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Intravenous vitamin K 1 prior to orthotopic heart transplantation: effects in vivo and in vitro
Author(s) -
BARNETTE R. E.,
WENDLING W. W.,
SCHWEIGER J. W.,
BRISTER N. W.,
SCHARTEL S. A.,
CHEN D.,
SHUMAN C. A.,
MCCLURKEN J. B.,
JEEVANANDAM V.
Publication year - 1997
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1997.tb04616.x
Subject(s) - medicine , perioperative , activated clotting time , transplantation , vitamin , warfarin , anesthesia , cardiac index , hemodynamics , anticoagulant , surgery , cardiac output , atrial fibrillation
Background: Vitamin Kj is used to reverse warfarin's anticoagulant action. It is unclear whether intravenous vitamin K 1 is safe or efficacious prior to urgent cardiac surgery. Methods: We retrospectively and prospectively examined the effects of preoperative intravenous vitamin K 1 in vivo (administered for warfarin reversal immediately before heart transplantation) on intraoperative blood product utilization, hemodynamics and coagulation parameters. We also determined the direct effects of vitamin K, in vitro on rings of human saphenous vein and internal mammary artery. Results: In the retrospective limb, 29 of 67 patients were administered vitamin K 1 preoperatively via slow intravenous infusion. Vitamin K 1 administration produced no adverse outcome but did not affect subsequent perioperative use of blood products. In the prospective limb (n=10), vitamin K x significantly ( P ≤0.01, Student t‐test) altered mean arterial pressure (from 85±15 to 76±16 mmHg), systemic vascular resistance (from 1364±308 to 1078±252 dyn s cm ‐5 ), and cardiac index (from 2.3±0.3 to 2.7±0.3 L/min/m 2 ) (mean±SD). Significant decreases in prothrombin time (19.8±2.7 to 17.7±1.8 s) and ac tivated clotting time (164±26 to 137±24 s) were observed at 60 min. In vitro , vitamin K 1 (10 ‐7 to 10 ‐4 M) had no effect on the tone of noradrenaline‐constricted rings. Conclusions: Vitamin K 1 administered by intravenous infusion prior to heart transplantation, did not alter subsequent perioperative blood product administration. Vitamin K 1 rapidly reversed the anticoagulant effect of warfarin and produced modest hemodynamic changes. The decrease in systemic vascular resistance is probably not due to a direct effect of vitamin K 1 on vascular smooth muscle.