Passive leg raising can predict fluid responsiveness in patients placed on venovenous extracorporeal membrane oxygenation.

INTRODUCTION: In ICUs, fluid administration is frequently used to treat hypovolaemia. Because volume expansion (VE) can worsen acute respiratory distress syndrome (ARDS) and volume overload must be avoided, predictive indicators of fluid responsiveness are needed. The purpose of this study was to determine whether passive leg raising (PLR) can be used to predict fluid responsiveness in patients with ARDS treated with venovenous extracorporeal membrane oxygenation (ECMO). METHODS: We carried out a prospective study in a university hospital surgical ICU. All patients with ARDS treated with venovenous ECMO and exhibiting clinical and laboratory signs of hypovolaemia were enrolled. We measured PLR-induced changes in stroke volume (ΔPLRSV) and cardiac output (ΔPLRCO) using transthoracic echocardiography. We also assessed PLR-induced changes in ECMO pump flow (ΔPLRPO) and PLR-induced changes in ECMO pulse pressure (ΔPLRPP) as predictors of fluid responsiveness. Responders were defined by an increase in stroke volume (SV) > 15% after VE. RESULTS: Twenty-five measurements were obtained from seventeen patients. In 52% of the measurements (n = 13), SV increased by > 15% after VE (responders). The patients' clinical characteristics appeared to be similar between responders and nonresponders. In the responder group, PLR significantly increased SV, cardiac output and pump flow (P < 0.001). ΔPLRSV values were correlated with VE-induced SV variations (r² = 0.72, P = 0.0001). A 10% increased ΔPLRSV predicted fluid responsiveness with an area under the receiver operating characteristic curve (AUC) of 0.88 ± 0.07 (95% confidence interval (CI95): 0.69 to 0.97; P < 0.0001), 62% sensitivity and 92% specificity. On the basis of AUCs of 0.62 ± 0.11 (CI95: 0.4 to 0.8; P = 0.31) and 0.53 ± 0.12 (CI95: 0.32 to 0.73, P = 0.79), respectively, ΔPLRPP and ΔPLRPO did not predict fluid responsiveness. CONCLUSIONS: In patients treated with venovenous ECMO, a > 10% ΔPLRSV may predict fluid responsiveness. ΔPLRPP and ΔPLRPO cannot predict fluid responsiveness.

Postoperative ketamine administration decreases morphine consumption in major abdominal surgery: a prospective, randomized, double-blind, controlled study.

BACKGROUND: Ketamine decreases postoperative morphine consumption, but its optimal dosing and duration of administration remain unclear. In this study, we compared the effects of ketamine administration on morphine consumption limited to the intraoperative period, or continued for 48 h postoperatively. METHODS: Eighty-one patients scheduled for abdominal surgery were prospectively randomized under double-blind conditions to three groups: (1) PERI group receiving intraoperative and postoperative ketamine for the first 48 h after surgery (2 microg x kg(-1) x min(-1) after a 0.5 mg/kg bolus); (2) INTRA group receiving intraoperative ketamine administration only (2 microg x kg(-1) x min(-1) after a 0.5 mg/kg bolus); and (3) CTRL group receiving placebo. Morphine consumption, visual analog scale scores and side effects (sedation score, nausea-vomiting score, nightmares, psychiatric disorders, or delusions) were recorded for the first 48 h. RESULTS: Cumulative morphine consumption 24 h after surgery was significantly lower in the PERI group (median = 27 mg, interquartile range = [19]) than in the INTRA group (48 mg [41.5]) and CTRL group (50 mg [21]) (P < 0.005). Postoperative visual analog scale scores were significantly lower in the PERI group and INTRA group than in the CTRL group (P < 0.001). A higher rate of nausea was observed in the CTRL group compared with the PERI group (27% vs 4%, P = 0.005). No difference in sedation scores or psychiatric disorders was observed among groups. CONCLUSIONS: Low-dose ketamine improved postoperative analgesia with a significant decrease of morphine consumption when its administration was continued for 48 h postoperatively, with a lower incidence of nausea and with no side effects of ketamine.

Insulin maintains plasma antioxidant capacity at an early phase of kidney transplantation.

BACKGROUND: Ischaemia-reperfusion and hyperglycaemia are two main sources of oxidative stress that plays an important role in the pathophysiology of tissue injury in transplant recipients. We hypothesized that controlling hyperglycaemia with insulin during the first hours following kidney transplantation could improve antioxidant defences and therefore decrease ischaemia-reperfusion-induced injury. METHOD: We performed a prospective randomized study in non-diabetic dialysed patients receiving a first cadaveric renal allograft, and assigned them to receive either 200 g/day of glucose infusion (control group, n=23) or the same glucose infusion and intravenous insulin to maintain blood glucose<10 mmol/l (insulin group, n=20). Antioxidant defences were assessed by the plasma total radical-trapping antioxidant parameter (TRAP). RESULTS: TRAP values remained stable throughout the study in the Insulin group, whereas they decreased from admission to day 1 (-2.70+/-0.16 vs -2.98+/-0.26, P<0.0001), and tended to retrieve the basal values at day 15 in the control group. TRAP values were significantly higher in the insulin group compared with the control group at days 1 (-2.80+/-0.19 vs -2.98+/-0.16, P<0.05) and 4 (-2.80+/-0.19 vs -2.95+/-0.20, P<0.05). No differences were found between the two groups on urinary malondialdehyde determination, two markers of oxidative damage, nor in graft function or patient outcome. CONCLUSIONS: This is the first clinical trial to demonstrate improvement in insulin-induced antioxidant defences at the early stage of kidney transplantation. More extensive studies will tell if this strategy has beneficial impact in long-term graft outcome.