Perioperative analgesic effects of intravenous paracetamol: Preemptive versus preventive analgesia in elective cesarean section

BACKGROUND: Cesarean section (CS) is the one of the most common surgical procedure in women. There is preoperative stress effect before the delivery of the baby as (intubation and skin incision). There is acute postoperative pain, which may be progressed to chronic pain. All these perioperative stress effects need for various approach of treatment, which including systemic and neuraxial analgesia. The different analgesia modalities may affect and impair early interaction between mother and infant. Preemptive intravenous (I.V.) paracetamol (before induction) may reduce stress response before the delivery of the baby, intraoperative opioids and postoperative pain. OBJECTIVES: The aim of this study to compare between the administration of I.V. paracetamol as: Preemptive analgesia (preoperative) and preventive analgesia (at the end of surgery) as regards of hemodynamic, pain control, duration of analgesia, cumulative doses of intraoperative opioids and their related side-effects and to compare between two different protocols of postoperative analgesia and their cumulative doses. PATIENTS AND METHODS: Sixty patients undergoing elective CS were randomly enrolled in this study and divided into two groups of 30 patients each. Group I: i.V. paracetamol 1 g (100 ml) was given 30 min before induction of anesthesia. Group II: i.V. paracetamol 1 g (100 ml) was given 30 min before the end of surgery. Heart rate, systolic blood pressure, diastolic blood pressure, and peripheral oxygen saturation were recorded. Postoperative pain was assessed by visual analog score. Postoperative pethidine was given by two different protocols: group I: 0.5 mg/kg was divided into 0.25 mg/kg intramuscular and 0.25 mg/kg I.V. Group II was given pethidine 0.5 mg/kg I.V. Doses of intraoperative fentanyl, postoperative pethidine, duration of paracetamol analgesic time, time to next analgesia, and side-effects of opioid were noted and compared. RESULT: Preemptive group had hemodynamic stability, especially before delivery of the baby P < 0.001. Preventive group had longer duration of paracetamol analgesia and higher intraoperative opioid P < 0.001 and P < 0.01, respectively. Preemptive group had longer time for next analgesia and lower incidences of postoperative side-effects P < 0.001 and P < 0.05. Preemptive group had higher pain scores in immediate postoperative and after 6 h but preventive group had higher pain scores in 4 and 8 h postoperatively P < 0.001 and P < 0.01, respectively. CONCLUSION: Preemptive paracetamol and immediate postoperative opioid analgesia were more effective than preventive paracetamol.