A Quality Improvement Project to Increase Pharmacist-Initiated Methicillin Resistant Staphylococcus Aureus Nasal Swab PCR for Vancomycin De-Escalation in Pediatric Patients With Respiratory Tract Infections

Abstract

OBJECTIVE

Overuse of broad-spectrum empiric antimicrobials remains common in children hospitalized with respiratory tract infections (RTI). A negative methicillin-resistant Staphylococcus aureus (MRSA) nasal swab (MNS) polymerase chain reaction (PCR) result has been shown to have a high negative predictive value for MRSA in RTI. In this quality improvement (QI) initiative, we developed a pharmacist-driven approach to reduce the duration of empiric vancomycin for RTI in children. The primary aim was the time to de-escalation of vancomycin, and the secondary aim was the reduction in vancomycin monitoring in patients hospitalized with RTI.

METHODS

Baseline duration of vancomycin therapy was assessed by conducting a retrospective chart review. After root cause analysis and engaging key stakeholders, an electronic health record OurPractice Advisory (OPA) was implemented, prompting pharmacists to order an MNS PCR during order verification for vancomycin with an RTI indication.

RESULTS

Preimplementation (01/01/2021 to 08/31/2023) included 89 patients, and 25 postimplementation (09/21/2023 to 05/31/2024). We found a 36% decrease in mean vancomycin duration from 53 to 34 hours after implementation of the pharmacist-driven OPA. Postimplementation, 24% of patients had a vancomycin concentration obtained, compared with 37% preimplementation. No patients were readmitted within 30 days postimplementation, compared with 1 patient preimplementation.

CONCLUSIONS

This QI initiative provides preliminary data that empiric vancomycin duration in pediatric patients with RTI may be impacted by pharmacist-facing OPA implementation, prompting ordering of MNS PCR at the time of vancomycin verification. This initiative could be replicated at other institutions seeking to reduce empiric vancomycin usage.

Introduction

Methicillin-resistant Staphylococcus aureus (MRSA) can cause severe infections requiring hospitalization in children.¹ Concern for MRSA infections in children has resulted in increased use of anti-MRSA antibiotics as part of empiric treatment regimens for many common infectious syndromes.² Nasal swabs that detect MRSA colonization, either via culture or polymerase chain reaction (PCR) methods, have been identified as a tool with high negative predictive value, greater than 90%, that can be used to safely guide the de-escalation of anti-MRSA antibiotics in adult patients with lower RTI.^3–9 Recent studies have similarly demonstrated high negative predictive values in pediatric patients, equipping the care team with a reliable tool for confidently de-escalating anti-MRSA antibiotics when the nasal swab does not detect the presence of MRSA.^10–16 However, the use of MRSA nasal swabs (MNS) has not been broadly or systematically standardized in most pediatric settings. Some benefits of MNS PCR include ease of laboratory processing and rapid turnaround time (typically within hours) compared with other microbiological cultures, which require more prolonged incubation and are often difficult to obtain in children (e.g., sputum cultures) or require invasive procedures, such as bronchoalveolar lavage, for high-quality sampling.

Multiple studies have evaluated the impact of pharmacist-driven MNS testing and education in adult patients.^17–24 All of these studies found that a pharmacist-driven MNS PCR protocol and education resulted in a significant reduction in duration of empiric anti-MRSA therapy. These studies emphasize the contribution that clinical pharmacists can make within a multidisciplinary team and their positive impact on antimicrobial stewardship. Therefore, our team initiated a quality improvement (QI) project, using Six Sigma and the Define, Measure, Analyze, Improve, Control methodology, to develop a pharmacist-facing approach to improve the use of MNS PCRs to aid de-escalation of vancomycin in pediatric patients with RTI.

Materials and Methods

A retrospective chart review was conducted between January 1, 2021, and August 31, 2023, to assess the baseline duration of empiric vancomycin for RTI indication in pediatric patients hospitalized within the Mayo Clinic Enterprise. The Mayo Clinic Enterprise includes the main children’s hospital in Rochester, Minnesota, with 148 beds, and other limited pediatric patient admissions at Mayo Clinic Health System sites in Minnesota, Wisconsin, Arizona, and Florida. Patients were included in the preimplementation analysis if they were 29 days old or younger than 18 years of age, inpatients, and had a vancomycin order with a community- or hospital-acquired RTI indication. At our institution, an active infection prevention and control surveillance protocol exists for infants admitted to the neonatal intensive care unit, which consists of screening for staphylococcal colonization at admission and then weekly. All patients in the neonatal intensive care unit were therefore excluded, as the indication for obtaining the MNS was infection prevention and control, not a respiratory indication.

