Effect of pulmonary artery pressure on extravascular lung water in an experimental model of acute lung injury.

BACKGROUND: Lung edema can be influenced by hemodynamic changes in pulmonary circulation. The aim of this study was to evaluate, in an experimental model of acute lung injury, the effect on extravascular lung water (EVLW) of an increase in pulmonary artery pressure (Ppa) without changes in cardiac output and wedge pressure. METHODS: Lung edema was produced by an intravenous oleic acid infusion in mixed-breed pigs weighing 25-31 kg, which, after 20 min, were randomly assigned to a control group (100% FiO(2)) (n = 6) or a high Ppa group (21% FiO(2)) (n = 7). An increase in pulmonary artery pressure of at least 40% over baseline was produced in the high Ppa group by alveolar hypoxia. Hemodynamic, ventilatory and gas exchange parameters were collected at regular intervals. Pulmonary, wedge and capillary pressures were measured with a pulmonary artery catheter and the occlusion technique. EVLW was calculated gravimetrically. RESULTS: At 240 min, both gravimetric-measured EVLW and mean pulmonary artery pressures were significantly higher (P < 0.05) in high Ppa animals vs. controls (12.06 +/- 4.21 vs. 7.98 +/- 2.46 ml/kg and 39.0 +/- 1.3 vs. 26.6 +/- 4.7 mmHg, respectively). Cardiac output (6.8 +/- 2.5 vs. 7.3 +/- 1.3) and pulmonary wedge pressures (9.2 +/- 1.7 vs. 9.4 +/- 2.8 mmHg) were similar. A difference was detected in pulmonary capillary pressures [17.0 +/- 3.3 (high Ppa) vs. 13.8 +/- 2.7 mmHg (controls)] but did not reach statistical significance. CONCLUSIONS: In this model, an increase in pulmonary artery pressure by alveolar hypoxia produces an increase in extravascular lung water, probably related to changes in pulmonary capillary pressures.

Gestación interrumpida del segundo trimestre complicada con miocardiopatía dilatada / A pregnancy interrupted in the second trimester complicated by dilated myocardopathy

Presentamos un caso de miocardiopatía dilatada asociada a interrupción de la gestación en la semana 19, que requirió la evacuación inmediata de los restos ovulares mediante microcesárea ante el deterioro progresivo cardiorrespiratorio desde el ingreso. Se llegó al diagnóstico tras no encontrar causa evidenciable alguna a pesar de toda la batería de pruebas de laboratorio realizadas. El ecocardiograma reveló la dilatación del ventrículo izquierdo con hipocinesia generalizada y disfunción sistólica. La paciente precisó de tratamiento intensivo similar al de la insuficiencia cardíaca para estabilizarla. La evolución favorable fue sorprendente y a los 6 meses no presenta secuelas (AU)

We report a case of dilated cardiomyopathy linked to a missed abortion in the 19th week, requiring immediate evacuation of products of pregnancy by means of a microcaesarean because of cardiorespiratory deterioration following admission to hospital. Diagnosis was made excluding other possibilities in spite of extensive laboratory tests, as there was no obvious cause for this. Echocardiogram showed left ventricular dilatation with general hypokinesis and systolic dysfunction. The patient required intensive care to stabilize her cardiac insufficiency. Surprisingly, her evolution was favourable, and after six months she has no sequelae (AU)

Effect of a catecholamine-induced increase in cardiac output on extravascular lung water.

OBJECTIVE: To determine the influence of dopamine- and dobutamine-induced increases in cardiac output on the extravascular lung water in an experimental model of pulmonary edema. DESIGN: Animal experimental study. SETTING: Animal experimental laboratory of a tertiary hospital. SUBJECTS: Mixed-race pigs (n = 20) weighing 28-32 kg. INTERVENTIONS: After the animals were anesthetized and tracheotomized, they were injected with 0.1 mL/kg of oleic acid, producing a pulmonary edema by increased permeability. The animals then were randomized into two groups: Group I (n = 10) received no medication to alter cardiac output and remained on mechanical ventilation during the 240 mins of the experiment; group II (n = 10) received a continuous infusion of dopamine and dobutamine to produce a cardiac output increase of >or=30% the basal value and underwent the same mechanical ventilation regimen as group I. MEASUREMENTS AND MAIN RESULTS: Hemodynamic and respiratory variables were measured at 0 (baseline) and 30, 60, 120, 180, and 240 mins after the infusion of oleic acid. At 30 mins, the cardiac output of group II (5.40 +/- 0.94 L/min) was significantly (p < .005) higher than that of group I (3.65 +/- 1.02 L/min), and a similar significant increase was recorded at all measurement times until the end of the experiment. The mean pulmonary arterial pressure was similar in both groups except that at 240 mins it was significantly higher in group I (normal cardiac output) than in group II (high cardiac output; 34.9 +/- 7.9 mm Hg vs. 27.2 +/- 3.8 mm Hg, p = .01). The extravascular lung water was calculated by gravimetric method after the death of the animal. The extravascular lung water of group I (13.8 +/- 3.6 mL/kg) did not significantly differ from that of group II (11.5 +/- 4.0 mL/kg). CONCLUSIONS: An increase in cardiac output experimentally produced by the infusion of dopamine and dobutamine does not modify the amount of extravascular lung water.

PEEP and low tidal volume ventilation reduce lung water in porcine pulmonary edema.

This study analyzed the effect of both positive end-expiratory pressure (PEEP) and reduction in tidal volume (VT) on extravascular lung water (EVLW) in a permeability model of pulmonary edema. Immediately after producing a pulmonary edema with oleic acid, 21 pigs were randomized into three groups. Group I (n = 8): PEEP of 0 cm H2O (ZEEP), VT of 12 ml/kg; Group II (n = 6): PEEP of 10 cm H2O, VT of 12 ml/kg; Group III (n = 7): PEEP of 10 cm H2O, VT of 6 ml/kg. EVLW was measured by the double indicator method (DI) at baseline (time 0) and after 30, 60, 120, 180, and 240 min and by the gravimetric method (G) at 240 min. Both methods correlated excellently (r = 0.94, p < 0.0001). EVLW-DI was significantly less with PEEP application (Group II versus Group I) at 180 min and thereafter. Likewise, EVLW-DI was less throughout the experimental period with reduced VT once PEEP was applied (Group III versus Group II). EVLW-G was less in Group II than in Group I at 16.3 +/- 2.7 and 23.2 +/- 4.2 ml/kg, respectively (p < 0.0001), and less in Group III than in Group II at 10.7 +/- 0.9 and 16.3 +/- 2.7 ml/kg (p < 0.0001). We conclude that early application of 10 cm H2O of PEEP reduces EVLW in permeability pulmonary edema. The lowering of VT reduced EVLW even further.