A prospective study on the association between spinal anesthesia and obesity
Purpose: To compare the outcomes of spinal anesthesia in obese and non-obese patients.
Methods: In this study, 199 patients who underwent total knee replacement arthroplasty (TKRA) were categorized into obesity group (n = 61) and non-obesity group (n = 138). Anesthesia was considered successful if a bilateral T12 sensory blockage occurred within the first 15 min of injection of intrathecal drug. Parameters that influence spinal anesthesia were analyzed using logistic regression by means of multiple variables that independently influence the outcome of spinal anesthesia.
Results: It was observed that the independent predictors for successful anesthesia in the patients were dose of bupivacaine (odds ratio at 95 % confidence interval = 2.08; range: 1.61 - 2.67) and obesity status (odds ratio at 95 % confidence interval = 2.83; range: 1.21 - 6.49). The outcome of the multivariate analysis also indicated that the dose of bupivacaine, body mass index (BMI) and obesity were predictors of spinal anesthesia. It was also found that the period of the sensory blockage due to bupivacaine was longer in the obesity group than in the non-obesity group.
Conclusion: Sensory blockage in bupivacaine anesthesia during TKRA is influenced by dose of bupivacaine, obesity and BMI.
Keywords: Spinal anesthesia, Total knee replacement arthroplasty, Bupivacaine, Obesity, Body mass index, Logistic regression