The use of noninvasive positive pressure ventilation in the emergency department: results of a randomized clinical trial

Step-forward randomization in multicenter emergency treatment clinical trials

The authors present a new centralized randomization method for multicenter emergency treatment clinical trials. With this step-forward method, treatment randomization for the next subject is performed immediately after the enrollment of the current subject. This design ensures the readiness of the treatment assignment for each subject at the point of study enrollment, and it simultaneously provides effective control on treatment assignments balance and distributions of covariates. The authors also discuss procedures of the step-forward randomization method along with its implementation for two National Institute of Neurological Disorders and Stroke-funded multicenter acute stroke trials, one double-blinded and one open-labeled. Advantages and limitations are presented based on experience gained in these two trials.

Noninvasive Ventilation in Immunosuppressed Patients

In immunosuppressed patients (ISP) with acute respiratory failure (ARF), invasive mechanical ventilation (IMV) is associated with high mortality rate. Noninvasive ventilation (NIV) is a type of mechanical ventilation that does not require an artificial airway. It has seen increasing use in critically ill patients to avoid endotracheal intubation. Acute respiratory failure due to pulmonary infections is an important cause of illness in ISP and their treatment. Immunosuppressive treatments have showed an increase not only in the survival but also in the susceptibility to infection. Several authors have underlined the worst prognosis for neutropenic patients with ARF requiring endotracheal intubation and IMV. The NIV seems to be an interesting alternative in ISP because of the lower risk of complications; it prevents endotracheal intubation and its associated complications with survival benefits in this population.

Patient outcomes after noninvasive mechanical ventilation at a high dependency unit of an emergency department

OBJECTIVE

To describe the outcome of patients after noninvasive ventilation in a high dependency unit (HDU) of an emergency department (ED). Secondary aims were to define the role of intensive care consultation and to identify variables associated with mortality.

METHODS

Observational, prospective 6-month study.

RESULTS

Two hundred and nine cases were analysed. Thirty-four patients were initially rejected by the intensive care unit (ICU). Physicians in the ED did not request ICU consultation in the remaining 175 (83%) because of 'belief of improvable medical condition in the ED in patients without therapeutic limits' in 93 (group 1) and to 'preset therapeutic limits' or 'comfort measures only' in 82 (groups 2 and 3). Ten out of these 175 were subsequently admitted to the ICU. The global in-hospital mortality rate was 22% (3.3% in the high dependency unit), but only 10% in group 1. Place of referral for ventilation (P<0.001), absence of subsequent ventilation on the general ward (P<0.001), group of assignation (P=0.004), intensive care initial rejection (P=0.022), no previous home ventilation (P=0.028), older age (P=0.03) and longer duration on ventilation (P=0.047) were significantly associated with mortality. In the multivariate regression model, ventilating patients from general wards (odds ratio=7.1; 2.3-25, 95% confidence interval) and ventilation under preset limits (odds ratio=3.57; 1.42-8.98, 95% confidence interval) remained significantly associated with mortality.

CONCLUSION

Noninvasive ventilation is a relatively safe and effective treatment in the ED when performed in carefully controlled settings. ICU consultation may be securely deferred in this setting.

Use of noninvasive positive-pressure ventilation in the emergency department

To optimize the successful use of noninvasive positive-pressure ventilation (NPPV) in the emergency department (ED), clinicians must acquire the necessary knowledge, experience, and skill in its proper application. The purpose of this article is to provide a concise but thorough review of the current state of knowledge relating to the proper application of NPPV pertaining to its use in the ED.

A controlled trial of noninvasive ventilation for chronic obstructive pulmonary disease exacerbations

PURPOSE

This prospective, multicenter, double-blind, placebo-controlled study tested the hypothesis that noninvasive positive pressure ventilation reduces the need for endotracheal intubation in patients hospitalized in a pulmonary ward because of acute exacerbation of chronic obstructive pulmonary disease.

MATERIALS AND METHODS

Seventy-five consecutive patients with exacerbation (pH, 7.31 +/- 0.02; Pao(2), 45 +/- 9 mm Hg; Paco(2), 69 +/- 13 mm Hg) were randomly assigned to receive noninvasive ventilation or sham noninvasive ventilation during the first 3 days of hospitalization on top of standard medical treatment.

RESULTS

The need for intubation (according to predefined criteria) was lower in the noninvasive ventilation group (13.5% vs 34%, P < .01); in 31 patients with pH not exceeding 7.30, these percentages were 22% and 77%, respectively (P < .001). Arterial pH and Paco(2) improved in both groups, but changes were enhanced by noninvasive ventilation. Length of stay was lower in the noninvasive ventilation group (10 +/- 5 vs 12 +/- 6 days, P = .06). In-hospital mortality was similar in both groups.

CONCLUSIONS

These results demonstrate that noninvasive positive pressure ventilation, in a pulmonary ward, reduces the need for endotracheal intubation, particularly in the more severe patients, and leads to a faster recovery in patients with acute exacerbation of chronic obstructive pulmonary disease.

Defining, treating and preventing hospital acquired pneumonia: European perspective

INTRODUCTION

Many controversies still remain in the management of hospital acquired pneumonia (HAP), and ventilation-acquired pneumonia (VAP), Three European Societies, European Respiratory Society (ERS), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and European Society of Intensive Care Medicine (ESICM), were interested in producing a document on HAP and VAP with European perspective.

MATERIALS AND METHODS

The scientific committees from each Society designated one chairman; Antoni Torres (ERS), Harmut Lode (ESCMID) and Jean Carlet (ESICM). The chairmen of this Task Force suggested names from each Society to be a member of the panel. They also choose controversial topics on the field and others that were not covered by the last IDSA/ATS guidelines. Each topic was assigned to a pair of members to be reviewed and written. Finally, the panel defined 20 consensual points that were circulated several times among the members of the panel until total agreement was reached. A combination of evidences and clinical-based medicine was used to reach these consensus.

CONCLUSION

This manuscript reviews in depth several controversial or new topics in HAP and VAP. In addition 20 consensual points are presented. This manuscript may be useful for the development of future guidelines and to stimulate clinical research by lying out what is currently accepted and what is unknown or controversial.

Noninvasive mechanical ventilation in patients with chronic obstructive pulmonary disease and severe hypercapnic neurological deterioration in the emergency room

OBJECTIVES

The objective of this study was to assess the effectiveness of noninvasive motion ventilation (NIMV) in patients with chronic obstructive pulmonary disease (COPD), having infectious exacerbation and severe hypercapnic neurological dysfunction in the emergency room.

DESIGN

This is a prospective interventional study.

SETTING

The study setting was the emergency room at the Military Hospital in Guayaquil, Ecuador.

