Inter-strain comparison by pyrolysis mass spectrometry in the investigation of Staphylococcus aureus nosocomial infection.

Pyrolysis mass spectrometry (PyMS) was used to examine isolates of Staphylococcus aureus from an outbreak of wound infections on a cardiothoracic surgical unit, some of which were thought to have been related to a point-source in the operating theatre. The PyMS results were compared with the results of phage typing. Both methods suggested that a single strain of S. aureus, of phage pattern 29/52/52A/79/80/81, was responsible for some of the wound infections, but PyMS also identified two patients with phage non-typable isolates. Phage typing indicated four staff members as possible carriers of the epidemic strain, but PyMS indicated only two. Epidemiological enquiry confirmed that one of the two members of staff identified by both methods was likely to have been the source of the theatre-based infection. PyMS is a rapid and relatively inexpensive technique for the investigation of nosocomial S. aureus infection and was more discriminatory than phage typing in this instance.     

Severe Streptococcus pyogenes infections, United Kingdom, 2003-2004

As part of a Europe-wide initiative to explore current epidemiologic patterns of severe disease caused by Streptococcus pyogenes, the United Kingdom undertook enhanced population-based surveillance during 2003-2004. A total of 3,775 confirmed cases of severe S. pyogenes infection were identified over 2 years, 3.33/100,000 population, substantially more than previously estimated. Skin/soft tissue infections were the most common manifestation (42%), followed by respiratory tract infections (17%). Injection drug use was identified as a risk factor for 20% of case-patients. One in 5 infected case-patients died within 7 days of diagnosis; the highest mortality rate was for cases of necrotizing fasciitis (34%). Nonsteroidal antiinflammatory drugs, alcoholism, young age, and infection with emm/M3 types were independently associated with increased risk for streptococcal toxic shock syndrome. Understanding the pattern of these diseases and predictors of poor patient outcome will help with identification and assessment of the potential effect of targeted interventions.     

Air bacterial and particle counts in total hip replacement operations using non-woven and cotton gowns and drapes

Air bacterial and particle counts were obtained in a conventionally ventilated operating theatre, during 8 operations for total hip replacement performed using synthetic non-woven fabrics as drapes for the patients and gowns for the staff (trousers and stockings were of conventional cotton material), ('non-woven' group), and in 8 corresponding operations using conventional cotton fabrics ('cotton' group). No significant difference between the groups with regard to air bacterial counts was observed. The use of cotton fabrics was associated with substantially higher particle counts, probably due to particles from the cotton textiles themselves. No significant correlation was observed between the bacterial and particle counts, indicating that these came from different sources and that the particles were mainly of sterile origin. Thus, the benefit of the synthetic, non-woven fabrics in hip replacement surgery, when these fabrics are used to cover theatre staff only partially in the form of gowns, seems questionable with regard to the reduction of air bacterial counts. On the other hand, the surgical textiles of non-woven material improve the purity of the operating theatre since unlike cotton fabrics they do not produce and disperse particles in the air.     

Source of bacterial shedding in laminar flow theatres

In a previous unpublished observation, unacceptably high bacterial counts, presumably due to shedding episodes, occurred in two of 56 (3.57%) slit-air samples during arthroplasty surgery in a laminar flow operating theatre. The isolates matched those cultured from swab samples taken from the skin of one of the surgeons's foreheads on each of the two occasions. These findings occurred despite scrub staff wearing standard occlusive gowns, hats and masks with visors. In order to localize the potential source of such shedding more accurately, 20 members of theatre staff underwent anonymous microbiological swabbing from the facial areas not covered by theatre clothing, namely their foreheads, eyebrows and ears. These swabs were cultured and the growths were compared statistically. Significantly more colonies were cultured from swabs taken from the theatre staff's ears (P = 0.047, Freidman's test) compared with the other two facial areas studied. These data support the use of exhaust helmets in arthroplasty surgery, or at least mandatory coverage of the ears with theatre hats for scrub staff.     

Serotyping of Streptococcus pyogenes isolated from common and severe invasive infections in Japan, 1990-5: implication of the T3 serotype strain-expansion in TSLS. The Working Group for Group A Streptococci in Japan.

