Higher modified frailty index score is associated with 30-day postoperative complications following simultaneous bilateral total knee arthroplasty.

BACKGROUND: There is no clear consensus regarding patient populations at highest risk for complications from simultaneous bilateral total knee arthroplasty (TKA). The purpose of this study was to determine whether the comorbidities comprising the modified Frailty Index (mFI) were correlated with poor outcomes following simultaneous bilateral TKA. METHODS: From 2006 to 2019, patients undergoing bilateral TKA aged 50 years or older were identified in a national database. The 5-item mFI was calculated based on the presence of five comorbidities: diabetes, congestive heart failure, hypertension, chronic obstructive pulmonary disease, and dependent functional status. Chi-squared and multivariable regression analyses were used to evaluate the association of mFI scores with postoperative complications. RESULTS: The study analyzed 8,776 patients with an average age of 65 years. After adjustment on multivariable regression analysis, compared to patients with a mFI score of 0, those with a score of 1 had an increased risk of pulmonary complication (OR 3.14; p = 0.011), renal problem (OR 12.86; p = 0.022), sepsis complication (OR 2.82; p = 0.024), postoperative transfusion (OR 1.19; p = 0.012), and non-home discharge (OR 1.17; p = 0.002).Patients with a score of 2 compared to 0 had similar complications when compared. These patients had an increased risk of cardiac complication (OR 4.84; p = 0.009) and prolonged hospital stay (OR 4.06; p < 0.001). CONCLUSION: Increased mFI scores were associated with significantly higher complication rates in patients undergoing simultaneous bilateral TKA compared to unilateral TKA. Our results can be used to identify which patients may need a staged bilateral TKA or preoperative optimization to safely undergo a simultaneous bilateral TKA. LEVEL OF EVIDENCE: III.

Decreasing Incidence of Partial Meniscectomy, and Increasing Incidence of Meniscus Preservation Surgery from 2010-2020 in the United States.

PURPOSE: The aim of the present study was to characterize the incidence of meniscus surgery from 2010 to 2020 in the United States, using the metrics of age, sex, type of meniscus surgery, and Charlson Comorbidity Index (CCI). METHODS: A retrospective analysis was performed using the PearlDiver national insurance claims database from 2010-2020. Meniscus surgeries were identified using Current Procedural Terminology codes. Patients were stratified by procedure type, age, biological sex, and Charlson Comorbidity Index (CCI) scores. Compound annual growth rate (CAGR) analysis and analysis of variance (ANOVA) were performed to analyze the trends and demographic variables between cohorts. RESULTS: Of 2,053,884 meniscus surgeries, 94.7% were meniscectomies, 0.3% were open repairs, 4.9% were arthroscopic repairs, and 0.1% were meniscal transplantations. CAGR analysis displayed a 4.0% decrease per year in total meniscus surgery. For individual procedure types, the largest decrease was in meniscectomy, and the largest increase was in open repair. Patients undergoing meniscal transplantation were youngest, with the lowest CCI. Meniscectomy patients were oldest, and open repair patients had the highest average CCI. Most procedures were performed on female patients (52.4%), and patients in the 50-59-year age group (30.4%). CONCLUSIONS: There was a sustained decrease in the incidence of total meniscus surgeries from 2010-2020. Meniscectomy was the procedure with the highest incidence, however, it showed the most significant decline in usage over the study period. Conversely, meniscal repair and transplantation procedures increased during the study period.

Engineered deletions of HIV replicate conditionally to reduce disease in nonhuman primates.

Antiviral therapies with reduced frequencies of administration and high barriers to resistance remain a major goal. For HIV, theories have proposed that viral-deletion variants, which conditionally replicate with a basic reproductive ratio [R0] > 1 (termed "therapeutic interfering particles" or "TIPs"), could parasitize wild-type virus to constitute single-administration, escape-resistant antiviral therapies. We report the engineering of a TIP that, in rhesus macaques, reduces viremia of a highly pathogenic model of HIV by >3log10 following a single intravenous injection. Animal lifespan was significantly extended, TIPs conditionally replicated and were continually detected for >6 months, and sequencing data showed no evidence of viral escape. A single TIP injection also suppressed virus replication in humanized mice and cells from persons living with HIV. These data provide proof of concept for a potential new class of single-administration antiviral therapies.

