| Decreased metabolic rate and ventilatory requirements |
| Reduced medullary sensitivity to hypercarbia or hypoxia |
| Blunted medullary response to hypercarbia or hypoxia |
| Alteration of neurotransmission within medullary respiratory centre |
| Cortical sedation (suppression of respiratory awareness) |
| Analgesia - reduction of pain-induced respiratory drive |
| Anxiolytic effects |
| Blunted afferent transmission from pulmonary mechanoreceptor to the CNS |
| Vasodilation (improved cardiac function) |
