Forms Of Acute Respiratory Failure Research Articles

Development of a Lung Rescue Team to Improve Care of Subjects With Refractory Acute Respiratory Failure.

A lung-protective mechanical ventilation strategy has become the hallmark of ventilation management for patients with acute respiratory failure. However, some patients progress to more severe forms of acute respiratory failure with refractory hypoxemia. In such circumstances, individualized titration of mechanical ventilation according to the patient's specific respiratory and cardiovascular pathophysiology is desirable. A lung rescue team (LRT) was recently established at our institution to improve the medical care of patients with acute respiratory failure when conventional treatment fails. The aim of this report is to describe the consultation processes, the cardiopulmonary assessment, and the procedures of the LRT. This was a retrospective review of the LRT management of patients with acute respiratory failure and refractory hypoxemia at Massachusetts General Hospital in Boston, Massachusetts. The LRT is composed of a critical care physician, the ICU respiratory therapist on duty, the ICU nurse on duty, and 2 critical care fellows. In the LRT approach, respiratory mechanics are evaluated through lung recruitment maneuvers and decremental PEEP trials by means of 3 tools: esophageal manometry, echocardiography, and electrical impedance tomography lung imaging. The LRT was consulted 89 times from 2014 to 2019 for evaluation and management of severely critically ill patients with acute respiratory failure and refractory hypoxemia on mechanical ventilation. The LRT was requested a median of 2 (interquartile range 1-6) d after intubation to optimize mechanical ventilation and to titrate PEEP in 77 (86%) subjects, to manage ventilation in 8 (9%) subjects on extracorporeal membrane oxygenation (ECMO), and to manage weaning strategy from mechanical ventilation in 4 (5%) subjects. The LRT found consolidations with atelectasis responsive to recruitment maneuvers in 79% (n = 70) of consultations. The LRT findings translated into a change of care in 81% (n = 72) of subjects. The LRT individualized the management of severe acute respiratory failure. The LRT consultations were shown to be effective, safe, and efficient, with an impact on decision-making in the ICU.

\u201cI had the feeling that I was trapped\u201d: a bedside qualitative study of cognitive and affective attitudes toward noninvasive ventilation in patients with acute respiratory failure

BackgroundNoninvasive ventilation (NIV) is the application of mechanical ventilation through a mask. It is used to treat certain forms of acute respiratory failure in intensive care units (ICU). NIV has clinical benefits but can be anxiogenic for the patients. This study aimed at describing cognitive and affective attitudes toward NIV among patients experiencing NIV for the first time in the context of an ICU stay.MethodsSemi-structured interviews were conducted in 10 patients during their ICU stay and soon after their first NIV experience. None of the patients had ever received NIV previously. Evaluative assertion analysis and thematic analysis were used to investigate cognitive and affective attitudes toward NIV before, during, and after the first NIV experience, as well as patient attitudes toward caregivers and relatives.ResultsBefore their first NIV session, the cognitive attitudes of the patients were generally positive. They became less so and more ambiguous during and after NIV, as the patients discovered the actual barriers associated with NIV. Affective attitudes during NIV were more negative than affective attitudes before and after NIV, with reports of dyspnea, anxiety, fear, claustrophobic feelings, and reactivation of past traumatic experiences. The patients had more positive attitudes toward the presence of a caregiver during NIV, compared to the presence of a family member.ConclusionThis study corroborates the possibly negative—or even traumatic—nature of the NIV experience, with emphasis on the role of affective attitudes. This is a rationale for evaluating the impact of NIV-targeted psychological interventions in ICU patients with acute respiratory failure.

Heart-lung interactions in acute respiratory distress syndrome: pathophysiology, detection and management strategies.