Cognitive Performance Between Latino and White Non-Latino Individuals With Parkinson's Disease.

OBJECTIVE: Cognitive impairment is a common nonmotor symptom in Parkinson's disease (PD). Individuals of Latino background are traditionally underrepresented in research on PD. Despite the fact that Latinos comprise 18% of the U.S. population, they commonly make up less than 5% of samples in studies of PD. Emerging evidence suggests that Latino individuals with PD may experience disparities relative to White non-Latinos in terms of having more severe motor symptoms, more severe depressive symptoms, and worse health-related quality of life. The purpose of the present study was to investigate differences in cognitive performance between Latino and White non-Latino individuals with PD and examine correlates of cognitive performance. METHODS: Data were obtained from the Parkinson's Progression Markers Initiative. Participants included 60 Latino individuals with PD and 1,009 White non-Latino individuals with PD, all of whom were followed annually for up to 5 years. Participants completed neuropsychological tests of attention and working memory, processing speed, visuospatial functioning, verbal fluency, and immediate and delayed memory and recall. RESULTS: Relative to White non-Latino individuals with PD, Latino individuals with PD had significantly lower scores on the global measure of cognitive functioning, a test of processing speed, and tests of working memory and attention. Years of education was the strongest correlate of performance in these three cognitive domains among individuals in the Latino group. CONCLUSIONS: These findings provide initial evidence of disparities in cognitive functioning among Latino individuals with PD. Educational disadvantages may be one potential driver of these disparities.

HIV transcription persists in the brain of virally suppressed people with HIV.

HIV persistence in the brain is a barrier to cure, and potentially contributes to HIV-associated neurocognitive disorders. Whether HIV transcription persists in the brain despite viral suppression with antiretroviral therapy (ART) and is subject to the same blocks to transcription seen in other tissues and blood, is unclear. Here, we quantified the level of HIV transcripts in frontal cortex tissue from virally suppressed or non-virally suppressed people with HIV (PWH). HIV transcriptional profiling of frontal cortex brain tissue (and PBMCs where available) from virally suppressed (n = 11) and non-virally suppressed PWH (n = 13) was performed using digital polymerase chain reaction assays (dPCR). CD68+ myeloid cells or CD3+ T cells expressing HIV p24 protein present in frontal cortex tissue was detected using multiplex immunofluorescence imaging. Frontal cortex brain tissue from PWH had HIV TAR (n = 23/24) and Long-LTR (n = 20/24) transcripts. Completion of HIV transcription was evident in brain tissue from 12/13 non-virally suppressed PWH and from 5/11 virally suppressed PWH, with HIV p24+CD68+ cells detected in these individuals. While a block to proximal elongation was present in frontal cortex tissue from both PWH groups, this block was more extensive in virally suppressed PWH. These findings suggest that the brain is a transcriptionally active HIV reservoir in a subset of virally suppressed PWH.

Quantitative-MRI analysis of the effects of retrograde nailing on vascularity of the distal femur: A cadaveric study.

BACKGROUND: Distal femur fractures remain treatment challenges with a considerable postoperative non-union rate. Concern remains that surgery may compromise osseous vascularity. This study aimed to determine effects of retrograde femoral intramedullary nailing (RFIN) on distal femur vascularity, and the locations of the middle genicular artery terminal branches in relation to the standard RFIN entry point. METHODS: Five lower limb cadaveric pairs were obtained (ten specimens). Experimental limbs were randomly assigned, and contralateral limbs served as controls. An 11 mm femoral nail was implanted in experimental specimens. Controls only underwent a medial parapatellar incision with capsulotomy. Quantitative pre- and post-contrast-MRI was performed to assess arterial contributions to distal femur regions. Osseous vascularity was further evaluated with contrast-CT imaging. Next, specimens were injected with latex medium, and dissection was performed to assess extraosseous vasculature. RESULTS: No statistically significant differences were found with quantitative-MRI in experimental and control groups for the entire distal femur or individual regions. The experimental group demonstrated a small mean decrease of 1.4% in distal femur arterial contributions. CT and anatomic dissection confirmed maintenance of middle genicular artery terminal branches. On average, 3.3 (±1.3) terminal branches entered along the posterior intercondylar notch. A mean distance of 15.2 mm (±6.9 mm) was found between the posterior RFIN entry point and these terminal branches. CONCLUSIONS: RFIN did not significantly alter arterial contributions to the distal femur or disrupt the middle genicular artery terminal branches. However, care must be taken to ensure nail entry point accuracy given proximity of the entry point to terminal branches.

