CC: Left Arm Swelling and Pain
HPI: 84 y/o Caucasian male with history of CAD s/p CABG, HTN, HLD, CKD stage 2, and BPH presented with a 2 day history of swelling and excruciating pain in the L arm following a routine lab draw from a vein in the L hand. Swelling had begun at the site and expanded to include the entirety of his arm. Overlying bruising emerged with increasing pain. He also noted bruising of the internal thighs incidentally but denied trauma at either site. He had not history of bleeding diathesis diagnosed in him or a family member and had no reported easy bruising or bleeding previously. He had no recent medication changes. Physical exam was notable for a swollen and tender L arm with erythema and extensive ecchymoses extending from the wrist to the elbow. Range of motion was intact as were peripheral pulses, even in the affected arm. Notably, the patient had bruising on the extremities and on his trunk and abdomen. Physical exam was not concerning for compartment syndrome of the arm given the aforementioned findings, though the team closely monitored for signs of impending arterial compression. Initial laboratory evaluation revealed an elevated partial thromboplastin time (PTT) but a normal prothrombin time (PT) and international normalized ratio (INR). Mixing studies were performed, and the PTT did not correct suggesting the presence of an inhibitor. Factor VIII levels were checked and were significantly lower than the lower limit of normal. Factor VIII inhibitor level was detected at 35 Bethesda Units. This confirmed the presence of an acquired factor VIII inhibitor.
Morning Report Pearls:
Bleeding disorders can be divided primarily into broad categories, those that affect primary hemostasis and those that affect secondary hemostasis. Disorders of both primary and secondary hemostasis can be either acquired or inherited.
Some Causes of Primary Hemostatic Disorders, Acquired
Some Causes of Primary Hemostatic Disorders, Inherited
Some Causes of Secondary Hemostatic Disorders, Acquired
Some Causes of Secondary Hemostatic Disorders, Inherited
When evaluating a patient with a suspected bleeding disorder, physical exam can be very informative in narrowing the diagnosis. Patients with primary hemostatic disorders (platelets) tend to present with mucosal or cutaneous bleeding; epistaxis or gingival bleeding; petechiae, especially in dependent areas; immediate bleeding post-injury; and menorrhagia/metomenorrhoagia. Patients with secondary hemostatic disorders (coagulation factors) tend to present with large palpable ecchymoses; hemorrhage into joints or muscles; delayed bleeding given preservation of platelet function and number; and post-operative bleeding.
Secondary hemostatic disorders affect PT, INR, and PTT depending on the factors involved. Whenever PT or PTT are affected due to concern for bleeding diathesis, a mixing study is appropriate. In this case, PTT was prolonged. An example of a PTT mixing study is below:
The results of this mixing study led to concern for an acquired Factor VIII inhibitor, which was confirmed. Of note, lupus anticoagulant was ruled out on lab testing.
Causes of Acquired Factor VIII Inhibitor