Acute respiratory distress syndrome (ARDS) is the most severe form of acute respiratory failure characterized by diffuse alveolar and endothelial damage. The severe pathophysiological changes in lung parenchyma and pulmonary circulation together with the effects of positive pressure ventilation profoundly affect heart lung interactions in ARDS. The term pulmonary vascular dysfunction (PVD) refers to the specific involvement of the vascular compartment in ARDS and is expressed clinically by an increase in pulmonary arterial (PA) pressure and pulmonary vascular resistance both affecting right ventricular (RV) afterload. When severe, PVD can lead to RV failure which is associated to an increased mortality. The effect of PVD on RV function is not only a consequence of increased pulmonary vascular resistance as afterload is a much more complex phenomenon that includes all factors that oppose efficient ventricular ejection. Impaired pulmonary vascular mechanics including increased arterial elastance and augmented wave-reflection phenomena are commonly seen in ARDS and can additionally affect RV afterload. The use of selective pulmonary vasodilators and lung protective mechanical ventilation strategies are therapeutic interventions that can ameliorate PVD. Prone positioning and the open lung approach (OLA) are especially attractive strategies to improve PVD due to their effects on increasing functional lung volume. In this review we will describe some pathophysiological aspects of heart-lung interactions during the ventilatory support of ARDS, its clinical assessment and discuss therapeutic interventions to prevent the occurrence and progression of PVD and RV failure.

СУЧАСНІ ШЛЯХИ ВВЕДЕННЯ ЛІКАРСЬКИХ ПРЕПАРАТІВ ПРИ ВИКОНАННІ СЕРЦЕВО-ЛЕГЕНЕВОЇ ТА МОЗКОВОЇ РЕАНІМАЦІЇ НА ДОГОСПІТАЛЬНОМУ ЕТАПІ

Виконання базових алгоритмів сучасного клінічного протоколу раптової зупинки кровообігу (РЗК), вимагає, зокрема, якнайшвидшого забезпечення венозного доступу. Водночас, саме відсутність кровообігу є тим несприятливим фактором, який суттєво ускладнює, а, нерідко, унеможливлює успішну реалізацію цієї методики, ламаючи при цьому всі ланки серцево-легеневої та мозкової реанімації, відповідно, зводячи її ефективність до фатального мінімуму. Такі випадки, зокрема, спостерігаються у пацієнтів із РЗК на тлі гіповолемії тяжкого ступеня, гіпоксії, у наркоманів тощо.Мета – дослідити та проаналізувати альтернативні внутрішньовенному шляхи введення медикаментів при раптовій зупинці кровообігу за умов діяльності бригади екстреної (швидкої) медичної допомоги.Матеріали і методи. Проведено детальний аналіз альтернативних методик внутрішньовенному способів введення лікарських засобів, їх порівняльну характеристику, оцінено переваги та недоліки, зважаючи при цьому на їх практичну доступність, вартість, адаптацію до вікової характеристики постраждалих, які перебувають в стані клінічної смерті. Використовуючи бібліосемантичний, аналітичний методи та метод системного аналізу, проведено ???Результати. Після проведення детального аналізу методик та шляхів введення медикаментів при раптовій зупинці кровообігу лікарями екстреної (швидкої) медичної допомоги (Е(Ш)МД), зважаючи на важкість, а подекуди неможливість забезпечення внутрішньовенного доступу, слід вважати внутрішньо-кістковий доступ найбільш ефективним засобом введення медикаментів під час виконання реанімаційних заходів. Наступним за ефективністю, складністю проведення, особливо за умов масового випадку після викоричтання класичного внутріщньовенного доступу, є внутрішньокістковий доступ.На сьогоднішні цей спосіб вважається хорошою альтернативою іншим методам, оскільки при дотриманні нескладних технічних вимог досягається терапевтичний ефект від введених медикаментів, аналогічний тому, що й при внутрішньовенних інфузіях.Основною перевагою внутрішньокісткового доступу, порівняно з досліджуваними (ендотрахеальний, внутрішньосерцевий, внутрішньоартеріальний), складними за технікою виконання, які загрожують розвитком значних ускладнень, є можливість його застосування у немовлят та дітей молодшого віку, знайти вену в яких, як правило, достатньо важко. Також даний спосіб вважається хорошою альтернативою іншим методикам, тому що за дотримання нескладних технічних вимог при цьому досягається якісний терапевтичний ефект від введених медикаментів.Висновки. Якісна теоретична підготовка, наявність необхідного сучасного медичного спорядження, практичне професійне освоєння стандартних і сучасних альтернативних методик донесення медикаментів при раптовій зупинці кровообігу лікарями Е(Ш)МД сприятимуть дотриманню основних положень клінічних протоколів лікування даного термінального стану, а в кінцевому результаті приведуть до зниження догоспітальної та ранньої госпітальної летальності.

