The effect of low-dose ketamine on fentanyl-induced respiratory depression.
This study evaluated if adding low-dose ketamine to fentanyl could offer a haemodynamically stable drug combination with little respiratory side-effects. Eight healthy, consenting male volunteers received in a random, cross-over and double-blind fashion both fentanyl 2 micrograms.kg-1 + ketamine 0.25 mg.kg-1 and fentanyl 2 micrograms.kg-1 + placebo. The fentanyl and placebo reduced minute ventilation, alveolar ventilation and oxygen consumption (p < 0.05), with little effect on haemodynamics. After fentanyl and ketamine, the decrease in minute ventilation and alveolar ventilation was attenuated compared to the placebo-containing combination (p < 0.05), but with a simultaneous increase in oxygen consumption (p < 0.05) and stimulation of haemodynamics (p < 0.05). Both treatments decreased oxygen saturation and arterial oxygen pressure similarly. Ketamine thus attenuated the fentanyl-induced reduction in ventilation without preventing the decrease in blood oxygenation. In conclusion, combining low-dose ketamine to fentanyl offers no benefits in terms of preventing respiratory depression.
Mildh
L
L
Department of Anaesthesiology, Helsinki University Hospital, Töölö Hospital, Finland.
Taittonen
M
M
Leino
K
K
Kirvelä
O
O
D000328:Adult; D000701:Analgesics, Opioid / Q000009:adverse effects*; D000778:Anesthetics, Dissociative / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005283:Fentanyl / Q000009:adverse effects*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007649:Ketamine / Q000627:therapeutic use*; D008297:Male; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects; D010991:Plethysmography; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000517:prevention & control*
D000701:Analgesics, Opioid; D000778:Anesthetics, Dissociative; D007649:Ketamine; D010100:Oxygen; D005283:Fentanyl