Effects of combined arginine vasopressin and levosimendan on organ function in ovine septic shock.

OBJECTIVE: To compare the effects of a first-line therapy of combined arginine vasopressin, levosimendan, and norepinephrine with arginine vasopressin + norepinephrine or norepinephrine alone in ovine septic shock. DESIGN: Prospective, randomized, controlled laboratory experiment. SETTING: University animal research facility. SUBJECTS: Twenty-one chronically instrumented sheep. INTERVENTIONS: After the onset of fecal peritonitis-induced septic shock (mean arterial pressure <60 mm Hg), sheep were randomly assigned to receive first-line treatment with arginine vasopressin (0.5 mU·kg·min), combined arginine vasopressin (0.5 mU·kg·min) and levosimendan (0.2 µg·kg·min), or normal saline (each n = 7) for 24 hrs. In all groups, open-label norepinephrine was additionally titrated to maintain mean arterial pressure at 70 ± 5 mm Hg, if necessary. MEASUREMENTS AND MAIN RESULTS: Arginine vasopressin + levosimendan + norepinephrine improved left ventricular contractility (higher stroke work indices at similar or lower preload) and pulmonary function (Pao2/Fio2 ratio) when compared with the other groups (p < .05 each). Both nonadrenergic treatment strategies reduced open-label norepinephrine doses. However, only arginine vasopressin + levosimendan + norepinephrine limited fluid requirements and positive fluid balance vs. both other groups (p < .05 each). In addition, arginine vasopressin + levosimendan + norepinephrine increased mixed venous oxygen saturation as compared with arginine vasopressin + norepinephrine. Histologic tissue analyses and pulmonary hemeoxygenase-1 activity revealed no differences among groups. Notably, arginine vasopressin + levosimendan + norepinephrine therapy reduced pulmonary 3-nitrotyrosine levels (p = .028 vs. control animals) as well as urinary protein/creatinine ratio (p < .05 each) and slightly prolonged survival when compared with both other groups (4 hrs vs. arginine vasopressin + norepinephrine: p = .013; 7 hrs vs. norepinephrine alone: p = .003). CONCLUSIONS: First-line cardiovascular support with combined arginine vasopressin and levosimendan supplemented with norepinephrine improves myocardial, vascular, pulmonary, and renal function as compared with arginine vasopressin + norepinephrine in septic shock.

Sequence of reperfusion influences ischemia/reperfusion injury and primary graft function following porcine liver transplantation.

The impact of 3 different reperfusion sequences following orthotopic liver transplantation (OLT) in pigs were evaluated. The reperfusion technique commonly performed is primary portal in order to shorten warm ischemic times (WITs). Experimental and clinical data, usually comparing 2 out of 3 possible reperfusion sequences, provide controversial results. OLT was performed in 24 pigs randomized into 3 groups: primary arterial (A), simultaneous (SIM), and primary portal (P) reperfusion. Hemodynamics were continuously monitored and reperfusion injury and primary graft function were assessed by standard serum parameters, histopathological findings, immunohistochemistry for heme oxygenase 1 (HO-1), and heat shock protein 70 (HSP 70). Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and gamma-glutamyl transpeptidase (gammaGT) following reperfusion were significantly increased for group A when compared to groups SIM and P. Hemodynamics showed significant differences after reperfusion compared to physiological data; differences in group comparisons were not significant. The bile production/100 g liver/hr was significantly higher for group SIM (1.15 mL) compared to group P (0.66 mL) and group A (0.62 mL). Histology and immunohistochemistry significantly correlated with functional results and outcome. Histological score was best for group SIM and worst for group A. HSP 70, being visualized mainly in the hepatocytes, showed higher expression for groups SIM and P. Inversely, HO-1, found in perisinusoidal cells, showed highest expression after primary arterial reperfusion. In conclusion, although associated with a 10-minute longer warm ischemic time, simultaneous reperfusion causes the least reperfusion injury with superior primary transplant function. Primary arterial reperfusion showed the worst overall outcome and highest degree of HO-1 expression.