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In clinical practice, acidotic patients with acute cardiogenic pulmonary edema (ACPE) are commonly considered more severe in comparison with nonacidotic patients, and data on the outcome of these patients treated with noninvasive pressure support ventilation (NIV) are lacking.The present investigation was aimed at assessing whether acidosis on admission (pH < 7.35) was associated with adverse outcome in 65 consecutive patients with ACPE treated with NIV and admitted to our Intensive Cardiac Care Unit (ICCU).In our population, 28 patients were acidotic (28 of 65, 43.1%), whereas 41 patients were not (37 of 65, 56.9%). According to the Repeated Measures General Linear Model, pCO2 values significantly changed throughout the 2-h NIV treatment (P = 0.019) in both groups (P = 0001). In acidotic patients, pCO2 significantly decreased (51.9 ± 15.3 → 47.0 ± 12.8 → 44.8 ± 12.7), whereas they increased in the nonacidotic subgroup (36.8 ± 6.5 → 36.9 ± 7.2 → 37.6 ± 6.4). No difference was observed in intubation rate between acidotic (eight patients, 28.6%) and nonacidotic patients (12 patients, 32.4%) (P = 0.738). In-ICCU mortality rate did not differ between (13 patients, 35.1%) and nonacidotic patients (nine patients, 32.1%) (P = 0.801).Our data strongly suggest that in patients with severe ACPE treated with NIV, the presence of acidosis is not associated with adverse outcomes (early mortality and intubation rates) in these patients.

A 32-year-old woman (148 cm, 59 kg, gravida 2, para 2) with quadruplet pregnancy was admitted to our hospital for the threatened preterm labor at 23 weeks and 2 days of gestation. She was treated with ritodrine, magnesium sulfate and nifedipine to maintain tocolysis. Betamethasone was administered to accelerate fetal lung maturity. After ritodrine dose was increased at 23 weeks and 5 days of gestation, she developed dyspnea with desaturation. Acute pulmonary edema was revealed on chest X-ray. The decision was made to proceed with emergency cesarean delivery. On arrival at the operating room, the blood pressure was 123/53 mmHg, heart rate 111 beats x min(-1), and oxygen saturation (SpO2) 84% with supplemental oxygen 15 l x min(-1) via a reserved face mask. Noninvasive positive pressure ventilation (NPPV) was initiated with S/T mode (FIO2 1.0, inspiratory positive airway pressure 10 cmH2O, expiratory positive airway pressure 6 cmH2O). The dyspnea was improved with her SpO2 100%. Spinal anesthesia was performed at L 34 using 2.5 ml of 0.5% bupivacaine and 100 microg morphine. Throughout the operation (operation time 44 minutes), she did not develop dyspnea under NPPV. NPPV was discontinued after the operation. Her SpO2 declined, and pulmonary edema on chest X-ray was exacerbated. She was transferred to the intensive care unit and NPPV was continued for 22 hours after the operation. She was discharged from the intensive care unit on the next day and was discharged from the hospital on the 6th postoperative day.

Background: There have been no reports on the efficacy of noninvasive positive pressure ventilation (NPPV) in elderly patients., Objectives: The purpose of this study was to clarify the efficacy and identify the predictors of a successful outcome of NPPV in patients over the age of 75 years with acute hypercapnic respiratory failure (AHRF)., Methods: We retrospectively evaluated the data of 42 patients (21 men) with AHRF who were treated at our unit. The patients were divided into survivor and nonsurvivor groups, and the clinical parameters measured prior to the initiation of NPPV were compared between the 2 groups., Results: The mean age of the patients was 83.0 ± 6.3 years. The etiology of the respiratory failure was acute exacerbation of chronic obstructive pulmonary disease in 19 patients, acute cardiogenic pulmonary edema in 18 patients, idiopathic pulmonary fibrosis in 3 patients, sequelae of tuberculosis in 1 patient, and asthma in 1 patient. Of the 42 patients, 33 (78.6%) survived. All patients with a Glasgow Coma Scale (GCS) score ≥9 and/or an APACHE II score <29 survived after the initiation of NPPV., Conclusion: An APACHE II score <29 and a GCS score ≥9 were predictors of a successful outcome of NPPV in elderly people., (Copyright © 2011 S. Karger AG, Basel.)

