Gundling F, Zelihic E, Seidl H, Haller B, Umgelter A, Schepp W, Dodt C

Language: English
References: 15
Page: 108-114
PDF size: 143.29 Kb.

ABSTRACT

Introduction. Blood ammonia-measurements are often performed in the emergency departments to diagnose or rule out hepatic encephalopathy (HE). However, the utility and correct interpretation of ammonia levels is a matter of discussion. At this end the present prospective study evaluated whether blood ammonia levels coincide with HE which was also established by the West Haven criteria and the critical flicker frequency, respectively. Material and methods. In 59 patients with known cirrhosis ammonia-levels were determined and patient were additionally categorized by the West-Haven criteria and were also evaluated psychophysiologically using the critical flicker frequency, CFF for the presence of HE. Results. When false positive and false negative results were collapsed the determination of blood ammonia levels alone resulted in 40.7% in a misdiagnoses of HE compared to the West-Haven criteria (24/59 when using West-Haven criteria, 95% confidence interval [CI], 28.1% to 54.3%) and 49.2% when compared with the results of the CFF (29/59, when using CFF, 95% CI, 35.9% to 62.5%). Discussion. Ammonia blood levels do not reliably detect HE and the determination of blood ammonia can not be regarded a useful screening test for HE. Its use as sole indicator for a HE in the Emergency Department may frequently result in frequent misinterpretations.

REFERENCES

1. Bajaj JS. The modern management of hepatic encephalopathy. Aliment Pharmacol Ther 2009; 31: 537-47.

2. Ferenci P, Lockwood A, Mullen K, Tarter R, Weissenborn K, Blei AT. Hepatic encephalopathy-definition, nomenclature, diagnosis, and quantification: final report of the working party at the 11th World Congress of Gastroenterology, Vienna, 1998. Hepatology 2002; 35: 716-21.

3. Kircheis G, Wettstein M, Timmermann L, Schnitzler A, Häussinger D. Critical flicker frequency for quantification of low-grade hepatic encephalopathy. Hepatology 2002; 35: 357-66.

4. McPhail MJ, Bajaj RS, Thomas HC, Taylor-Robinson SD. Pathogenesis and diagnosis of hepatic encephalopathy. Expert Rev Gastroenterol Hepatol 2010; 4: 365-78.

5. Romero-Gómez M, Córdoba J, Jover R, del Olmo JA, Ramírez M, Rey R, de Madaria E, et al. Value of the critical flicker frequency in patients with minimal hepatic encephalopathy. Hepatology 2007; 45: 879-85.

6. Sharma P, Sharma BC, Puri V, Sarin SK. Critical flicker frequency: Diagnostic tool for minimal hepatic encephalopathy. J Hepatol 2007; 47: 67-73.

7. Butterworth RF, Giguère JF, Michaud J, Lavoie J, Layrargues GP. Ammonia: a key factor in the pathogenesis of hepatic encephalopathy. Neurochem Pathol 1987; 6: 1-12.

8. Ong JP, Aggarwal A, Krieger D, Easley KA, Karafa MT, Van Lente F, Arroliga AC, Mullen KD. Correlation between ammonia levels and the severity of hepatic encephalopathy. Am J Med 2003; 114: 188-93.

9. Nicolao F, Efrati C, Masini A, Merli M, Attili AF, Riggio O. Role of determination of partial pressure of ammonia in cirrhotic patients with and without hepatic encephalopathy. J Hepatol 2003; 38: 441-6.

10. Arora S, Martin CL, Herbert M. Myth: Interpretation of a single ammonia level in patients with chronic liver disease can confirm or rule out hepatic encephalopathy. Can J Emerg Med 2006; 8: 433-5.

11. Dhiman RK, Saraswat VA, Sharma BK, Sarin SK, Chawla YK, Butterworth R, Duseja A, et al. Minimal hepatic encephalopathy: Consensus statement of a working party of the Indian National Association for Study of the Liver. J Gastroenterol Hepatol 2010; 25: 1029-41.

12. Gundling F, Seidl H, Schmidt T, Schepp W. Blood ammonia level in liver cirrhosis: a conditio sine qua non to confirm hepatic encephalopathy? Eur J Gastroenterol Hepatol 2008; 20: 246-7.

13. Felipo V, Urios A, Montesinos E, Molina I, Garcia-Torres ML, Civera M, Olmo JA, et al. Contribution of hyperammonemia and inflammatory factors to cognitive impairment in minimal hepatic encephalopathy. M tab Brain Dis 2012; .

14. Shawcross DL, Sharifi Y, Canavan JB, Yeoman AD, Abeles RD, Taylor NJ, Auzinger G, et al. Infection and systemic inflammation, not ammonia, are associated with Grade 3/4 hepatic encephalopathy, but not mortality in cirrhosis. J Hepatol 2011; 54: 640-9.

15. Shawcross DL, Shabbir SS, Taylor NJ, Hughes RD. Ammonia and the neutrophil in the pathogenesis of hepatic encephalopathy in cirrhosis. Hepatology 2010; 51: 1062-9.