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Therapeutics

Noninvasive positive-pressure ventilation was as effective as conventional mechanical ventilation and had fewer complications

ACP J Club. 1999 Jan-Feb;130:10. doi:10.7326/ACPJC-1999-130-1-010

Related Content in the Archives
Noninvasive positive-pressure ventilation reduced the need for intubation in acute respiratory failure


Source Citation

Antonelli M, Conti G, Rocco M, et al. A comparison of noninvasive positive-pressure ventilation and conventional mechanical ventilation in patients with acute respiratory failure. N Engl J Med. 1998 Aug 13;339:429-35.


Abstract

Question

Is noninvasive positive-pressure ventilation (NIPPV) by face mask as effective as mechanical ventilation (MV) with endotracheal intubation for hypoxemic respiratory failure?

Design

Randomized controlled trial with follow-up to hospital discharge.

Setting

An intensive care unit (ICU) in a university hospital in Rome, Italy.

Patients

64 patients with acute respiratory failure despite aggressive medical management. Exclusion criteria were emergency intubation, severe hemodynamic instability, respiratory arrest, respiratory failure caused by neurologic disease or asthma, chronic obstructive pulmonary disease (COPD), encephalopathy, > 2 new organ failures, immunosuppressive therapy, or facial deformities. Follow-up was complete.

Intervention

32 patients were allocated to NIPPV using a clear, full-face mask with an inflatable soft cushion seal and foam spacer. NIPPV was initiated using a pressure-support protocol. Conventional MV in 32 patients began with endotracheal intubation; the assist-control mode was changed to intermittent mandatory ventilation with pressure support when patients were breathing spontaneously. Intubation criteria were specified a priori.

Main outcome measures

Complications included abnormal blood gas values, pneumonia, sepsis, and sinusitis. Secondary outcomes were survival and duration of MV and ICU stay.

Main results

10 patients in the NIPPV group required intubation. Blood gas values were similar in both groups. Patients in the NIPPV group had a shorter ICU stay (9 v 16 d, P = 0.04), fewer severe complications (P = 0.02), and less pneumonia or sinusitis (P = 0.003) than patients who had endotracheal MV (Table). The groups did not differ for survival (53% in the MV group vs 72% in the NIPPV group [ P = 0.2]). Among patients who survived, those in the NIPPV group spent less time on MV (3 v 6 d, P = 0.006) and had a shorter stay in the ICU (7 vs 14 d, P = 0.002).

Conclusion

Noninvasive positive-pressure ventilation was as effective as intubation and mechanical ventilation in improving gas exchange and was associated with fewer complications and a shorter duration of mechanical ventilation and intensive care unit stay.

Source of funding: Not stated.

For correspondence: Dr. M. Antonelli, Istituto di Anestesiologia e Rianimazione, Università La Sapienza, Policlinico Umberto I, Viale del Policlinico 155, 00161 Rome, Italy. FAX 39-6-4461967.


Table. Noninvasive positive-pressure ventilation (NIPPV) vs mechanical ventilation (MV) with intubation for patients with acute hypoxemic respiratory failure*

Outcomes at discharge NIPPV MV RRR (95% CI) NNT (CI)
Complications 37.5% 65.6% 42.9% (6.8 to 66.7) 4 (2 to 27)
Pneumonia or sinusitis 3.1% 31.3% 90% (45 to 98) 4 (2 to 9)

*Abbreviations defined in Glossary; RRR, NNT, and CI calculated from data in article.


Commentary

The design of this randomized trial differs from that of other trials of NIPPV because of the application of the intervention after patients developed severe respiratory failure requiring ventilatory support. In previous studies, patients with less severe respiratory failure were randomly assigned to NIPPV or "standard care" to avoid the need for endotracheal intubation and MV. In 1 such trial, NIPPV resulted in fewer complications and improved survival among patients with respiratory failure and COPD (1). A recent meta-analysis of trials of NIPPV reported benefit of early NIPPV only for patients with acute exacerbations of COPD (2).

Before this trial by Antonelli and colleagues, the only study to examine patients without COPD did not find any additional benefit to the earlier use of NIPPV with respect to intubation or mortality (3). The study by Antonelli and colleagues, however, found lower rates of sinusitis and pneumonia and a shorter length of ICU stay in patients with acute hypoxemic respiratory failure who required MV but were managed with NIPPV. Because blinding a study of this design is so difficult, protocols for ventilation and criteria for intubation were carefully specified and were applied by bedside clinicians.

In summary, it is still unclear whether early NIPPV in patients who do not have COPD prevents the need for intubation or whether specific subgroups of patients preferentially benefit from it. This trial, however, suggests that for patients presenting in severe respiratory distress, NIPPV may lead to more favorable outcomes than conventional MV, at least in the hands of experienced practitioners in a setting where this technology can be safely administered and monitored.

Sean P. Keenan, MD
St. Paul's HospitalVancouver, British Columbia, Canada


References

1. Brochard L, Mancebo J, Wysocki M, et al. Noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease. N Engl J Med. 1995;333:817-22.

2. Keenan SP, Kernerman PD, Cook DJ, et al. Effect of noninvasive positive pressure ventilation on mortality in patients admitted with acute respiratory failure: a meta-analysis. Crit Care Med. 1997;25:1685-92.

3. Wysocki M, Tric L, Wolff MA, et al. Noninvasive pressure support ventilation in patients with acute respiratory failure. A randomized comparison with conventional therapy. Chest. 1995;107:761-8.