Clinical impact of rapid influenza PCR in the adult emergency department on patient management, ED length of stay, and nosocomial infection rate

Clinical impact of rapid molecular diagnostic tests in patients presenting with viral respiratory symptoms: A systematic literature review

BACKGROUND

Molecular tests can detect lower concentrations of viral genetic material over a longer period of respiratory infection than antigen tests. Delays associated with central laboratory testing can result in hospital-acquired transmission, avoidable patient admission, and unnecessary use of antimicrobials, all which may lead to increased cost of patient management. The aim of this study was to summarize comparisons of clinical outcomes associated with rapid molecular diagnostic tests (RMDTs) versus other diagnostic tests for viral respiratory infections.

METHODS

A systematic literature review (SLR) conducted in April 2023 identified studies evaluating clinical outcomes of molecular and antigen diagnostic tests for patients suspected of having respiratory viral infections.

RESULTS

The SLR included 21 studies, of which seven and 14 compared RMDTs (conducted at points of care or at laboratories) to standard (non-rapid) molecular tests or antigen tests to detect SARS-CoV-2 and influenza, respectively. In studies testing for SARS-CoV-2, RMDTs led to reductions in time to test results versus standard molecular tests (range of the reported medians: 0.2-3.8 hours versus 4.3-35.9 hours), with similar length of emergency department stay (3.2-8 hours versus 3.7-28.8 hours). Similarly, in studies testing for influenza, RMDTs led to reductions in time to test results versus standard molecular tests (1-3.5 hours versus 18.2-29.2 hours), with similar length of emergency department stay (3.7-11 hours versus 3.8-11.9 hours). RMDTs were found to decrease exposure time of uninfected patients, rate of hospitalization, length of stay at the hospitals, and frequency of unnecessary antiviral and antibacterial therapy, while improving patient flow, compared to other tests.

CONCLUSIONS

Compared to other diagnostic tests, RMDTs improve clinical outcomes, test turnaround time, and stewardship by decreasing unnecessary use of antibiotics and antivirals. They also reduce hospital admission and length of stay, which may, in turn, reduce unnecessary exposure of patients to hospital-acquired infections and their associated costs.

Effects of Different SARS-CoV-2 Testing Strategies in the Emergency Department on Length of Stay and Clinical Outcomes: A Randomised Controlled Trial

The turn-around-time (TAT) of diagnostic and screening measures such as testing for SARS-CoV-2 can affect a patient's length of stay (LOS) in the hospital as well as the emergency department (ED). This, in turn, can affect clinical outcomes. Therefore, a reliable and time-efficient SARS-CoV-2 testing strategy is necessary, especially in the ED. In this randomised controlled trial, n = 598 ED patients presenting to one of three university hospital EDs in Berlin, Germany, and needing hospitalisation were randomly assigned to two intervention groups and one control group. Accordingly, different SARS-CoV-2 testing strategies were implemented: rapid antigen and point-of-care (POC) reverse transcription polymerase chain reaction (rtPCR) testing with the Roche cobas® Liat® (LIAT) (group one n = 198), POC rtPCR testing with the LIAT (group two n = 197), and central laboratory rtPCR testing (group three, control group n = 203). The median LOS in the hospital as an inpatient across the groups was 7 days. Patients' LOS in the ED of more than seven hours did not differ significantly, and furthermore, no significant differences were observed regarding clinical outcomes such as intensive care unit stay or death. The rapid and POC test strategies had a significantly (p < 0.01) shorter median TAT (group one 00:48 h, group two 00:21 h) than the regular central laboratory rtPCR test (group three 06:26 h). However, fast SARS-CoV-2 testing strategies did not reduce ED or inpatient LOS significantly in less urgent ED admissions. Testing strategies should be adjusted to the current circumstances including crowding, SARS-CoV-2 incidences, and patient cohort. This trial is registered with DRKS00023117.

Nosocomial influenza in a pediatric general ward: Effects of isolation and cohort placement of children with influenza

OBJECTIVE

Many studies have described nosocomial outbreaks of influenza in specialized wards. We evaluated nosocomial transmission of influenza in a pediatric general ward.

DESIGN

Retrospective observational study.

SETTING

Single secondary hospital.

PATIENTS

The study included 814 hospitalized children with influenza between September 2015 and August 2020.

