Comparison of different concentration of ropivacaine in spinal anesthesia for vascular surgery

Background and Goal of Study: Plain ropivacaine 0,5% vial has been recentely introduced and recommended for intrathecal use. The aim of this randomized study was to compare clinical efficacy and safety of 15 mg plain ropivacaine in different concentration given intrathecally in patients scheduled for vascular surgery (saphenectomies, femoro‐popliteal by‐pass and peripheral aneurysms).Materials and Methods: 38 ASA III patients (mean age 65.5±8.0 years) were scheduled after obtaining written informed consent. All patients had a history of arterial hypertension and other cardiovascular disorders pharmacologically treated. They were divided into two groups A(19 patients) and B (19 patients) receiving respectively ropivacaine 0,75 % 15 mg in a bolus of 2 ml and ropivacaine 0,5 % 15 mg in a bolus of 3 ml. Profile of spinal block (onset and recovery times) and quality of anesthesia (Bromage 0–3 score and pinprick test) were recorded (1). Pulse rate (HR), mean arterial pressure (MAP), cardiac output (CO), left ventricular contractility (dP/dt), systemic vascular resistance (SVR) and global end‐diastolic volume (GEDV) were monitored by the PiCCO System Pulsion in order to evaluate their variations (2). ANOVA test was applied for statistical analysis.Results and Discussion: The median times to onset of complete regression of sensory (140 vs 240 sec; p<0.001) and motor block (175 vs 320 sec; p<0.001) were longer in group B. The quality of sensory and motor block was superior in the group A. The prinpick test at S2 level was similar in both groups. The Bromage scale showed a profile of 2–3 score in group A compared to 1–2 score in group B. 5 patients of group B received additional anesthesia with continuous infusion of propofol 3mg/kg/h because of the poor efficacy of the spinal block. Cardiovascular parameters were not influenced in both groups.Conclusion(s): Spinal anesthesia produced with 15 mg plain ropivacaine 0,75% in a volume of 2 ml is effective and safe in ASA III patients. The concentration of 0,75% gives a complete spinal block in high risk patients without side effects and cardiovascular modifications. A concentration of 0,5% fails to determine an adequate anesthesia level required for vascular surgery and did not offer any advantage in terms of comfort, safety and rapid recovery. Back to Top | Article Outline References: 1 Camorcia M, Capogna G, Lyons G et al. Anesth and Analg 2004; 98: 1779-84. Cited Here... 2 Buhre W, Weyland A, Kazmaier S et al. J Cardiothorac Vasc Anesth 1999; 13: 437-440. Cited Here... | PubMed | CrossRef