Effects of Abdominal Hot Compresses on Indocyanine Green Elimination in Healthy Subjects

We investigated, whether abdominal hot compresses effect hepatic blood flow. Our hypothesis was, that the hot compresses might either by local vasomotor-reflex or by decreasing the tone of the sympathetic nerve system increase hepatic blood flow.

Abdominal hot compresses are traditionally used by patients with liver diseases as self help. This study investigated the effect of abdominal hot compresses on hepatic blood flow measured by elimination of indocyanine green (ICG), a non-toxic green dye. It was presumed, that abdominal hot compresses increase hepatic blood flow either by local vasomotor-reflex or by decreasing the tone of the sympathetic nerve system.

In healthy volunteers ICG elimination was measured with and without hot compress at two investigations in a weekly interval. At each investigation ICG was injected as bolus after a rest period of 10 minutes. After the injection blood was taken in regular intervals for analysis of ICG concentration over a period of 40 minutes and half life was calculated.

The time interval between the investigations was 8 days, the sequence was randomly assigned.

Inclusion Criteria:

• healthy volunteers

Exclusion Criteria:

• iodine allergy
• any acute or chronic disease [with exception of pollinosis because it is common]
• elevated levels of alanine amino transferase [ALT], aspartate amino transferase [AST], gamma glutamyltransferase [GGT] or bilirubin
• heat urticaria
• pregnancy
• alcohol intake >30 g/d
• any medication except contraceptives
• body mass index (BMI) >30 kg/m2