NONINVASIVE POSITIVE-PRESSURE VENTILATION IN ACUTE RESPIRATORY-DISTRESS WITHOUT PRIOR CHRONIC RESPIRATORY

We evaluated the efficacy of noninvasive mechanical ventilation (NIMV) in alleviating distress and avoiding intubation in patients with de n ovo acute respiratory failure complicating primary medical disorders. Eleven consecutive patients with severe respiratory distress were ente red. In all patients a decision to intubate on an urgent basis had bee n made, but NIMV could be initiated within minutes. The patients suffe red from acute pulmonary edema (five), sepsis/ARDS (two), status asthm aticus (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, an d 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. T here were three early failures. These included the two patients with s epsis/ARDS who did not tolerate the mask. One patient failed because P a-CO2 and pH deteriorated despite subjective improvement. The remainin g eight patients demonstrated progressive improvement, and none requir ed intubation. The duration of NIMV was 3 h to 2 d. We conclude that w hen NIMV is made available on a ''few minutes'' basis, selected patien ts with severe de novo respiratory distress/failure caused by reversib le medical disorders, who would otherwise have been intubated, can be given substantial relief and be spared intubation.