Micelle J. Haydel

Prediction of intracranial injury in children aged five years and older with loss of consciousness after minor head injury due to nontrivial mechanisms

STUDY OBJECTIVE Indications for computed tomography (CT) in children with minor head injury remain controversial. The objective of this preliminary study is to determine whether a clinical decision rule developed for adults could be used in children aged 5 years and older. METHODS A prospective questionnaire was completed on all patients who were aged 5 to 17 years with major mechanisms of injury resulting in minor head injury (defined as normal Glasgow Coma Scale or modified coma scale in infants, plus normal brief neurologic examination) and loss of consciousness. The questionnaire documented 6 clinical variables: headache, emesis, intoxication, seizure, short-term memory deficits, and physical evidence of trauma above the clavicles. CT was obtained for all patients, findings were compared with the results of the questionnaires, and the sensitivity and specificity of the decision rule were determined. RESULTS Throughout a 30-month period, 175 patients were enrolled, with a mean age of 12.8 years. Fourteen (8%) patients had intracranial injury or depressed skull fracture on CT. The presence of any of the 6 criteria was significantly associated with an abnormal CT scan result (P<.05) and was 100% (95% confidence interval 73% to 100%) sensitive for identifying patients with intracranial injury. CONCLUSION In this preliminary study, CT use in pediatric patients with minor head injury could have been safely reduced by 23% by using a clinical decision rule previously validated in adults.

In acute headache, the Ottawa Subarachnoid Hemorrhage rule had 100% sensitivity and 14% specificity

Question In patients presenting to the emergency department with acute headache, what is the accuracy of the Ottawa Subarachnoid Hemorrhage (SAH) rule for detecting SAH? Methods Design Prospective cohort study validating the Ottawa SAH rule. Setting 6 university-affiliated hospital emergency departments in Canada. Patients Treating physicians enrolled 1153 patients 16 years of age (mean age 44 y, 60% women) who had an acute, nontraumatic headache with peak intensity 1 hour after onset. Physicians missed an additional 590 eligible patients. Exclusion criteria included Glasgow Coma Scale score <15/15; headache onset >14 days before presentation; direct head trauma in the past 7 days; recurrent headache syndrome (3 similar recurrent headaches over >6 mo); referral from another hospital with confirmed SAH; previous assessment of the same headache with both computed tomography (CT) and lumbar puncture (LP); new focal neurologic deficits; papilledema; or previous SAH, cerebral aneurysm, brain neoplasm, ventricular shunt, or hydrocephalus. Description of prediction guide The Ottawa SAH rule indicates a need for further investigation for SAH if 1 of the following 6 factors are present: neck pain or stiffness, age >40 years, witnessed loss of consciousness, onset during exertion, thunderclap headache, or limited neck flexion. Outcomes Sensitivity, specificity, and likelihood ratios for detecting SAH. SAH (1 of visible subarachnoid blood on head CT; visible xanthochromia in cerebrospinal fluid [CSF]; or >1 x 106/L of erythrocytes in the final tube of CSF, with a visible aneurysm or arteriovenous malformation on cerebral angiography) was diagnosed at the index visit or at follow-up (1-mo or 6-mo telephone follow-up, medical record review, or coroner report) in patients discharged without normal CT and LP. Main results 87% of patients had a positive result with the Ottawa SAH rule and required further investigation. 87% of patients had a CT scan, 39% had an LP, and 5.8% were diagnosed with SAH. The accuracy of the Ottawa SAH rule for detecting SAH is shown in the Table. Conclusion In patients presenting to the emergency department with acute headache, the Ottawa Subarachnoid Hemorrhage rule had 100% sensitivity and 14% specificity for detecting subarachnoid hemorrhage. Diagnostic characteristics of the Ottawa Subarachnoid Hemorrhage rule for detecting subarachnoid hemorrhage* Sensitivity (95% CI) Specificity (CI) LR+ LR 100% (95 to 100) 14% (13 to 16) 1.16 0 *Abbreviations defined in Glossary. Commentary Clinical differentiation of SAH in the large pool of patients with benign causes of acute headache is challenging due to the lack of reliable clinical characteristics (1), while the current approach of CT followed by LP exposes these patients to radiation and painful invasive procedures. A recent study found that risk for aneurysmal SAH after a normal CT within 6 hours of headache onset was 0.4% (2). An ideal clinical decision rule (CDR) would identify all patients with SAH in whom neurosurgical interventions might improve outcomes and substantially reduce the number of unnecessary tests. Perry and colleagues validated such a CDR using a similar sample and setting as the original derivation study. The interobserver agreement was excellent (Cohen 0.82), suggesting that other users can expect to interpret the criteria as intended in the original study. Because the rule has not yet been prospectively externally validated, it is not known how it will perform in other settings, such as non-Canadian, rural, or nonacademic centers. However, extrapolating from the external validity of several other CDRs developed by the same research group at the same Canadian medical centers (3), the Ottawa SAH rule will probably be valid in other emergency departments in other countries. The high sensitivity of the Ottawa SAH rule obtained by Perry and colleagues is compelling, but the low specificity yields likelihood ratios with very limited clinical impact; diagnostic testing would have decreased by <5% if the clinical decision rule had been applied. At best, clinicians who strictly adhere to a CT/LP approach may find that the rule reduces the need for testing by about 15%, whereas clinicians who selectively use CT/LP may find that the rule actually increases the need for testing. Before routine application, a formal impact analysis of this CDR should be done, focusing on the absolute reduction in imaging and LP and separately grouping patients who present <6 hours after onset of acute headache. Because of the downstream effect of false-positive results or indeterminate workups, as well as identification of asymptomatic incidental aneurysm in patients with benign causes, future impact analyses should include a shared decision-making model with evidence-based, logical, patient-centered points on the clinical pathway.