Noninvasive ventilation (NIV) has become an integral part of critical care management. Despite > 2 decades of experience, it is relatively underused, with general utilization reported as a little over 10% in a recent international survey. Lack of training, knowledge, equipment, and experience with NIV may account for its slow adoption. Patient selection, staff training and experience, and prompt recognition of ineffective NIV are important components to successful application of NIV. Noninvasive ventilation does have a learning curve that may be steep for some institutions but must be mastered if the procedure is to become a successful institutional component of care. Patients with acute respiratory failure due to chronic obstructive pulmonary disease or congestive heart failure are ideal candidates for NIV, and optimal efficacy in associated conditions is often linked to these 2 conditions. Technical issues and written guidelines are addressed, including details of an adequate trial of therapy as well as criteria for intubation. Attention to these elements should increase the success rate of NIV, which in turn should increase its general use.

Non-invasive mechanical ventilation has been increasingly used to avoid or serve as an alternative to intubation. Compared with medical therapy, and in some instances with invasive mechanical ventilation, it improves survival and reduces complications in selected patients with acute respiratory failure. The main indications are exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, pulmonary infiltrates in immunocompromised patients, and weaning of previously intubated stable patients with chronic obstructive pulmonary disease. Furthermore, this technique can be used in postoperative patients or those with neurological diseases, to palliate symptoms in terminally ill patients, or to help with bronchoscopy; however further studies are needed in these situations before it can be regarded as first-line treatment. Non-invasive ventilation implemented as an alternative to intubation should be provided in an intensive care or high-dependency unit. When used to prevent intubation in otherwise stable patients it can be safely administered in an adequately staffed and monitored ward.

The use of non invasive ventilation (NIV) in the emergency setting to treat acute respiratory failure (ARF) has received much attention. To date, large studies support the early administration of continuous positive airway pressure (CPAP) in patients with cardiogenic acute pulmonary edema; and 2) non-invasive positive pressure ventilation (NPPV) for exacerbations of chronic obstructive pulmonary disease (COPD). NIV could also be useful in other types of ARF, but its success rate is dependent on the cause of ARF and patient's characteristics. Use of NIV in the emergency setting should take into account validated indications and local expertise of the nursing staff to minimize the risk of complications.

Objective: Noninvasive pressure support ventilation (NIPSV) delivered by face mask has proved an effective treatment for patients with acute pulmonary edema. However, an increase in acute myocardial infarction rate has been reported with this ventilation modality. We investigated whether the use of NIPSV increases the incidence of acute myocardial infarction compared with continuous positive airway pressure (CPAP) in patients with acute pulmonary edema., Design: Randomized, prospective, controlled study., Setting: Emergency Department, Niguarda Hospital of Milano (Italy)., Patients: Forty-six patients affected by acute pulmonary edema., Interventions: The patients received either NIPSV (24 patients) or CPAP (22 patients) through a face mask., Measurements and Main Results: Cardiac enzymes (myoglobin, creatine kinase isoenzyme MB, and troponin I) were determined and electrocardiographic and physiologic measurements made over the subsequent 36 hrs. No significant differences were observed in the incidence of acute myocardial infarction in the CPAP group (13.6%) compared with the NIPSV group (8.3%). Both modalities of noninvasive ventilation improved ventilation and vital signs in patients with acute pulmonary edema. Two patients of the NIPSV group (8.3%) and one of the CPAP group (4.5%) required endotracheal intubation because vital signs and arterial blood gases worsened 1 hr after the start of noninvasive ventilation. No significant differences were found in in-hospital mortality rate., Conclusions: NIPSV proved to be equally effective in improving vital signs and ventilation without increasing acute myocardial infarction rate in patients with nonischemic acute pulmonary edema in comparison to CPAP alone. However, because the study lacked statistical power and excluded patients with acute coronary syndromes, caution is still advised when applying NIPSV to the latter subgroup of patients.

Objectives: To assess efficacy and tolerability of a newly developed helmet for the delivery of non-invasive ventilation in patients with acute respiratory failure., Patients and Methods: Ten consecutive immunocompromised patients with acute respiratory failure admitted to our intensive care unit were included in the study. The patients were equipped with the helmet and non-invasive ventilation (NIV) was performed. Oxygenation and tolerability were assessed during the first 24 hours of NIV., Results: All patients tolerated the helmet well and their oxygenation improved. Two patients developed septic shock and had to be endotracheally intubated during the study period, eight patients survived to be weaned from NIV., Conclusions: NIV delivered via the helmet is effective and may serve as a better tolerated alternative to endotracheal intubation and to NIV via a standard face mask.

