PragmaTic, prospEctive, randomized, controlled, double-blind, mulTi-centre, multinational study on the safety and efficacy of a 6% HydroxYethyl Starch (HES) solution versus an electrolyte solution in trauma patients: study protocol for the TETHYS study.

BACKGROUND: Trauma may be associated with significant to life-threatening blood loss, which in turn may increase the risk of complications and death, particularly in the absence of adequate treatment. Hydroxyethyl starch (HES) solutions are used for volume therapy to treat hypovolemia due to acute blood loss to maintain or re-establish hemodynamic stability with the ultimate goal to avoid organ hypoperfusion and cardiovascular collapse. The current study compares a 6% HES 130 solution (Volulyte 6%) versus an electrolyte solution (Ionolyte) for volume replacement therapy in adult patients with traumatic injuries, as requested by the European Medicines Agency to gain more insights into the safety and efficacy of HES in the setting of trauma care. METHODS: TETHYS is a pragmatic, prospective, randomized, controlled, double-blind, multicenter, multinational trial performed in two parallel groups. Eligible consenting adults ≥ 18 years, with an estimated blood loss of ≥ 500 ml, and in whom initial surgery is deemed necessary within 24 h after blunt or penetrating trauma, will be randomized to receive intravenous treatment at an individualized dose with either a 6% HES 130, or an electrolyte solution, for a maximum of 24 h or until reaching the maximum daily dose of 30 ml/kg body weight, whatever occurs first. Sample size is estimated as 175 patients per group, 350 patients total (α = 0.025 one-tailed, power 1-ß = 0.8). Composite primary endpoint evaluated in an exploratory manner will be 90-day mortality and 90-day renal failure, defined as AKIN stage ≥ 2, RIFLE injury/failure stage, or use of renal replacement therapy (RRT) during the first 3 months. Secondary efficacy and safety endpoints are fluid administration and balance, changes in vital signs and hemodynamic status, changes in laboratory parameters including renal function, coagulation, and inflammation biomarkers, incidence of adverse events during treatment period, hospital, and intensive care unit (ICU) length of stay, fitness for ICU or hospital discharge, and duration of mechanical ventilation and/or RRT. DISCUSSION: This pragmatic study will increase the evidence on safety and efficacy of 6% HES 130 for treatment of hypovolemia secondary to acute blood loss in trauma patients. TRIAL REGISTRATION: Registered in EudraCT, No.: 2016-002176-27 (21 April 2017) and ClinicalTrials.gov, ID: NCT03338218 (09 November 2017).

Prospective, randomized, controlled, double-blind, multi-center, multinational study on the safety and efficacy of 6% Hydroxyethyl starch (HES) sOlution versus an Electrolyte solutioN In patients undergoing eleCtive abdominal Surgery: study protocol for the PHOENICS study.

BACKGROUND: Hydroxyethyl starch (HES) solutions are used for volume therapy to treat hypovolemia due to acute blood loss and to maintain hemodynamic stability. This study was requested by the European Medicines Agency (EMA) to provide more evidence on the long-term safety and efficacy of HES solutions in the perioperative setting. METHODS: PHOENICS is a randomized, controlled, double-blind, multi-center, multinational phase IV (IIIb) study with two parallel groups to investigate non-inferiority regarding the safety of a 6% HES 130 solution (Volulyte 6%, Fresenius Kabi, Germany) compared with a crystalloid solution (Ionolyte, Fresenius Kabi, Germany) for infusion in patients with acute blood loss during elective abdominal surgery. A total of 2280 eligible patients (male and female patients willing to participate, with expected blood loss ≥ 500 ml, aged > 40 and ≤ 85 years, and ASA Physical status II-III) are randomly assigned to receive either HES or crystalloid solution for the treatment of hypovolemia due to surgery-induced acute blood loss in hospitals in up to 11 European countries. The dosing of investigational products (IP) is individualized to patients' volume needs and guided by a volume algorithm. Patients are treated with IP for maximally 24 h or until the maximum daily dose of 30 ml/kg body weight is reached. The primary endpoint is the treatment group mean difference in the change from the pre-operative baseline value in cystatin-C-based estimated glomerular filtration rate (eGFR), to the eGFR value calculated from the highest cystatin-C level measured during post-operative days 1-3. Further safety and efficacy parameters include, e.g., combined mortality/major post-operative complications until day 90, renal function, coagulation, inflammation, hemodynamic variables, hospital length of stay, major post-operative complications, and 28-day, 90-day, and 1-year mortality. DISCUSSION: The study will provide important information on the long-term safety and efficacy of HES 130/0.4 when administered according to the approved European product information. The results will be relevant for volume therapy of surgical patients. TRIAL REGISTRATION: EudraCT 2016-002162-30 . ClinicalTrials.gov NCT03278548.

