How Do Circadian Rhythms Impact Spinal Anesthesia Effects and Surgical Stress Parameters?

Abstract: Understanding how the time of day affects the pharmacokinetics and pharmacodynamics of anesthetic agents is essential for interpreting drug responses and variations in recovery from anesthesia. This study aimed to evaluate differences in the duration of spinal anesthesia and postoperative pain levels after cesarean delivery, focusing on the timing of anesthesia administration. Ninety women undergoing cesarean sections were divided into three groups based on the timing of intrathecal drug administration: group A (08:00-16:00), group B (16:00-00:00), and group C (00:00-08:00). Post-anesthetic evaluations assessed sensory and motor blockade and pain intensity at ten-minute intervals. Blood samples were collected before anesthesia and at 2, 4, 24, and 48 hours post-surgery to measure cortisol and C-reactive protein (CRP) levels. Results showed that group A patients experienced longer durations of motor and sensory blockade, delayed requests for postoperative analgesia, and lower pain scores (all p< 0.05). Significant differences in CRP levels were noted between group A and group B at 24 and 48 hours (p< 0.05).