PULMONARY MECHANICS AND HEMODYNAMICS IN A MECONIUM ASPIRATION (MAS) LAMB MODEL TREATED WITH PARTIAL LIQUID VENTILATION (PLV) AND NITRIC OXIDE (NO).245

MAS is associated with surfactant inactivation and pulmonary hypertension. We studied the MAS newborn lamb response to PLV with inhaled NO. Term lambs were delivered by C-section, intubated and instrumented. Lambs received 2-2.5 ml/kg of 20% human meconium slurry prior to the first breath. All lambs received conventional ventilation (CV) on F_IO₂ 1.0 and PEEP of 3-4 cmH₂O. Respiratory rate and pressures were adjusted to achieve P_aCO₂ 35-45 mmHg. At 1 hour lambs received either PLV with perflubron (LiquiVent ®;n=3) or CV(n=5). At 4 hours lambs received 80 ppm NO for 10 minutes. Oxygen Index (OI) was lower and dynamic compliance was higher in the PLV group (Δ) as compared to the CV (□) group. Pulmonary arterial pressure (P_PA) and pulmonary vascular resistance(PVR) were elevated in both groups. No difference was noted in heart rate, aortic and left atrial pressures, pH, and PaCO₂. At 4 hours inhaled NO decreased P_PA and PVR in both groups. Table We conclude that PLV improved lung function, and NO decreased PVR in this MAS model. Funded in part by Alliance Pharmaceutical Corp.Figure

Table 1

Figure 1