Effects of remote ischemic postconditioning on HIF-1α and other markers in on-pump cardiac surgery.

BACKGROUND: There is a lack of data about the effects of remote ischemic postconditioning (RIPostC) on hypoxia-inducible factor-1α (HIF-1α) plasma levels after on-pump cardiac surgery (OPCS). This study aimed to measure the effects of RIPostC on postoperative HIF-1α plasma levels, cardiac markers and arterial oxygenation in patients undergoing OPCS. METHODS: This single-centre randomized, double blind, controlled trial, enrolled 70 patients (35 control and 35 RIPostC). RIPostC was performed by 3 cycles (5 min of ischemia followed by 5 min of reperfusion) administered in upper arm immediately after the pump period. The primary outcome was to measure HIF-1α plasma levels: before surgery (T0), and 2 h (T1), 8 h (T2), 24 h (T3), 36 h (T4) and 48 h (T5) after RIPostC. As secondary endpoint, Troponin T, CK-MB, CPK plasma levels and PaO2/FiO2 ratio were measured. RESULTS: HIF-1α plasma levels were increased at T1-T3 compared to T0 in both groups (P < 0.001). In the RIPostC group HIF-1α increased compared to the control group: differences between means (95% CI) were 0.034 (0.006-0.06) P = 0.019 at T1; 0.041 (0.013-0.069) P = 0.005 at T2; and 0.021 (0.001-0.042) P = 0.045 at T3. PaO2/FiO2 was higher in the RIPostC group than in the control group: at T3, T4 and T5. Moreover, Troponin T, CK-MB and CPK values decreased in the RIPostC group compared to the control group. CONCLUSIONS: HIF-1α plasma levels increased in control patients during for at least 36 h after OPCS. RIPostC resulted in even higher HIF-1α levels during at least the first 24 h and improved arterial oxygenation and cardiac markers.

Whole-Blood Mitochondrial DNA Copies Are Associated With the Prognosis of Acute Respiratory Distress Syndrome After Sepsis.

Acute respiratory distress syndrome (ARDS) is an inflammatory process of the lungs that develops primarily in response to pulmonary or systemic sepsis, resulting in a disproportionate death toll in intensive care units (ICUs). Given its role as a critical activator of the inflammatory and innate immune responses, previous studies have reported that an increase of circulating cell-free mitochondrial DNA (mtDNA) is a biomarker for fatal outcome in the ICU. Here we analyzed the association of whole-blood mtDNA (wb-mtDNA) copies with 28-day survival from sepsis and sepsis-associated ARDS. We analyzed mtDNA data from 687 peripheral whole-blood samples within 24 h of sepsis diagnosis from unrelated Spanish patients with sepsis (264 with ARDS) included in the GEN-SEP study. The wb-mtDNA copies were obtained from the array intensities of selected probes, with 100% identity with mtDNA and with the largest number of mismatches with the nuclear sequences, and normalized across the individual-probe intensities. We used Cox regression models for testing the association with 28-day survival. We observed that wb-mtDNA copies were significantly associated with 28-day survival in ARDS patients (hazard ratio = 3.65, 95% confidence interval = 1.39-9.59, p = 0.009) but not in non-ARDS patients. Our findings support that wb-mtDNA copies at sepsis diagnosis could be considered an early prognostic biomarker in sepsis-associated ARDS patients. Future studies will be needed to evaluate the mechanistic links of this observation with the pathogenesis of ARDS.

Dexamethasone treatment for the acute respiratory distress syndrome: a multicentre, randomised controlled trial.

