The effect of scoliosis surgery on lung function in the immediate postoperative period

Study Design. Prospective, single-cohort study. Objectives. To determine the immediate change in pulmonary function test (PFT) in children following scoliosis surgery. Summary of Background Data. The number of pediatric scoliosis surgeries is increasing each year because of recent advances in spinal instrumentation, surgical techniques, and improved perioperative monitoring. Pulmonary function decreases immediately following scoliosis surgery, but the extent of this decrease is not well documented in pediatric patients. To use preoperative PFTs to assess the risk of postoperative complications, knowledge of the postoperative decline in PFT is necessary. Methods. We measured preoperative and daily postoperative PFT in 24 children who had scoliosis surgery (age 12.7 +/- 2.7 [SD] years) from January 2002 to June 2003. There were 10 male and 14 female patients. Two (8%) patients had congenital scoliosis, 11 (46%) had idiopathic scoliosis, 9 (38%) had scoliosis due to a neuromuscular disease, and 2 (8%) had kyphoscoliosis. Fifteen (62%) patients had posterior spinal fusion (PSF), 5 (21%) had anterior spinal fusion (ASF), and 4 (17%) had both ASF and PSF performed. PFT parameters (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC, and forced expiratory rate between 25% and 75% of FVC [FEF25%-75%]) were measured before surgery and daily after surgery by bedside spirometry until hospital discharge. Results. PFT declined up to 60% after surgery. The PFT nadir is at 3 days. PFT values remained significantly decreased at 1 week, with values at about half of preoperative baseline. No patient required postoperative mechanical ventilation >= 3 days. There was no statistical significance between the degree of decline in PFT with etiology of either the scoliosis or the type of surgery performed. Conclusions. Our study found that patients are still at risk for postoperative complications as long as 1 week postoperatively and that PFTs do not return to near baseline until 1 to 2 months after surgery. The postoperative decrease in PFT should be considered during preoperative prediction of postoperative risk.