Inotropes in goal-directed therapy: Do we need 'goals'?

There is substantial evidence to demonstrate the benefits of goal-directed hemodynamic optimization using fluid loading or inotropic support or both to improve outcome during major surgery. However, until now, only limited pathophysiological data have been available to explain this benefit. The maintenance of adequate tissue perfusion and global oxygen delivery is an essential goal for therapy. In an interesting study, Jhanji and colleagues provided additional data that emphasize the roles of optimization of intravascular fluid status and low doses of inotropes to improve microvascular blood flow and tissue oxygenation. This commentary aims to highlight some issues raised by this important study and provides additional elements to further position these results

Central venous O2 saturation and venous-to-arterial CO2 difference as complementary tools for goal-directed therapy during high-risk surgery

International audienceIntroduction: Central venous oxygen saturation (ScvO 2) is a useful therapeutic target in septic shock and high-risk surgery. We tested the hypothesis that central venous-to-arterial carbon dioxide difference (P(cv-a)CO 2), a global index of tissue perfusion, could be used as a complementary tool to ScvO 2 for goal-directed fluid therapy (GDT) to identify persistent low flow after optimization of preload has been achieved by fluid loading during high-risk surgery. Methods: This is a secondary analysis of results obtained in a study involving 70 adult patients (ASA I to III), undergoing major abdominal surgery, and treated with an individualized goal-directed fluid replacement therapy. All patients were managed to maintain a respiratory variation in peak aortic flow velocity below 13%. Cardiac index (CI), oxygen delivery index (DO 2 i), ScvO 2 , P(cv-a)CO 2 and postoperative complications were recorded blindly for all patients. Results: A total of 34% of patients developed postoperative complications. At baseline, there was no difference in demographic or haemodynamic variables between patients who developed complications and those who did not. In patients with complications, during surgery, both mean ScvO 2 (78 ± 4 versus 81 ± 4%, P = 0.017) and minimal ScvO 2 (minScvO 2) (67 ± 6 versus 72 ± 6%, P = 0.0017) were lower than in patients without complications, despite perfusion of similar volumes of fluids and comparable CI and DO 2 i values. The optimal ScvO 2 cutoff value was 70.6% and minScvO 2 < 70% was independently associated with the development of postoperative complications (OR = 4.2 (95% CI: 1.1 to 14.4), P = 0.025). P(cv-a)CO 2 was larger in patients with complications (7.8 ± 2 versus 5.6 ± 2 mmHg, P < 10-6). In patients with complications and ScvO 2 ≥71%, P(cv-a)CO 2 was also significantly larger (7.7 ± 2 versus 5.5 ± 2 mmHg, P < 10-6) than in patients without complications. The area under the receiver operating characteristic (ROC) curve was 0.785 (95% CI: 0.74 to 0.83) for discrimination of patients with ScvO 2 ≥71% who did and did not develop complications, with 5 mmHg as the most predictive threshold value

The OPERA trial - comparison of early nasal high flow oxygen therapy with standard care for prevention of postoperative hypoxemia after abdominal surgery: study protocol for a multicenter randomized controlled trial

BACKGROUND: Respiratory support following postoperative extubation is of major importance to prevent hypoxemia and subsequent respiratory failure and reintubation. High-flow nasal cannula oxygen (HFNC) delivers a flow-dependent positive airway pressure and improves oxygenation by increasing end-expiratory lung volume. Whether application of HFNC may have therapeutic advantages over conventional oxygen therapy for respiratory support in the early postextubation surgical period remains to be established. METHODS/DESIGN: The Optiflow for prevention of post-extubation hypoxemia after abdominal surgery (OPERA) trial is an investigator-initiated multicenter randomized controlled two-arm trial with assessor-blinded outcome assessment, randomizing 220 patients with intermediate to high risk of pulmonary complications after abdominal surgery to receive HFNC or conventional oxygen therapy following extubation, stratified by the presence of epidural analgesia and center. The primary outcome measure is the percentage of patients with postoperative hypoxemia one hour after tracheal extubation. Secondary outcome measures are postoperative pulmonary complications, need for noninvasive ventilation and intubation for respiratory failure. DISCUSSION: The OPERA trial is the first randomized controlled study powered to investigate whether early application of HFNC following extubation after abdominal surgery prevents against postoperative hypoxemia and pulmonary complications. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01887015

Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm

OnLine Journal Article Number : R116 The electronic version of this article is the complete one and can be found online at: http://ccforum.com/content/12/5/R116International audienceINTRODUCTION: Controlled mechanical ventilation (CMV) induces profound modifications of diaphragm protein metabolism, including muscle atrophy and severe ventilator-induced diaphragmatic dysfunction. Diaphragmatic modifications could be decreased by spontaneous breathing. We hypothesized that mechanical ventilation in pressure support ventilation (PSV), which preserves diaphragm muscle activity, would limit diaphragmatic protein catabolism. METHODS: Forty-two adult Sprague-Dawley rats were included in this prospective randomized animal study. After intraperitoneal anesthesia, animals were randomly assigned to the control group or to receive 6 or 18 hours of CMV or PSV. After sacrifice and incubation with 14C-phenylalanine, in vitro proteolysis and protein synthesis were measured on the costal region of the diaphragm. We also measured myofibrillar protein carbonyl levels and the activity of 20S proteasome and tripeptidylpeptidase II. RESULTS: Compared with control animals, diaphragmatic protein catabolism was significantly increased after 18 hours of CMV (33%, P = 0.0001) but not after 6 hours. CMV also decreased protein synthesis by 50% (P = 0.0012) after 6 hours and by 65% (P < 0.0001) after 18 hours of mechanical ventilation. Both 20S proteasome activity levels were increased by CMV. Compared with CMV, 6 and 18 hours of PSV showed no significant increase in proteolysis. PSV did not significantly increase protein synthesis versus controls. Both CMV and PSV increased protein carbonyl levels after 18 hours of mechanical ventilation from +63% (P < 0.001) and +82% (P < 0.0005), respectively. CONCLUSIONS: PSV is efficient at reducing mechanical ventilation-induced proteolysis and inhibition of protein synthesis without modifications in the level of oxidative injury compared with continuous mechanical ventilation. PSV could be an interesting alternative to limit ventilator-induced diaphragmatic dysfunction

Refeeding syndrome influences outcome of anorexia nervosa patients in intensive care unit: an observational study

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A recruitment maneuver increases oxygenation after intubation of hypoxemic intensive care unit patients: a randomized controlled study

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