Albumin resuscitation improves ventricular contractility and myocardial tissue oxygenation in rat endotoxemia.
OBJECTIVE
Fluid resuscitation to improve delivery of oxygen to vital organs is a principal clinical intervention for septic patients. We previously reported that albumin resuscitation in rat endotoxemia improved contractility in isolated cardiomyocytes, but whether this effect occurs in vivo is unknown. We hypothesized that albumin resuscitation would improve decreased ventricular contractility and myocardial tissue oxygenation in vivo.


METHODS
Randomized, controlled, prospective animal study.


METHODS
University animal laboratory.


METHODS
Male Sprague-Dawley rats (250-350 g).


METHODS
Rats were randomized into three groups: control with no lipopolysaccharide (n = 8), lipopolysaccharide (10 mg/kg) without albumin resuscitation (n = 8), and lipopolysaccharide with albumin resuscitation (n = 6). Five hours after lipopolysaccharide injection, animals were resuscitated with 10 mL/kg 5% rat albumin in 0.9% saline. Six hours after 10 mL/kg lipopolysaccharide, a pressure-volume conductance catheter (MIKRO-Tip 2.0-Fr, Millar Instruments, Houston, TX) was inserted into the left ventricle to quantify maximum elastance as an index of contractility. Myocardial tissue Po2 was measured using a fiberoptic oxygen probe.


RESULTS
Maximum elastance decreased after lipopolysaccharide relative to control (47%, from 5.9 +/- 0.8 to 3.1 +/- 0.4 mm Hg/microL, p < .05). Albumin resuscitation prevented the lipopolysaccharide-induced decrease in maximum elastance (7.0 +/- 1.2 mm Hg/microL, p < .05 vs. lipopolysaccharide). Myocardial tissue Po2 was reduced in endotoxemia compared with control (53%, from 10.1 +/- 0.9 to 4.7 +/- 0.6 mm Hg, p < .05), and albumin resuscitation improved the lipopolysaccharide-induced tissue hypoxia toward the control value (9.0 +/- 1.4 mm Hg, p < .05).


CONCLUSIONS
Albumin resuscitation improved decreased ventricular contractility and myocardial oxygenation in endotoxemic rats. This result suggests that albumin resuscitation may improve ventricular dysfunction by improving myocardial hypoxia.
Tokunaga
Chiho
C
Critical Care Research Laboratories, University of British Columbia, Vancouver, Canada.
Bateman
Ryon M
RM
Boyd
John
J
Wang
Yingjin
Y
Russell
James A
JA
Walley
Keith R
KR
D000418:Albumins / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D004195:Disease Models, Animal; D019446:Endotoxemia / Q000628:therapy*; D004731:Endotoxins; D004926:Escherichia coli; D005440:Fluid Therapy / Q000379:methods*; D000860:Hypoxia / Q000503:physiopathology; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D008070:Lipopolysaccharides; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D016276:Ventricular Function / Q000187:drug effects
D000418:Albumins; D004731:Endotoxins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008070:Lipopolysaccharides; D012333:RNA, Messenger; C044101:endotoxin, Escherichia coli; D010100:Oxygen