Skin temperature during sympathetic block: A clinical comparison of bupivacaine 0.5% and ropivacaine 0.5% or 0.75%
Department of Medical and Surgical Critical Care, Unit of Anaesthesia and Intensive Care, University of Florence, Italy.Anaesthesia and intensive care (Impact Factor: 1.3). 07/2006; 34(3):334-7.
Measurement of skin temperature can be used as an indicator of sympathetic blockade induced by neuraxial anaesthesia. The aim of the study was to test the skin temperature response to epidural administration of bupivacaine and different concentrations of ropivacaine. Forty-eight ASA class I-II patients undergoing herniorraphy were enrolled into a prospective, randomized, double-blind clinical trial. Patients were randomly allocated to receive epidural anaesthesia with a single dose of 18 ml of bupivacaine 0.5% (n=16); ropivacaine 0.5% (n=16), or ropivacaine 0.75% (n=16). A temperature probe was positioned on the skin of the thigh and skin temperature registered before epidural anaesthesia, every 10 minutes for the first hour after the epidural injection and every hour for the following four hours. Sensory blockade was assessed by pinprick and motor blockade using the Bromage scale. No significant difference was observed in sensory or motor blockade. A skin temperature rise of 1 to 1.8 degrees C compared with basal values was observed in all patients within the first hour. Temperature returned to basal values within four hours in the ropivacaine 0.5% group, within five hours in the ropivacaine 0.75% group, and remained 1 degrees C higher after five hours in the bupivacaine 0.5% group (P<0.01). The duration of sympathetic block is significantly shorter with ropivacaine than with bupivacaine.
Full-textDOI: · Available from: Alessandro Di Filippo, Oct 12, 2014
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ABSTRACT: The safety of epidural anaesthesia in patients at risk for right ventricular pressure overload remains controversial. We compared the haemodynamic effects of vascular and cardiac autonomic nerve block, induced by selective lumbar (LEA) and high thoracic epidural anaesthesia (TEA), respectively, in an animal model subjected to controlled acute right ventricular pressure overload. Eighteen pigs were instrumented with epidural catheters at the thoracic (T) and lumbar (L) level and received separate injections at T2 (1 ml) and L3 (4 ml) with saline (s) or bupivacaine 0.5% (b). Three groups of six animals were studied: (i) a control group (Ls+Ts), (ii) LEA group (Lb+Ts), and (iii) TEA group (Ls+Tb). Haemodynamic measurements including biventricular pressure-volumetry were performed. Right ventricular afterload was then increased by inflating a pulmonary artery (PA) balloon. Measurements were repeated after 30 min of sustained right ventricular afterload increase. LEA decreased systemic vascular resistance (SVR) and did not affect ventricular function. TEA had minor effects on SVR but decreased left ventricular contractility while baseline right ventricular function was not affected. Control and LEA-treated animals responded similarly to a PA balloon occlusion with an increase in right ventricular contractility and heart rate. Animals pretreated with a TEA did not show this positive inotropic response and developed low cardiac output in the presence of right ventricular pressure overload. In contrast to LEA, TEA reduced the haemodynamic tolerance to PA balloon occlusion by inhibiting the right ventricular positive inotropic response to acute pressure overload.BJA British Journal of Anaesthesia 02/2010; 104(2):143-9. DOI:10.1093/bja/aep354 · 4.85 Impact Factor
