Hospital Medicine Experts Discuss Ineffectual Treatment of Blood Clots with IV Heparin

This case involves a female patient admitted to the hospital with a history of swelling and pain of the right leg and shortness of breath. She was a non-smoker, had a history of hypertension, and a strong family history of clotting disorder. An ER work-up with ultrasound of the her leg led to the diagnosis of a deep vein thrombosis. In addition, a CT scan showed a pulmonary embolus. The remaining work-up indicated the patient was otherwise stable. The patient was started on standard IV heparin therapy and transferred to the ICU. Despite the fact the patient was non-responsive on standard doses of heparin, and the fact she continued to complain of shortness of breath, the patient was transferred to a general medical floor. No further imaging studies were performed after the initial studies in the ER. Shortly after she was transferred to the general floor, the patient coded after just after complaining of increasing shortness of breath, and her cause of death was identified as pulmonary embolism.

Question(s) For Expert Witness

1. What could have been done for the patient in this case to avoid such an outcome?

2. Given the patient's symptoms, history, and resistance to standard heparin therapy, what alternative treatment could have been used?

3. Given the brief case summary, should the patient have been transferred out of the ICU?

4. What mechanisms could have been in place to mitigate any further damage from additional pulmonary emboli?

Expert Witness Response E-007034

As a hospitalist I routinely see patients with venous thromboembolism including many patients requiring initial ICU care, including patients with obesity. Avoidance of this outcome is not always possible but the three obvious options in this case are:a) better monitoring b) an IVC filter given the large existing PE and remaining DVT threatening PE and c) a non-heparin anticoagulant.

Symptoms and history do not necessarily indicate anticoagulant inappropriateness - since severe PE can happen with any treatment, many PE patients lack a provocation. This circumstance is fairly common given the unpredictability of heparin, perhaps compounded by weight, and its management depends on the details. If she was mildly sub therapeutic, switching to another product like LMWH may actually have been a smart strategy, because antithrombin deficiency is quite rare, most providers have never seen it, and simple problems with heparin drips are common. If she was suspiciously unsuccessful with the heparin drip then this could have been recognized as a clue for antithrombin deficiency. Pharmacy or hematology consultation may have been appropriate in either case. If evidence of an unusual course was sufficient, then the patient could have been switched to an alternative agent like argatroban or rivaroxaban. Her main treatment options before death were IVC filter placement and thrombolysis. IVCF use in this situation is of marginal benefit (no mortality reduction overall immediately or after years; a tradeoff between PE and DVT), but relatively common and has a physiologic rationale--in this case, a patient who likely could not have tolerated another PE. Thrombolysis was recently found to have a favorable risk-benefit profile in a meta-analysis, which found reduced death compared with bleeding risks, in the setting of intermediate risk pulmonary emboli. Its use has not become standard of care, however, because of some issues with the study. However, given the reported decline in the patient's status, reconsideration of therapy should have occurred. Thrombolysis as a rescue strategy is the obvious and well known back up plan to up front anticoagulation.