To clarify the relationship between the epidemics of severe invasive group A streptococcal infections (streptococcal Toxic Shock-Like Syndrome: TSLS) and common group A streptococcal infections in Japan, we examined the T serotypes of S. pyogenes strains (group A streptococci) isolated from clinical specimens of the streptococcal infections (17999 cases) in the period 1990-5, including the severe infections (TSLS) (29 cases) in the period 1992-5. Characteristic points of the analyses were: (1) dominant serotypes of the infections in these periods were T12, T4, T1, T28 and TB3264, which were consistently isolated; (2) isolates of T3 rapidly increased through 1990 to 1994 while T6 decreased in the period 1990-3; (3) when Japanese area was divided into three parts, T3 serotype tended to spread out from the north-eastern to the south-western area; (4) strains of T3 and T1 serotypes were dominant in the TSLS. Dominant-serotype strains of streptococcal infections did not always induce severe infections and dominance of T3 serotype in the TSLS seemed to be correlated with the increase of T3 in streptococcal infections. These results may indicate that certain clones of S. pyogenes are involved in the pathogenesis of the TSLS.     

Cancellation in elective orthopaedic surgery

The management of operating theatre time is a crucial element in the size of surgical waiting lists, and this paper reports a survey of causes of the cancellation of operations for orthopaedic surgery. The results show that, although the majority of cancellations were due to medical causes, others were the result of extended theatre schedules. These findings suggest that closer co-operation between surgical staff, general practitioners and theatre staff could help to reduce this problem.     

Invasive Streptococcus pyogenes infections in children.

We investigated the epidemiology and clinical features of invasive S. pyogenes infection in a pediatric population over a 7-year period (1984-90) by retrospective review. An increasing frequency in invasive infections had occurred (0-11.81/10,000 admissions). A large proportion (48%) of these were orthopedic infections. An epidemic strain was typed as M1T1. This increase appears to have occurred in the context of an overall increase in S. pyogenes infections ("scarlet fever" 1.47-11.22/10,000 outpatients; "strep throat" 4.41-46.54/10,000 outpatients).     

Theatre gowns: a survey of the extent of user protection

This paper describes a survey of contamination by blood and other body fluids to theatre staff during general and orthopaedic surgery. Fourteen surgeons completed questionnaires following 243 operations, providing information describing the extent of contamination. Recommendations are made for more extensive precautions to be taken when operating on patients considered to be at high-risk of carrying human immunodeficiency virus (HIV). Further assessment of the reliability and comfort of impermeable gowns is required.     

Operating theatres. Funders keepers

Recruiting and retaining operating theatre staff is a constant problem for many trusts. One trust has introduced a pay supplement of 1,500 Pounds for all operating theatre staff, and is now planning to implement a single pay spine for all categories of operating theatre staff. The long-standing staffing difficulties suggest it is time to reconsider skill mix in operating theatres.     

An outbreak of Staphylococcus aureus in a pediatric cardiothoracic surgery unit.

OBJECTIVE: To investigate an outbreak of Staphylococcus aureus surgical-site infections. DESIGN: Case-control study. SETTING: Pediatric cardiothoracic surgery service of a tertiary-care university medical center. METHOD: Molecular typing was used to identify healthcare workers who carried the epidemic strain. RESULTS: Three children acquired surgical-site infections caused by a single strain of S. aureus. Fourteen (25%) of the staff members in the operating room and 17 (11%) on nursing units carried the epidemic strain (P = .01). A case-control study identified 4 healthcare workers who were associated statistically with the outbreak, 2 of whom (a cardiothoracic surgeon and a perfusionist) carried the epidemic strain in their nares. The surgeon also carried the epidemic strain on his hands. Each staff member who carried the epidemic strain was treated with mupirocin; those carrying the strain on their hands were required to wash their hands with chlorhexidine. The surgeon was not allowed to perform surgery until 2 of his hand cultures did not grow S. aureus. CONCLUSIONS: Only three children were infected with the epidemic strain, but it was disseminated widely among staff who cared for children who underwent cardiothoracic surgery. No additional cases were identified after staff members who carried the epidemic strain were decolonized. Both classic epidemiologic methods and molecular typing techniques were necessary to identify the source and extent of this outbreak.     

