Postoperative Analgesia Following Surgical Correction for Adolescent Idiopathic Scoliosis: A Comparison of Epidural Analgesia and PCA

Purpose: The two most commonly utilized pain management techniques following operative correction of adolescent idiopathic scoliosis (AIS) are continuous epidural analgesia (CEA) and patient controlled analgesia (PCA). However, there are no large published reports directly comparing these two modalities in AIS. The purpose of this study was to compare CEA and PCA with respect to the safety and efficacy following operative correction of AIS in a large series of patients from a single institution.

Methods: A retrospective medical record review was performed from 1990 to 2001 of patients undergoing a primary surgery for AIS from a single institution. Demographic and operative data were recorded. Visual Analog Scale (VAS) scores were recorded postoperatively at multiple time periods. The VAS ranges from 0 (very happy with no pain) to 5 (hurts as much as you can imagine). Adverse effects and complications related to each pain management technique were noted. The students paired t test was used for comparison with a significance level defined as p<0.05.

Results: There were 413 patients in the CEA group and 200 patients in the PCA group. There were no differences between the CEA and PCA groups with respect to age, sex, race, curve type, levels fused (8.4 vs. 8.7), and curve magnitude (57.9 vs. 56.9). The average of all pain scores was significantly better in the CEA group when compared to the PCA group (1.3 vs. 1.9) (P<0.0001). The pain scores at postoperative hours 2, 4, 6, 8, 12, 24, 36, and 48 were significantly less for the CEA group (p<0.001). The range (minimum to maximum) of pain scores was less in the CEA group (2.3 vs 2.7)(p<0.05) and the average maximum score was less in the CEA group (2.6 vs 3.2)(p<0.05). The need to temporarily stop and then restart the pain management was greater in the CEA group than the PCA group (12.4% vs 7.0%) (p=0.04) and most often due to respiratory depression or sedation. Premature permanent discontinuation of pain management was more common in the CEA group than the PCA group (13.1% vs 0.0%) (p<0.001) and was most often due to uncontrollable pain. Adverse effects (nausea, vomiting, pruritus, respiratory depression and transient sensory changes) were significantly more common in the CEA group. There were no permanent neurologic injuries in either group.

Conclusions: Although both CEA and PCA provide effective pain control following surgery for AIS, patients with CEA had significantly better pain scores for all time periods, less fluctuations in pain and lower maximum pain levels during the postoperative period. However, close vigilance is required with patients treated with CEA since adverse effects are common and may required temporary discontinuation to avoid permanent injury.