Objective: To compare the acute effects of noninvasive pressure support ventilation (NIPSV) in non-COPD patients with acute cardiogenic pulmonary edema (CPE) and severe community-acquired pneumonia (CAP) presenting with a similar hypoxemic respiratory failure and exploring the ensuing impact on outcome. DESIGN. Prospective, observational study. SETTING. Multidisciplinary ICU, regional teaching hospital., Patients: Non-COPD patients with CPE or severe CAP., Measurements and Results: Fifteen patients with CPE and eighteen with CAP were included. Both groups had similar low PaO2/FiO2 ratios at admission; SAPS II, baseline pH(a) were lower in the CPE group than in the CAP group. Within the first NIPSV observation period (60 min), the oxygenation improved significantly in both CPE and CAP-groups; respiratory rate (RR) significantly decreased in the CPE group ( P=0.005), but it remained unchanged in the whole CAP group; heart rate and mean arterial pressure significantly decreased in both groups. One patient (6.6%) in the CPE group and seven patients (38%) in the CAP group were intubated ( P=0.04). The mean total time spent on NIPSV was 9.6+/-6.3 h in the CPE and 37.2+/-36 h in the CAP group ( P=0.01). Unit mortality rate was 6.6% in the CPE and 28% in the CAP group ( P=0.2). Upon inclusion, all but one CAP patients who were subsequently intubated had a bacteremic pneumonia; unit mortality rate was 57% in intubated- and 9% in non-intubated CAP patients ( P=0.05)., Conclusions: NIPSV equally and rapidly improved oxygenation in non-COPD patients with CPE and severe CAP presenting with a similar hypoxemic respiratory failure, but the subsequent outcome was definitely different in the two groups, depending on the nature of the acute lung injury.

Context: Invasive life-support techniques are a major risk factor for nosocomial infection. Noninvasive ventilation (NIV) can be used to avoid endotracheal intubation and may reduce morbidity among patients in intensive care units (ICUs)., Objective: To determine whether the use of NIV is associated with decreased risk of nosocomial infections and improved survival in everyday clinical practice among patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) or hypercapnic cardiogenic pulmonary edema (CPE)., Design and Setting: Matched case-control study conducted in the medical ICU of a French university hospital from January 1996 through March 1998., Patients: Fifty patients with acute exacerbation of COPD or severe CPE who were treated with NIV for at least 2 hours and 50 patients treated with mechanical ventilation between 1993 and 1998 (controls), matched on diagnosis, Simplified Acute Physiology Score II, Logistic Organ Dysfunction score, age, and no contraindication to NIV., Main Outcome Measures: Rates of nosocomial infections, antibiotic use, lengths of ventilatory support and of ICU stay, ICU mortality, compared between cases and controls., Results: Rates of nosocomial infections and of nosocomial pneumonia were significantly lower in patients who received NIV than those treated with mechanical ventilation (18% vs 60% and 8% vs 22%; P<.001 and P =.04, respectively). Similarly, the daily risk of acquiring an infection (19 vs 39 episodes per 1000 patient-days; P =.05), proportion of patients receiving antibiotics for nosocomial infection (8% vs 26%; P =.01), mean (SD) duration of ventilation (6 [6] vs 10 [12] days; P =.01), mean (SD) length of ICU stay (9 [7] vs 15 [14] days; P =.02), and crude mortality (4% vs 26%; P =.002) were all lower among patients who received NIV than those treated with mechanical ventilation., Conclusions: Use of NIV instead of mechanical ventilation is associated with a lower risk of nosocomial infections, less antibiotic use, shorter length of ICU stay, and lower mortality. JAMA. 2000;284:2361-2367.

Objective: Experimental use of noninvasive pressure support ventilation (NIPSV) in patients with severe pulmonary oedema who would have been intubated if noninvasive ventilation were not available., Design: Open, prospective, within patients non comparative study., Setting: Internal intensive care unit (11 beds) at a university hospital., Patients: 29 patients with severe respiratory distress and confirmed pulmonary oedema., Interventions: NIPSV was applied via a tight fitting face mask delivering between 13 and 24 cm H2O inspiratory airway pressure and between 2 and 8 cm H2O expiratory airway pressure., Measurements and Results: One patient required endotracheal intubation. Mean plethysmographic oxygen saturation rose significantly within 30 min from 73.8 +/- 11 to 90.3 +/- 5% while the oxygen supply was reduced from 7.3 +/- 3.7 to 5.1 +/- 3 l/min. Mean pH increased significantly (p < 0.01) from 7.22 +/- 0.1 before NIPSV to 7.31 +/- 0.01 after 60 min of NIPSV. Partial pressure of carbon dioxide was 62 +/- 18.5 mmHg, but decreased significantly within 60 min to 48.4 +/- 11.5 mm Hg. Heart rate and blood pressure established continuously during observation time. Mean duration of NIPSV was 6 h 9 min (range 120 min to 24 h). There were no serious side effects. Four patients died from underlying diseases between 1 and 28 days after NIPSV., Conclusion: NIPSV is a highly effective technique with which to treat patients with severe cardiogenic pulmonary oedema.

