Blood Ammonia Levels (blood + ammonia_level)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Cerebral oedema in minimal hepatic encephalopathy due to extrahepatic portal venous obstruction

LIVER INTERNATIONAL, Issue 8 2010
Amit Goel
Abstract Background: Minimal hepatic encephalopathy (MHE) has recently been reported in patients with extrahepatic portal venous obstruction (EHPVO). Aims: To evaluate brain changes by magnetic resonance studies in EHPVO patients. Methods: Blood ammonia level, critical flicker frequency (CFF), brain metabolites on 1H-magnetic resonance (MR) spectroscopy and brain water content on diffusion tensor imaging and magnetization transfer ratio (MTR) were studied in 31 EHPVO patients with and without MHE, as determined by neuropsychological tests. CFF and magnetic resonance imaging studies were also performed in 23 controls. Results: Fourteen patients (14/31, 45%) had MHE. Blood ammonia level was elevated in all, being significantly higher in the MHE than no MHE group. CFF was abnormal in 13% (4/31) with EHPVO and in 21% (3/14) with MHE. On 1H-MR spectroscopy, increased Glx/Cr, decreased mIns/Cr, and no change in Cho/Cr were noted in patients with MHE compared with controls. Significantly increased mean diffusivity (MD) and decreased (MTR) were observed in the MHE group, suggesting presence of interstitial cerebral oedema (ICE). MD correlated positively with blood ammonia level (r=0.65, P=0.003) and Glx (r=0.60, P=0.003). Discussion: MHE was detected in 45% of patients with EHPVO while CFF was abnormal in only 13%. ICE was present in 7/10 brain regions examined, particularly in those with MHE. Hyperammonaemia elevated cerebral Glx levels correlated well with ICE. Conclusions: MHE was common in EHPVO; CFF could identify it only in a minority. ICE was present in EHPVO, particularly in those with MHE. It correlated with blood ammonia and Glx/Cr levels. Hyperammonaemia seems to contribute to ICE in EHPVO. [source]

GASTRIC FUNDIC VARICES: HEMODYNAMICS AND NON-SURGICAL TREATMENT

DIGESTIVE ENDOSCOPY, Issue 3 2005
Seishu Hayashi
The hemodynamics and non-surgical treatment of gastric fundic varices (FV) are reviewed. FV are more frequently supplied by the short and posterior gastric veins than esophageal varices (EV), and are formed mostly by large spontaneous shunts in which the gastric or splenic vein is continuous with the left renal vein via the inferior phrenic veins and the suprarenal vein (so-called gastric-renal shunt). Concomitant collaterals such as EV, para-esophageal vein, and para-umbilical vein were also observed in nearly 60% of FV. Endoscopic injection sclerotherapy (EIS) with Histoacryl is thought to be the most approved treatment for hemorrhage from FV, but repeated treatment for residual FV and care for ensuing hepatic failure are required. Balloon-occluded retrograde transvenous obliteration (B-RTO) is a notable interventional radiological procedure specially developed for the elective or prophylactic treatment of FV. If the procedure is technically successful, long-term eradication of treated FV is found in most patients without recurrence. B-RTO includes another significance, obliteration of the unified portal-systemic shunt. Follow-up abdominal CT scan revealed a high incidence of long-term obliteration of the gastric-renal shunt after B-RTO. Benefits such as elevation of serum albumin, improvement in 15-min retention rate of indocyanine green, decrease in blood ammonia levels, and improvement of encephalopathy are sometimes observed. [source]

Topiramate Enhances the Risk of Valproate-associated Side Effects in Three Children

EPILEPSIA, Issue 4 2002
Elke Longin
Summary: ,Purpose: We present three children with severe therapy-refractory epilepsy who tolerated valproate (VPA) well in various combinations with other antiepileptic drugs (AEDs) but developed typical VPA side effects in combination with topiramate (TPM). Methods: The clinical symptoms began with apathy in all three children; two of them also had hypothermia. Furthermore all children had elevated blood ammonia levels, one child in combination with increased liver transaminases and one with thrombocytopenia. Results: All children recovered completely after discontinuation of VPA or TPM. Conclusions: TPM seems likely to enhance the risk of side effects usually attributed to VPA and not described in TPM monotherapy. Our case reports suggest that possible adverse effects of VPA should be given particular attention when VPA is combined with TPM. [source]