Effect of prenatal steroidal inhibition of sPLA2 in a rat model of preterm lung

IntroductionSecretory phospholipase A2 regulates surfactant catabolism and inflammatory cascade. This enzyme is correlated with compliance, oxygenation and major outcomes in various forms of acute respiratory failure. Steroids inhibit secretory phospholipase A2 in cell culture and are widely used to boost surfactant production before preterm delivery. No data are available about the effect of antenatal steroids on secretory phospholipase A2 in the offspring: we aimed to study this effect in a rat model of preterm lung. Material and methodsFifteen pregnant Wistar rats were randomized to receive betamethasone, dexamethasone or placebo at 20 and 21 days gestation. Newborn rats were supported for 8 h and then sacrificed: lung tissue was analysed for secretory phospholipase A2 expression and activity, inflammatory mediators and protein content. Lipidomics was analysed using liquid chromatography-mass spectrometry. ResultsSecretory phospholipase A2 expression was significantly reduced by antenatal steroids (p < 0.001). Secretory phospholipase A2 activity, TNFα and lysophosphatidylethanolamine, a product of phospholipase reaction, were lowest in betamethasone-treated rats (p < 0.001). There was a strong correlation between secretory phospholipase A2 activity and lysophosphatidylethanolamine (r = 0.75; p = 0.001) and this remained significant after adjustment for total proteins or phospholipids. ConclusionsAntenatal steroids decrease secretory phospholipase A2 in rat model of preterm lung.

A numerical model of blood oxygenation during veno-venous ECMO: analysis of the interplay between blood oxygenation and its delivery parameters.

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is an important tool in the management of most severe forms of acute respiratory failure. The determinants and management of oxygen delivery in patients treated with VV-ECMO is a complex topic. The physiological principles of oxygenation on VV-ECMO are reviewed in many textbooks. However a numerical model is an additional instrument to be used in understanding and exploring this intricate subject matter. We present a numerical model of blood oxygenation during VV-ECMO. Using this model we examined the role and impact of each determinant on blood oxygenation. The numerical analysis of variation and interplay between each oxygenation determinants during VV-ECMO is presented in graphical form. These results corroborate all the findings of previous studies. The proposed numerical model facilitates understanding of oxygenation physiology during VV-ECMO; it can be used for a medical simulation system and for teaching the principles of oxygenation during VV-ECMO.

Is the gastric tube a burden for the noninvasive ventilation?

The application of noninvasive ventilation (NIV) in ICUs has spread widely during the years. It is used in the treatment of different forms of acute respiratory failure and COPD exacerbations. Although NIV is thought to be more comfortable for patients than invasive mechanical ventilation, its failure rates in the ICUs range between 10 and 40%. Except for the interface-related problems, there are some specific considerations for the patient-ventilator interaction and the applied mechanical forces. During NIV there is a predisposition for the stomach to be inflated with gas, which could cause severe respiratory complications, especially in COPD patients, and thus prolong the mechanical ventilation and the weaning process. This remains one of the major causes for NIV failure. Although a lot of face masks with different interfaces are available on the market, just a few have additional ports for a NGT. They are characterized by higher price and a complex setup. In order to perform NIV in patients, requiring NGT placement, without additional air leaks and to be able to ensure their enteral nutrition and/or stomach drainage, we installed a port for a NGT on a standard face mask.