BACKGROUND: There is no proven specific pharmacological treatment for patients with the acute respiratory distress syndrome (ARDS). The efficacy of corticosteroids in ARDS remains controversial. We aimed to assess the effects of dexamethasone in ARDS, which might change pulmonary and systemic inflammation and result in a decrease in duration of mechanical ventilation and mortality. METHODS: We did a multicentre, randomised controlled trial in a network of 17 intensive care units (ICUs) in teaching hospitals across Spain in patients with established moderate-to-severe ARDS (defined by a ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen of 200 mm Hg or less assessed with a positive end-expiratory pressure of 10 cm H2O or more and FiO2 of 0·5 or more at 24 h after ARDS onset). Patients with brain death, terminal-stage disease, or receiving corticosteroids or immunosuppressive drugs were excluded. Eligible patients were randomly assigned based on balanced treatment assignments with a computerised randomisation allocation sequence using blocks of 10 opaque, sealed envelopes to receive immediate treatment with dexamethasone or continued routine intensive care (control group). Patients in the dexamethasone group received an intravenous dose of 20 mg once daily from day 1 to day 5, which was reduced to 10 mg once daily from day 6 to day 10. Patients in both groups were ventilated with lung-protective mechanical ventilation. Allocation concealment was maintained at all sites during the trial. Primary outcome was the number of ventilator-free days at 28 days, defined as the number of days alive and free from mechanical ventilation from day of randomisation to day 28. Secondary outcome was all-cause mortality 60 days after randomisation. All analyses were done according to the intention-to-treat principle. This study is registered with ClinicalTrials.gov, NCT01731795. FINDINGS: Between March 28, 2013, and Dec 31, 2018, we enrolled 277 patients and randomly assigned 139 patients to the dexamethasone group and 138 to the control group. The trial was stopped by the data safety monitoring board due to low enrolment rate after enrolling more than 88% (277/314) of the planned sample size. The mean number of ventilator-free days was higher in the dexamethasone group than in the control group (between-group difference 4·8 days [95% CI 2·57 to 7·03]; p<0·0001). At 60 days, 29 (21%) patients in the dexamethasone group and 50 (36%) patients in the control group had died (between-group difference -15·3% [-25·9 to -4·9]; p=0·0047). The proportion of adverse events did not differ significantly between the dexamethasone group and control group. The most common adverse events were hyperglycaemia in the ICU (105 [76%] patients in the dexamethasone group vs 97 [70%] patients in the control group), new infections in the ICU (eg, pneumonia or sepsis; 33 [24%] vs 35 [25%]), and barotrauma (14 [10%] vs 10 [7%]). INTERPRETATION: Early administration of dexamethasone could reduce duration of mechanical ventilation and overall mortality in patients with established moderate-to-severe ARDS. FUNDING: Fundación Mutua Madrileña, Instituto de Salud Carlos III, The European Regional Development's Funds, Asociación Científica Pulmón y Ventilación Mecánica.

Limb Ischemic Conditioning Induces Oxidative Stress Followed by a Correlated Increase of HIF-1α in Healthy Volunteers.

BACKGROUND: Local and remote ischemic preconditioning has been used as a protective intervention against ischemia/reperfusion (I/R) damage in several preclinical and clinical studies. However, its physiological mechanisms are not completely known. I/R increases the production of reactive oxygen species, which also serve as messengers for a variety of functions. Hypoxia-inducible factor 1 alpha (HIF-1α) is probably the most important transcription factor mediator of hypoxic signaling. OBJECTIVE: We hypothesized that limb ischemic conditioning (LIC) induces a local oxidative/nitrosative stress and a correlated increase of HIF-1α plasma levels. METHODS: An observational, prospective, and single-center study has been conducted in 27 healthy volunteers. LIC was applied: three cycles (5 min of ischemia followed by 5 min of reperfusion) using an ischemia cuff placed on the upper left arm. Time course of 8-isoprostane, nitrite, and HIF-1α levels was measured in blood plasma. Venous blood was sampled from the left arm before tourniquet inflation (basal) and after LIC: 1 min and 2 hr for 8-isoprostane and nitrite; and 1 min, 2 hr, 8 hr, 24 hr, and 48 hr for HIF-1α. RESULTS: After LIC, we have found an early increase of 8-isoprostane and nitrite. HIF-1α increased at 2 and 8 hr after LIC. We found a direct correlation between HIF-1α and 8-isoprostane and nitrite plasma levels. CONCLUSIONS: We concluded that LIC induces an early oxidative/nitrosative stress in the arm followed by an increase of HIF-1α plasma levels correlated with 8-isoprostane and nitrite levels, possibly as a local response.

A noninvasive postoperative clinical score to identify patients at risk for postoperative pulmonary complications: the Air-Test Score.

