Comparing Intubation Rates in Patients Receiving Parenteral Olanzapine With and Without a Parenteral Benzodiazepine in the Emergency Department.

STUDY OBJECTIVE: United States prescribing information recommends against coadministration of injectable olanzapine with injectable benzodiazepines due to a risk of cardiorespiratory depression, whereas European prescribing information recommends the 2 drugs not be administered within 60 minutes of each other. In contrast, a recently published American College of Emergency Physicians clinical policy recommends injectable olanzapine and benzodiazepines be coadministered for treating severe agitation. We sought to compare injectable olanzapine with and without injectable benzodiazepines for evidence of cardiorespiratory depression. METHODS: We performed a retrospective study of patients in an urban emergency department from January 2017 through November 2019 who received parenteral olanzapine with or without parenteral benzodiazepines. We included patients receiving 2 total medication doses, either olanzapine+benzodiazepine or 2 doses of olanzapine, coadministered within 60 minutes. The primary outcome was tracheal intubation in the emergency department. Secondary outcomes included hypotension (systolic blood pressure less than 90 mmHg) and hypoxemia (SpO2 less than 90%). RESULTS: We identified 693 patients (median [alcohol]=210 mg/dL, median age=37 years [IQR 29 to 49]). In total, 549 received 2 doses of olanzapine, and 144 patients received olanzapine and a benzodiazepine. We found no difference in intubation rates between the olanzapine-only group (21/549, 3.8%) and the olanzapine+benzodiazepine group (5/144, 3.5%; difference=0.3%, 95% confidence interval -3.0% to 3.7%). Rates of hypoxemia (2% olanzapine-only and 3% olanzapine+benzodiazepine) and hypotension (9% both groups) also were not different between groups. CONCLUSION: We found no difference in cardiorespiratory depression between patients receiving only olanzapine versus olanzapine plus a benzodiazepine.

Massive Sodium Nitrite Overdose: A Case for Prehospital Methylene Blue.

Sodium nitrite overdose leads to profound methemoglobinemia and may quickly progress to death. It is an increasingly common method of suicide and is often fatal. Methylene blue is an effective but time-sensitive antidote that has the potential to save lives when administered early. In this case report, we describe a fatal sodium nitrite overdose and the subsequent creation of a prehospital protocol for our large urban Emergency Medical Services system.

Toxic Tetrahydrocannabinol (THC) Dose in Pediatric Cannabis Edible Ingestions.

OBJECTIVE: The study characterizes cannabis toxicity in relation to tetrahydrocannabinol (THC) dose in pediatric edible cannabis ingestions. METHODS: This is a retrospective review of children aged <6 years presenting with edible cannabis ingestions of known THC dose within a pediatric hospital network (January 1, 2015-October 25, 2022). Cannabis toxicity was characterized as severe if patients exhibited severe cardiovascular (bradycardia, tachycardia/hypotension requiring vasopressors or intravenous fluids, other dysrhythmias), respiratory (respiratory failure, apnea, requiring oxygen supplementation), or neurologic (seizure, myoclonus, unresponsiveness, responsiveness to painful stimulation only, requiring intubation or sedation) effects. Cannabis toxicity was characterized as prolonged if patients required >6 hours to reach baseline. The relationship between THC dose and severe and prolonged toxicity was explored using multivariable logistic regression and receiver operator characteristic curve analyses. RESULTS: Eighty patients met inclusion. The median age was 2.9 years. The median THC ingestion was 2.1 mg/kg. Severe and prolonged toxicity was present in 46% and 74%, respectively. THC dose was a significant predictor of severe (adjusted odds ratio 2.9, 95% confidence interval: 1.8-4.7) and prolonged toxicity (adjusted odds ratio 3.2, 95% confidence interval: 1.6-6.5), whereas age and sex were not. Area under the curve was 92.9% for severe and 87.3% for prolonged toxicity. THC ingestions of ≥1.7 mg/kg can predict severe (sensitivity 97.3%) and prolonged toxicity (sensitivity 75.4%). CONCLUSIONS: The THC dose of edible cannabis correlates to the degree of toxicity in children <6 years old. The threshold of 1.7 mg/kg of THC may guide medical management and preventive regulations.

Cognitive activity relates to cognitive performance but not to Alzheimer disease biomarkers.

OBJECTIVE: We aimed to determine whether there was a relationship between lifestyle factors and Alzheimer disease biomarkers. METHODS: In a cross-sectional study, we evaluated self-reported histories of recent and past cognitive activity, self-reported history of recent physical activity, and objective recent walking activity in 186 clinically normal individuals with mean age of 74 ± 6 years. Using backward elimination general linear models, we tested the hypotheses that greater cognitive or physical activity would be associated with lower Pittsburgh compound B-PET retention, greater (18)F-fluorodeoxyglucose-PET metabolism, and larger hippocampal volume, as well as better cognitive performance on neuropsychological testing. RESULTS: Linear regression demonstrated that history of greater cognitive activity was correlated with greater estimated IQ and education, as well as better neuropsychological testing performance. Self-reported recent physical activity was related to objective exercise monitoring. However, contrary to hypotheses, we did not find evidence of an association of Pittsburgh compound B retention, (18)F-fluorodeoxyglucose uptake, or hippocampal volume with past or current levels of cognitive activity, or with current physical activity. CONCLUSIONS: We conclude that a history of lifelong cognitive activity may support better cognitive performance by a mechanism that is independent of brain ß-amyloid burden, brain glucose metabolism, or hippocampal volume.

