The relative efficacy of multiple syringe tip disinfection techniques against virulent staphylococcus contamination.

BACKGROUND: A recent study confirmed significant contamination of syringe tips following routine anaesthesia practice of at least 6 h in duration. AIM: We assessed the relative efficacy of clinically relevant syringe tip disinfection techniques following contamination with the hyper transmissible and more pathogenic Staphylococcus aureus sequence type 5 (S. aureus ST5) strain characteristic associated with increased strength of biofilm formation and greater desiccation tolerance. METHODS: Syringe tips (N=40) contaminated with S. aureus ST5 were randomized to 70% isopropyl pads with 10 or 60 s of drying time, scrubbing alcohol disinfection caps with 10 or 60 s of dwell time, or to non-scrubbing alcohol disinfection caps with 60 s of dwell time. The primary outcome was residual 24-h colony forming units (cfu) >10. RESULTS: Scrubbing disinfection caps were more effective than alcohol pads (25% (12/48) <10 cfu for scrubbing caps (10- or 60-s dwell times) vs 0% (0/48) <10 cfu for alcohol pads (10 or 60 s of drying time), Holm-Sidak adjusted P=0.0016). Scrubbing disinfection caps were more effective than non-scrubbing alcohol disinfection caps (25% (12/48) <10 cfu for scrubbing alcohol caps (10- or 60-s dwell times) vs 2% (1/48) for non-scrubbing alcohol caps (60-s dwell time), adjusted P=0.0087). CONCLUSIONS: Scrubbing alcohol caps are more effective than alcohol pads or non-scrubbing disinfecting caps for microbial reduction of syringe tips contaminated with the more pathogenic S. aureus ST5.

Characterizing the molecular epidemiology of anaesthesia work area transmission of Staphylococcus aureus sequence type 5.

BACKGROUND: Staphylococcus aureus sequence type 5 (ST5) is an emerging global threat. AIM: To characterize the epidemiology of ST5 transmission in the anaesthesia work area. METHODS: The retrospective cohort study analysed transmitted, prophylactic antibiotic-resistant Staphylococcus aureus isolates involving anaesthesia work area reservoirs. Using whole-genome analysis, the epidemiology of ST5 transmission was characterized by reservoir(s) of origin, transmission location(s), portal of entry, and mode(s) of transmission. All patients were followed for at least 30 days for surgical site infection (SSI) development. FINDINGS: Forty-one percent (18/44; 95% confidence interval: 28-56%) of isolates were ST5. Provider hands were the reservoir of origin for 28% (5/18) of transmitted ST5 vs 4% (1/26) for other STs. Provider hands were the transmission location for 28% (5/18) of ST5 vs 7% (2/26) of other STs. Stopcock contamination occurred for 8% (1/13) of ST5 isolates vs 12% (3/25) of other STs. Sixty-three percent of transmission events occurring between cases on separate operative dates involved ST5. ST5 was more likely to harbour resistance traits (ST5 median (interquartile range) 3 (2-3) vs 2 (1-2) other STs; P < 0.001) and had greater resistance to cefazolin, piperacillin-tazobactam, and/or ciprofloxacin (ST5: 3 (2-3) vs 2 (1-3) other STs; P = 0.02). ST5 was associated with three of six SSIs. CONCLUSION: ST5 is prevalent among transmitted, prophylactic antibiotic-resistant isolates in the anaesthesia work area. Transmission involves provider hands and one patient to another on future date(s). ST5 is associated with a greater number of resistance traits and reduced in-vitro susceptibility vs other intraoperative meticillin-resistant S. aureus.

Transmission of Staphylococcus aureus in the anaesthesia work area has greater risk of association with development of surgical site infection when resistant to the prophylactic antibiotic administered for surgery.

