[1999]PARTIAL LIQUID VENTILATION: PHYSIOLOGIC DIFFERENCES BETWEEN FRC AND LOW DOSE AMOUNTS WITH EXOGENOUS SURFACTANT.
Patricia A. Meyers RRT, JM Manaligod MD, EM Bendel-Stenzel MD, DR Bing RRT, SC Simonton MD, MC Mammel MD. Infant Pulmonary Research Center, Children's Hospital-St. Paul, Minnesota and Dept. Of Pediatrics, University of Minnesota, Minneapolis, MN.
Introduction: Does low dose partial liquid ventilation (PLV) with perflubron (LiquiVent
̉
) and surfactant (Survanta
̉
; S) provide the same level of improvement in lung injured animals as FRC dose with S. We evaluated physiologic responses in 32 surfactant depleted newborn piglets. Method: 32 newborn piglets were sedated, paralyzed, and ventilated using a volume target of 12cc/kg. We induced lung injury, defined as PaO2<60 torr at FiO2 1.0 and lung compliance reduction by > 30%, with repeated saline lavage. After stabilization on CV (Dräger Babylog
̉
), we randomized animals to 4 groups of 8 each: conventional ventilation (CV)+S+PLV to FRC(28.5±5.7 mL/kg), high frequency ventilation (HFV; SensorMedics 3100)+S, HFV+S+low PLV (10 mL/kg) and HFV+S+PLV to FRC(27.5±6.8mL/kg) and ventilated for 20 hrs. PLV animals had perfluorocarbon instilled intratracheally. Evaporative loss were replaced hourly by assessing meniscus in ET tube, HFV+S+low PLV received 3ml/kg/hr replacement. We measured arterial blood gases, arterial and central venous pressures, heart rates, and calculated A/a ratio and OI every hour. Ventilators were adjusted as in clinical use. All techniques provided similar physiologic stability. HFV required higher Paw than CV.
3hr
8hr
12hr
16hr
20hr
CV+S+PLV
Paw
14*
13*
13*
12*
12**
pH
7.36
7.37
7.34
7.36
7.35
a/A
0.39
0.42
0.39
0.46
0.44
HFV+S
Paw
18
15
15
14?
16
pH
7.36
7.36
7.33
7.34
7.34
a/A
0.41
0.45
.48
0.42
0.43
HFV+S+lowPLV
Paw
18
15
15
17
17
pH
7.36
7.36
7.34
7.34
7.38
a/A
0.46
0.44
.52
0.47
0.44
HFV+S+PLV
Paw
19
17
16
16
15
pH
7.36
7.39
7.34
7.4
7.37
a/A
0.41
0.46
.40
0.47
0.46
*p<0.05 CMV+S+PLV vs all; **p<0.05 CMV+S+PLV vs HFV+S+low PLV ?p<0.05 HFV+S vs HFV+S+low PLV
Conclusions: Gas exchange and cardiovascular stability was not enhanced by the combination of HFV+PLV. HFV+S+low PLV was not different from other PLV groups.
