Comparison of noninvasive positive pressure ventilation with standard medical therapy in hypercapnic acute respiratory failure. Early use of non-invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease on general respiratory wards: a multicentre randomised controlled trial. Noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease. Noninvasive ventilation for acute respiratory failure: a prospective randomised placebo-controlled trial. [Noninvasive positive pressure ventilation for acute respiratory failure in chronic obstructive pulmonary disease in a general respiratory ward]. [Effects of noninvasive positive pressure ventilation on gas exchange and patients' transformation in chronic obstructive pulmonary disease and respiratory failure]. Noninvasive vs. conventional mechanical ventilation in patients with chronic obstructive pulmonary disease after failure of medical treatment in the ward: a randomized trial. Randomised controlled trial of nasal ventilation in acute ventilatory failure due to chronic obstructive airways disease.
To compare the efficacy of standard medical therapy (ST) and noninvasive mechanical ventilation additional to standard medical therapy in hypercapnic acute respiratory failure (HARF).
                Single center, prospective, randomized, controlled study.
                Pulmonary medicine directed critical care unit in a university hospital.
                Between March 1993 and November 1996, 30 HARF patients were randomized to receive ST or noninvasive positive pressure ventilation (NPPV) in addition to ST.
                NPPV was given with an air-cushioned face via a mechanical ventilator (Puritan Bennett 7200) with initial setting of 5 cm H2O continuous positive airway pressure and 15 cm H2O pressure support.
                At the time of randomization, patients in the ST group had (mean+/-SD) PaO2 of 54+/-13 mm Hg, PaCO2 of 67+/-11 mm Hg, pH of 7.28+/-0.02, and respiratory rate of 35.0+/-5.8 breaths/min. Patients in the NPPV group had PaO2 of 55+/-14, PaCO2 of 69+/-15, pH of 7.27+/-0.07, and respiratory rate of 34.0+/-8.1 breaths/min. With ST, there was significant improvement of only respiratory rate (p < 0.05). However, with NPPV, PaO2 (p < 0.001), PaCO2 (p < 0.001), pH (p < 0.001), and respiratory rate (p < 0.001) improved significantly compared with baseline. Six hours after randomization, pH (p < 0.01) and respiratory rate (p < 0.01) in NPPV patients were significantly better than with ST. Hospital stay for NPPV vs ST patients was, respectively, 11.7+/-3.5 and 14.6+/-4.7 days (p < 0.05). One patient in the NPPV group required invasive mechanical ventilation. The conditions of six patients in the ST group deteriorated and they were switched to NPPV; this was successful in four patients, two failures were invasively ventilated.
                This study suggests that early application of NPPV in HARF patients facilitates improvement, decreases need for invasive mechanical ventilation, and decreases the duration of hospitalization. Within the intensive-care unit, non-invasive ventilation (NIV) can prevent the need for intubation and the mortality associated with severe episodes of chronic obstructive pulmonary disease (COPD). The aim of this study was to find whether the introduction of NIV, early after the admission on a general respiratory ward, was effective at reducing the need for intubation and the mortality associated with acute exacerbations of COPD.
                We did a prospective multicentre randomised controlled study comparing NIV with standard therapy in patients with mild to moderate acidosis. NIV was administered on the ward with a simple non-invasive ventilator and a standardised predefined protocol. Patients were recruited from 14 UK hospitals over 22 months.
                236 patients were recruited, 118 received standard therapy alone and 118 additional NIV. The two groups had similar characteristics at enrolment. The use of NIV significantly reduced the need for intubation as defined by the failure criteria. 32/118 (27%) of the standard group failed compared with 18/118 (15%) of the NIV group (p=0.02). In-hospital mortality was also reduced by NIV, 24/118 (20%) died in the standard group compared with 12/118 (10%) in the NIV group (p=0.05). In both groups pH, PaCO2, and respiratory rate improved at 4 h (p<0.01). However, NIV led to a more rapid improvement in pH in the first hour (p=0.02) and a greater fall in respiratory rate at 4 h (p=0.035). The duration of breathlessness was also reduced by NIV (p=0.025).
