Efficacy of Intravenous Paracetamol for Attenuating Hemodynamic Response to Laryngoscopy

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Efficacy of Intravenous Paracetamol for Attenuating Hemodynamic Response to Laryngoscopy

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Photo by Derek Finch on Unsplash

Photo by Derek Finch on Unsplash

Why is it important?

Background and Aims: Laryngoscopy and endotracheal intubation violate the patients’ airway reflexes and cause intense sympathetic activity. Literature suggests that this deleterious response may be blunted by drugs. Opioids are most commonly used for this purpose. However, there is no consensus regarding the best drug and best route of administration. Therefore, there has been a growing trend to find an effective substitute to lower these side effects as much as possible. Paracetamol is a non-opioid analgesic with COX-2 selective inhibiting property. The main purpose of our study was to evaluate the effect of pre-operative intravenous paracetamol on hemodynamic response to laryngoscopy and endotracheal intubation. Methods: After Institutional Ethical Committee clearance, 160 patients of American Society of Anesthesiologists (ASA) Physical Status I and II were enrolled in the study and divided into two groups. Group A received 1 gm paracetamol infusion (Labelled A1) in 100 ml volume whereas Group B received 0.9% normal saline infusion (B1) in 100 ml volume Intravenously (I.V.) thirty minutes prior to induction over fifteen minutes. Standard general anesthesia techniques were used for both groups. The hemodynamics were recorded at baseline, before induction, after induction, before laryngoscopy, immediately after intubation and thereafter 1, 3, 5, 7 and 10 inutes following intubation. After 10 minutes of intubation, Group A received the infusion labeled A2 (0.9% Normal saline in 100 ml volume) whereas Group B received the infusion labeled B2 (paracetamol 1 gm in 100 ml volume) over 15 minutes. Results: Both groups were similar in terms of age, sex, height, weight, Mallampati scores and American Society of Anesthesiologists (ASA) physical status. After 1 minute of laryngoscopy and intubation, significant increase in the heart rate was seen in both the groups. (p ≤ 0.05) in Group A, the increase in mean heart rate produced by laryngoscopy and intubation was not statistically significant at 3 mins (p ≥ 0.05) and remained insignificant at 5, 7 and 10 minutes after intubation. However, in Group B the increase in mean heart rate produced by laryngoscopy and intubation was significantly high at 3 min (p ≤ 0.0001) and remained significant at 5, 7 and 10 minutes after intubation. There was significant fall in SBP, DBP and MAP (p ≤ 0.05) from baseline after induction, laryngoscopy and after 1 minute of intubation in both Group A and Group B but inter group comparisons at these time points were statistically insignificant (p ≥ 0.05). Conclusion: Administration of paracetamol (1 gram), thirty minutes prior to induction of anesthesia could not totally blunt all the cardiovascular responses to laryngoscopy and intubation, but it did show better control of heart rate after intubation.

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