INCREASED ACCURACY AND PRECISION OF HEPARIN AND PROTAMINE DOSING REDUCES BLOOD-LOSS AND TRANSFUSION IN PATIENTS UNDERGOING PATIENTS CARDIACOPERATIONS

Individual aspects of heparin or protamine dosing have been better con trolled than previously as useful tests have become available, Althoug h many variables including drug potency, drug source, and individual p atient response have been separately identified, there has not been an attempt to integrate them into a single management strategy: This stu dy was undertaken to learn whether more precise control of drug variab les and patient response would affect blood loss and transfusion requi rements, Adult patients having primary cardiac operations were prospec tively randomized into two groups, A control group received heparin an d protamine by conventional methods, The test group received heparin a nd protamine according to in vitro predictive tests integrating drugs, tests, and patient response, Supplemental protamine was given in this group only if heparin was specifically found by testing, Anticoagulat ion in all patients was maintained at an activated coagulation time gr eater than 400 seconds, and any other treatment for bleeding was at th e discretion of the clinical team caring for the patients. Testing and treatment for both groups followed routine practice after patient arr ival in the intensive care unit. Test patients received slightly more heparin and a markedly lower dose of protamine than the control patien ts, Testing identified patients with decreased heparin sensitivity (pr eoperative heparin therapy) and correctly predicted the effective hepa rin dose, Supplemental protamine was given twice as often to control p atients and frequently when no heparin was detectable (retrospectively ). Test patients exhibited less 24-hour chest tube drainage (671 ml ve rsus 1298 ml) and fewer patients received transfusion (9/22 versus 18/ 24) with fewer donor exposures (22/22 versus 101/24), The management s trategy used for heparin and protamine added accuracy and precision, w hich was associated with improved hemostasis, Although the observation is valid, the mechanism or mechanisms are not completely clear, Never theless, it is reasonable to apply basic pharmacologic principles and establishment of consistent, predictable protocols that are beneficial , It is against this background that the efficacy of additional drugs or equipment should be assessed. It is quite possible that only margin al if any improvement in hemostasis may be found in patients having pr imary, uncomplicated cardiac operation with the addition of more costl y drugs or equipment.