                The early use of NIV for mildly and moderately acidotic patients with COPD in the general ward setting leads to more rapid improvement of physiological variables, a reduction in the need for invasive mechanical ventilation (with objective criteria), and a reduction in in-hospital mortality. In patients with acute exacerbations of chronic obstructive pulmonary disease, noninvasive ventilation may be used in an attempt to avoid endotracheal intubation and complications associated with mechanical ventilation.
                We conducted a prospective, randomized study comparing noninvasive pressure-support ventilation delivered through a face mask with standard treatment in patients admitted to five intensive care units over a 15-month period.
                A total of 85 patients were recruited from a larger group of 275 patients with chronic obstructive pulmonary disease admitted to the intensive care units in the same period. A total of 42 were randomly assigned to standard therapy and 43 to noninvasive ventilation. The two groups had similar clinical characteristics on admission to the hospital. The use of noninvasive ventilation significantly reduced the need for endotracheal intubation (which was dictated by objective criteria): 11 of 43 patients (26 percent) in the noninvasive-ventilation group were intubated, as compared with 31 of 42 (74 percent) in the standard-treatment group (P < 0.001). In addition, the frequency of complications was significantly lower in the noninvasive-ventilation group (16 percent vs. 48 percent, P = 0.001), and the mean (+/- SD) hospital stay was significantly shorter for patients receiving noninvasive ventilation (23 +/- 17 days vs. 35 +/- 33 days, P = 0.005). The in-hospital mortality rate was also significantly reduced with noninvasive ventilation (4 of 43 patients, or 9 percent, in the noninvasive-ventilation group died in the hospital, as compared with 12 of 42, or 29 percent, in the standard-treatment group; P = 0.02).
                In selected patients with acute exacerbations of chronic obstructive pulmonary disease, noninvasive ventilation can reduce the need for endotracheal intubation, the length of the hospital stay, and the in-hospital mortality rate. The aim of the present study was to clarify whether the known effects of noninvasive positive-pressure ventilation (NPPV) in patients with respiratory failure are real or due to placebo effects and whether early application of NPPV in the emergency department leads to rapid improvement of the patients condition and outcome. A prospective randomised placebo-controlled study was conducted in 20 patients with severe acute respiratory failure (ARF) secondary to an acute exacerbation of chronic obstructive pulmonary disease (COPD) or acute pulmonary oedema, not improving under conventional medical therapy and on the edge of intubation. Patients received either conventional medical therapy plus two-level NPPV (hi-level NPPV) or conventional medical therapy plus "placebo" NPPV. The main outcome measures involved the need for endotracheal intubation in the bi-level NPPV arm and in the placebo arm after crossing over to active NPPV. Morbidity, length of stay, mortality and the effect of the ventilatory mode on clinical, arterial-blood gas parameters, and the sternocleidomastoid muscles electromyogram (EMG) activity were also measured. The 10 patients in the active NPPV group rapidly improved and none needed intubation. Placebo NPPV resulted in no change in the clinical condition of patients that continued to worsen and the 10 patients were crossed over to active NPPV. Three patients were intubated. No differences in terms of morbidity, length of stay or mortality between the two groups were observed. Active NPPV (but not placebo NPPV) led to a rapid and significant improvement in the clinical parameters, pH and the carbon dioxide tension in arterial blood and to a decrease in respiratory frequency and sternocleidomastoid EMG activity. Early application of bi-level noninvasive positive-pressure ventilation in patients with severe acute respiratory failure, due to chronic obstructive pulmonary disease and acute pulmonary oedema, leads to a rapid improvement in clinical status and blood gases. Noninvasive positive-pressure ventilation had no placebo effect. In patients with acute exacerbations of chronic obstructive pulmonary disease (COPD), noninvasive ventilatory support (NPPV) with bilevel positive airway pressure (BiPAP) may improve clinical and physiological parameters. The present study used a randomized, prospective design to evaluate the possible benefits of NPPV plus standard therapy versus standard therapy alone in patients admitted with acute hypercapnic respiratory failure in a respiratory unit of a tertiary hospital.
                Forty-one patients were included in the study. Of them, 20 were randomly allocated to receive NPPV with a standard mask connected to a BiPAP ventilatory assist device (Respironics Inc, Murrysville, PA) and 21 to standard therapy. Both groups had similar characteristics upon their admission in the hospital.
