Influence of operating room surface contamination on surgical wounds: a prospective study

The influence of operating room contamination on wound infection rates in clean, clean-contaminated, contaminated, and septid procedures was studied by a prospective randomized study of 2,020 surgical wounds. Operating room surface contamination was assessed by the RODAC bacterial plate method. Control rooms uniformly received Wet-Vac cleaning between operations. Experimental rooms were not cleaned between consecutive clean operations, but were cleaned after contaminated operations. The difference in surface contamination between groups of experimental and control rooms was found to be significant at the P less than .05 level. Patients operated on in experimental and control rooms were followed up postoperatively to assess whether they experienced wound infection. No statistically significant differences in wound infection rates were found between experimental and control room operations as total groups, clean procedures, or operations of long duration.     

Formal teaching of basic surgical skills

Attainment of the practical skills in surgery is an integral part of surgical training. Basic skills must be mastered prior to attempting more complex tasks and bad habits learned early are difficult to correct. A survey of advanced surgical trainees at this hospital demonstrated that skills were usually acquired during sessions in the operating theatre, often in an ad hoc manner. We report our experience in establishing a workshop-based skills course. The program included handling of instruments, knot tying, types and applications of needles and suture materials, wound care, ligation of vessels, and assisting at operation. Following completion of the course and demonstration of their competence, participants were awarded a certificate in basic skills. Participants reported increased confidence and involvement in operative surgery after the course and an increased interest in a career in surgery. We believe the intern year is the most appropriate time to teach such skills, but tuition need not to be restricted to this group. Teaching basic surgical skills in the workshop setting is feasible and advantageous.     

Bacterial airborne dispersal during the drilling of infected bone (author's transl)

The hazards of infection by bacterial airborne dispersal secondary to drilling bone in the surgical treatment of infection of the air spaces of the skull were assessed experimentally. This included estimation of the furthest distance that the cooling fluid, using coloured water, and the bone chips of a dry petrous temporal bone can be thrown, and the spread of the fine dust produced by the drilling using a staph. albus suspension as the rinsing fluid. The drops and bone chips were flung to a distance of about 90 cm in the working area around a cutting burr rotating at 80 000 r.p.m. The fine dust thrown off by cutting and diamond burrs and the infected fluid mist stays suspended in the air for hours and can be carried across the whole room by air currents. The surgeon and operating theatre personnel are therefore always at risk of infection. Preventive measures are discussed.     

Air quality and microbiologic contamination in operating theatres

The present study concerns the air quality and microbiological contamination in two newly built operating theatres; one with laminar air flow (LAF) equipment for cardio-thoracic operations, and one with conventional ventilation for urological operations. Both theatres had an identical number of air exchanges (17/h), identical microclimatic conditions and they employed the same cleaning procedures. In the LAF-ventilated operating theatre bacterial contamination of the air was effectively reduced to less than 10 colony-forming units (CFU)/m3 in all 125 samples (1 m3 per sample) tested. In most samples, 118/125, the bacterial count was less than 5 CFU/m3, despite the presence of ten persons. The conventionally ventilated theatre reached values up to 120 CFU/m3 during the most active period of the day when approximately seven persons were present. The LAF ventilation reduced both the content of particles in the air and contamination by bacteria on the floor. In both theatres cleaning procedures had only a low impact on CFU in the air and on the floor. The use of diathermia markedly increased the level of small particles in the air, and this may influence the air quality in the operating theatres.     

Influence of local air suction on the density of air-borne bacteria during cementation of alloplasties

At joint replacement operations local air suction is used to reduce the air pollution from organic solvents in the operation theatre during insertion of cement and prosthesis. In order to find out whether the local suction in an ultraclean-air operation theatre with laminar airflow influenced the number of colony forming units (cfu) of bacterial in vicinity of the wound, one m3 of air was sampled 20 cm and one metre from the wound before, during and after use of local suction during insertion of cement and prosthesis using a Sartorius membrane filter sampler. There was no significant difference between the groups in the numbers of cfu of bacteria found. It is concluded that use of local air suction over the operative area while cementing hip prosthesis does not affect the number of bacteria in the vicinity of the operation.     

Kirschner wire placement in the emergency room. Is there a risk?