PATIENTS

A total of 24 patients were studied. Twelve patients had acute exacerbation of their chronic obstructive pulmonary disease: they presented at the emergency room with severe neurological dysfunction, with a Glasgow Coma Scale (GCS) score of less than 8 and a pH of less than 7.25. These patients were compared with 12 controls who were being treated with invasive mechanical ventilation (IMV), who were then matched according to their GCS scores, pH status, Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, and age.

INTERVENTIONS

We evaluated the effectiveness and safety of applying a ventilatory strategy based on a biphasic positive airway pressure protocol in the emergency room.

MEASUREMENTS AND RESULTS

The pH, PCO2, and GCS scores, measured during the first 3 h, were predictors of success for the application of NIMV treatment (P<0.05). Mortality was 33.3 and 16.7% for the IMV and the NIMV groups, respectively (P=0.01). Days of IMV were 5.60+/-1.2 versus 3.6+/-1.1 for NIMV (P=0.006). Days of hospitalization were 11.1+/-4.7 for the IMV group and 6.5+/-1.9 for the NIMV group (P=0.001). The cumulative survival rates at 6 months were 71.4 and 80% for the IMV and NIMV groups, respectively (P=0.80).

CONCLUSION

We consider that severe neurological dysfunction and pH of less than 7.25 do not constitute absolute contraindications to the use of NIMV. This kind of management can be implemented in the emergency room with favorable results.

Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary edema

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) has been widely used to alleviate signs and symptoms of respiratory distress due to cardiogenic pulmonary edema. NPPV prevents alveolar collapse and helps redistribute intra-alveolar fluid, improving pulmonary compliance and reducing the pressure of breathing.

OBJECTIVES

To determine the effectiveness and safety of NPPV in the treatment of adult patients with cardiogenic pulmonary edema.

SEARCH STRATEGY

We undertook a comprehensive search of the following databases in April 2005: CENTRAL, MEDLINE, EMBASE, CINAHL, DARE and LILACS. We also reviewed reference lists of included studies and contacted experts, equipment manufacturers, and the Cochrane Heart Group. We did not apply language restrictions.

SELECTION CRITERIA

We selected blinded or unblinded randomized or quasi-randomized clinical trials, reporting on adult patients with acute or acute-on-chronic cardiogenic pulmonary edema and where NPPV (continuous positive airway pressure (CPAP)) and/or bilevel NPPV plus standard medical care was compared with standard medical care alone.

DATA COLLECTION AND ANALYSIS

Two authors independently selected articles and abstracted data using a standardized data collection form. We evaluated study quality with emphasis on allocation concealment, adherence to the intention-to-treat principle and losses to follow-up.

MAIN RESULTS

We included 21 studies involving 1,071 participants. Compared to standard medical care, NPPV significantly reduced hospital mortality (RR 0.6, 95% CI 0.45 to 0.84) and endotracheal intubation (RR 0.53, 95% CI 0.34 to 0.83) with numbers needed to treat of 13 and 8, respectively. We found no difference in hospital length of stay with NPPV, however, intensive care unit stay was reduced by 1 day (WMD -1.07 days, 95% CI -1.60 to -0.53). Compared to standard medical care, we did not observe significant increases in the incidence of acute myocardial infarction with NPPV during (RR 1.24, 95% CI 0.79 to 1.95) or after (RR 0.82, 95% CI 0.09 to 7.54) its application.

AUTHORS' CONCLUSIONS

NPPV, especially CPAP, in addition to standard medical care is an effective and safe intervention for the treatment of adult patients with acute cardiogenic pulmonary edema.

Noninvasive positive pressure ventilation in acute respiratory failure due to COPD vs other causes: effectiveness and predictors of failure in a respiratory ICU in North India

OBJECTIVES

To determine the effectiveness of noninvasive positive pressure ventilation (NIPPV), and the factors predicting failure of NIPPV in acute respiratory failure (ARF) due to chronic obstructive pulmonary disease (COPD) versus other causes of ARF.

PATIENTS AND METHODS

This was a prospective observational study and all patients with ARF requiring NIPPV over a one-and-a-half year period were enrolled in the study. We recorded the etiology of ARF and prospectively collected the data for heart rate, respiratory rate, arterial blood gases (pH, partial pressure of oxygen in the arterial blood [PaO2], partial pressure of carbon dioxide in arterial blood [PaCO2]) at baseline, one and four hours. The patients were further classified into two groups based on the etiology of ARF as COPD-ARF and ARF due to other causes. The primary outcome was the need for endotracheal intubation during the intensive care unit (ICU) stay.

RESULTS

During the study period, 248 patients were admitted in the ICU and of these 63 (25.4%; 24, COPD-ARF, 39, ARF due to other causes; 40 male and 23 female patients; mean [standard deviation] age of 45.7 [16.6] years) patients were initiated on NIPPV. Patients with ARF secondary to COPD were older, had higher APACHE II scores, lower respiratory rates, lower pH and higher PaCO2 levels compared to other causes of ARF. After one hour there was a significant decrease in respiratory rate and heart rate and decline in PaCO2 levels with increase in pH and PaO2 levels in patients successfully managed with NIPPV. However, there was no difference in improvement of clinical and blood gas parameters between the two groups except the rate of decline of pH at one and four hours and PaCO2 at one hour which was significantly faster in the COPD group. NIPPV failures were significantly higher in ARF due to other causes (15/39) than in ARF-COPD (3/24) (p = 0.03). The mean ICU and hospital stay and the hospital mortality were similar in the two groups. In the multivariate logistic regression model (after adjusting for gender, APACHE II scores and improvement in respiratory rate, pH, PaO2 and PaCO2 at one hour) only the etiology of ARF, ie, ARF-COPD, was associated with a decreased risk of NIPPV failure (odds ratio 0.23; 95% confidence interval, 0.58-0.9).

CONCLUSIONS

NIPPV is more effective in preventing endotracheal intubation in ARF due to COPD than other causes, and the etiology of ARF is an important predictor of NIPPV failure.

Noninvasive ventilation in patients with chronic obstructive airway disease

Recent years have seen the emergence of noninvasive ventilation (NIV) as an important tool for management of patients with acute exacerbation of chronic obstructive pulmonary disease (COPD). Several well conducted studies in the recent years have established its role in the initial, as well as later management of these patients. However, some grey areas remain. Moreover, data is emerging on the role of long term nocturnal NIV use in patients with very severe stable COPD. This review summarizes the evidence supporting the use of NIV in various stages of COPD, discuss the merits as well as demerits of this novel ventilatory strategy and highlight the grey areas in the current body of knowledge.

