Effect of Nalbuphine on Hemodynamic Response During Laryngoscopy and Intubation

Overview

Laryngoscopy and placement of a breathing tube during general anesthesia can cause temporary increases in blood pressure and heart rate. These changes may be harmful in some patients. Nalbuphine is an opioid pain medicine that may reduce these cardiovascular responses. This study evaluated whether intravenous nalbuphine, given before anesthesia induction, reduces changes in mean arterial blood pressure during laryngoscopy and orotracheal intubation compared with placebo (normal saline). Adult patients undergoing elective surgery under general anesthesia were randomly assigned to receive either nalbuphine or placebo before anesthesia. Blood pressure was measured before drug administration, during intubation, and for several minutes afterward. The results of this study may help guide safe medication use to maintain blood pressure stability during airway management.

Laryngoscopy and orotracheal intubation are essential components of general anesthesia but are associated with a sympathoadrenal stress response caused by stimulation of the laryngeal and pharyngeal structures. This response may result in transient hypertension and tachycardia due to catecholamine release. Although often well tolerated in healthy individuals, these hemodynamic changes can be undesirable and potentially harmful, particularly in patients with limited cardiovascular reserve. Opioids have been widely used to attenuate the hemodynamic response to airway manipulation. Nalbuphine is a synthetic opioid with kappa receptor agonist and mu receptor antagonist properties. It provides analgesia with a ceiling effect on respiratory depression and has a lower risk of certain opioid-related adverse effects compared with pure mu agonists. Despite these potential advantages, data regarding the effectiveness of nalbuphine in attenuating intubation-related hemodynamic responses remain limited. This prospective, randomized, controlled trial was conducted at Hayatabad Medical Complex, Peshawar, Pakistan, between March 2024 and December 2024. Adult patients aged 18 to 60 years with American Society of Anesthesiologists (ASA) physical status I, scheduled for elective surgery under general anesthesia requiring orotracheal intubation, were enrolled. Patients with anticipated difficult airways, cardiovascular disease, hypertension, hepatic or renal disease, pregnancy, opioid allergy, or use of interacting medications were excluded. Eligible participants were randomly allocated into two groups. The intervention group received intravenous nalbuphine at a dose of 0.2 mg/kg, while the control group received an equivalent volume of normal saline. The study drug was administered five minutes before induction of anesthesia. Anesthesia induction was standardized using propofol and atracurium, followed by Macintosh laryngoscopy and orotracheal intubation performed by experienced anesthetists. Hemodynamic parameters were recorded at baseline, three minutes after administration of the study drug, immediately after intubation, and at one-minute intervals for five minutes following intubation. The primary outcome measure was mean arterial pressure after laryngoscopy and intubation. Adverse events, including bradycardia, hypotension, nausea, respiratory depression, and other complications, were monitored intraoperatively. The purpose of this study was to determine whether nalbuphine premedication provides better attenuation of the hemodynamic response to laryngoscopy and intubation compared with placebo in healthy adult patients undergoing elective surgery.