Functional deterioration of the liver by elevated inferior vena cava pressure: a proposed upper safety limit of pressure for maintaining liver viability in dogs.
OBJECTIVE
Abnormally elevated central venous pressure is considered to be an etiological factor in the onset of acute hepatic failure following modified Fontan operation. This paper hypothesises that an increase in inferior vena cava pressure (IVCP) after such an operation has adverse effects on hepatic energy status.


METHODS
Various degrees of venous hypertension were produced in 10 mongrel dogs by clamping the thoracic IVC with an active veno-venous shunt and varying its flow rate from 60-2.5 ml/min/kg. Arterial ketone body ratio (KBR), reflecting the hepatic mitochondrial redox state, was measured as an index of hepatic energy status.


RESULTS
The lower the flow rates of the shunt, the higher the pressures of IVC and portal vein, while systolic blood pressure was maintained above 100 mmHg. CO significantly decreased when the pump speed was less than 30 ml/min/kg. KBR showed a negative correlation to IVCP as well as a positive correlation to portal blood flow (p < 0.05).


CONCLUSIONS
From the simple regression line obtained between IVCP and KBR, it was determined that an upper safety limit of IVCP may lie at about 27 cmH2O (20.5 mmHg), and that a IVCP of 35 cmH2O (26.6 mmHg) seems to be the critical level for maintaining liver viability.
Higashiyama
H
H
Second Department of Surgery, Faculty of Medicine, Kyoto University, Japan.
Yamaguchi
M
M
Kumada
K
K
Sasaki
H
H
Yamaguchi
T
T
Ozawa
K
K
D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002496:Central Venous Pressure; D004195:Disease Models, Animal; D004285:Dogs; D004734:Energy Metabolism; D005260:Female; D006973:Hypertension / Q000209:etiology* / Q000378:metabolism*; D007657:Ketone Bodies / Q000097:blood*; D016014:Linear Models; D008102:Liver Circulation; D017114:Liver Failure, Acute / Q000209:etiology* / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism; D008991:Monitoring, Physiologic; D015999:Multivariate Analysis; D011167:Portacaval Shunt, Surgical; D011183:Postoperative Complications / Q000209:etiology* / Q000378:metabolism*; D014682:Vena Cava, Inferior / Q000601:surgery*
D007657:Ketone Bodies