Autoregulation Assessment During Liver Transplantation

Non-Invasive Assessment of Cerebral Blood Flow Autoregulation in Patients Undergoing Liver Transplantation

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.

Study Overview

• Status: Completed
• Conditions: Liver Failure; Liver Transplantation; Encephalopathy
• Intervention / Treatment: Other: Near infrared spectroscopy monitoring; Other: Autoregulation monitoring

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.

• Study Type: Observational
• Enrollment (Actual): 10

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21287
      • The Johns Hopkins Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

In this pilot study we will enroll 20 patients undergoing orthotopic liver transplantation at The Johns Hopkins Hospital. Patients will receive standard care during the procedure. Study related procedures are non-invasive and observational. There will be no interventions based on the results of the study data. The study will include only the immediate operative period. The patients will have transcranial Doppler monitoring and near infrared spectroscopy monitoring during surgery beginning before anesthesia induction and continued until the end of surgery.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Autoregulation monitoring; Patients will be grouped into Meld Score	Other: Near infrared spectroscopy monitoring; This is an observational study without interventions; Other Names: Cerebral oximetry index and hemaglobin volume index; Other: Autoregulation monitoring; There are no interventions in this observational study; Other Names: Cerebral oximetry

Collaborators and Investigators

• Sponsor: Johns Hopkins University
• Investigators: Principal Investigator: Charles W Hogue, MD, Johns Hopkins University

Publications and helpful links

General Publications

• 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.

Study record dates

Study Major Dates

• Study Start: September 1, 2011
• Primary Completion (Actual): September 1, 2012
• Study Completion (Actual): September 1, 2012

Study Registration Dates

• First Submitted: August 26, 2011
• First Submitted That Met QC Criteria: August 29, 2011
• First Posted (Estimate): August 30, 2011

Study Record Updates

• Last Update Posted (Actual): August 22, 2017
• Last Update Submitted That Met QC Criteria: August 17, 2017
• Last Verified: August 1, 2017

More Information

Terms related to this study

• Keywords: liver transplantation; liver failure
• Additional Relevant MeSH Terms: Digestive System Diseases; Central Nervous System Diseases; Nervous System Diseases; Liver Diseases; Liver Failure; Hepatic Insufficiency; Brain Diseases
• Other Study ID Numbers: NA_00051645