The LIMIT clinical decision instrument reduces neuroimaging compared to unstructured clinician judgement in recurrent seizures.

INTRODUCTION: Given the many causes of seizures, emergency physicians often utilize brain computed tomography (CT) to evaluate for intracranial pathology. Previously, we have validated the LIMIT (Let's Image Malignancy, Intracranial Hemorrhage, and Trauma) clinical decision instrument (CDI) study to determine which patients with recurrent seizures require emergent neuroimaging. The LIMIT CDI had a negative predictive value (NPV) of 99.9%. Here, we seek to compare the LIMIT CDI to unstructured physician judgement. METHODS: This was an observational study of patients who presented with a complaint of seizure. A research assistant reviewed the electronic medical record (EMR) for each patient and applied the LIMIT CDI. Brain CT was used as a proxy for physician judgement. If no brain CT was ordered and the patient was discharged from the emergency department (ED), the EMR was searched to determine whether patient had any medical visits within one year of the index visit. If the patient had no new neurological findings on follow up or abnormalities on follow up neuroimaging, this was considered a patient who did not require a brain CT in the ED. Patients who did not have a CT on their ED visit and had no follow up visits were excluded. RESULTS: 1739 patients were screened and 1108 patients were in the final analysis. 24 patients who did not have a brain CT and no follow up visits were excluded. 10 patients (0.9%) had positive CTs. 9/10 of the patients were identified by the CDI resulting in a sensitivity of 90%, specificity of 81.1% and a negative predictive value (NPV) of 99.9%, and a negative likelihood ratio (LR) of 0.12. Clinician judgement identified all 10 patients with a positive brain CT for a sensitivity of 100%, specificity of 67.8%, and a NPV and negative LR of 100% and 0, respectively. Using unstructured clinical judgement, EPs ordered 364 brain CTs while only 217 brain CTs would have been ordered using the CDI, a reduction of 13.3%. DISCUSSION: When compared to unstructured physician judgement, the LIMIT CDI would have reduced brain CT usage by more than 13%. Although the LIMIT CDI needs to be validated in a larger set of patients, it performed better than unstructured physician judgement for evaluating need for emergent neuroimaging after recurrent seizures.

Derivation of a clinical decision instrument to identify patients with status epilepticus who require emergent brain CT.

BACKGROUND: Studies have shown the value of CT brain imaging in adults with first-time seizures, but there are no recommendations regarding emergent brain CTs in persons with an established seizure disorders. Our study aimed to derive a clinical decision instrument (CDI) to determine which patients with status epilepticus (SE) require emergent brain imaging. METHODS: This was a retrospective chart review of patients who presented to our emergency department with SE between 2010 and 2018. Patients with first-time seizures were excluded. A priori, we defined high risk criteria for emergent imaging as well as positive findings on brain CT. High risk criteria included known malignancy, trauma, and immunosuppression. Positive CT scans included findings such as intracranial hemorrhage (ICH) and mass. RESULTS: We identified 214 patients who met inclusion criteria Of the 181 patients without high risk criteria, 3% had positive CT scans. Of the 33 patients with high risk criteria, 10% had positive CT scans. The sensitivity, specificity, PPV, and NPV for our initial CDI were 38%, 85%, 9%, and 97%. Adding the criterion of prior ICH would have lowered our miss rate to 0.6%. Modifying our CDI to 1) History of ICH, 2) Malignancy, 3) Immunosuppression, and 4) Trauma would result in a CDI with sensitivity, specificity, PPV, and NPV of 87.5%, 87.4%, 21.2%, and 99.5%. CONCLUSIONS: By using four criteria to identify high risk patients, we can defer CT scanning in the vast majority of patients with SE and known seizure disorders. This CDI should be prospectively validated before adoption.

Males Receive Low-Tidal Volume Component of Lung Protective Ventilation More Frequently than Females in the Emergency Department.

INTRODUCTION: Mechanical ventilation is a commonly performed procedure in the emergency department (ED). Approximately 240,000 patients per year receive mechanical ventilation in the ED representing 0.23% of ED visits. An ED-based trial published in 2017 showed that a bundle of interventions in mechanically ventilated patients, including low tidal volume ventilation, reduced the development of acute respiratory distress syndrome by nearly 50%. Prior literature has shown that as many as 40% of ED patients do not receive lung protective ventilation. Our goal was to determine whether differences exist between the percent of males vs females who are ventilated at ≥ 8 milliliters per kilogram (mL/kg) of predicted body weight. METHODS: We conducted this study at Temple University Hospital, a tertiary care center located in Philadelphia, Pennsylvania. This was a planned subgroup analysis of study looking at interventions to improve adherence to recommended tidal volume settings. We used a convenience sample of mechanically ventilated patients in our ED between September 1, 2017, and September 30, 2018. All adult patient > 18 years old were eligible for inclusion in the study. Our primary outcome measure was the number of patients who had initial tidal volumes set at > 8 mL/kg of predicted body weight. Our secondary outcome was the number of patients who had tidal volumes set at ≥ 8 mL/kg at 60 minutes after initiation of mechanical ventilation. RESULTS: A total of 130 patients were included in the final analysis. We found that significantly more females were initially ventilated with tidal volumes ≥ 8 mL/kg compared to men: 56% of females vs 9% of males (p=<0.001). Data was available for 107 patients (82%) who were in the ED at 60 minutes after initiation of mechanical ventilation. Again, a significantly larger percentage of females were ventilated with tidal volumes ≥ 8 mL/kg at 60 minutes: 56% of females vs 10% of males (p<0.001). CONCLUSION: The vast majority of tidal volumes ≥ 8 mL/kg during mechanical ventilation occurs in females. We suggest that objective measurements, such as a tape measure and tidal volume card, be used when setting tidal volumes for all patients, especially females.