Mechanical Ventilation In Adult Patients Research Articles

Prediction of ventilator weaning failure in postoperative cardiac surgery patients using vasoactive-ventilation-renal score and nomogram analysis.

This study evaluated the predictive value of the vasoactive-ventilation-renal (VVR) score in identifying the risk of weaning failure after cardiac surgery and developing a nomogram model to help physicians improve the success rate of weaning from mechanical ventilation in adult patients undergoing postoperative cardiac surgery. Clinical data were retrospectively collected from adult patients who underwent extracorporeal circulation cardiac surgery at the First Affiliated Hospital of Nanjing Medical University between August 2022 and April 2023 and who were subsequently transferred to the Intensive Care Unit (ICU) and treated with vasoactive drugs. Patients were divided into successful and unsuccessful weaning groups based on first-attempt weaning success. Variable selection was regularized using univariate logistic regression and Least absolute shrinkage and selection operator (LASSO) regularization. Multivariate logistic regression was performed to identify predictors and a nomogram was created to predict the risk of weaning failure. A total of 519 patients were included in the study. After selecting multiple stepwise variables, the VVR score before weaning, the modified Sequential Organ Failure Assessment (mSOFA) score on weaning day, and mechanical ventilation duration before weaning were determined as predictive indicators of weaning failure in adult patients after cardiac surgery. The optimal cut-off values for these indicators were 18.46 points, 4.33 points, and 20.50 h, respectively. The predictive model constructed using these three factors demonstrated good predictive performance. The VVR score before weaning accurately predicts the probability of weaning failure in adult patients after cardiac surgery. The weaning risk-predictive nomogram model, established based on the VVR score, mSOFA score, and mechanical ventilation duration before weaning, demonstrated robust predictive ability.

Interpretation of new concepts and approaches in the ESICM guidelines on acute respiratory distress syndrome: definition, phenotyping and respiratory support strategies

Acute respiratory distress syndrome (ARDS) continues to be one of the most life-threatening conditions for patients in the intensive care unit (ICU). The 2023 European Society of Intensive Care Medicine guidelines on ARDS: definition, phenotyping and respiratory support strategies (2023 Guideline) update the 2017 An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine clinical practice guideline: mechanical ventilation in adult patients with ARDS (2017 Guideline), including 7 aspects of 3 topics of definitions, phenotyping, and respiratory support strategies [including high flow nasal cannula oxygen (HFNO), non-invasive ventilation (NIV), neuromuscular blocking agents (NMBA), extracorporeal life support (ECLS), positive end-expiratory pressure (PEEP) with recruitment maneuvers (RM), tidal volume (VT), and prone positioning]. 2023 Guideline review and summarize the literature since the publication of the 2017 Guideline, covering ARDS and acute hypoxemic respiratory failure, as well as ARDS caused by novel coronavirus infection. Based on the most recent medical evidence, the 2023 Guideline provide clinicians with new ideas and approaches for nonpharmacologic respiratory support strategies for adults with ARDS. This article provides interpretation of the new concepts, the new approaches, the new recommended grading and new levels of evidence for ARDS in the 2023 Guideline.

The effect intraoperative positive end expiratory pressure and tidal volume on postoperative acute kidney injury after orthopedic surgery.

To test whether higher intraoperative PEEP levels and/or higher TV levels are associated with higher incidence of postoperative AKI within the first postoperative week, in adult patients having orthopedic surgeries under general anesthesia. We conducted a sub analysis of a non-randomized alternating intervention cross over study performed in patients undergoing orthopedic surgery under general anesthesia at Cleveland Clinic, Cleveland, OH. We included four different combinations of PEEP (5 or 8 cm H2 O) and TV (6 or 10 mL/kg of PBW) that alternated each week in the six orthopedic operating rooms. Our primary outcome was postoperative AKI defined by the KDIGO criteria with baseline creatinine as the closest preoperative value to the time of surgery obtained within 30 days and postoperative value as the highest creatinine value within 7 days after surgery. Secondary outcome was the maximum postoperative in-hospital creatinine level within seven postoperative days. A total of 1933 patients were included in the analysis. The incidence of AKI was 6.8% in the study population and similar in high TV versus low TV group and high PEEP versus low PEEP group. Neither TV nor PEEP significantly impacted AKI incidence. The estimated odds ratio of AKI comparing TV = 6 mL/kg to TV = 10 mL/kg was 0.96 (97.5% CI: 0.63, 1.46; p = .811); while the estimated odds ratio of AKI comparing PEEP = 5cm H2 O to PEEP = 8cm H2 O was 0.92 (97.5% CI: 0.60, 1.39; p = .623). No interaction was found between TV and PEEP on AKI. Additionally, neither TV nor PEEP had a significant effect on the seven postoperative day creatinine levels. Higher levels of PEEP or TV during mechanical ventilation in adult patients undergoing orthopedic surgeries under general anesthesia do not increase the odds of developing postoperative AKI within the narrow limits studied.

