Procalcitonin-Guided Antibiotic Prescribing for Acute Exacerbations of Chronic Obstructive Pulmonary Disease in the Emergency Department
Purpose: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) can be caused by viral, bacterial, or environmental factors. Recent studies have suggested that procalcitonin serum levels may help reduce unnecessary antibiotic use without statistically significant differences in rates of treatment failure for AECOPD. The purpose of this quality improvement project was to create a procalcitonin-based algorithm to aid emergency department (ED) clinicians in the management of patients with AECOPD who do not require hospitalization and to evaluate its efficacy and practicality. The primary outcome of this project was the rate of antibiotic prescriptions before and after the initiation of the algorithm.
Methods: This study used an observational, retrospective, pre- and posteducation/intervention design. Clinicians were educated individually on the use of procalcitonin, and a copy of the algorithm was made available to each clinician and posted in the ED. Patients who were discharged from the ED with a diagnosis of an AECOPD were identified using International Classification of Diseases , Tenth Revision codes. Patient charts were reviewed from November 2018 to March 2019 for the preimplementation period and November 2019 to March 2020 for the postimplementation period. The rate of antibiotic prescriptions and the number of procalcitonin tests ordered before and after the introduction of the algorithm were analyzed. In addition, information on COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) grouping and 30-, 60-, and 90-day reexacerbation rates were collected. It was estimated that a sample size of 146 patients (73 patients/group) would provide 80% power to detect a between-group difference of 10% in the percentage of patients who were prescribed antibiotics. Categorical variables were expressed using estimates of their frequency and percentages. Percentages were compared using Fisher exact tests. For all tests, the significance level was set at 0.05.
Results: Seventy-three patients were included in the preintervention group, and 77 patients were included in the postintervention group. Patients in the preintervention and postintervention groups had similar representation in GOLD categories: 52% and 51% for D, 17.8% and 23.4% for C, 21.9% and 16.8% for B, and 8.2% and 7.8% for A, respectively. The rate of antibiotic prescriptions decreased by 20% after implementation from 83.6% before to 63.6% after implementation ( P = .01). The differences in reexacerbation rates between the preintervention and postintervention groups were similar: 19.2% vs 23.4% at 30 days, 12.3% vs 11.7% at 60 days, and 4.1% vs 9.1% at 90 days, respectively. Prior to education and introduction of the procalcitonin algorithm, procalcitonin was ordered for 1.4% of AECOPD cases. Postimplementation, procalcitonin was ordered for 28.6% of AECOPD cases and used in clinical decision making 81.8% of the time .
Conclusions: In this study of the implementation of a treatment algorithm for patients with mild and moderate AECOPD who present to the ED, procalcitonin was shown to reduce the rate of antibiotic prescriptions without an observable difference in reexacerbation rates 30, 60, and 90 days after presentation.
Strengths
Strengths of this project include its multimodal implementation and overall pragmatic design, which reflects real-world utilization of procalcitonin by ED HCPs. The HCPs were not mandated to follow the procalcitonin algorithm, and the use of clinical judgment was strongly encouraged. This project occurred concomitantly with the VA Infectious Disease Academic Detailing education program. The program focused on clinician education for the proper diagnosis and treatment of respiratory tract infections. In addition, viral illness packs were introduced as part of this initiative to reduce unnecessary antibiotic prescribing. The viral illness pack included standard items for symptom relief, such as saline nasal spray, cough drops, and hand sanitizer, as well as an explanation card of why the patient was not receiving antibiotics. Several studies have suggested that patients expect a prescription for an antibiotic when they present with respiratory tract symptoms, and HCPs often are compelled to maintain patient satisfaction, thus leading to unnecessary antibiotic prescriptions.14 The viral illness pack helped fulfill the patient’s expectation to receive treatment after seeking care. In addition, the project lead was available full time during the first month of PCT algorithm implementation to address questions and concerns, which may have improved HCPs overall confidence in using PCT.
Limitations
Limitations of this project include its population and its retrospective nature. The PVAHCS patient population is predominantly older, more White, and more male compared with the general civilian population, and results may not be generalizable to other populations. Data were limited to documentation in the electronic health record. The population was based on data extraction by the ICD-10 code, which may not be an accurate capture of the total population as HCPs may not select the most accurate ICD-10 code on documentation. Another potential limitation was the COVID-19 pandemic which may have resulted in HCPs ordering PCT more frequently as more patients presented to the ED with undifferentiated respiratory symptoms. Finally, there were minimal differences observed in reexacerbation rates; however, although the sample size was powered to detect a difference in antibiotic prescriptions, the sample size was not powered to detect a statistically significant difference in the primary safety outcome.
Conclusions
PCT-guided antibiotic prescribing significantly reduced the number of antibiotic prescriptions without an observable increase in reexacerbation rates for patients with mild and moderate AECOPD in the ED. This study provides a pragmatic evaluation of PCT-guided antibiotic prescribing for patients with AECOPD solely in the outpatient setting. Acute phase reactants like PCT can play a role in the management of AECOPD to reduce unnecessary antibiotic prescriptions.
