Adverse events
| Event | No. |
|---|---|
| Prolonged respiratory suppression (>20 seconds) | 39 (1.9%) |
| Minimal respiratory suppression (10–19 seconds) | 119 (5.9%) |
| Hyperventilation (>25/min) | 34 (1.7%) |
| Other | 53 (2.6%) |
| Nausea/vomiting | 11 (0.5%) |
| Anxiety/funny feeling | 7 (0.3%) |
| Agitation | 6 (0.3%) |
| Hypertension | 5 (0.2%) |
| Numbness/tingling | 4 (0.2%) |
| Blurry vision | 4 (0.2%) |
| Decreased/impaired level of consciousness | 4 (0.2%) |
| Limb jerking/tremor | 2 (0.1%) |
| Seizure | 2 (0.1%) |
| Taste disturbance | 2 (0.1%) |
| TIA-like symptoms | 2 (0.1%) |
| Bradycardia to asystole | 1 (0.05%) |
| Dyspnea | 1 (0.05%) |
| Desaturation to 80 seconds | 1 (0.05%) |
| Chest tightness | 1 (0.05%) |
| Respiratory insufficiency | 1 (0.05%) |
| Could not tolerate mask | 1 (0.05%) |
| Headache | 1 (0.05%) |
| Claustrophobia | 1 (0.05%) |
| Severity | |
| Mild | 35 (1.7%) |
| Moderate | 10 (0.5%) |
| Severe | 7 (0.3%) |
| Event required termination of study | 12 |