Cost-Utility Analysis of Home Mechanical Ventilation in Patients with Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis is a disease with rapid progression. The use of mechanical ventilation helps to manage symptoms and delays death. Use in a home environment could reduce costs and increase quality of life. The aim of this study is a cost–utility analysis of home mechanical ventilation in adult patients with amyotrophic lateral sclerosis from the perspective of healthcare payers in the Czech Republic. The study evaluates home mechanical ventilation (HMV) and mechanical ventilation (MV) in a healthcare facility. A Markov model was compiled for evaluation in a timeframe of 10 years. Model parameters were obtained from the literature and opinions of experts from companies dealing with home care and home mechanical ventilation. The cost–utility analysis was carried out at the end of the study and results are presented in incremental cost–utility ratio (ICUR) using quality-adjusted life-years. Uncertainty was assessed by one-way sensitivity analysis and scenario analysis. The cumulative costs of HMV are CZK 1,877,076 and the cumulative costs of the MV are CZK 7,386,629. The cumulative utilities of HMV are 12.57 quality-adjusted life year (QALY) and the cumulative utilities of MV are 11.32 QALY. The ICUR value is CZK-4,403,259. The results of this study suggest that HMV is cost effective.

Critically Ill Adults With Coronavirus Disease 2019 in New Orleans and Care With an Evidence-Based Protocol

BackgroundCharacteristics of critically ill adults with coronavirus disease 2019 (COVID-19) in an academic safety net hospital and the effect of evidence-based practices in these patients are unknown.Research QuestionWhat are the outcomes of critically ill adults with COVID-19 admitted to a network of hospitals in New Orleans, Louisiana, and what is an evidence-based protocol for care associated with improved outcomes?Study Design and MethodsIn this multi-center, retrospective, observational cohort study of ICUs in four hospitals in New Orleans, Louisiana, we collected data on adults admitted to an ICU and tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between March 9, 2020 and April 14, 2020. The exposure of interest was admission to an ICU that implemented an evidence-based protocol for COVID-19 care. The primary outcome was ventilator-free days.ResultsThe initial 147 patients admitted to any ICU and tested positive for SARS-CoV-2 constituted the cohort for this study. In the entire network, exposure to an evidence-based protocol was associated with more ventilator-free days (25 days; 0-28) compared with non-protocolized ICUs (0 days; 0-23, P = .005), including in adjusted analyses (P = .02). Twenty patients (37%) admitted to protocolized ICUs died compared with 51 (56%; P = .02) in non-protocolized ICUs. Among 82 patients admitted to the academic safety net hospital’s ICUs, the median number of ventilator-free days was 22 (interquartile range, 0-27) and mortality rate was 39%.InterpretationCare of critically ill COVID-19 patients with an evidence-based protocol is associated with increased time alive and free of invasive mechanical ventilation. In-hospital survival occurred in most critically ill adults with COVID-19 admitted to an academic safety net hospital’s ICUs despite a high rate of comorbidities.

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

Adopted from: Fan E., Del Sorbo L., Goligher E.C., Hodgson C.L., Munshi L., Walkey A.J., Adhikari N.K.J., Amato M.B.P., Branson R., Brower R.G., Ferguson N.D., Gajic O., Gattinoni L., Hess D., Mancebo J., Meade M.O., McAuley D.F., Pesenti A., Ranieri V.M., Rubenfeld G.D., Rubin E., Seckel M., Slutsky A.S., Talmor D., Thompson B. T., Wunsch H., Uleryk E., Brozek J., Brochard L.J. An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine Clinical Practice Guideline: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome. Am. J. Respir. Crit. Care Med. 2017; 195 (9): 1253–1263. DOI: 10.1164/rccm.201703-0548STThe 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 (4–8 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; a conditional recommendation has been developed for the use of higher positive end-expiratory pressure and recruitment maneuvers. CuОР – 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 coОР – 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.