BACKGROUND: Postoperative pulmonary complications (PPCs) negatively affect morbidity, healthcare costs and postsurgical survival. Preoperative and intraoperative peripheral oxyhemoglobin saturation (SpO2) levels are independent risk factors for postoperative pulmonary complications (PPCs). The air-test assesses the value of SpO2 while breathing room-air. We aimed at building a clinical score that includes the air-test for predicting the risk for PPCs. METHODS: This is a development and validation study in patients -randomly divided into two cohorts- from a large randomized clinical trial (iPROVE) that enrolled 964 intermediate-to-high risk patients scheduled for abdominal surgery. Arterial oxygenation was assessed on room-air in the preoperative period (preoperative air-test) and 3h after admission to the postoperative care unit (postoperative air-test). The air-test was defined as positive or negative if SpO2 was ≤96% or >96%, respectively. Positive air-tests were stratified into weak (93-96%) or strong (<93%). The primary outcome was a composite of moderate-to-severe PPCs during the first seven postoperative days. RESULTS: A total of 902 patients were included in the final analysis (542 in the development cohort and 360 in the validation cohort). Regression analysis identified five independent risk factors for PPC: age, type of surgery, pre- and postoperative air-test, and atelectasis. The area under the receiver operating characteristic curve (AUC) was 0.79 (95% CI: 0.75-0.82) when including these five independent predictors. We built a simplified score termed "air-test score" by using only the pre- and postoperative SpO2, resulting in an AUC of 0.72 (95% CI: 0.67-0.76) for the derivation and 0.72 (95% CI: 0.66-0.78) for the validation cohort, respectively. The air-test score stratified patients into four levels of risk, with PPCs ranging from <15% to >75%. CONCLUSIONS: The simple, non-invasive and inexpensive bedside air-test score, evaluating pre- and postoperatively SpO2 measured on room-air, helps to predict the risk for PPCs.

Rationale and Study Design for an Individualized Perioperative Open Lung Ventilatory Strategy in Patients on One-Lung Ventilation (iPROVE-OLV).

OBJECTIVE: The aim of this clinical trial is to examine whether it is possible to reduce postoperative complications using an individualized perioperative ventilatory strategy versus using a standard lung-protective ventilation strategy in patients scheduled for thoracic surgery requiring one-lung ventilation. DESIGN: International, multicenter, prospective, randomized controlled clinical trial. SETTING: A network of university hospitals. PARTICIPANTS: The study comprises 1,380 patients scheduled for thoracic surgery. INTERVENTIONS: The individualized group will receive intraoperative recruitment maneuvers followed by individualized positive end-expiratory pressure (open lung approach) during the intraoperative period plus postoperative ventilatory support with high-flow nasal cannula, whereas the control group will be managed with conventional lung-protective ventilation. MEASUREMENTS AND MAIN RESULTS: Individual and total number of postoperative complications, including atelectasis, pneumothorax, pleural effusion, pneumonia, acute lung injury; unplanned readmission and reintubation; length of stay and death in the critical care unit and in the hospital will be analyzed for both groups. The authors hypothesize that the intraoperative application of an open lung approach followed by an individual indication of high-flow nasal cannula in the postoperative period will reduce pulmonary complications and length of hospital stay in high-risk surgical patients.

A Prognostic Enrichment Strategy for Selection of Patients With Acute Respiratory Distress Syndrome in Clinical Trials.

OBJECTIVES: Incomplete or ambiguous evidence for identifying high-risk patients with acute respiratory distress syndrome for enrollment into randomized controlled trials has come at the cost of an unreasonable number of negative trials. We examined a set of selected variables early in acute respiratory distress syndrome to determine accurate prognostic predictors for selecting high-risk patients for randomized controlled trials. DESIGN: A training and testing study using a secondary analysis of data from four prospective, multicenter, observational studies. SETTING: A network of multidisciplinary ICUs. PATIENTS: We studied 1,200 patients with moderate-to-severe acute respiratory distress syndrome managed with lung-protective ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We evaluated different thresholds for patient's age, PaO2/FIO2, plateau pressure, and number of extrapulmonary organ failures to predict ICU outcome at 24 hours of acute respiratory distress syndrome diagnosis. We generated 1,000 random scenarios as training (n = 900, 75% of population) and testing (n = 300, 25% of population) datasets and averaged the logistic coefficients for each scenario. Thresholds for age (< 50, 50-70, > 70 yr), PaO2/FIO2 (≤ 100, 101-150, > 150 mm Hg), plateau pressure (< 29, 29-30, > 30 cm H2O), and number of extrapulmonary organ failure (< 2, 2, > 2) stratified accurately acute respiratory distress syndrome patients into categories of risk. The model that included all four variables proved best to identify patients with the highest or lowest risk of death (area under the receiver operating characteristic curve, 0.86; 95% CI, 0.84-0.88). Decision tree analyses confirmed the accuracy and robustness of this enrichment model. CONCLUSIONS: Combined thresholds for patient's age, PaO2/FIO2, plateau pressure, and extrapulmonary organ failure provides prognostic enrichment accuracy for stratifying and selecting acute respiratory distress syndrome patients for randomized controlled trials.