ABSTRACT 419

Background and aims: Acute respiratory distress syndrome (ARDS) is the most severe form of acute respiratory failure both in adult and children characterized by increased capillary permeability, inflammation and alveolar repair. Both Consensus Conference performed in 1994 and 2011 require the presence of bilateral pulmonary infiltrates on chest X-ray (CXR). To be consistently useful, interpretation of the CXR must be reliable. Adult studies on radiographic interpretation in ARDS have shown limited inter-observer agreement and concluded that intensivists without formal consensus training can only achieve moderate level of agreements. Aims: A computer-aided diagnosis system (CAD) was developed to automatically detect ARDS. The system is based on texture analysis of many patch of parenchyma lung among the four quadrants. The aim of the present study is to compare clinical assessment to the CAD system. Methods: CXR database was done using 111 CXR selected among 843 children included in a previous study, 60/111 CXR presented an ARDS based on gold standard reading. CXR reading was first performed by two intensivists. In case of disagreement, a consensus was performed with a third intensivist. The 111 CXR were diagnosed automatically by our CAD system. Results: Inter-observer variability was fund between the first two intensivists with a moderate kappa (kappa=0.55). The CAD system was able to significantly improve the kappa (kappa=0.75). Specificity and sensibility of the CAD system was 84.4 and 90% respectively. Conclusions: Our study confirms the inter-observer variability with clinical assessment and the use of a CAD system for CXR interpretation in ARDS is able to reduce it.

Extracorporeal lung support for COPD reaches a crossroad

The natural course of chronic obstructive pulmonary disease usually evolves into a form of acute respiratory failure characterised by alveolar hypoventilation and severe respiratory acidosis. As the severity and frequency of hypercapnic respiratory failure increases, the negative evolution of the syndrome progresses. Non-invasive mechanical ventilation delays fatal evolution through restoration of sufficient alveolar ventilation.1 Unfortunately, such ventilation can fail in up to 40% of the most severe cases and patients then have to undergo invasive ventilation to restore gas exchange.

Implementierung der S3-Leitlinie zur nicht-invasiven Beatmung bei akuter respiratorischer Insuffizienz im klinischen Alltag

Application of non-invasive ventilation (NIV) in acute respiratory failure (ARF) since publication of the German S3 guideline in 2008. A questionnaire was sent to 145 regional hospitals representing 99 ICUs, asking for: responsibility for NIV, number of ICU-beds, awareness of the guideline and the detailed recommendations, its implementation, use of ventilators and interfaces, location of NIV application. The response rate in relation to hospitals was 43.5%, 63 questionnaires were sent back (30 by internists, 33 by anesthesiologists). 97% of the participants reported to know the guideline; 20 (67%) of the internists and 16 (48,5%) of the anaesthesiologists who answered are aware of the detailed recommendations. 40 of 63 departments (63,5%) reported an increase of NIV since publication of the guideline. 22 of 33 (66%) anaesthesiologists and 18 of 30 (60%) internists reported to apply NIV in all forms of ARF. The others reported a differentiated application, mainly in pulmonary edema and hypercapnic respiratory failure, whereas NIV was rarely used in non-cardiac hypoxemic ARF. 92% of the participants used the guideline in decision-finding for NIV. Their decision was additionally influenced by clinical experience. In all clinics NIV took place on the ICU; furthermore in 6 medical clinics on specialized respiratory units. Mainly ICU-ventilators with NIV mode were used; 38% of the ICUs only held this type of ventilator. In 84 % full-face masks were preferred; 71% of the users only used a single type of mask. The S3 guideline for NIV in ARF is well-known in intensive care in Germany, but not all are aware of the detailed re-commendations. The use of NIV in ARF has increased since publication of the guideline but nearly always follows additional clinical assessment in decision-making. In one third it is restricted to special indications, with very limited application in non-cardiac hypoxemic ARF. Full-face masks are preferred according to the guideline. All ICUs, that participated in the survey, hold ventilators for NIV.

