How to measure respiratory mechanics during controlled mechanical ventilation

Bedside measurement of respiratory mechanics allows to closely monitor the lung function in critically ill patients. The two fundamental parameters describing the respiratory system mechanics are resistance and compliance. Resistance of the respiratory system describes the opposition to gas flow during inspiration. During volume-controlled ventilation, resistance can be calculated as the ratio between the peak to plateau pressure drop and the resulting flow rate. Compliance describes the elastic property of the respiratory system, comprising the lung and the chest wall. It is the ratio between a change in volume (i.e. tidal volume) and the corresponding change in pressure, calculated as the difference between plateau pressure and total positive end-expiratory pressure, measured by end-inspiratory and end-expiratory manual occlusion, respectively. In this review, we describe how to measure respiratory mechanics at the bedside, starting from the physiological background of the equation of motion of the respiratory system. (Intensive care

Plateau Pressure during Pressure Control Ventilation

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Extubation Failure After Successful Spontaneous Breathing Trial: Prediction Is Still a Challenge!

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How to insert a PICC: practical tips for the intensive care physician

Peripherally inserted central catheters (PICCs) are central vascular access devices inserted via deep veins of the arm, also useful in critical care settings. The purpose of this article is to offer to a critical care clinician with good skills in central venous catheterization, but who has limited experience on PICC catheters, the basic information on how the procedure is performed and how to minimize the risks of complications or failure of the maneuver. The main technical steps and the main precautions to be taken during PICC placement will be analyzed, with reference to the differences compared to central catheterization. Specifically, the pre-procedural phase and the intraprocedural main steps of the maneuver will be analyzed. A dedicated Vascular Access Team is considered useful and desirable by the current literature, but when the use of the PICC proves useful or even mandatory, the intensive care physician skilled in central venous catheters can transfer skills from central to peripheral catheterization

Epidemiology and patterns of tracheostomy practice in patients with acute respiratory distress syndrome in ICUs across 50 countries

BackgroundTo better understand the epidemiology and patterns of tracheostomy practice for patients with acute respiratory distress syndrome (ARDS), we investigated the current usage of tracheostomy in patients with ARDS recruited into the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG-SAFE) study.MethodsThis is a secondary analysis of LUNG-SAFE, an international, multicenter, prospective cohort study of patients receiving invasive or noninvasive ventilation in 50 countries spanning 5 continents. The study was carried out over 4 weeks consecutively in the winter of 2014, and 459 ICUs participated. We evaluated the clinical characteristics, management and outcomes of patients that received tracheostomy, in the cohort of patients that developed ARDS on day 1–2 of acute hypoxemic respiratory failure, and in a subsequent propensity-matched cohort.ResultsOf the 2377 patients with ARDS that fulfilled the inclusion criteria, 309 (13.0%) underwent tracheostomy during their ICU stay. Patients from high-income European countries (n = 198/1263) more frequently underwent tracheostomy compared to patients from non-European high-income countries (n = 63/649) or patients from middle-income countries (n = 48/465). Only 86/309 (27.8%) underwent tracheostomy on or before day 7, while the median timing of tracheostomy was 14 (Q1–Q3, 7–21) days after onset of ARDS. In the subsample matched by propensity score, ICU and hospital stay were longer in patients with tracheostomy. While patients with tracheostomy had the highest survival probability, there was no difference in 60-day or 90-day mortality in either the patient subgroup that survived for at least 5 days in ICU, or in the propensity-matched subsample.ConclusionsMost patients that receive tracheostomy do so after the first week of critical illness. Tracheostomy may prolong patient survival but does not reduce 60-day or 90-day mortality

Patterns of use of adjunctive therapies in patients with early moderate- severe Acute Respiratory Distress syndrome: Insights from the LUNG SAFE Study

Background: Adjunctive strategies are an important part of the management of ARDS. However, their application in clinical practice remains inconsistent. Research Question: We wished to determine the frequency and patterns of use of adjunctive strategies in patients with moderate to severe ARDS (PaO2/FIO2 [P/F ratio] < 150) enrolled into the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Study Design and Methods: The LUNG SAFE study was an international, multicenter, prospective cohort study of patients with severe respiratory failure, conducted in 2014 in 459 ICUs from 50 countries. The primary objective of this substudy was to determine the frequency of use of widely available (neuromuscular blockade, prone position) adjuncts vs adjuncts requiring specialized equipment (extracorporeal membrane oxygenation, inhaled vasodilators, high-frequency ventilation) in patients in the first 48 h of moderate to severe ARDS (P/F ratio < 150). Results: Of 1,146 patients on invasive ventilation with moderate to severe ARDS, 811 patients (71%) received no adjunct within 48 h of ARDS onset. Of 335 (29%) that received adjunctive strategies, 252 (75%) received a single strategy, and 83 (25%) receiving more than one adjunct. Of ARDS nonsurvivors, 67% did not receive any adjunctive strategy in the first 48 h. Most patients (67%) receiving specialized adjuncts did not receive prone positioning or neuromuscular blockade. Patients that received adjuncts were more likely to have their ARDS recognized, be younger and sicker, have pneumonia, be more difficult to ventilate, and be in a European high-income country than those that did not receive adjuncts. Interpretation: Three in 10 patients with moderate to severe ARDS, and only one-third of nonsurvivors, received adjunctive strategies over the first 48 h of ARDS. A more consistent and evidence-driven approach to adjunct use may reduce costs and improve outcomes in patients with moderate to severe ARDS. Trial Registry: ClinicalTrials.gov; No.: NCT02010073; URL: www.clinicaltrials.go