The positive reinforcing effects of cocaine and opposite-sex social contact: roles of biological sex and estrus.

RATIONALE: Preclinical studies report that drug use and social contact mutually influence the reinforcing effects of one another. Most of these studies have used same-sex dyads exclusively, and the role of factors related to biological sex and hormonal fluctuations are not well understood. OBJECTIVES: The purpose of this study was to examine the reinforcing effects of cocaine and social contact with an opposite-sex partner in male and female rats, and how these effects are modulated by ovarian hormones. METHODS: Male and female rats were trained in a nonexclusive choice procedure in which cocaine and social contact with an opposite-sex partner were simultaneously available on concurrent progressive ratio schedules of reinforcement. To examine the effects of ovarian hormones related to estrous cycling, Experiment 1 used naturally cycling, gonadally intact females, whereas Experiment 2 used ovariectomized females, and estrus was artificially induced with exogenous hormones. RESULTS: In both experiments, cocaine and social contact functioned as robust reinforcers, and there were no significant effects of biological sex or estrus status of the females. The positive reinforcing effects of both cocaine and social contact increased as a function of cocaine dose, indicating that contingent cocaine administration increases the reinforcing effects of social contact. CONCLUSIONS: These data suggest that cocaine use among opposite-sex partners may enhance factors that contribute to social bonding.

Benchmarking and integrating human B-cell receptor genomic and antibody proteomic profiling.

Immunoglobulins (Ig), which exist either as B-cell receptors (BCR) on the surface of B cells or as antibodies when secreted, play a key role in the recognition and response to antigenic threats. The capability to jointly characterize the BCR and antibody repertoire is crucial for understanding human adaptive immunity. From peripheral blood, bulk BCR sequencing (bulkBCR-seq) currently provides the highest sampling depth, single-cell BCR sequencing (scBCR-seq) allows for paired chain characterization, and antibody peptide sequencing by tandem mass spectrometry (Ab-seq) provides information on the composition of secreted antibodies in the serum. Yet, it has not been benchmarked to what extent the datasets generated by these three technologies overlap and complement each other. To address this question, we isolated peripheral blood B cells from healthy human donors and sequenced BCRs at bulk and single-cell levels, in addition to utilizing publicly available sequencing data. Integrated analysis was performed on these datasets, resolved by replicates and across individuals. Simultaneously, serum antibodies were isolated, digested with multiple proteases, and analyzed with Ab-seq. Systems immunology analysis showed high concordance in repertoire features between bulk and scBCR-seq within individuals, especially when replicates were utilized. In addition, Ab-seq identified clonotype-specific peptides using both bulk and scBCR-seq library references, demonstrating the feasibility of combining scBCR-seq and Ab-seq for reconstructing paired-chain Ig sequences from the serum antibody repertoire. Collectively, our work serves as a proof-of-principle for combining bulk sequencing, single-cell sequencing, and mass spectrometry as complementary methods towards capturing humoral immunity in its entirety.

Neurodevelopmental implications of COVID-19-induced gut microbiome dysbiosis in pregnant women.

The global public health emergency of COVID-19 in January 2020 prompted a surge in research focusing on the pathogenesis and clinical manifestations of the virus. While numerous reports have been published on the acute effects of COVID-19 infection, the review explores the multifaceted long-term implications of COVID-19, with a particular focus on severe maternal COVID-19 infection, gut microbiome dysbiosis, and neurodevelopmental disorders in offspring. Severe COVID-19 infection has been associated with heightened immune system activation and gastrointestinal symptoms. Severe COVID-19 may also result in gut microbiome dysbiosis and a compromised intestinal mucosal barrier, often referred to as 'leaky gut'. Increased gut permeability facilitates the passage of inflammatory cytokines, originating from the inflamed intestinal mucosa and gut, into the bloodstream, thereby influencing fetal development during pregnancy and potentially elevating the risk of neurodevelopmental disorders such as autism and schizophrenia. The current review discusses the role of cytokine signaling molecules, microglia, and synaptic pruning, highlighting their potential involvement in the pathogenesis of neurodevelopmental disorders following maternal COVID-19 infection. Additionally, this review addresses the potential of probiotic interventions to mitigate gut dysbiosis and inflammatory responses associated with COVID-19, offering avenues for future research in optimizing maternal and fetal health outcomes.

