Contamination during removal of cement in revision hip arthroplasty. A cadaver study using ultrasound and high-speed cutters

Instruments used in surgery which rotate or vibrate at a high frequency can produce potentially contaminated aerosols. Such tools are in use in cemented hip revision arthroplasties. We aimed to measure the extent of the environmental and body contamination caused by an ultrasound device and a high-speed cutter. On a human cadaver we carried out a complete surgical procedure including draping and simulated blood flow contaminated with Staphylococcus aureus (ATCC 12600). After cemented total hip arthroplasty, we undertook repeated extractions of cement using either an ultrasound device or a high-speed cutter. Surveillance cultures detected any environmental and body contamination of the surgical team. Environmental contamination was present in an area of 6 x 8 m for both devices. The concentration of contamination was lower for the ultrasound device. Both the ultrasound and the high-speed cutter contaminated all members of the surgical team. The devices tested produced aerosols which covered the whole operating theatre and all personnel present during the procedure. In contaminated and infected patients, infectious agents may be present in these aerosols. We therefore recommend the introduction of effective measures to control infection and thorough disinfection of the operating theatre after such procedures.     

Contamination of banked femoral head allograft: incidence, bacteriology and donor follow up

BACKGROUND: Allograft donations are not uncommonly found to be contaminated. The issue of contaminated donations from live donors at the time of surgery, and the significance of this to the patient in terms of subsequent sepsis of the arthroplasty, were examined. METHODS: The donations of femoral heads to the Queensland Bone Bank over a 9-year period were reviewed, and the incidence and bacteriology of contamination were detailed. Clinical outcomes were determined for donors who had positive cultures at the time of retrieval and they were compared with those of culture-negative donors. RESULTS: Between March 1987 and February 1996, 232 femoral heads were donated to the Queensland Bone Bank. Four specimens were sent for culture with each femoral head (surface swab of femoral head, acetabular swab, bone biopsy and capsule). In 51 cases, one or more positive cultures were obtained (22% contamination rate). The majority of organisms cultured were Staphylococcus epidermidis. One hundred and seventy donations came from surgery performed at the Princess Alexandra Hospital, and 40 femoral heads were considered contaminated. Deep infection was recorded in one of the 40 cases with contaminated donations and three out of 130 non-contaminated donations had subsequent septic episodes. CONCLUSION: The contamination rate detailed in the present report is higher than in most series. This may be due to the fact that four bacteriological specimens are taken to assess contamination. Two of these specimens are tissue samples which yielded more positive results than did the two swabs. All other series take no more than two bacteriological specimens, which are usually bone swabs. These are shown to have a poor yield of positive cultures. Therefore there is a significant underestimation of contamination rates by other bone banks. This has implications for the recipients of bone from those banks, particularly when the allograft material is not secondarily sterilized. This is important given increasing allograft usage, and the increasing numbers of revision joint arthroplasty and impaction grafting procedures being performed. Sterilization of all bone by irradiation to 25 kGy is recommended.     

Comparison of glove donning techniques for the likelihood of gown contamination. An infection control study

The creation of an optimal environment, whenever major joints are opened or metal is implanted into bone, is important to reduce infection following orthopaedic surgery. Following normal hand washing protocols, it is possible that pathogenic bacteria can remain on the skin. These bacteria may inadvertently be transferred to the surgical gown during the glove donning procedure and therefore contamination of the surgical wound could follow. We aimed to determine whether there is a difference between three differing glove donning techniques, open, closed and scrub staff assisted, in terms of accidental gown contamination, as the optimum method is unknown. Three differing glove donning techniques were assessed using ultra-violet (UV) lotion, applied to the hands after the scrub, to demonstrate patches of contamination on the surgical gowns. Two studies were carried out. An initial pilot study with theatre personnel and the main study by a single surgeon rehearsed in the various techniques. The region and size of contamination patches were documented. In the pilot study 12 out of 13 individuals were seen to have patches of UV fluorescent gown contamination following an observed scrub. In the main study, both the open and closed technique had a 100% gown contamination rate. This was concentrated around the cuff region. There were no contamination patches in the scrub staff assisted technique. Glove donning, using the scrub staff assisted technique can minimise the possibility of gown contamination. This is important in surgical procedures where the results of infection can be devastating.     