A vascular endothelial growth factor receptor gene variant is associated with susceptibility to acute respiratory distress syndrome.

BACKGROUND: The acute respiratory distress syndrome (ARDS) is one of the main causes of mortality in adults admitted to intensive care units. Previous studies have demonstrated the existence of genetic variants involved in the susceptibility and outcomes of this syndrome. We aimed to identify novel genes implicated in sepsis-induced ARDS susceptibility. METHODS: We first performed a prioritization of candidate genes by integrating our own genomic data from a transcriptomic study in an animal model of ARDS and from the only published genome-wide association study of ARDS study in humans. Then, we selected single nucleotide polymorphisms (SNPs) from prioritized genes to conduct a case-control discovery association study in patients with sepsis-induced ARDS (n = 225) and population-based controls (n = 899). Finally, we validated our findings in an independent sample of 661 sepsis-induced ARDS cases and 234 at-risk controls. RESULTS: Three candidate genes were prioritized: dynein cytoplasmic-2 heavy chain-1, fms-related tyrosine kinase 1 (FLT1), and integrin alpha-1. Of those, a SNP from FLT1 gene (rs9513106) was associated with ARDS in the discovery study, with an odds ratio (OR) for the C allele of 0.76, 95% confidence interval (CI) 0.58-0.98 (p = 0.037). This result was replicated in an independent study (OR = 0.78, 95% CI = 0.62-0.98, p = 0.039), showing consistent direction of effects in a meta-analysis (OR = 0.77, 95% CI = 0.65-0.92, p = 0.003). CONCLUSIONS: We identified FLT1 as a novel ARDS susceptibility gene and demonstrated that integration of genomic data can be a valid procedure to identify novel susceptibility genes. These results contribute to previous firm associations and functional evidences implicating FLT1 gene in other complex traits that are mechanistically linked, through the key role of endothelium, to the pathophysiology of ARDS.

The Effects of an Open-Lung Approach During One-Lung Ventilation on Postoperative Pulmonary Complications and Driving Pressure: A Descriptive, Multicenter National Study.

OBJECTIVE: Thoracic surgical procedures are associated with an increased risk of postoperative pulmonary complications (PPCs), which seem to be related directly to intraoperative driving pressure. The authors conducted this study to describe the incidence of PPCs in patients in whom an individualized open-lung approach was applied during one-lung ventilation. DESIGN: This was a prospective, multicenter, national descriptive study. SETTING: Thoracic surgery patients undergoing one-lung ventilation. PARTICIPANTS: Eligible participants were included consecutively from October 1, 2016, to September 30, 2017. A total of 690 patients were included. INTERVENTIONS: An individualized open-lung approach that consisted of an alveolar recruitment maneuver followed by a positive end-expiratory pressure adjusted to best respiratory system compliance was performed in all patients. MEASUREMENTS AND MAIN RESULTS: Preoperative and intraoperative data were recorded; the primary outcome was a description of the incidence of PPCs in these patients during the first 7 postoperative days. The patients were mainly male, and half of them had a high risk of PPCs (ARISCAT score exceeding 44). Eleven percent of participants developed a PPC within the first postoperative week. The mean open lung positive end-expiratory pressure was 8 ± 3 cmH2O. When compared with pre-open lung approach values, the open-lung approach significantly decreased the driving pressure (14 ± 4 cmH2O v 11 ± 3 cmH2O; p < 0.001) and increased dynamic compliance (30 ± 10 mL/cmH2O v 43 ±15 mL/cmH2O; p < 0.001). CONCLUSIONS: The low incidence of PPCs in patients who underwent an open-lung approach during one-lung ventilation compared with that reported for other thoracic surgery series and the decrease in the driving pressure in these patients justify an additional randomized controlled trial to compare the open-lung approach with the standard protective strategy of low tidal volume and low positive end-expiratory pressure.

Individualized, perioperative, hemodynamic goal-directed therapy in major abdominal surgery (iPEGASUS trial): study protocol for a randomized controlled trial.