Continuous positive airway pressure versus bilevel noninvasive ventilation in acute cardiogenic pulmonary edema: a randomized multicenter trial

STUDY OBJECTIVE

Patients with acute cardiogenic pulmonary edema may develop respiratory failure. Noninvasive respiratory support should be initiated rapidly to avoid tracheal intubation. The aim of this study is to compare the efficacy of continuous positive airway pressure (CPAP) delivered by the Boussignac CPAP device and bilevel positive airway pressure (bilevel PAP) in patients with acute respiratory failure caused by acute cardiogenic pulmonary edema.

METHODS

This prospective multicenter randomized study was conducted in 3 emergency departments. Patients were assigned to Boussignac CPAP through a facemask or to bilevel PAP, in addition to standard therapy. The main outcome was a combined criterion (tracheal intubation, death, or acute myocardial infarction). Complications, durations of ventilation, and hospitalization were also assessed.

RESULTS

After 1 hour of ventilation and at the end of the ventilation period, clinical parameters of respiratory distress and blood gas exchange significantly improved in each treatment arm. No significant differences were observed between the Boussignac CPAP and bilevel PAP arms for the combined criterion (5% versus 12%, respectively; odds ratio [OR] 0.4; 95% confidence interval [CI] 0.0 to 1.9) and also for severe complications (9% versus 6%; OR 1.5; 95% CI 0.3 to 9.9), duration of ventilation (median for both groups 2 hours; interquartile range [IQR] 1.2 to 3.0 hours), duration of hospitalization (CPAP 8.5 [IQR 6 to 14] days; bilevel PAP 10 [IQR 7 to 16] days), or intrahospital mortality (8% versus 14%; OR 1.8 [IQR 0.4 to 8.8]). Similar results were obtained among hypercapnic patients (PaCO2 >45 mm Hg). Whatever the ventilation support used, the combined criterion and severe complications were more frequently observed among hypercapnic patients.

CONCLUSION

Both Boussignac CPAP and bilevel PAP appeared effective in rapidly improving respiratory distress even in hypercapnic patients, but they were not different in terms of patient outcome.

Noninvasive Ventilation Using a Mouthpiece in Patients with Chronic Obstructive Pulmonary Disease and Acute Respiratory Failure

BACKGROUND

Noninvasive positive pressure ventilation (NPPV) delivered via a mouthpiece (mNPPV) has been successfully used in stable chronic restrictive respiratory insufficiency, but not in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory failure (ARF).

OBJECTIVES

The purpose of this matched case-control study was to compare the usefulness of mNPPV to noninvasive ventilation using a nasal or oronasal mask (nNPPV) or standard medical treatment (SMT) in COPD patients with ARF.

METHODS

Twenty-nine patients receiving mNPPV were matched with 29 patients receiving nNPPV and 29 patients receiving SMT regarding age, SAPSII, admission PaCO(2) and pH.

RESULTS

In the mNPPV group, admission PaCO(2) and pH were 78.6 +/- 12 mm Hg and 7.30 +/- 0.04, respectively. mNPPV and nNPPV avoided the need for endotracheal intubation in 27 and 25 patients, respectively (nonsignificant) whereas SMT resulted in a higher mechanical ventilation rate (13 patients). At the end of the treatment protocol, PaCO(2) was lower in the mNPPV group (62.2 +/- 9.6 mm Hg) than in the SMT group (72.4 +/- 20.4 mm Hg, p < 0.018) leading to a significantly higher pH. No significant differences were observed between the mNPPV and nNPPV groups.

CONCLUSIONS

In case of moderate respiratory acidosis, noninvasive ventilation using a mouthpiece significantly reduces the endotracheal intubation rate in comparison with SMT and therefore appears to be a second-line alternative to noninvasive ventilation delivered via a mask, especially when poorly tolerated.

Benefits and risks of success or failure of noninvasive ventilation

OBJECTIVE

Noninvasive ventilation (NIV) fails more frequently for de novo acute respiratory failure (de novo) than for cardiogenic pulmonary edema (CPE) or acute-on-chronic respiratory failure (AOC). The impact of NIV failure and success was compared between de novo and CPE or AOC after adjustment for disease severity.

SETTINGS

Patients requiring ventilatory support were enrolled in a prospective survey in 70 French ICUs. Of 1076 patients requiring ventilatory support, 524 were eligible, including 299 de novo (NIV use, 30%) and 225 CPE-AOC (NIV use, 55%).

DESIGN AND ANALYSIS

Independent risk factors associated with mortality and length of stay were identified by logistic regression analysis. The adjusted outcome of NIV success or failure was compared to that with endotracheal intubation without NIV.

RESULTS

NIV success was independently associated with survival in both de novo, adjusted OR 0.05 (95% CI 0.01-0.42), and CPE-AOC OR 0.03 (CI 0.01-0.24). NIV failure was associated with ICU mortality in the de novo group (OR 3.24, CI 1.61-6.53) but not in the CPE-AOC group. Nosocomial pneumonia was less common in patients successful with NIV. NIV failure was associated with a longer ICU stay in CPE-AOC only. The overall use of NIV was independently associated with a better outcome only in CPE-AOC patients (OR 0.33, CI 0.15-0.73).

CONCLUSION

The effect of NIV differs between de novo and CPE-AOC patients because NIV failure is associated with increased mortality for de novo patients. This finding should raise a note of caution when applying NIV in this indication.

Clinical practice and risk factors for immediate complications of endotracheal intubation in the intensive care unit: a prospective, multiple-center study

OBJECTIVES

To describe the current practice of physicians, to report complications associated with endotracheal intubation (ETI) performed in THE intensive care unit (ICU), and to isolate predictive factors of immediate life-threatening complications.

DESIGN

Multiple-center observational study.

SETTING

Seven intensive care units of two university hospitals.

PATIENTS

: We evaluated 253 occurrences of ETI in 220 patients.

INTERVENTIONS

From January 1 to June 30, 2003, data related to all ETI performed in ICU were collected. Information regarding patient descriptors, procedures, and immediate complications were analyzed.

MEASUREMENTS AND MAIN RESULTS

The main indications to intubate the trachea were acute respiratory failure, shock, and coma. Some 148 ETIs (59%) were performed by residents. At least one severe complication occurred in 71 ETIs (28%): severe hypoxemia (26%), hemodynamic collapse (25%), and cardiac arrest (2%). The other complications were difficult intubation (12%), cardiac arrhythmia (10%), esophageal intubation (5%), and aspiration (2%). Presence of acute respiratory failure and the presence of shock as an indication for ETI were identified as independent risk factors for occurrence of complications, and ETI performed by a junior physician supervised by a senior (i.e., two operators) was identified as a protective factor for the occurrence of complications.