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ABSTRACT: Postamputation pain (PAP) affects over 60% of major limb amputees. One of the main challenges in treating PAP is the difficulty involved in identifying pain mechanism(s), which pertains to both residual limb pain (RLP) and phantom limb pain (PLP). In this study, sympathetic blocks were performed on 17 major limb amputees refractory to treatment, including 2 placebo-controlled blocks done for bilateral amputations. One hour postinjection, mean RLP scores at rest declined from 5.2 (SD 2.8) to 2.8 (SD 2.6) (P = .0002), and PLP decreased from 5.3 (SD 3.1) to 2.3 (SD 2.1) (P = .0009). By 1 week, mean pain scores for RLP and PLP were 4.3 (SD 2.9) and 4.2 (SD 3.0), respectively. Overall, 8 of 16 (50%) patients experienced ≥50% reduction in RLP 1-hour postinjection, with the beneficial effects being maintained at 1 and 8 weeks in 4 and 1 patient(s), respectively. For PLP, 8 of 15 (53%) patients obtained ≥50% decrease in pain 1-hour postblock, with these numbers decreasing to 2 patients at both 1 and 8 weeks. In the 2 bilateral amputees who received controlled injections, mean PLP and RLP at rest scores went from 4.0 and 3.3 to 4.0 and 2.5 1-hour postblock, respectively, on the placebo side. On the treatment side, mean PLP and RLP scores decreased from 7.5 and 6.5, respectively, to 0. PERSPECTIVE: The results of this study suggest that sympathetic mechanisms play a role in PLP and to a lesser extent, RLP, but that blocks confer long-term benefits in only a small percentage of patients.The journal of pain: official journal of the American Pain Society 04/2011; 12(8):859-67. DOI:10.1016/j.jpain.2011.01.009 · 4.01 Impact Factor
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ABSTRACT: CONTEXT: Thoracic epidural anaesthesia (TEA) is increasingly used in high-risk surgical patients. We recently demonstrated that TEA-mediated cardiac sympathicolysis prevents the native right ventricular positive inotropic response to the induction of acute pulmonary hypertension. OBJECTIVES: In this subsequent study, we induced a selective TEA after acute pulmonary hypertension had been established. We hypothesised that TEA in these circumstances would also exert negative inotropic effects on the right ventricle, not being mediated by possible effects on vasotonus, right ventricular coronary flow dynamics or right ventricular oxygen balance. DESIGN: Randomised placebo-controlled animal study. SETTING: University hospital animal laboratory. INTERVENTIONS: Eighteen pigs were instrumented with an epidural catheter at the thoracic or lumbar level, a right ventricular pressure-volume catheter, transonic flow probes around the pulmonary artery and the right coronary artery, a pressure catheter in the pulmonary artery and a 22-G catheter within a right ventricular free wall coronary vein. Right ventricular pressure overload was induced by constricting the pulmonary artery. After haemodynamic stabilisation, animals were then assigned to receive TEA (n = 6, 1 ml bupivacaine 0.5%), lumbar epidural anaesthesia (LEA) (n = 6, 4 ml bupivacaine 0.5%) or control (n = 6, isotonic saline). The extent of the sympathetic block was assessed by thermography. Final measurements were performed 30 min after the induction of epidural anaesthesia. RESULTS: Pulmonary artery constriction increased pulmonary artery effective elastance and right ventricular contractility in all groups. TEA caused a sympathetic block ranging from C6 to T6, whereas LEA caused a block from T13 to L5. TEA decreased right ventricular contractility (1.5 +/- 0.6 vs. 3.2 +/- 0.9 mW s ml(-1)) and cardiac output (1.8 +/- 0.3 vs. 2.4 +/- 0.3 l min(-1)), although systemic vascular resistance was unaffected. In the LEA group, systemic vascular resistance decreased, but right ventricular contractility remained unchanged. Right ventricular coronary flow, oxygen delivery and consumption were comparable between the groups. CONCLUSION: During acute pulmonary hypertension, selective blockade of cardiac sympathetic nerves by TEA acutely abolished the protective adaptation of right ventricular contractility to right ventricular pressure overload and deteriorated systemic haemodynamics. This effect was attributable solely to the depression of right ventricular contractility and was neither the result of impaired right ventricular coronary flow dynamics nor of systemic vasodilationEuropean Journal of Anaesthesiology 07/2011; 28(7-7). DOI:10.1097/EJA.0b013e328346adf3 · 2.94 Impact Factor