External validation of the Ottawa subarachnoid hemorrhage clinical decision rule in patients with acute headache ☆

We aim to externally validate the Ottawa subarachnoid hemorrhage (OSAH) clinical decision rule. This rule identifies patients with acute nontraumatic headache who require further investigation. We conducted a medical record review of all patients presenting to the emergency department (ED) with headache from January 2011 to November 2013. Per the OSAH rule, patients with any of the following predictors require further investigation: age 40 years or older, neck pain, stiffness or limited flexion, loss of consciousness, onset during exertion, or thunderclap. The rule was applied following the OSAH rule criteria. Patients were followed up for repeat visits within 7 days of initial presentation. Data were electronically harvested from the electronic medical record and manually abstracted from individual patient charts using a standardized data abstraction form. Calibration between trained reviewers was performed periodically. A total of 5034 ED visits with acute headache were reviewed for eligibility. There were 1521 visits that met exclusion criteria, and 3059 had headache of gradual onset or time to maximal intensity greater than or equal to 1 hour. The rule was applied to 454 patients (9.0%). There were 9 cases of subarachnoid hemorrhage (SAH), yielding an incidence of 2.0% (95% confidence interval [CI], 1.0%-3.9%) in the eligible cohort. The sensitivity for SAH was 100% (95% CI, 62.9%-100%); specificity, 7.6% (95% CI, 5.4%-10.6%); positive predictive value, 2.1% (95% CI 1.0%-4.2%); and negative predictive value, 100% (95% CI, 87.4%-100%). The OSAH rule was 100% sensitive for SAH in the eligible cohort. However, its low specificity and applicability to only a minority of ED patients with headache (9%) reduce its potential impact on practice

Derivation and Validation of a New Equation for Estimating Free Valproate Concentration in Critically Ill Adult Patients

IMPORTANCE:. Protein binding of valproate varies among ICU patients, altering the biologically active free valproate concentration (VPAC). Free VPAC is measured at few laboratories and is often discordant with total VPAC. Existing equations to predict free VPAC are either not validated or are inaccurate in ICU patients. OBJECTIVES:. We designed this study to derive and validate a novel equation to predict free VPAC using data from ICU patients and to compare its performance to published equations. DESIGN:. Retrospective cohort study. SETTING:. Two academic medical centers. PARTICIPANTS:. Patients older than 18 years old with concomitant free and total VPACs measured in the ICU were included in the derivation cohort if admitted from 2014 to 2018, and the validation cohort if admitted from 2019 to 2022. MAIN OUTCOMES AND MEASURES:. Multivariable linear regression was used to derive an equation to predict free VPAC. Modified Bland-Altman plots and the rate of therapeutic concordance between the measured and predicted free VPAC were compared. RESULTS:. Demographics, median free and total VPACs, and valproate free fractions were similar among 115 patients in the derivation cohort and 147 patients in the validation cohort. The Bland-Altman plots showed the new equation performed better (bias, 0.3 [95% limits of agreement, –13.6 to 14.2]) than the Nasreddine (–9.2 [–26.5 to 8.2]), Kodama (–9.7 [–30.0 to 10.7]), Conde Giner (–7.9 [–24.9 to 9.1]), and Parent (–9.9 [–30.7 to 11.0]) equations, and similar to Doré (–2.0 [–16.0 to 11.9]). The Doré and new equations had the highest therapeutic concordance rate (73%). CONCLUSIONS AND RELEVANCE:. For patients at risk of altered protein binding such as ICU patients, existing equations to predict free VPAC are discordant with measured free VPAC. A new equation had low bias but was imprecise. External validation should be performed to improve its precision and generalizability. Until then, monitoring free valproate is recommended during critical illness

Impact of Atrial Fibrillation on Outcomes in Patients Hospitalized With Nontraumatic Intracerebral Hemorrhage

Objective: To assess the effect of atrial fibrillation (AF) on outcomes in hospitalizations for non-traumatic intracerebral hemorrhage (ICH). Patients and Methods: We queried the National Inpatient Sample database between January 1, 2016, and December 31, 2019, to identify hospitalizations with an index diagnosis of non-traumatic ICH using ICD-10 code I61. The cohort was divided into patients with and without AF. Propensity score matching was used to balance the covariates between AF and non-AF groups. Logistic regression was used to analyze the association. All statistical analyses were performed using weighted values. Results: Our cohort included 292,725 hospitalizations with a primary discharge diagnosis of non-traumatic ICH. From this group, 59,005 (20%) recorded a concurrent diagnosis of AF, and 46% of these patients with AF were taking anticoagulants. Patients with AF reported a higher Elixhauser comorbidity index (19.8±6.0 vs 16.6±6.4; P<.001) before propensity matching. After propensity matching, the multivariate analysis reported that AF (aOR, 2.34; 95% CI, 2.26-2.42; P<.001) and anticoagulation drug use (aOR, 1.32; 95% CI, 1.28-1.37; P<.001) were independently associated with all-cause in-hospital mortality. Moreover, AF was significantly associated with respiratory failure requiring mechanical ventilation (odds ratio, 1.57; 95% CI, 1.52-1.62; P<.001) and acute heart failure (odds ratio, 1.26; 95% CI, 1.19-1.33; P<.001) compared with the absence of AF. Conclusion: These data suggest that non-traumatic ICH hospitalizations with coexistent AF are associated with worse in-hospital outcomes such as higher mortality and acute heart failure