CONCLUSIONS

ETI in ICU patients is associated with a high rate of immediate and severe life-threatening complications. Independent risk factors of complication occurrence were presence of acute respiratory failure and presence of shock as an indication for ETI. Further studies should aim to better define protocols for intubation in critically ill patients to make this procedure safer.

Non-invasive positive pressure ventilation in acute respiratory failure: providing competent care

Non-invasive positive pressure ventilation (NPPV) has been used as an alternative strategy to provide ventilatory support for patients with acute respiratory failure. Most studies demonstrate that the use of NPPV in acute respiratory failure results in a reduction in the need for endotracheal intubation and an overall survival advantage. However, current evidence, in the form of randomised controlled trials, suggests that these benefits may be restricted to patients suffering from acute exacerbation of chronic obstructive pulmonary disease (COPD). The clinical application of NPPV involves the development of competence in delivering the particular intervention. Clinical outcomes and thus valid comparisons with alternate methods of ventilatory support can only be made if attention is paid to the clinical indications for the application of NPPV and patient subgroups it is used to treat and the level of competence of care givers in its application and delivery. One essential element of competence is the establishment of an appropriate knowledge base and the development of clinical practice guidelines. This literature review identifies the current indications for NPPV and the relevant information for developing clinical practice guidelines for the management of this form of ventilatory support.

Noninvasive positive pressure ventilation: five years of experience in a pediatric intensive care unit

OBJECTIVES

To evaluate the feasibility and outcome of noninvasive positive pressure ventilation (NPPV) in daily clinical practice.

DESIGN

Observational retrospective cohort study.

SETTING

Pediatric intensive care unit in a university hospital.

PATIENTS

: Patients treated by NPPV, regardless of the indication, during five consecutive years (2000-2004).

MEASUREMENTS AND RESULTS

A total of 114 patients were included, and 83 of the 114 patients (77%) were successfully treated by NPPV without intubation (NPPV success group). The success rate of NPPV was significantly lower (22%) in the patients with acute respiratory distress syndrome (p < .05) than in the other patients. The Pediatric Risk of Mortality II (p = .003) and Pediatric Logistic Organ Dysfunction scores (p = .002) at admission were significantly higher in patients who were unsuccessfully treated with NPPV (NPPV failure group). Baseline values of Pco2, pulse oximetry, and respiratory rate did not differ between the two groups. A significant decrease in Pco2 and respiratory rate within the first 2 hrs of NPPV was observed in the NPPV success group. Multivariate analysis showed that a diagnosis of acute respiratory distress syndrome (odds ratio, 76.8; 95% confidence interval, 4.4-1342; p = .003) and a high Pediatric Logistic Organ Dysfunction score (odds ratio, 1.09; 95% confidence interval, 1.01-1.17; p = .01) were independent predictive factors for NPPV failure. A total of 11 patients (9.6%), all belonging to the NPPV failure group, died during the study.

CONCLUSIONS

This study demonstrates the feasibility and efficacy of NPPV in the daily practice of a pediatric intensive care unit. This ventilatory support could be proposed as a first-line treatment in children with acute respiratory distress, except in those with a diagnosis of acute respiratory distress syndrome.

Airway management and artificial ventilation in intensive care

PURPOSE OF REVIEW

This article defines the indication for airway-securing measures and describes the actual state of knowledge about the available techniques. Various modes of ventilation and their rationale are presented.

RECENT FINDINGS

New techniques in airway management and ventilation strategy are presented, explained and evaluated.

SUMMARY

Respiratory failure is a major confounding factor of morbidity and mortality in critical care patients and contributes considerably to prolonged intensive-care unit stay. When respiratory impairment is acute, rapid assessment of essential respiratory functions such as airway patency, gas exchange, and cough function have the highest priority in patients in life-threatening conditions. Securing the airway is a basic and vital procedure that has to be applied either in an elective or an emergency situation. Various levels of difficulty in laryngoscopy, intubation and maintaining oxygenation can occur and require standardized protocols, an adequate level of expertise and appropriate equipment. In intubated patients as well as in patients without secured airway, ventilatory assistance of various degrees and invasivities may be required. In this article all clinically applied forms of ventilation, their advantages and disadvantages as well as the relevant settings are extensively presented and discussed.

Should I wheel out the Heliox with non-invasive ventilation?

Heliox is a mixture of helium and oxygen; the most common combination in the UK is oxygen 21%, helium 79%. The substitution of helium for nitrogen produces a gas that is significantly less dense than air; this provides improved gas flow characteristics when turbulent flow might be encountered. Gas flow is said to be turbulent only in the larger airways and thus there is a logical use for heliox in upper airway obstruction.

Noninvasive Positive Pressure Ventilation in Patients with Respiratory Failure due to Severe Acute Pancreatitis

BACKGROUND

Patients with acute pancreatitis (AP) who require mechanical ventilation have high morbidity and mortality rates. Noninvasive positive pressure ventilation (NPPV) delivered through a mask has become increasingly popular for the treatment of acute respiratory failure (ARF) and may limit some mechanical ventilation complications.

OBJECTIVES

The purpose of this retrospective, observational study was to evaluate our clinical experience with the use of NPPV in AP patients with ARF.

METHODS

From 1997 to 2003, we documented clinical data, gas exchange and outcome of the 62 AP patients admitted to our intensive care unit. Patients who benefited from NPPV (success) were compared with those who failed (intubated).

RESULTS

Twenty-nine patients were intubated at admission and 5 did not develop ARF. Of the 28 patients treated with NPPV, 15 were not intubated (54%). Both groups had a similar PaO(2)/FiO(2) ratio (142 +/- 21 vs. 133 +/- 20; p = 0.127) and severity of illness (Ranson and Balthazar scores). Presence of atelectasis, bilateral alveolar infiltrates and abdominal distension were associated with failure of NPPV. Oxygenation improved and respiratory rate decreased significantly only in the success group. Additionally, the length of stay at the intensive care unit was significantly lower in the success group.

CONCLUSION

NPPV is feasible and safe to treat ARF in selected patients with AP who require ventilatory support.

Efficacy and safety of non-invasive ventilation in the treatment of acute cardiogenic pulmonary edema--a systematic review and meta-analysis

INTRODUCTION

Continuous positive airway pressure ventilation (CPAP) and non-invasive positive pressure ventilation (NPPV) are accepted treatments in acute cardiogenic pulmonary edema (ACPE). However, it remains unclear whether NPPV is better than CPAP in reducing the need for endotracheal intubation (NETI) rates, mortality and other adverse events. Our aim was to review the evidence about the efficacy and safety of these two methods in ACPE management.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials on the effect of CPAP and/or NIPV in the treatment of ACPE, considering the outcomes NETI, mortality and incidence of acute myocardial infarction (AMI). We searched six electronic databases up to May 2005 without language restrictions, reviewed references of relevant articles, hand searched conference proceedings and contacted experts.

