Post-Operative Pain Assessment in Children after Surgery for Congenital Heart Defects

Introduction: Effective postoperative pain management in children has become a primary clinical goal for paediatric nurses. Aim: Assessment of post-operative pain in children aged 0-16 years after surgery for a congenital heart defect. Parallel aims were evaluation of post-operative analgesic therapy and investigation of the factors that determine the level of post-operative pain. Method: The study population consisted of 30 infants and children (20 boys, 10 girls) undergoing cardiac surgery. The assessment of the pain level was performed at two stages. The first assessment was made during the first hour after post-operative transfer to the intensive care unit (ICU), using the pain scales: CAAS, FLACC and BNSP. The second assessment was made during the first hour after extubation using FLACC, VAS and FACES. Statistical analysis was performed using the Statistical Package for Social Sciences (SPPS) v. 17.0 for Windows. Results: The mean operation time was 3.55 hours and surgery was performed in almost all cases via sternotomy (n=27, 90%). Midasolam was used as the pre-sedation drug in all cases in a dose of 0.5 mg/kg per os. A mean dose of fentanyl of 336 mcg (SD 280.38 mcg) was administered during the operation. Postoperatively, a continuous i.v. infusion of morphine (40 mcg/kg/hr) was given for a mean duration of 0.48 days (SD 0.74 days). Postoperative PRN analgesia was mainly (90%) based on paracetamol (12.5 mg/kg) and mefenamic acid (5 mg/kg) (26.7%) or i.v. morphine (0.05-0.2 mg/ kg) (60%). At the first post-operative assessment, 30% of the participants were estimated to have moderate or severe postoperative pain, and 36.4% during the first hour after extubation. Correlation was demonstrated between the CAAS score and the FLACC score (r=0.118, p=0.05) and the VAS score (r=0.615, p=0.05). Similarly, the FLACC score after extubation was correlated with the VAS score (r=0.720, p=0.001) and the NFCS score (r=-0.720, p=0.001). Multiple regression analysis revealed the most significant determinants of early post-operative pain and pain after extubation to be the duration of extracorporeal circulation (p=0.043, b=0.594, 95% CI=0.02-1.16) and the total duration of i.v. analgesia (p=0.046, b=0.014, 95% CI=0.00-0.029), respectively. Conclusions: During the early postoperative period after cardiac surgery, children were estimated to experience moderate or severe pain. Further research is needed to determine the factors that lead to inadequate pain management in this population.