 3 (13) |
| Hypotension (general) | 3 (13) |
| Hypotension with SBP <90 mm Hg | 5 (21) |
| Hypoxia (general) | 3 (13) |
| Hypoxia with saturation <85% | 4 (17) |
| Hypoxia with saturation <90% | 1 (4) |
| Hypoxia with saturation <91% | 1 (4) |
| Spontaneous breathing | 10 (42) |
| Target value of apnea testing | |
| Not stated | 5 (21) |
| PaCO2 ≥50 mm Hg | 2 (8) |
| PaCO2 ≥55 mm Hg | 1 (4) |
| PaCO2 >60 mm Hg | 4 (17) |
| PaCO2 ≥60 mm Hg | 12 (50) |
| PaCO2 increase of 10–15 mm Hg above baseline | 1 (4) |
| PaCO2 increase of ≥20 mm Hg above baseline | 12 (50) |
| pH target provided | 0 (0) |
| Next steps if apnea testing is aborted and no breaths were seen but the PaCO2 target value was not reached | |
| Not stated | 13 (54) |
| Perform an ancillary test | 9 (38) |
| Perform a blood flow | 2 (8) |
| Repeat the test after 3 hours | 1 (4) |
| Repeat the test with CPAP | 2 (8) |
| Repeat the test for longer | 1 (4) |
| Repeat the test with a higher oxygen flow rate | 2 (8) |
Data are n (%).
BD/DNC: brain death/death by neurologic criteria, CPAP: continuous positive airway pressure, SBP: systolic blood pressure.