IV Paracetamol as a sole agent for postoperative pain relief in adult cardiac surgical patients after median sternotomy

Abstract

Various pain control strategies for pain relief of cardiac surgical patients after median sternotomy were tried include central neuraxial blockade or selective nerve blocks, and drugs such as opioids, and non-steroidal anti-inflammatory drugs (NSAIDS). Paracetamol (Perfalgan, Bristol Meyers Squibb) is available in IV formulation and is being used in many centers as an adjunct to analgesia regimen. In our practice, we have found that IV paracetamol stared at regular intervals after shifting the patient to cardiac surgical ICU(CSICU), helps in significantly reducing the analgesic requirement consequently patients become less sedated after cardiac surgery. After ethics committee approval, and informed patient consent, we did a prospective cohort study of 52 adult cardiac surgical receiving IV paracetamol as the primary pain control agent. A standard anesthesia and analgesia technique was used for all the patients. Postoperatively IV fentanyl infusion was continued at 1 mcg/kg/h till extubation. IV paracetamol was started 30 min before extubation given 1 g (over 30 min) IV and continued 6 h till next 72 h or till chest tube removal. Pain control was assessed by visual analogue scale (VAS) and target VAS value of 3 or less than three was considered adequate. VAS was assessed at extubation, at 3, 6, 12, 24, 36 and 48 h after extubation. The regimen was considered successful if only two or less than two doses of IV fentanyl and/or less than 4 doses of oral tramadol were required to supplement IV paracetamol postoperatively. The patient age ranged from 24 to 78 years, 8 of them were female, CABG was performed in 14 patients, AVR in 8 patients, CABG plus MVR in 6 patients, CABG plus AVR in 10 patients, MVR plus RFA in 6 patients, ASD closure in 4 patients and pulmonary valve implantation in 2 patient. We found that paracetamol was successful as the sole analgesic agent in 38 patients (73%), in 10 patients (19.2%) IV paracetamol was primary regimen (with fentanyl/tramadol as adjunct) and in 4 patients (7.6%) patients IV paracetamol regimen was unsuccessful in pain relief. IV Paracatamol may be used as a sole agent for pain relief with successful results after median sternotomy in selected patients in which opioids, NSAIDS or regional blocks are not indicated or produce undesirable side effects. The results need to be reproduced in a larger group of patients and after determining equipotent doses of opiods, case control studies should be done to evaluate the effects of IV paracetamol after median sternotomy.