Acute chest syndrome is a dreaded, dangerous complication of sickle cell disease. Its pathophysiology is complex and poorly understood, but can include high pulmonary artery pressures and vasoconstriction of pulmonary arteries. Although microvascular occlusion by abnormal and viscous sickling blood occurs in the systemic circulation, it’s never been shown to occur in the lungs. Dessap [... read more]
Chronic thromboembolic pulmonary hypertension is a “new” condition (in terms of our recognition and understanding of it), whose true prevalence, natural history, and response to therapies continue to be elucidated. Meanwhile, specialized surgical centers continually make thromboendarterectomy safer, providing definitive cures that are nothing short of miraculous for those affected by this otherwise usually fatal [... read more]
More than 40 small, middling-quality studies (n~80, some randomized) showing inconsistent results as to whether antioxidant therapy with acetylcysteine or other drugs reduces the risk for contrast nephropathy / acute kidney injury after angiography or CT-angiography. A 2008 meta-analysis concluded Mucomyst was helpful, reducing risk of nephropathy by almost 40% vs saline alone. However, the authors noted [... read more]
Lucassen et al sharpened their pencils and tried to combine in a meta-analysis 52 studies (n=55,268) that examined the success of methods of using “gestalt” (subjective impression) or clinical decision rules (Wells, Geneva or revised Geneva scores) to diagnose acute pulmonary embolism. The punchline (and their unstated but implied conclusion) is, we just can’t safely [... read more]
The new coumadin-killers, direct thrombin inhibitor dabigatran (approved in the U.S.) and direct factor Xa inhibitor rivaroxaban (coming soon) could usher in an awesome new era of anticoagulation, without warfarin’s requirements of cumbersome monitoring and annoying in-hospital titrations. But what happens when patients taking these drugs bleed, or need emergency surgery? Fresh-frozen plasma doesn’t work. [... read more]
Increasing urine output should reduce the risk for contrast nephropathy, as should hustling contrast metal past vulnerable Na-K-Cl transporters using loop diuretics. However, furosemide alone increases the risk for contrast nephropathy. Some hypothesized that was due to diuretic-induced hypovolemia. Briguori et al report results of REMEDIAL-II. They randomized ~300 patients at very high risk for [... read more]
This month’s Current Opinion in Pulmonary Medicine has a section each on sarcoidosis, interstitial lung disease, and pulmonary vascular disease, mainly DVT/PE. Curr Opin Pulm Med 2011;17:297-402.
CT angiography is increasingly maligned for its overuse, its likely overdiagnosis of pulmonary emboli, and its radiation risk. The problem is, with >90% sensitivity and specificity, it’s just so damn good. And alternatives like V/Q, even when combined with clinical decision rules, haven’t been seen as providing sufficient accuracy. In a phase II clinical trial, [... read more]
September’s Current Opinion in Pulmonary Medicine has 4-5 review articles each on sarcoidosis (how to handle calcium problems; cardiac sarcoid); interstitial lung disease (biologics for connective-tissue disease related ILD; LAM therapies; stem cell therapy for pulmonary fibrosis), and pulmonary vascular disease. Curr Opin Pulm Med 2011;17.
Do we need to worry about pre-existing heparin-induced thrombocytopenia antibodies in people admitted with pulmonary embolism / deep venous thrombosis? Or can we keep happily slinging heparin at first sight? Warkentin et al analyze data from the Matisse VTE studies, which enrolled 3,994 patients with DVT or PE. All had ELISA HIT antibodies collected at [... read more]
Inactivity has not yet been shown to increase risk for VTE, until now. Among 69,000 women in the Nurses Health Study 1990-2008, the cohort that spent the most time sitting experienced twice as many pulmonary emboli as the cohort that spent the least time sitting, with a hazard ratio of 2.34 after mulitvariate analysis, report [... read more]
Update on Pulmonary Vascular Diseases 2010. Dweik RA, Erzurum SC. AJRCCM 2011;184:26-31.
Aujesky et al randomized 344 people in 19 European emergency departments with low-risk pulmonary embolism to either be sent home with enoxaparin and warfarin within one day, or to be treated until therapeutic on warfarin in-hospital. They were then treated for 90 days. One of 171 home-treated patients developed recurrent VTE, while none of the [... read more]
Boutitie et al analyzed pooled anticoagulation clinic data from 2,925 people with a first deep venous thrombosis or pulmonary embolism in the UK. They found that the recurrence risk after stopping anticoagulation at 3 months was equivalent to stopping at 6 months. Proximal DVTs were more likely to recur than distal DVTs. BMJ 2011;342:d3036. FREE [... read more]
Douma et al compared the Wells score, Geneva score, and the simplified versions of each, combined with D-dimer, on a prospective cohort of 807 patients with suspected PE (~23% of whom were found to have PE). With a negative D-dimer and a low-probability score using any rule, risk of pulmonary embolism was ~0.5%. However, only [... read more]
Salaun et al publish their experience using a simple algorithm for management of 321 consecutive patients with suspected pulmonary embolism at one center in France. The tool sought to avoid CT-angiography (and associated radiation) wherever possible, instead favoring leg ultrasounds and ventilation-perfusion scans. Only the indeterminate cases (a mere 35, or 11%) underwent CT-A. In [... read more]
Venous thromboembolism, long term management of: Bauer K, JAMA 2011;305:1336-1345.
Drospirenone is the new progesterone analog in heavily marketed new oral contraceptive pills (trade names Yaz, Yasmin, Angelique). Using a large insurance claims database, Jick et al identified 186 cases of DVT or PE in women aged 15-44 taking oral contraceptives and compared them to controls. Those taking drospirenone-containing OCPs had a nonfatal DVT/PE incidence [... read more]
DVT of the upper extremity: Kucher N, NEJM 2011;364:861-869.
Heparin-induced thrombocytopenia in the ICU. Sakr Y, Critical Care 2011;15:211.