Interscalene brachial plexus anesthesia with ropivacaine 5 mg/mL and bupivacaine 5 mg/mL: Effects on electrocardiogram
ABSTRACT Cardiotoxicity is the most severe complication of long-acting local anesthetics. The aim of this trial is to compare early signs of depression of cardiac conduction linked with the administration of either ropivacaine or bupivacaine for interscalene block.
Thirty-two patients (American Society of Anesthesiologists I/II) scheduled for elective shoulder arthroscopy were prospectively enrolled to receive, in a randomized and double-blind fashion, either 40 mL of ropivacaine 5 mg/mL or 40 mL of bupivacaine 5 mg/mL for interscalene block. Holter monitoring was started the night before surgery and continued until the end of the study. Peripheral blood sampling was performed before administration of local anesthetics (= baseline) and 15, 20, 25, 30, 35, 40, 45, 60, and 360 minutes after completion of the interscalene block for measurement of total and unbound concentration of the 2 local anesthetics. Alpha-1-acid-glycoprotein was measured at baseline, t(30), and t(360).
All anesthetic blocks in both groups were successful and comparable. Electrocardiographic recordings for QRS, QT, and QTC intervals did not change and were similar in both groups. In the bupivacaine group, significant prolongation of the PQ interval was noted 15 minutes after drug application and remained significantly prolonged until t(60). Total and unbound plasma local-anesthetic concentrations were comparable between both groups at all times. In both groups, local-anesthetic plasma mean levels reached a peak between 30 and 45 minutes after the bolus application. The highest mean plasma levels were 0.103 (+/-0.05) mg/L for unbound ropivacaine and 0.084 (+/-0.03) mg/L for unbound bupivacaine, which occurred in both groups at t(30).
Electrocardiographic recordings were similar in both groups, except for a significant prolongation of the PQ interval in the bupivacaine group at plasma levels below threshold for cardiotoxicity.
[Show abstract] [Hide abstract]
ABSTRACT: Drug-induced prolongation of cardiac repolarization may trigger malignant ventricular arrhythmias, such as torsade de pointes. The duration of QT interval, QT corrected for heart rate (QTc), JT interval, QT dispersion (QTd), QT variability index, and transmular dispersion of repolarization (TDR) are ECG markers of torsadogenicity. All volatiles, especially isoflurane and desflurane, have been found to prolong QTc and QTcd, while sevoflurane has probably no effects on TDR. Among i.v. anaesthetics, propofol seems superior due to its minimal effects on QTc and TDR; moreover, a decrease in QTc and QTcd has been demonstrated in many studies. Regarding opioids, fentanyl, alfentanil, and remifentanil produce no effects on QTc, while sufentanil, at high doses, may induce QT prolongation. Succinylcholine, but not the non-depolarizing neuromuscular blockers, produces QTc prolongation which can be attenuated by opioids and β-blockers. Reversal of neuromuscular block with anticholinesterase-anticholinergic combinations has been associated with significant QTc prolongation, while such an effect has not been demonstrated for sugammadex, even at high doses. Local anaesthetics have probably no intrinsic action on duration of repolarization; nevertheless, an extensive subarachnoid sympathetic block may increase the duration of QTc. On the contrary, thoracic epidural anaesthesia has been associated with a decrease in both QTc and TDR. Among adjuvants, midazolam seems to have no effect on QTc and TDR, while commonly used antiemetics, such as droperidol, domperidone, and most 5-HT3 antagonists, produce significant QT prolongation. The effects of anaesthetic drugs and techniques on electrocardiographic torsadogenic markers should be considered in the perioperative management of patients with preexisting repolarization abnormalities.BJA British Journal of Anaesthesia 12/2013; 112(2). DOI:10.1093/bja/aet412 · 4.35 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Progress made on local anesthetics controlled release formulation and their ability to induce motor and sensory block for a longer period of time brings significant advantages in clinical practice. The use of sustained release formulations provides analgesia for a long period of time with one administration, thus limiting the complications that can occur with conventional analgesia. Also, controlled release of a biologically active compound prevents overdosing,minimizing the side effects, especially cardiotoxicity, neurotoxicity and tissue lesions. Clinical use of liposomal formulation brings high impressive results in pain control and quick patient recovery. Increased patient comfort, reducing to half the hospital length of stay, and treatment costs and are able to provide a higher level of healthcare.01/2015; 31(1):89-95. DOI:10.1016/j.egja.2014.12.004
Article: DOSIS MÁXIMAS DE ANESTÉSICOS LOCALES[Show abstract] [Hide abstract]
ABSTRACT: INTRODUCCIÓN Alguien alguna vez me dijo: «La anestesia es el arte de usar una combinación de venenos en pequeñas dosis, suficientes para ejercer efecto deseado, pero no para matar al pacien-te». Esto es especialmente aplicable a los anes-tésicos locales: Su utilidad en la práctica clínica es indiscutible, pero hay un delicado equilibrio entre administrar una dosis suficiente para ob-tener el efecto deseado (bloqueo de conducción nerviosa), y evitar sus complicaciones (toxici-dad sistémica) 1 . DOSIS MÁXIMAS RECOMENDADAS: FUNDAMENTOS DE SU EXISTENCIA El tema de la validez de las dosis máximas recomendadas no es nuevo, ha estado en discu-sión desde hace más de 30 años. Por una parte, las recomendaciones existentes; por otra, voces «disidentes» que alertan sobre la falta de funda-mento de estas dosis 2,3 . La Tabla 1 muestra un ejemplo de las dosis máximas recomendadas en distintos países. Estas dosis, definidas por las compañías farmacéuticas en su mayoría, son usualmente determinadas a partir de: – datos obtenidos en estudios en animales, – investigación clínica en voluntarios, – datos extrapolados desde pequeñas series clínicas, – información extraída de casos de toxicidad sistémica en pacientes.