EFFECT OF NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE ON PULMONARY-EDEMA COMPLICATING ACUTE MYOCARDIAL-INFARCTION

Cardiogenic pulmonary edema is a frequent cause of reparatory failure. We investigated the effects of nasal continuous positive airway press ure (CPAP) in patients with severe pulmonary edema associated with acu te myocardial infarction. Twenty-nine consecutive patients were divide d into 3 groups: firstly, 7 intubated patients who received mechanical ventilation at study entry comprised the intubation group. The rest o f the patients were randomly assigned to either of the following 2 gro ups: 11 patients who received oxygen plus CPAP delivered by a nasal ma sk (CPAP group), and 11 patients who received oxygen only via face mas k (oxygen group). All patients in the intubation group had cardiogenic shock. Two patients (18%) in the CPAP group and 8 patients (73%) in t he oxygen group required mechanical ventilation with endotracheal intu bation (p=0.03). The hospital mortality rate in the CPAP group (9%) wa s significantly lower than the oxygen group (64%, p=0.02). The pulmona ry artery wedge pressure and heart rate were significantly lower in th e CPAP group than in the oxygen group 24 h after study entry (p<0.05 a nd p<0.01). The mean pulmonary artery pressure 48 h after study entry was 18+/-5 mmHg in the CPAP group and 25+/-8 mmHg in the oxygen group (p<0.05). The PaO2/FiO2 ratio increased in the intubation group (168+/ -69 to 240+/-57, p<0.05) and the CPAP group (137+/-17 to 253+/-67, p<0 .01) 24 h after study entry. Arterial plasma endothelin-l concentratio ns decreased significantly earlier in the CPAP group than in the oxyge n group (p<0.05). In patients without cardiogenic shock, nasal CPAP le ad to an early improvement in oxygenation and hemodynamics, and decrea sed the mortality rate. Early and active respiratory management is rec ommended in patients with pulmonary edema associated with acute myocar dial infarction.