Intramuscular Hematoma

Heparin may be given by intermittent IV administration, continuous IV infusion, and the SC route. Intramuscular administration is avoided because of die possibility of the development of local irritation, pain, or hematoma (a collection of blood in die tissue). A solution of dilute heparin may be used to maintain patency of an IV site used for intermittent administration of any drug given by die IV route ... 

Immediate administration of 100 meg to 1 mg vitamin K subcutaneously or intravenously, followed by administration of FFP as necessary. Vitamin K administration via the intramuscular route may induce hematoma owing to coagulopathy, and intravenous administration should be slow because it has been associated with anaphylaxis. Prothrombin complex concentrate (PCC) at minimum dose of 50 units/kg should be given for life-threatening bleeding.27,28... 

UFH must be given parenterally, preferably by the IV or subcutaneous (SC) route. Intramuscular administration is discouraged because absorption is erratic and it may cause large hematomas. 

When used in therapeutic doses, dimercaprol is associated with a high incidence of adverse effects, including hypertension, tachycardia, nausea, vomiting, lacrimation, salivation, fever (particularly in children), and pain at the injection site. Its use has also been associated with thrombocytopenia and increased prothrombin time—factors that may limit intramuscular injection because of the risk of hematoma formation at the injection site. Despite its protective effects in acutely intoxicated animals, dimercaprol may redistribute arsenic and mercury to the central nervous system, and it is not advocated for treatment of chronic poisoning. Water-soluble analogs of dimercaprol—unithiol and succimer—have higher therapeutic indices and have replaced dimercaprol in many settings. 

A 65-year-old man, with metastatic carcinoma of the prostate was treated with flutamide 250 mg/day orally followed after 6 days by 7.5mg leuprolide intramuscularly. Two days later he developed bleeding and hematomas. His hemoglobin fell from 12.4 to 7.8 g/dl and he had a disseminated intravascular coagulopathy. 

Continuous intravenous administration of heparin is accomplished via an infusion pump. After an initial bolus injection of 80-100 units/kg, a continuous infusion of about 15-22 units/kg/h is required to maintain the aPTT at 2-2.5 times control. Patients with acute pulmonary emboli often require larger doses than these during the first few days because of binding to a variety of acute phase proteins, such as factor VIII and von Willebrand factor, and increased heparin clearance. Subcutaneous administration of heparin, as in low-dose prophylaxis, is achieved with 5000 units every 8-12 hours. Because of the danger of hematoma formation at the injection site, heparin must never be administered intramuscularly. 

Intramuscular injection of hyaluronidase (150 U) decreases and softens hematoma at an angiographic puncture site [127],... 

Heparin is administered both parenterally and subcutaneously. Oral, rectal, sublingual absorption is poor due to heparin s large size. Intramuscular administration leads to irregular absorption and hematoma development at the site of injection. 

DOSAGE The usual adult dose of warfarin (COUMADIN) is 5 mg/day for 2-4 days, followed by 2-10 mg/day as indicated by measurements of the INR. A lower initial dose should be given to patients with an increased risk of bleeding, including the elderly age correlates with increased sensitivity to oral anticoagulants. Warfarin usually is administered orally but also can be given intravenously without dose modification. Intramuscular injection is not recommended because of the risk of hematoma formation. 

B. Intramuscular administration in anticoagulated patients may cause large, painful hematomas. This can be avoided by using oral or subcutaneous routes. 

Methylsalicylate Topical methylsalicylate 50% has been reported to have enhanced the action of warfarin in a 53-year-old man, resulting in a large right retroperitoneal hematoma and right iliac intramuscular hematoma after trauma [47 ]. 

There are three main complications of muscle tear cysts and myositis ossificans and, more rarely, calcific myonecrosis (Peetrons 2002). Intermuscular and intramuscular cysts may be encountered after muscle trauma as well-defined echo-free masses with posterior acoustic enhancement. These cysts have an elongated shape and represent the residue of a local hematoma. Their most common location is the calf (see Chapter 15). In selected cases, they may require percutaneous needle evacuation. Calcific myonecrosis is a space-occupying calcified mass that typically develops in the anterior compartment of the leg late after a closed lower extremity... 

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