BACKGROUND: The extent to which the transmission of prophylactic-antibiotic-resistant bacteria from the anaesthesia work area increases the risk of surgical site infection (SSI) is unknown. It was hypothesized that the risk of SSI would increase progressively from no transmission to transmission of prophylactic-antibiotic-resistant isolates. METHODS: This was a retrospective analysis of archival samples collected in two previously published studies with similar inclusion criteria and sample collection methodology (observational study 2009-2010 and randomized trial 2018-2019). Archival isolates were linked by barcode to all patient demographic and procedural information, including the prophylactic antibiotic administered, transmission and development of SSI. For this study, all archival isolates underwent prophylactic antibiotic susceptibility testing, and the ordered association of transmission of Staphylococcus aureus (no transmission, transmission of prophylactic-antibiotic-susceptible isolates and transmission of prophylactic-antibiotic-resistant isolates) with SSI was assessed. RESULTS: The risk of development of SSI was 2% (8/406) without S. aureus transmission, 11% (9/84) with transmission of S. aureus isolates that were susceptible to the prophylactic antibiotic used, and 18% (4/22) with transmission of prophylactic-antibiotic-resistant S. aureus isolates. The Cochrane-Armitage two-sided test for ordered association was P<0.0001. Treating these three groups as 0, 1 and 2, by exact logistic regression, the odds of SSI increased by 3.59 with each unit increase (95% confidence interval 1.92-6.64; P<0.0001). CONCLUSIONS: Transmission of S. aureus in the anaesthesia work area reliably increases the risk of SSI, especially when the isolates are resistant to the prophylactic antibiotic administered.

Desiccation tolerance is associated with Staphylococcus aureus hypertransmissibility, resistance and infection development in the operating room.

BACKGROUND: Desiccation tolerance increases Staphylococcus aureus survival and risk of transmission. A better understanding of factors driving intraoperative transmission of S. aureus pathogens may lead to innovative improvements in intraoperative infection control. AIMS: To determine whether desiccation tolerance is associated with intraoperative S. aureus transmission, and to examine typical transmission dynamics for desiccation-tolerant isolates in the operating room in order to provide the impetus for development of improved intraoperative infection control strategies. METHODS: S. aureus isolates (N=173) were collected from anaesthesia work area reservoirs in 274 operating room environments. Desiccation tolerance was assessed and the potential association with sequence type (ST) and clonal transmission was evaluated. Whole cell genome analysis and pulsed-field gel electrophoresis analysis were used to compare desiccation-tolerant isolates with causative organisms of infection. FINDINGS: S. aureus ST 5 isolates had greater desiccation tolerance than all other intraoperative STs [ST 5, N=34, median Day 2 colony-forming unit (cfu) survival 0.027% ± 0.029%; other STs, N=139, median Day 2 cfu survival 0.0091% ± 1.41%; corrected P=0.0001]. ST 5 was associated with increased risk of clonal transmission (relative risk 1.82, 95% confidence interval 1.23-2.71, P=0.003). ST 5 transmission was linked by whole cell genome analysis to postoperative infection. CONCLUSIONS: Increased desiccation tolerance is associated with intraoperative transmission of S. aureus ST 5 isolates that are linked to postoperative infection. Future work should determine whether attenuation of desiccation-tolerant, intraoperative ST 5 strains can impact the incidence of healthcare-associated infections.

Hypotension during induction of anaesthesia is neither a reliable nor a useful quality measure for comparison of anaesthetists' performance.