Altered spike IgG Fc N-linked glycans are associated with hyperinflammatory state in adult COVID and Multisystem Inflammatory Syndrome in Children.

Background: Severe COVID and multisystem inflammatory syndrome (MIS-C) are characterized by excessive inflammatory cytokines/chemokines. In adults, disease severity is associated with SARS-CoV-2-specific IgG Fc afucosylation, which induces pro-inflammatory cytokine secretion from innate immune cells. This study aimed to define spike IgG Fc glycosylation following SARS-CoV-2 infection in adults and children and following SARS-CoV-2 vaccination in adults and the relationships between glycan modifications and cytokine/chemokine levels. Methods: We analyzed longitudinal (n=146) and cross-sectional (n=49) serum/plasma samples from adult and pediatric COVID patients, MIS-C patients, adult vaccinees, and adult and pediatric healthy controls. We developed methods for characterizing bulk and spike IgG Fc glycosylation by capillary electrophoresis (CE) and measured levels of ten inflammatory cytokines/chemokines by multiplexed ELISA. Results: Spike IgG were more afucosylated than bulk IgG during acute adult COVID and MIS-C. We observed an opposite trend following vaccination, but it was not significant. Spike IgG were more galactosylated and sialylated and less bisected than bulk IgG during adult COVID, with similar trends observed during pediatric COVID/MIS-C and following SARS-CoV-2 vaccination. Spike IgG glycosylation changed with time following adult COVID or vaccination. Afucosylated spike IgG exhibited inverse and positive correlations with inflammatory markers in MIS-C and following vaccination, respectively; galactosylated and sialylated spike IgG inversely correlated with pro-inflammatory cytokines in adult COVID and MIS-C; and bisected spike IgG positively correlated with inflammatory cytokines/chemokines in multiple groups. Conclusions: We identified previously undescribed relationships between spike IgG glycan modifications and inflammatory cytokines/chemokines that expand our understanding of IgG glycosylation changes that may impact COVID and MIS-C immunopathology.

HcGr76 responds to fructose and chlorogenic acid and is involved in regulation of peptide expression in the midgut of Hyphantria cunea larvae.

BACKGROUND: Sensing dietary components in the gut is important to ensure an appropriate hormonal response and metabolic regulation after food intake. The fall webworm, Hyphantria cunea, is a major invasive pest in China and has led to significant economic losses and ecosystem disruption. The larvae's broad host range and voracious appetite for leaves make H. cunea a primary cause of serious damage to both forests and crops. To date, however, the gustatory receptors (Grs) of H. cunea and their regulatory function remain largely unknown. RESULTS: We identified the fall webworm gustatory receptor HcGr76 as a fructose and chlorogenic acid receptor using Ca2+ imaging and determination of intracellular Ca2+ concentration by a microplate reader. Moreover, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis revealed that HcGr76 is highly expressed in the anterior and middle midgut. Knockdown of HcGr76 caused a significant reduction in the expression of neuropeptide F 1 (NPF1) and CCHamide-2, and led to a decrease in carbohydrate and lipid levels in the hemolymph. CONCLUSION: Our studies provide circumstantial evidence that HcGr76 expressed in the midgut is involved in sensing dietary components, and regulates the expression of relevant peptide hormones to alter metabolism in H. cunea larvae, thus providing a promising molecular target for the development of new insect-specific control products. © 2024 Society of Chemical Industry.

Ground-Based Pyrethroid Adulticides Reduce Mosquitoes But Not Nontarget Insects in Central Florida.