Regional fluorodeoxyglucose metabolism and instrumental activities of daily living across the Alzheimer's disease spectrum.

BACKGROUND: Impairment in instrumental activities of daily living (IADL) begins as individuals with amnestic mild cognitive impairment (MCI) transition to Alzheimer's disease (AD) dementia. IADL impairment in AD dementia has been associated with inferior parietal, inferior temporal, and superior occipital hypometabolism using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). OBJECTIVE: To investigate the relationship between regional FDG metabolism and IADL in clinically normal (CN) elderly, MCI, and mild AD dementia subjects cross-sectionally and longitudinally. METHODS: One hundred and four CN, 203 MCI, and 95 AD dementia subjects from the Alzheimer's Disease Neuroimaging Initiative underwent clinical assessments every 6 to 12 months for up to three years and baseline FDG PET. The subjective, informant-based Functional Activities Questionnaire was used to assess IADL. General linear models and mixed effects models were used, covarying for demographics, cognition, and behavior. RESULTS: The cross-sectional analysis revealed middle frontal and orbitofrontal hypometabolism were significantly associated with greater IADL impairment. Additionally, the interaction of diagnosis with posterior cingulate and with parahippocampal hypometabolism showed a greater decline in IADL performance as metabolism decreased for the AD dementia relative to the MCI group, and the MCI group relative to the CN group. The longitudinal analysis showed that baseline middle frontal and posterior cingulate hypometabolism were significantly associated with greater rate of increase in IADL impairment over time. CONCLUSION: These results suggest that regional synaptic dysfunction, including the Alzheimer-typical medial parietal and less typical frontal regions, relates to daily functioning decline at baseline and over time across the early AD spectrum.

Apathy is associated with increased amyloid burden in mild cognitive impairment.

Apathy is the most common neuropsychiatric symptom in mild cognitive impairment (MCI) and Alzheimer's disease (AD) dementia. The authors sought to determine whether apathy is associated with cortical amyloid burden, as measured by Pittsburgh Compound B (PiB) positron emission tomography (PET), and regional hypometabolism, measured by 18F-fluorodeoxyglocuse (FDG) PET in MCI. The authors found a significant association between increased apathy (lower Apathy Evaluation Scale score) and greater cortical PiB retention independent of age, but no significant association between apathy and regional FDG metabolism. These results suggest that increased apathy is associated with greater amyloid burden but not regional hypometabolism in MCI.

Subjective cognitive complaints and amyloid burden in cognitively normal older individuals.

Accumulating evidence suggests that subjective cognitive complaints (SCC) may indicate subtle cognitive decline characteristic of individuals with preclinical Alzheimer's disease (AD). In this study, we sought to build upon previous studies by associating SCC and amyloid-ß deposition using positron emission tomography with Pittsburgh Compound B (PiB-PET) in cognitively normal older individuals. One-hundred thirty one subjects (mean age 73.5±6) were administered three subjective cognitive questionnaires and a brief neuropsychological battery. A relationship between a subjective memory complaints composite score and cortical PiB binding was found to be significant, even after controlling for depressive symptoms. By contrast, there were no significant relationships between objective cognitive measures of memory and executive functions and cortical PiB binding. Our study suggests that SCC may be an early indicator of AD pathology detectable prior to significant objective impairment.

Free-ranging little brown myotis (Myotis lucifugus) heal from wing damage associated with white-nose syndrome.

White-nose syndrome (WNS) is having an unprecedented impact on hibernating bat populations in the eastern United States. While most studies have focused on widespread mortality observed at winter hibernacula, few have examined the consequences of wing damage that has been observed among those bats that survive hibernation. Given that WNS-related wing damage may lead to life-threatening changes in wing function, we tested the hypothesis that reduced abundance of free-ranging little brown myotis (Myotis lucifugus) with severe wing damage as the summer progresses is due to healing of wing tissue. Photographs of captured and recaptured adult females were examined for wing damage and healing rates were calculated for each category of wing damage index (WDI = 0-3). We found that free-ranging bats with severe wing damage were able to heal to a lower WDI score within 2 weeks. Bats with the most severe wing damage had faster healing rates than did individuals with less damage. We also found a significant relationship between body condition and WDI for adult females captured in the early weeks of the active season. Our results support the hypothesis that some bats can heal from severe wing damage during the active season, and thus may not experience increased mortality associated with reduced functions of wings. We urge researchers and wildlife managers to use caution when interpreting data on WDI to assess the impact of WNS on bat populations, especially during the later months of the active season.