Review: Adding anticholinergics to β2-agonists for asthma exacerbations reduces hospitalizations

Question In adolescents and adults who present to the emergency department (ED) with asthma exacerbations, does adding short-acting anticholinergics (SAACs) to short-acting 2-agonists (SABAs) reduce hospitalizations? Review scope Included studies compared SAACs plus SABAs (combination therapy) with SABAs alone in patients 16 years of age who presented to the ED with uncomplicated asthma exacerbations. Asthma had to have been diagnosed with international or national clinical criteria and/or spirometric assessment. Studies that included patients with chronic obstructive pulmonary disease (COPD) were included only if <20% of patients had COPD or if outcome data from patients with asthma could be extracted. Primary outcome was hospitalization; secondary outcomes included additional treatments required in the ED, relapse (return to ED with worsening symptoms after discharge), pulmonary function (FEV1), and adverse events. Review methods MEDLINE, EMBASE/Excerpta Medica, CINAHL, SCOPUS, LILACS, ProQuest Dissertations and Theses Global, Cochrane Database of Systematic Reviews, ACP Journal Club, Database of Abstracts of Reviews of Effects (DARE), Cochrane Central Register of Controlled Trials (Central), Cochrane Methodology Registry, Health Technology Assessment, NHS Economic Evaluation Database (all to Jul 2015); Cochrane Airways Group register of trials (Jul 2016); other databases and clinical trial registries; and recent emergency conference abstracts were searched for randomized controlled trials (RCTs) and prospective controlled clinical trials (CCTs). 23 RCTs (n =2724) met the selection criteria. SAACs assessed were ipratropium (19 trials), atropine (2 trials), and oxitropium (2 trials). SABAs assessed were salbutamol (19 trials), fenoterol (2 trials), levabuterol (1 trial), and metaproterenol (1 trials). 8 RCTs adequately described random sequence generation, 7 reported adequate allocation concealment, 7 described adequate blinding of patients and study personnel, and 6 reported adequate blinding of outcome assessors. Main results The main results are in the Table. Meta-analysis showed that, compared with SABAs, combination therapy improved FEV1 (mean difference [MD] 0.25 L, 95% CI 0.02 to 0.48) but not percent change in FEV1 (MD 21% predicted, CI 6 to 48). Conclusion In patients who present to the emergency department with asthma exacerbations, adding short-acting anticholinergics to short-acting 2-agonists reduces hospitalizations and relapses but increases adverse events. Short-acting anticholinergics (SAACs) plus short-acting 2-agonists (SABAs) vs SABAs alone in patients who present to the emergency department (ED) with asthma exacerbations* Outcomes Number of trials (n) Weighted event rates RRR (95% CI) NNT (CI) SAAC + SABA SABA alone Hospitalization 16 (2120) 17% 23% 28% (13 to 41) 17 (10 to 50) Additional treatments in ED 4 (543) 47% 55% 15% (13 to 36) Not significant Relapse 5 (1180) 21% 25% 20% (2 to 34) 24 (13 to 417) RRI (CI) NNH Adverse events 11 (1392) 19% 13% 46% (20 to 77) Unclear *Abbreviations defined in Glossary. RRR, RRI, NNT, and CI calculated from data in article using a