Global end-diastolic volume could be more appropiate to reduce intraoperative bleeding than central venous pressure during major liver transection.

BACKGROUND: Central venous pressure often fails to identify the true value of cardiac preload. Our purpose is to investigate whether Global End-Diastolic Volume (GEDV) values can control hemodynamic parameters for the measurement of fluid volume, cardiac preload and blood loss during liver transection. METHODS: This was a prospective clinical study that included patients undergoing liver resection. All patients were monitored by means of PiCCO technology and 222 hemodynamic measurements were performed in 74 patients. Fluid restriction was used. Transpulmonary thermodilutions were performed at different times of surgery, namely: 1. at the beginning of surgery; 2. before hepatectomy and after selective vascular exclusion (Time 1); 3. approximately half way through the liver transection (Time 2); and 4. after liver resection (Time 3). RESULTS: One hundred and twenty-nine of the 222 GEDV values were decreased (prevalence of hypovolemia of 58.1%). However, twenty two of the 222 CVP values were decreased (prevalence of 10.8%). Sensitivity of CVP with regard to volume depletion (GEDV > 650 mL m-2) on the times (1, 2 and 3) were 16.28 (4.08-28.48, 95% CI), 18.18 (5.65-30.75, 95% CI) and 21.43 (7.83-35.03, 95% CI), respectively. There was no correlation between CVP and GEDV. CONCLUSIONS: GEDV values may be more appropriate for monitoring cardiac preload during liver transection.

Helmet noninvasive mechanical ventilation in patients with acute postoperative respiratory failure.

BACKGROUND: The physiological and clinical effects of noninvasive ventilation (NIV) on acute postoperative respiratory failure are relatively unknown. The aim of this study was to determine the prediction factors for failure in the use of NIV with a helmet in this context. METHODS: This was a prospective observational study. The use of NIV was assessed for a period of 2 years in a postoperative ICU. Demographic data were collected, as well as acute respiratory failure (ARF) and arterial gas readings. Hemodynamic changes were assessed using pulse contour cardiac output technology, and the clinical development of subjects was recorded. All subjects who developed ARF were treated using NIV as their primary care, depending on whether the technique was successful or the subject required intubation. The risk factors that determined failure in the application of NIV were subsequently determined. RESULTS: Of the 99 subjects presenting with postoperative ARF treated with NIV using a helmet, 74 did not require intubation (74.7%). Following a multivariate analysis using logistic regression, we determined that there are 3 independent risk factors for the failure of NIV. Three factors were associated with respiratory failure: ARDS, pneumonia, and lack of improvement with NIV in 1 hour (increase in the P(aO(2))/F(IO(2))). CONCLUSIONS: NIV using a helmet could provide an effective alternative to conventional ventilation in selected patients with postoperative ARF.