Active warming systems to maintain perioperative normothermia in hip replacement surgery: a therapeutic aid or a vector of infection?

Various reliable body heat-regulating systems have been designed and developed with the aim of maintaining an adequate body temperature in the course of major surgery. This is crucial to avoid the onset of potentially severe complications that are especially serious in elderly and debilitated subjects. Among these systems, the Bair Hugger blanket has demonstrated excellent efficacy. However, some reports in the literature have suggested that the use of such devices can increase the risk of nosocomial infections, particularly surgical wound infections. The aim of this study was to assess the risk of contamination of the surgical site correlated to the use of the Bair Hugger blanket during hip replacement surgery. To this end, the level of bacterial contamination of the air in the operating theatre was quantified with and without the use of the Bair Hugger, during the course of 30 total non-cemented hip implants performed in patients with osteoarthritis. Sampling was done both in the empty theatre and during surgical procedures, in different zones around the operating table and on the patient's body surface. Statistical analysis of the results demonstrated that the Bair Hugger system does not pose a real risk for nosocomial infections, whereas it does offer the advantage of preventing the potentially very severe consequences of hypothermia during major orthopaedic surgery. In addition, monitoring patients over the six months following the operation allowed us to exclude a later manifestation of a nosocomial infection.     

Balancing operating theatre and bed capacity in a cardiothoracic centre

Cardiothoracic surgery requires many expensive resources. This paper examines the balance between operating theatres and beds in a specialist facility providing elective heart and lung surgery. Without both operating theatre time and an Intensive Care bed a patient’s surgery has to be postponed. While admissions can be managed, there are significant stochastic features, notably the cancellation of theatre procedures and patients’ length of stay on the Intensive Care Unit. A simulation was developed, with clinical and management staff, to explore the interdependencies of resource availabilities and the daily demand. The model was used to examine options for expanding the capacity of the whole facility. Ideally the bed and theatre capacity should be well balanced but unmatched increases in either resource can still be beneficial. The study provides an example of a capacity planning problem in which there is uncertainty in the demand for two symbiotic resources.     

Antibiotic resistance of coagulase-negative staphylococci in an orthopaedic department

Coagulase-negative staphylococci (CNS) were cultured from the anterior nares of surgeons, theatre and ward staff, and from patients before and 2 weeks after a total hip replacement. The CNS found in ward staff were more resistant to antibiotics than those in surgeons and theatre staff. Methicillin resistance of CNS in patients increased from 4 to 31% following surgery. Gentamicin-resistant CNS were only found postoperatively, in 20% of patients, in most of whom gentamicin-loaded acrylic bone cement was used.     

An outbreak of coagulase-negative staphylococcal surgical-site infections following aortic valve replacement.

OBJECTIVES: To determine the cause of a coagulase-negative staphylococcal outbreak and to identify risk factors for surgical-site infections among patients following Medtronic Freestyle bioprosthesis implantation. DESIGN: Retrospective case-control study. SETTING: An 800-bed university referral center. PATIENTS: The cohort of 64 patients undergoing Freestyle valve replacement from September 1998 to December 1998. RESULTS: Seven patients developed infection (10.9% vs 1.1% during the preceding 8 months), including two with mediastinitis and five with endocarditis. There were no statistically significant differences between cases and controls with respect to age, gender, weight, underlying illness, preoperative hospital stay, duration of surgery, time on bypass, central venous catheter duration, National Nosocomial Infection Surveillance risk index, New York Heart Association class, albumin, or antibiotic prophylaxis. However, only three cases were documented to have received vancomycin prophylaxis. Of all staff evaluated, only surgical resident A was significantly associated with infection (odds ratio, 7.68; 95% confidence interval, 1.3-44.1; P=.02) Pulsed-field gel electrophoresis patterns on Staphylococcus epidermidis isolates from four of the six cases were identical. These cases were performed on different days. Surgical resident Awas the only staff member present in the operating room for all cases caused by the epidemic strain. This S epidermidis strain, however, was not isolated from operating room staff. CONCLUSION: A surgical resident was significantly associated with infection. However, the cause of this outbreak was likely multifactorial. Changes occurring during the investigation included institution of vancomycin as routine prophylaxis and modification of surgical technique, which contributed to the resolution of the outbreak.     

