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Blood ammonia levels in liver cirrhosis: a clue for the presence of portosystemic collateral veins.

Tarantino G, Citro V, Esposito P, Giaquinto S, de Leone A, Milan G, Tripodi FS, Cirillo M, Lobello R - BMC Gastroenterol (2009)

Bottom Line: The resulting shunting is responsible for the development of portosystemic encephalopathy.Although ammonia plays a certain role in determining portosystemic encephalopathy, the venous ammonia level has not been found to correlate with the presence or severity of this entity.Realizing the need for non-invasive markers mirroring the presence of esophageal varices in order to reduce the number of endoscopy screening, we came back to determine whether there was a correlation between blood ammonia concentrations and the detection of portosystemic collateral veins, also evaluating splenomegaly, hypersplenism (thrombocytopenia) and the severity of liver cirrhosis.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Clinical and Experimental Medicine, Hepatology in Internal Medicine Section, Federico II University Medical School of Naples, Naples, Italy. tarantin@unina.it

ABSTRACT

Background: Portal hypertension leads to the formation of portosystemic collateral veins in liver cirrhosis. The resulting shunting is responsible for the development of portosystemic encephalopathy. Although ammonia plays a certain role in determining portosystemic encephalopathy, the venous ammonia level has not been found to correlate with the presence or severity of this entity. So, it has become partially obsolete. Realizing the need for non-invasive markers mirroring the presence of esophageal varices in order to reduce the number of endoscopy screening, we came back to determine whether there was a correlation between blood ammonia concentrations and the detection of portosystemic collateral veins, also evaluating splenomegaly, hypersplenism (thrombocytopenia) and the severity of liver cirrhosis.

Methods: One hundred and fifty three consecutive patients with hepatic cirrhosis of various etiologies were recruited to participate in endoscopic and ultrasonography screening for the presence of portosystemic collaterals mostly esophageal varices, but also portal hypertensive gastropathy and large spontaneous shunts.

Results: Based on Child-Pugh classification, the median level of blood ammonia was 45 mcM/L in 64 patients belonging to class A, 66 mcM/L in 66 patients of class B and 108 mcM/L in 23 patients of class C respectively (p < 0.001).The grade of esophageal varices was concordant with venous ammonia levels (rho 0.43, p < 0.001). The best area under the curve was given by ammonia concentrations, i, e., 0.78, when comparing areas of ammonia levels, platelet count and spleen longitudinal diameter at ultrasonography. Ammonia levels predicted hepatic decompensation and ascites presence (Odds Ratio 1.018, p < 0.001).

Conclusion: Identifying cirrhotic patients with high blood ammonia concentrations could be clinically useful, as high levels would lead to suspicion of being in presence of collaterals, in clinical practice of esophageal varices, and pinpoint those patients requiring closer follow-up and endoscopic screening.

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Serial measurements. Clustered multiple comparison graph showing a good repeatability of blood ammonia concentration over time; median of the maximum difference versus first value percentage = -22.5, 95% C.I. -29.74 to 12.4; median of the AUC, (baseline = first value) = -577.5, C.I. = -1027.76 to 229.84; AUC, Area Under the Curve.
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Figure 3: Serial measurements. Clustered multiple comparison graph showing a good repeatability of blood ammonia concentration over time; median of the maximum difference versus first value percentage = -22.5, 95% C.I. -29.74 to 12.4; median of the AUC, (baseline = first value) = -577.5, C.I. = -1027.76 to 229.84; AUC, Area Under the Curve.

Mentions: To asses if blood ammonia concentrations of cirrhotic patients were constant on time, eight of them were studied at a two week-distance for one month and half. The results showed a low difference of the remaining values versus the first one and a near flat AUC, as evidenced in Figure 3.


Blood ammonia levels in liver cirrhosis: a clue for the presence of portosystemic collateral veins.

Tarantino G, Citro V, Esposito P, Giaquinto S, de Leone A, Milan G, Tripodi FS, Cirillo M, Lobello R - BMC Gastroenterol (2009)

Serial measurements. Clustered multiple comparison graph showing a good repeatability of blood ammonia concentration over time; median of the maximum difference versus first value percentage = -22.5, 95% C.I. -29.74 to 12.4; median of the AUC, (baseline = first value) = -577.5, C.I. = -1027.76 to 229.84; AUC, Area Under the Curve.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2662872&req=5

Figure 3: Serial measurements. Clustered multiple comparison graph showing a good repeatability of blood ammonia concentration over time; median of the maximum difference versus first value percentage = -22.5, 95% C.I. -29.74 to 12.4; median of the AUC, (baseline = first value) = -577.5, C.I. = -1027.76 to 229.84; AUC, Area Under the Curve.
Mentions: To asses if blood ammonia concentrations of cirrhotic patients were constant on time, eight of them were studied at a two week-distance for one month and half. The results showed a low difference of the remaining values versus the first one and a near flat AUC, as evidenced in Figure 3.

Bottom Line: The resulting shunting is responsible for the development of portosystemic encephalopathy.Although ammonia plays a certain role in determining portosystemic encephalopathy, the venous ammonia level has not been found to correlate with the presence or severity of this entity.Realizing the need for non-invasive markers mirroring the presence of esophageal varices in order to reduce the number of endoscopy screening, we came back to determine whether there was a correlation between blood ammonia concentrations and the detection of portosystemic collateral veins, also evaluating splenomegaly, hypersplenism (thrombocytopenia) and the severity of liver cirrhosis.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Clinical and Experimental Medicine, Hepatology in Internal Medicine Section, Federico II University Medical School of Naples, Naples, Italy. tarantin@unina.it

ABSTRACT

Background: Portal hypertension leads to the formation of portosystemic collateral veins in liver cirrhosis. The resulting shunting is responsible for the development of portosystemic encephalopathy. Although ammonia plays a certain role in determining portosystemic encephalopathy, the venous ammonia level has not been found to correlate with the presence or severity of this entity. So, it has become partially obsolete. Realizing the need for non-invasive markers mirroring the presence of esophageal varices in order to reduce the number of endoscopy screening, we came back to determine whether there was a correlation between blood ammonia concentrations and the detection of portosystemic collateral veins, also evaluating splenomegaly, hypersplenism (thrombocytopenia) and the severity of liver cirrhosis.

Methods: One hundred and fifty three consecutive patients with hepatic cirrhosis of various etiologies were recruited to participate in endoscopic and ultrasonography screening for the presence of portosystemic collaterals mostly esophageal varices, but also portal hypertensive gastropathy and large spontaneous shunts.

Results: Based on Child-Pugh classification, the median level of blood ammonia was 45 mcM/L in 64 patients belonging to class A, 66 mcM/L in 66 patients of class B and 108 mcM/L in 23 patients of class C respectively (p < 0.001).The grade of esophageal varices was concordant with venous ammonia levels (rho 0.43, p < 0.001). The best area under the curve was given by ammonia concentrations, i, e., 0.78, when comparing areas of ammonia levels, platelet count and spleen longitudinal diameter at ultrasonography. Ammonia levels predicted hepatic decompensation and ascites presence (Odds Ratio 1.018, p < 0.001).

Conclusion: Identifying cirrhotic patients with high blood ammonia concentrations could be clinically useful, as high levels would lead to suspicion of being in presence of collaterals, in clinical practice of esophageal varices, and pinpoint those patients requiring closer follow-up and endoscopic screening.

Show MeSH
Related in: MedlinePlus