Vasodilatation médiée par sympathectomie: une étude randomisée de détermination de la concentration de bupivacaïne péridurale

Abstract

Purpose We tested the hypothesis that the development of sympathectomy-mediated vasodilatation is dependent on the concentration rather than the dose of epidural local anesthetic administered. Methods Sixty subjects receiving lumbar epidural bupivacaine were randomised to one of three groups: A: 10 ml 0.5% (50 mg); B: 10 ml 0.25% (25 mg); and C: 40 ml 0.0625% (25 mg). Groups A and B had equal volume but a twofold difference in drug dose, while groups B and C had equal drug dose, but a fourfold difference in drug volume. At baseline and 5, 10, and 20 min following epidural bupivacaine administration, we assessed the following indices of sympathectomy: pulse oximeter perfusion index in the toe and finger, skin temperature in the toe and finger, and mean arterial pressure. We also assessed sensory level (pinprick, cold, and light touch) and motor block. Results There was an increase in the pulse oximeter perfusion index by 20 min of 280%, 303%, and 59% in groups A, B, and, C, respectively. There was a significant sympathectomy-mediated vasodilatation in the toe for both groups A (P = 0.002) and B (P \ 0.001) but not C (P = 0.22). Vasoconstriction in the finger was observed in group A only (P = 0.015) but not in group B (P = 0.09) or group C (P = 0.20). There were similar blood pressure changes and similar sensory changes in all groups. The intensity of motor block increased with increasing drug concentration. Conclusions Our observations suggest that drug concentration is more important than drug dose in determining the degree of sympathectomy following lumbar epidural local anesthesia. RésuméObjectif Nous avons teste´l'hypothe`se selon laquelle l'apparition d'une vasodilatation me´die´e par sympathectomie e´tait lie´e à la concentration plutôt qu'a`la dose d'anesthe´sique local pe´ridural administre´. Méthode Soixante patients recevant de la bupivacaı¨ne pe´ridurale lombaire ont e´te´randomise´s en trois groupes : A : 10 ml 0,5 % (50 mg); B : 10 ml 0,25 % (25 mg); et C : 40 ml 0,0625 % (25 mg). Les groupes A et B ont reçu un volume e´quivalent mais la dose de me´dicament e´tait double´e pour le groupe A, alors que les groupes B et C ont reçu une dose e´gale, mais le volume de me´dicament a e´teq uadruple´pour le groupe C. Nous avons e´value´les indices de sympathectomie suivants aux niveaux de base ainsi qu'a5 , 10 et 20 minutes apre`s l'administration de la bupivacaı¨ne pe´ridurale : indice de perfusion de l'oxyme`tre de pouls a`l'orteil et au doigt, tempe´rature cutane´e à l'orteil et au doigt, et tension arte´rielle moyenne. Nous avons e´galement e´value´le niveau sensoriel (piquˆre a`l'aiguille, froid et toucher le´ger) et le bloc moteur. Résultats Sur la base de l'indice de perfusion de l'oxyme`tre de pouls, nous avons observe´une vasodilatation 123Can J Anesth/J Can Anesth (2009) 56:213-221 DOI 10.1007 me´die´e par sympathectomie significative dans l'orteil pour les groupes A (P = 0,002) et B (P \ 0,001) mais pas dans le groupe C (P = 0,22). La vasoconstriction au doigt a e´teó bserve´e uniquement ...

The Effect of Regional Analgesia on Vascular Tone in Hip Arthroplasty Patients

“…Decrease in sympathetic outflow (through concomitant blockade of ganglia and nerves of the autonomic nervous system) is a well-studied effect of regional anesthetic techniques. This partial sympathectomy and subsequent vasodilatation was observed in spinal and epidural analgesia as well as after performance of peripheral nerve blocks; yet, whether there is an influence of different local anesthetic agents and concentrations is not fully understood [5,8,22]. Interestingly, AI reached its peak in the operating room, shortly before the procedure started, and it kept decreasing steadily until the last day of sampling on postoperative day two (POD-2), even after the neuraxial analgesia and the peripheral nerve block (in the intervention group) had worn off.…”

“…Human/Animal Rights: All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008 (5).…”

Perfusion index and plethysmographic variability index in patients with interscalene nerve catheters

“…In previous studies, vasodilatation caused by epidural anesthesia increased the pulse oximeter PI. 3,11 Therefore, the PI could be a valuable indicator for correct placement of interscalene nerve block. An increase in the difference in PI between both arms (PI blocked arm -PI contralateral arm) was seen in 80% of patients with successful blocks, which can be considered acceptable.…”

Assessment of skin temperature during regional anaesthesia—What the anaesthesiologist should know

“…Contradictory results have been published regarding skin temperature in the thoracic and abdominal region in patients receiving thoracic epidural anaesthesia. Either no change in skin temperature at the thorax, abdomen or thigh was found, or a decrease was observed . However, all changes described were usually below 1°C, which is most likely explained by the already relatively warm trunk and the little variation in skin blood flow in comparison to the extremities.…”