While bleeding symptoms may be commonly seen by physicians of multiple specialties, these symptoms frequently belie an underlying yet undiagnosed congenital or acquired bleeding disorder. While it represents a rare bleeding disorder (1-4 cases per 1 million population per year), acquired hemophilia (AH) is a potentially life-threatening cause of unexplained recent-onset or acute bleeding manifested by an abnormal activated partial thromboplastin time (aPTT) that does not correct with 1:1 mixing with normal plasma. Given the rarity of AH, combined with the general lack of familiarity of non-hematologists with this condition, diagnosis of AH poses a clinical challenge, even in patients presenting with a clear picture of bleeding with an isolated prolonged aPTT.
Actively practicing physicians within the specialties of hematology, hematology/oncology, emergency medicine, geriatrics, internal medicine, rheumatology, obstetrics and gynecology, critical care medicine, and general surgery were randomly sampled from the American Medical Association (AMA) Physician Masterfile and completed the 10 minute online survey during January 14–28, 2010.
Excluding surgeons and OB/GYNs, 302 physicians (50 to 51 per specialty) had mean ages ranging from 45.6 to 49.1 years, and mean years of practice experience ranging from 14.5 to 19.1.
When provided with a hypothetical case report of an elderly female patient with recurrent epistaxis, nearly 90% of physicians in each of the surveyed specialties would have ordered a complete blood count (CBC) and coagulation studies (aPTT, PT, and INR) as part of their initial evaluation. Despite the resulting aPTT being abnormal at 42 seconds, other than hematologists, less than 1/2 would have chosen to repeat the studies. Fewer than 45% of surveyed physicians in all non-hematology specialties would have consulted a hematologist, with emergency medicine physicians least likely to consult (10%), and rheumatologists most likely to consult (43%).
Following the patient's second presentation several weeks later with bruising and abdominal/back pain, ≥ 90% of respondents would have ordered both a CBC and coagulation studies as part of their initial evaluation. When these results revealed a markedly changed aPTT of 63 seconds, the majority of respondents would not have repeated coagulation studies. Approximately 75% of internal medicine and geriatrics physicians would have consulted a hematologist at this point, versus 47% and 50%, respectively, in emergency medicine and critical care. Participants across specialties were clear in their preference for a CT scan of the abdomen (80%-84%).
Over a hypothetically additional 12 hours of observation, 73% to 94% of respondents would have consulted a hematologist at this point in the patient's clinical presentation, with laboratory studies revealing obvious ongoing blood loss and an aPTT that was at least twice the upper limits of normal; emergency medicine physicians remained least likely to consult. The majority of hematologists would have ordered 1:1 mixing studies with normal plasma to rule out coagulation inhibitors (97%). While approximately 80% or more of physicians in each specialty would have recommended hospital admission at the second presentation, the proportion recommending admission specifically to the ICU increased as the laboratory values deteriorated (worsening anemia and coagulopathy), most noticeably for the emergency medicine gatekeepers (35% to 73%).
Given the rarity and high morbidity and mortality of AH, physicians must harbor a high index of suspicion in order to promptly diagnose this condition in patients who present with recent-onset of acute bleeding. As exemplified by the findings of this survey, the determination of the etiology of an abnormal coagulation study should carry equal weight to looking for the site of bleeding, and could be facilitated by consultation with a hematologist. The insights from this survey highlight knowledge and practice gaps that could be the focus of targeted educational initiatives or outreach by hematologists and coagulation laboratories, including diagnostic algorithms and critical pathways to assure proper work-up of abnormal coagulation studies in patients who are not on anticoagulation.
Reding:Novo Nordisk Inc.: Consultancy. Cooper:Novo Nordisk Inc.: Employment.
Asterisk with author names denotes non-ASH members.