BACKGROUND: Postoperative morbidity and mortality in patients undergoing surgery is high, especially in patients who are at risk of complications and undergoing major surgery. We hypothesize that perioperative, algorithm-driven, hemodynamic therapy based on individualized fluid status and cardiac output optimization is able to reduce mortality and postoperative moderate and severe complications as a major determinant of the patients' postoperative quality of life, as well as health care costs. METHODS/DESIGN: This is a multi-center, international, prospective, randomized trial in 380 patients undergoing major abdominal surgery including visceral, urological, and gynecological operations. Eligible patients will be randomly allocated to two treatment arms within the participating centers. Patients of the intervention group will be treated perioperatively following a specific hemodynamic therapy algorithm based on pulse-pressure variation (PPV) and individualized optimization of cardiac output assessed by pulse-contour analysis (ProAQT© device; Pulsion Medical Systems, Feldkirchen, Germany). Patients in the control group will be treated according to standard local care based on established basic hemodynamic treatment. The primary endpoint is a composite comprising the occurrence of moderate or severe postoperative complications or death within 28 days post surgery. Secondary endpoints are: (1) the number of moderate and severe postoperative complications in total, per patient and for each individual complication; (2) the occurrence of at least one of these complications on days 1, 3, 5, 7, and 28 in total and for every complication; (3) the days alive and free of mechanical ventilation, vasopressor therapy and renal replacement therapy, length of intensive care unit, and hospital stay at day 7 and day 28; and (4) mortality and quality of life, assessed by the EQ-5D-5L™ questionnaire, after 6 months. DISCUSSION: This is a large, international randomized controlled study evaluating the effect of perioperative, individualized, algorithm-driven ,hemodynamic optimization on postoperative morbidity and mortality. TRIAL REGISTRATION: Trial registration: NCT03021525 . Registered on 12 January 2017.

Individualised perioperative open-lung approach versus standard protective ventilation in abdominal surgery (iPROVE): a randomised controlled trial.

BACKGROUND: The effects of individualised perioperative lung-protective ventilation (based on the open-lung approach [OLA]) on postoperative complications is unknown. We aimed to investigate the effects of intraoperative and postoperative ventilatory management in patients scheduled for abdominal surgery, compared with standard protective ventilation. METHODS: We did this prospective, multicentre, randomised controlled trial in 21 teaching hospitals in Spain. We enrolled patients who were aged 18 years or older, were scheduled to have abdominal surgery with an expected time of longer than 2 h, had intermediate-to-high-risk of developing postoperative pulmonary complications, and who had a body-mass index less than 35 kg/m2. Patients were randomly assigned (1:1:1:1) online to receive one of four lung-protective ventilation strategies using low tidal volume plus positive end-expiratory pressure (PEEP): open-lung approach (OLA)-iCPAP (individualised intraoperative ventilation [individualised PEEP after a lung recruitment manoeuvre] plus individualised postoperative continuous positive airway pressure [CPAP]), OLA-CPAP (intraoperative individualised ventilation plus postoperative CPAP), STD-CPAP (standard intraoperative ventilation plus postoperative CPAP), or STD-O2 (standard intraoperative ventilation plus standard postoperative oxygen therapy). Patients were masked to treatment allocation. Investigators were not masked in the operating and postoperative rooms; after 24 h, data were given to a second investigator who was masked to allocations. The primary outcome was a composite of pulmonary and systemic complications during the first 7 postoperative days. We did the primary analysis using the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02158923. FINDINGS: Between Jan 2, 2015, and May 18, 2016, we enrolled 1012 eligible patients. Data were available for 967 patients, whom we included in the final analysis. Risk of pulmonary and systemic complications did not differ for patients in OLA-iCPAP (110 [46%] of 241, relative risk 0·89 [95% CI 0·74-1·07; p=0·25]), OLA-CPAP (111 [47%] of 238, 0·91 [0·76-1·09; p=0·35]), or STD-CPAP groups (118 [48%] of 244, 0·95 [0·80-1·14; p=0·65]) when compared with patients in the STD-O2 group (125 [51%] of 244). Intraoperatively, PEEP was increased in 69 (14%) of patients in the standard perioperative ventilation groups because of hypoxaemia, and no patients from either of the OLA groups required rescue manoeuvres. INTERPRETATION: In patients who have major abdominal surgery, the different perioperative open lung approaches tested in this study did not reduce the risk of postoperative complications when compared with standard lung-protective mechanical ventilation. FUNDING: Instituto de Salud Carlos III of the Spanish Ministry of Economy and Competitiveness, and Grants Programme of the European Society of Anaesthesiology.

A Quantile Analysis of Plateau and Driving Pressures: Effects on Mortality in Patients With Acute Respiratory Distress Syndrome Receiving Lung-Protective Ventilation.

