Liver transplantation : official publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society
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Comparative Study
Effects of hyperbaric oxygen exposure on experimental hepatic ischemia reperfusion injury: relationship between its timing and neutrophil sequestration.
Recent studies have shown that hyperbaric oxygen therapy (HBOT) reduces neutrophil endothelial adherence in venules and also blocks the progressive arteriolar vasoconstriction associated with ischemia-reperfusion (I-R) injury in the extremities and the brain. In order to elucidate the effects of HBOT after I-R in digestive organs, particularly in the liver, we evaluated the following: 1) the relationship between timing of HBOT and tissue damage; and 2) HBOT's effects on neutrophil sequestration. Using a hepatic I-R (45 minute) model in male rats, survival rate, liver tissue damage, and neutrophil accumulation within the sinusoids in the HBOT-treated group (Group H) were compared to those in the nontreated group (Group C). ⋯ These results indicate that HBOT performed within 3 hours of I-R alleviates hepatic dysfunction and improves the survival rate after I-R. Herein, we propose 1 possible mechanism for these beneficial effects: early HBOT given before neutrophil-mediated injury phase may suppress the accumulation of neutrophils after I-R. In conclusion, we believe that the present study should lead to an improved understanding of HBOT's potential role in hepatic surgery.
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Multicenter Study Comparative Study
Complications and use of intracranial pressure monitoring in patients with acute liver failure and severe encephalopathy.
Monitoring of intracranial pressure (ICP) in acute liver failure (ALF) is controversial as a result of the reported complication risk (approximately 20%) and limited therapeutic options for intracranial hypertension. Using prospectively collected information from 332 patients with ALF and severe encephalopathy, we evaluated a recent experience with ICP monitoring in the 24 centers constituting the U. S. ⋯ In conclusion, the risk of intracranial hemorrhage following ICP monitoring may have decreased in the last decade, but major complications are still present. In the absence of ICP monitoring, however, patients listed for LT appear to be treated less aggressively for intracranial hypertension. In view of the high 30-day survival rate after LT, future studies of the impact of intracranial hypertension should also focus on long-term neurological recovery from ALF.
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Comparative Study
Cerebral hemodynamic and metabolic profiles in fulminant hepatic failure: relationship to outcome.
The purpose of this retrospective study was to examine the potential role of cerebral hemodynamic and metabolic factors in the outcome of patients with fulminant hepatic failure (FHF). Based on the literature, a hypothetical model was proposed in which physiologic changes progress sequentially in five phases, as defined by intracranial pressure (ICP) and cerebral blood flow (CBF) measurements. Seventy-six cerebral physiologic profiles were obtained in 26 patients (2 to 5 studies each) within 6 days of FHF diagnosis. ⋯ All 6 revealed malignant intracranial hypertension, preceded by hyperemia. In conclusion, the above findings are consistent with the hypothetical model proposed. Prospective longitudinal studies are recommended to determine the precise evolution of the pathophysiologic changes.
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It is not known whether patients with pulmonary arterial hypertension associated with portal hypertension (portopulmonary hypertension (PPHTN) have different disease characteristics from those of patients with other forms of pulmonary arterial hypertension. We performed a retrospective cohort study of patients with PPHTN and patients with pulmonary arterial hypertension that was idiopathic, familial, or associated with anorexigen use (IPAH) to determine whether hemodynamics or survival were different between these groups. We included consecutive patients who underwent initial pulmonary artery catheterization and vasodilator testing at our center between January 1997 and May 2001 and who were followed until January 2004. ⋯ These findings were not affected by adjustment for differences in laboratory values, hemodynamics, or therapy. In conclusion, patients with PPHTN have a higher risk of death than that of patients with IPAH, despite having a higher cardiac index and lower pulmonary vascular resistance. Future studies of the specific mechanisms of and therapy for pulmonary arterial hypertension should focus on the distinctions between the different forms of this disease.