RESULTS

Of 790 articles identified, 17 were included. In a pooled analysis, 10 studies of CPAP compared to standard medical therapy (SMT) showed a significant 22% absolute risk reduction (ARR) in NETI (95% confidence interval (CI), -34% to -10%) and 13% in mortality (95%CI, -22% to -5%). Six studies of NPPV compared to SMT showed an 18% ARR in NETI (95%CI, -32% to -4%) and 7% in mortality (95%CI, -14% to 0%). Seven studies of NPPV compared to CPAP showed a non-significant 3% ARR in NETI (95%CI, -4% to 9%) and 2% in mortality (95%CI, -6% to 10%). None of these methods increased AMI risk. In a subgroup analysis, NPPV did not lead to better outcomes than CPAP in studies including more hypercapnic patients.

CONCLUSION

Robust evidence now supports the use of CPAP and NPPV in ACPE. Both techniques decrease NETI and mortality compared to SMT and none shows increased AMI risk. CPAP should be considered a first line intervention as NPPV did not show a better efficacy, even in patients with more severe conditions, and CPAP is cheaper and easier to implement in clinical practice.

Noninvasive positive pressure ventilation in the intensive care unit: A concise review

OBJECTIVE

To critically assess available high-level clinical studies regarding use of noninvasive positive pressure ventilation in varied intensive care unit settings.

DATA SOURCE

Search of pertinent articles within Ovid MEDLINE from 1975 to 2005, CINAHL from 1982 to 2005, EMBASE from 1988 to 2005, and Web of Science from 1993 to 2005.

STUDY SELECTION

Randomized, controlled clinical trials and cohort studies and observational studies the authors consider important or novel.

DATA EXTRACTION/SYNTHESIS

Performed equally by both authors with the use of an Excel data spreadsheet.

CONCLUSION

There is abundant level I evidence supporting the use of noninvasive positive pressure ventilation in such critical care settings as acute hypercapnic respiratory failure, particularly related to chronic obstructive pulmonary disease, and acute cardiogenic pulmonary edema. We also report on other clinical scenarios in which the data may be somewhat less compelling, but evidence favors a noninvasive positive pressure ventilation trial. Some well designed studies suggest that noninvasive positive pressure ventilation is not an appropriate intervention for patients who have failed endotracheal extubation.

Outcomes of Patients With Acute Respiratory Failure After Abdominal Surgery Treated With Noninvasive Positive Pressure Ventilation

OBJECTIVES

Little is known about the physiologic and clinical effects of noninvasive positive pressure ventilation (NPPV) in patients who have acute respiratory failure (ARF) after abdominal surgery. We evaluated our clinical experience with the use of NPPV in the treatment of ARF after abdominal surgery.

METHODS

We prospectively evaluated NPPV use during a 2-year period in a medical-surgical ICU of a university hospital. We documented demographic and diagnostic data, gas exchange, and clinical outcomes. We compared patients who were not intubated to those who were intubated after a trial of NPPV.

RESULTS

Of 72 patients with ARF after abdominal surgery who were treated with NPPV, 48 patients avoided intubation (67%). Patients in the intubated and nonintubated groups had similar demographic characteristics, and similar American Society of Anesthesiologists physical status and simplified acute physiology score II scores at admission. The intubated group had a significantly lower Pa(O2)/fraction of inspired oxygen (Fi(O2)) ratio (123 +/- 62 mm Hg vs 194 +/- 76 mm Hg, p < 0.01) and more extended bilateral alveolar infiltrates (67% vs 31%, p < 0.01) than the non-intubated group. Within the first NPPV observation period, the Pa(O2)/Fi(O2) increased (+ 36 +/- 29% [+/- SD], p = 0.04) and the respiratory rate decreased (28.2 +/- 3.4 breaths/min vs 23.1 +/- 3.8 breaths/min, p < 0.01) significantly only in the non-intubated group. The non-intubated group had significantly lower length of ICU stay (17.3 +/- 10.9 days vs 34.1 +/- 28.5 days, p < 0.01) and mortality rate (6% vs 29%, p < 0.01).

CONCLUSION

NPPV may be an alternative to conventional ventilation in selected patients with ARF after abdominal surgery who require ventilatory support.

Early and late failure of noninvasive ventilation in chronic obstructive pulmonary disease with acute exacerbation

BACKGROUND

Despite recent encouraging results, the use of noninvasive ventilation (NIV) in the management of acute exacerbations in chronic obstructive pulmonary disease (COPD), complicated by acute respiratory failure (ARF), is not always successful. Failure of NIV may require an immediate intubation after a few hours (usually 1-3) of ventilation ('early failure') or may result in clinical deterioration (one or more days later) after an initial improvement of blood gas tension and general conditions ('late failure').

MATERIALS AND METHODS

We enrolled 122 patients affected by COPD complicated by ARF, and treated with NIV. The schedule of NIV provided sessions of 2-6 h twice daily.

RESULTS

Ninety-nine (81%) patients showed a progressive improvement of the clinical parameters and were discharged. Among the remaining 23 patients, 13 had an early failure and 10 had a late failure. In the 'success' group and 'late failure' groups we found after an increase of pH 2 h of NIV (from 7.31 +/- 0.05 to 7.38 +/- 0.04 P < 0.001 and from 7.29 +/- 0.03 to 7.36 +/- 0.02 P < 0.001, respectively) and a decrease of PaCO2 (from 80.93 +/- 9.79 to 66.48 +/- 5.95 P < 0.001 and from 85.96 +/- 10.77 to 76.41 +/- 11.02 P < 0.001, respectively). After 2 h of NIV in the 'late failure' group there were no significant changes in terms of pH (from 7.20 +/- 0.10 to 7.28 +/- 0.06) nor PaCO2 (from 92.86 +/- 35.49 to 93.68 +/- 23.68). The 'early failure' group had different characteristics and, owing to more severe conditions, the value of pH, of Glasgow Coma Score, and Apache II Score were the best predictors of the failure; while, among the complications on admission, metabolic alterations were the only independently significant predictor.

CONCLUSIONS

Our study confirms that NIV may be useful to avoid intubation in approximately 80% of patients with COPD complicated by moderate-severe hypercapnic respiratory failure.

Randomised controlled comparison of continuous positive airways pressure, bilevel non-invasive ventilation, and standard treatment in emergency department patients with acute cardiogenic pulmonary oedema

BACKGROUND

Continuous positive airways pressure (CPAP) and bilevel non-invasive ventilation may have beneficial effects in the treatment of patients with acute cardiogenic pulmonary oedema. The efficacy of both treatments was assessed in the UK emergency department setting, in a randomised comparison with standard oxygen therapy.