Mechanical Ventilation in Adults with Acute Respiratory Distress Syndrome. Summary of the Experimental Evidence for the Clinical Practice Guideline.

The American Thoracic Society/European Society for Intensive Care Medicine/Society of Critical Care Medicine guidelines on mechanical ventilation in adult patients with acute respiratory distress syndrome (ARDS) provide treatment recommendations derived from a thorough analysis of the clinical evidence on six clinical interventions. However, each of the recommendations contains areas of uncertainty and controversy, which may affect their appropriate clinical application. To provide a critical review of the experimental evidence surrounding the pathophysiology of ventilator-induced lung injury and to help clinicians apply the clinical recommendations to individual patients. We conducted a literature search and narrative review. A large number of experimental studies have been performed with the aim of improving understanding of the pathophysiological effects of mechanical ventilation. These studies have formed the basis for the design of many clinical trials. Translational research has fundamentally advanced understanding of the mechanisms of ventilator-induced lung injury, thus informing the design of interventions that improve survival in patients with ARDS. Because daily management of patients with ARDS presents the challenge of competing considerations, clinicians should consider the mechanism of ventilator-induced lung injury, as well as the rationale for interventions designed to mitigate it, when applying evidence-based recommendations at the bedside.

Summary for Clinicians: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome Clinical Practice Guideline.

Summary for Clinicians: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome Clinical Practice Guideline.

The effect of high-flow nasal cannula in reducing the mortality and the rate of endotracheal intubation when used before mechanical ventilation compared with conventional oxygen therapy and noninvasive positive pressure ventilation. A systematic review and meta-analysis

BackgroundThe effects of high flow nasal cannula (HFNC) on adult patients when used before mechanical ventilation (MV) are unclear. We aimed to determine the effectiveness of HFNC when used before MV by comparison to conventional oxygen therapy (COT) and noninvasive positive pressure ventilation (NIPPV). MethodsThe Pubmed, Embase, Medline, Cochrane Central Register of Controlled Trials (CENTRAL) as well as the Information Sciences Institute (ISI) Web of Science were searched for all the controlled studies that compared HFNC with NIPPV and COT when used before MV in adult patients. The primary outcome was the rate of endotracheal intubation and the secondary outcomes were intensive care unit (ICU) mortality and length of ICU stay (ICU LOS). ResultsEight trials with a total of 1084 patients were pooled in our final studies. No significant heterogeneity was found in outcome measures. Compared both with COT and NIPPV, HFNC could reduce both of the rate of endotracheal intubation (OR 0.62, 95% CI 0.38–0.99, P=0.05; OR 0.48, 95% CI 0.31–0.73, P=0.0006) and ICU mortality (OR 0.47, 95% CI 0.24–0.93, P=0.03; OR 0.36, 95% CI 0.20–0.63, P=0.0004). As for the ICU LOS, we did not find any advantage of HFNC over COT or NIPPV. ConclusionsWhen used before MV, HFNC can improve the prognosis of patients compared both with the COT and NIPPV.

Official clinical practice guideline: Mechanical ventilation in adult patients with acute respiratory distress syndrome

Official clinical practice guideline: Mechanical ventilation in adult patients with acute respiratory distress syndrome

Erratum: An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine Clinical Practice Guideline: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome.

Erratum: An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine Clinical Practice Guideline: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome.

An Official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine Clinical Practice Guideline: Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome.

