Efficacy of Cis-Atracurium vs Atracurium in Patients undergoing Abdominal Procedures: A Randomised Clinical Study

Abstract

Introduction: Cis-atracurium has a neuromuscular blocking capacity approximately three times that of atracurium besylate. The Effective Dose (ED) 95 of cis-atracurium is 0.04 mg/kg, while that of atracurium is 0.2 mg/kg. Cis-atracurium is preferred over atracurium due to the lack of histamine release, providing better cardiovascular stability. This study compares these two drugs in terms of haemodynamic parameters, neuromuscular blocking properties, intubating conditions, and safety profiles. Aim: To assess the efficacy of atracurium and cis-atracurium from various perspectives, including neuromuscular blockade, haemodynamic stability, and safety profiles. Materials and Methods: A double-blinded, randomised clinical study was conducted from January 2019 to October 2019 in Rajkot, Gujarat, India. Sixty patients undergoing abdominal surgeries under general anaesthesia were allocated to two groups. Group A received a loading dose of atracurium 0.5 mg/kg followed by a maintenance dose of 0.1 mg/kg, while Group B received a loading dose of cis-atracurium 0.2 mg/kg followed by a maintenance dose of 0.03 mg/kg. During the surgical procedure, parameters studied included neuromuscular blockade, hemodynamic changes, intubating conditions, and safety profiles in terms of complications. Student’s t-test was used to analyse normally distributed continuous variables, and the chi-square test was used for qualitative variables. Results: The demographic profiles were comparable in both groups in terms of age (p-value=0.800), sex (p-value=0.393), weight (p-value=0.101), and American Society of Anaesthesiologists (ASA) grading (p-value=0.509). A significant increase in heart rate (99.46±8.06 (/minute) vs. 91.66±9.11 (/minute)) and mean arterial blood pressure (104.44±10.16 (mm of Hg) vs. 93.4±12.77 (mm of Hg)) was noted post-intubation in Group A compared to Group B. Patients in Group A (3.5±0.62 minutes) had a faster onset of neuromuscular blockade compared to Group B (4.6±0.49 (minutes)), while the duration of action of the first loading dose and the 25% recovery time from the last supplemental dose was longer in Group B (52.86±5.18 minutes and 41.66±3.60 minutes) than in Group A (31.2±4.82 minutes and 20.86±4.37 minutes). Fewer patients experienced complications (hypotension, erythema of the skin) in Group A compared to Group B. Conclusion: Cis-atracurium releases less histamine compared to atracurium and has a longer duration of action. Cis-atracurium can be a better alternative to atracurium as it offers better haemodynamic, neuromuscular, and safety profiles with similar intubating conditions.

Keywords

• general anaesthesia
• haemodynamics
• histamine
• intubation
• muscle-relaxant