Evaluation of Incise Drape Lift Using 2% Chlorhexidine Gluconate/70% Isopropyl Alcohol Preoperative Skin Preparations in a Human Volunteer Knee Model.

Background: Before surgery, skin is prepped with antiseptics to reduce risk of surgical site infections. An incise drape can be used as an additional modality to immobilize any remaining bacteria. Good adhesion of this drape is critical for infection prevention. Methods: This is a randomized controlled study using a human volunteer knee model (n = 30) to evaluate the adhesion performance of an incise drape comparing 2 skin preparations. A new investigational 2% chlorhexidine gluconate/70% isopropyl alcohol skin prep (prep A) was compared with an existing skin prep containing the same active agents (prep B). Two samples of an iodine-impregnated incise drape were placed on each knee after prepping. Knees were flexed in dry conditions, under a saline-soaked gauze, and after saline lavage. The frequency of drape lift was recorded after each challenge. Results: After dry flex, 4 of 60 samples (6.7%) had lifted on prep A and 0 on prep B (P = .125). After wet flex, 20 of 60 samples (33%) had lifted on prep A, whereas 42 of 60 samples (70%) had lifted on prep B (P < .0001). After lavage, 23 of 60 samples (38%) had lifted on prep A, whereas 48 of 60 samples (80%) had lifted on prep B (P < .0001). Both preps were well tolerated with minimal erythema and no edema, rash, dryness, or denudation observed. No adverse events were reported. Conclusions: Prep A resulted in reduced frequency of incise drape lift from skin under wet conditions in this model compared with prep B.

Zero-heat-flux core temperature monitoring system: an observational secondary analysis to evaluate agreement with naso-/oropharyngeal probe during anesthesia.

General anesthesia impairs thermoregulation and contributes to perioperative hypothermia; core body temperature monitoring is recommended during surgical procedures lasting > 30 min. Zero-heat-flux core body temperature measurement systems enable continuous non-invasive perioperative monitoring. During a previous trial evaluating the benefits of preoperative forced-air warming, intraoperative temperatures were measured with both a zero-heat-flux sensor and a standard naso-/oropharyngeal temperature probe. The aim of this secondary analysis is to evaluate their agreement. ASA I-III patients, scheduled for elective, non-cardiac surgery under general anesthesia, were enrolled. A zero-heat-flux sensor was placed on the participant's forehead preoperatively. Following induction of anesthesia, a "clinical" temperature probe was placed in the nasopharynx or oropharynx at the anesthesiologist's discretion. Temperature measurements from both sensors were recorded every 10 s. Agreement was analyzed using the Bland-Altman method, corrected for repeated measurements, and Lin's concordance correlation coefficient, and compared with existing studies. Data were collected in 194 patients with a median (interquartile range) age of 60 (49-69) years, during surgical procedures lasting 120 (89-185) min. The zero-heat-flux measurements had a mean bias of - 0.05 °C (zero-heat-flux lower) with 95% limits of agreement within - 0.68 to + 0.58 °C. Lin's concordance correlation coefficient was 0.823. The zero-heat-flux sensor demonstrated moderate agreement with the naso-/oropharyngeal temperature probe, which was not fully within the generally accepted ± 0.5 °C limit. This is consistent with previous studies. The zero-heat-flux system offers clinical utility for non-invasive and continuous core body temperature monitoring throughout the perioperative period using a single sensor.

A Comparison of Electronic and Traditional Stethoscopes in the Heart Auscultation of Obese Patients.

Background and objectives: As the prevalence of obesity is increasing in a population, diagnostics becomes more problematic. Our aim was to compare the 3M Littmann 3200 Electronic Stethoscope and 3M Littman Cardiology III Mechanical Stethoscope in the auscultation of obese patients. Methods. A total of 30 patients with body mass index >30 kg/m² were auscultated by a cardiologist and a resident physician: 15 patients by one cardiologist and one resident and 15 patients by another cardiologist and resident using both stethoscopes. In total, 960 auscultation data points were verified by an echocardiogram. Sensitivity and specificity data were calculated. Results. Sensitivity for regurgitation with valves combined was higher when the electronic stethoscope was used by the cardiologist (60.0% vs. 40.9%, p = 0.0002) and the resident physician (62.1% vs. 51.5%, p = 0.016); this was also the same when stenoses were added (59.4% vs. 40.6%, p = 0.0002, and 60.9% vs. 50.7%, p = 0.016, respectively). For any lesion, there were no significant differences in specificity between the electronic and acoustic stethoscopes for the cardiologist (92.4% vs. 94.2%) and the resident physician (93.6% vs. 94.7%). The detailed analysis by valve showed one significant difference in regurgitation at the mitral valve for the cardiologist (80.0% vs. 56.0%, p = 0.031). No significant difference in specificity between the stethoscopes was found when all lesions, valves and both physicians were combined (93.0% vs. 94.4%, p = 0.30), but the electronic stethoscope had higher sensitivity than the acoustic (60.1% vs. 45.7%, p < 0.0001). The analysis when severity of the abnormality was considered confirmed these results. Conclusions. There is an indication of increased sensitivity using the electronic stethoscope. Specificity was high using the electronic and acoustic stethoscope.

