Effect of intravenous paracetamol for post-operative pain relief after tonsillectomy - A study of 70 cases

Abstract

INTRODUCTION: Tonsillectomy is one of the commonest surgical procedures performed in the field of otorhinolaryngology. The most common and distressing symptoms, which follow anaesthesia and surgery, are pain and emesis. The provision of adequate analgesia after tonsillectomy presents the anaesthesiologist with difficulties, as this is a painful procedure and may be associated with significant bleeding into the airway. As evidence continues to accumulate concerning the role of central sensitisation in post operative pain, many researchers have followed methods to prevent central neuropathic changes from occurring, through the utilization of pre-emptive analgesic techniques. Effective preventive analgesic technique may not only be useful in reducing the acute pain, but also chronic post surgical pain and disabilities. Paracetamol is an effective analgesic and an antipyretic agent. The efficiency and tolerability for intravenous Paracetamol are well established. It has a favourable safety profile and it is the most commonly prescribed drug for the treatment of mild to moderate pain. The objective of the present study is to evaluate the post operative analgesia, the haemodynamic profile and the side effects of IV Paracetamol. AIM OF THE STUDY: 1. To evaluate the efficacy of Intravenous Paracetamol as a pre-emptive analgesic in relieving the post operative pain. 2. To study the hemodynamic variables during the post-operative period. 3. To establish the safety of Intravenous paracetamol in patients. MATERIALS AND METHODS: Study Design: Prospective, randomized, double blinded, comparative study. Double blinding was done by taking appropriate dose of intravenous paracetamol calculated in mg/kg and was added to a solution of normal saline to make a volume of 100 ml. This was labelled as drug A. Plain 100 ml of normal saline was labelled as drug B. Neither the person administering the drug nor the person observing the patient in the post operative period did not know the drug. Study Population: After obtaining the institutional ethical committee approval and written informed consent from the parent/guardian, 70 ASA I physical status patients undergoing tonsillectomy were selected between the age group of 6-16 years and weighing between 10-30 kg. Sample Size: 35 patients in the paracetamol group (P group) and 35 in the control group (N group). Probability sampling: All the70 patients were randomised in two groups and the entire patients stood an equal chance of getting into any group. Data collection: 1. Age, Sex, Weight, 2. Pre operative and intra operative pulse rate and blood pressure, Spo2, 3. Duration of surgery, 4. Sedation score using Ramsays Sedation Scale, 5. Visual analogue pain scale at the end of surgery, 1h 2h, 3h, 4h, 5h, 6h. 6. Post operative complications such as: • Drug intolerance, • Nausea and vomiting, • Epigastric pain, • Bleeding, Exclusion Criteria: 1. Upper and lower respiratory tract infections, 2. Cardiac valvular abnormalities, 3. Abnormal bleeding and clotting time, 4. Obstructive sleep apnea, 5. Known history of allergy to paracetamol, 6. Past history of jaundice, 7. Patients on aspirin, 8. Any other concurrent antipyretic, analgesic or anti inflammatory Medications. OBSERVATION AND RESULTS: Data were analysed using SPSS version 13.0 computer software at level of significance p = 0.05. Numerical variables were presented as mean and standard deviation (SD) and categorical variables were presented as frequency (%). Unpaired Student ‘t’ test was used for between-group comparisons between categorical variables. Time to first analgesic administration was analysed by the Kaplan–Meier survival analysis. SUMMARY: 1. Intravenous Paracetamol achieved significant post operative pain relief up to 6 hours. 2. Intravenous Paracetamol delayed the requirement of first dose of rescue analgesic for a mean duration of 6 hours in the post-operative period. 3. Intravenous Paracetamol had a better haemodynamic profile in the post-operative period. 4. Intraveous Paracetamol had a smooth and better post-operative recovery profile rendering a calm, co-operative and tranquil patient. 5. Intravenous Paracetamol did not exhibit any adverse effects in the patients. CONCLUSION: 1. Intravenous Paracetamol can be used as an effective analgesic for providing pre-emptive analgesia. 2. Intravenous Paracetamol provides excellent post operative pain relief. 3. Intraveous Paracetamol has a better hemodynamic profile. 4. Intraveous Paracetamol is safe for use in patients.