Bottom line: In patients whose warfarin therapy is interrupted to undergo outpatient procedures, the risk of thromboembolism is low and the hemorrhagic risk of heparin bridging therapy is significant.
Citation: Garcia DA, Regan S, Henault LE, et al. Risk of thromboembolism with short-term interruption of warfarin therapy. Arch Intern Med. 2008;168(1):63-69.
Are Minor Injuries an Independent Risk Factor For Development of DVT?
Background: Prior studies focus on major injuries as a risk factor for deep-vein thrombosis (DVT) and PE. However, major injury is often associated with other risks for venous thrombosis, such as surgery, plaster casting, hospitalization, and extended bed rest. Risk of DVT with minor injuries that don’t lead to these factors is unknown.
Study design: Large population-based case-control study.
Setting: Six anticoagulation clinics in the Netherlands.
Synopsis: 2,471 consecutive cases (patients with first episode of DVT or PE) and 3,534 controls (partners of cases or random digit dialing contacts) were enrolled. Participants were mailed a questionnaire, including a list of eight common injuries.
Participants with history of cast, surgery, recent hospitalization, extended bed rest, or prior history of cancer were excluded. A subset of patients and controls underwent DNA and blood collection to evaluate for presence of a hypercoagulable state. Of the cases, 289 (11.7%) had a minor injury within three months of the index date, compared with 154 (4.4%) of controls, representing a threefold increased risk of DVT/PE with minor injury (OR 3.1). Partial ruptures of muscles or ligaments in the leg (OR 10.9), multiple simultaneous injuries (OR 9.9), and injury within four weeks of presentation (OR 4.0), were associated with increased risk of DVT/PE.
Patients found to be Factor V Leiden carriers with injury had an almost 50-fold increased risk of venous thromboembolism (VTE) compared with non-carriers without injury (OR 49.7). Authors appropriately address possible limitations, including recall and referral bias.
Bottom line: Minor leg injury is associated with threefold risk of DVT/PE, especially in the four weeks following injury. Providers should consider short-term prophylactic treatment in patients with Factor V Leiden or high-risk injuries.
Citation: Van Stralen KJ, Rosendaal FR, Doggen CJ. Minor injuries as a risk factor for venous thrombosis. Arch Intern Med. 2008;168(1):21-26.
Is Oral Amox-Clav Non-inferior to IV Antibiotics in Pediatric Pyelonephritis?
Background: Present guidelines recommend initial treatment for pediatric pyelonephritis to be a parenteral third-generation cephalosporin followed by oral antibiotics. One prior randomly selected controlled trial compared oral antibiotics only with antibiotics started parenterally, but there was a higher-than-usual incidence of vesicoureteral reflux and female gender in the study.
Study design: Non-inferiority, multicenter, random, open label, controlled trial.
Setting: Twenty-eight pediatric units in northeast Italy from 2000-2005
Synopsis: 502 children age 1 month to less than 7 years with a clinical diagnosis of first occurrence of acute pyelonephritis according to urinalysis and urine culture (requiring two concordant consecutive tests) with at least two of the following conditions: fever of 38 degrees C or more or elevated erythrocyte sedimentation rate (ESR) or c-reactive protein (CRP), and elevated neutrophil count were randomized to receive oral amoxicillin-clavulanate (AC) or parenteral ceftriaxone followed by oral AC. Exclusion criteria were sepsis, dehydration, vomiting, and creatinine clearance of 70 ml/min or less.
Also, 400 children had dimercaptosuccinic acid (DMSA) scintigraphy within 10 days of study entry. Meantime, 223 had repeat DMSA at one year, and 177 had normal scans at study entry so were not repeated. At one year, 20% of patients were lost to follow-up. The primary outcome was renal scarring at one year. Secondary outcomes included time to fever defervescence, reduction in inflammatory indices, and percentage with sterile urine after 72 hours. Intention to treat analysis showed no significant differences between oral (n=244) and parenteral (n=258) treatment, both in the primary outcome 13.7% vs. 17.7% (95% CI, -11.1% to 3.1%), and secondary outcomes.