208 Abstracts

differences in patient outcomes would help in justifying or pro-viding evidence against measures such as those proposed byCMS for head CT scans.

, IMPACT OF THROMBOLYSIS ON STROKE OUT-COME AT 12 MONTHS IN A POPULATION. Fischer U,Mono ML, Zwahlen M, et al. Stroke 2012;43:1039–45.

Multiple clinical trials have shown that thrombolytics im-prove short-term outcomes in individuals with acute ischemicstroke (AIS). Several similar studies show that thrombolyticsalso improve long-term outcomes. What is not clear, and whatthis article attempted to address, is whether these findings canbe replicated in a single study population. Investigators prospec-tively assessed 807 patients with first-time AIS whowere admit-ted to the hospital within 48 h of symptom onset in Bern,Switzerland over the course of 12 months. Of the 807 total pa-tients, 13% (n = 107) received thrombolysis. Thirty-eight per-cent of patients (n = 41) received intra-arterial thrombolysis,33% (n = 35) received intravenous thrombolysis, and 5% (n =5) underwent mechanical thrombolysis. Median National Insti-tute of Health Stroke Scale (NIHSS) at admission was 14 in thegroup that received thrombolytics (n = 107) and 4.3 in the groupthat did not receive thrombolytics (n = 700). Follow-up was thenobtained at 3 and 12 months to assess for predictors of mortalityas well as favorable outcomes. Favorable outcomes were de-fined as a modified Rankin Scale # 2. The authors found thatthe following variables were independent predictors of mortal-ity at 3 months and 12 months: age $ 75 years, higher NIHSS,and higher Charlson comorbidity index. They found that the fol-lowing variables were independent predictors of favorable out-comes at 3 and 12 months: age < 75 years, male gender, NIHSS< 4, lower Charlson comorbidity index, and thrombolysis. Theauthors emphasize that thrombolysis is the only modifiable vari-able that was shown to predict favorable outcomes at 3 months(relative risk [RR] 1.49; 95% confidence interval [CI] 1.18–1.89) and 12 months (RR 1.59; 95% CI 1.24–2.04).

[Mike Miller, MD

Denver Health Medical Center, Denver, CO]

Comments: Although numerous clinical trials have shownthat thrombolytics improve outcomes in AIS, this is the firstpopulation-based study to do so. Although this is unlikely to sig-nificantly change the clinical practice of most physicians, it doesprovide one with more confidence when discussing the pros andcons of thrombolysis at the bedside.

, SLEEP APNEA AND RISK OF DEEP VEIN THROM-BOSIS: A NON-RANDOMIZED, PAIR-MATCHED CO-HORT STUDY. Chou KT, Huang CC, Chen YM, et al. Am JMed 2012;125:374–80.

Sleep apnea is defined as apneic episodes during the sleepinghours, which may be due to either obstruction or temporary lossof central neurologic drive. The majority of patients with sleepapnea (90%) have obstructive sleep apnea (OSA). A growingbody of research supports the association betweenOSA and a hy-percoaguable state. This study from Taiwan sought to evaluatethe association between OSA and deep vein thrombosis (DVT).The study was a nonrandomized pair-matched cohort model us-ing the National Health Insurance Research Database in Taiwan

to identify 5680 new diagnoses of DVT and their pair-matchedcontrols between 2000 and 2007. Mean follow-up was 3.56 62.12 years. The primary outcome was new diagnosis of DVT.The secondary outcome was use of continuous positive airwaypressure (CPAP) devices as a proxy measure of OSA severityand its association with increased risk ofDVT. The authors founda significantly higher incidence of DVT development in patientswith sleep apnea when compared to controls (hazard ratio [HR]3.113, p < 0.002). The only other demographic factors of signif-icance were female sex (HR 2.145, p < 0.017) and hypertension(HR 2.510, p < 0.034). In the subset of patients with OSAwhoused CPAP, there was significantly higher risk of DVT (HR9.575, p < 0.001 vs. HR 2.751, p < 0.007; respectively). The au-thors’ final conclusionwas that sleep apnea is an independent riskfactor for future development of DVT. They also posited that, ifuse of CPAP can be used as a proxy for worse disease, increasingseverity of OSA increases risk of DVT formation.

[Peter Emiley, MD,Denver Health Medical Center, Denver, CO]

Comments: This study provides some interesting informa-tion on the association between OSA and the development ofDVT. Clearly, causality cannot be established by such an obser-vational design, and confounders such as obesity and underlyingmedical disease were not controlled for. Nonetheless, it wouldbewise for Emergency Physicians to bewary of DVT in patientswith OSAwho present with the appropriate clinical symptoms.

, RISK OF FEBRILE SEIZURES AND EPILEPSY AF-TER VACCINATION WITH DIPHTHERIA, TETANUS,ACELLULAR PERTUSSIS, INACTIVATED POLIOVI-RUS, AND HAEMOPHILUS INFLUENZAE TYPE B.Sun Y, Christensen J, Hviid A, Li J, Vedsted P, Olsen J,Vestergaard M. JAMA 2012;307:823–31.

Prior studies have demonstrated an increased risk of febrileseizures with whole-cell pertussis vaccine, but no studies todate have clearly demonstrated a significant increase in febrileseizures with an acellular pertussis vaccine. In this large cohortstudy from Denmark, 378,834 children were followed after 3,5, and 12-month vaccinations with an acellular-pertussis-con-taining combinationvaccine. Outcomemeasures included febrileseizures within 7 days of receiving the vaccine as well as rates ofepilepsy diagnosis. Children outside the 7-day timewindowwereused as controls. Over a 5-year time period, 7811 children underthe age of 18 months were diagnosed with febrile seizures. Ofthese children, 17 were diagnosed within the first 7 days afterthe first vaccine, 32 children after the second vaccine, and 201children after the third vaccine. Calculated hazard ratios (HR)of febrile seizures within the first week after each vaccinationwere not statistically significant. The risk of seizure on the firstday after each vaccination, however, was increased after the 3-month vaccine (3-month vaccineHR 6.02, 95% confidence inter-val [CI] 2.86–12.65) and after the 5-month vaccine (HR 3.94,95% CI 2.18–7.10), but not after the 12-month vaccine (HR1.07, 95%CI 0.73–1.57). Patients were followed for 7 years aftervaccination to monitor for the rate of epilepsy. There were 2117children diagnosed with epilepsy, with 813 occurring between 3and 15 months. When compared to children not vaccinated, vac-cinated children had a lower risk of epilepsy between 3 and 15