Bacterial contamination in postmortem bone donors

We analyzed factors influencing the contamination rate of allografts and blood samples obtained from postmortem bone donors. 5,710 allografts were harvested, from 550 donors of which 3,164 (55%) were swab culture negative. Blood cultures were positive in 140 donors (26%). The risk of graft contamination increased with each extra team member (Odds Ratio 1.9). It was also higher with organisms of greater virulence in donors with a positive blood culture (OR 3.5). The risk of blood contamination increased per hour postmortem (OR 1.1) and the same increase was seen with organisms of high virulence. In donors with multiple trauma, the risk of blood contamination with organisms of high virulence was greater (OR 8.2), but smaller in donors with preceding organ procurement (OR 0.1). To minimize the bacterial load, donors should be obtained in operating rooms, using aseptic techniques with only a few personnel for procurement. The postmortem time should be kept to a minimum. The procurement cultures from donors with multiple trauma should be carefully interpreted. Blood cultures should be taken into account, since these can help to find contamination not detected by swab cultures.     

Bacterial contamination in postmortem bone donors

We analyzed factors influencing the contamination rate of allografts and blood samples obtained from postmortem bone donors. 5,710 allografts were harvested, from 550 donors of which 3,164 (55%) were swab culture negative. Blood cultures were positive in 140 donors (26%). The risk of graft contamination increased with each extra team member (Odds Ratio 1.9). It was also higher with organisms of greater virulence in donors with a positive blood culture (OR 3.5).

The risk of blood contamination increased per hour postmortem (OR 1.1) and the same increase was seen with organisms of high virulence. In donors with multiple trauma, the risk of blood contamination with organisms of high virulence was greater (OR 8.2), but smaller in donors with preceding organ procurement (OR 0.1). To minimize the bacterial load, donors should be obtained in operating rooms, using aseptic techniques with only a few personnel for procurement. The postmortem time should be kept to a minimum. The procurement cultures from donors with multiple trauma should be carefully interpreted. Blood cultures should be taken into account, since these can help to find contamination not detected by swab cultures.     

左半结肠癌急性梗阻一期切除吻合的安全保证──彻底快速而无污染的肠减压术

目的：研究一种彻底快速而毫不污染手术野的术中肠减压方法，以便提高手术的安全性。方法：游离系膜后，钳夹下将拟切除肠段的下端先切断，将其近侧断端置入并固定于粘附在手术床边的塑料袋中；松开肠钳，肠内容物自由流入袋内；双手交替推挤膨胀的肠段，由近而远，由小肠向大肠，直至大、小肠的内容物彻底排空。钳夹下切断上端，移除切下的肠段和充满粪便的塑料袋。结果：使用本法行肠减压术，一期切除急性梗阻的左结肠癌３１例，均未发生吻合口漏，创口一期愈合。另有６例肝段切除同时切除未作肠道准备的结肠癌，亦取得同样结果。同法亦用于各种急性小肠梗阻，均未造成腹腔污染。结论：本法可推荐为术中肠减压的首选方法。     

A quick and effective method of limb preparation with health, safety and efficiency benefits

INTRODUCTION

Pre-operative limb preparation (PLP) usually involves lifting the limb and holding it in a fixed ‘static’ posture for several minutes. This is hazardous to theatre staff. Furthermore, ‘painting’ the limb can be time consuming and difficult areas such as between toes and fingers may remain unsterile. We demonstrate the time efficiency and asepsis achieved using the ‘sterile bag’ preparation technique. An additional advantage is the ability to prepare and anaesthetise a limb prior to theatre, increasing efficiency substantially for units with a large throughput of cases, such as day-case hand surgery lists.

METHODS

We monitored the duration of PLP in 20 patients using the ‘sterile bag’ technique compared to 20 patients using a conventional ‘painting’ method. Additionally, microbiology samples acquired from prepared upper limbs of 27 sequential patients operated on by a single surgeon over a two-month period were sent for culture immediately prior to commencement of surgery.

RESULTS

The mean duration of the ‘sterile bag’ PLP was significantly lower than that of the conventional method (24 seconds vs 85 seconds, p=0.045). The technique can take as little as ten seconds (n=1). Final microbiology reports showed no growth for any of the 27 patients from whom a culture sample was taken.

CONCLUSIONS

The sterile bag technique is effective in achieving asepsis, has the potential to increase theatre efficiency and reduces manual handling hazards compared to the conventional method. It is now taught to all theatre staff in our hospital during manual handling training. It can be undertaken in approximately ten seconds with practice for the upper limb.     

