Effect of low-dose ketamine versus fentanyl on attenuating the haemodynamic response to laryngoscopy and endotracheal intubation in patients undergoing general anaesthesia: a prospective, double-blinded, randomised controlled trial

Abstract

Background: The use of drugs to attenuate the haemodynamic response to laryngoscopy and endotracheal intubation is the standard of care during elective surgery. Current evidence is conflicting concerning the best agent and optimal dose for this purpose. In the majority of cases, fentanyl is widely utilized to attenuate haemodynamic responses. Ketamine, an established available drug, has been scarcely studied in this regard at low doses and against varying doses of other common agents.Objective: To compare the overall occurrence of hypertension and tachycardia immediately pre-intubation (post-induction) until 10 minutes post intubation between the study group receiving fentanyl at 1.0 µg/kg and the other receiving ketamine at 0.5 mg/kg, to compare the occurrence of post-induction hypotension and the occurrence of neuropsychiatric phenomena during emergence between the two groups.Methods: One hundred and eight ASA I and II patients aged 18-65 years scheduled for elective surgery under general anaesthesia were randomized into two groups: Control group: received fentanyl 1.0 µg/kg intravenously. Intervention group: received ketamine 0.5 mg/kg intravenously. General anaesthesia was standardized in both groups. The patients and physicians administering anaesthesia were blinded to the study. Haemodynamic responses were evaluated by determining heart rate and blood pressure immediately before laryngoscopy and at 2.5, 5, 7.5 and 10 minutes. Neuropsychiatric phenomena were assessed upon recovery from anaesthesia.Results: One hundred and eight ASA I and II patients scheduled to undergo elective surgery were included in this study, 54 participants (50%) in the fentanyl arm and 54 (50%) in the ketamine arm. Baseline demographic characteristics were similar between the groups. There were more hypertensive episodes in the ketamine arm (11%) compared to the fentanyl arm (1.85%), but not achieving statistical significance: Fisher’s exact test, p=0.06. There was no significant difference in the number of episodes of tachycardia between the Ketamine group 7/54 (13%) and the fentanyl group, 6/54 (11%); x2=0.05, p=0.82. Hypotensive episodes were more common in those who received Fentanyl, 41/54 (76%), compared to ketamine recipients, 21/54 (39%), X2=16.9, p<0.001. The use of Ketamine was associated with less episodes of hypotension, adjusted odds ratio = 0.18 (95% confidence interval 0.07, 0.45).Conclusion: We conclude, based upon findings in this study group, that there is no difference in the occurrence of hypertension with the use ketamine at 0.5 mg/kg in combination with Propofol at 2.0 mg/kg. In this regard, ketamine provides a viable alternative to fentanyl at 1.0 µg/kg for attenuating the pressor response to laryngoscopy and endotracheal intubation. Additionally, our results suggest that ketamine may protect against post-induction (pre-laryngoscopy) hypotension.Keywords: Low-dose ketamine, fentanyl, laryngoscopy, endotracheal, intubation, double-blinded, randomised controlled trial.

Hemodynamic Effects Ketamine versus Ketamine with Thiopental for Patients Undergoing Abdominal Surgery

“…Thiopental can produce effective sedation within one minute, and has a rapid clinical recovery (about 15 min). Thiopental administered intravenously has adequate sedation, faster recovery, and a lower rate of bradycardia and desaturation [17]. However, it has several disadvantages, including decreased arterial pressure, dose-dependent reduction in cardiac output, stroke volume and systemic vascular resistance which associated with a compensatory tachycardia [18].…”

Comparison of the effects of opioid-free anesthesia (OFA) and opioid-based anesthesia (OBA) on postoperative analgesia and intraoperative hemodynamics in patients undergoing spine surgery: A prospective randomized double-blind controlled trial

“…evaluated HD responses before laryngoscopy and at 2.5, 5, 7.5, and 10 min between the ketamine and fentanyl groups. [ 22 ] They found a higher incidence of hypertensive episodes in the ketamine group, though the finding was not statistically significant. The fentanyl-propofol group had more episodes of hypotension compared to the ketamine-propofol group during short emergency surgical procedures.…”

“…Similar results were shown in the literature by other authors. [ 21 22 23 ] Attalla et al . [ 21 ] reported a statistically significant difference between the ketamine and fentanyl groups in terms of HDs, sedation ranking, pain scores, first-call analgesia, and complications, in which the ketamine group was superior to the fentanyl group ( P < 0.05).…”

Cardiorespiratory consequences of attenuated fentanyl and augmented rocuronium dosing during protocolised prehospital emergency anaesthesia at a regional air ambulance service: a retrospective study

“…Indeed, it may be that fentanyl, traditionally added to attenuate the laryngoscopy response, may not be required at all, or for certain patient populations such as burns. It is recognised that the time given to fentanyl to work in a rapid sequence induction is unlikely to be sufficient; indeed a recent study in elective surgical patients showed that ketamine was an alternative to fentanyl alongside propofol for attenuating this response and it resulted in less hypotension [ 19 ].…”