This document provides evidence-based clinical practice guidelines on the use of mechanical ventilation in adult patients with acute respiratory distress syndrome (ARDS). A multidisciplinary panel conducted systematic reviews and metaanalyses of the relevant research and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations. For all patients with ARDS, the recommendation is strong for mechanical ventilation using lower tidal volumes (4-8 ml/kg predicted body weight) and lower inspiratory pressures (plateau pressure < 30 cm H2O) (moderate confidence in effect estimates). For patients with severe ARDS, the recommendation is strong for prone positioning for more than 12 h/d (moderate confidence in effect estimates). For patients with moderate or severe ARDS, the recommendation is strong against routine use of high-frequency oscillatory ventilation (high confidence in effect estimates) and conditional for higher positive end-expiratory pressure (moderate confidence in effect estimates) and recruitment maneuvers (low confidence in effect estimates). Additional evidence is necessary to make a definitive recommendation for or against the use of extracorporeal membrane oxygenation in patients with severe ARDS. The panel formulated and provided the rationale for recommendations on selected ventilatory interventions for adult patients with ARDS. Clinicians managing patients with ARDS should personalize decisions for their patients, particularly regarding the conditional recommendations in this guideline.

Relationship of Steroid Dosing and Duration of Mechanical Ventilation in Adult Patients With Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Background: The optimal steroid dose for patients who require mechanical ventilation (MV) for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is unknown. Objective: The primary objective of the study is to describe the relationship between steroid doses prescribed and duration of MV. Methods: This was a retrospective study of patients admitted between October 2013 and September 2014 who were prescribed steroids and received MV for ≥48 hours for AECOPD. Results: Fifty-four patients were included in the study. Median maintenance daily dose of 300 mg/d (IQR: 150-300) prednisone equivalent was prescribed upon initiation of MV. The maintenance daily dose prescribed upon initiation of MV was visually plotted and was categorized into 2 groups: high dose (≥300 mg; n = 28) and low dose (<300 mg; n = 26). There was no relationship observed between the maintenance dose prescribed and duration of MV (P = .44) or intensive care unit (ICU) length of stay (LOS; P = .63). Seventeen (31.5%) patients developed an infection during their hospital stay. These patients received a higher cumulative dose of steroids compared to those without an infection (P = .035). Conclusion: No relationship was observed between maintenance steroid dose prescribed and the duration of MV or ICU LOS. Evaluation of a safe and effective dose and duration of steroids in this population is warranted.

Prediction equation to estimate dead space to tidal volume fraction correlates with mortality in critically ill patients

ObjectiveThe measurement of dead space to tidal volume fraction (Vd/Vt) using various methodologies has been shown to be a reliable predictor of mortality in critically ill patients. In this study, we evaluated the correlation of a validated equation using clinically available information to predict calculation of Vd/Vt with clinically relevant outcome parameters in patients requiring mechanical ventilation. MethodsCalculations of Vd/Vt were obtained based upon a previously published prediction equation for dead space ventilation fraction: Vd/Vt = 0.320 + 0.0106 (Paco2 − end-tidal carbon dioxide measurement) + 0.003 (respiratory rate per minute) + 0.0015 (age in years) on study days 1, 3 to 4, 6 to 9, and 14 after initiation of mechanical ventilation in adult patients who satisfied 1 of the 3 study defined diseases: (1) acute bacterial pneumonia, (2) acute respiratory distress syndrome, or (3) cystic fibrosis. ResultsUsing the final/last available time point calculation of Vd/Vt, a significant difference was observed between survivors and nonsurvivors both in relation to mean and median values (56.5% vs 71.2% and 56.0% vs 65.0%, respectively). In addition, sequential analyses of Vd/Vt calculations over time also demonstrated a statistically significant difference between survivors and nonsurvivors for days 6 to 9. ConclusionIn this study-specific population of critically ill patients, the prediction equation of Vd/Vt using clinically available parameters correlates with mortality. In addition, we provide a simple method to estimate Vd/Vt that can be potentially applicable to all critically ill intensive care unit patients.