To evaluate the safety of inserting Kirschner wires into bones or across joints in a setting other than a completely sterile operating theatre, a prospective study of all hand fractures treated by closed reduction and internal fixation was conducted in a mid-city Emergency Department. Indications for percutaneous fixation were displaced, unstable long bone fractures of the hand. 71 fractures in 68 patients were treated, and in 91% the fixation crossed a joint. No patient developed osteomyelitis or pyarthrosis, and there was no deep pin track sepsis. Seven patients with open fractures healed without infection or delayed union. Patients in whom data were available obtained 90% to 95% of the motion of the contralateral digit. The taboo against percutaneous fixation of fractures in a non-operating theatre setting is not warranted. The procedure can be performed with minimal complications in an out-patient setting.     

Designing an anaesthesia data management system for a medium size country hospital. A report of four years experiences

By the end of 1990 the anaesthesia department of the Offenburg hospital, a 500 bed hospital, started to install a data management system in the main operating theatres. In a first phase, 23 PCs were installed in 7 induction rooms and 7 theatres as well as in the 9-bed recovery-room. All PCs are connected via ethernet to a VAX-server. The main functions of the system may be summarized as follows: 1) On-line data acquisition from the patient monitor and from the anaesthesia machine (the ventilator); 2) Off-line data entry of other variables including drugs, fluids and postop. orders as well as demographic and administrative data; 3) Data transfer from induction room to theatre and from theatre to the recovery room; 4) Printout of an automatic anaesthesia record at the end of each case--a hand-written protocol no longer required; 5) Storage of data-files on the VAX-server with possibility of reviewing individual cases and also of performing all types of statistical analysis. The set-up of the whole system including 12 ICU beds and other workstations (total of 42 PC-stations) is described as well as hard- and software used. Problems encountered during installation of hardware and experiences during implementation of software are briefly discussed. A short overview is given concerning future development.     

Do costs decide? Disposable or reusable instruments in laparoscopic cholecystectomy?

Laparoscopic cholecystectomy requires new and specially designed instruments. Both, disposable and reusable instruments are available and frequently used. The purpose of this analysis was to compare these instruments with regard to safety and costs. A complete and detailed calculation comprising all cost components was performed using data from 534 patients. Safety of the procedure was assessed by the documentation of all events during and after laparoscopic cholecystectomy in 1000 consecutive patients. Costs: A standard operation with reusable instruments costs DM 3395. One third of these costs are non-hospital costs. Every postoperative day in hospital adds DM 234.44, every minute of operation time adds DM 4.88. Using a complete of disposable instruments causes an increase in total costs of DM 1117, which mainly results from the costs of the instruments themselves. Safety: Among 1000 operations all performed with reusable instruments, 82.3% were uneventful for the patient. The wound infection rate was 2.3%. Until today no injuries of the staff caused by these instruments were observed. These findings demonstrate that reusable instruments are safe and cost-effective.     

The sunscreening effect of urocanic acid

Urocanic acid (UCA), present in the stratum corneum, is a major absorber of ultraviolet (UV) radiation and, on UV exposure, is induced to isomerize from the naturally occurring trans-isomer to the cis-isomer. Cis-UCA has been shown to have immunosuppressive properties, while trans-UCA may act as a natural sunscreen due to its UV-absorbing properties. The photoprotective capacity of UCA was investigated in this study. Minimal erythema dose (MED) was determined on normal buttock skin in 36 healthy subjects and the concentration of UCA isomers was measured on the skin adjacent to the test site. On the contralateral buttock. MED was determined 20 min after application of trans-UCA 5% in a cream base. The UCA cream gave a sun protection factor of 1.58. The amount of UCA applied was, however, 20-200 times higher than the amount of UCA found in normal skin, making a sunscreening effect of naturally occurring UCA very low. This was further supported, by a lack of correlation between naturally occurring UCA and the UV sensitivity of each subject determined by the MED.     

