Effect of intra-abdominal pressure on hepatic microcirculation: implications of the endothelin-1 receptor.
OBJECTIVE
To investigate the effect of endothelin receptor A (ET(A)) and endothelin receptor B (ET(B)) blockade on liver microcirculation and oxygenation during intra-abdominal pressure (IAP) increase.


METHODS
Fifteen anesthetized pigs were randomized to receive either nonselective endothelin-1 (ET-1) blocker tezosentan (TG, n = 7) or saline (CG, n = 8). Helium was insufflated to increase IAP from 0 to 25 mmHg. Stroke volume variability was maintained ≤ 12% with colloid infusion. Total liver blood flow (TLBF), hepatic microcirculatory blood flow (MBF), hepatic tissue oxygenation (HpO(2)), hyaluronic acid and plasma disappearance rate (PDR) of indocyanine green (ICG) were recorded.


RESULTS
TLBF remained mostly unaltered in both groups at low IAP and decreased only in CG at the IAP of 25 mmHg. As IAP increased, a significant decline in MBF was observed without correlation with cardiac output or TLBF. In CG, HpO(2) decreased as early as IAP of 10 mmHg to high levels of pressure. However, in TG the decrease was significant only at the IAP of 25 mmHg. PDR of ICG decreased in both groups at IAP of 25 mmHg (P = 0.046 and P = 0.009 in TG and CG, respectively). These changes correlated with MBF (r = 0.793).


CONCLUSIONS
Blocking ET(A) and ET(B) receptors partially protects sinusoidal circulation and tissue oxygenation against stress induced by high IAP.
Department of Anesthesiology, Hospital Clinic, Barcelona, Spain. getayo@gmail.com
Gerard
G
Sánchez-Etayo
Xavier
X
Borrat
Bibiana
B
Escobar
Amelia
A
Hessheimer
Gonzalo
G
Rodriguez-Laiz
Pilar
P
Taura
D000005:Abdomen / Q000502:physiology*; D000818:Animals; D005260:Female; D006439:Hemodynamics; D006820:Hyaluronic Acid / Q000097:blood; D008099:Liver / Q000378:metabolism; D008102:Liver Circulation; D008833:Microcirculation; D010100:Oxygen / Q000378:metabolism; D011028:Pneumoperitoneum, Artificial; D011312:Pressure; D011897:Random Allocation; D044022:Receptor, Endothelin A / Q000502:physiology*; D013552:Swine
D044022:Receptor, Endothelin A; D006820:Hyaluronic Acid; D010100:Oxygen