As stewards of public and environmental health, mosquito control agencies are rightfully concerned about impacts on nontarget organisms. This study examined the impact of a modern, pyrethroid based ground adulticide program using ultra-low volume applications in a metropolitan county in central Florida. Nontarget insects and mosquitoes were collected in a before-after control-impact design at 21 sites over 1.5 years. While mosquitoes were reduced, we found no evidence for reduction of nontarget insects, regardless of taxon. Night-flying Lepidoptera may experience greater risk than other nontarget taxa, but overall effects of adulticide missions on this group were low and inconsistent. Instead, meteorology, habitat, and phenology dominate patterns of nontarget abundance. Mosquito reduction was more clearly observed and corrected post-mission reduction was consistent with results expected in complex urban and suburban treatment zones.

Swift regulation of nicotinic acetylcholine receptors (nAChRs) and glutathione S-transferase (GST) enables the rapid detoxification of thiacloprid in pine sawyer beetles.

Thiacloprid, a neonicotinoid insecticide, has become one of the major control agents for the pine sawyer beetle, Monochamus alternatus Hope, however, the mechanism of detoxification is unknown. We demonstrate that glutathione S-transferases (GSTs) and nicotinic acetylcholine receptors (nAChRs) are involved in the rapid detoxification of thiacloprid in M. alternatus larvae. The activity of detoxification enzyme GSTs was significantly higher, while the activity of acetylcholinesterase (AChE) was inhibited under thiacloprid exposure. The inhibition of AChE activity led to lethal over-stimulation of the cholinergic synapse, which was then released by the rapid downregulation of nAChRs. Meanwhile, GSTs were overexpressed to detoxify thiacloprid accordingly. A total of 3 nAChR and 12 GST genes were identified from M. alternatus, among which ManAChRα2 and MaGSTs1 were predicted to confer thiacloprid tolerance. RNA interference (RNAi) was subsequently conducted to confirm the function of ManAChRα2 and MaGSTs1 genes in thiacloprid detoxification. The successful knock-down of the ManAChRα2 gene led to lower mortality of M. alternatus under LC30 thiacloprid treatment, and the suppression of the MaGSTs1 gene increased the mortality rate of M. alternatus. However, the mortality rate has no significant difference with controls when thiacloprid was fed together with both dsMaGSTs1 and dsManAChRα2. Molecular docking modeled the molecular basis for interaction between MaGSTs1/ManAChR and thiacloprid. This study highlights the important roles that ManAChRα2 and MaGSTs1 genes play in thiacloprid detoxification through transcriptional regulation and enzymatic metabolization, and proposes a new avenue for integrated pest management that combines pesticides and RNAi technology as an efficient strategy for M. alternatus control.

Capturing the catalytic intermediates of parkin ubiquitination.

Parkin is an E3 ubiquitin ligase implicated in early-onset forms of Parkinson's disease. It catalyzes a transthiolation reaction by accepting ubiquitin (Ub) from an E2 conjugating enzyme, forming a short-lived thioester intermediate, and transfers Ub to mitochondrial membrane substrates to signal mitophagy. A major impediment to the development of Parkinsonism therapeutics is the lack of structural and mechanistic detail for the essential, short-lived transthiolation intermediate. It is not known how Ub is recognized by the catalytic Rcat domain in parkin that enables Ub transfer from an E2~Ub conjugate to the catalytic site and the structure of the transthiolation complex is undetermined. Here, we capture the catalytic intermediate for the Rcat domain of parkin in complex with ubiquitin (Rcat-Ub) and determine its structure using NMR-based chemical shift perturbation experiments. We show that a previously unidentified α-helical region near the Rcat domain is unmasked as a recognition motif for Ub and guides the C-terminus of Ub toward the parkin catalytic site. Further, we apply a combination of guided AlphaFold modeling, chemical cross-linking, and single turnover assays to establish and validate a model of full-length parkin in complex with UbcH7, its donor Ub, and phosphoubiquitin, trapped in the process of transthiolation. Identification of this catalytic intermediate and orientation of Ub with respect to the Rcat domain provides important structural insights into Ub transfer by this E3 ligase and explains how the previously enigmatic Parkinson's pathogenic mutation T415N alters parkin activity.

Response to von Schmalensee et al.

Von Schmalensee et al. present two concerns about our study. While the first stems from a general disagreement about our simulation methodology, the second is a useful observation of a modelling choice we made that affected simulation outcomes, but in ways that do not invalidate our original conclusions.

