Role of Anesthesia Providers in Infection Control

In order to understand how to prevent HAIs, one must first characterize the magnitude and implications of the problem. Contamination in the anesthesia work area increases significantly from case start to case end. For example, the adjustable pressure-limiting valve and agent dial of the anesthesia machine represent a significant proportion of environmental contamination (Anesthesiology 2008;109:399-407). There are multiple routes to environmental contamination, with anesthesia provider hands and patient skin surfaces as important reservoirs of origin for potential and major bacterial pathogens (Anesth Analg 2012;114:1236-48). Bacterial organisms originating on provider hands before, during, and after care, and on patient skin surfaces such as the axilla, nasopharynx, and groin, can be transmitted from those locations to the anesthesia machine during the process of patient care. For example, bacteria can be transferred from the patient’s axilla to the anesthesia provider’s hands when placing electrocardiogram leads and then to the anesthesia machine during induction. Once contamination of the anesthesia machine reaches 100 colony forming units (CFUs), the risk of patient intravenous stopcock contamination increases (Anesthesiology 2008;109:399-407). This association remains significant despite adjustment for potentially confounding variables including, but not limited to, markers of disease severity such as number of patient comorbidities and the ASA health classification score (Anesthesiology 2008;109:399-407). In turn, stopcock contamination has been repeatedly associated with increased patient mortality (Anesthesiology 2008;109:399-407; Anesth Analg 2012;114:1236-48). This association has clear face validity given that intravenous catheters are in direct continuity with the patient’s bloodstream and, as such, prevention of such contamination is not only logical but clearly indicated. Transmitted bacteria have also been repeatedly linked to infection development (Anesthesiology 2008;109:399-407; Anesth Analg 2012;114:1236-48). In fact, at least 30% of HAIs are caused by bacteria present in one or more anesthesia work area reservoirs, where pulsed-field gel electrophoresis and/or whole genome sequencing have linked the causative organism of infection within 30-90 days from surgery to the same organism present during the procedure (Anesth Analg 2012;114:1236-48). Given the specificity of such testing, these links represent only the tip of the iceberg.

Because organisms are present during the procedure, there is clearly an opportunity for prevention of transmission. Anesthesia provider hands, the environment, and contaminated patient skin surfaces contribute to stopcock transmission events, indicating a need for a multimodal solution (Anesth Analg 2012;114:1236-48). In other words, prevention of transmission, or movement, of bacterial organisms to the patient intravenous stopcock set would not generally occur with a single preventive measure, such as hand hygiene, because hands are intricately related to the environment and patient skin surfaces. Optimal prevention would instead require a bundled format, with improved hand hygiene, environmental cleaning, and patient decolonization.

Much work has assessed both the efficacy and effectiveness of infection control measures to address the four key pillars of infection control (hand hygiene, environmental cleaning, vascular care, and patient decolonization) (JAMA Netw Open 2020;3:e201934; J Clin Anesth 2023;85:111043). The anesthesia professional’s use of a novel, personalized body-worn alcohol dispenser is associated with increased hourly anesthesia provider hand hygiene events and reduced environmental and stopcock contamination and HAIs (Anesthesiology 2009;110:978-85). Anesthesia provider use of a catheter care station can reduce stopcock contamination and HAIs (Anesth Analg 2012;115:1315-23). Improved organization of the anesthesia work area, as well as increased frequency and quality of cleaning, including post-induction cleaning of the anesthesia machine and equipment, is associated with a reduction in the proportion of measured reservoirs that return ≥100 CFU (Am J Infect Control 2014;42:1223-5). Patient decolonization can also reduce surgical site infections (JAMA Surg 2015;150:390-5). Feedback can help to optimize behavioral interventions (JAMA Netw Open 2020;3:e201934). Anesthesia provider implementation of a multifaceted approach incorporating these evidence-based improvement strategies, thereby addressing the four key pillars of perioperative infection control, can generate substantial reductions in S. aureus transmission and surgical site infections (SSIs) (J Clin Anesth 2023;85:111043). Most patients undergoing anesthesia stand to benefit from these efforts (Can J Anaesth 2023;70:1330-9). Recent work shows that patient, environmental, provider hand, and stopcock reservoirs are implicated in ≥5% of transmission events in the anesthesia work area, providing further support for the multifaceted approach (J Clin Anesth 2024;92:111303). As 17% of syringe tips are contaminated, ongoing work to improve perioperative infection control is indicated (Br J Anaesth 2023;131:e112-4).

Most importantly, in addition, these interventions are practical and cost-saving. In one study, the baseline SSI rate was 4.1%; however, when there was no detected S. aureus transmission through the anesthesia work area, the SSI rate was 2%. Therefore, transmission preventable infection by anesthesia practitioners accounts for approximately half of SSIs (J Hosp Infect 2023;134:121-8). SSI prevention is also cost-saving. The total estimated reduction in costs from SSIs: (1-0.45) × 6.7% × 1817 × $24,185 = $1,619,342 (J Clin Anesth 2024;92:111303).

In summary, anesthesia professionals are well-positioned to minimize the incidence of perioperative infections to reduce patient harm, further improve perioperative infection control efforts, and reduce health care expenditures. Our patients’ safety and the future of our health care system demand a timely response to this solid foundation of evidence.