METHODS

The medical records of the included children were retrospectively reviewed, and clinical characteristics of children with community-acquired (CA) influenza and hospital-acquired (HA) influenza were determined. The room of each included child during hospitalization was traced to identify the children exposed to them.

RESULTS

CA influenza and HA influenza were diagnosed in 789 (96.9%) and 25 (3.1%) children, respectively. Among children with CA influenza, 691 (87.6%) were isolated or place in a cohort on admission. In total, 98 children (12.4%) admitted to multibed rooms exposed 307 children with noninfluenza diseases to influenza during 772 patient days; 3 exposed children (1.0%) were diagnosed with HA influenza. Including these 3 children, 25 children (19 without definite in-hospital exposure to influenza and 3 exposed to other children with HA influenza) were diagnosed with HA influenza, and 11 (44.0%) exposed 31 children with noninfluenza diseases to influenza for 85 patient days. Also, 3 exposed children (9.7%) were diagnosed with HA influenza, a significantly higher rate than that for CA influenza (P = .005). The clinical characteristics were comparable between children with HA influenza and those with CA influenza.

CONCLUSIONS

Cohort placement of children with influenza in a pediatric general ward can be effective in controlling nosocomial transmission of influenza. However, control measures for children with HA influenza should be emphasized.

Antimicrobial prescribing after rapid influenza PCR implementation in the emergency department

INTRO

Influenza shares common symptoms with bacterial pneumonia, which may result in unnecessary antibiotic prescriptions in the emergency department (ED) when the diagnosis is unknown. Rapid influenza polymerase chain reaction (PCR) tests have reduced turnaround times compared to standard multiplex PCR respiratory panels allowing for earlier diagnosis, which may improve antimicrobial stewardship outcomes in the ED. This study aims to compare antibiotic and antiviral use before and after deployment of the rapid influenza PCR in the ED.

METHODS

This single-center, retrospective, cohort study included pediatric and adult patients discharged from the ED with a positive influenza test using a standard multiplex PCR respiratory panel (January 2017 - July 2019) or rapid PCR (July 2019 - February 2020). The primary endpoint was number of antibiotic prescriptions pre- and post-implementation of the rapid influenza PCR in the ED. Secondary endpoints included number of antiviral prescriptions, duration of antimicrobial therapy, test turnaround time, ED length of stay, 30-day readmission, and adverse events. A multivariable logistic regression evaluated patient factors associated with antimicrobial prescribing.

RESULTS

A total of 620 positive influenza results were identified with 280 patients (standard multiplex PCR = 33; rapid PCR = 247) meeting inclusion criteria. Patients were less likely to be prescribed antibiotics (39.4% vs 8.9%, OR 0.15, 95% CI 0.067-0.34) and more likely to be prescribed antivirals (24.2% vs 61.1%, OR 4.92, 95% CI 2.13-11.34) with the rapid influenza PCR. Rapid influenza PCR significantly reduced ED length of stay (4.9 vs 3.4 h, p < 0.01) and test turnaround time (27 h vs 3.5 h, p < 0.01). Patients at high risk for complications associated with influenza were more likely to be prescribed antiviral therapy (22.7% vs 67.8%, OR 7.16, 95% CI 2.52-20.40). Based on the regression analysis conducted, asthma, (OR 3.5, 95% CI 1.48-8.26), immunosuppression (OR 9.6, 95% CI 1.18-78.2), and age <5 years old (OR 3.1, 95% CI 1.80-5.45) were predictors of antiviral prescribing.

CONCLUSION

Implementation of a rapid influenza PCR in the ED reduced antibiotic use and optimized antiviral therapy for patients with influenza including those at higher risk of complications.

Impact of Fast SARS-CoV-2 Molecular Point-Of-Care Testing on Patients' Length of Stay in an Emergency Department

The ID NOW COVID-19 system (IDNOW) is a point-of-care test (POCT) providing results within 15 min. We evaluated the impact of IDNOW use on patient length of stay (LOS) in an emergency department (ED). In the ED of Saint-Louis Hospital, Paris, France, adult patients requiring a rapid diagnosis of SARS-CoV-2 were tested with Cepheid Xpert Xpress SARS-CoV-2 or FilmArray respiratory panel RP2 in the virology laboratory between 18 October and 3 November 2020 (period 1) and with IDNOW between 4 November and 30 November 2020 (period 2). A total of 676 patients participated in the study, 337 during period 1 and 339 during period 2. The median LOS in ED was significantly higher in period 1 than in period 2 (276 versus 208 min, P < 0.0001). More patients spent less than 4 h in the ED in period 2 (61.3%) than in period 1 (38.3%) (P < 0.0001). By univariate analysis, factors associated with ED LOS were hypertension, anosmia/ageusia, number of patients per day, and ID NOW implementation in period 2. By multivariate analysis, the period of testing remained significantly associated with ED LOS. Rapid molecular SARS-CoV-2 POCT was associated with a reduced LOS for patients admitted to an ED.