Future studies should consider multiple predisposing conditions in predicting weaning failure from mechanical ventilation in patients after cardiac surgery

Dear Editor, We read the article titled “High levels of B-type natriuretic peptide (BNP) predict weaning failure from mechanical ventilation in adult patients after cardiac surgery” by Thiago Martins Lara et al. with interest (1). The authors aimed to evaluate whether serum levels of B-type natriuretic peptide are a predictor of weaning failure from mechanical ventilation after cardiac surgery. They concluded that high BNP levels are predictive of failure to wean from mechanical ventilation after cardiac surgery. Plasma levels of BNP are increased in disorders associated with intravascular volume overload, increased central venous pressure and left ventricular dysfunction. BNP secretion is directly proportional to left ventricular wall stress and blood volume. Because of these associations, there has been much interest in using BNP as a biomarker for heart failure (2). However, high levels of BNP are present in many cases for reasons unrelated to cardiac diseases. In several studies, BNP levels were higher in women than in men, independent of age. Although the reason for this difference is unknown, it is believed that estrogen may play a role. Furthermore, levels of BNP increase with age, and this difference is not associated with “age-related” diastolic dysfunction in either sex (3). Obese individuals have low circulating natriuretic peptide levels, and diabetes mellitus is also associated with low plasma levels of natriuretic peptide (4). In addition, elevated BNP levels may be observed in many diseases associated with hypervolemia, such as chronic renal failure, chronic liver disease and hyperaldosteronism (5). Furthermore, respiratory conditions, such as pulmonary embolism and chronic obstructive pulmonary disease, are associated with high levels of BNP in the absence of left heart failure. One of the most important conditions associated with elevated BNP levels is sepsis. Many studies have shown significantly higher BNP levels in patients with sepsis, and this effect was not related to myocardial dysfunction (6). In conclusion, high levels of BNP are presented as a predictive factor for failure to wean from mechanical ventilation after cardiac surgery in the study by Thiago Martins Lara et al. However, because BNP levels may be affected by many factors, the significance of those risk factors in weaning from mechanical ventilation after cardiac surgery should be considered in future large-scale prospective randomized clinical trials.

High levels of B-type natriuretic peptide predict weaning failure from mechanical ventilation in adult patients after cardiac surgery

OBJECTIVE:The failure to wean from mechanical ventilation is related to worse outcomes after cardiac surgery. The aim of this study was to evaluate whether the serum level of B-type natriuretic peptide is a predictor of weaning failure from mechanical ventilation after cardiac surgery.METHODS:We conducted a prospective, observational cohort study of 101 patients who underwent on-pump coronary artery bypass grafting. B-type natriuretic peptide was measured postoperatively after intensive care unit admission and at the end of a 60-min spontaneous breathing test. The demographic data, hemodynamic and respiratory parameters, fluid balance, need for vasopressor or inotropic support, and length of the intensive care unit and hospital stays were recorded. Weaning failure was considered as either the inability to sustain spontaneous breathing after 60 min or the need for reintubation within 48 h.RESULTS:Of the 101 patients studied, 12 patients failed the weaning trial. There were no differences between the groups in the baseline or intraoperative characteristics, including left ventricular function, EuroSCORE and lengths of the cardiac procedure and cardiopulmonary bypass. The B-type natriuretic peptide levels were significantly higher at intensive care unit admission and at the end of the breathing test in the patients with weaning failure compared with the patients who were successfully weaned. In a multivariate model, a high B-type natriuretic peptide level at the end of a spontaneous breathing trial was the only independent predictor of weaning failure from mechanical ventilation.CONCLUSIONS:A high B-type natriuretic peptide level is a predictive factor for the failure to wean from mechanical ventilation after cardiac surgery. These findings suggest that optimizing ventricular function should be a goal during the perioperative period.

Assessment of risk factors responsible for difficult weaning from mechanical ventilation in adults

