Autoregulation Assessment During Liver Transplantation

NCT ID: NCT01425385

Last Updated: 2017-08-22

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 10 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2011-09-30
• Study Completion Date: 2012-09-30

Brief Summary

Patients with liver failure undergoing liver transplantation often have clinical or sub-clinical encephalopathy that may lead to increased intracranial pressure. The latter may lead to abnormal regulation of blood flow to the brain (cerebral autoregulation) complicating patient management during and after general anesthesia. The current methods for monitoring for elevated intracranial pressure are invasive and, thus, limited to severe encephalopathy. In this study the investigators will evaluate the potential utility of monitoring cerebral blood flow (CBF) autoregulation non-invasively using near infra-red spectroscopy in patients undergoing liver transplantation.

Detailed Description

Hepatic encephalopathy complicating chronic liver failure in patients undergoing liver transplantation increases the risk for adverse outcomes including mortality. Even mild hepatic encephalopathy may not be recognized clinically without specific testing but can be associated with impaired functional status and reduced quality of life before liver transplantation. The changes that can be seen in chronic liver failure, (cerebral edema and increased intracranial pressure) can adversely affect cerebral blood flow autoregulation that may predispose to brain injury during the multiple hemodynamic perturbations that occur during and after liver transplantation. Currently, invasive monitoring with an intracranial "bolt" is the only method to aggressively manage patients with elevated intracranial pressure from acute liver failure and hepatic encephalopathy. The placement of an intracranial pressure catheter in patient with liver failure is associated with a risk of brain hemorrhage due the presence of a coagulopathy. Further, the risk of this type of monitoring outweighs the benefits in the patients with milder or subclinical forms of hepatic encephalopathy. In this pilot study of 20 patients undergoing liver transplantation the investigators will evaluate the feasibility of non-invasive monitoring of CBF autoregulation and assess whether autoregulation is impaired in this group of patients. The investigators hypothesize that cerebral blood flow autoregulation is impaired in patients undergoing liver transplantation based on severity of liver disease. In this situation, improved patient monitoring would allow clinicians to maintain arterial blood pressure above an individual's lower limit of cerebral blood flow autoregulation that might prevent devastating brain injury during and after surgery. Cerebral blood flow autoregulation can be continuously monitored by evaluating the correlation coefficient between cerebral blood flow velocity measured with transcranial Doppler and arterial blood pressure. The investigators have developed a novel method of autoregulation monitoring using near infrared spectroscopy that allows continuous monitoring of autoregulation with the cerebral oximetry index and the hemoglobin volume index(, a moving linear correlation coefficient between cortical tissue oxygen saturation and hemoglobin level with arterial blood pressure, respectively. The latter approach is more practical and would allow widespread autoregulation monitoring in diverse clinical settings. A secondary hypothesis of this study is that near infrared spectroscopy-based monitoring of CBF autoregulation will provide an accurate assessment of the limits of autoregulation compared with the more clinically challenging transcranial Doppler methods .

Specific Aims:

1. To assess whether patients undergoing liver transplantation have impaired cerebral blood flow autoregulation.

2. To evaluate whether non-invasive monitoring of cerebral blood flow autoregulation with cerebral oximetry index and hemoglobin volume index can identify the lower limit of autoregulation within 10 mmHg compared with that measured with transcranial Doppler.

Conditions

Liver Failure; Liver Transplantation; Encephalopathy

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Autoregulation monitoring

Patients will be grouped into Meld Score

Near infrared spectroscopy monitoring

Intervention Type: OTHER

This is an observational study without interventions

Autoregulation monitoring

Intervention Type: OTHER

There are no interventions in this observational study

Interventions

Near infrared spectroscopy monitoring

This is an observational study without interventions

Intervention Type: OTHER

Autoregulation monitoring

There are no interventions in this observational study

Intervention Type: OTHER

Other Intervention Names

Cerebral oximetry index and hemaglobin volume index; Cerebral oximetry

Eligibility Criteria

Inclusion Criteria

-Age > 18 years old and undergoing liver transplantation.

Exclusion Criteria

• Clinical instability as judged by the attending physicians whereby autoregulation monitoring may interfere with clinical care.
• Women of child bearing potential require a negative urine human chorionic gonadotropin (HCG) test to be enrolled.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Johns Hopkins University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Charles W Hogue, MD

Role: PRINCIPAL_INVESTIGATOR

Johns Hopkins University

Locations

The Johns Hopkins Hospital

Baltimore, Maryland, United States

Countries

United States

References

Zheng Y, Villamayor AJ, Merritt W, Pustavoitau A, Latif A, Bhambhani R, Frank S, Gurakar A, Singer A, Cameron A, Stevens RD, Hogue CW. Continuous cerebral blood flow autoregulation monitoring in patients undergoing liver transplantation. Neurocrit Care. 2012 Aug;17(1):77-84. doi: 10.1007/s12028-012-9721-1.

Reference Type: DERIVED

PMID: 22644887 (View on PubMed)

Other Identifiers

NA_00051645

Identifier Type: -

Identifier Source: org_study_id