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

BACKGROUND AND AIMS

Although 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 FEV has been reported as a predictor of sudden cardiac death. This study aimed to determine the association between reduction in FEV following SA and adverse intraoperative cardiopulmonary complications.

MATERIALS AND METHODS

A 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. FEV% predicted was determined using GLI 2012 equations. Participants were grouped into two (∆FEV% < 10% and ∆FEV% ≥ 10%) based on reductions (∆) in FEV% predicted following SA. Logistic regression analyses were used to examine associations between ∆FEV% and intraoperative hypoxia, hypotension, bradycardia, and nausea/vomiting, with adjustments for age, gender, and BMI.

RESULTS

The mean FEV% predicted following SA was lower than the mean FEV% predicted before SA (83.42 vs. 95.31,  = 0.001). In a fully adjusted model, ∆FEV% ≥ 10% was associated with an increased risk of hypoxia [AOR 13.55; 95% CI, 1.07-171.24,  = 0.044]. The positive associations between ∆FEV% ≥ 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.

CONCLUSION

Reduction in FEV% predicted following SA was associated with adverse intraoperative outcomes. FEV may play an important role in the association between SA and cardiopulmonary complications.