Spinal cord injury (SCI) reduces anesthetic requirements and stress hormonal responses. Anesthetic requirements and stress hormone response are compared in SCI patients undergoing anesthesia with sevoflurane supplemented with clinically equivalent doses of either N2O or remifentanil.

Nitrous oxide (N2O) is often used for anesthetic adjuvant, but may be associated with side effects and toxicities. Remifentanil shares characteristics with N2O, including anesthetic-reducing and antinociceptive effects and a rapid recovery. Anesthetic requirements and stress hormone response in SCI patients undergoing anesthesia with sevoflurane supplemented with clinically equivalent doses of either N2O or remifentanil. Forty-five SCI patients scheduled to undergo pressor sore surgery below the level of the injury are randomly allocated to receive either sevoflurane alone (control, n=15), or combined with 67% N2O (n=15) or target-controlled infusions of 1.37 ng/mL remifentanil (n=15). Sevoflurane concentration is titrated to maintain a Bispectral Index (BIS) value of 40-50. Measurements include end-tidal sevoflurane concentrations, mean arterial blood pressure (MAP), heart rate (HR), and plasma catecholamine and cortisol concentrations.

Inclusion Criteria:

• ASA physical status II, with chronic, clinically complete cord injuries scheduled for a surgery for pressure sore below the level of the neurologic lesion under general anesthesia.

Exclusion Criteria:

• Cardiovascular, pulmonary, or metabolic diseases. Patients who took medications that would influence autonomic or cardiovascular responses to the surgery

ASA physical status II, with chronic, clinically complete cord injuries scheduled for a surgery for pressure sore below the level of the neurologic lesion under general anesthesia.