Predictors of Postoperative Ventilation in Scoliosis Surgery: A Retrospective Analysis

Background: Patients undergoing corrective surgery for scoliosis may require postoperative ventilation for various reasons.

Aim: The aim was to study the correlation of preoperative (pulmonary function test [PFT], etiology, and Cobb's angle) and intraoperative factors (type of surgery, number of spinal segments involved, blood transfusion, and temperature at the end of surgery) on postoperative ventilation following scoliosis surgery.

Settings And Design: patients' medical records of scoliosis surgery at a tertiary care center during 2010-2016 were retrospectively analyzed.

Materials And Methods: We studied retrospectively 108 scoliosis surgeries done in our institute during this period by the same group of anesthetists using standardized anesthesia technique. We analyzed preoperative (etiology, preoperative PFT, and Cobb's angle) and intraoperative factors (type of surgery, number of spinal segments involved, blood transfusion, and temperature) influencing postoperative ventilation.

Statistical Analysis: For all the continuous variables, the results are either given in mean ± standard deviation, and for categorical variables as a percentage. To obtain the association of categorical variables, Chi-square test was applied.

Results: Patients with Cobb's angle above 76° and spinal segment involvement of 11 ± 3 required postoperative ventilation. Forced expiratory volume in 1 s (FEV1%) <38 and forced vital capacity (FVC%) <38.23 of the predicted could not be extubated. Increased blood transfusion and hypothermia were found to affect postoperative ventilation.

Conclusion: Preoperative factors such as etiology of scoliosis, Cobb's angle, spirometric values FEV1% and FVC% of predicted and intraoperative factors like number of spinal segments involved, affect postoperative ventilation following scoliosis surgery. Increased blood transfusion and hypothermia are the preventable factors leading to ventilation.