Indwelling urinary catheter infections in small community hospital. Role of urinary drainage bag

Ninety cases of closed drainage urinary catheterization were studied by daily bacteriologic monitoring with Microstix. In 23 per cent of the patients bacteriuria developed, and 92.6 per cent of all catheter infections occurred within three days. These infections occurred primarily in postsurgical patients, and were probably related to initial contamination during catheter insertion. Only 1 patient had a positive drainage bag urine culture prior to the development of bladder bacteriuria. At our institution poor catheter technique was much more important as a risk factor of nosocomial urinary tract infection than an antiseptic drainage bag system.     

Environmental and body contamination through aerosols produced by high-speed cutters in lumbar spine surgery.

STUDY DESIGN: A cadaver study to evaluate contamination in the operating room through the use of a high-speed bone cutter. OBJECTIVES: To determine the grade of contamination of animate and inanimate objects through an aerosol intraoperatively, produced by a high-speed cutter during lumbar laminectomy. SUMMARY OF BACKGROUND: In spinal surgery, high-speed cutters are used that produce an aerosol consisting of a mixture of irrigation solution, blood, and tissue debris. Such aerosols can be contaminated with potential pathogens. The surgical personnel and the environment are therefore exposed to a contamination risk. METHODS: Laminectomies at three points (L2-L4) were performed on a human cadaver using a high-speed cutting device. The aerosol produced by the irrigation solution was contaminated with Staphylococcus aureus ATCC 12600. To detect the contamination of the environment and of the surgical team, surveillance cultures were used. RESULTS: By air sampling, staphylococci were detected in the operating room at an extension of 5 by 7 m. The surgical team showed extensive face and body contamination with S. aureus. Despite protection by a barrier drape, similar contamination was observed on both the cadaver's head and the anesthesiologist. CONCLUSIONS: The use of high-speed cutters in spinal surgery produces an aerosol that can be contaminated with blood-borne pathogens from infected patients. This aerosol is spread over the whole surgical room and contaminates the room and all personnel present. It is therefore critical to ensure that effective infection control measures are performed, not only by the surgeons but by everyone present in the operating room. The room itself must be sufficiently disinfected after such procedures.     

Outcome following deep wound contamination in cemented arthroplasty

Infection remains a devastating complication of joint replacement surgery causing a significant burden to both patient and surgeon. However, despite exhaustive prophylactic measures, intraoperative contamination still occurs during cemented arthroplasty with current infection rates of 1-2%. A study was undertaken to determine the incidence of perioperative contamination in cemented arthroplasty patients, to identify contaminating organisms, to identify contaminated regions within the operative wound, to identify factors associated with increased contamination, and finally to assess the medium-term clinical outcome in patients with confirmed intraoperative wound contamination. Eighty consecutive patients undergoing hip and knee cemented arthroplasty were prospectively enrolled over a 6-month period. All scrubbed personnel wore total body exhaust isolation suits and procedures were carried out in ultra-clean air theatres. Of 441 samples, contamination was identified at 21 sites (4.8%) representing a cohort of 18 patients (22.5%). Longer duration of surgery predisposed to higher contamination rates while lower contamination rates were significantly related to fewer gowned personnel within the ultra-clean system, and fewer total personnel in theatre during the procedure. None of the patients developed clinical evidence of deep prosthetic infection at follow-up. We noted a high incidence of intraoperative contamination despite standard prophylaxis. However, this was not reflected by a similar rate of postoperative infection. This may be due to a small bacterial inoculum in each case or may be due to the therapeutic effect of perioperative intravenous antibiotic prophylaxis.     

Fundamental study on the collection of prostatic fluid using catheter]

The catheter for expressed prostatic secretions (EPS) collection was newly developed for the purpose of protecting EPS from the contamination of the urethral bacteria. This catheter is blind-ended, and has several lateral windows and a balloon between the end and the windows. The procedure of EPS collection using this catheter is as follows; first the catheter is inserted into the urethra, then a balloon is blown up. The catheter is extracted during massage of the prostate and finally EPS is aspirated through the internal lumen of the catheter. In 23 male patients who had neither urinary tract infection nor genital infection, this catheter method was carried out. Before inserting the catheter, the urethral swab was obtained, then culture of the swab and the EPS was done. The catheter method protected against contamination with bacteria in 56%, with Ureaplasma urealyticum in 40%, and all contaminations in 44% of all cases.     

Can sterility of stripped iodophor-impregnated plastic adhesive drape be maintained at the time of incision closure in total hip arthroplasty?

