Answer to the Letter to the Editor of Hadi Raeisi Shahraki concerning “Predictive factors for respiratory failure and in-hospital mortality after surgery for spinal metastasis” by Jaipanya P, et al. (Eur Spine J [2023]: doi: 10.1007/s00586-023-07638-z)

Purpose Spinal metastasis surgeries carry substantial risk of complications. PRF is among complications that significantly increase mortality rate and length of hospital stay. The risk factor of PRF after spinal metastasis surgery has not been investigated . This study aims to identify the predictors of postoperative respiratory failure (PRF) and in-hospital death after spinal metastasis surgery. Methods We retrospectively reviewed consecutive patients with spinal metastasis surgically treated between 2008 and 2018. PRF was defined as mechanical ventilator dependence > 48 h postoperatively (MVD) or unplanned postoperative intubation (UPI). Collected data include demographics, laboratory data, radiographic and operative data, and postoperative complications. Stepwise logistic regression analysis was used to determine predictors independently associated with PRFs and in-hospital death. Results This study included 236 patients (average age 57 ± 14 years, 126 males). MVD and UPI occurred in 13 (5.5%) patients and 13 (5.5%) patients, respectively. During admission, 14 (5.9%) patients had died postoperatively. Multivariate logistic regression analysis revealed significant predictors of MVD included intraoperative blood loss > 2000 mL (odds ratio [OR] 12.28, 95% confidence interval [CI] 2.88–52.36), surgery involving cervical spine (OR 9.58, 95% CI 1.94–47.25), and ASA classification ≥ 4 (OR 6.59, 95% CI 1.85–23.42). The predictive factors of UPI included postoperative sepsis (OR 20.48, 95% CI 3.47–120.86), central nervous system (CNS) metastasis (OR 10.21, 95% CI 1.42–73.18), lung metastasis (OR 7.18, 95% CI 1.09–47.4), and postoperative pulmonary complications (OR 6.85, 95% CI 1.44–32.52). The predictive factors of in-hospital death included postoperative sepsis (OR 13.15, 95% CI 2.92–59.26), CNS metastasis (OR 10.55, 95% CI 1.54–72.05), and postoperative pulmonary complications (OR 9.87, 95% CI 2.35–41.45). Conclusion PRFs and in-hospital death are not uncommon after spinal metastasis surgery. Predictive factors for PRFs included preoperative comorbidities, intraoperative massive blood loss, and postoperative complications. Identification of risk factors may help guide therapeutic decision-making and patient counseling.