OBJECTIVES: The driving pressure (plateau pressure minus positive end-expiratory pressure) has been suggested as the major determinant for the beneficial effects of lung-protective ventilation. We tested whether driving pressure was superior to the variables that define it in predicting outcome in patients with acute respiratory distress syndrome. DESIGN: A secondary analysis of existing data from previously reported observational studies. SETTING: A network of ICUs. PATIENTS: We studied 778 patients with moderate to severe acute respiratory distress syndrome. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We assessed the risk of hospital death based on quantiles of tidal volume, positive end-expiratory pressure, plateau pressure, and driving pressure evaluated at 24 hours after acute respiratory distress syndrome diagnosis while ventilated with standardized lung-protective ventilation. We derived our model using individual data from 478 acute respiratory distress syndrome patients and assessed its replicability in a separate cohort of 300 acute respiratory distress syndrome patients. Tidal volume and positive end-expiratory pressure had no impact on mortality. We identified a plateau pressure cut-off value of 29 cm H2O, above which an ordinal increment was accompanied by an increment of risk of death. We identified a driving pressure cut-off value of 19 cm H2O where an ordinal increment was accompanied by an increment of risk of death. When we cross tabulated patients with plateau pressure less than 30 and plateau pressure greater than or equal to 30 with those with driving pressure less than 19 and driving pressure greater than or equal to 19, plateau pressure provided a slightly better prediction of outcome than driving pressure in both the derivation and validation cohorts (p < 0.0000001). CONCLUSIONS: Plateau pressure was slightly better than driving pressure in predicting hospital death in patients managed with lung-protective ventilation evaluated on standardized ventilator settings 24 hours after acute respiratory distress syndrome onset.

Neurally adjusted ventilatory assist in patients with acute respiratory failure: study protocol for a randomized controlled trial.

BACKGROUND: Patient-ventilator asynchrony is a common problem in mechanically ventilated patients with acute respiratory failure. It is assumed that asynchronies worsen lung function and prolong the duration of mechanical ventilation (MV). Neurally Adjusted Ventilatory Assist (NAVA) is a novel approach to MV based on neural respiratory center output that is able to trigger, cycle, and regulate the ventilatory cycle. We hypothesized that the use of NAVA compared to conventional lung-protective MV will result in a reduction of the duration of MV. It is further hypothesized that NAVA compared to conventional lung-protective MV will result in a decrease in the length of ICU and hospital stay, and mortality. METHODS/DESIGN: This is a prospective, multicenter, randomized controlled trial in 306 mechanically ventilated patients with acute respiratory failure from several etiologies. Only patients ventilated for less than 5 days, and who are expected to require prolonged MV for an additional 72 h or more and are able to breathe spontaneously, will be considered for enrollment. Eligible patients will be randomly allocated to two ventilatory arms: (1) conventional lung-protective MV (n = 153) and conventional lung-protective MV with NAVA (n = 153). Primary outcome is the number of ventilator-free days, defined as days alive and free from MV at day 28 after endotracheal intubation. Secondary outcomes are total length of MV, and ICU and hospital mortality. DISCUSSION: This is the first randomized clinical trial examining, on a multicenter scale, the beneficial effects of NAVA in reducing the dependency on MV of patients with acute respiratory failure. TRIAL REGISTRATION: ClinicalTrials.gov website ( NCT01730794 ). Registered on 15 November 2012.

Evaluating the efficacy of dexamethasone in the treatment of patients with persistent acute respiratory distress syndrome: study protocol for a randomized controlled trial.

BACKGROUND: Although much has evolved in our understanding of the pathogenesis and factors affecting outcome of patients with acute respiratory distress syndrome (ARDS), still there is no specific pharmacologic treatment for ARDS. Several clinical trials have evaluated the utility of corticoids but none of them has demonstrated a definitive benefit due to small sample sizes, selection bias, patient heterogeneity, and time of initiation of treatment or duration of therapy. We postulated that adjunctive treatment of persistent ARDS with intravenous dexamethasone might change the pulmonary and systemic inflammatory response and thereby reduce morbidity, leading to a decrease in duration of mechanical ventilation and a decrease in mortality. METHODS/DESIGN: This is a prospective, multicenter, randomized, controlled trial in 314 patients with persistent moderate/severe ARDS. Persistent ARDS is defined as maintaining a PaO2/FiO2 ≤ 200 mmHg on PEEP ≥ 10 cmH2O and FiO2 ≥ 0.5 after 24 hours of routine intensive care. Eligible patients will be randomly allocated to two arms: (i) conventional treatment without dexamethasone, (ii) conventional treatment plus dexamethasone. Patients in the dexamethasone group will be treated with a daily dose of 20 mg iv from day 1 to day 5, and 10 mg iv from day 6 to day 10. Primary outcome is the number of ventilator-free days, defined as days alive and free from mechanical ventilation at day 28 after intubation. Secondary outcome is all-cause mortality at day 60 after enrollment. DISCUSSION: This study will be the largest randomized controlled clinical trial to assess the role of dexamethasone in patients with persistent ARDS. TRIAL REGISTRATION: Registered on 21 November 2012 as DEXA-ARDS at ClinicalTrials.gov website ( NCT01731795 ).

