Early radionuclide detection of intrapulmonary shunts in children with liver disease

In order to detect and quantify intrapulmonary shunts in children with liver disease, a radionuclide method was developed and evaluated in such a population. Methods: We studied 135 children in whom the severity of liver disease, in most cases, justified consideration of liver transplantation. Patients were separated into two groups according to their resting PaO₂ values under room air: 109 children were normoxic and 26 were hypoxic. A radionuclide scan was performed immediately after intravenous injection of human albumin macroaggregates. Activity of the lungs (L) and brain (B) was counted. A shunt index (SI) was calculated as SI = 100 · B/L. We compared this index with blood gases and clinical follow-up. Results: In the normoxic group, SI was 0.43 ± 0.30 (mean ± s.d.); none of the 102 children with SI < 1 developed hypoxemia during their follow-up. Two of the six children with SI > 1 developed subsequent hypoxemia. In the hypoxic group, the nine children with SI < 1 did not aggravate their hypoxemia during follow-up. The 17 hypoxic children with SI > 1 later developed severe hypoxemia. Conclusions: Scintigraphy with intravenous human albumin macroaggregates is more accurate than measuring arterial blood gases to detect IPS in children with cirrhosis.