Association between hepatic oxygenation on near-infrared spectroscopy and clinical factors in patients undergoing hemodialysis

Abstract

The hepato-splanchnic circulation directly influences oxygenation of the abdominal organs and plays an important role in compensating for the blood volume reduction that occurs in the central circulation during hemodialysis (HD) with ultrafiltration. However, the hepato-splanchnic circulation and oxygenation cannot be easily evaluated in the clinical setting of HD therapy. We included 185 HD patients and 15 healthy volunteers as the control group in this study. Before HD, hepatic regional oxygen saturation (rSO2), a marker of hepatic oxygenation reflecting the hepato-splanchnic circulation and oxygenation, was monitored using an INVOS 5100c oxygen saturation monitor. Hepatic rSO2 was significantly lower in patients undergoing HD than in healthy controls (56.4 ± 14.9% vs. 76.2 ± 9.6%, p < 0.001). Multivariable regression analysis showed that hepatic rSO2 was independently associated with body mass index (BMI; standardized coefficient: 0.294), hemoglobin (Hb) level (standardized coefficient: 0.294), a history of cardiovascular disease (standardized coefficient: -0.157), mean blood pressure (BP; standardized coefficient: 0.154), and serum albumin concentration (standardized coefficient: 0.150) in Model 1 via a simple linear regression analysis. In Model 2 using the colloid osmotic pressure (COP) in place of serum albumin concentration, the COP (standardized coefficient: 0.134) was also identified as affecting hepatic rSO2. Basal hepatic oxygenation before HD might be affected by BMI, Hb levels, a history of cardiovascular disease, mean BP, serum albumin concentration, and the COP. Further prospective studies are needed to clarify whether changes in these parameters, including during HD, affect the hepato-splanchnic circulation and oxygenation in HD patients.

Effects of percutaneous transluminal angioplasty and associated factors in access hand oxygenation in patients undergoing hemodialysis

“…Hb plays an important role as a transporter for carrying oxygen to systemic tissues, and tissue oxygenation is associated with Hb level. The maintenance of Hb level could contribute to maintaining access hand oxygenation, similar to the positive correlation between Hb levels and cerebral or hepatic rSO 2 values 23,25 . Serum Cr is generally an indicator of kidney function and is also a metabolic product derived from the muscle.…”

“…Tissue oxygenation evaluation was recently performed in patients undergoing HD, and rSO 2 was investigated in the brain, liver and muscle 10,[23][24][25] . Low tissue oxygenation may have negative influence on HD patients.…”

Factors affecting intradialytic hepatic oxygenation: Associations between ultrafiltration rate and changes in systemic blood pressure

“…Hepatic rSO 2 , a marker of hepatic oxygenation, was monitored using an INVOS 5100c saturation monitor (Covidien Japan, Tokyo, Japan), as described previously. 8 This instrument uses a light-emitting diode that transmits near-infrared light at two wavelengths (735 and 810 nm) to measure oxygenated and deoxygenated hemoglobin (Hb), along with two silicon photodiodes that act as light detectors. The ratio of the signal strengths of oxygenated Hb to that of total Hb (oxygenated + deoxygenated Hb) was calculated, and the corresponding percentage was recorded as a single numerical value representing the rSO 2 level.…”

“…7 So far, hepatic rSO 2 before HD is significantly and positively associated with mean BP. 8 In addition, hepatic rSO 2 is stable during HD, 9 whereas it decreases at the onset of IDH. 10,11 According to previous reports, the burden of the HD procedure, including ultrafiltration and changes in systemic BP, could lead to a reduction of the blood volume in the hepato-splanchnic circulation during HD; therefore, a decrease in intradialytic hepatic oxygenation would be expected in response to these influences.…”

The Potential Use of Near- and Mid-Infrared Spectroscopy in Kidney Diseases

“…Hepato-splanchnic circulation directly influences abdominal organ oxygenation and is important in compensating for the blood volume reduction that occurs in the central circulation during HD with ultrafiltration. In a study [ 122 ] of 185 HD patients and 15 healthy volunteers, rSO 2 , a hepatic oxygenation marker that reflects hepato-splanchnic circulation and oxygenation, was measured using an INVOS 5100c oxygen saturation monitor. Hepatic rSO 2 levels were significantly lower in patients on HD than in healthy controls (56.4 ± 14.9% vs. 76.2 ± 9.6%, p < 0.001).…”