GASTROENTEROLOGY 1993;104:222-227 Hemodynamic Effects of Acute Changes in Intra-abdominal Pressure in Patients With Cirrhosis zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA ANGELO LUCA, ISABEL CIRERA, JUAN CARLOS GARCIA-PAGAN, FAUST0 FEU, PILAR PIZCUETA, JAIME BOSCH, and JUAN ROD& zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clinic i Provincial, University of Barcelona, Barcelona Spain Background: Changes in intra-abdominal pressure (IAP) have significant circulatory effects. However, whether this may influence the gastroesophageal col- lateral blood flow in patients with cirrhosis has not been studied. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Methods: In 14 portal hypertensive cir- rhotics, serial hemodynamic measurements were ob- tained in baseline conditions 30 minutes after the me- chanical increase of IAP by 10 mm Hg and 30 minutes after returning IAP to baseline levels. Results: Increas- ing IAP caused similar increases in free and wedged hepatic venous pressures (+10.3 mm Hg and zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA +l zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 1.0 mm Hg, respectively; P < 0.005), without changing the hepatic venous pressure gradient (HVPG). However, there were significant decreases in cardiac output (-18%; P < 0.005) and hepatic blood flow (-20%; P < 0.05), whereas azygos blood flow, an index of gastro- esophageal collateral blood flow, increased markedly (+23%; P < 0.005). The opposite occurred after re- leasing the high IAP. Conclusion: In portal hypertensive cirrhotics, acute changes in IAP did not change HVPG but markedly modified splanchnic and systemic hemo- dynamics. Brief elevations of IAP may have dele- tereous effects, as shown by the increase in azygos blood flow and the decrease in cardiac output and he- patic blood flow, whereas reduction of a high IAP causes the opposite changes and may be beneficial. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA H zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA epatic vein catheterization, with measurements of wedged and free hepatic venous pressures (WHVP and FHVP, respectively), is widely used to assess portal pressure in patients with sinusoidal portal hypertension. The results of these studies are usually expressed as the hepatic venous pressure gradient (HVPG), the difference between WHVP and FHVP. Several studies have shown that changes in intra-ab- dominal pressure (IAP) modify both WHVP and FHVP but do not change the HVPG.le3 Therefore, a lack of change in HVPG is usually taken as evidence of an absence of changes in hepatic hemodynamics. Iw a- tsuki et al. did not find changes in HVPG and hepatic blood flow after acute changes in IAP caused by pneu- moperitoneum and paracentesis in patients with cir- rhosis.3 However, several studies have shown marked changes in cardiac index after paracentesis.“ ” Further- more, experimental studies have shown that increasing the IAP reduces the splanchnic blood flow in normal and portal hypertensive animals.1°-15 On the other hand, it has been suggested that modifications in IAP, even without changes in HVPG, may influence blood flow through gastroesophageal varices by modifying the pressure gradient between the portal vein and the thoracic veins. 3,16’9 However, this has never been in- vestigated. The present study addresses these issues by studying the effects of acute changes in IAP on hepatic hemody- namics, azygos blood flow (an index of blood flow through gastroesophageal collaterals and esophageal varices), and systemic circulation in a series of patients with cirrhosis and portal hypertension. Materials and Methods Design of the Study The study was designed to assess the effects of acute changes in IAP on gastroesophageal collateral blood flow and on the hepatic and systemic hemodynamics in portal hypertensive cirrhotics. Hemodynamic measurements and blood samples for catecholamines were obtained in baseline conditions, 30 minutes after increasing IAP by 10 mm Hg, and again 30 minutes after returning IAP to baseline levels. IAP was increased by placing a sand bag over the abdomen then tightening it to increase IAP by 10 mm Hg. Patients The study was performed in 14 cirrhotic patients referred to the Hepatic Hemodynamics Laboratory at the Liver Unit for the evaluation of portal hypertension. Eleven patients were male and three were female, with a mean age of 54 [f8 (SD)] years. The etiology of cirrhosis was alco- Abbreviations used in this paper: AzVP, azygos vein pressure; CO, cardiac output; FHVP, free hepatic venous pressure; HVPG, hepatic venous pressure gradient; IAP, intra-arterial pressure: MAP, mean arterial pressure; RAP, right atrial pressure; SVR, systemic vascular resistance; WHVP, wedged hepatic venous pressure. 0 1993 by the American Gastroenterological Association 0016~5065/93/$3.00