Prone positioning, systemic hemodynamics, hepatic indocyanine green kinetics, and gastric intramucosal energy balance in patients with acute lung injury.
OBJECTIVE
To investigate the effects of prone positioning on systemic hemodynamics, intra-abdominal pressure (IAP), plasma disappearance rate of indocyanine green (PDR(ICG)), and gastric intramucosal to arterial PCO2 difference (Pi-aCO2).


METHODS
Prospective randomized study in the intensive care unit of a university hospital.


METHODS
12 mechanically ventilated, hemodynamically stable patients with acute lung injury.


METHODS
Positioning supine and prone for 3 h in random order.


METHODS
Systemic hemodynamics were determined by transpulmonary double-indicator dilution technique using an integrating fiberoptic monitoring system. The same monitoring system was used to measure PDR(ICG). IAP was measured in the urinary bladder and gastric intramucosal PCO2 was evaluated by automated recirculation gas tonometry.


RESULTS
IAP increased from 10 +/-3 in the supine to 13+/-4 mmHg in the prone position. Cardiac index increased from 3.8+/-0.9 (supine) to 4.2+/-0.6 l/m(2) per minute (prone), mean arterial pressure from 75+/-10 (supine) to 81+/-11 mmHg (prone), PaO2/FIO2 from 194+/-66 (supine) to 269+/-68 mmHg (prone), and oxygen delivery from 558+/-122 (supine) to 620+/-74 ml/m(2) per minute (prone). No other parameters, including PDR(ICG) and Pi-aCO2, differed between the two positions.


CONCLUSIONS
Prone positioning in mechanically ventilated patients with acute lung injury, despite a small increase in IAP, does not negatively affect the hepatic capacity to eliminate ICG and gastric intramucosal energy balance when systemic blood flow and oxygenation are improved.
Hering
Rudolf
R
Department of Anesthesiology and Intensive Care Medicine, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. hering@uni-bonn.de
Vorwerk
Ralph
R
Wrigge
Hermann
H
Zinserling
Jörg
J
Schröder
Stefan
S
von Spiegel
Tilman
T
Hoeft
Andreas
A
Putensen
Christian
C
D018806:APACHE; D000293:Adolescent; D000328:Adult; D000368:Aged; D004396:Coloring Agents; D004734:Energy Metabolism; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006439:Hemodynamics; D006801:Humans; D007208:Indocyanine Green / Q000493:pharmacokinetics*; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016684:Prone Position; D012128:Respiratory Distress Syndrome / Q000145:classification / Q000628:therapy*; D016683:Supine Position
D004396:Coloring Agents; D007208:Indocyanine Green