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BACKGROUND: Driving pressure (ΔP) has been described as a risk factor for mortality in patients with ARDS. However, the role of ΔP in the outcome of patients without ARDS and on mechanical ventilation has received less attention. Our objective was to evaluate the association between ΔP on the first day of mechanical ventilation with the development of ARDS. METHODS: This was a post hoc analysis of a multicenter, prospective, observational, international study that included subjects who were on mechanical ventilation for > 12 h. Our objective was to evaluate the association between ΔP on the first day of mechanical ventilation with the development of ARDS. To assess the effect of ΔP, a logistic regression analysis was performed when adjusting for other potential risk factors. Validation of the results obtained was performed by using a bootstrap method and by repeating the same analyses at day 2. RESULTS: A total of 1,575 subjects were included, of whom 65 (4.1%) developed ARDS. The ΔP was independently associated with ARDS (odds ratio [OR] 1.12, 95% CI 1.07–1.18 for each cm H(2)O of ΔP increase, P < .001). The same results were observed at day 2 (OR 1.14, 95% CI 1.07–1.21; P < .001) and after bootstrap validation (OR 1.13, 95% CI 1.04–1.22; P < .001). When taking the prevalence of ARDS in the lowest quartile of ΔP (≤9 cm H(2)O) as a reference, the subjects with ΔP > 12–15 cm H(2)O and those with ΔP > 15 cm H(2)O presented a higher probability of ARDS (OR 3.65, 95% CI 1.32–10.04 [P = .01] and OR 7.31, 95% CI, 2.89–18.50 [P < .001], respectively). CONCLUSIONS: In the subjects without ARDS, a higher level of ΔP on the first day of mechanical ventilation was associated with later development of ARDS. (ClinicalTrials.gov registration NCT02731898.)

The effectiveness of humidified high flow nasal cannula (HFNC) in lung transplant (LTx) recipients readmitted to intensive care unit (ICU) because of acute respiratory failure (ARF) has not been determined to date.Retrospective analysis of a prospectively assessed cohort of LTx patients who were readmitted to ICU because of ARF over a 5-year period. Patients received conventional oxygen therapy (COT) or HFNC (Optiflow, FisherPaykel, New Zealand) supportive therapy according to the attending physician's criteria. Treatment failure was defined as the need for subsequent mechanical ventilation (MV).Thirty-seven LTx recipients required ICU readmission, with a total of 40 episodes (18 COT vs. 22 HFNC). At ICU admission, no differences in comorbidities, pulmonary function, or median sequential organ failure assessment (COT, 4 [interquartile range, 4-6] vs. HFNC, 4 [interquartile range, 4-7]; P = 0.51) were observed. Relative risk of MV in patients with COT was 1.50 (95% confidence interval [95% CI], 1.02-2.21). The absolute risk reduction for MV with HFNC was 29.8%, and the number of patients needed to treat to prevent one intubation with HFNC was 3. Multivariate analysis showed that HFNC therapy was the only variable at ICU admission associated with a decreased risk of MV (odds ratio, 0.11 [95% CI, 0.02-0.69]; P = 0.02). Moreover, nonventilated patients had an increased survival rate (20.7% vs. 100%; relative rate 4.83 [95% CI, 2.37-9.86]; P0.001). No adverse events were associated with HFNC use.HFNC O2 therapy is feasible and safe and may decrease the need for MV in LTx recipients readmitted to the ICU because of ARF.

BACKGROUND: Primary graft dysfunction (PGD) remains a significant cause of lung transplant postoperative morbidity and mortality. The underlying mechanisms of PGD development are not completely understood. This study analyzed the effect of right ventricular function (RVF) on PGD development. METHODS: A retrospective analysis of a prospectively assessed cohort was performed at a single institution between July 2010 and June 2013. The primary outcome was development of PGD grade 3 (PGD3). Conventional echocardiographic parameters and speckle-tracking echocardiography, performed during the pre-transplant evaluation phase up to 1 year before surgery, were used to assess preoperative RVF./nRESULTS: Included were 120 lung transplant recipients (LTr). Systolic pulmonary arterial pressure (48 ± 20 vs 41 ± 18 mm Hg; p = 0.048) and ischemia time (349 ± 73 vs 306 ± 92 minutes; p < 0.01) were higher in LTr who developed PGD3. Patients who developed PGD3 had better RVF estimated by basal free wall longitudinal strain (BLS; -24% ± 9% vs -20% ± 6%; p = 0.039) but had a longer intensive care unit length of stay and mechanical ventilation and higher 6-month mortality. BLS ≥ -21.5% was the cutoff that best identified patients developing PGD3 (area under the receiver operating characteristic curve, 0.70; 95% confidence interval, 0.54-0.85; p = 0.020). In the multivariate analysis, a BLS ≥ -21.5% was an independent risk factor for PGD3 development (odds ratio, 4.56; 95% confidence interval, 1.20-17.38; p = 0.026), even after adjusting for potential confounding. CONCLUSIONS: A better RVF, as measured by BLS, is a risk factor for severe PGD. Careful preoperative RVF assessment using speckle-tracking echocardiography may identify LTrs with the highest risk of developing PGD. Dr. Pérez-Terán is granted by a “Rio Hortega”grant (Ref. CM12/00216)from the Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación.