BACKGROUND: Identification of statistically reliable outcomes for comparison among anaesthetists is challenging. Time-weighted intraoperative mean arterial pressure <65 mm Hg (AUC 65 ) is associated with increased odds for myocardial damage. We explored retrospectively whether such hypotension before incision was statistically reliable for peer comparison. METHODS: We retrieved electronic data between 2006 and 2015 at a tertiary care, academic hospital in the USA for patients at risk for myocardial damage (inpatient after surgery, ASA physical status ≥III, ≥50 yr of age, and case duration ≥60 min). We determined the percentage of anaesthetists comparable based on caseload and case-mix. The AUC 65 was compared amongst anaesthetists supervising ≥100 cases involving at-risk patients during the last 12 months. RESULTS: Only 14.1% [95% confidence interval (CI) 13.6-14.5%] of cases involved patients who were 'at risk' during the 10 yr study period. A yearly average of 49 ( sd 6) anaesthetists supervised ≥100 cases of any type, of whom only 52% (95% CI 47.1-56.0%) supervised ≥100 cases involving at-risk patients. Thus, nearly half the anaesthetists would have been excluded from peer comparison. During the last 12 months, there were two outliers among 34 evaluable anaesthetists ( P <0.05, controlling for false discovery). However, their contribution to total hypotension amongst cases for all patients was small, because hypotension was widely distributed (e.g. 80% of hypotension attributable to 61.8% of anaesthetists, 95% CI 59.8-63.7%). There was no relationship between the AUC 65 and propofol induction dose. CONCLUSIONS: The AUC 65 of time-weighted pre-incision hypotension is not a suitable metric for comparing anaesthetists. There were few at-risk patients, half the anaesthetists were not evaluable because of their case-mix and caseload, and hypotension was widely distributed.

Hospitals with briefer than average lengths of stays for common surgical procedures do not have greater odds of either re-admission or use of short-term care facilities.

We considered whether senior hospital managers and department chairs need to be concerned that small reductions in average hospital length of stay (LOS) may be associated with greater rates of re-admission, use of home health care, and/or transfers to short-term care facilities. The 2013 United States Nationwide Readmissions Database was used to study surgical Diagnosis Related Groups (DRG) with 1) national median LOS ≥3 days and 2) ≥10 hospitals in the database that each had ≥100 discharges for the DRG. Dependent variables were considered individually: 1) re-admission within 30 days of discharge, 2) discharge disposition to home health care, and/or 3) discharge disposition of transfer to short-term care facility (i.e., inpatient rehabilitation hospital or skilled nursing facility). While controlling for DRG, each one-day decrease in hospital median LOS was associated with an odds of re-admission nationwide of 0.95 (95% confidence interval [CI] 0.92-0.99; P=0.012), odds of disposition upon discharge being home care of 0.95 (95% CI 0.83-1.10; P=0.64), and odds of transfer to short-term care facility of 0.68 (95% CI 0.54-0.85; P=0.0008). Results were insensitive to the addition of patient-specific data. In the USA, patients at hospitals with briefer median LOS across multiple common surgical procedures did not have a greater risk for either hospital re-admission within 30 days of discharge or transfer to an inpatient rehabilitation hospital or a skilled nursing facility. The generalisable implication is that, across many surgical procedures, DRG-based financial incentives to shorten hospital stays seem not to influence post-acute care decisions.

Calculating the probability of random sampling for continuous variables in submitted or published randomised controlled trials.

In a previous paper, one of the authors (JBC) used a chi-squared method to analyse the means (SD) of baseline variables, such as height or weight, from randomised controlled trials by Fujii et al., concluding that the probabilities that the reported distributions arose by chance were infinitesimally small. Subsequent testing of that chi-squared method, using simulation, suggested that the method was incorrect. This paper corrects the chi-squared method and tests its performance and the performance of Monte Carlo simulations and ANOVA to analyse the probability of random sampling. The corrected chi-squared method and ANOVA method became inaccurate when applied to means that were reported imprecisely. Monte Carlo simulations confirmed that baseline data from 158 randomised controlled trials by Fujii et al. were different to those from 329 trials published by other authors and that the distribution of Fujii et al.'s data were different to the expected distribution, both p < 10(-16) . The number of Fujii randomised controlled trials with unlikely distributions was less with Monte Carlo simulation than with the 2012 chi-squared method: 102 vs 117 trials with p < 0.05; 60 vs 86 for p < 0.01; 30 vs 56 for p < 0.001; and 12 vs 24 for p < 0.00001, respectively. The Monte Carlo analysis nevertheless confirmed the original conclusion that the distribution of the data presented by Fujii et al. was extremely unlikely to have arisen from observed data. The Monte Carlo analysis may be an appropriate screening tool to check for non-random (i.e. unreliable) data in randomised controlled trials submitted to journals.

