Lack of Analgesic Effect Induced by Ropivacaine Wound Infiltration in Thyroid Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Surgical site infiltration with local anesthetic reduces analgesic requests in various types of surgeries. Because thyroid surgery may induce severe postoperative pain, we tested the hypothesis that ropivacaine surgical site infiltration would significantly decrease postoperative administration of morphine in patients undergoing thyroid surgery. METHODS: We performed a double-blind, placebo-controlled superiority trial to assess the efficacy of surgical site analgesia with ropivacaine (10 mL, 75 mg) performed at the end of thyroid surgery in adult patients. The primary end point was the proportion of patients not requiring IV morphine in the postanesthesia care unit. RESULTS: One hundred sixty-three patients completed the study, 85 in the placebo group and 88 in the ropivacaine group. The proportion of patients requiring morphine administration in the postanesthesia care unit (55% vs 53%, P = 0.80), the dose of IV morphine administered (5.6 ± 6.1 vs 5.5 ± 6.0 mg, P = 0.90), the total dose of opioids administered (expressed as oral morphine equivalent dose: 64 ± 27 vs 69 ± 29 mg, P = 0.20), and the visual analog pain scale over the first 24 hours were not significantly different between groups. The incidence of adverse events (36% vs 39%, P = 0.88), morphine-related adverse events (19% vs 17%, P = 0.84), serious adverse events (0% vs 2%, P = 0.50), and the patient satisfaction scores (9 ± 1 vs 9 ± 1, P = 0.70) was not significantly different between the 2 groups. CONCLUSIONS: Surgical site analgesia with ropivacaine at the end of thyroid surgery is not associated with any significant analgesic benefit.

Hemodynamic and hormonal responses to the sudden interruption of caval flow: insights from a prospective study of hepatic vascular exclusion during major liver resections.

UNLABELLED: Hepatic vascular exclusion (HVE) combines portal triad clamping and occlusion of the inferior vena cava. Although HVE has been performed for major liver resections during the last 2 decades, little is known about the mechanisms that explain its satisfactory hemodynamic tolerance. Consequently, we performed a comprehensive study of both hemodynamic and hormone responses to HVE. Twenty-two patients who underwent liver resection for secondary tumors developed in noncirrhotic livers were prospectively studied. Heart rate, arterial blood pressure, pulmonary artery pressure, mixed venous saturation, cardiac output, and left ventricular dimensions determined by transesophageal echocardiography were monitored in HVE patients. Blood concentrations of arginine vasopressin (AVP), epinephrine, norepinephrine, dopamine, and atrial natriuretic peptide and plasma renin activity (PRA) were measured before clamping; 5, 15, and 30 min after clamping; and 15 min after unclamping. Hemodynamic response to HVE was characterized by a significant (P < 0.05) decrease in left ventricular dimensions, fractional area change, and pulmonary artery pressure. We also observed a marked decrease in cardiac output (50%) and an increase in heart rate and systemic vascular resistance. After unclamping, there was peripheral vasodilation, assessed by a significant decrease in systemic vascular resistance from the preclamping value to unclamping. An acute and sustained increase in AVP and norepinephrine that returned to baseline after unclamping and the absence of modification in PRA concentrations were noted. The marked decrease in venous return that characterizes HVE is compensated for by an increase in vascular resistance secondary to an important activation of the AVP and sympathetic systems. The PRA system does not play an important role in maintaining arterial blood pressure during HVE. IMPLICATIONS: Hemodynamic and hormonal responses to the acute interruption of caval venous return to the heart were investigated in patients undergoing liver resection with hepatic vascular exclusion. A compensatory role for arginine vasopressin and sympathetic systems that provoked increased vascular resistance was demonstrated.