Objective: Experimental use of noninvasive pressure support ventilation (NIPSV) in patients with severe pulmonary oedema who would have been intubated if noninvasive ventilation were not available., Design: Open, prospective, within patients non comparative study., Setting: Internal intensive care unit (11 beds) at a university hospital., Patients: 29 patients with severe respiratory distress and confirmed pulmonary oedema., Interventions: NIPSV was applied via a tight fitting face mask delivering between 13 and 24 cm H2O inspiratory airway pressure and 2 to 8 cm H2O expiratory airway pressure., Measurements and Results: One patient required endotracheal intubation. Mean plethysmographic oxygen saturation rose significantly within 30 min from 73.8+/-11 to 90.3+/-5%, while the oxygen supply was reduced from 7.3+/-3.7 to 5.1+/-3 l/min. Mean pH increased significantly (p<0.01) from 7.22+/-0.1 before NIPSV to 7.31+/-0.07 after 60 min of NIPSV. Partial pressure of carbon dioxide was 62+/-18.5 mmHg but decreased significantly within 60 min to 48.4+/-11.5 mm Hg. Heart rate and-blood pressure stabilised continuously during the observation time. Mean duration of NIPSV was 6 h 9 min (range 60 min to 24 h). There were no serious side effects. Four patients died from underlying diseases between 1 and 28 days after NIPSV., Conclusion: NIPSV is a highly effective technique with which to treat patients with severe cardiogenic pulmonary oedema.

A 61-year-old woman with ischemic cardiomyopathy continued to have recurrent episodes of respiratory failure secondary to acute pulmonary edema requiring ventilatory support on each occasion, despite undergoing surgical revascularization and mitral valve replacement. These episodes of acute respiratory failure were successfully averted by using nocturnal nasal continuous positive airway pressure (N-CPAP). Following N-CPAP, she was able to stay home for 207 consecutive days. Although well-designed, controlled studies are needed to validate this observation, nocturnal N-CPAP is a viable and cost effective option that may be considered in a select number of patients with end-stage cardiopulmonary disease.

Non-invasive continuous positive airway pressure (CPAP) seems to decrease the need for intubation in patients with severe cardiogenic pulmonary oedema (CPO) in the intensive care unit. The goals of our study were to delineate indications for CPAP in the emergency department, and to confirm its usefulness in such a setting. We retrospectively assess the evolution of all patients ventilated under CPAP for an acute hypoxaemic respiratory failure over a 1-year period (n = 64 patients). Hypercarbia and respiratory acidosis were present in most patients with CPO (PaCO2 = 54.4+/-22.3 mmHg; pH = 7.27+/-0.13), according to respiratory exhaustion, although initial PaCO2 was low in the pneumonia group. There was a significant improvement of arterial blood gases after 1 hour of ventilation in the CPO group (PaO2 = 254.1+/-121.0 mmHg; PaCO2 = 44.0+/-12.6 mmHg; pH = 7.34+/-0.08; p < 0.0001 for both parameters). In the pneumonia group, oxygenation was also improved but with the persistence of a significant shunt (PaO2 = 157.6+/-84.4 mmHg). Fifty-four patients (84%) were considered as successfully ventilated under CPAP, with no need for intubation and a favourable evolution, mainly in the CPO group. No side effects were reported. In conclusion, CPAP is a useful and easy-to-use ventilatory device in the emergency department. It is now one of our first line treatments during prehospital and emergency care of patients with CPO.

This article reviews the literature of noninvasive positive pressure ventilation (NPPV) in patients with acute respiratory failure. The article divides acute respiratory failure into the categories of primary ventilation failure and oxygenation failure, and examines various diagnostic groups within these categories. Although the use of NPPV for patients with acute respiratory failure of other etiologies requires further study, the authors conclude that there is sufficient evidence to support the use of NPPV in acute, severe exacerbations of chronic obstructive pulmonary disease.