Why we are wasting time in the operating theatre?

Objectives To determine reasons for delay during elective operating lists and suggest solutions. Design Prospective observational study. Setting A large under‐graduate teaching hospital. Participants Fifty‐five consecutive women undergoing elective gynaecological surgery under general anaesthesia. Interventions Every time point of individual patient's passage through the operating theatre (patients sent for, arrival in the anaesthetic room, general anaesthetic commenced, transfer to the operating theatre, surgery started, surgery completed, anaesthetic reversed, patient taken to recovery area) was documented. Main outcome measures Time intervals between the various time points with particular reference to wait by the anaesthetist and surgeon between cases. Results We monitored 55 operations carried out during 22 operating lists. Apart from the surgery itself (median 81 min per procedure), the longest interval was the time taken to get patients into the anaesthetic room from the ward (median 20 min). Although patients waited a median of 10 min before the start of anaesthesia, if the first procedure on the list was excluded, the anaesthetist was waiting for the patient to arrive in the anaesthetic room in 13/30 (43%) cases, wasting a median of 7 min per case. The surgeon had to wait a median of 22.5 min between operations. Conclusions Considerable operating theatre time is wasted while patients are transferred to and from the operating theatre resulting in both anaesthetists and surgeons having to wait between patients in a high proportion of cases, averaging 1 h during a 4 h operating list. Surgery could be made more time efficient by ensuring that patients arrive in the operating theatre complex early enough (to reduce time wasted for anaesthetists and surgeons), and by having two anaesthetists available at the end of surgery, one to reverse the anaesthetic while the other starts the next induction (to reduce time waste for the surgeon), coupled to adequate recovery area capacity. Copyright © 2008 John Wiley & Sons, Ltd.     

Pre-educational intervention survey of healthcare practitioners' compliance with infection prevention measures in cardiothoracic surgery: low compliance but internationally comparable surgical site infection rate

Surgical site infections (SSIs) are challenging problems leading to significant postoperative morbidity and mortality and may reflect the level of adherence to infection control policies. We used a structured observational method to collect data about infection control practices among surgeons, anaesthetists, nurses, cardiopulmonary bypass technicians and orderlies practising in the cardiac operating theatre during open heart surgery at Mater Dei Hospital. To prevent bias, we did not disclose the actual procedures observed to the surgical team members, but participants knew they were being observed for infection control practices. We measured the 30-day SSI rate by post-discharge telephonic surveillance among surviving open heart surgery patients who had consented to the survey. We observed practices during 30?randomly chosen operations and found higher levels of inadequate practices related to environmental disinfection, hand hygiene, operating room traffic and surgical attire of non-scrubbed personnel (anaesthesiologists and cardiopulmonary bypass technicians). In all, 140 of 155 patients who underwent open heart surgery were followed up, achieving a response rate of 91.5%. Superficial and deep SSI rates were 16.4% and 4.3% respectively, including both sternal and harvest site infections. We found poor compliance with infection control practices by non-scrubbed personnel involved in cardiac surgery and observed a high surgical site infection rate, the majority being leg wound infections following saphenous vein harvesting.     

The effect of surgical theatre head-gear on air bacterial counts.

The wearing of disposable head-gear in operating theatres is currently recommended for scrubbed and non-scrubbed staff. However, there is little evidence of its effectiveness as an infection control measure in casual or non-scrubbed theatre staff. The effect of head-gear on bacterial air counts was studied, using six volunteers, in a sealed room, with and without ventilation. Using a Casella slit sampler and a SAS Air Sampler, air counts ranged from 0.08 to greater than 2.9 colony forming units (cfu) m-3. The wearing of head-gear was not associated with a reduction in air counts but counts were lower with ventilation. We recommend that non-scrubbed staff no longer wear head-gear as effective ventilation probably counteracts any possible increased bacterial shedding. Scrubbed staff should continue to wear disposable head-gear because of their proximity to the operative field.     

