Superiority of chlorhexidine 2%/alcohol 70% wipes in decontaminating ultrasound equipment

Infection Control for Perioperative Ultrasonography and Echocardiography

Ultrasound technology has revolutionized point-of-care diagnostics, decision-making, and the guidance of interventional procedures in Anesthesiology and Perioperative Medicine. Recent literature has highlighted important infection control considerations when performing transesophageal or transthoracic echocardiography, point-of-care ultrasound, and ultrasound-guided procedures. This narrative review focuses on operator precautions and disinfection methods and summarizes key recommendations from the international Echocardiography and Radiology Societies.

Combatting COVID-19: is ultrasound an important piece in the diagnostic puzzle?

The current COVID-19 pandemic is causing diagnostic and risk stratification difficulties in Emergency Departments (ED) worldwide. Molecular tests are not sufficiently sensitive, and results are usually not available in time for decision making in the ED. Chest x-ray (CXR) is a poor diagnostic test for COVID-19, and computed tomography (CT), while sensitive, is impractical as a diagnostic test for all patients. Lung ultrasound (LUS) has an established role in the evaluation of acute respiratory failure and has been used during the COVID-19 outbreak as a decision support tool. LUS shows characteristic changes in viral pneumonitis, and while these changes are not specific for COVID-19, it may be a useful adjunct during the diagnostic process. It is quick to perform and repeat and may be done at the bedside. The authors believe that LUS can help to mitigate uncertainty in undifferentiated patients with respiratory symptoms. This review aims to provide guidance regarding indications for LUS, describe the typical sonographic abnormalities seen in patients with COVID-19 and provide recommendations around the logistics of performing LUS on patients with COVID-19 and managing the infection control risk of the procedure. The risk of anchoring bias during a pandemic and the need to consider alternative pathologies are emphasised throughout this review. LUS may be a useful point-of-care test for emergency care providers during the current COVID-19 pandemic if used within a strict framework that governs education, quality assurance and proctored scanning protocols.

Comparison of Effectiveness of 70%-isopropanol, 65%-ethanol and 1%-chlorhexidine for Stethoscope Decontamination

Stethoscopes are potential vector for health care associated infections worldwide. Ethyl alcohol (EA), isopropyl alcohol (IPA) and chlorhexidine (CH) are widely used for disinfecting stethoscope, however, comparative analysis of these disinfectants are scarce. Hence this paper aims to compare the reduction in bioburden with respect to stethoscope decontamination. A randomized, double-blind study was undertaken from various categories of health care workers (HCW) working in various departments. Each participant was asked to fill a questionnaire and diaphragms of their stethoscopes were imprinted on blood agar and sabourauds dextrose agar before and after disinfection with either 65%-EA, 70%-IPA or 1%-CH. The culture plates were incubated aerobically and the growth was further identified. 384 HCW participated in the study. 168 participants never cleaned their stethoscope, out of which 147 respondents (91.6%) comprised of students. EA (47%) and IPA (23%) were the two major types of alcohols used as disinfecting agents. 280 samples showed growth among which 51.8% were potent pathogens. Before disinfection, Staphylococcus aureus (27%) was the predominant pathogen, followed by Klebsiella (6.8%), Enterococcus and Candida respectively. Among the disinfectants used, maximum antimicrobial activity was exhibited by IPA (92.5%) compared to EA (82.5%) and CH (77.8%). Huge lacunae regarding knowledge, attitude and practice of stethoscope maintenance was found among student community. The microbial growth varies at various department. Disinfecting stethoscope with 70%-IPA for just 30 seconds is equally efficient compared to 1 minute and IPA was superior to EA and CH for decontaminating stethoscope. Stethoscopes are potential vector for health care associated infections worldwide. Ethyl alcohol (EA), isopropyl alcohol (IPA) and chlorhexidine (CH) are widely used for disinfecting stethoscope, however, comparative analysis of these disinfectants are scarce. Hence this paper aims to compare the reduction in bioburden with respect to stethoscope decontamination. A randomized, double-blind study was undertaken from various categories of health care workers (HCW) working in various departments. Each participant was asked to fill a questionnaire and diaphragms of their stethoscopes were imprinted on blood agar and sabourauds dextrose agar before and after disinfection with either 65%-EA, 70%-IPA or 1%-CH. The culture plates were incubated aerobically and the growth was further identified. 384 HCW participated in the study. 168 participants never cleaned their stethoscope, out of which 147 respondents (91.6%) comprised of students. EA (47%) and IPA (23%) were the two major types of alcohols used as disinfecting agents. 280 samples showed growth among which 51.8% were potent pathogens. Before disinfection, Staphylococcus aureus (27%) was the predominant pathogen, followed by Klebsiella (6.8%), Enterococcus and Candida respectively. Among the disinfectants used, maximum antimicrobial activity was exhibited by IPA (92.5%) compared to EA (82.5%) and CH (77.8%). Huge lacunae regarding knowledge, attitude and practice of stethoscope maintenance was found among student community. The microbial growth varies at various department. Disinfecting stethoscope with 70%-IPA for just 30 seconds is equally efficient compared to 1 minute and IPA was superior to EA and CH for decontaminating stethoscope.