Effect of preoperative warming on intraoperative hypothermia: a randomized-controlled trial.

PURPOSE: The purpose of this study was to evaluate the effects of preoperative forced-air warming on intraoperative hypothermia. METHODS: In this randomized-controlled trial, adult patients scheduled for elective, non-cardiac surgery under general anesthesia were stratified by scheduled surgical duration (< 2.5 hr or ≥ 2.5 hr) and then randomized to a pre-warming group using a BairPaws™ forced-air warming system for at least 30 min preoperatively or to a control group with warmed blankets on request. All patients were warmed intraoperatively via convective forced-air warming blankets. Perioperative temperature was measured using the SpotOn™ temperature system consisting of a single-use disposable sensor applied to the participant's forehead. The primary outcome was the magnitude of intraoperative hypothermia calculated as the area under the time-temperature curve for core temperatures < 36°C between induction of general anesthesia and leaving the operating room. Secondary outcomes included surgical site infections, packed red blood cell requirements, and 24 hr postoperative opioid consumption. RESULTS: Two hundred participants were analyzed (101 control; 99 pre-warmed). Pre-warmed participants had a lower median [interquartile range] magnitude of hypothermia than controls (0.00 [0.00-0.12] °C·hr-1 vs 0.05 [0.00-0.36] °C·hr-1, respectively; median difference, -0.01°C·hr-1; 95% confidence interval, -0.04 to 0.00°C·hr-1; P = 0.005). There were no between-group differences in the secondary outcomes. CONCLUSION: A minimum of 30 min of preoperative forced-air convective warming decreased the overall intraoperative hypothermic exposure. While redistribution hypothermia still occurs despite pre- and intraoperative forced-air warming, their combined application results in greater preservation of intraoperative normothermia compared with intraoperative forced-air warming alone. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02177903). Registered 25 June 2014.

How to better monitor and clean irregular surfaces in operating rooms: Insights gained by using both ATP luminescence and RODAC assays.

BACKGROUND: A major limitation to developing evidence-based approaches to infection prevention is the paucity of real-time, quantitative methods for monitoring the cleanliness of environmental surfaces in clinical settings. One solution that has been proposed is adenosine triphosphate (ATP) bioluminescence assays, but this method does not provide information about the source of the ATP. MATERIALS/METHODS: To address this gap, we conducted a study in which ATP bioluminescence was coupled with traditional RODAC sampling and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry to assess which organisms were viable and present. Using this mixed assessment approach, we evaluated cleaning of 5 different types of high-touch surfaces (overhead lights, door handles, anesthesia keyboards, mattresses, and side tables) in operating rooms. RESULTS: Whether surfaces tested cleaner after turnaround than they did before turnaround depended on the surface type. Before and after cleaning, flat, covered surfaces (mattresses and side tables) were more likely to pass as "clean" by ATP assay than uncovered, irregularly shaped surfaces (overhead lights, door handles, and anesthesia keyboards). Irregularly shaped surfaces were more likely to pass by RODAC assay than by ATP assay after cleaning. CONCLUSION: Our results suggest that irregularly shaped surfaces in operating rooms may require enhanced covering, cleaning, and monitoring protocols compared to more regularly shaped surfaces.

Efficacy of skin and nasal povidone-iodine preparation against mupirocin-resistant methicillin-resistant Staphylococcus aureus and S. aureus within the anterior nares.