Mediated interruptions of anaesthesia providers using predictions of workload from anaesthesia information management system data.

Perioperative interruptions generated electronically from anaesthesia information management systems (AIMS) can provide useful feedback, but may adversely affect task performance if distractions occur at inopportune moments. Ideally such interruptions would occur only at times when their impact would be minimal. In this study of AIMS data, we evaluated the times of comments, drugs, fluids and periodic assessments (e.g. electrocardiogram diagnosis and train-of-four) to develop recommendations for the timing of interruptions during the intraoperative period. The 39,707 cases studied were divided into intervals between: 1) enter operating room; 2) induction; 3) intubation; 4) surgical incision; and 5) end surgery. Five-minute intervals of no documentation were determined for each case. The offsets from the start of each interval when >50% of ongoing cases had completed initial documentation were calculated (MIN50). The primary endpoint for each interval was the percentage of all cases still ongoing at MIN50. Results were that the intervals from entering the operating room to induction and from induction to intubation were unsuitable for interruptions confirming prior observational studies of anaesthesia workload. At least 13 minutes after surgical incision was the most suitable time for interruptions with 92% of cases still ongoing. Timing was minimally affected by the type of anaesthesia, surgical facility, surgical service, prone positioning or scheduled case duration. The implication of our results is that for mediated interruptions, waiting at least 13 minutes after the start of surgery is appropriate. Although we used AIMS data, operating room information system data is also suitable.

Observational study of anaesthetists' fresh gas flow rates during anaesthesia with desflurane, isoflurane and sevoflurane.

Reducing excessive fresh gas flow rates (FGF) is an established and simple strategy to reduce the administration of volatile anaesthetic agents. We studied clinicians' FGF use to understand better why two previous clinical trials achieved significant reductions in FGF by using feedback to anaesthetists. Anaesthesia information management system data from a US academic medical centre were analysed retrospectively. One year of data starting from July 2008 had 11,170 cases. Fresh gas flow rates were measured each minute during cases. Anaesthetists were more likely to choose FGF of multiples of 1 l/minute and 0.5 l/minute than random. However the pattern was too inconsistent to be of economic or psychological importance and thus is not needed when describing a target FGF. Cumulative distributions of FGF were shifted to the left for desflurane and isoflurane compared to sevoflurane (i.e. cost comparisons among agents may need to use different target FGF). Variation in mean FGF among anaesthetists was small. Even if all anaesthetists had identical mean FGF, the standard deviation of FGF among cases would be reduced by less than 0.1 l/minute for all agents. Most of the achievable reductions in FGF were small reductions in FGF for the many cases with < 3 l/minute. These results show that departments choosing to use inexpensive automatic email feedback on FGF should target all anaesthetists and focus on variation in FGF among anaesthetists' cases.

[Allocating and scheduling operating room time]. / Zuweisung und Planung von Operationsraumkapazitäten Maximierung der Operationsraumeffizienz am Beispiel einer deutschen Universitätsklinik.

During the past decade many scientific advances have been made concerning the development of methodologies to maximize efficiency of surgical facilities through allocating and scheduling of operating rooms. In this article such a methodology is described. Using the analysis of historical data of surgical activity in a facility, future demand is predicted and planned. Part of the methodology includes principles and rules needed for the daily organization and operative management of surgical facilities. They are also derived from the same science and therefore the basis for rational and structured decision making. Medical aspects such as patient safety and free choice of day for surgery have higher priority than the economic goal of maximizing operating room efficiency.

Brain expression of inducible cyclooxygenase 2 messenger RNA in rats undergoing cardiopulmonary bypass.