Clinical review: Helmet and non-invasive mechanical ventilation in critically ill patients

Non-invasive mechanical ventilation (NIV) has proved to be an excellent technique in selected critically ill patients with different forms of acute respiratory failure. However, NIV can fail on account of the severity of the disease and technical problems, particularly at the interface. The helmet could be an alternative interface compared to face mask to improve NIV success. We performed a clinical review to investigate the main physiological and clinical studies assessing the efficacy and related issues of NIV delivered with a helmet. A computerized search strategy of MEDLINE/PubMed (January 2000 to May 2012) and EMBASE (January 2000 to May 2012) was conducted limiting the search to retrospective, prospective, nonrandomized and randomized trials. We analyzed 152 studies from which 33 were selected, 12 physiological and 21 clinical (879 patients). The physiological studies showed that NIV with helmet could predispose to CO2 rebreathing and increase the patients' ventilator asynchrony. The main indications for NIV were acute cardiogenic pulmonary edema, hypoxemic acute respiratory failure (community-acquired pneumonia, postoperative and immunocompromised patients) and hypercapnic acute respiratory failure. In 9 of the 21 studies the helmet was compared to a face mask during either continous positive airway pressure or pressure support ventilation. In eight studies oxygenation was similar in the two groups, while the intubation rate was similar in four and lower in three studies for the helmet group compared to face mask group. The outcome was similar in six studies. The tolerance was better with the helmet in six of the studies. Although these data are limited, NIV delivered by helmet could be a safe alternative to the face mask in patients with acute respiratory failure.

Predictive value of daily living score in acute respiratory failure of COPD patients requiring invasive mechanical ventilation pilot study.

BackgroundMechanical ventilation (MV) is imperative in many forms of acute respiratory failure (ARF) in COPD patients. Previous studies have shown the difficulty to identify parameters predicting the outcome of COPD patients treated by invasive MV. Our hypothesis was that a non specialized score as the activities daily living (ADL) score may help to predict the outcome of these patients.MethodsWe studied the outcome of 25 COPD patients admitted to the intensive care unit for ARF requiring invasive MV. The patients were divided into those weaning success (group A n = 17, 68%) or failure (group B n = 8, 32%). We investigated the correlation between the ADL score and the outcome and mortality.ResultsThe ADL score was higher in group A (5.1 ±1.1 vs 3.7 ± 0.7 in group B, p < 0.01). Weaning was achieved in 76.5% of the cases with an ADL score ≥ 4 and in 23.5% of the cases with an ADL score < 4 (p < 0.05). Pulmonary function test, arterial blood gases collected during period of clinical stability and at admission and nutritional status were similar in both groups. The mortality, at six months, was 36%. The ADL score was a significant predictor of 6-month mortality (80 with an ADL score <4, 20 with an ADL score ≥4, p < 0.01).ConclusionOur pilot study demonstrates that the ADL score is predictive of weaning success and mortality at 6 months, suggesting that the assessment of daily activities should be an important component of ARF management in COPD patients.

Noninvasive ventilation for acute respiratory failure: a review of the literature and current guidelines

Noninvasive ventilation, both continuous positive airway pressure and noninvasive positive pressure ventilation, has been used increasingly for acute respiratory failure over the past several years. Noninvasive ventilation has been proven to be beneficial for some causes of acute respiratory failure, most clearly for acute exacerbations of chronic obstructive pulmonary disease, while its use in other forms of acute respiratory failure remains more controversial. In this article, the evidence for the use of noninvasive ventilation in various kinds of acute respiratory failure will be examined. Particular attention will be paid to the clinical situations commonly encountered by emergency medicine and general internal medicine clinicians. The potential dangers of noninvasive ventilation as well as some guidelines for clinical decision making when treating patients with this mode of ventilator support will also be discussed.

