Measures for Reducing Nosocomial Infections in a Tertiary Care Hospital — an Interventional Study With Before-and-After Comparison

The “HygArzt” research project investigated whether the authorized medical specialist in the department of orthopedic and trauma surgery nominated as an infection prevention link physician (PLP) can improve hand hygiene adherence (HHA), nosocomial infection (NI) and surgical site infection (SSI) rates by implementing a bundle of infection prevention measures (IPB). This study is part of the prospective multicenter cohort study “HygArzt” and presents data from the pilot hospital.

Methods

In the presented monocentric part of the cohort intervention study, three regular orthopedic and trauma surgery wards with a total capacity of 113 beds were investigated at a university hospital (1). The aim of this study was to identify possible associations between the bundle of infection prevention measures to be implemented and the reduction of nosocomial infections, especially surgical site infections, and the increase in hand hygiene adherence (Figure). All patients in the orthopedic and trauma surgery department who were treated and underwent surgery as inpatients on a regular ward in the periods from 1 March to 31 August 2018 (pre-phase) and from 1 January to 30 June 2019 (post-phase) were included in the study. Persons with pre-existing infections present on admission were excluded. The infection prevention link physician (PLP) implemented the IPB during the intervention phase between 1 September 2018 and 31 December 2018. The components of the IPB were compiled based on a systematic search the literature on infection prevention measures in orthopedic and trauma surgery (2) (Figure). Patients were screened for methicillin-resistant Stapylococcus aureus (MRSA) and methicillin-sensitive Stapylococcus aureus (MSSA) by nasal swab at the time of registration for surgery in the Central Patient Management. If the MRSA test was positive, an eradication treatment was carried out, while in case of a positive MSSA test, the decolonization strategy was implemented (Figure). Primary endpoints of the study were nosocomial infections—which were prospectively recorded according to the definitions of the German National Reference Center for Surveillance of Nosocomial Infections (NRC) and the Centers for Disease Control and Prevention (CDC)—and deaths (for information on the methodological approach, see [1]). The relative risk (RR) for the infection rates in the pre/post comparison and 95% confidence intervals (CIs) were determined. The Chi-square test of independence (χ² test) was used to calculate statistical differences in hand hygiene adherence. The significance level was set at p<0.05.

Figure

Measures and implementation of the bundle of infection prevention measures

Results

In the pre-phase of the study, 1676 surgeries were performed on 1324 patients, of whom 1211 were included with 1430 surgeries. In the post-phase, 1722 surgeries were performed on 1319 patients, of whom 1269 were included with 1583 surgeries. In the pre-post comparison, an increase in overall hand hygiene adherence on the ward and in the operating room was found (Table). The nosocomial infection (NI) rate was lowered from 4.1% to 2.2% (RR = 0.53; 95% confidence interval [0.35; 0.80]) and the surgical site infection (SSI) rate from 3.1% to 1.6% (RR = 0.53; [0.33; 0.86]) (Table). In neither the pre- nor the post-phase of the study did any deaths occur. In case of surgical site infections, infections with S. aureus (pre N = 19, post N = 12), coagulase-negative cocci (pre N = 14, post N = 8) and enterobacteria (pre N = 8, post N = 4) were most frequently detected, both in the pre- and post-phase.

Table

Study results of overall adherence rates and infection rates before and after implementation of an intervention bundle

