D. Easa et al., CONTINUOUS NEGATIVE EXTRATHORACIC PRESSURE VERSUS POSITIVE END-EXPIRATORY PRESSURE IN PIGLETS AFTER SALINE LUNG LAVAGE, Pediatric pulmonology, 17(3), 1994, pp. 161-168
Recent reports have suggested that substituting continuous negative ex
trathoracic pressure (CNEP) for positive end-expiratory pressure (PEEP
) may result in clinical benefits to infants with pulmonary disease. O
ther studies have suggested potential hemodynamic advantages. We compa
red the effects of CNEP and PEEP in 13 mechanically ventilated newborn
piglets after acute lung injury induced by saline lavage. The piglets
were instrumented, saline-lavaged, and exposed to 15 minute periods o
f incremental CNEP (-3, -6, -9, -12 cmH(2)O) (n = 7) or PEEP (3, 6, 9,
12 cmH(2)O) (n = 6). We measured and/or calculated dynamic lung compl
iance (C-Ldyn), lung resistance (R(L)), end-expiratory lung volume (EE
LV), blood gases, cardiac output (CO), heart rate (HR), transmural vas
cular pressures, and pulmonary and systemic vascular resistance. Pulmo
nary function abnormalities after saline lavage included decreased P-a
O2, C-Ldyn, EELV, and increased P-aCO2 and R(L) (P < 0.05). Except for
decreased CO, lung inflation with both CNEP and PEEP resulted in larg
e increases in P-aO2 without major pulmonary or hemodynamic effects. O
ther than differences in EELV at 3, 6 and 9 cmH(2)O distending pressur
e, there were no differences in pulmonary function or hemodynamics bet
ween sequences of incremental CNEP and PEEP. We conclude that CNEP and
PEEP are physiologically equivalent in this model of acute lung injur
y. (C) 1994 Wiley-Liss, Inc.