Determination of the viremia threshold for dental cross-infection in a mouse model

An animal model of dental virus transmission was developed using the lactate dehydrogenase-elevating virus (LDV) of mice to study cross infection. Mouse-to-mouse cross-infection was carried out by scaling the teeth of LDV-infected donor mice with dental instruments, immediately prior to using the contaminated instruments on the teeth of recipient indicator mice. The level of donor viremia was found to correlate with the rate of virus cross-infection, with a viremia threshold level of 10(7.5) ID50/ml observed for dental cross-infection. The blood volume transferred during dental cross-infection was approximately 10(-4) to 10(-5) ml, demonstrating the inefficiency of virus cross-infection, since deposition of about 1000 virions on dental instruments was associated with the threshold limit. Virus transferred during dental cross-infection rapidly entered the blood circulation, showing that dental cross-infection was not dependent on an oral infection. The results from these model studies predict the general inefficiency of dental instrument virus cross-infection, and a further reduced likelihood of dental cross-infection with appropriately cleaned instruments.     

Wedding rings and hospital-acquired infection

Some theatre nurses are reluctant to remove their wedding rings when scrubbing up. This article reviews the literature and concludes that keeping rings on may put the patient at risk of nosocomial (hospital-acquired) infection.     

Reduction of hospital resources utilization in vascular surgery: a four-year experience

PURPOSE: Managed care whether through risk or through capitated contracts results in reduction in resources, reduced length of hospital stay, and reduced utilization of hospital resources (collectively referred to as resource reductions). These resource reductions will become even more noticeable as a greater proportion of Medicare patients who need vascular operations select a managed-care senior product. We examined the results of a 4-year experience with resource management in an academic vascular surgery practice during which best practice plans were developed and implemented. METHODS: We analyzed hospital cost data, which included both total hospital and intensive care unit length of stay, average units per operation for laboratory, pharmacy, and radiology services and operating room and direct hospital costs for 257 carotid endarterectomies performed over fiscal years (FY) 1994, 1995, 1996, and 1997 (6 month data) and 175 infrainguinal bypass procedures performed during the same period. RESULTS: For carotid endarterectomy, length of stay decreased 66% over the 4-year period to an average of 2.07 days in FY97. Both radiology and pharmacy utilization were reduced after the first year of institution of best practice plans (56% and 32% respectively) with 4-year total reductions of 86% and 55% by FY97. The most notable changes included elimination of routine postoperative laboratory testing, use of aspirin rather than low-molecular-weight dextran, emphasis on oral rather than intravenous vasoactive drugs, and routine use of duplex scanning alone rather than angiography for diagnosis after FY94-95. The length of operating room time for carotid endarterectomy remained relatively constant from FY94 to FY97. As a result of these multiple factors, our study showed a 30% decrease in total average direct hospital costs for carotid endarterectomy from $9974 to $7002 in this 4-year period. Infrainguinal bypass graft procedures showed a progressive decrease in total cost of 28% for patients without complications to $15,186 but remained unchanged for those with complications. Laboratory use, pharmacy use, and radiology use were not significantly different. CONCLUSIONS: Case management for patients undergoing carotid endarterectomy and infrainguinal bypass grafting involving an integrated team of vascular surgeons, surgical house staff, a dedicated vascular nurse, and a social work case manager resulted in dramatic reductions both in length of stay and hospital resource utilization. As these costs decreased, operating room expenses assumed increasing importance. Operating room costs account for 60% of the direct costs of carotid endarterectomy and a comparable percentage for uncomplicated infrainguinal bypass grafting. Further substantial reductions in direct hospital costs will depend primarily on reductions in operating room costs, particularly those related to length of time in the operating room.     