Lungenprotektive Beatmung bei ARDS

Mechanical ventilation (MV) is one of the most essential cornerstones of intensive care therapy. Although of pivotal importance for many patients suffering from respiratory insufficiency MV itself may further induce pathophysiological processes due to the mechanical stress exerted on the lungs. Particularly during one of the most distinctive forms of acute respiratory failure, acute respiratory distress syndrome (ARDS), a tremendous impairment of the lungs occurs characterized by heterogeneous damage where normally aerated areas coexist with consolidated and collapsed areas. Although MV is necessary for the treatment of severe hypoxemia it causes damage not only in the lungs but also in other organs due to a secondary inflammatory process in the lungs. To reduce these reactions an evidence-based concept of lung protective ventilation is essential.

Pulmonologists and intensivists: “two hearts are better than one”

The Respiratory Intensive Care Assembly at the European Respiratory Society (ERS) is composed of two areas of interest: noninvasive ventilation and acute critical care. Both of them are mainly focused on respiratory issues related to critically ill patients, aiming to promote the exchange of information between pneumonologists and intensivists, and to foster and encourage education, research and scientific progress. When the Respiratory Intensive Care Assembly became part of the ERS, one of the groups was named “noninvasive ventilatory support” making it a unique feature within the society, since the name of a technique was chosen as representative of a group. Why did this happen? The spread of innovation in medicine has a typical behaviour, in which the so-called innovators propose new technologies, diagnostic strategies or other elements of care, which are not necessarily followed by an immediate clinical application, despite the excellent results 1. The time lag encompassing the dissemination of innovation and its spread in “real life” varies largely. At the beginning of the 1990s, a group of enthusiastic people, mainly based in Europe 2–4 or in a specific area of the USA 5, “re-discovered” a technique that was first employed in the 1930s by a genuine pioneer, Emerson 6, and then was abandoned for decades. This technique is called noninvasive positive pressure ventilation (NIV), and few individuals though that, less than 20 yrs later, NIV would have became a first-line intervention for certain forms of acute respiratory failure (ARF), such as chronic obstructive pulmonary disease (COPD) exacerbations 7, 8. Nowadays the real life use of NIV has increased so much in the intensive care unit (ICU), respiratory ICU (RICU), emergency room, or even medical ward, that at least in certain countries, such as France, >50% of patients starting mechanical ventilation in …

Factors predicting successful noninvasive ventilation in acute lung injury

Noninvasive ventilation (NIV) has been successfully used to treat various forms of acute respiratory failure. It remains unclear whether NIV has potential as an effective therapeutic method in patients with acute lung injury (ALI). The aims of this study were to determine factors predicting the need for endotracheal intubation in ALI patients treated with NIV, and to promote the selection of patients suitable for NIV. We conducted a retrospective study of all patients admitted to the intensive care unit (ICU) of the Nippon Medical School Hospital from 2000 to 2006 with a diagnosis of ALI, in whom NIV was initiated. A total of 47 patients with ALI received NIV, and 33 patients (70%) successfully avoided endotracheal intubation. Patients who required endotracheal intubation had a significantly higher Acute Physiology and Chronic Health Evaluation (APACHE) II score and a significantly higher Simplified Acute Physiology Score (SAPS) II, and a significantly lower arterial pH. The respiratory rate decreased significantly within 1 h of starting NIV only in patients successfully treated with NIV. An APACHE II score of more than 17 (P = 0.022) and a respiratory rate of more than 25 breaths x min(-1) after 1 h of NIV (P = 0.024) were independent factors associated with the need for endotracheal intubation. Patients who avoided endotracheal intubation had a significantly lower ICU mortality rate and in-hospital mortality rate than patients who required endotracheal intubation. We determined an APACHE II score of more than 17 and a respiratory rate of more than 25 breaths x min(-1) after 1 h of NIV as factors predicting the need for endotracheal intubation in ALI patients treated with NIV.