BACKGROUND: We hypothesized that systemic proinflammatory cytokines or endotoxemia, or both, associated with cardiopulmonary bypass (CPB) would increase expression of inducible cyclooxygenase (COX-2) or inducible nitric oxide synthase (iNOS) messenger RNA (mRNA), or both, in brain. METHODS: Isoflurane-anesthetized Sprague-Dawley rats were randomly selected for CPB (n = 6) or sham surgery (n = 6). All animals underwent tracheotomy and controlled ventilation, arterial and venous pressure monitoring, insertion of a jugular venous outflow catheter, insertion of a subclavian arterial inflow catheter, systemic anticoagulation (500 U/kg heparin) and, except during CPB, servoregulation of pericranial temperature at 37.5 degrees C. Animals selected for CPB underwent 1 h of CPB at 165 ml x kg(-1) x min(-1) (31.8 +/- 0.2 degrees C), whereas animals having sham surgery underwent no intervention during this interval. Thereafter, all animals were given protamine and remained anesthetized for 4 more h. Brain and liver COX-2 and iNOS mRNA expression were determined by a ribonuclease protection assay with ribosomal L32 mRNA as a loading control. Arterial blood was analyzed for interleukin 1beta, interleukin 6, and endotoxin concentrations. RESULTS: Endotoxin concentrations did not increase above baseline values in either group. At 4 h after the CPB interval, interleukin 6 concentrations were significantly greater in CPB animals (101 +/- 45 pg/ml) versus sham animals (44 +/- 17 pg/ml) (P = 0.025). Brain COX-2 expression was significantly greater in CPB animals (0.36 +/- 0.11) versus shams (0.19 +/- 0.08) (P = 0.013). Brain COX-2 expression correlated with interleukin 6 concentration 4 h after CPB (r = 0.91; P = 5 x 10(-5)). In brain, iNOS mRNA was not detected in any animal. Cardiopulmonary bypass animals had only trace COX-2 and iNOS mRNA induction in liver. CONCLUSIONS: Cardiopulmonary bypass was associated with increased systemic interleukin 6 concentrations and increased brain COX-2 expression.

Weekend operating room on call staffing requirements.

This article describes a statistical method used to determine the minimum number of OR teams that should be on call for urgent procedures, in-house versus on standby from home, to minimize labor costs. The OR manager obtains the number of ORs staffed at each hour of the 24-hour period of interest (e.g., 7 AM Saturday to 7 AM Sunday) from the surgical suite's information system. The minimum number of total staffed hours needed to care for patients is calculated for a prespecified level of the acceptable risk of inadequate staffing. A method used to determine whether each staff member should work in-house or on standby from home then is introduced. This method enumerates all possible combinations of shifts to find the one with the lowest cost, and it ensures a prespecified service level. An example based on 248 weeks of data collected from a large surgical suite is presented, and staffing for emergency procedures is reviewed.

Reducing family members' anxiety while waiting on the day of surgery: systematic review of studies and implications of HIPAA health information privacy rules.

STUDY OBJECTIVE: To investigate changes that most surgical suites will need to make in the process of giving reports to family members on the day of surgery by the compliance date (April 14, 2003) of the privacy regulations of the Health Insurance Portability and Accountability Act (HIPPA) of 1996. DESIGN: Systematic review of the medical literature on ways in which providing information to family members changes their anxiety. MEASUREMENTS: The endpoints of the controlled studies included Spielberger State Anxiety. The observational studies reported percentages of family members with a specific concern. MAIN RESULTS: An in-person progress report can reduce family members' anxiety, but this is not always. A personal approach is superior to providing pagers or a phone call. Observational studies suggest that family members want information specific to their relative, particularly if the case is running later than expected. Statistical methods exist to provide such an estimate of the time remaining in surgical cases. CONCLUSIONS: Surgical facilities should strive to provide in-person progress reports to family members while their relatives are undergoing surgery. To satisfy HIPAA regulations, the staff and physicians who talk to family members in the waiting room will need to determine first if the patient has agreed to the release of information. As hospital information systems are updated to assure that this process is HIPAA-compliant, facilities can also incorporate the relevant statistical methods.