Glutathione oxidation correlates with one-lung ventilation time and PO2/FiO2 ratio during pulmonary lobectomy.

OBJECTIVES: During lung lobectomy, the operated lung completely collapses with simultaneous hypoxic pulmonary vasoconstriction, followed by expansion and reperfusion. Here, we investigated glutathione oxidation and lipoperoxidation in patients undergoing lung lobectomy, during one-lung ventilation (OLV) and after resuming two-lung ventilation (TLV), and examined the relationship with OLV duration. METHODS: We performed a single-centre, observational, prospective study in 32 patients undergoing lung lobectomy. Blood samples were collected at five time-points: T0, pre-operatively; T1, during OLV, 5 minutes before resuming TLV; and T2, T3, and T4, respectively, 5, 60, and 180 minutes after resuming TLV. Samples were tested for reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione redox potential, and malondialdehyde (MDA). RESULTS: GSSG and MDA blood levels increased at T1, and increased further at T2. OLV duration directly correlated with marker levels at T1 and T2. Blood levels of GSH and glutathione redox potential decreased at T1-T3. GSSG, oxidized glutathione/total glutathione ratio, and MDA levels were inversely correlated with arterial blood PO2/FiO2 at T1 and T2. DISCUSSION: During lung lobectomy and OLV, glutathione oxidation, and lipoperoxidation marker blood levels increase, with further increases after resuming TLV. Oxidative stress degree was directly correlated with OLV duration, and inversely correlated with arterial blood PO2/FiO2.

Oxidative lung injury correlates with one-lung ventilation time during pulmonary lobectomy: a study of exhaled breath condensate and blood.

OBJECTIVES: During lung lobectomy, the operated lung is collapsed and hypoperfused; oxygen deprivation is accompanied by reactive hypoxic pulmonary vasoconstriction. After lung lobectomy, ischaemia present in the collapsed state is followed by expansion-reperfusion and lung injury attributed to the production of reactive oxygen species. The primary objective of this study was to investigate the time course of several markers of oxidative stress simultaneously in exhaled breath condensate and blood and to determine the relationship between oxidative stress and one-lung ventilation time in patients undergoing lung lobectomy. METHODS: This single-centre, observational, prospective study included 28 patients with non-small-cell lung cancer who underwent lung lobectomy. We measured the levels of hydrogen peroxide, 8-iso-PGF2α, nitrites plus nitrates and pH in exhaled breath condensate (n = 25). The levels of 8-iso-PGF2α and nitrites plus nitrates were also measured in blood (n = 28). Blood samples and exhaled breath condensate samples were collected from all patients at five time points: preoperatively; during one-lung ventilation, immediately before resuming two-lung ventilation; immediately after resuming two-lung ventilation; 60 min after resuming two-lung ventilation and 180 min after resuming two-lung ventilation. RESULTS: Both exhaled breath condensate and blood exhibited significant and simultaneous increases in oxidative-stress markers immediately before two-lung ventilation was resumed. However, all these values underwent larger increases immediately after resuming two-lung ventilation. In both exhaled breath condensate and blood, marker levels significantly and directly correlated with the duration of one-lung ventilation immediately before resuming two-lung ventilation and immediately after resuming two-lung ventilation. Although pH significantly decreased in exhaled breath condensate immediately after resuming two-lung ventilation, these pH values were inversely correlated with the duration of one-lung ventilation. CONCLUSIONS: During lung lobectomy, the operated lung is collapsed and oxidative injury occurs, with the levels of markers of oxidative stress increasing simultaneously in exhaled breath condensate and blood during one-lung ventilation. These increases were larger after resuming two-lung ventilation. Increases immediately before resuming two-lung ventilation and immediately after resuming two-lung ventilation were directly correlated with the duration of one-lung ventilation.