A while ago Seth Dillingham wrote two Google modules for me: Allowable Blood Loss and BMI Calculator. Well, I still have a hard time finding them on Googles own module site, but I can find them both on googlemodules.com--the 'Unofficial Google Modules Site'.
I wanted to pass along another use for the allowable blood loss calculator--estimating surgical blood loss. Anesthetists are asked to estimate the volume of surgical blood loss that occurs during a procedure on their anesthetic record. Surgeons will often attempt to influence that figure downward by volunteering their own estimate of blood loss (often not grounded in reality) in the hope of getting me to go along with it.
In large blood loss cases where I've been following the hematocrit I use the formula to calculate the actual blood loss. For example, if a 100 kg male started with a hematocrit of 0.40 and wound up with a hematocrit of 0.32 I calculate their blood loss as 1600 cc. No arguments.