Bleeding Complications in the Patient with Cardiac Disease Following Thrombolytic and Anticoagulant Therapies

The effect of chitosan (poly-N-acetyl glucosamine) on lingual hemostasis in heparinized rabbits

PURPOSE

The purpose of this study was to evaluate the effect of chitosan on lingual hemostasis in rabbits whose coagulation pathway had been impaired by administration of intravenous heparin.

MATERIALS AND METHODS

Bleeding times were measured for bilateral (15 mm x 2 mm) tongue incisions in 10 New Zealand white rabbits. Using a randomized, blinded experimental design, one incision in each animal was treated with chitosan, and the other was treated with the control vehicle without chitosan. Activated coagulation times and extraoral bleeding times were measured for each animal before, during, and after heparinization.

RESULTS

Intravenous infusion of heparin more than tripled the mean activated coagulation time and increased mean systemic bleeding time by 40%. In this heparinized animal model, lingual incisions receiving the experimental substance showed a 43% improvement in bleeding time as compared with lingual incisions receiving the control solution (P< or =.001). Chitosan treatment brought bleeding time of the lingual incision for heparinized animals within the normal range. Scanning electron microscopic evaluation of the incisions treated with chitosan showed an altered red blood cell morphology and an unusual affinity between erythrocytes.

CONCLUSIONS

Topical application of chitosan to lingual incisions effectively decreased intraoral bleeding time in a therapeutically anticoagulated (heparinized) rabbit model. Chitosan facilitated lingual hemostasis, possibly through interaction with erythrocytes, linking them together to establish a cellular clot or hemostatic plug.

Case managing heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) and its two subtypes, early onset (Type I) and delayed onset (Type II), are becoming an increasing concern in acute care. Also called "white clot syndrome," this condition can lead to thrombosis and loss of limb. Alternatives to heparin therapy, such as low molecular weight heparin, are discussed as ways to decrease HIT. An algorithm has been developed to guide identification and monitoring of patients at risk for HIT. The article presents the expanded role of the clinical nurse specialist as case manager in clinically managing patients with actual or potential HIT. The case manager's role for patients receiving heparin lies in increasing the awareness of this condition among all clinicians and serving as a resource for current information regarding its prevention, diagnosis, and treatment.

Ancrod: the use of snake venom in the treatment of patients with heparin-induced thrombocytopenia and thrombosis undergoing coronary artery bypass grafting: nursing management

Heparin-induced thrombocytopenia and thrombosis, also known as heparin-associated thrombocytopenia and thrombosis, was diagnosed in a 73-year-old man who had sustained a pelvic fracture, which was complicated by a left, deep-vein thrombosis. Heparin was administered and thrombocytopenia and arterial thrombosis of his left foot developed, which required amputation of three lateral toes. Four years later, the patient experienced a heart attack, and subsequently postinfarction angina developed, which was refractory to treatment with aspirin, nitrates, and beta-blockers. He was referred to a large, 750-bed teaching hospital for cardiac catheterization and possible coronary artery bypass grafting. An alternative treatment was needed for rapid anticoagulation. Ancrod, snake venom from the Malayan pit viper, was used to lower plasma fibrinogen levels, which allowed successful cardiac catheterization and coronary artery bypass grafting. We present a case study of the successful treatment of this patient with use of ancrod, and the nursing management for patients with heparin-induced or heparin-associated thrombocytopenia and thrombosis receiving this drug.