Additionally, patients who expired within 30 days of discharge were also excluded. After baseline data were collected, stakeholders were identified and a stakeholder analysis conducted. Stakeholders included pharmacists, pediatric infectious diseases physicians, pediatric medical providers (including residents), informatics, lab personnel, patients, and nursing. This stakeholder analysis was then used to identify gaps in quality using a fishbone diagram (Figure 1) to determine factors that were impacting inappropriate and prolonged durations of vancomycin. The identified factors were divided into the following 4 major categories: patient, prescriber, institutional, and diagnostic factors. After identification of these factors, an impact-effort matrix (Figure 2) was created. The following 4 factors were identified as low-effort, high-impact intervention areas: discomfort with de-escalation without culture guidance, the use of the incorrect nasal swab resulting in automatic cancellation of the lab, the lack of education on MNS PCR negative predictive value, and the lack of consistent collection of MNS PCR and cultures at the time of admission. To help target these factors, the primary intervention focused on creating a pharmacist-driven MNS screening protocol to guide the de-escalation of empiric vancomycin.

Figure 1.

Fishbone diagram used by stakeholders to identify factors impacting vancomycin use.

Figure 2.

Impact effort grid used to categorize factors identified in Figure 1 that impacted vancomycin.

As part of the MNS PCR protocol, informatics built an OurPractice Advisory (OPA) that was implemented in the electronic health record to prompt pharmacists to order an MNS PCR during verification of vancomycin orders with an RTI indication. The OPAs are pop-up alerts within the Epic system that relay relevant clinical information about the patient to the clinician to help facilitate related workflows. The OPAs were previously referred to as a best practice advisory. The OPA we have built triggers if the patient is 29 days or less than 18 years old. It will not trigger if the patient had intranasal mupirocin ordered during the current admission, already had an MNS PCR ordered within the last 7 days, was MRSA-positive during the current encounter, or had received more than 12 doses of vancomycin within the last 7 days. The OPA was implemented on September 21, 2023, and a post-OPA implementation chart review was conducted between October 1, 2023, and May 31, 2024. Education regarding the clinical use of MNS PCR and its negative predictive value was also provided to pharmacists, nurses, medical residents, and providers to supplement the OPA implementation. During education, images of the correct specimen collection materials were also displayed to decrease the number of lab cancellations due to use of incorrect collection media. Finally, an infographic was developed to summarize and reinforce key concepts of the initiative and was prominently displayed in the pharmacy and residents’ workrooms.

The primary aim of this QI project was to reduce the time to de-escalation of vancomycin, and the secondary aim was to reduce drug concentration monitoring of vancomycin for RTI indications. The percentage of MNS ordered by a provider versus a pharmacist was also evaluated. The counterbalance measure assessed was readmission to the emergency department or hospital within 30 days of index hospitalization for concerns of worsening respiratory status or pneumonia and culture result necessitating vancomycin therapy. Therefore, patients who expired during their admission or within 30 days after admission were excluded. The primary goal of this project was to decrease vancomycin duration by 30%.

Results

A total of 141 patients were identified who received vancomycin for an RTI; 27 patients were excluded, leaving 114 for analysis. Eighty-nine patients before the OPA intervention, and 25 patients after the intervention, were evaluated (Table 1). Before the OPA intervention, the mean (± SD) duration of vancomycin was 53 (± 57) hours, and the median duration was 40 hours (range, 3–323). After implementation of the pharmacist-facing OPA, the mean duration was 34 (± 25) hours and the median was 24 hours (range, 2–91), resulting in a 36% decrease in the mean duration of vancomycin (Table 2). This reduction was achieved by pharmacists alerting the provider of an MNS result and recommending the discontinuation of vancomycin therapy. The final decision regarding when to discontinue vancomycin was made by the provider. The mean number of vancomycin doses also declined by 25%, from 8 (± 8) doses preimplementation to 6 (± 4) doses postimplementation. Coinciding with this decline was a concomitant decline in the number of vancomycin concentrations ordered. Most patients have vancomycin concentration (trough monitoring) obtained on day 2 of therapy if a duration of more than 48 hours is expected. There is no standard protocol for the frequency of repeating levels, as this is dependent on many patient- and clinical-syndrome-specific factors (e.g., patient age, type of infection being treated, renal function, etc.). Typically, we check vancomycin concentrations with the fourth dose and only repeat if drug changes are made, changes in renal function, or the patient has been on vancomycin for more than 5 days. Therefore, the reduced duration of vancomycin also reduced the number of concentrations obtained. Preintervention, the number of patients that had at least 1 vancomycin concentration obtained was 37%, and postintervention decreased to 24%.

