Meehan, Anne M.

Abstract Objectives In the general hospital wards, machine learning (ML)-based early warning systems (EWSs) can identify patients at risk of deterioration to facilitate rescue interventions. We assess subpopulation performance of a ML-based EWS on medical and surgical adult patients admitted to general hospital wards. Materials and Methods We assessed the scores of an EWS integrated into the electronic health record and calculated every 15 minutes to predict a composite adverse event (AE): all-cause mortality, transfer to intensive care, cardiac arrest, or rapid response team evaluation. The distributions of the First Score 3 hours after admission, the Highest Score at any time during the hospitalization, and the Last Score just before an AE or dismissal without an AE were calculated. The Last Score was used to calculate the area under the receiver operating characteristic curve (ROC-AUC) and the precision-recall curve (PRC-AUC). Results From August 23, 2021 to March 31, 2022, 35 937 medical admissions had 2173 (6.05%) AE compared to 25 214 surgical admissions with 4984 (19.77%) AE. Medical and surgical admissions had significant different (P <.001) distributions of the First Score, Highest Score, and Last Score among those with an AE and without an AE. The model performed better in the medical group when compared to the surgical group, ROC-AUC 0.869 versus 0.677, and RPC-AUC 0.988 versus 0.878, respectively. Discussion Heterogeneity of medical and surgical patients can significantly impact the performance of a ML-based EWS, changing the model validity and clinical discernment. Conclusions Characterization of the target patient subpopulations has clinical implications and should be considered when developing models to be used in general hospital wards.

The Deterioration Index (DI) is an automatic early warning system that utilizes a machine learning algorithm integrated into the electronic health record and was implemented to improve risk stratification of inpatients. Our pilot implementation showed superior diagnostic accuracy than standard care. A score >60 had a specificity of 88.5% and a sensitivity of 59.8% (PPV 0.1758, NPP 0.9817). However, acceptance in the clinical workflow was divided; nurses preferred standard care, while providers found it helpful.

Abstract Background We describe the clinical course of medical and surgical patients who received naloxone on general hospital wards for suspected opioid-induced respiratory depression (OIRD). Methods From May 2018 through October 2020, patients who received naloxone on hospital wards were identified and their records reviewed for incidence and clinical course. Results There were 86,030 medical and 106,807 surgical admissions. Naloxone was administered to 99 (incidence 11.5 [95% confidence interval 9.4–14.0] per 10,000 admissions) medical and 63 (5.9 [95% confidence interval 4.5–7.5]) surgical patients (P < 0.001). Median oral morphine equivalents administered within 24 hours before naloxone were 32 [15, 64] and 60 [32, 88] mg for medical and surgical patients, respectively (P = 0.002). The rapid response team was activated in 69 (69.7%) vs 42 (66.7%) and critical care transfers in 51 (51.5%) vs 30 (47.6%) medical and surgical patients respectively. The number of in-hospital deaths was 21 (21.2%) vs two (3.2%) and the number of discharges to hospice 12 (12.1%) vs one (1.6%) for medical and surgical patients, respectively (P = 0.001). Naloxone did not reverse OIRD in 38 (23%) patients, and these patients had more transfers to the intensive care unit and a higher 30-day mortality rate. Conclusion Medical inpatients are more likely to suffer OIRD than are surgical inpatients despite lower opioid doses. Definitive OIRD was confirmed in 77% of patients because of immediate naloxone response, whereas 23% of patients did not respond, and this subset was more likely to need a higher level of care and had a higher 30-day mortality rate. Careful monitoring of mental and respiratory variables is necessary when opiates are used in hospital.

ABSTRACT Target cell overexpression of the integrase binding domain (IBD) of LEDGF/p75 (LEDGF) inhibits HIV-1 replication. The mechanism and protein structure requirements for this dominant interference are unclear. More generally, how and when HIV-1 uncoating occurs postentry is poorly defined, and it is unknown whether integrase within the evolving viral core becomes accessible to cellular proteins prior to nuclear entry. We used LEDGF dominant interference to address the latter question while characterizing determinants of IBD antiviral activity. Fusions of green fluorescent protein (GFP) with multiple C-terminal segments of LEDGF inhibited HIV-1 replication substantially, but minimal chimeras of either polarity (GFP-IBD or IBD-GFP) were most effective. Combining GFP-IBD expression with LEDGF depletion was profoundly antiviral. CD4 + T cell lines were rendered virtually uninfectable, with single-cycle HIV-1 infectivity reduced 4 logs and high-input (multiplicity of infection = 5.0) replication completely blocked. We restricted GFP-IBD to specific intracellular locations and found that antiviral activity was preserved when the protein was confined to the cytoplasm or directed to the nuclear envelope. The life cycle block triggered by the cytoplasm-restricted protein manifested after nuclear entry, at the level of integration. We conclude that integrase within the viral core becomes accessible to host cell protein interaction in the cytoplasm. LEDGF dominant interference and depletion impair HIV-1 integration at distinct postentry stages. GFP-IBD may trigger premature or improper integrase oligomerization.

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) Gag and genomic RNA determinants required for encapsidation are well established, but where and when encapsidation occurs in the cell is unknown. We constructed MS2 phage coat protein labeling systems to track spatial dynamics of primate and nonprimate lentiviral genomic RNAs (HIV-1 and feline immunodeficiency virus [FIV]) vis-à-vis their Gag proteins in live cells. Genomic RNAs of both lentiviral genera were observed to traffic into the cytoplasm, and this was Rev dependent. In transit, FIV Gag and genomic RNA accumulated independently of each other at the nuclear envelope, and focal colocalizations of genomic RNA with an intact packaging signal (ψ) and Gag were observed to extend outward from the cytoplasmic face. In contrast, although HIV-1 genomic RNA was detected at the nuclear envelope, HIV-1 Gag was not. For both lentiviruses, genomic RNAs were seen at the plasma membrane if and only if Gag was present and ψ was intact. In addition, HIV-1 and FIV genomes accumulated with Gag in late endosomal foci, again, only ψ dependently. Thus, lentiviral genomic RNAs require specific Gag binding to accumulate at the plasma membrane, packaged genomes cointernalize with Gag into the endosomal pathway, and plasma membrane RNA incorporation by Gag does not trigger committed lentiviral particle egress from the cell. Based on the FIV results, we hypothesize that the Gag-genome association may initiate at the nuclear envelope.

Chromosomal integration enables human immunodeficiency virus (HIV) to establish a permanent reservoir that can be therapeutically suppressed but not eradicated. Participation of cellular proteins in this obligate replication step is poorly understood. We used intensified RNA interference and dominant-negative protein approaches to show that the cellular transcriptional coactivator lens epithelium–derived growth factor (LEDGF)/p75 (p75) is an essential HIV integration cofactor. The mechanism requires both linkages of a molecular tether that p75 forms between integrase and chromatin. Fractionally minute levels of endogenous p75 are sufficient to enable integration, showing that cellular factors that engage HIV after entry may elude identification in less intensive knockdowns. Perturbing the p75-integrase interaction may have therapeutic potential.