IMPORTANCE During COVID-19 pandemic upsurges, emergency departments had to deal with a massive flow of incoming patients. The need for COVID-19 infection status determination before medical ward admission worsened ED overcrowding. The development of molecular point-of-care testing gave new opportunities for getting faster results of SARS-CoV-2 genome detection 24 h a day. In our study, we show, with a multivariate analysis, that the use of the POCT COVID-19 IDNOW reduced the ED length of stay by 1 h. The rate of patients who waited less than 4 h in the ED increased significantly. Our study highlights the benefit of COVID-19 molecular POCT for preventing ED overcrowding and facilitating bed allocation and SARS-CoV-2-infected patient isolation.

Universal SARS-CoV-2 Testing of Emergency Department Admissions Increases Emergency Department Length of Stay

Study objective

Our institution experienced a change in SARS-CoV-2 testing policy as well as substantial changes in local COVID-19 prevalence, allowing for a unique examination of the relationship between SARS-CoV-2 testing and emergency department (ED) length of stay.

Methods

This was an observational interrupted time series of all patients admitted to an academic health system between March 15, 2020, and September 30, 2020. Given testing limitations from March 15 to April 24, all patients receiving SARS-CoV-2 tests were symptomatic. On April 24, testing was expanded to all ED admissions. The primary and secondary outcomes were ED length of stay and number needed to test to obtain a positive, respectively.

Results

A total of 70,856 patients were cared for in the EDs during the 7-month period. The testing change increased admission length of stay by 1.89 hours (95% confidence interval 1.39 to 2.38). The number needed to test was 2.5 patients and was highest yield on April 1, 2020, when the state positivity rate was 39.7%; however, the number needed to test exceeded 170 patients by Sept 1, 2020, at which point the state positivity rate was 0.5%.

Conclusion

Although universal SARS-CoV-2 testing of ED admissions may meaningfully support mitigation and containment efforts, the clinical cost of testing all admissions amid low community positivity is notable. In our system, universal ED SARS-CoV-2 testing was associated with a 24% increase in admission length of stay alongside the detection of only 1 positive case every other day. Given the known harms and risks of ED boarding and crowding, solutions must be developed to support regular operational flow while balancing infection prevention needs.

Clinical impact of rapid influenza PCR in the adult emergency department on patient management, ED length of stay, and nosocomial infection rate

BACKGROUND

Seasonal influenza causes significant morbidity and mortality and incurs large economic costs. Influenza like illness is a common presenting concern to Emergency Departments (ED), and optimizing the diagnosis of influenza in the ED has the potential to positively affect patient management and outcomes. Therapeutic guidelines have been established to identify which patients most likely will benefit from anti-viral therapy.

OBJECTIVES

We assessed the impact of rapid influenza PCR testing of ED patients on laboratory result generation and patient management across two influenza seasons.

METHODS

A pre-post study was performed following a multifaceted clinical redesign including the implementation of rapid influenza PCR at three diverse EDs comparing the 2016-2017 and 2017-2018 influenza seasons. Testing parameters including turn-around-time and diagnostic efficiency were measured along with rates of bed transfers, hospital-acquired (HA) influenza, and ED length of stay (LOS).

RESULTS

More testing of discharged patients was performed in the post-intervention period, but influenza rates were the same. Identification of influenza-positive patients was significantly faster, and there was faster and more appropriate prescription of anti-influenza medication. There were no differences in bed transfer rates or HA influenza, but ED LOS was reduced by 74 minutes following clinical redesign.

CONCLUSIONS

Multifaceted clinical redesign to optimize ED workflow incorporating rapid influenza PCR testing can be successfully deployed across different ED environments. Adoption of rapid influenza PCR can streamline testing and improve antiviral stewardship and ED workflow including reducing LOS. Further study is needed to determine if other outcomes including bed transfers and rates of HA influenza can be affected by improved testing practices.