Breathing variability during propofol/remifentanil procedural sedation with a single additional dose of midazolam or s-ketamine: a prospective observational study.

Purpose: Regulation of spontaneous breathing is highly complex and may be influenced by drugs administered during the perioperative period. Because of their different pharmacological properties we hypothesized that midazolam and s-ketamine exert different effects on the variability of minute ventilation (MV), tidal volume (TV) and respiratory rate (RR).

Methods: Patients undergoing procedural sedation (PSA) with propofol and remifentanil received a single dose of midazolam (1-3 mg, n = 10) or s-ketamine (10-25 mg, n = 10).