Introduction We investigated the effects on hemodynamics and gas exchange of a lipid emulsion enriched with omega-3 fatty acids in patients with ARDS. Methods The design was a prospective, randomized, double-blind, parallel group study in our Intensive Medicine Department of Vall d'Hebron University Hospital (Barcelona-Spain). We studied 16 consecutive patients with ARDS and intolerance to enteral nutrition (14 men and 2 women; mean age: 58 ± 13 years; APACHE II score: 17.8 ± 2.3; Lung Injury Score: 3.1 ± 0.5; baseline PaO2/FiO2 ratio: 149 ± 40). Patients were randomized into 2 groups: Group A (n = 8) received the study emulsion Lipoplus® 20%, B.Braun Medical (50% MCT, 40% LCT, 10% ω-3); Group B (n = 8) received the control emulsion Intralipid® Fresenius Kabi (100% LCT). Lipid emulsions were administered during 12 h at a dose of 0.12 g/kg/h. Measurements of the main hemodynamic and gas exchange parameters were made at baseline (immediately before administration of the lipid emulsions), every hour during the lipid infusion, at the end of administration, and six hours after the end of administration lipid infusion. Results No statistically significant changes were observed in the different hemodynamic values analyzed. Likewise, the gas exchange parameters did not show statistically significant differences during the study. No adverse effect attributable to the lipid emulsions was seen in the patients analyzed. Conclusion The lipid emulsion enriched with omega-3 fatty acids was safe and well tolerated in short-term administration to patients with ARDS. It did not cause any significant changes in hemodynamic and gas exchange parameters. Trial registration ISRCTN63673813

To study the major eicosanoids implicated in the pathophysiology of acute respiratory distress syndrome (ARDS) in order to estimate their relative prognostic values.We conducted a prospective study in a consecutive series of patients with ARDS admitted to a university hospital intensive care unit. We measured the plasma concentrations of 3 inflammatory mediators (thromboxane B(2), 6-keto prostaglandin F(1alpha), and leukotriene B(4)) in peripheral arterial and mixed venous plasma samples.We studied 16 patients with ARDS, who had a mean alpha SD baseline ratio of P(aO(2)) to fraction of inspired oxygen (P(aO(2))/F(IO(2))) of 147 +/- 37 mm Hg and a mean +/- SD baseline lung injury score of 2.9 +/- 0.37. The plasma concentrations of thromboxane B(2), 6-keto prostaglandin F(1alpha), and leukotriene B(4) were greater than the general-population reference levels in both arterial and mixed venous plasma, but only leukotriene B(4) was higher in arterial plasma than in mixed venous plasma (401 +/- 297 pg/mL vs 316 +/- 206 pg/mL, p = 0.04). When we correlated the eicosanoid concentrations with specific indicators of clinical severity, we found correlations only between the baseline P((aO2))/F(IO(2)) and the arterial thromboxane B(2) level (r = -0.57, p = 0.02), the arterial leukotriene B(4) level (r = -0.59, p = 0.01), and the transpulmonary gradient of leukotriene B(4) level (r = -0.59, p = 0.01). We also found a correlation between the transpulmonary gradient of leukotriene B(4) and the lung injury score (r = 0.51, p = 0.04). The thromboxane B(2) concentration in arterial plasma and the leukotriene B(4) concentration in both arterial and mixed venous plasma were the only baseline plasma eicosanoid concentrations that predicted significant differences in outcome. When looking at the transpulmonary gradient of the eicosanoids studied, we found that only the gradient of leukotriene B(4) showed significant differences of clinical interest. Among survivors we observed practically no gradient (-4.9%), whereas among nonsurvivors we found a substantial positive gradient of 41.6% for the elevated arterial (post-pulmonary) values, compared with the pulmonary-artery (pre-pulmonary) values, and this difference was statistically significant (p = 0.02).The pro-inflammatory eicosanoid leukotriene B(4) showed the best correlation with lung-injury severity and outcome in patients with ARDS.