Central Versus Peripheral Invasive Arterial Blood Pressure Monitoring in Liver Transplant Surgery

Abstract

IntroductionInvasive blood pressure monitoring is essential in liver transplant surgery due to expected major hemodynamic shifts. The use of central versus peripheral arterial access, however, is institution-dependent, which can affect clinical decisions regarding vasopressor therapy. Although there are studies that demonstrate inconsistencies based on arterial cannulation sites, few studies have compared femoral and radial artery blood pressures in patients undergoing liver transplant surgery. To our knowledge, there are no studies investigating the differences between continuous minute-to-minute femoral and radial artery measurements during all three phases of liver transplant surgery. ObjectiveThe main objective of this study was to evaluate for any differences between central and peripheral blood pressure measurements in liver transplant surgery and to assess for any correlation between vasopressor infusion dose and femoral-arterial pressure differences. MethodsIn this retrospective study, we reviewed and studied the data of 61 patients with American Society of Anesthesiologists (ASA) grade 4 who underwent liver transplant surgery at Loma Linda University Medical Center between January and December of 2019. All patients had both femoral and radial arterial lines placed for liver transplant surgery. Femoral and radial arterial blood pressure values were obtained continuously over 60 minutes in the pre-anhepatic phase, 45 minutes during the anhepatic phase, and 60 minutes into the neo-hepatic phase. Vasopressor infusion doses were also recorded for each patient during these time frames. ResultsThis pilot study found statistically significant differences between the mean femoral and radial systolic blood pressure (SBP; p < 0.0001), diastolic blood pressure (DBP; p < 0.0001), and mean arterial pressure (MAP; p < 0.0001) during all phases of liver transplantation. The mean SBP and MAP differences between femoral and radial arteries were highest (femoral blood pressure reading higher than radial blood pressure measurements) in the late anhepatic and early neo-hepatic phases with SBP differences of 20.8 ± 0.8 mmHg and 22.8 ± 0.8 mmHg, respectively, and MAP differences of 10.0 ± 0.4 mmHg and 9.8 ± 0.4 mmHg, respectively. Higher vasopressor infusion doses were strongly associated with greater differences in femoralradial SBP and MAP measurements (r = 0.69 for vasopressin, 0.68 for norepinephrine, and 0.68 for epinephrine; p < 0.0001) during the anhepatic phase. ConclusionsPeripheral invasive blood pressure monitoring may result in underestimation of the central blood pressure, as was seen in all phases of liver transplantation. This may lead to excessive vasopressor use with potentially adverse effects. Although the cause for the difference between femoral and radial artery measurements is unclear, increasing vasopressor infusion dosages appears to contribute. Femoral artery blood pressure monitoring allows clinicians to interpret hemodynamic status and administer appropriate vasopressors more accurately.

Hemodynamic monitoring in liver transplantation ‘the hemodynamic system’

“…The invasive blood pressure (IBP) is the clinical reference method for arterial blood pressure (ABP) monitoring providing accurate beat-to-beat monitoring and is the standard of care in liver transplantation [12,18,34,35,105,116]. The ABP values vary according to the artery monitored [12,18,105,117]. The ABP can be divided into central and peripheral ABPs with the femoral and brachial the…”

“…The radial systolic blood pressure (SBP) is typically higher than the aortic SBP due to peripheral wave reflection, however, this relationship is reversed in critically ill patients including liver transplantation patients [12,34,35,105]. The radial SBP underestimates the central (femoral) SBP during all stages of liver transplantation and that is most pronounced immediately after reperfusion [12,115]. One study showed that the incidence of PRS was 80% when the radial ABP was monitored versus 50% when the femoral ABP or the noninvasive blood pressure (NIBP) were monitored [115].…”

“…One study showed that the incidence of PRS was 80% when the radial ABP was monitored versus 50% when the femoral ABP or the noninvasive blood pressure (NIBP) were monitored [115]. This may lead to excessive vasopressor use with potentially adverse effects [12,34,85]. High-dose pressors tend to increase the peripheral to central SBP discrepancy starting a vicious cycle that can increase morbidity and mortality [12,105].…”

“…This may lead to excessive vasopressor use with potentially adverse effects [12,34,85]. High-dose pressors tend to increase the peripheral to central SBP discrepancy starting a vicious cycle that can increase morbidity and mortality [12,105].…”

“…There is no consensus among liver transplantation centers on the exact site of arterial cannulation and on how many arterial lines are needed for a liver transplantation [12,105]. Some centers consider radial ABP monitoring unreliable and monitor central (femoral or brachial) ABP [105].…”