random-effects model. Estimate for NNH is based on risk difference, which did not differ between groups (mean difference 0.06, CI 0.01 to 0.13) and had a high degree of heterogeneity (I2 =90%). Commentary SAACs have been used to treat asthma for many years despite having more adverse effects and being less effective than SABAs (1). Combined inhaled SABAs plus SAACs are synergistic in patients with asthma exacerbations (1). Current emergency textbooks recommend combined SAAC plus SABA therapy only in patients with severe asthma, but this approach has spread to patients with moderate and even mild exacerbations in the clinical setting (2). Several questions remain unanswered. Should SAACs plus SABAs be used routinely in all adult ED patients with acute asthma exacerbations? If not all, then in which subgroups? Does it matter which SAAC is used? Is 1 dose of a SAAC enough? Which SAAC has the fewest side effects? The systematic review and meta-analysis by Kirkland and colleagues found that SAACs plus SABAs reduced hospitalizations in patients with severe exacerbations (FEV1 or peak expiratory flow <50% predicted) but not in those with mild or moderate exacerbations. Hospitalizations were reduced regardless of which SAAC was used, but it was unclear whether single or multiple doses affected outcomes. The meta-analysis was not able to show which SAAC caused fewer adverse events, but the authors concluded that side effects were not major and were self-limited. The meta-analysis by Kirkland and colleagues supports the use of SAACs plus SABAs in ED patients with severe asthma exacerbations but not in patients with mild to moderate exacerbations. Future studies should focus on the effect of single vs multidose SAACs and the side effect profiles of common SAAC agents.

Review: Success of lumbar puncture is enhanced by reinserting the stylet before removing the needle

Source Citation Straus SE, Thorpe KE, Holroyd-Leduc J. How do I perform a lumbar puncture and analyze the results to diagnose bacterial meningitis? JAMA. 2006;296:2012-22. 17062865

Endocarditis diagnosed as multilobar, community acquired pneumonia

With the introduction of penicillin in the 1940s, the mortality rate from infective endocarditis (IE) decreased from 100% to about 30%.1 Despite newer antibiotics and other medical advances, the mortality rate remains 16% to 46%, and the annual incidence for the general population is 24 to 62 cases per million.2–11 Infective endocarditis has changed over the decades from a disease infecting rheumatic heart defects to an iatrogenic and self inflicted entity. With advances in invasive medical techniques and an increase in intravenous drug use, the prevalence of staphylococcus aureus has now surpassed streptococcus as the most common cause of IE.11–13 In addition, there is an increasing prevalence of resistant bacteria, poor compliance with treatment regimens, and risk of complications years later.8–10,14 The initial presentation to the emergency department (ED) is usually vague and non-specific, especially among intravenous drug users, and the number of missed diagnoses is unknown.15 The following case illustrates IE and its presentation and management. A 23 year old woman presented to the ED …