Surgical Loupes Worn by Orthopaedic Surgeons Are a Reservoir for Microorganisms

BACKGROUND

Surgeons frequently use optical loupes to magnify the surgical field; they are typically unprotected when positioned directly over the wound, where particulate shedding containing microorganisms could potentially lead to surgical site infections (SSIs). SSIs are rare in some orthopaedic subspecialties such as hand surgery; however, in other subspecialties, for example, the spine, where surgeons often use loupes, SSIs can have devastating consequences.

QUESTIONS/PURPOSES

(1) What is the degree of bacterial and fungi organism colonization of surgical loupes and storage cases? (2) Is there a difference in the degree of colonization at the beginning and the end of a surgery day? (3) Does an alcohol swab reduce bacterial colonization of surgical loupes?

METHODS

The surgical loupes of 21 orthopaedic surgeons from a large, regional orthopaedic practice were cultured over a 3-month period and form the basis of this study. Five loupe storage cases were also cultured. In two different subgroup comparisons, the presence of microorganisms was evaluated just before the start and immediately after the end of the surgical day (n = 9) and before and 1 minute after cleaning with an alcohol swab (n = 6). A total of 36 cultures were evaluated. Surgeons who declined to participate in the study were excluded. The number of loupes selected for all of the analyses were samples of convenience and limited by surgeon availability. The degree of bacterial and fungal presence was graded using a point system: 0 = no growth; 1 = limited growth (meaning few scattered colonies); 2 = moderate growth; 3 = extensive but scattered growth; and 4 = growth consuming the entire plate. Demographic data were assessed using descriptive statistics. Additionally, the Student's t and Wilcoxon signed-rank tests were used to detect differences in categorical bacterial growth between paired samples. A p value of 0.05 represented statistical significance. Kappa statistics of reliability were performed to evaluate interobserver agreement of microorganism growth in the culture plates.

RESULTS

Bacteria were present in 19 of 21 (90%) sets of loupes. Five species of bacteria were noted. Fungi were present in 10 of 21 (48%) sets of loupes. Bacterial contamination was identified in two storage cases (40%) and fungi were present in five cases (100%). In a subset of nine loupes tested, the degree of bacterial presence had a median of 2 (range, 1-4; 95% confidence interval [CI], 1.0-2.6) in samples collected before starting the surgical day compared with 3 (range, 2-4; 95% CI, 2.0-3.3) at the end of the day (p = 0.004). In a separate study arm comprised of six loupes, 1 minute after being cleaned with an alcohol swab, bacterial presence on loupes decreased from a median of 2 (range, 2-3; 95% CI, 1.9-2.5) to a median of 1 (range, 0-2; 95% CI, 0.5-1.5; p = 0.012).