Objectives: Intubation and ventilatory assistance are often required in patients presenting severe hypoxemic respiratory distress, but may be contraindicated in elderly subjects due to an underlying condition. The aim of this study was to assess the feasibility, acceptability and contribution of early assistance with spontaneous positive end-expiratory pressure ventilation for elderly subjects admitted to an emergency unit for acute respiratory distress due to cardiogenic pulmonary edema., Patients and Methods: In our emergency admission unit, all patients with life-threatening hypoxemic respiratory distress are initially assisted with noninvasive spontaneous positive end-expiratory pressure ventilation using a standardized commercial device. We retrospectively analyzed the the files of all patients aged over 70 years who were treated with this standard protocol for cardiogenic pulmonary edema from April 1996 through September 1997., Results: During the study period, 36 patients aged over 70 years required ventilatory assistance according to the standard protocol. Intubation was not reasonable in most of the patients (n = 30). After 1 hour of ventilation, none of the patients developed clinical signs of life-threatening distress. Blood gases demonstrated improved oxygenation (AEPO2 = +184.9 +/- 105.4 mmHg; p < 0.000001). Thirty-two patients were considered to be cured (88.9%) and were discharged; the cardiovascular condition was fatal in 4 patients (11.1%)., Conclusion: The rapid improvement in clinical signs and blood gases as well as the final outcome suggests that early assistance with spontaneous positive end-expiratory pressure ventilation is warranted at admission for elderly patients with respiratory distress due to cardiogenic pulmonary edema. Compared with a control group of hospitalized patients cared for during the preceding year and who were not treated with the standard protocol, we also demonstrated a clear improvement in mortality (11% versus 20%).

We describe a patient with combined meningococcal septicemia and meningitis, cerebral edema and acute respiratory distress syndrome, in whom we balanced the conflicting carbon dioxide strategies for optimal pulmonary and neurological management using jugular oxygen saturation (SjvO2) monitoring to identify the upper limit of "tolerable" hypercapnia. Our observations suggest that significant acidosis was not well tolerated; however, cautious induction of pH down to 7.32 and an arterial carbon dioxide tension (PaCO2) < 5.9 kPa was tolerated acutely without significant cerebral hyperemia. Moreover, with the development of metabolic compensation and normal pH, higher levels of PaCO2 could be permitted. In similar cerebro-pulmonary circumstances we suggest that these findings warrant consideration. Alternatively, invasive monitoring of SjvO2 could be undertaken so that patient-specific criteria for permissive hypercapnia can be determined.

We report the successful outcome of first-line intervention of noninvasive positive pressure ventilation (NPPV) in four patients, three of whom had hypercapnic acute respiratory failure (ARF) and one hypoxaemic ARF, secondary to pulmonary oedema. The clinical condition showed rapid improvement and the NPPV, performed together with aggressive medical treatment, was effective in decreasing the respiratory frequency, and in correcting gas exchange abnormalities within the first 3 h. The average duration of nasal mask ventilation was 11 h (range 6-15 h). The patients were weaned, following ARF, by removing the ventilator whenever inspiratory positive airway pressure (IPAP) was 5 cmH2O. NPPV was applied, by nasal mask, using a bi-level positive airway pressure (BiPAP) delivering pressure support ventilation (PSV). We conclude that application of noninvasive positive pressure ventilation may be effective in correcting gas exchange abnormalities, in relieving respiratory distress and, perhaps, in avoiding endotracheal intubation in selected patients with acute respiratory failure secondary to reversible medical condition such as pulmonary oedema.

We evaluated the efficacy of noninvasive mechanical ventilation (NIMV) in alleviating distress and avoiding intubation in patients with de novo acute respiratory failure complicating primary medical disorders. Eleven consecutive patients with severe respiratory distress were entered. In all patients a decision to intubate on an urgent basis had been made, but NIMV could be initiated within minutes. The patients suffered from acute pulmonary edema (five), sepsis/ARDS (two), status asthmaticus (two), and severe pneumonia (two). Dyspnea score (max=10) was (+/- SD) 8.4 +.- 1.6, scale for accessory muscle use (max=5) was 4.2 +/- 0.7, and respiratory rate was 37.6 +/- 3.8 min -1. Pa CO2, pH, and base excess (BE) were 48 +/- 18 mm Hg, 7.27 +/- 0.13, and -5.5 +/- 7.4, respectively, with five patients showing severe metabolic acidosis (BE < - 10). NIMV was applied using proportional assist ventilation. There were three early failures. These included the two patients with sepsis/ARDS who did not tolerate the mask. One patient failed because Pa CO2 and pH deteriorated despite subjective improvement. The remaining eight patients demonstrated progressive improvement, and none required intubation. The duration of NIMV was 3 h to 2 d. We conclude that when NIMV is made available on a "few minutes" basis, selected patients with severe de novo respiratory distress/failure caused by reversible medical disorders, who would otherwise have been intubated, can be given substantial relief and be spared intubation.

