Reducing symptoms during hemodialysis by continuously monitoring the hematocrit.

Previous studies have demonstrated that patients on hemodialysis develop intradialytic symptoms when the blood volume decreases to a critical level. Using a continuous monitor (CRIT-LINE; In-Line Diagnostics, Riverdale, UT) to determine the instantaneous hematocrit and blood volume, we observed that certain intradialytic symptoms occurred at a patient-specific hematocrit. In the present study, we exploited this hematocrit threshold concept to decrease the occurrence of lightheadedness, cramping, and nausea, regardless of blood pressure changes.

Determination of circulating blood volume by continuously monitoring hematocrit during hemodialysis.

Dialysis-induced hypovolemia occurs because the rate of extracorporeal ultrafiltration exceeds the rate of refilling of the blood compartment. The purpose of this study was to evaluate a method for calculating circulating blood volume (BV) during hemodialysis (HD) from changes in hematocrit (Hct) shortly (2 to 10 min) before and after ultrafiltration (UF) was abruptly stopped. Hct was monitored continuously during 93 HD treatment sessions in 16 patients by an optical technique and at selected times by centrifugation of blood samples.

Hematocrit as an indicator of blood volume and a predictor of intradialytic morbid events.

Hematocrit (H) levels can change during hemodialysis, and these changes in H are inversely related to changes in blood volume (BV). The objectives of this study were to determine whether mean arterial pressure (MAP) decreases with decreasing BV and rising H during hemodialysis, and to determine the relationship between dialysis induced intravascular volume depletion and intradialytic morbid events (IME), defined as hypotension, cramping, or lightheadedness that led to dialysis staff intervention. We monitored H continuously using a noninvasive optical technique in 93 hemodialysis sessions in 16 patients.