ObjectiveThe aim of this study was to analyze the contamination rates of the skin under the iodophor-impregnated plastic adhesive drape (IOD) at the time of incision closure in total hip arthroplasty (THA).MethodsA total of 225 patients undergoing primary THA (28 men, 197 women; mean age=65 years; age range=30–85) were included in this study. After asepsis using a solution of 1% chlorhexidine with 83% alcohol by volume, the surgical site was painted with a 10% povidone-iodine solution, and IOD was attached tautly at the start of surgery. Swabs of the surgical site were collected as follows: swab A from the skin before IOD application, swab B from the surface of the IOD at the time of incision closure, and swab C from the skin after peeling back the IOD. The obtained samples were promptly sent for microbiological analysis. The contamination rate was determined for swabs A, B, and C, and the contamination rate of swab C was compared with that of swabs A and B, and the bacterial species were identified.ResultsPositive cultures were seen in 8 cases (3.6%) for swab A, 10 cases (4.4%) for swab B, and 22 cases (9.8%) for swab C. The contamination rate of swab C was significantly higher than that of swabs A (p=0.008) and B (p=0.028). Coagulase-negative Staphylococcus (n=10) and Cutibacterium acnes (n=7) were the most frequently cultured microorganisms from swab C.ConclusionIn THA, the contamination rate of the skin after peeling off the IOD before incision closure was higher than that of the skin immediately after sterilization with povidone-iodine and higher than that on the IOD at the time of incision closure. The detected bacterial species were considered clinically significant pathogens. Preventive measures against infection, such as minimizing stripping of the IOD or re-sterilizing bare skin after IOD stripping, should be instituted in consideration of these findings when performing THA using IOD.     

Theatre Shoes — A Link in the Common Pathway of Postoperative Wound Infection?

INTRODUCTION

Operating department staff are usually required to wear dedicated theatre shoes whilst in the theatre area but there is little evidence to support the beneficial use of theatre shoes.

PATIENTS AND METHODS

We performed a study to assess the level of bacterial contamination of theatre shoes at the beginning and end of a working day, and compared the results with outdoor footwear.

RESULTS

We found the presence of pathogenic bacterial species responsible for postoperative wound infection on all shoe groups, with outdoor shoes being the most heavily contaminated. Samples taken from theatre shoes at the end of duty were less contaminated than those taken at the beginning of the day with the greatest reduction being in the number of coagulase-negative staphylococcal species grown. Studies have demonstrated that floor bacteria may contribute up to 15% of airborne bacterial colony forming units in operating rooms. The pathogenic bacteria we isolated have also been demonstrated as contaminants in water droplets spilt onto sterile gloves after surgical scrubbing.

CONCLUSIONS

Theatre shoes and floors present a potential source for postoperative infection. A combination of dedicated theatre shoe use and a good floor washing protocol controls the level of shoe contamination by coagulase-negative staphylococci in particular. This finding is significant given the importance of staphylococcal species in postoperative wound infection.     

The bacteriology of bone allografts.

We report the contamination rate in the Cambridge bone bank of 35 consecutive allograft specimens, all harvested in a clean-air environment, using a strict aseptic technique and antibiotic cover. Five of 27 femoral heads taken from living donors and three of eight massive allografts taken from cadavers were found to be contaminated. The contaminated femoral heads were discarded. All massive allografts were rendered sterile by gamma-irradiation. It is important to exclude bacteriological contamination of harvested and banked bone.     

Laryngeal mask and anaesthetic waste gas exposure

In recent years there has been a growing awareness of the possible hazards caused by anaesthetic gases in operating theatres. The laryngeal mask airway provides an alternative both to tracheal intubation and the face mask although the implications for operating theatre contamination have not been quantified. This paper describes the incidence and magnitude of exposure of theatre personnel to waste anaesthetic gases during laryngeal mask airway anaesthesia. The leakage of anaesthetic gases to the anaesthetist's breathing zone was monitored using a Bruel & Kjaer Multi Gas Monitor, Type 1302 during 50 general anaesthetics employing either spontaneous (n = 24) or controlled (n = 26) ventilation. All patients were anaesthetised with propofol, alfentanil and nitrous oxide. There was no statistically significant association between the amount of anaesthetic gas leakage and ventilation method. The laryngeal mask airway meets occupational safety requirements on nitrous oxide concentrations in the operating theatre environment.     

