Abstract:
Introduction: Propofol is commonly used intravenous induction
agent which are frequently complicated by peri-induction
hypotension. Reduced Mean Arterial Pressure (MAP) during
anaesthesia contributes to significant postoperative morbidity,
including renal and myocardial injury. Preventive strategies
aimed at maintaining haemodynamic stability during this critical
period are of clinical value. Phenylephrine offers a simple, rapid
option for counteracting propofol-induced vasodilatation.
Aim: To assess effectiveness of i.v. phenylephrine in preventing
propofol-induced hypotension during induction of general
anaesthesia.
Materials and Methods: This randomised clinical trial was
conducted from October 2024-December 2025 at Department
of Anaesthesiology, Shri BM Patil Medical College, Hospital
and Research Centre, BLDE DU, Vijayapura, Karnataka, India.
The study included 130 American Society of Anaesthesiologists
(ASA) I–II patients (18–65 years) undergoing elective general
anaesthesia and were randomised (1:1) to receive i.v.
phenylephrine 100 µg or saline before propofol induction.
Primary outcome was hypotension (≥20% MAP fall). Secondary
outcomes included Systolic Blood Pressure (SBP), Diastolic
Blood Pressure (DBP), MAP, and Heart Rate (HR) at 5, 10, and
15 minutes. Analysed using Statistical Package for the Social
Sciences (SPSS) version 20.0, normally distributed continuous
variables (Shapiro-Wilk test) were expressed as mean±SD and
evaluated via independent student’s t-tests.
Results: The control group’s average age was 37.76±15.69
years (50.8% female, 49.2% male), the study group averaged
34.38±14.30 years (49.2% female, 50.8% male). Postinduction
hypotension was lower in the study group (32.3%, n=21 vs
73.8%, n=48; p-value <0.001). At 5, 10, and 15 minutes, Group
A maintained higher MAP, SBP, and DBP than Group B (all
p-value <0.001), Group A vs Group B MAP was 87.88±8.694
vs 79.45±9.384 (p-value <0.001), 86.51±9.045 vs 74.86±9.890
(p-value <0.001), and 87.60±9.375 vs 77.55±8.816 mmHg
(p-value <0.001); SBP was 117.80±10.145 vs 107.48±11.172
(p-value <0.001), 116.46±10.827 vs 102.37±11.870 (p-value
<0.001), and 117.43±11.243 vs 105.25±10.070 mmHg (p-value
<0.001); DBP was 71.45±9.038 vs 65.18±9.084 (p-value <0.001),
70.20±9.00 vs 60.98±8.977 (p-value <0.001), and 71.32±9.059
vs 63.45±8.646 mmHg (p-value <0.001). Group A HR was
lower at 10 minutes (88.60±11.900 vs 93.29±14.021 bpm,
p-value=0.009) and 15 minutes (85.18±11.144 vs 91.75±12.668
bpm, p-value=0.001).
Conclusion: A single 100 µg bolus of phenylephrine administered
immediately before induction with propofol effectively
attenuated peri-induction hypotension and maintained stable
haemodynamic. This simple intervention improves perioperative
safety in patients at risk of hypotension.
