Effect of Priming on Intubating Conditions Produced By Atracurium - Comparative Study

Abstract Background: The study was done to see how priming affects the intubating conditions caused by Atracurium. Material and methods: Patients were distributed into 3 groups by random. The subjects in each group were 40 patients. Group A- Priming with 0.1mg/kg Atracurium followed by intubation at 90 second after intubating dose of 0.6mg/kg Atracurium. Group B -0.1mg/kg Atracurium i.v. + Intubation at 120 sec after 2nd dose of 0.6mg/kg Atracurium. Group C- Placebo & Normal saline with intubation at 90 sec post single intubating dose (0.7 mg/kg) of Atracurium. Pre-anaesthetic check-up was performed before surgery, which comprised a detailed history, general physical and systemic examination, and airway evaluation, for every patient. All standard investigations and any other special investigations as might have been required for the patient were performed. The demographic profile i.e. age, sex, weight, height and BMI. Pre- anaesthetic examination was conducted with written informed consent of all patients. The statistical analyses were performed with special care to guarantee the robustness and validity of the findings using different R (v4. 4. 0; R Core Team, 2022). Statistical Description Descriptive statistics were used in this study. The mean ± SD and (Min-Max) were used to describe continuous variables and Number (%) was used to report categorical variables. P < 0.05 was considered statistically significant. Means across groups were compared by ANOVA test. The chi-square (χ²) test was used to test the association of categorical variables. The ggplot2 package was used to create a variety visualisations like heat maps, bar charts and violin plots which enabled a full and detailed understanding of the data. Results: There was no significant difference in gender ratio between the two groups; 42 males and 35 females in Group A and 47 males and 35 females in Group B. Group B had more of the female contestants, a quarter of them were females and rest were males, about15 Contestants. In contrast, the same split as Group A held in Group C, 21 males and 19 females. The Vocal cord positions were divided into three categories: Closed, Semi-closed and Open. The results in terms of the group-A (Table 3).Open vocal cords were commonest on Group B (57.5%), compared to Group A (25%) and Group C (30%). This may mean that Group B had probably been in the most optimal conditions for intubation in which open vocal cords is usual predictor of better visualisation of glottis and easier intubation. Furthermore, of the three groups, Group B had the fewest number of those whose vocal cords were half-closed (20%) while Groups A and C presented an equivalent proportion of 40%.The neuromuscular blockade was monitored using TOF monitoring in which Group B has the highest proportion (52.5%) of patients with only 1 twitch, indicating the deepest neuromuscular blockade. Compared with Group A (30%) and Group C (35%). Lowest % of Partial Blockade (1,2,3 Twitches = 75% Strength): Group B has the lowest proportion (22.5%) of patients in this category, suggesting fewer patients had lighter blockade. Comparison: Group A (25%), Group C (30%). Intermediate Blockade (1,2 Twitches = 80% Strength): Group A has the highest proportion (45%), implying more patients in this group had moderate blockade. Group B (25%) shows the lowest in this category, reinforcing its trend toward deeper blockade. Conclusion: Priming is a valuable technique for achieving rapid muscle relaxation, especially when depolarizing agents like succinylcholine are contraindicated. In this study, a priming dose of 0.1 mg/kg atracurium followed by 0.7 mg/kg after 3 minutes (Group B) resulted in superior intubating conditions compared to other groups. Group B demonstrated, optimal vocal cord positioning, deeper neuromuscular blockade (as indicated by TOF), and more stable hemodynamics. These findings suggest that atracurium priming is an effective and safe alternative for intubation, particularly in high-risk patients or settings where hemodynamic stability is essential.