Reduction in FEV1 following spinal anesthesia is associated with intraoperative complications: A prospective study

AbstractBackground and AimsAlthough Spinal Anesthesia (SA) remains the technique of choice for many surgeries below the umbilicus, it is associated with multiple intraoperative complications. Sympathetic blockade and Bezold‐Jarisch reflex do not fully explain SA‐related cardiopulmonary complications. Reduction in FEV1 has been reported as a predictor of sudden cardiac death. This study aimed to determine the association between reduction in FEV1 following SA and adverse intraoperative cardiopulmonary complications.Materials and MethodsA prospective study of 48 patients of ASA status I and II with no history of primary cardiopulmonary disease scheduled for elective surgery under SA. Spirometry was performed based on ATS/ERS guidelines before induction and 30 min after induction of SA. FEV1% predicted was determined using GLI 2012 equations. Participants were grouped into two (∆FEV1% < 10% and ∆FEV1% ≥ 10%) based on reductions (∆) in FEV1% predicted following SA. Logistic regression analyses were used to examine associations between ∆FEV1% and intraoperative hypoxia, hypotension, bradycardia, and nausea/vomiting, with adjustments for age, gender, and BMI.ResultsThe mean FEV1% predicted following SA was lower than the mean FEV1% predicted before SA (83.42 vs. 95.31, p = 0.001). In a fully adjusted model, ∆FEV1% ≥ 10% was associated with an increased risk of hypoxia [AOR 13.55; 95% CI, 1.07–171.24, p = 0.044]. The positive associations between ∆FEV1% ≥ 10% and hypotension [2.02 (0.33–12.46), 0.449], bradycardia [1.10 (0.28–4.25), 0.895] and nausea/vomiting [9.74 (0.52–183.94), 0.129] were not statistically significant.ConclusionReduction in FEV1% predicted following SA was associated with adverse intraoperative outcomes. FEV1 may play an important role in the association between SA and cardiopulmonary complications.