Mupirocin decolonization of nasal Staphylococcus aureus prior to surgery decreases surgical-site infections; however, treatment requires 5 days, compliance is low, and resistance occurs. In 2010, 3M Company introduced povidone-iodine (PVP-I)-based skin and nasal antiseptic (Skin and Nasal Prep [SNP]). SNP has rapid, broad-spectrum antimicrobial activity. We tested SNP's efficacy using full-thickness tissue (porcine mucosal [PM] and human skin) explant models and human subjects. Prior to or following infection with methicillin-resistant Staphylococcus aureus (MRSA) (mupirocin sensitive and resistant), explants were treated with Betadine ophthalmic preparation (Bet), SNP, or mupirocin (Bactroban nasal ointment [BN]) or left untreated. One hour posttreatment, explants were washed with phosphate-buffered saline (PBS) plus 2% mucin. One, 6, or 12 h later, bacteria were recovered and enumerated. Alternatively, following baseline sampling, human subjects applied two consecutive applications of SNP or saline to their anterior nares. One, 6, and 12 h after application of the preparation (postprep), nasal swabs were obtained, and S. aureus was enumerated. We observed that treatment of infected PM or human skin explants with SNP resulted in >2.0 log10 CFU reduction in MRSA, regardless of mupirocin sensitivity, which was significantly different from the values for BN- and Bet-treated explants and untreated controls 1 h, 6 h, and 12 h after being washed with PBS plus mucin. Swabbing the anterior nares of human subjects with SNP significantly reduced resident S. aureus compared to saline 1, 6, and 12 h postprep. Finally, pretreatment of PM explants with SNP, followed by a mucin rinse prior to infection, completely prevented MRSA infection. We conclude that SNP may be an attractive alternative for reducing the bioburden of anterior nares prior to surgery.

Prospective, randomized in vivo comparison of a dual-active waterless antiseptic versus two alcohol-only waterless antiseptics for surgical hand antisepsis.

BACKGROUND: This study aimed to demonstrate the value of adding an active level of a persistent antimicrobial agent, such as chlorhexidine gluconate (CHG), to an alcohol-based surgical hand antiseptic. METHODS: The persistence of 3 waterless, brushless alcohol-based surgical hand antiseptics, including one product containing CHG, was compared. The test products were applied a total of 12 times over 5 days. Samples of aerobic bacteria were collected on days 1 and 5, on both days immediately after drying and 6 hours later, using the glove juice technique. Relative suppression of regrowth was compared using t tests. RESULTS: Using an equivalence margin of 20%, the alcohol plus CHG product showed noninferiority to the alcohol-only products at all sampling points and, based on significantly lower bacterial regrowth (P = .026), superior persistence to the alcohol-only products after 6 hours of glove wear. CONCLUSIONS: Given the primary objective of surgical hand antisepsis of reducing resident skin flora for the duration of the surgical procedure, using an alcohol-based hand antiseptic containing CHG appears to be the most appropriate choice for maintaining microbial levels as low as possible for as long as possible.

Methicillin-resistant Staphylococcus aureus colonization at different body sites: a prospective, quantitative analysis.

We quantified methicillin-resistant Staphylococcus aureus (MRSA) carriage. The greater the log(10) count in samples from the nares, the greater the likelihood that other body sites had been colonized. Log(10) counts among body sites were correlated. The greatest sensitivity value (98%) was determined for the combined results from 2 sites: the nares and the groin.

Resistance of antimicrobial skin preparations to saline rinse using a seeded bacteria model.

OBJECTIVE: We describe a randomized blinded study to evaluate the antimicrobial persistence following saline exposure of 2 commercially available skin antiseptic agents. One agent contained iodine povacrylex in alcohol and the second contained chlorhexidine gluconate in alcohol. METHOD: Both agents were applied to the forearms of 36 healthy subjects according to manufacturers' instructions and allowed to dry. The sites were then exposed to either a saline rinse or to a saline-saturated gauze, similar to the challenges that preps would face during most surgical procedures. Two analyses were performed: (1) An indicator organism was seeded onto the treated sites. After 30 minutes, samples were collected from the treated sites and surviving bacterial colonies were enumerated and log reductions calculated. (2) The saline-saturated gauze was analyzed chemically for presence of chlorhexidine or iodine. RESULTS: The baseline densities (stated as logarithms of colony forming units "log CFU") of the sites to which the agents were applied had statistically equivalent microbial densities. Both agents reduced the density of organisms in a statistically significant manner. Chemical analysis of the gauze samples indicated that 35 of 36 samples had detectable chlorhexidine while no samples had detectable iodine (P < .0001). CONCLUSION: The results indicate that chlorhexidine is removed by saline-soaked gauze while the iodine povacrylex water-insoluble film remains intact under the same conditions. The implication is that similar results may occur in surgery when saline is used.