Hemodynamic Changes Of Continuous Spinal Anesthesia In Elderly Patients Undergoing Hip Joint Surgery

Objective:To compare the anesthesic effects and hemodynamic changes between the continuous spinal anesthesia(CSA) and combined spinal-epidural anesthesia (CSEA) with ropivacaine in elderly patients for hip joint surgery.Methods:Sixty ASA class I-II patients aged65to95years undergoing hip joint operation including replacements of total hip and artificial thigh bone were randomly divided into CSA group and CSEA group. Each group had30patients. On arrival in the operating room, the patients were given oxygen at the rate of two liters/minute through a oxygen mask and received Penehyclidine Hydrochloride0.01mg/kg and Midazolam0.03～0.04mg/kg as premedication. Standard monitoring was implemented:electrocardiography, finger pulse oximetry and non-invasive blood pressure measurement (at five-minute intervals). An intravenous preload of300ml of Hydroxyethyl Starch was given over20～30minutes. All blockades were performed in the L2-L3interspace with the patient awake in the lateral position.An initial subarachnoid bolus of0.75% hyperbaric ropivacaine0.5-1ml was injected in the CSA group, if analgesia did not reach T10, supplemental ropivacaine was injected by titrate incremental doses. The catheter was then fed over the needle into the intrathecal space about1-2centimeters long. In the CSEA group,0.75% hyperbaric ropivacaine1～2ml was injected to the subarachnoid at L2-3, and then a catheter about3～4centimeters long was inserted into the epidual space for anesthesia mainteinance. CO,MAP,SVR,acceleration index(ACI)and thoracic fluid content(TFC)were recorded with noninvasive hemodynamics monitor. The following data were recorded: dosage of local anesthetic,demographic data, time taken for the effect, highest level of sensory blockade and the time taken, quality of motor blockade according to the Bromage scale.Hypotension (defined as a30%decrease in systolic blood pressure, in comparison with preoperative control levels) was treated with ephedrine10～15mg intravenously. Bradycardia (defined as heart rate less than50beats/min) was treated with atropine0.25-0.5mg intravenously. For the first three postoperative days, patients were visited daily. Record the examples which had the adverse reaction such as shake,nausea,vomit,PDPH,TNS and CES et.Results:1. The patient characteristics in the two groups were comparable with regard to age, gender, weight, height and duration of surgery(P>0.05). The time taken for performing the blockade had no significant difference(P>0.05). It took less dosage (1.7ml)in the CSA group when the blockade reached T10while the CSEA group took about2.8ml. The time sensory block to T10was significantly shorter in the CSEA group (5.3min) than in the CSA group (9.6min). The maximal level and motor block were more rapid when the CSEA technique was used. According to the Bromage scale, the motor blockade was similar in the two groups.2.(1) There were no significantly differences of mean arterialpressure(MAP),heatr rate (HR), stroke volume (SV),cardiac output(CO), acceleration cardiac index (ACI), systemic vascular resistance (SVR)in the CSA group after anesthesia.(2)The MAP,HR,SV,CO,ACI,SVR were decreased significantly in the time of5-20min after anesthesia in the CSEA group (P<0.05)(3)There were significantly differences in the maximum decline of the hymodynamic changes in the two groups (P<0.05)(4)There was no significantly difference of thoracic fluid content (TFC)in the two groups (P>0.05)3.Arterial hypotension was found and Ephedrine was needed in5patients in the CSEA group and2patients in the CSA group when the anesthesia started till30 minutes later, and thus it occurred significantly more often in the CSEA group. Bradycardia was observed in five patients from the CSEA group while not found in the CSA group. SpO2had no significant change in both groups.9patiets felt discomfortable when the Spinocath catheter was inserted into the subarachnoid space.4.Postdural puncture headache (PDPH) in two patients from the CSA group,and one from the CSEA group were observed in the three postoperative days. i.e. without significant difference between the groups. There were no cases of cauda equina syndrome, transient radicular symptoms, lumbodynia or other severe complications after surgery in either group.Conclusion:Compared to CSEA, CSA is a safe technique of spinal anesthesia with small anesthetic dosages, more reliable and hemodynamically stable and more controllability in patients for hip joint operation.