Superior Vena Cava and Its Relationship to Central Venous Pressure Measurements in Liver Transplantation

Completed

Conditions: Liver Failure

Registration Number: NCT02818218

Lead Sponsor: The Cleveland Clinic

Brief Summary: Consecutive patients undergoing liver transplant surgery will be included in the study. Before surgical incision, during the preanhepatic phase, during the anhepatic phase, during the postanhepatic phase and following closure of the deep fascial layer of the anterior abdominal wall simultaneous measurement of SVC diameter, SBC collapsibility index and CVP will be recorded.

Detailed Description: Central venous pressure (CVP) measured invasively through a central venous catheter in the internal jugular vein or through a right atrial port of a pulmonary artery catheter is commonly used during liver transplant surgery. CVP measurements at the SVC-RA junction are a function of circulating blood volume, right ventricle function, intrathoracic pressure. CVP measurements can also be affected by the presence of tricuspid regurgitation. Because central venous pressure measurements are determined by several factors and do not predict the response to subsequent fluid bolus administration, they are considered "static measures" and are poor indicators of fluid responsiveness.

Given the entirely intrathoracic location of the superior vena cava (SVC), its diameter and collapsibility with positive pressure ventilation it is a potentially attractive method of non-invasively estimating CVP.

SVC diameter and collapsibility index, dynamic measures of fluid responsiveness have been successfully utilized as echocardiographic indices for fluid responsiveness in ventilated septic patients. Whether SVC collapsibility is correlated with CVP measurements in liver transplant patients is not known.

Consecutive patients undergoing liver transplant surgery will be included in the study. Before surgical incision, during the preanhepatic phase, during the anhepatic phase, during the postanhepatic phase and following closure of the deep fascial layer of the anterior abdominal wall simultaneous measurement of SVC diameter, SBC collapsibility index and CVP will be recorded.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 58

Inclusion Criteria

18 years of age
undergoing liver transplantation surgery (cadaveric and living related)

Exclusion Criteria

Contraindication to Transesophageal echocardiography

Study & Design

Study Type: OBSERVATIONAL

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Central Venous Pressure (CVP)	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	Central Venous Pressure (CVP) reflects the amount of blood returning to the heart (venous return) and the ability of the heart to pump the blood into the arterial system. It was captured electronically via an automated record-keeping system. CVP were recorded by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall. Low CVP (\< 2 mmHg) suggests hypovolemia, dehydration, or blood loss, while normal CVP (2-8 mmHg) indicates balanced fluid status. A high CVP (\> 8 mmHg) may indicate fluid overload, right heart failure, pulmonary hypertension, or cardiac tamponade.
Correlation of Central Venous Pressure (CVP) and Maximum Diameter of Superior Vena Cava (SVC)	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	The diameter of the Superior Vena Cava (normal diameter: 12-22 mm) ) was obtained using transesophageal echocardiography (TEE). Central Venous Pressure (CVP) and SVC were recorded simultaneously by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall.
Correlation of Central Venous Pressure (CVP) and Superior Vena Cava (SVC) Collapsibility Index	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	The Superior Vena Cava (SVC) Collapsibility Index is used to assess intravascular volume status and fluid responsiveness. The Superior Vena Cava (SVC) collapsibility index was obtained from (Maximum Diameter-Minimum Diameter)/(Maximum Diameter)\*100%. Central Venous Pressure (CVP) and SVC were recorded simultaneously by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall. The interpretation of the SVC Collapsibility Index is categorized as follows: \< 20% indicates low collapsibility, suggesting adequate or high intravascular volume; 20-36% represents an indeterminate zone, requiring additional assessment to determine fluid responsiveness; and \> 36% reflects high collapsibility, suggesting hypovolemia or significant fluid deficit.
Correlation of Central Venous Pressure (CVP) and Minimum Diameter of Superior Vena Cava (SVC)	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	The diameter of Superior Vena Cava (normal diameter: 12-22 mm) ) was obtained using transesophageal echocardiography (TEE). Central Venous Pressure (CVP) and SVC were recorded simultaneously by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall.

Secondary Outcome Measures

Name	Time	Method
Cardiac Index	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	The Cardiac Index measures the efficiency of the heart's pumping function (normal range: 2.6 to 4.2 L/min/m2). It was captured electronically via an automated record-keeping system. Cardiac Index was recorded by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall.
Correlation of Cardiac Index (CI) and Superior Vena Cava (SVC) Collapsibility Index	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	The Superior Vena Cava (SVC) Collapsibility Index is used to assess intravascular volume status and fluid responsiveness. The Superior Vena Cava (SVC) collapsibility index was obtained from (Maximum Diameter-Minimum Diameter)/(Maximum Diameter)\*100%. Central Venous Pressure (CVP) and SVC were recorded simultaneously by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall. The interpretation of the SVC Collapsibility Index is categorized as follows: \< 20% indicates low collapsibility, suggesting adequate or high intravascular volume; 20-36% represents an indeterminate zone, requiring additional assessment to determine fluid responsiveness; and \> 36% reflects high collapsibility, suggesting hypovolemia or significant fluid deficit.
Correlation of Cardiac Index (CI) and Minimum Diameter of Superior Vena Cava (SVC)	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	The diameter of the Superior Vena Cava (normal diameter: 12-22 mm) ) was obtained using transesophageal echocardiography (TEE). Cardiac Index and Superior Vena Cava (SVC) were recorded simultaneously by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall.
Correlation of Cardiac Index (CI) and Maximum Diameter of Superior Vena Cava (SVC)	From the time patients enter the operating room to leaving the operating room, up to 24 hours.	The diameter of the Superior Vena Cava (normal diameter: 12-22 mm) ) was obtained using transesophageal echocardiography (TEE). Cardiac Index and Superior Vena Cava (SVC) were recorded simultaneously by experienced anesthesiologists with expertise and qualifications in TEE at five key time points: before surgical incision, start of the preanhepatic phase, start of the anhepatic phase, start of the postanhepatic phase, and after closure of the deep fascial layer of the anterior abdominal wall.