Prior fragility fractures are associated with a higher risk of 8-year complications following total shoulder arthroplasty.

Patients who sustain fragility fractures prior to total shoulder arthroplasty have significantly higher risk for bone health-related complications within 8 years of procedure. Identification of these high-risk patients with an emphasis on preoperative, intraoperative, and postoperative bone health optimization may help minimize these preventable complications. PURPOSE: As the population ages, more patients with osteoporosis are undergoing total shoulder arthroplasty (TSA), including those who have sustained a prior fragility fracture. Sustaining a fragility fracture before TSA has been associated with increased risk of short-term revision rates, periprosthetic fracture (PPF), and secondary fragility fractures but long-term implant survivorship in this patient population is unknown. Therefore, the purpose of this study was to characterize the association of prior fragility fractures with 8-year risks of revision TSA, periprosthetic fracture, and secondary fragility fracture. METHODS: Patients aged 50 years and older who underwent TSA were identified in a large national database. Patients were stratified based on whether they sustained a fragility fracture within 3 years prior to TSA. Patients who had a prior fragility fracture (7631) were matched 1:1 to patients who did not based on age, gender, Charlson Comorbidity Index (CCI), smoking, obesity, diabetes mellitus, and alcohol use. Kaplan-Meier and Cox Proportional Hazards analyses were used to observe the cumulative incidences of all-cause revision, periprosthetic fracture, and secondary fragility fracture within 8 years of index surgery. RESULTS: The 8-year cumulative incidence of revision TSA (5.7% vs. 4.1%), periprosthetic fracture (3.8% vs. 1.4%), and secondary fragility fracture (46.5% vs. 10.1%) were significantly higher for those who had a prior fragility fracture when compared to those who did not. On multivariable analysis, a prior fragility fracture was associated with higher risks of revision (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.24-1.74; p < 0.001), periprosthetic fracture (HR, 2.98; 95% CI, 2.18-4.07; p < 0.001) and secondary fragility fracture (HR, 8.39; 95% CI, 7.62-9.24; p < 0.001). CONCLUSIONS: Prior fragility fracture was a significant risk factor for revision, periprosthetic fracture, and secondary fragility fracture within 8 years of primary TSA. Identification of these high-risk patients with an emphasis on preoperative and postoperative bone health optimization may help minimize these complications. LEVEL OF EVIDENCE: III.

Gastrointestinal Stromal Tumour of the Appendix: A Very Rare Entity.

A 74-year-old man who presented with upper abdominal pain was found to have an incidental appendiceal mass on cross-sectional imaging. He underwent a laparoscopic appendicectomy with histopathological examination confirming a completely resected appendiceal gastrointestinal stromal tumour (GIST). Appendiceal GISTs are rare. Therefore, there is limited evidence to guide risk stratification and management with extrapolation of prognosis from data on GISTs at other sites. This paper highlights the rarity of these tumours and presents another case which correlates well with the existing but limited literature. There is a need to maintain a registry of this rare disease entity with the maintenance of longer-term follow-up data.

Breaking Binaries: The Critical Need for Feminist Bioethics in Pediatric Gender-Affirming Care.

This commentary responds to Moti Gorin's article "What Is the Aim of Pediatric 'Gender-Affirming' Care?" We argue that Gorin's case against pediatric gender-affirming care rests upon numerous false conceptual binaries: female/male, public/private, objective/subjective, and medically necessary/elective. Drawing on feminist bioethics, we show how such dichotomous thinking is both inaccurate and marginalizing of gender minorities.

CENsible: Interpretable Insights into Small-Molecule Binding with Context Explanation Networks.

We present a novel and interpretable approach for assessing small-molecule binding using context explanation networks. Given the specific structure of a protein/ligand complex, our CENsible scoring function uses a deep convolutional neural network to predict the contributions of precalculated terms to the overall binding affinity. We show that CENsible can effectively distinguish active vs inactive compounds for many systems. Its primary benefit over related machine-learning scoring functions, however, is that it retains interpretability, allowing researchers to identify the contribution of each precalculated term to the final affinity prediction, with implications for subsequent lead optimization.

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.