METHODS

Sixty patients presenting with acidotic (pH<7.35) acute, cardiogenic pulmonary oedema, were randomly assigned conventional oxygen therapy, CPAP (10 cm H(2)O), or bilevel ventilation (IPAP 15 cm H(2)O, EPAP 5 cm H(2)O) provided by a standard ventilator through a face mask. The main end points were treatment success at two hours and in-hospital mortality. Analyses were by intention to treat.

RESULTS

Treatment success (defined as all of respiratory rate<23 bpm, oxygen saturation of>90%, and arterial blood pH>7.35 (that is, reversal of acidosis), at the end of the two hour study period) occurred in three (15%) patients in the control group, seven (35%) in the CPAP group, and nine (45%) in the bilevel group (p = 0.116). Fourteen (70%) of the control group patients survived to hospital discharge, compared with 20 (100%) in the CPAP group and 15 (75%) in the bilevel group (p = 0.029; Fisher's test).

CONCLUSIONS

In this study, patients presenting with acute cardiogenic pulmonary oedema and acidosis, were more likely to survive to hospital discharge if treated with CPAP, rather than with bilevel ventilation or with conventional oxygen therapy. There was no relation between in hospital survival and early physiological changes. Survival rates were similar to other studies despite a low rate of endotracheal intubation.

Factores de predicción del éxito de la ventilación no invasiva en el tratamiento del edema agudo de pulmón cardiogénico

BACKGROUND AND OBJECTIVE

Recent studies support the use of non invasive ventilation (NIV) in patients with acute cardiogenic pulmonary edema (ACPE). We aimed to evaluate the factors related to the success of the technique in patients admitted to an intensive care unit (ICU) with ACPE.

PATIENTS AND METHOD

An observational prospective study was performed in ICU.199 consecutive patients were enrolled with ACPE at admission who received treatment with NIV and standardized pharmacological treatment. The success of the NIV was achieved when endotracheal intubation was avoided and patients were alive without dyspnea within and 24 hours after discharge from the ICU. Clinical, physiological and gasometric parameters were analyzed at admission and one hour after starting NIV.

RESULTS

Patient's age was 74 years. 43% were male. The SAPS II was 45. 74.4% of the patients were successfully treated with NIV. 12.6% required endotracheal intubation. In a multivariate analysis, the success of the technique (values expressed as odds ratio [95% confidence interval]) was related to: SAPS II (0.95 [0.91-0.99]); the place of admission (6.78 [1.85-24.79]); value of PCO2 at admission (1.05 [1.01-1.09]); PO2/FiO2 index (1.03 [1.01-1.06]) and respiratory frequency (0.91 [0.84-0.99]) within the first hour; SOFA (acute failure organics score) (0.62 [0.49-0.78]); concomittant acute myocardial infarction (AMI) (0.05 [0.01-0.22]) and number of complications (0.17 [0.47-0.65]). The hospital mortality rate was 32.7%. The non intubation order (0.12 [0.04-0.32]) and the success of the technique (100.03 [28.71-348.47]) were related to the hospital mortality.

CONCLUSIONS

The success of NIV in the treatment of ACPE is related to a lower SAPS II, admission at the emergency department, elevated PCO2 at admission, improvement of the PO2/FiO2 index and the respiratory rate within the first hour. The non intubation order and the success of the technique were related to the hospital mortality.

Non-invasive ventilation in acute respiratory failure: a randomised comparison of continuous positive airway pressure and bi-level positive airway pressure

OBJECTIVES

To determine whether there is a difference in required duration of non-invasive ventilation between continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP) in the treatment of a heterogeneous group of emergency department (ED) patients suffering acute respiratory failure and the subgroup of patients with acute pulmonary oedema (APO). Secondary objectives were to compare complications, failure rate, disposition, length of stay parameters, and mortality between the treatments.

METHODS

This prospective randomised trial was conducted in the emergency departments of three Australian teaching hospitals. Patients in acute respiratory failure were randomly assigned to receive CPAP or BiPAP in addition to standard therapy. Duration of non-invasive ventilation, complications, failure rate, disposition, length of stay (hospital and ICU), and mortality were measured.

RESULTS

101 patients were enrolled in the study (CPAP 51, BiPAP 50). The median duration of non-invasive ventilation with CPAP was 123 minutes (range 10-338) and 132 minutes (range 20-550) for BiPAP (p = 0.206, Mann-Whitney). For the subgroup suffering APO, 36 were randomised to CPAP and 35 to BiPAP. For this group the median duration of non-invasive ventilation for CPAP was 123 minutes (range 35-338) and 133 minutes (range 30-550) for BiPAP (p = 0.320, Mann-Whitney).

CONCLUSIONS

These results suggest that there is no significant difference in the duration of non-invasive ventilation treatment between CPAP and BiPAP when used for the treatment of acute respiratory failure in the ED. There was also no significant difference between the groups in secondary end points.

The use of noninvasive ventilation in acute respiratory failure at a tertiary care center

OBJECTIVE

Financial constraints and bed limitations frequently prevent admission of ill patients to a critical care setting. We surveyed the use of treatment with noninvasive ventilation (NIV) in clinical practice by physicians in a tertiary care, university-based teaching hospital and compared our findings with published recommendations for the use of NIV.

METHODS

Data were collected prospectively on all patients with acute respiratory failure (ARF) for whom NIV was ordered over a 5-month period. The respiratory therapy department was responsible for administering NIV on written order by a physician. The respiratory therapist completed a survey form with patient tracking data for each initiation of NIV. The investigators then surveyed the clinical chart for clinical data.

RESULTS

NIV was utilized for the treatment of ARF on 75 occasions during the 5-month period. Fourteen patients (18%) received NIV for a COPD exacerbation, and 61 patients (82%) received it for respiratory failure of other etiologies. NIV was initiated in the emergency department in 32% of patients, in a critical care setting in 27% of patients, in a ward observation unit in 23% of patients, and on a general medical or surgical ward in 18% of patients. Arterial blood gases (ABGs) were measured on 68 occasions prior to the initiation of NIV, and 51 patients had an ABG measurement within the first 6 h of treatment. The mean pH at baseline was 7.29, and 33% of patients had a baseline pH of < 7.25. Seven patients required endotracheal intubation (ETI) [13%], and there were 18 deaths (24%) with patients having do-not-resuscitate orders, accounting for 12 deaths.

