Effects of Continuous versus Single Dose Spinal Anesthesia in Octogenarians Undergoing Hip Surgery: Randomized Control Trial

Abstract

Abstract Background Continuous spinal anesthesia (CSA) is an anesthetic technique that offers several clinical advantages for anesthesia and analgesia in elderly patients. The level of sensory blockade can be titrated to the desired dermatomal level with great precision with intrathecal (IT) catheters, allowing better control of the hemodynamic consequences of sympathetic blockade associated with spinal anesthesia compared to epidural or single shot spinal techniques. Octogenarians are expected to suffer more from hemodynamic instability with spinal anesthesia. Objective The primary outcome is to compare the incidence of hypotension (defined as decrease in mean arterial blood pressure > 20% from the base line) in continuous spinal anesthesia CSA versus single dose spinal anesthesia in octogenarians undergoing hip surgery. The secondary outcome is to determine the total use of vasopressor (Ephedrine) and the incidence of spinal complications as nausea, vomiting and post Dural puncture headache. Methods This is a randomized controlled clinical trial done at Ain-shams University Hospitals, Cairo, Egypt within a period of 6 months from approval of medical ethics committee. Twenty patients in CSA group received increments of (0.5 ml) of plain bupivacaine 0.5% until T10 level blockade is achieved. Twenty patients in SDA group received single shot of (2.5ml) of bupivacaine 0.5%. Results The main finding of this study is that while MAP was significantly lower between 5-35 minutes (<0.001), it was significantly higher between 40-75 minutes in SDA group than CSA group (0.05).Total bupivacaine dose was significantly higher in SDA (12.5±0.8) group than CSA group (7.6±1.3) (p < 0.001). The total ephedrine dose needed was significantly higher in the SDA group (19.5 ±11.3) than in CSA group (4.5±1.7) (p.0.006). Conclusion The main finding of this study is that for octogenarians undergoing hip surgery, while MAP was significantly lower between 5-35 minutes, it was significantly higher between 40-75 minutes in single dose spinal anesthesia group than continuous spinal anesthesia group. Episodes of bradycardia were similar in both groups. The bupivacaine dose as well as total ephedrine dose was significantly higher in SDA group than CSA group. Groups were similar in the incidence of postoperative complications related to the neuraxial blockade. The impact of these changes on the overall cardiovascular status and outcome in octogenarians undergoing hip surgery could not be determined from our study design.