Pooled analysis of higher versus lower blood pressure targets for vasopressor therapy septic and vasodilatory shock

PURPOSE: Guidelines for shock recommend mean arterial pressure (MAP) targets for vasopressor therapy of at least 65 mmHg and, until recently, suggested that patients with underlying chronic hypertension and atherosclerosis may benefit from higher targets. We conducted an individual patient-data meta-analysis of recent trials to determine if patient variables modify the effect of different MAP targets. METHODS: We searched the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials for randomized controlled trials of higher versus lower blood pressure targets for vasopressor therapy in adult patients in shock (until November 2017). After obtaining individual patient data from both eligible trials, we used a modified version of the Cochrane Collaboration\u27s instrument to assess the risk of bias of included trials. The primary outcome was 28-day mortality. RESULTS: Included trials enrolled 894 patients. Controlling for trial and site, the OR for 28-day mortality for the higher versus lower MAP targets was 1.15 (95% CI 0.87-1.52). Treatment effect varied by duration of vasopressors before randomization (interaction p = 0.017), but not by chronic hypertension, congestive heart failure or age. Risk of death increased in higher MAP groups among patients on vasopressors > 6 h before randomization (OR 3.00, 95% CI 1.33-6.74). CONCLUSIONS: Targeting higher blood pressure targets may increase mortality in patients who have been treated with vasopressors for more than 6 h. Lower blood pressure targets were not associated with patient-important adverse events in any subgroup, including chronically hypertensive patients

Prone position for acute respiratory distress syndrome : A systematic review and meta-analysis

Rationale: The application of prone positioning for acute respiratory distress syndrome (ARDS) has evolved, with recent trials focusing on patients with more severe ARDS, and applying prone ventilation for more prolonged periods. Objectives: This review evaluates the effect of prone positioning on 28-day mortality (primary outcome) compared with conventional mechanical ventilation in the supine position for adults with ARDS. Methods: We updated the literature search from a systematic review published in 2010, searching MEDLINE, EMBASE, and CENTRAL (through to August 2016). We included randomized, controlled trials (RCTs) comparing prone to supine positioning in mechanically ventilated adults with ARDS, and conducted sensitivity analyses to explore the effects of duration of prone ventilation, concurrent lung-protective ventilation and ARDS severity. Secondary outcomes included Pa-O2/FIO2 ratio on Day 4 and an evaluation of adverse events. Meta-analyses used random effects models. Methodologic quality of the RCTs was evaluated using the Cochrane risk of bias instrument, and methodologic quality of the overall body of evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) guidelines. Results: Eight RCTs fulfilled entry criteria, and included 2,129 patients (1,093 [51%] proned). Meta-analysis revealed no difference in mortality (risk ratio [RR], 0.84; 95% confidence interval [CI], 0.68-1.04), but subgroup analyses found lower mortality with 12 hours or greater duration prone (five trials; RR, 0.74; 95% CI, 0.56-0.99) and for patients with moderate to severe ARDS (five trials; RR, 0.74; 95% CI, 0.56-0.99). Pa-O2/FIO2 ratio on Day 4 for all patients was significantly higher in the prone positioning group (mean difference, 23.5; 95% CI, 12.4-34.5). Prone positioning was associated with higher rates of endotracheal tube obstruction and pressure sores. Risk of bias was low across the trials. Conclusions: Prone positioning is likely to reduce mortality among patients with severe ARDS when applied for at least 12 hours daily

New and conventional strategies for lung recruitment in acute respiratory distress syndrome

Mechanical ventilation is a supportive and life saving therapy in patients with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Despite advances in critical care, mortality remains high. During the last decade, the fact that mechanical ventilation can produce morphologic and physiologic alterations in the lungs has been recognized. In this context, the use of low tidal volumes (VT) and limited inspiratory plateau pressure (Pplat) has been proposed when mechanically ventilating the lungs of patients with ALI/ARDS, to prevent lung as well as distal organ injury. However, the reduction in VT may result in alveolar derecruitment, cyclic opening and closing of atelectatic alveoli and distal small airways leading to ventilator-induced lung injury (VILI) if inadequate low positive end-expiratory pressure (PEEP) is applied. On the other hand, high PEEP levels may be associated with excessive lung parenchyma stress and strain and negative hemodynamic effects, resulting in systemic organ injury. Therefore, lung recruitment maneuvers have been proposed and used to open up collapsed lung, while PEEP counteracts alveolar derecruitment due to low VT ventilatio

Evolution of mechanical ventilation in response to clinical research.

RATIONALE: Recent literature in mechanical ventilation includes strong evidence from randomized trials. Little information is available regarding the influence of these trials on usual clinical practice. OBJECTIVES: To describe current mechanical ventilation practices and to assess the influence of interval randomized trials when compared with findings from a 1998 cohort. METHODS: A prospective international observational cohort study, with a nested comparative study performed in 349 intensive care units in 23 countries. We enrolled 4,968 consecutive patients receiving mechanical ventilation over a 1-month period. We recorded demographics and daily data related to mechanical ventilation for the duration of ventilation. We systematically reviewed the literature and developed 11 practice-change hypotheses for the comparative cohort study before seeing these results. In assessing practice changes, we only compared data from the 107 intensive care units (1,675 patients) that also participated in the 1998 cohort (1,383 patients). MEASUREMENTS AND MAIN RESULTS: In 2004 compared with 1998, the use of noninvasive ventilation increased (11.1 vs. 4.4%, P < 0.001). Among patients with acute respiratory distress syndrome, tidal volumes decreased (7.4 vs. 9.1 ml/kg, P < 0.001) and positive end-expiratory pressure levels increased slightly (8.7 vs. 7.7 cm H(2)O, P = 0.02). More patients were successfully extubated after their first attempt of spontaneous breathing (77 vs. 62%, P < 0.001). Use of synchronized intermittent mandatory ventilation fell dramatically (1.6 vs. 11%, P < 0.001). Observations confirmed 10 of our 11 practice-change hypotheses. CONCLUSIONS: The strong concordance of predicted and observed practice changes suggests that randomized trial results have advanced mechanical ventilation practices internationally

Mechanical ventilation in adults with acute respiratory distress syndrome: An official clinical guideline of American Thoracic Society/European Society of Intensive Care medicine/Society of Critical care medicine

The aim of this guideline is to provide clinical recommendation on the use of mechanical ventilation in adult patients with acute respiratory distress syndrome (ARDS). Methods. This guideline is based on systematic review and metaanalysis of available literature on the use of mechanical ventilation in adult patients with ARDS. Results. All patients with ARDS should be mechanically ventilated with the use of lower tidal volumes (4\u20138 ml/kg predicted bodyweight) and lower inspiratory pressures (plateau pressure, 30 cm H2O). In severe ARDS, the prone positioning for more than 12 h/d is strongly recommended. In patients with moderate to severe ARDS, routine use of high-frequency oscillatory ventilation is not recommended; conditional recommendation has been developed for the use of higher positive end-expiratory pressure and recruitment maneuvers. Cu?? \u2013 ently, there is not enough evidence for the use of extracorporeal membrane oxygenation in patients with severe ARDS. Conclusions. Practical recommendations on selected methods to co?? \u2013 ect ventilation disturbances in adult patients with ARDS have been developed. Clinicians involved in the management of patients with ARDS should use personalized approach to the treatment of these patients. Key words: acute respiratory distress syndrome, adults, mechanical ventilation, guideline, end-expiratory pressure, tidal volume, inspiratory pressure, extracorporeal membrane oxygenation. \ua9 2018 National Research University Higher School of Economics. All rights reserved