CONCLUSION

NIV is commonly used outside of a critical care setting. Our outcomes of ETI and death were similar to those cited in the literature despite less aggressive monitoring of these patients.

Mechanical Ventilation

Mechanical ventilation is the second most frequently performed therapeutic intervention after treatment for cardiac arrhythmias in intensive care units today. Countless lives have been saved with its use despite being associated with a greater than 30% in-hospital mortality rate. As life expectancies increase and people with chronic illnesses survive longer, artificial support with mechanical ventilation is also expected to rise. In one survey, over half of senior internal medicine residents reported their training on mechanical ventilation as inadequate, whereas the majority of critical care nurses reported having received no formal education on its use. Technological advances resulting in the availability of sleeker ventilators with graphic waveform displays and new modes of ventilation have challenged the bedside clinicians to incorporate this new data along with evidenced-based research into their daily practice. A review of current thoughts on mechanical ventilation and weaning is presented.

Noninvasive vs invasive ventilation in COPD patients with severe acute respiratory failure deemed to require ventilatory assistance

OBJECTIVE

To determine whether non-invasive ventilation (NIV) may be an effective and safe alternative to invasive mechanical ventilation in chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF) meeting criteria for mechanical ventilation.

DESIGN AND SETTING

Matched case-control study conducted in ICU.

PATIENTS AND INTERVENTION

NIV was prospectively applied to 64 COPD patients with advanced ARF. Their outcomes were compared with those of a control group of 64 COPD patients matched on age, FEV(1), Simplified Acute Physiology Score II, and pH at ICU admission, previously treated in the same ICU with conventional invasive mechanical ventilation.

METHODS AND RESULTS

NIV failed in 40 patients who required intubation. Mortality rate, duration of mechanical ventilation, and lengths of ICU and post-ICU stay were not different between the two groups. The NIV group had fewer complications ( P = 0.01) and showed a trend toward a lower proportion of patients remaining on mechanical ventilation after 30 days ( P = 0.056). Compared to the control group, the outcomes of the patients who failed NIV were no different. Compared to the patients who received intubation, those who succeeded NIV had reduced mortality rate and lengths of ICU and post-ICU stay.

CONCLUSIONS

In COPD patients with advanced hypercapnic acute respiratory failure, NIV had a high rate of failure, but, nevertheless, provided some advantages, compared to conventional invasive ventilation. Subgroup analysis suggested that the delay in intubation was not deleterious in the patients who failed NIV, whereas a better outcome was confirmed for the patients who avoided intubation.

BiPAP ventilation as assistance for patients presenting with respiratory distress in the department of emergency medicine

BACKGROUND

Noninvasive ventilatory support (NIVS) is intended to provide ventilatory assistance for a wide range of respiratory disturbances. The use of NIVS for treatment of respiratory distress may be applicable in the emergency department (ED). It may prevent endotracheal intubation and, likewise, may favorably influence the course of the patient's hospitalization, depending on the primary disease or ventilatory disturbance.

OBJECTIVE

To evaluate the efficacy of bilevel positive airway pressure (BiPAP) ventilation in patients with acute respiratory distress presenting in the ED.

METHODS

A prospective, uncontrolled, nonrandomized, nonblind study enrolled 30 patients. They were cooperative and hemodynamically stable, aged over 18 years, and presented with acute respiratory distress as defined by predetermined criteria. They were connected to a BiPAP machine through a face mask, using an initial pressure of 8/3 cm H(2)O, which was gradually raised to 12/7 cm H(2)O inspiratory positive airway pressure/expiratory positive airway pressure. Standard drugs, inhalation and oxygen therapies were administered as needed. The BiPAP was disconnected either upon relief of respiratory distress or on deterioration of the patient's condition.

RESULTS

Of the 30 patients in the study, 19 had cardiogenic pulmonary edema, four had acute asthma, three had exacerbation of COPD, three had pneumonia and one had malignant pleural effusion. BiPAP was instituted subsequent to failure of standard therapies. Twenty-six patients were classified as responders to the BiPAP ventilation and four as nonresponders (three patients were intubated after 1 hour and one patient 24 hours, post BiPAP). The total length of stay (LOS) in the ED was 3-5 hours and the mean LOS in hospital was 4.1 +/- 1.5 days, versus 6.5 +/- 1.2 days in LOS reports of similar patients in the same hospital during 1999, who did not undergo BiPAP ventilation. No other complications were observed.

CONCLUSIONS

We found BiPAP ventilation simple, safe, effective and well tolerated by patients in respiratory distress. The rate of endotracheal intubation after successful BiPAP ventilation was low. In carefully selected patients with respiratory distress, BiPAP ventilation may successfully replace endotracheal intubation.

Review Articles: Nondialytic Management of Hyperkalemia and Pulmonary Edema Among End-Stage Renal Disease Patients: An Evaluation of the Evidence

Congestive heart failure (CHF) and hyperkalemia are the two leading reasons for emergency dialysis among individuals with end-stage renal disease (ESRD). While hemodialysis provides definitive treatment of both hyperkalemia and volume overload among ESRD patients, for those who present outside of "regular dialysis hours," institution of dialysis may be delayed. Nondialytic management can be instituted immediately and should be the initial therapy in the management of hyperkalemia and CHF in these individuals. Current available evidence does not allow conclusions as to whether treatment with nondialytic strategies alone results in different outcomes than nondialytic strategies coupled with emergent hemodialysis. Therefore, whether or not nondialytic management alone is appropriate remains a matter of individual judgment that should be decided on a case-by-case basis.

Non-invasive ventilation for acute respiratory disease

Non-invasive ventilation (NIV) has been shown to be effective in acute respiratory failure of various aetiologies in different health care systems and ward settings. It should be seen as complementary to invasive ventilation and primarily a means of preventing some patients from deteriorating to the point at which intubation is needed. Generally it is best initiated early before assisted ventilation is mandatory, although it has been shown to be effective even in very sick patients. Important benefits include the avoidance of endotracheal-tube-associated infections, which carry an important morbidity and mortality, and a reduction in health care costs. The most important ingredient for an acute NIV service is a well-trained enthusiastic ward team.

Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) is being used increasingly in the management of patients admitted to hospital with acute respiratory failure secondary to an exacerbation of chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine the efficacy of NPPV in the management of patients with respiratory failure due to an acute exacerbation of COPD.

SEARCH STRATEGY

An initial search was performed using the Cochrane Airways Group trials register and other relevant electronic databases. An updated search was conducted in September 2003 and another in April 2004.

SELECTION CRITERIA

Randomised controlled trials comparing NPPV plus usual medical care (UMC) versus UMC alone were selected. Trials needed to recruit adult patients admitted to hospital with respiratory failure due to an exacerbation of COPD and with PaCO2 > 6 kPa (45 mmHg).

