Original Contributions
Implementation of an emergency department triage procedure for the detection and isolation of patients with active pulmonary tuberculosis

Presented at the annual meeting of the Society for Academic Emergency Medicine, May 1994, Washington, DC.
https://doi.org/10.1016/S0196-0644(00)70050-3Get rights and content

Abstract

Study objectives: To investigate the ability of an emergency department screening protocol to initiate respiratory isolation of patients with pulmonary tuberculosis at ED triage before chest radiography. Methods: We conducted a prospective cohort study with retrospective medical record review of adult patients who presented for care to an urban, university-affiliated hospital in Los Angeles County over a 4-month period. Ambulatory patients were administered a triage screening protocol that used patient-reported tuberculosis risk factors and symptoms in combination with selective chest radiography to screen patients at ED triage for active pulmonary tuberculosis. Results: A total of 10,674 patients were screened; 2,218 were isolated at triage and underwent chest radiography, and 378 were kept in isolation in the ED. The respiratory isolation of pulmonary tuberculosis (RIPT) protocol detected 17 of 27 visits made by patients with unsuspected pulmonary tuberculosis, yielding a sensitivity of 63% (95% confidence interval [CI] 42% to 81%). The estimated specificity was 78%. For each patient with tuberculosis who was detected by the RIPT protocol, 624 patients were screened at triage, 130 chest radiographs were taken, and 22 patients were placed in respiratory isolation in the ED. Patients with undetected pulmonary tuberculosis more commonly had nonpulmonary chief complaints (76% versus 20%; odds ratio [OR] 13, 95% CI 2.1 to 78.3), and only 60% (95% CI 26% to 88%) were ultimately isolated in the hospital. Among RIPT screen-positive patients, radiographic findings predictive of pulmonary tuberculosis were cavitary lesions (OR 84.3, 95% CI 22.6 to 315), upper lobe infiltrates (OR 24.2, 95% CI 9.1 to 64.4), pleural effusions (OR 8.9, 95% CI 2.5 to 31.8), diffuse/interstitial infiltrates (OR 5.7, 95% CI 1.8 to 17.9), and non–upper lobe infiltrates (OR 3.1, 95% CI 1.0 to 9.5). Conclusion: The RIPT screening protocol was only moderately sensitive for isolating patients with pulmonary tuberculosis at ED triage. Future studies should evaluate modified and abridged screening protocols, as well as the cost-effectiveness of triage screening. [Sokolove PE, Lee BS, Krawczyk JA, Banos PT, Gregson AL, Boyce DM, Lewis RJ. Implementation of an emergency department triage procedure for the detection and isolation of patients with active pulmonary tuberculosis. Ann Emerg Med. April 2000;35:327-336.]

Introduction

Tuberculosis has resurfaced as a serious threat to public health and health care workers. In the mid-1980s, the number of tuberculosis cases in the United States began to rise, following a long trend of declining cases.1 Many nosocomial tuberculosis outbreaks have since been reported that have resulted in purified-protein derivative (PPD) skin test conversions and cases of active pulmonary tuberculosis among health care workers.2, 3, 4, 5 The emergence of multidrug-resistant tuberculosis has added to the difficulty in treating and controlling the spread of this disease, and these strains may be more likely to result in health care workers’ purified protein derivative (PPD) conversions.6, 7

Emergency department personnel are at significant risk of tuberculosis exposure, especially in urban health care facilities that care for many indigent patients. Patients at high risk for tuberculosis, including those with HIV infection, homeless, foreign-born, chronically ill, intravenous drug users, or who reside in nursing homes, are commonly treated in the nation’s EDs. The risk to ED personnel is further increased by delays in recognition and respiratory isolation of patients with active pulmonary tuberculosis.8, 9, 10 In a recent study of hospitalized patients with tuberculosis, the median interval from admission to initiation of antituberculous chemotherapy was 6 days, and 75% of patients had a delay of at least 24 hours.11

Tuberculosis is often not initially suspected because symptoms may be nonspecific, patients usually present to the ED for care without a known prior diagnosis of tuberculosis, and the clinical and radiographic presentation of tuberculosis can be misleading in HIV-infected patients.12, 13, 14, 15, 16 In a 1994 study at our institution, it was noted that 31% of ED personnel converted their PPD status to positive at some time during their ED employment, with risk of PPD-conversion increasing with duration of ED employment.17

Because of the resurgence of tuberculosis and the risk to health care workers, in 1994 the Centers for Disease Control and Prevention issued recommendations for tuberculosis infection control in health care facilities.18 This included the screening of patients at triage for signs and symptoms suggestive of tuberculosis. The ED is a potentially important site for the control of tuberculosis infection, because it serves as a point of entry for tuberculosis patients to the hospital and may allow for surveillance of tuberculosis in the community.

In response to the high PPD conversion rate seen at our institution, a triage screening protocol was developed for the rapid identification and isolation of patients at risk of active pulmonary tuberculosis. This study was undertaken to evaluate the ability of this protocol to identify and isolate patients seeking care in the ED who have unsuspected active pulmonary tuberculosis. Our secondary objective was to describe the ED triage presentation of patients with active pulmonary tuberculosis.

Section snippets

Materials and Methods

Harbor-UCLA Medical Center is an urban, university-affiliated hospital that serves a predominantly medically indigent population in Los Angeles County. The adult ED has an annual census of approximately 60,000 patients. A triage screening instrument was developed using tuberculosis risk factors and symptoms identified from the literature. This was known as the Rapid Isolation of Pulmonary Tuberculosis (RIPT) screen. Each risk factor and symptom was weighted by assigning a point value based on

Results

During the 4-month study period, 10,674 patients were screened using the RIPT screening instrument. Based on review of triage logs, this represents 91% of all patients seen in the ED during that period. Of the screened patients, 2,302 (22%) reported sufficient risk factors, symptoms, or both to warrant immediate respiratory isolation and chest radiography (Figure 1).

. Results of RIPT screening protocol for screening of adult patients at triage during the study period (November 15, 1993, through

Discussion

Screening patients at ED triage for pulmonary tuberculosis is a difficult task. The ideal screening instrument would be easy to administer, have a high sensitivity and specificity, and therefore result in few unnecessary chest radiographs or isolation events. The RIPT screening instrument had a sensitivity of 63% in our study, which we view as disappointing. On the other hand, on average this protocol resulted in the respiratory isolation at triage of 1 patient per week with otherwise

References (20)

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Address for reprints: Peter E. Sokolove, MD, Division of,Emergency Medicine, UC Davis Medical Center, 2315 Stockton Boulevard, PSSB 2100, Sacramento, CA 95817; 916-734-1534,fax 916-734-7950; E-mail [email protected] .

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