Serious infections due to Pseudomonas aeruginosa

Infections due to Ps. aeruginosa are a problem in the tropics as in other parts of the world. Over a four year period, 15 patients attending University College Hospital, Ibadan, were proved to have septicaemia due to this organism and 13 patients died rapidly as a direct result of the infection. The two patients who survived the acute episode had received immediate treatment with at least one antibiotic active against Ps. aeruginosa: a third patient, who received immediate appropriate antibiotic therapy, was already suffering from aplastic anaemia and died rapidly despite treatment. The remaining patients received inappropriate antibiotic therapy because pseudomonas infection was not suspected at the time the diagnosis of septicaemia was made. Patients most at risk appear to be the very young and those with pre-existing malignant or other conditions affecting the defence mechanisms of the body: it is suggested that routine initial management of such patients should include a blood culture, followed by immediate treatment with an antibiotic combination that includes at least one agent likely to be active against Ps. aeruginosa. The development of medical services can lead to the introduction of ophthalmic or other operations on tissues that are highly susceptible to infection before facilities are provided for the maintenance of a pathogen-free environment. Following an outbreak of eye infection after cataract extractions, carried out in an old and unsatisfactory theatre, wide-spread room contamination was demonstrated with the same strains of Ps. aeruginosa that had been responsible for the clinical infections. Chemical disinfection of the theatre floor failed to eliminate the organisms, although other experiments suggested that the drying effect of air-conditioning would be successful in this respect. The wisdom of introducing such operations before the provision of adequate facilities is seriously questioned.     

The measurement of quality of care in public sector psychiatric services based on consumer expectations

In this study the expectations of consumers of public sector psychiatric care in South Africa were identified, and formulated in the form of 13 standards, each with a set of criteria. During this phase input from the literature was incorporated, and expectations were validated with different groups of consumers, so that rural/urban, ethnicity and regional differences were taken into account. Based on the comprehensive set of standards and criteria, four instruments were developed to measure attainment of these standards. These included a questionnaire to consumers and one to the Director of Mental Health. It also included two schedules to be filled in by observers during site visits to hospital units and clinics. The observer teams included community members and consumers. The content validity of the instruments was established by setting out the items measuring each criterium, and validating that with a group of experts. The instruments were then tested in one province. The inter-rater reliability of the site visit schedules was calculated as 0.94, and the coding of the Director questionnaire by different coders was also tested. The average performance on all criteria was calculated, using items from all four data collection instruments. In the process items were revised, coding instructions developed, and criteria adjusted.     

A metastatic neuroendocrine tumor with exceptional outcome!

BACKGROUND: Propionibacterium acnes has been described as a causative agent of postoperative endophthalmitis. This gram-positive, immotile, non-spore-forming bacterium is highly pleomorphic and grows under conditions of low to no oxygen concentration. It is commonly found on the skin at the openings of sebaceous glands and on hairs. A near-symptomless postoperative endophthalmitis occurs particularly when Propionibacteria are enclosed in the capsular bag. We investigated to what extent the number of P. acnes in the conjunctival sac can be reduced by preoperative disinfection with polyvidone iodine (1%). PATIENTS AND METHODS: A total of 261 patients with intrabulbar surgery had two conjuctival swabs taken: the first immediately prior to preoperative preparation in the operating theatre, following in-patient application of antibiotic eye drops (Polymyxin-B-sulfat, Neomycinsulfat and Gramicidin in combination); the second swab was taken after disinfection with polyvidone iodine before opening the conjunctiva. RESULTS: Of the 261 swabs, 60 (23%) taken prior to polyvidone iodine application were positive for Propinibacterium acnes. Following polyvidone iodine treatment, a further 5 (1.9%) remained culture-positive. After disinfection, 55 (92%) of the 60 positive swabs for Propionibacterium acnes remained culture-negative. CONCLUSIONS: We concluded that a significant reduction of P. acnes can be achieved by preoperative application of polyvidone iodine (1%) (P < 0.001).     

Apoptosis of human intestinal epithelial cells after bacterial invasion

Epithelial cells that line the human intestinal mucosa are the initial site of host invasion by bacterial pathogens. The studies herein define apoptosis as a new category of intestinal epithelial cell response to bacterial infection. Human colon epithelial cells are shown to undergo apoptosis following infection with invasive enteric pathogens, such as Salmonella or enteroinvasive Escherichia coli. In contrast to the rapid onset of apoptosis seen after bacterial infection of mouse monocyte-macrophage cell lines, the commitment of human intestinal epithelial cell lines to undergo apoptosis is delayed for at least 6 h after bacterial infection, requires bacterial entry and replication, and the ensuing phenotypic expression of apoptosis is delayed for 12-18 h after bacterial entry. TNF-alpha and nitric oxide, which are produced as components of the intestinal epithelial cell proinflammatory program in the early period after bacterial invasion, play an important role in the later induction and regulation of the epithelial cell apoptotic program. Apoptosis in response to bacterial infection may function to delete infected and damaged epithelial cells and restore epithelial cell growth regulation and epithelial integrity that are altered during the course of enteric infection. The delay in onset of epithelial cell apoptosis after bacterial infection may be important both to the host and the invading pathogen since it provides sufficient time for epithelial cells to generate signals important for the activation of mucosal inflammation and concurrently allows invading bacteria time to adapt to the intracellular environment before invading deeper mucosal layers.     

