Comparison between the Hemodynamic Profile with Esmolol versus Morphine as an Adjuvant Agent during Induction of Anesthesia

Abstract

Background: The induction of general anesthesia is a critical phase in anesthetic practice, often associated with significant hemodynamic changes. These changes can lead to complications due to autonomic adrenergic responses. Esmolol, a beta-1 antagonist, is commonly used to blunt these responses, but its availability is limited in some settings. Morphine, a pure mu receptor antagonist, presents a potential alternative.

Objective: This study aimed to compare the efficacy of intravenous esmolol versus intravenous morphine in stabilizing the hemodynamic profile during the induction of general anesthesia.

Methods: This randomized controlled trial was conducted at the Department of Anesthesiology, Combined Military Hospital, from January to June 2023. After obtaining ethical approval and trial registration, 220 ASA-II patients aged 25-55 years scheduled for elective surgeries under general anesthesia were enrolled. Patients were randomized into two groups: Group E (n=110) received 1.5 mg/kg intravenous esmolol three minutes before laryngoscopy and intubation, and Group M (n=110) received 0.1 mg/kg intravenous morphine five minutes before laryngoscopy and intubation. Baseline heart rate, systolic and diastolic blood pressure, and oxygen saturation were recorded after pre-oxygenation with 100% oxygen for three minutes. Post-intubation, the same parameters were measured five minutes after intubation. Statistical analysis was performed using SPSS version 25.0, with independent samples T-tests used to compare means. A p-value of ≤0.05 was considered statistically significant.

Results: The mean age was 39.41 ± 5.13 years in Group E and 39.97 ± 5.08 years in Group M (p=0.414). Mean weight was 68.14 ± 3.88 kg in Group E and 68.08 ± 3.80 kg in Group M (p=0.916). Pre-induction mean heart rate was 71.75 ± 2.33 bpm in Group E and 71.58 ± 2.35 bpm in Group M (p=0.585). Five minutes post-intubation, mean heart rate was significantly lower in Group E (80.73 ± 2.54 bpm) compared to Group M (87.62 ± 2.83 bpm) (p<0.001). Mean systolic blood pressure post-intubation was 132.88 ± 4.65 mm Hg in Group E and 140.25 ± 2.39 mm Hg in Group M (p<0.001). Mean diastolic blood pressure post-intubation was 77.58 ± 2.35 mm Hg in Group E and 85.33 ± 3.71 mm Hg in Group M (p<0.001). Oxygen saturation remained stable in both groups.

Conclusion: Intravenous esmolol is superior to intravenous morphine in blunting the hemodynamic responses to laryngoscopy and intubation, providing a more stable hemodynamic profile during the induction of general anesthesia.