CONCLUSIONS

Loupes are a common reservoir for bacteria and fungi. Given the use of loupes directly over the surgical field and the lack of a barrier, care should be taken to decrease the bacterial load by cleaning loupes and airing out storage cases, which may decrease the risk of surgical field contamination and iatrogenic wound infections.

CLINICAL RELEVANCE

Routine cleaning and disinfecting of optical loupes with alcohol pads can reduce microorganism colonization and should be implemented by surgeons who regularly use loupes in the operating room. Theoretically, particulate shedding from the loupes into the surgical field containing microorganisms could increase the risk of SSI, although this has not been proven clinically.

Low-cost antimicrobial fortification of ultrasound coupling gel: An ergonomic innovation to combat sonology-acquired nosocomial infections

Background

Recent outbreaks of highly contagious diseases have prompted hospital departments to adopt preventive hygiene protocols. Use of shared equipment, including ultrasound transducers and coupling gels, potentially exposes patients to these microbes. Inexpensive means of microbicide fortification of plain/non-sterile ultrasound gel may be useful in interrupting nosocomial infections. The purpose of this study was to evaluate the effectiveness of low-cost antimicrobial fortification of ultrasound coupling gel in preventing nosocomial infections during ultrasound examinations.

Methods

Volunteer patients, 20 in number, who presented for an ultrasound scan in a busy radiology clinic in Enugu, Nigeria, were randomly divided into 2 groups of 10 each and were scanned using plain non-sterile gel and gel-fortified with 0.5% chlorhexidine and 70% ethyl alcohol (in a volume ratio of 20:2:1) respectively. Swabs were taken from the patients' skin, gel-laden transducer, and the cleaned transducer and subjected to microbiology analysis. Subsequently, plain and fortified gel samples were allowed to stand in their respective dispensers for 72 hours. The plain and fortified gel samples were subjected to microbiology analysis. Fisher's Exact Test was utilised to compare outcomes in the 2 groups of volunteers.

Results

With fortified gel, swab cultures from patients' skin and gel-laden transducer, and from the cleaned transducer, significantly yielded no growth (P= <0.0001 and P= 0.0001 respectively) while swab cultures from the plain gel yielded a total of 19 microbial isolates from 5 micro-organisms.

Conclusion

Low-cost fortification of ultrasound coupling gel with 0.5% chlorhexidine and 70% ethyl alcohol renders it hostile to microorganisms encountered at sonology thus preventing nosocomial transmission.

Anesthesia in patients with infectious disease caused by multi-drug resistant bacteria

PURPOSE OF REVIEW

Up to 50% of specific bacterial strains in healthcare admission facilities are multi-drug resistant organisms (MDROs). Involvement of anesthesiologists in management of patients carrying/at risk of carrying MDROs may decrease transmission in the Operating Room (OR).

RECENT FINDINGS

Anesthesiologists, their work area and tools have all been implicated in MDRO outbreaks. Causes include contamination of external ventilation circuits and noncontribution of filters to prevention, inappropriate decontamination procedures for nondisposable equipment (e.g. laryngoscopes, bronchoscopes and stethoscopes) and the anesthesia workplace (e.g. external surfaces of cart and anesthesia machine, telephones and computer keyboards) during OR cleaning and lack of training in sterile drug management.

SUMMARY

Discussions regarding the management of potential MDRO carriers must include anesthesia providers to optimize infection control interventions as well as the anesthesia method, the location of surgery and recovery and the details of patient transport. Anesthesia staff must learn to identify patients at risk for MDRO infection. Antibiotic prophylaxis, although not evidence based, should adhere to known best practices. Adjuvant therapies (e.g. intranasal Mupirocin and bathing with antiseptics) should be considered. Addition of nonmanual OR cleaning methods such as ultraviolet irradiation or gaseous decontamination is encouraged. Anesthesiologists must undergo formal training in sterile drug preparation and administration.