What is this crash crit and how can I use it, if the pts hct is constently changing from EPO doses, bleeding etc...

The "Crash-Crit" or Hematocrit Threshold is a physiological principal based upon the morbidity that occurs at a patient specific critical blood volume.

As the blood volume of a patient is reduced (i.e. during hemodialysis)the Hct increases (same red blood cell mass/less fluid). Eventually the blood volume reaches a level at which blood pressure is unable to be maintained, cramping occurs, etc. This blood volume level is "marked" by a very specific Hct. Over time this Hct (the Crash-Crit or Hct Threshold) is very repeatable.

Blood transfusions, blood loss, signifigant recirculation, new EPO regime, etc. - all change the red blood cell mass which in turn may effect (in varying degrees) this Hct Threshold. In the majority of cases however this value is relatively stable over long periods of time (months). It therefore allows the clinician instant assessment of the fluid status of the intravascular compartment. For example, a patient has consistently experienced cramping as his/her Hct approaches 37. When the treatment starts the Crit-Line shows a Hct of 31. The clinician immediately knows that the patient can most likely tolerate fluid removal until the Hct approaches 37 - a blood volume reduction of about 16%- without experiencing symptoms of hypovolemia. Using the Crit-Line to continously monitor the Hct the clinican adjusts the UF to optimize (maximize) fluid removal but avoid exceeding the 37 Hct threshold. Maximum fluid - minimum morbidity.

The next treatment the patient presents with a starting Hct of 35. Only a 5% reduction in BV brings the Hct to 37 - the patients Hct threshold. UF is adjusted as necessary to maximize fluid removal but also keep the Hct below 37. On this day the patient didn't have as much fluid in the intravascular space - to much Na over the weekend?, and wasn't shifting the fluid as quickly. The treatment was adjusted prior to having the patient experience symptoms.

These cases emphasize that regardless of hydration status the clinician is able to use the information provided by the Crit-Line and proactively adjust the UF rate to maximize fluid removal based upon patient feedback during that treatment.

Many literature references exist verifying this concept. Please contact me if you wish to review them.

The Crit-Line's rapidly increasing popularity is expanding the concept of Hct threshold. Only the Crit-Line is able to utilize this physiological parameter.