结肠癌急性梗阻一期切除吻合的肠减压方法

目的 介绍一种彻底快速而毫不污染手术野的术中肠减压方法,以便提高手术的安全性。方法 游离系膜后,钳夹下将切除肠段的下端先切断,将其近侧端置入并固定于粘附在手术床边的塑料袋中;松开肠钳,肠内容物自由流入袋内;双手交替推挤膨胀的肠段,由近而远,由小肠至大肠,直至大、小肠的内容物彻底排空。钳夹下切除上端,移除切下的肠段和充满粪便的塑料袋。结果 使用本法行肠减压术,一期切除的左半结肠癌和各类小肠急性梗阻,均未发生吻合口漏和腹腔污染。结论 本法可推荐为术中肠减压的首选方法。     

关节成形术中细菌污染观察

目的通过关节成形术中收集的标本进行细菌学检查,评估手术区域的污染情况,确定微生物的种属,明确污染的途径,为临床手术过程的无菌术改进提供依据,以降低感染率.方法从80例髋、膝关节成形术中收集的标本进行细菌培养.结果吸管尖部污染率为17.1%,手术灯把手为12.7%,皮刀为10.8%,深部刀片为4.0%,准备手术过程中所戴手套尖部31.3%被污染,术中收集袋中的注射器22.9%培养出细菌,手术结束时的手术衣前部18.9%被污染,8.8%的筋膜缝合针有污染.78%的微生物为金黄色葡萄球菌.两年后的随访中,发现一例深部感染,证实为葡萄球菌感染.结论关节成形手术中所用物品可污染细菌,临床实践中应加以注意并进行改进.     

Prophylactic antibiotherapy in abdominal surgery. First- vs third-generation cephalosporins

To compare the efficiency of antibioprophylaxis by cefazolin sodium or cefotaxime sodium, 3137 consecutive patients undergoing abdominal surgery were included in a prospective, randomized, controlled, multicenter study. The patients were divided into four strata, according to the degree of contamination during the operation and the risk factors. Within each stratum, the patients were randomized into three groups of treatment: (1) cefazolin, (2) cefotaxime, and (3) nontreatment (control). Antibiotics were administered perioperatively in three intravenous doses of 1 g at eight-hour intervals. Patients undergoing colon surgery or with peritonitis at the time of the operation were excluded from the study. The wound abscess rate was significantly lower in the treated groups than in the control group, except in stratum 3 (contaminated surgery). The percentage of postoperative peritonitis was twice as low in the treated groups as in the control group. There was no difference between the groups receiving cefazolin or cefotaxime. The patients in the treated groups received significantly less postoperative antibiotics than the patients in the control group. In terms of cost, antibioprophylaxis by cefazolin seems to be warranted in all operations with a low anaerobic contamination.     

Risk of blood contamination and injury to operating room personnel.

The potential for transmission of deadly viral diseases to health care workers exists when contaminated blood is inoculated through injury or when blood comes in contact with nonintact skin. Operating room personnel are at particularly high risk for injury and blood contamination, but data on the specifics of which personnel are at greater risk and which practices change risk in this environment are almost nonexistent. To define these risk factors, experienced operating room nurses were employed solely to observe and record the injuries and blood contaminations that occurred during 234 operations involving 1763 personnel. Overall 118 of the operations (50%) resulted in at least one person becoming contaminated with blood. Cuts or needlestick injuries occurred in 15% of the operations. Several factors were found to significantly alter the risk of blood contamination or injury: surgical specialty, role of each person, duration of the procedure, amount of blood loss, number of needles used, and volume of irrigation fluid used. Risk calculations that use average values to include all personnel in the operating room or all operations performed substantially underestimate risk for surgeons and first assistants, who accounted for 81% of all body contamination and 65% of the injuries. The area of the body contaminated also changed with the surgical specialty. These data should help define more appropriate protection for individuals in the operating room and should allow refinements of practices and techniques to decrease injury.     

Bacterial contamination of femoral head allografts from living donors

We analyzed the bacterial contamination rate of femoral head allografts from living donors and determined the true bacterial load with cultures from the grafts in their entirety in a specially prepared medium. During 4 years we took swab cultures from 2,679 grafts of which 2,414 (90%) were negative. In a period of 12 months, grafts rejected for reasons other than infectious disease were cultured in their entirety to determine the true bacterial load. Of the 106 grafts included, 15 were contaminated. Microorganisms were isolated from 10 of the 91 initially swab culturenegative grafts (9%) and from only 5 of the 15 swab culture-positive grafts, most of which were normal skin contaminants. Swab culture negative grafts apparently may still be contaminated. It seems wise to subject all femoral head allografts from living donors to antibacterial processing.