Clinical

High blood ammonia in cirrhosis points to esophageal varices

Last Updated: 2009-03-25 15:02:00 -0400 (Reuters Health)

NEW YORK (Reuters Health) - A high blood ammonia concentration in cirrhotic patients provides a clue to the presence of esophageal varices, clinicians from Italy have found.

In comments to Reuters Health, Dr. Giovanni Tarantino from Federico II University Medical School of Naples noted that there is a "need to verify the presence of esophageal varices in patients suffering from liver cirrhosis at the earliest possible time in the progression of disease by means of upper GI endoscopy in order to elude a hemorrhage."

The current findings, he added, raise the possibility of using "blood ammonia levels to diagnose the presence of this ongoing process."

Dr. Tarantino and colleagues investigated the diagnostic utility of venous ammonia levels, spleen size, and platelet count as noninvasive markers of portosystemic shunt presence, particularly esophageal varices, in 153 consecutive patients with hepatic cirrhosis of various etiologies.

All patients underwent endoscopy and ultrasonography screening for the presence of portosystemic collateral veins, mostly esophageal varices, "which have the greatest clinical impact and the most severe complications," the investigators note in a report posted online March 17 in the journal BMC Gastroenterology.

Esophageal varices were present in 70 patients, or 45% of the group, and, according to the investigators, there was a "good association" between abnormally elevated blood ammonia levels and the presence and grade of esophageal varices.

Specifically, the median level of blood ammonia was 45 mcM/L in 64 patients in Child-Pugh class A, 66 mcM/L in the 66 class B patients, and 108 mcM/L in the 23 Child-Pugh class C patients (p < 0.001).

Ammonia levels also predicted hepatic decompensation and the presence of ascites.

"Health care costs are skyrocketing and physicians should favor diagnostic procedures technically sound, but the least likely expensive," Dr. Tarantino noted. "Admittedly, our research does not limit the indication of endoscopy but suggests a more profitable use of this tool."

Prolonged high blood ammonia levels "should induce hospitalists to advise their patients to undergo endoscopy as soon as possible," Dr. Tarantino suggested. Conversely, low ammonia levels "could temporarily avoid performing this expensive and invasive procedure."

"Blood ammonia determinations," he added, "should be performed paying particularly attention to blood sampling."

BMC Gastroenterology 2009;9.