Table 1.

Patient Characteristics

Characteristic	Preintervention (n = 89)	Postintervention (n = 25)
Age, yr, mean (SD)	7.3 (5.7)	6.8 (4.7)
Female sex, n (%)	44 (49)	9 (36)
Immunocompromised,* n (%)	20 (22)	3 (12)
Location at time of nasal swab, ICU, n (%)	62 (70)	13 (52)

ICU, intensive care unit

* Any patient with hematology or oncology, hematopoietic cell transplant, solid organ transplant, undergoing transplant evaluation, or HIV.

Table 2.

Vancomycin Duration and Number of Doses

	Preintervention (n = 89)	Postintervention (n = 25)
Duration of vancomycin, hr, mean ± SD	53 ± 57	34 ± 25
Duration of vancomycin, hr, median (range)	40 (3–323)	24 (2–91)
Vancomycin doses administered, mean ± SD	8 ± 8	6 ± 4
Vancomycin doses administered, median (range)	7 (1–51)	5 (1–16)
Vancomycin concentrations ordered, n (%)
0	56 (63)	19 (76)
1	22 (25)	4 (16)
2	4 (5)	1 (4)
3	3 (3)	1 (4)
4	2 (2)	0
5	1 (1)	0
6	1 (1)	0

Additionally, during the baseline review of patients, 47% of patients with vancomycin orders for RTI had a concurrent MNS PCR ordered, all of which were ordered by physicians. After implementation, this increased to 80%, with 64% ordered by physicians and 36% ordered by pharmacists. During the baseline period, 5 patients had MNS canceled due to incorrect collection media used and only 1 patient in the postimplementation period. Finally, this QI initiative also evaluated readmission data as a counterbalance measure. Preimplementation, 1 patient was readmitted or restarted on empiric anti-MRSA therapy for an RTI, and postimplementation, there were no patients.

Discussion

We implemented an OPA to alert pharmacists when vancomycin was ordered for an RTI for a pediatric patient who did not have an MNS PCR ordered. This QI project demonstrated reductions in the duration of empiric vancomycin for RTI indications, the number of vancomycin doses administered, and the percentage of patients with a vancomycin drug concentration obtained, without increasing readmission rates. Throughout the project, feedback was solicited on rounds and during MNS informational sessions for providers and pharmacy staff, and was overwhelmingly positive. Based on the results of this project, this process change will continue to be used for all vancomycin orders for RTI in pediatric patients meeting the inclusion criteria. In the future, other indications may be incorporated into the OPA as we learn more about MNS reliability for those indications globally and at our institution.

There were several limitations to this project. Owing to the retrospective nature, information was limited to documented information in the electronic health record. There was also a smaller number of patients in the postimplementation group compared with the preimplementation group. Therefore, statistical analysis was not performed, and the reduction could be due to clinical variation. Additionally, the readmission rate may be underrepresented because patients may have presented to hospitals outside our healthcare system for treatment of the same RTI. Lastly, we excluded patients who expired within 30 days of discharge; however, this could understate readmission rates and mortality due to MRSA infections, but none of the patients excluded expired due to MRSA infection.

There were 3 main lessons learned throughout the project as follows: 1) engagement from pharmacists and department stakeholders was critical to project success to ensure knowledge retention and confidence with the use of the OPA and process for end users ordering MNS; 2) the use of the Fishbone diagram lent itself to identification of drivers of inappropriate vancomycin use that individual members may not have considered before the exercise with the QI team and stakeholders; and 3) the addition of the OPA to the electronic medical record heightened awareness and questions asked by providers and staff facilitated continuous education, which likely positively impacted educational durability to stakeholders.

Conclusion

This QI project provides preliminary data that empiric vancomycin use in pediatric patients may be impacted by implementing a pharmacist-driven OPA to order MNS PCR when vancomycin is ordered with an RTI indication. This QI initiative could be used by other healthcare institutions seeking to safely decrease vancomycin overuse in pediatric patients.

ABBREVIATIONS

MNS

methicillin-resistant Staphylococcus aureus nasal swab;

MRSA

methicillin-resistant Staphylococcus aureus;

OPA

OurPractice Advisory;

PCR

polymerase chain reaction;

QI

quality improvement;

RTI

respiratory tract infection