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected articles for inclusion, evaluated methodological quality of the studies and abstracted the data.

MAIN RESULTS

Fourteen studies were included in the review. NPPV resulted in decreased mortality (Relative Risk 0.52; 95%CI 0.35 to 0.76), decreased need for intubation (RR 0.41; 95%CI 0.33 to 0.53), reduction in treatment failure (RR 0.48; 95%CI 0.37 to 0.63), rapid improvement within the first hour in pH (Weight Mean Difference 0.03; 95%CI 0.02 to 0.04), PaCO2 (WMD -0.40 kPa; 95%CI -0.78 to -0.03) and respiratory rate (WMD -3.08 bpm; 95%CI -4.26 to -1.89). In addition, complications associated with treatment (RR 0.38; 95%CI 0.24 to 0.60) and length of hospital stay (WMD -3.24 days; 95%CI -4.42 to -2.06) was also reduced in the NPPV group.

REVIEWERS' CONCLUSIONS

Data from good quality randomised controlled trials show benefit of NPPV as first line intervention as an adjunct therapy to usual medical care in all suitable patients for the management of respiratory failure secondary to an acute exacerbation of COPD. NPPV should be considered early in the course of respiratory failure and before severe acidosis ensues, as a means of reducing the likelihood of endotracheal intubation, treatment failure and mortality.

Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) is being used increasingly in the management of patients admitted to hospital with acute respiratory failure secondary to an exacerbation of chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine the efficacy of NPPV in the management of patients with respiratory failure due to an acute exacerbation of COPD.

SEARCH STRATEGY

An initial search was performed using the Cochrane Airways Group trials register and other relevant electronic databases. An updated search was conducted in September 2003.

SELECTION CRITERIA

Randomised controlled trials comparing NPPV plus usual medical care (UMC) versus UMC alone were selected. Trials needed to recruit adult patients admitted to hospital with respiratory failure due to an exacerbation of COPD and with PaCO(2) > 6 kPa (45 mmHg).

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected articles for inclusion, evaluated methodological quality of the studies and abstracted the data.

MAIN RESULTS

Fourteen studies were included in the review. NPPV resulted in decreased mortality (Relative Risk 0.52; 95%CI 0.35, 0.76), decreased need for intubation (RR 0.41; 95%CI 0.33, 0.53), reduction in treatment failure (RR 0.48; 95%CI 0.37, 0.63), rapid improvement within the first hour in pH (Weight Mean Difference 0.03; 95%CI 0.02, 0.04), PaCO(2) (WMD -0.40 kPa; 95%CI -0.78, -0.03) and respiratory rate (WMD -3.08 bpm; 95%CI -4.26, -1.89). In addition, complications associated with treatment (RR 0.38; 95%CI 0.24, 0.60) and length of hospital stay (WMD -3.24 days; 95%CI -4.42, -2.06) was also reduced in the NPPV group.

REVIEWER'S CONCLUSIONS

Data from good quality randomised controlled trials show benefit of NPPV as first line intervention as an adjunct therapy to usual medical care in all suitable patients for the management of respiratory failure secondary to an acute exacerbation of COPD. NPPV should be considered early in the course of respiratory failure and before severe acidosis ensues, as a means of reducing the likelihood of endotracheal intubation, treatment failure and mortality.

Community-acquired pneumonia in the elderly

CAP is traditionally considered a medical disease, and is managed with intravenous fluids and antibiotics on medical floors. Recent cost-containment efforts have shifted the provision of care to the outpatient settings, and only those with most severe disease and multiple comorbid illnesses are admitted to hospitals. Therefore, the proportion of hospitalized patients with severe CAP that need intensive care and life support is increasing. Furthermore, the incidence of severe CAP is also rising due to disproportionate growth of the elderly population that is most vulnerable to this deadly disease. Many of these elderly patients have advanced underlying diseases, and CAP might often be a terminal event superimposed on an underlying chronic debilitating illness. As ICU physicians, we need to be familiar with this disease, its complications, and its prognosis to provide intensive care in a timely and rational fashion in some patients, and refrain from life support in others. Just as prior efforts have sought to improve and standardize criteria for hospital admission, future efforts should aim to improve and standardize decisions regarding intensive care and life support in these very sick elderly patients. Future efforts in the management of CAP need to consider the postdischarge period where most deaths occur. Prevention is an important issue especially for those at high risk for CAP.

'Boussignac' continuous positive airway pressure system: practical use in a prehospital medical care unit

Continuous positive airway pressure in acute cardiogenic pulmonary edema is rarely used by prehospital emergency care units, because of the particular technical drawbacks of existing equipment. The aim of this one year prospective descriptive open study without a control group was to assess the technical feasibility of using the Boussignac continuous positive airway pressure system (Vygon) in a prehospital medical care service. Statistical comparisons were performed using Student's t-test or a Wilcoxon T-test. There were 57 decisions to use continuous positive airway pressure. Seven records were excluded. Four patients were intubated on the scene and six within one hour after hospital admission. The respiratory rate and transcutaneous oxygen saturation improved significantly for all of the other patients (Student's t-test P < 0.001). The Boussignac continuous positive airway pressure system has many advantages, including flexibility and pressure monitoring, lower oxygen consumption, and ease of use. These should allow this technique to be used more widely by prehospital teams.

Non-invasive ventilation delivered by conventional interfaces and helmet in the emergency department

Non-invasive positive pressure ventilation is increasingly used as a first-line treatment for respiratory failure. Non-invasive positive pressure ventilation can reduce the complications of endotracheal intubation such as barotrauma, nosocomial infections and the need for sedation. Non-invasive positive pressure ventilation has been shown to reduce the rate of endotracheal intubation in acute cardiogenic pulmonary oedema (27%), in chronic obstructive pulmonary disease (21%), and in acute respiratory failure (17%). Non-invasive positive pressure ventilation can be successfully delivered in the emergency department or in the general ward. However, the criteria for interrupting non-invasive positive pressure ventilation must be stricter (i.e. failure to improve gas exchange within 30 min) than in the general ward. One of the main reasons for the failure of non-invasive positive pressure ventilation lies in the technical problems caused by the face mask. We recently developed a new interface, the 'helmet', to deliver non-invasive positive pressure ventilation. When using the helmet instead of a face mask an increase of 10 cm H(2)O of pressure support and a fast pressurization rate are recommended. In a lung model and in healthy individuals the helmet reduced inspiratory effort. In hypoxemic patients the helmet reduced the intubation rate and the incidence of face mask-related complications. We believe that the helmet can extend the application of non-invasive positive pressure ventilation in different categories of patients with respiratory failure.