Severe acute pulmonary edema is a medical emergency that requires immediate action on the part of the health care provider. Endotracheal intubation and mechanical ventilation remain the primary method of respiratory support in the most severe cases when respiratory failure ensues. Two cases of respiratory failure resulting from severe acute pulmonary edema are presented in which mechanical ventilation was indicated but the patients were treated instead with noninvasive bilevel positive pressure ventilation, which subsequently reversed their inspiratory failure. The use of noninvasive bilevel positive pressure ventilation in the emergency treatment of respiratory failure secondary to severe acute pulmonary edema is discussed.

The management of patients with respiratory failure from cardiogenic pulmonary edema may require intubation and mechanical ventilation. This provides both ventilatory assistance as well as the beneficial hemodynamic effects of positive intrathoracic pressure. As the need for ventilation is usually short term, noninvasive ventilatory support may be adequate. We report the use of biphasic positive airway pressure by nasal mask (BiPAP system) to successfully manage two patients with respiratory failure due to pulmonary edema.

Positive end expiratory pressure (PEEP) is an accepted treatment for children with acute respiratory failure secondary to restrictive lung diseases. Using a simple technique based on open circuit nitrogen washout, we determined the functional residual capacity (FRC) in 25 ventilated children (age 3 wk-10 y) with acute respiratory failure secondary to restrictive lung disease (pulmonary edema, bilateral pneumonia). FRC measured at a physiologic level of PEEP (2-4 cm H2O) was 45.0 +/- 3.6% (mean +/- SEM; range 12-80%) lower than normal predicted values. At the PEEP level chosen clinically (4-10 cm H2O, mean = 6.0), the FRC was below normal predicted values for nonintubated children by a mean of 31.8% (range 0-73%) (p = 0.0001) and only seven patients (28%) had FRC within 20% below predicted normal values. FRC normalized at PEEP levels of 6-18 cm H2O (mean = 11.6), which was up to 200% above the clinically chosen PEEP level. In six children without lung disease who were ventilated at a PEEP level of 2-4 cm H2O, the FRC was within normal range in two, but significantly higher (by 45%) in the other four. We conclude that FRC in ventilated children with acute restrictive lung disease is significantly lower than normal and the clinically chosen PEEP fails to normalize the FRC in most of the cases.

The effect of 10 cm H2O of positive end-expiratory pressure (PEEP) on pulmonary extravascular water volume (PEWV) was measured in an animal model of noncardiogenic pulmonary edema. Three groups of animals were studied: (1) controls, (2) those given a saline infusion plus alloxan, and (3) those which received saline infusion plus alloxan and PEEP. All animals were ventilated with a constant volume ventilator. Mean PEWV (+/- SEM) in milliliters per gram of dry lung weight was 4.00 +/- 0.21 for group 1, 6.01 +/- 0.70 for group 2, and 5.77 +/- 0.83 for group 3. Mean PEWV increased significantly in both alloxan groups (groups 2 and 3) as compared to the control group (for both, p less than 0.05); however, PEWV did not differ significantly in the group that received PEEP, as compared to the group ventilated without PEEP. Arterial PO2 and airway pressure required to deliver a constant tidal volume did not change significantly in the experimental groups as compared to the control group. It was concluded that PEEP does not decrease lung water content in pulmonary edema caused by damage to fluid-exchanging vessels.

Respiratory failure of different origins often requires therapy with mechanical ventilation and positive end-expiratory pressure (PEEP). These supports are occasionally inadequate if the damage to one lung is significantly more pronounced than that to the other lung. Technical means exist to ventilate each lung independently or to provide a different PEEP to each lung. The findings from nine patients in whom one of these techniques was applied are presented, and advantages and disadvantages are discussed.

We describe continuous positive airway pressure (CPAP) by mask to reduce hypercarbia in two patients who had pulmonary edema due to congestive heart failure. In such patients, beside reducing venous return and filling pressures, CPAP improves compliance and decreases the work of breathing, thereby improving effective ventilation. Hence, CPAP may be useful to combat not only hypoxemia but also hypercarbia that is associated with pulmonary edema.