Relationship of 24-hour ambulatory blood pressure and heart rate with markers of hepatic function in cirrhotic patients

Implication of Hypotension in the Pathogenesis of Cognitive Impairment and Brain Injury in Chronic Liver Disease

The incidence of chronic liver disease is on the rise. One of the primary causes of hospital admissions for patients with cirrhosis is hepatic encephalopathy (HE), a debilitating neurological complication. HE is defined as a reversible syndrome, yet there is growing evidence stating that, under certain conditions, HE is associated with permanent neuronal injury and irreversibility. The pathophysiology of HE primarily implicates a strong role for hyperammonemia, but it is believed other pathogenic factors are involved. The fibrotic scarring of the liver during the progression of chronic liver disease (cirrhosis) consequently leads to increased hepatic resistance and circulatory anomalies characterized by portal hypertension, hyperdynamic circulatory state and systemic hypotension. The possible repercussions of these circulatory anomalies on brain perfusion, including impaired cerebral blood flow (CBF) autoregulation, could be implicated in the development of HE and/or permanent brain injury. Furthermore, hypotensive insults incurring during gastrointestinal bleed, infection, or liver transplantation may also trigger or exacerbate brain dysfunction and cell damage. This review will focus on the role of hypotension in the onset of HE as well as in the occurrence of neuronal cell loss in cirrhosis.

Autonomic Nervous System Profiling In Response to Liver Transplantation: Prognostic Evaluation and Preliminary Study

BACKGROUND

Liver cirrhosis leads to autonomic dysfunction (AD). We present a pilot study and review of published literature to investigate the long-term changes in the Autonomic Nervous System (ANS) of patients who underwent liver transplant. We propose Autonomic Function Tests (AFT) can be used as a predictor of liver transplant outcome.

METHODS

Twenty-eight patients (19 men and 9 women; mean age 45 years) with cirrhosis due to different etiologies underwent a noninvasive ANS evaluation test, pre- and post-liver transplant at 3 to 6 months, 8 to 12 months, and 14 to 24 months. Data were compared with 45 age-matched controls (14 men and 31 women). We investigated changes in the following 3 adrenergic measures: percentage of cutaneous vasoconstriction in the hand and foot in response to cold stress test and cutaneous blood flow adjustment ratio; and 3 cardiovagal measures: change in heart rate in relation to deep respiration, forced respiration represented as Valsalva Ratio, and head-up tilting (30/15 ratio).

RESULTS

A total of 23 of 28 patients (82%) had impairment in AFT before transplant, 16 of 28 (57%) in the sympathetic adrenergic measures, and 15 of 28 (54%) in the parasympathetic cardiovagal measures. There was a gradual improvement in ANS function posttransplant, with a significant improvement in the cardiovagal measure of Valsalva Ratio (P < .05 from baseline). These data suggest some temporary decline in ANS functions within the first 6 months posttransplant.

CONCLUSIONS

To optimize outcomes in liver transplant patients with autonomic dysfunction, autonomic testing perhaps combined with frailty testing can be used as objective measures of mortality in the pre-liver transplant stage.

The role of autonomic dysfunction in cirrhotic patients before and after liver transplantation. Review of the literature

In patients affected by hepatic cirrhosis, autonomic dysfunction is a common finding; usually it is asymptomatic but it may correlate with increased mortality and morbidity before, during and after liver transplant, due to hemodynamic instability in the course of stressful events like sepsis, gastrointestinal bleeding and reperfusion after transplantation surgery. Hyperdynamic circulation and hepatic dysfunction seem to play a role in the pathogenesis of autonomic dysfunction, even if pathophysiological mechanisms are not completely known. We present a revision of previous literature about prevalence, pathophysiological mechanisms, clinical features, and mortality and morbidity of autonomic dysfunction secondary to hepatic cirrhosis.