                The use of noninvasive ventilation significantly reduced the respiratory rates and improved the conscious level within the first 2 h (p < 0.001). There were significant differences in PaCO2 and pH (p < 0.05) at 6 h of treatment. The need for intubation was 5% in the NPPV group vs 14% in the control group. The length of hospital stay was significantly shorter in the NPPV group (7 vs 10 days; p < 0.01). Nasal NPPV was well tolerated and complications were uncommon and mild.
                Early use of noninvasive ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease leads to a more rapid improvement of physiological variables. Moreover, it is possible to apply this treatment in a general respiratory ward. This paper was to observe the effects of noninvasive positive pressure ventilation (NPPV) on gas exchange and patients' transformation and to evaluate their clinical value.
                Patients were randomly treated by either NPPV, or conventional medicine. The arterial blood gas readings, heart rates (HR), and respiratory rates (HR) were obtained at admission after the treatment. It was necessary to intubate when the clinical deterioation was marked by PaCO2 > 70 mmHg, PaCO2 gradually increasing 5-10 mmHg, pH decreasing 0.05-0.1 or mental obstacle, or PaO2 < 45 mmHg.
                NPPV significantly decreased the PaCO2 level, HR, and RR, significantly increased the PaO2 level, and also decreased the opportunity of intubation.
                The results suggest that NPPV can improve the gas exchange and reduce the need of intubation in COPD patients with acute respiratory failure. We conducted a randomized prospective study comparing noninvasive positive pressure ventilation (NPPV) with conventional mechanical ventilation via endotracheal intubation (ETI) in a group of patients with chronic obstructive pulmonary disease who failed standard medical treatment in the emergency ward after initial improvement and met predetermined criteria for ventilatory support.
                Prospective randomized study in a university hospital 13-bed general ICU.
                Forty-nine patients were randomly assigned to receive NPPV (n=23) or conventional ventilation (n=26).
                both NPPV and conventional ventilation significantly improved gas exchanges. The two groups had similar length of ICU stay, number of days on mechanical ventilation, overall complications, ICU mortality, and hospital mortality. In the NPPV group 11 (48%) patients avoided intubation, survived, and had a shorter duration of ICU stay than intubated patients. One year following hospital discharge the NPPV group had fewer patients readmitted to the hospital (65% vs. 100%) or requiring de novo permanent oxygen supplementation (0% vs. 36%).
                The use of NPPV in patients with chronic obstructive pulmonary disease and acute respiratory failure requiring ventilatory support after failure of medical treatment avoided ETI in 48% of the patients, had the same ICU mortality as conventional treatment and, at 1-year follow-up was associated with fewer patients readmitted to the hospital or requiring for long-term oxygen supplementation. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1503-3). Acute exacerbations of chronic obstructive airways disease (COAD) are a common cause of admission to hospital, and have a high mortality. Nasal intermittent positive pressure ventilation (NIPPV) has been used successfully in patients with respiratory failure due to neuromuscular and skeletal disorders, but the outcome of treatment in patients with COAD is less well known. We carried out a prospective randomised controlled trial of conventional treatment versus conventional treatment plus NIPPV, in 60 patients with acute ventilatory failure due to exacerbations of COAD. For the NIPPV group there was a rise in pH, compared with a fall in the controls (mean difference of change between the groups 0.046 [95% CI 0.06-0.02, p < 0.001]), and a larger fall in PaCO2 (mean difference in change between the groups 1.2 kPa [95% CI 0.45 to 2.03, p < 0.01]). Median visual analogue scores over the first 3 days of admission showed less breathlessness in the NIPPV group (2.3 cm [range 0.1-5.5]) than in the control group (4.5 cm [range 0.9-8.8]) (p < 0.025). Survival rates at 30 days were compared for intention-to-treat and efficacy populations. In the efficacy mortality comparison, mortality in the NIPPV group was reduced: 1/26 vs 9/30 (relative risk = 0.13, CI = 0.02-0.95, p = 0.014). This effect was less in the intention-to-treat analysis: 3/30 vs 9/30 (relative risk = 0.33, CI = 0.10-1.11, p = 0.106). In patients with acute ventilatory failure due to COAD who received NIPPV there was a significant rise in pH, a reduction in PaCO2 and breathlessness, and reduced mortality.
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.