Effects of partial liquid ventilation on cerebral blood flow and cerebral metabolism in neonatal lambs.
OBJECTIVE
Liquid ventilation is a promising therapy for respiratory failure. The effects of perfluorochemical on cardiac output have not been well described. The purpose of this study was to compare cerebral blood flow (Q(CAROTID)) and cerebral metabolic rates (CMR) during conventional ventilation (CV) and partial liquid ventilation (PLV).


METHODS
Five 2-week-old lambs underwent tracheostomy and central venous, aortic, and postcerebral venous catheter placement. Doppler flow probes were placed around the common ovine trunk, and the lambs underwent CV for 1 hour. Ventilation was adjusted to maintain physiologic blood gases. Pre- and postcerebral blood gas, glucose, and lactate samples were obtained every 15 minutes. Perfluorodecalin then was instilled endotracheally. The lambs underwent 1 hour of PLV with similar sampling. Data were analyzed using the Wilcoxon matched pairs test, significance at P </=.05.


RESULTS
The authors observed no difference in mean Q(CAROTID) or carotid vascular resistance between CV and PLV (P =.35 and.34, respectively). The CMR of oxygen, glucose, and lactate were calculated using the Fick principle. CMR was unchanged between modes (P =.5).


CONCLUSIONS
PLV did not adversely alter Q(CAROTID) or CMR in lambs, implying that this mode of ventilation should be safe in neonatal patients at risk for neurologic injury.
Dimmitt
Reed A
RA
Division of Neonatal and Developmental Medicine, Department of Pediatrics; Stanford University School of Medicine, Stanford, California, USA.
Beckman
Sarah A
SA
Halamek
Louis P
LP
Moss
R Lawrence
RL
Mickas
Nick A
NA
Falco
Daniel A
DA
Chubb
Christopher
C
Skarsgard
Erik D
ED
D000403:Airway Resistance; D000818:Animals; D000831:Animals, Newborn; D001784:Blood Gas Analysis; D001921:Brain / Q000378:metabolism*; D002339:Carotid Arteries / Q000502:physiology; D002405:Catheterization, Central Venous; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006801:Humans; D021061:Liquid Ventilation / Q000009:adverse effects*; D010101:Oxygen Consumption / Q000502:physiology; D012039:Regional Blood Flow; D012756:Sheep; D014139:Tracheostomy; D014655:Vascular Resistance