IntroductionThe use of a system for continuous control of endotracheal tube cuff pressure reduced the incidence of ventilator-associated pneumonia (VAP) in one randomized controlled trial (RCT) with 112 patients but not in another RCT with 142 patients. In several guidelines on the prevention of VAP, the use of a system for continuous or intermittent control of endotracheal cuff pressure is not reviewed. The objective of this study was to compare the incidence of VAP in a large sample of patients (n = 284) treated with either continuous or intermittent control of endotracheal tube cuff pressure.MethodsWe performed a prospective observational study of patients undergoing mechanical ventilation during more than 48 hours in an intensive care unit (ICU) using either continuous or intermittent endotracheal tube cuff pressure control. Multivariate logistic regression analysis (MLRA) and Cox proportional hazard regression analysis were used to predict VAP. The magnitude of the effect was expressed as odds ratio (OR) or hazard ratio (HR), respectively, and 95% confidence interval (CI).ResultsWe found a lower incidence of VAP with the continuous (n = 150) than with the intermittent (n = 134) pressure control system (22.0% versus 11.2%; p = 0.02). MLRA showed that the continuous pressure control system (OR = 0.45; 95% CI = 0.22-0.89; p = 0.02) and the use of an endotracheal tube incorporating a lumen for subglottic secretion drainage (SSD) (OR = 0.39; 95% CI = 0.19-0.84; p = 0.02) were protective factors against VAP. Cox regression analysis showed that the continuous pressure control system (HR = 0.45; 95% CI = 0.24-0.84; p = 0.01) and the use of an endotracheal tube incorporating a lumen for SSD (HR = 0.29; 95% CI = 0.15-0.56; p < 0.001) were protective factors against VAP. However, the interaction between type of endotracheal cuff pressure control system (continuous or intermittent) and endotracheal tube (with or without SSD) was not statistically significant in MLRA (OR = 0.41; 95% CI = 0.07-2.37; p = 0.32) or in Cox analysis (HR = 0.35; 95% CI = 0.06-1.84; p = 0.21).ConclusionsThe use of a continuous endotracheal cuff pressure control system and/or an endotracheal tube with a lumen for SSD could help to prevent VAP in patients requiring more than 48 hours of mechanical ventilation.

IntroductionThere is a hyperoxidative state in sepsis. The objective of this study was to determine serum malondialdehyde (MDA) levels during the first week of follow up, whether such levels are associated with severity during the first week and whether non-surviving patients showed higher MDA levels than survivors during the first week.MethodsWe performed an observational, prospective, multicenter study in six Spanish Intensive Care Units. Serum levels of MDA were measured in 328 patients (215 survivors and 113 non-survivors) with severe sepsis at days one, four and eight of diagnosis, and in 100 healthy controls. The primary endpoint was 30-day mortality and the secondary endpoint was six -month mortality. The association between continuous variables was carried out using Spearman’s rank correlation coefficient. Cox regression analysis was applied to determine the independent contribution of serum MDA levels on the prediction of 30-day and 6-month mortality. Hazard ratio (HR) and 95% confidence intervals (CI) were calculated as measures of the clinical impact of the predictor variables.ResultsWe found higher serum MDA in septic patients at day one (p < 0.001), day four (p < 0.001) and day eight (p < 0.001) of diagnosis than in healthy controls. Serum MDA was lower in surviving than non-surviving septic patients at day one (p < 0.001), day four (p < 0.001) and day eight (p < 0.001). Serum MDA levels were positively correlated with lactic acid and SOFA during the first week. Finally, serum MDA levels were associated with 30-day mortality (HR = 1.05; 95% CI = 1.02-1.09; p = 0.005) and six-month mortality (hazard ratio (HR) = 1.05; 95% CI = 1.02-1.09; p = 0.003) after controlling for lactic acid levels, acute physiology and chronic health evaluation (APACHE)-II, diabetes mellitus, bloodstream infection and chronic renal failure.ConclusionsTo our knowledge, this is the largest series providing data on the oxidative state in septic patients to date. The novel finding is that high serum MDA levels sustained throughout the first week of follow up were associated with severity and mortality in septic patients.

ObjectiveMatrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play a role in neuroinflammation after brain trauma injury (TBI). Previous studies with small sample size have reported higher circulating MMP-2 and MMP-9 levels in patients with TBI, but no association between those levels and mortality. Thus, the aim of this study was to determine whether serum TIMP-1 and MMP-9 levels are associated with mortality in patients with severe TBI.MethodsThis was a multicenter, observational and prospective study carried out in six Spanish Intensive Care Units. Patients with severe TBI defined as Glasgow Coma Scale (GCS) lower than 9 were included, while those with Injury Severity Score (ISS) in non-cranial aspects higher than 9 were excluded. Serum levels of TIMP-1, MMP-9 and tumor necrosis factor (TNF)-alpha, and plasma levels of tissue factor (TF) and plasminogen activator inhibitor (PAI)-1 plasma were measured in 100 patients with severe TBI at admission. Endpoint was 30-day mortality.ResultsNon-surviving TBI patients (n = 27) showed higher serum TIMP-1 levels than survivor ones (n = 73). We did not find differences in MMP-9 serum levels. Logistic regression analysis showed that serum TIMP-1 levels were associated 30-day mortality (OR = 1.01; 95% CI = 1.001–1.013; P = 0.03). Survival analysis showed that patients with serum TIMP-1 higher than 220 ng/mL presented increased 30-day mortality than patients with lower levels (Chi-square = 5.50; P = 0.02). The area under the curve (AUC) for TIMP-1 as predictor of 30-day mortality was 0.73 (95% CI = 0.624–0.844; P<0.001). An association between TIMP-1 levels and APACHE-II score, TNF- alpha and TF was found.ConclusionsThe most relevant and new findings of our study, the largest series reporting data on TIMP-1 and MMP-9 levels in patients with severe TBI, were that serum TIMP-1 levels were associated with TBI mortality and could be used as a prognostic biomarker of mortality in TBI patients.

We studied airway occlusion pressure (P 0.1) and maximal inspiratory pressure (PIMax) in 10 healthy volunteers (Group A), 10 early postsurgical cardiac patients on spontaneous breathing (Group B), 10 patients mechanically ventilated for ARF (Group C), 10 patients weaning from mechanical ventilation after ARF (Group D) and 10 patients extubated after post-ARF (Group E). We calculated the index P 0.1/PIMax in an attempt to link the ventilatory demands and muscle ventilatory reserve. We found that the sensitivity and specificity in diagnosing the need for either full (C), partial (D) or no ventilatory support (A, B, E) by means of the P 0.1 were C = (50%, 95%), D = (70%, 72%) and A + B + E = (83%, 90%) respectively. When the index P 0.1/PIMax was used they were C = (90%, 100%), D = (80%, 87%) and A + B + E = (86%, 90%). We conclude that the index P 0.1/PIMax increases the reliability of P 0.1 alone to correctly classify the patients that will need either full, partial or no ventilatory support in ARF.

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