Microcirculatory changes and skeletal muscle oxygenation measured at rest by non-infrared spectroscopy in patients with and without diabetes undergoing haemodialysis

Abstract

IntroductionHaemodialysis has direct and indirect effects on skin and muscle microcirculatory regulation that are severe enough to worsen tolerance to physical exercise and muscle asthenia in patients undergoing dialysis, thus compromising patients' quality of life and increasing the risk of mortality. In diabetes these circumstances are further complicated, leading to an approximately sixfold increase in the incidence of critical limb ischaemia and amputation. Our aim in this study was to investigate in vivo whether haemodialysis induces major changes in skeletal muscle oxygenation and blood flow, microvascular compliance and tissue metabolic rate in patients with and without diabetes.MethodsThe study included 20 consecutive patients with and without diabetes undergoing haemodialysis at Sant Andrea University Hospital, Rome from March to April 2007. Near-infrared spectroscopy (NIRS) quantitative measurements of tissue haemoglobin concentrations in oxygenated [HbO2] and deoxygenated forms [HHb] were obtained in the calf once hourly for 4 hours during dialysis. Consecutive venous occlusions allowed one to obtain muscular blood flow (mBF), microvascular compliance and muscle oxygen consumption (mVO2). The tissue oxygen saturation (StO2) and content (CtO2) as well as the microvascular bed volume were derived from the haemoglobin concentration. Nonparametric tests were used to compare data within each group and among the groups and with a group of 22 matched healthy controls.ResultsThe total haemoglobin concentration and [HHb] increased significantly during dialysis in patients without and with diabetes. Only in patients with diabetes, dialysis involved a [HbO2], CtO2 and increase but left mVO2 unchanged. Multiple regression StO2 analysis disclosed a significant direct correlation of StO2 with HbO2 and an inverse correlation with mVO2. Dialysis increased mBF only in diabetic patients. Microvascular compliance decreased rapidly and significantly during the first hour of dialysis in both groups.ConclusionsOur NIRS findings suggest that haemodialysis in subjects at rest brings about major changes in skeletal muscle oxygenation, blood flow, microvascular compliance and tissue metabolic rate. These changes differ in patients with and without diabetes. In all patients haemodialysis induces changes in tissue haemoglobin concentrations and microvascular compliance, whereas in patients with diabetes it alters tissue blood flow, tissue oxygenation (CtO2, [HbO2]) and the metabolic rate (mVO2). In these patients the mVO2 is correlated to the blood supply. The effects of haemodialysis on cell damage remain to be clarified. The absence of StO2 changes is probably linked to an opposite [HbO2] and mVO2 pattern.

Haemodialysis Impairs the Human Microcirculation Independent from Macrohemodynamic Parameters

“…This may have been the case due to the lack of suitable techniques for clinical microvascular monitoring. Studies using skin and muscle oxygenation have recently shown impaired microvascular response in patients undergoing dialysis [10,11]. However, these techniques focus only on the peripheral microvasculature.…”

Reduced speed of microvascular blood flow in hemodialysis patients versus healthy controls: a coherent hemodynamics spectroscopy study

“…21,22 Previous NIRS studies in the hemodialysis unit have found a lower baseline cerebral tissue oxygenation in hemodialysis patients compared to healthy controls 23 and peritoneal dialysis patients, 24 and a greater hemoglobin concentration and reduced microvascular compliance measured in the calf muscle as a result of hemodialysis. 25 The effect of hemodialysis on the regional cerebral blood flow has been investigated with Xenon ventilation scintigraphy, where a mild reduction in cerebral blood flow was shown following as compared to before hemodialysis, 26 and with magnetic resonance imaging, where dialysis patients had lower cerebral blood flow than healthy controls. 23 The effect on large artery blood flow velocity has been assessed with transcranial Doppler ultrasound, revealing a significant decrease in blood flow velocity following dialysis as compared to prior to hemodialysis.…”

Use of Near Infrared Spectroscopy to Asses Remote Ischemic Preconditioning in Skeletal Muscle

“…In response to ischemia, it also allows evaluation of dynamic changes in microcirculation. Using NIRS, the changes in skeletal muscle oxygenation have been demonstrated in chronic heart failure patients at rest and during exercise [20,29], in patients undergoing haemodialysis [21], during abdominal aortic and cardiac surgery [30,31], and in patients with peripheral arterial disease [32], cirrhosis [33], septic shock [22,23], and metabolic myopathies [34]. NIRS has been already applied to demonstrate the effect of IPC on changes in myocardial oxygenation in dogs; IPC has been induced by repeated periods of coronary occlusion [35].…”

“…Near infrared spectroscopy (NIRS) has been used to assess peripheral microvascular function in a variety of clinical settings [19][20][21][22][23]. Illuminating an infrared band of 680-800 nm NIRS exploits the difference in absorption spectra between the oxygenated and deoxygenated hemoglobin and partly myoglobin and thus assesses the balance between local arterial supply and cellular oxygen consumption within the muscle tissue.…”