ITC Hemochron Response Whole Blood Coagulation System - Manual (Page 4)

4
Blood Volume Calculation
Blood volume can either be directly entered, or it can be calculated from the patient's height and weight.
The system automatically calculates the blood volume once values for the patient's height, weight, and
gender have been entered, using the algorithm described by Allen, et al.
1 If the patient's blood volume is
entered by the operator, that value is used instead.
If the entered weight is less than 20 kg, the message OUT OF RANGE WEIGHT is displayed. The blood
volume for the patient must then be manually entered.
Bolus Heparin Dose Calculation (Heparin Mode)
The bolus heparin dose is calculated using the baseline ACT, HRT, targeted ACT and patient blood volume,
based upon standard dose response techniques described by Bull, et al.
2
The bolus heparin dose is calculated if the baseline ACT and current HRT values are within these ranges:
• The baseline ACT must be within 70 to 250 seconds.
• The current HRT must be within 200 to 1,500 seconds, and at least 100 seconds greater than
the baseline ACT.
Note: If a user-entered value is outside these ranges, an error message is displayed. If the calculated
bolus heparin dose is greater than 6.7 units per mL of blood volume (or 5 mg/kg by body weight), a
warning message is displayed.
Additional Heparin Dose Calculation (Additional Heparin Mode)
After the bolus heparin dose is administered, any additional heparin doses can be calculated using the
current ACT and heparin dose given, as described by Bull, et al.
2
The additional heparin dose is calculated if the post bolus ACT, baseline ACT, target ACT, and current ACT
values are within these ranges:
• The post bolus ACT must be greater than the baseline ACT.
• The target ACT must be greater than the current ACT.
Note: If the values are outside these ranges, a message is displayed.
Protamine Dose Calculation (Protamine Mode)
The protamine dose is calculated using the PRT (or PDA-O), the most recent ACT, targeted ACT value and
the patient’s blood volume, as described by Bull, et al.
2
When a PRT test is run, the protamine dose is calculated if the Current PRT and Status ACT values are
within these ranges:
• The current PRT must be within 70 to 800 seconds.
• The status ACT must be within 200 to 1,500 seconds and greater than the PRT.
Note: If the values are outside these ranges, an error message is displayed.
When a PDA-O test is run, the protamine dose is calculated if the Current PDA-O and Status ACT values are
within these ranges:
• The current PDA-O must be within 70 to 300 seconds.
• The status ACT must be within 150 to 1,500 seconds and greater than the PDA-O.
Note: If the values are outside these ranges, an error message is displayed.
If the calculated protamine dose is greater than 500 mg, a warning message is displayed. If the calculated
protamine dose is greater than 800 mg, the message Dose >800 mg is displayed in place of the
protamine dose.