Discussion

In our study, implementation of a bundle of infection prevention measures by an infection prevention link physician (PLP) was associated with an increase in HHA rate and a reduction in NI and SSI rates. On the wards, the overall HHA increased to 81.4% in the post-phase which exceeded the nationwide reference value for regular surgical wards in Germany of 78% (3). The overall HHA in the OR was increased from 12.6% in the pre-phase to 52.2% after the intervention, but was at the same time lower than in the study by Menzel et al. (4) which found an overall HHA of 75% in the OR after implementation of an intervention (4). In our study, there was no regular feedback of HHA data and no hands-on training in the OR, unlike in the wards, a fact that may explain the lower adherence compared with the study by Menzel et al. (4) and with the adherence rates found in the wards.The development of the IPB was carried out in an interprofessional and interdisciplinary manner and took into account the local conditions and processes in the wards and in the operating room. As part of the orthopedic and trauma surgery department, the infection prevention link physician (PLP) had the knowledge required for the task. The presence of an observer may have produced the Hawthorne effect and thus unintentionally enhanced HHA as a result of the observation situation. However, an influence of the Hawthorne effect on the pre/post phase comparison was not to be expected, since it would have had an effect in both phases. Washing with an antiseptic combined with mupirocin-containing nasal ointment was already shown to be effective in reducing SSI rates in the study by Bode et al. (5) in which a reduction from 7.7% to 3.4% was achieved using chlorhexidine (5). By combining nasal ointment, preoperative antiseptic washing and other measures, we were able to reduce the low pre-phase surgical site infection rate in the post-phase of our study. In summary, implementation of IPB by an infection prevention link physician (PLP) proved to be a promising strategy to significantly increase hand hygiene adherence and significantly reduce NI and SSI rates.

Meike M. Neuwirth, Benedikt Marche, Jan Hoffmann, Jerome Defosse, Frauke Mattner, Robin Otchwemah

Acknowledgement

We thank Regine Galante, Ina-Kathrin Dombrowski and Selda Akca for their assistance with data collection of outcome parameters and collection of adherence observations, respectively, and the Central Patient Management staff for dispensing the antiseptic wash lotions and antibiotic nasal ointments, as well as all who consented to the observation.

Funding

The study was funded by the German Federal Ministry of Health (BMG, Bundesministerium für Gesundheit) (funding code: ZMV11–2516FSB111).

Conflict of interest
The authors declare no conflict of interest

Translated from the original German by Ralf Thoene, MD

Manuscript received on 19 December 2022, revised version accepted on 23 March 2023

Cite this as:
Neuwirth MM, Marche B, Hoffmann J, Defosse J, Mattner F, Otchwemah R: Measures for reducing nosocomial infections in a tertiary care hospital—an interventional study with before-and-after comparison. Dtsch Arztebl Int 2023; 120: 536–7. DOI: 10.3238/arztebl.m2023.0086

References

1. Neuwirth MM, Marche B, Kugler C, et al.: Evidence of the medical and economic benefits of implementing hygiene measures by a prevention link physician in trauma surgery: Study protocol for a biphasic multicenter prospective interventional pre-post cohort study using a structured intervention bundle development and tools of behavior change management. Contemp Clin Trials Commun 2021; 23: 100815

2. Marche B, Neuwirth M, Kugler C, Bouillon B, Mattner F, Otchwemah R: Correction to: Implementation methods of infection prevention measures in orthopedics and traumatology—a systematic review. Eur J Trauma Emerg Surg 2021; 47: 1015

3. Institut für Hygiene und Umweltmedizin Charité Universitätsmedizin Berlin: „Aktion Saubere Hände“ Compliance Beobachtungen – Referenzdaten Berechnungszeitraum: Januar 2020 bis Dezember 2020. www.aktion-sauberehaende.de/fileadmin/ash/user_upload/pdf/Referenzdaten/202001_202012_ComplianceReference_Alle_Stationen_DE.pdf (last accessed on 19 May 2022).

4. Menzel J, Kühn A, Beck D, Schock B, Chaberny IF: [Hand hygiene in the operating room (OR)-(not) an issue?]. Unfallchirurg 2022; doi: 10.1007/s00113–022–01181–0. Online ahead of print

5. Bode LGM, Kluytmans JAJW, Wertheim HFL, et al.: Preventing surgical-site infections in nasal carriers of staphylococcus aureus. N Engl J Med 2010; 362: 9–17