Prevalence and Clinical Impact of a Subclinical Intrapulmonary Right to Left Shunt Diagnosed by Contrast Echocardiography in Patients with End Stage Hepatic Disease

Background and Objectives:The clinical impact of an intrapulmonary right to left shunt, without hypoxia (subclinical IPS), has not been sufficiently evaluated. We investigated the prevalence and clinical impact of a subclinical IPS in patients with end stage hepatic disease. Subjects and Methods:Contrast echocardiography, with hand-agitated saline, was performed in 72 consecutive candidates for a liver transplantation between April 2001 and November 2001. A positive contrast echocardiography indicated an intrapulmonary right to left shunt, and was defined as the delayed appearance of microbubbles in the left side of the heart (3 to 6 beats after the initial appearance in the contrast in the right side of the heart). We compared the clinical events of the patients both with and without a shunt, i.e. death, spontaneous bacterial peritonitis, sepsis, hepatic encephalopathy or variceal bleeding. Results:A subclinical IPS was detected in 19 of the 72 candidates for a liver transplantation (26.3%). All these candidates were Child class C liver cirrhosis. There were no differences in the baseline characteristics between the patients and those without a shunt in the Child class C (n=57). The mean PaO2 value of the patients with at least a 3+ left ventricular opacification (3 to 4+, n=6) was significantly lower than those with a 1+ to 2+ left ventricular opacification (n=13) (76±10 mmHg vs. 103±13 mmHg, p< 0.05). The mortality was not significantly difference between the patients with (5%, 1/19) or without (21%, 8/38, p=0.24) a shunt. Also, there were no significant differences in the clinical events during the mean follow-up period of 7±3 months (68.4% vs. 83.5% p=0.12). Conclusion:Subclinical IPS's are not uncommon in patients with end stage hepatic disease. The extent of shunting correlates with the level of arterial 논문접수일:2002년 10월 21일 수정논문접수일:2002년 11월 5일 심사완료일:2002년 11월 28일 교신저자:송재관, 138-736 서울 송파구 풍납동 388-1 울산대학교 의과대학 서울아산병원 내과학교실 전화:(02) 3010-3150·전송:(02) 486-5918·E-Mail:jksong@amc.seoul.kr