ObjectiveThe aim of this work is to identify the most important risk factors responsible for difficult weaning from mechanical ventilation in adult patients. DesignA prospective cohort study. SettingRespiratory Intensive care unit of Alexandria main University Hospitals. PatientsThirty one patients requiring mechanical ventilation with difficult weaning according to Brochard’s classification. MethodsAfter failure of weaning on PSV mode of mechanical ventilation, the patient is reevaluated to detect the risk factors responsible for difficult weaning. ResultsEighteen patients (58%) were successfully weaned and thirteen (42%) failed weaning trials and finally died. Of the thirty-one studied cases, 16 (52%) were males. Mean age of the studied patients was 57.7±15 and mean BMI was 30±7.9. Twenty-one patients (67.7%) required prolonged mechanical ventilation and ten (32%) required less than 14days. Mean of Rapid Shallow Breathing Index measured during SBT was 56±9breaths/min per L among cases who were successfully weaned from MV and 122±19breaths/min per L among those who failed weaning trials. Mean CROP index value was 38.7±11ml/breath per min among cases who were successfully weaned and of significantly lower value 7.5±2.6ml/breath per min among those who failed weaning trials & finally died, (p=0.00). In the present work; risk factors that found to be responsible for failure of weaning trials were recent infections (pulmonary and/or extra-pulmonary) that were detected in all the studied cases (100%), disturbances in the trace elements & electrolytes in 26 cases (83.8%), cardiovascular dysfunctions in 18 (58%), psychological problems in 12 (38.7%), endocrinal disturbances in the form of hypothyroidism in 3 (9.6%), nutritional deficiency in 27 (87%), neuromuscular dysfunctions in 14 (45%) and other additional co-morbid problems as hepatic or renal impairment in 15 patients (48%). In the present work; EMG & nerve conduction study was done to 19 cases with difficult weaning. The results showed 26% with normal picture, 63% with moderate to severe axonal sensory motor peripheral neuropathy and 10.5% with a picture of myopathy. Regarding the effect of neuromuscular dysfunctions on the outcome of MV, in the present study, 33% of the patients with polyneuropathy failed weaning trials and finally died (p=0.798). The present study stresses on the importance of neuromuscular assessment in all cases with difficult weaning as this may be an important contributing factor for difficult weaning and prolonged mechanical ventilation. ConclusionAll potential causes of ventilator dependency should be identified when a patient is difficult-to-wean. Then, a plan should be developed that uses a multidisciplinary team approach to correct the reversible causes of weaning failure and facilitates weaning thereafter.

High levels of B-type natriuretic peptide predict weaning failure from mechanical ventilation in adult patients after cardiac surgery

Failure to wean from mechanical ventilation is related to worse outcomes after cardiac surgery. The aim of the study was to evaluate B-type natriuretic peptide (BNP) as a predictor factor of failure to wean from mechanical ventilation after cardiac surgery.

Benefits and Risks Associated with the R100 High Frequency Oscillatory Ventilator for Patients with Severe Hypoxaemic Respiratory Failure

High frequency oscillatory ventilation has been shown to improve oxygenation of patients with severe respiratory failure. This prospective study examined the potential benefits and risks of the latest generation high frequency oscillatory ventilator (R100, Metran, Saitama, Japan), initiated when the target oxygenation could not be achieved by conventional mechanical ventilation in adult patients with severe hypoxaemic respiratory failure. Thirty-six patients with severe respiratory failure treated with the R100 high frequency oscillatory ventilator were considered. Pneumonia and exacerbation of interstitial pneumonia were the main causes of respiratory failure. The median time on conventional mechanical ventilation or airway pressure release ventilation prior to high frequency oscillatory ventilation was 9.3 hours (interquartile range 4.8 to 25). PaO2/FiO2 at 24 hours after initiation of high frequency oscillatory ventilation was significantly better than the PaO2/FiO2 at baseline (151.2 +/- 61.2 vs. 99.5 +/- 50.0, P = 0.0001). Refractory hypoxaemia within 24 hours was associated with a high risk of mortality (P = 0.0092) and 23 patients (64%), including 11 patients with exacerbation of interstitial pneumonia, died by 30 days. Of the 36 patients included in the study (including one who had developed pneumothorax before high frequency oscillatory ventilation), 12 (33%) developed barotrauma during the course of their intensive care unit stay. In the multivariate analysis, only exacerbation of interstitial pneumonia was a significant risk factor for barotrauma. In summary, the latest generation high frequency oscillatory ventilator could improve oxygenation in adult patients with life-threatening hypoxaemic respiratory failure but the incidence of barotrauma was substantial.

Mechanical ventilation in adults who need respiratory assistance

In the care of postoperative, acutely ill, or traumatically injured patients, hypoxemia and acute respiratory acidosis are commonly encountered life-threatening conditions that require intervention, often via mechanical ventilation. Knowing the indications for initiation of mechanical ventilation in adult patients, the various modes available, and the protocols for weaning and liberation will enable PAs to appropriately evaluate and treat these patients.