Involvement of substance P in pial arteriolar vasodilatation during pneumococcal meningitis in the rat

The present study investigated whether the endogenous vasodilating neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) contribute to pial arteriolar vasodilatation in the early phase of pneumococcal meningitis in the rat. Using a closed cranial window preparation we measured the diameters of pial arterioles during 4 h after pneumococcal infection. Arteriolar vasodilatation in infected rats was significantly attenuated by pretreatment with the SP-antagonist spantide up to 3 h after infection. Neither post-treatment with spantide (administered 2 h after infection) nor pretreatment with the CGRP antagonist CGRP(8-37) affected the pneumococci-induced pial arteriolar dilatation. These data suggest that SP is involved as a mediator in early pneumococci-induced dilatation of pial arterioles.     

Primary and secondary stroke prevention in atrial fibrillation

The correlation between pharmacokinetic parameters and the in-vivo effect of antibiotics in relation to bacterial growth phases was evaluated using the mouse peritonitis model with a penicillin-resistant pneumococcus. Different 8 h dosing regimens were applied, with different total doses and initiated at different times during the bacterial growth phase. The effect was measured as the decline in bacterial counts in the peritoneal cavity. The pharmacokinetic parameters showed major changes during the phases of growth, as the serum elimination of penicillin decreased during the infection. The same effect of dosing regimens was observed in the exponential and stationary phases. In two regimens where T(>MIC) (the time the serum concentration exceeded the MIC) was 50% of the treatment period, a significantly better effect was achieved with a 2 hourly regimen than with a regimen with treatments every 20 min. The T(>MIC) of each dose was shown to be a critical parameter for achieving an effect in all growth phases. The maximum effect of penicillin, a 5-6 x log10 decline in bacterial counts in the peritoneum of the mice, was achieved when T(>MIC) was >50% of the treatment time or longer than approximately 40 min of each dose. The 50% effective dose for protection after a single injection, ED50, was measured in the different phases of the infection and found to increase with the duration of the pneumococcal infection, while mice treated 24 h after challenge were beyond therapeutic range. The correlation between the effect of penicillin and pharmacokinetic parameters appears to follow the same rules during the different in-vivo growth phases of pneumococci.     

Selective suppression of stress-activated protein kinase pathway by protein phosphatase 2C in mammalian cells

Between 1985 and 1987, 1837 primary total knee arthroplasty (TKA) prostheses were implanted in 1503 patients. Group I included 843 knee with metal-backed patellar components (MBPC), and group II included 994 knees with all polyethylene patellar components (APPC). Follow-up averaged 5.7 years (range, 2 to 11 years). Twenty-four MBPC (2.9%) and 16 APPC TKA cases (1.6%) developed deep infection. In the time interval between arthroplasty and 2-year follow-up, eight MBPC and 11 APPC knees developed deep periprosthetic infection. The difference in the cumulative probability of infection between the two groups during this time interval was not significant (relative risk, 0.9; 95% confidence interval [CI], 0.3-2.1; P = 0.73). However, after the 2-year follow-up, 16 MBPC and 5 APPC knees developed late infection, and the difference in the cumulative probability of infection between the MBPC and APPC knees during this time interval was significant (relative risk, 3.1; 95% CI, 1.1-8.5; P = 0.02). Although the mechanism for this increased risk of these late infections is not well understood, the attendant synovitis, effusion, and relative hyperemia of these knees in the presence of the particulate metal and polyethylene debris may increase the potential of bacterial seeding to these prostheses. Particulate metal debris has been previously shown to suppress bacterial phagocytosis and may play a role in the pathogenesis of these infections. We propose that the presence of metal-backed patellar failure represents a "prosthesis at risk" for the development of late prosthetic infection.