Cardiac surgery productivity and throughput improvements

PURPOSE: The high variability in cardiac surgery length--is one of the main challenges for staff managing productivity. This study aims to evaluate the impact of six interventions on open-heart surgery operating theatre productivity. DESIGN/METHODOLOGY/APPROACH: A discrete operating theatre event simulation model with empirical operation time input data from 2603 patients is used to evaluate the effect that these process interventions have on the surgery output and overtime work. A linear regression model was used to get operation time forecasts for surgery scheduling while it also could be used to explain operation time. FINDINGS: A forecasting model based on the linear regression of variables available before the surgery explains 46 per cent operating time variance. The main factors influencing operation length were type of operation, redoing the operation and the head surgeon. Reduction of changeover time between surgeries by inducing anaesthesia outside an operating theatre and by reducing slack time at the end of day after a second surgery have the strongest effects on surgery output and productivity. A more accurate operation time forecast did not have any effect on output, although improved operation time forecast did decrease overtime work. RESEARCH LIMITATIONS/IMPLICATIONS: A reduction in the operation time itself is not studied in this article. However, the forecasting model can also be applied to discover which factors are most significant in explaining variation in the length of open-heart surgery. PRACTICAL IMPLICATIONS: The challenge in scheduling two open-heart surgeries in one day can be partly resolved by increasing the length of the day, decreasing the time between two surgeries or by improving patient scheduling procedures so that two short surgeries can be paired. ORIGINALITY/VALUE: A linear regression model is created in the paper to increase the accuracy of operation time forecasting and to identify factors that have the most influence on operation time. A simulation model is used to analyse the impact of improved surgical length forecasting and five selected process interventions on productivity in cardiac surgery.     

Environmental controls in operating theatres

Surgical-site infection is the leading complication of surgery. Normal skin flora of patients or healthcare workers causes more than half all infections following clean surgery, but the importance of airborne bacteria in this setting remains controversial. Modern operating theatres have conventional plenum ventilation with filtered air where particles >/=5 microm are removed. For orthopaedic and other implant surgery, laminar-flow systems are used with high-efficiency particulate air (HEPA) filters where particles >/=0.3 microm are removed. The use of ultra-clean air has been shown to reduce infection rates significantly in orthopaedic implant surgery. Few countries have set bacterial threshold limits for conventionally ventilated operating rooms, although most recommend 20 air changes per hour to obtain 50-150 colony forming units/m(3) of air. There are no standardized methods for bacterial air sampling or its frequency. With the use of HEPA filters in operating theatre ventilation, there is a tendency to apply cleanroom technology standards used in industry for hospitals. These are based on measuring the presence of particles of varying sizes and numbers, and are better suited than bacterial sampling. Environmental bacterial sampling in operating theatres should be limited to investigation of epidemics, validation of protocols, or changes made in materials which could influence the microbial content.     

普通胸外科术后感染分析

目的了解医院普通胸外科术后感染的相关因素,为预防和控制医院感染提供科学依据。方法对医院2006年1月1日-2011年8月31日普通胸外科术后患者进行流行病学调查,共获得病历718份。结果 718例患者中,手术后发生感染30例,感染率为4.18%,其中男性412例,感染17例,感染率为4.13%,女性306例,感染13例,感染率为4.25%,男、女感染率差异无统计学意义;在医院普通胸外科术后感染呼吸系统疾病占36.67%,泌尿系统疾病占30.00%,消化系统疾病占23.33%,其他系统疾病等占10.00%;普通胸外科术后感染影响因素是感染并发部位、手术持续时间、住院时间、抗菌药物使用种类等。结论患者的手术持续时间、手术部位、住院时间以及手术后抗菌药物使用种类等是造成普通胸外科术后感染的主要因素;手术室医护人员应严格按时间、程序洗手,并加强手术室空气消毒管理。