The acute respiratory distress syndrome: Evolution of concepts and progress

The acute respiratory distress syndrome (ARDS) is a common and catastrophic form of acute respiratory failure, caused by a number of direct and indirect insults to the lung. Inflammatory pulmonary edema and alveolar collapse are central to ARDS. Numerous redundant mechanisms are involved which include oxidants neutrophils products and other inflammatory mediators. Surfactant is damaged or destroyed. Supportive treatment with low tidal volume ventilation and positive end expiratory pressure is the standard of care. No specific pharmacologic agent has been shown to alter the course of disease. Survivors may have varying degrees of pulmonary insufficiency, or may be normal. Most survivors have a good prognosis and quality of life.

The role of respiratory control disorders in SIDS

Although sudden death in infants resulting from cardiac arrhythmias are well documented these appear to account for no more than 5-10% of SIDS cases. Sudden respiratory failure currently is viewed as the most likely cause of death in the remainder. Accidental asphyxiation appears to have a causal role in less then 50% of deaths diagnosed as SIDS. The rest are most likely do to some form of acute respiratory failure. Although failure of autoresuscitation or failure to arouse from sleep likely contribute to the final sequence of events leading to at least some SIDS deaths, these cannot be regarded as causes of the primary respiratory failure initiating the fatal sequence. Past and current studies provide strong circumstantial evidence that obstructive sleep apnea and/or apnea of prematurity likely account for respiratory failure leading to SIDS in some or many deaths. In drawing conclusions it is well to recognize that mechanisms leading to death in SIDS are heterogeneous and therefore there is room for several plausible theories for respiratory or circulatory abnormalities contributing to SIDS.

Acute Applications of Noninvasive Positive Pressure Ventilation

Noninvasive positive-pressure ventilation (NPPV) has been used increasingly to treat acute respiratory failure (ARF). The best indications for its use are ARF in patients with COPD exacerbations, acute pulmonary edema, and immunocompromised states. For these indications, multiple controlled trials have demonstrated that therapy with NPPV avoids intubation and, in the case of COPD and immunocompromised patients, reduces mortality as well. NPPV is used to treat patients with numerous other forms of ARF, but the evidence is not as strong for its use in those cases, and patients must be selected carefully. The best candidates for NPPV are able to protect their airway, are cooperative, and are otherwise medically stable. Success is optimized when a skilled team applies a well-fitted, comfortable interface. Ventilator settings should be adjusted to reduce respiratory distress while avoiding excessive discomfort, patient-ventilator synchrony should be optimized, and adequate oxygenation should be assured. The appropriate application of NPPV in the acute care setting should lead to improved patient outcomes and more efficient resource utilization.

Epidemiology and outcome of acute respiratory failure in intensive care unit patients.

To summarize the prevalence of various forms of acute respiratory failure in acutely ill patients and review the major factors involved in the outcome of these patients. MEDLINE search for published studies reporting the prevalence or outcome for patients with acute respiratory failure and cited reference studies and abstracts from a recent international meeting in the intensive care medicine field. From the selected articles, information was obtained regarding the prevalence of acute respiratory failure, including acute respiratory distress syndrome and acute lung injury as defined by the North American-European Consensus Conference, the outcome, and the factors influencing mortality rates in this population of patients. The prevalence of acute respiratory failure varies according to the definition used and the population studied. Nonsurvivors of acute respiratory distress syndrome die predominantly of respiratory failure in <20% of cases. The relatively high mortality rates of acute lung injury/acute respiratory distress syndrome are primarily related to the underlying disease, the severity of the acute illness, and the degree of organ dysfunction.