Postoperative pain course after paediatric tonsillectomy: A prospective observational study comparing one behavioural and one numerical pain assessment tool

Introduction: Paediatric tonsillectomy is often performed as outpatient surgery, although postoperative pain may be severe and protracted. This prospective observational study evaluated two paediatric pain assessment tools for use in telephone interviews with parents. Methods: ASA I-II children, >= 1 and < 13 years, undergoing outpatient tonsillectomy were recruited. Anaesthesia (propofol-remifentanil) and intraoperative analgesia were standardized. Sedating premedication was not given. Before discharge, a smiley face numerical pain assessment tool was introduced to parents. In telephone interviews on postoperative days 1, 3, 7 and 14, parents scored their childrens pain numerically (0-10) and on the behavioural Postoperative Pain Measure for Parents (PPMP, 0-15). Number of analgesic doses (paracetamol/ibuprofen) per 24 h was noted. Values are median (quartiles). Results: 22 consecutive children were included, age 4 (3-6) years. Parents had administered analgesics to 100%, 95%, 80%, and 5% of children at the four interview times. Numerical pain scores were 3.5 (1-7) at hospital discharge, and 5.5 (3-7), 3 (2-6), 3.5 (0-6), and 0 (0-0) on postoperative days 1, 3, 7, and 14, respectively. In 12/22 children, pain declined to a value of 1 (0-2) on day 7. In 6/22 children pain initially declined, but surged to 5.5 (4-7) on day 7. Significant, protracted pain (9 (6-10) on day 7) was reported in 3/22 children. Behavioural (PPMP) scores were positively correlated to numerical pain scores (day 3: R-2 = 0.48, day 7: R-2 = 0.31, day 14: R-2 = 0.85). With increasing age, children systematically had lower behavioural pain scores for the same numerical pain score (0.61 per years age; p < 0.023). Conclusion: In structured telephone interviews, parents effectively pain scored their children after outpatient tonsillectomy. Numerical and behavioural pain scores correlated well, however age-dependent. Pain courses varied considerably, and a majority of children had significant pain. Pain after paediatric tonsillectomy should be assessed and treatment individualised.