Surgical Space Suits Increase Particle and Microbiological Emission Rates in a Simulated Surgical Environment.

BACKGROUND: The role of space suits in the prevention of orthopedic prosthetic joint infection remains unclear. Recent evidence suggests that space suits may in fact contribute to increased infection rates, with bioaerosol emissions from space suits identified as a potential cause. This study aimed to compare the particle and microbiological emission rates (PER and MER) of space suits and standard surgical clothing. METHODS: A comparison of emission rates between space suits and standard surgical clothing was performed in a simulated surgical environment during 5 separate experiments. Particle counts were analyzed with 2 separate particle counters capable of detecting particles between 0.1 and 20 µm. An Andersen impactor was used to sample bacteria, with culture counts performed at 24 and 48 hours. RESULTS: Four experiments consistently showed statistically significant increases in both PER and MER when space suits are used compared with standard surgical clothing. One experiment showed inconsistent results, with a trend toward increases in both PER and MER when space suits are used compared with standard surgical clothing. CONCLUSION: Space suits cause increased PER and MER compared with standard surgical clothing. This finding provides mechanistic evidence to support the increased prosthetic joint infection rates observed in clinical studies.

Healthcare-Associated Mycobacterium chimaera Infection Subsequent to Heater-Cooler Device Exposure During Cardiac Surgery.

A SERIES of reports in the United States and Europe have linked Mycobacterium chimaera infections to contaminated heater-cooler devices used during cardiac surgery. Heater-cooler devices commonly are used for cardiopulmonary bypass during cardiac surgery. M. chimaera is a slow-growing nontuberculous mycobacterium that has been shown to cause cardiac complications that can lead to fatal disease following cardiac surgery. Given that more than 250,000 cardiothoracic surgical procedures requiring cardiopulmonary bypass take place each year in the United States, the estimated number of patient exposures to M. chimaera has prompted a public health crisis. The goal of this review is to summarize the present status of the M. chimaera outbreak and provide cardiothoracic surgeons, cardiac anesthesiologists, and other clinicians with current approaches to patient management and to discuss risk mitigation.

The Shift of an Intestinal "Microbiome" to a "Pathobiome" Governs the Course and Outcome of Sepsis Following Surgical Injury.

Sepsis following surgical injury remains a growing and worrisome problem following both emergent and elective surgery. Although early resuscitation efforts and prompt antibiotic therapy have improved outcomes in the first 24 to 48  h, late onset sepsis is now the most common cause of death in modern intensive care units. This time shift may be, in part, a result of prolonged exposure of the host to the stressors of critical illness which, over time, erode the health promoting intestinal microbiota and allow for virulent pathogens to predominate. Colonizing pathogens can then subvert the immune system and contribute to the deterioration of the host response. Here, we posit that novel approaches integrating the molecular, ecological, and evolutionary dynamics of the evolving gut microbiome/pathobiome during critical illness are needed to understand and prevent the late onset sepsis that develops following prolonged critical illness.

Quantification Analysis of the Intraoperative Bacterial Contamination Rate and Level in Osteochondral Autografts.

BACKGROUND: Inadvertent contamination of osteochondral (OC) autografts during harvesting and preparation can lead to significant complications and can cause the operating team to weigh the infection risk after reimplantation against discarding the OC fragment. The most commonly reported contamination mechanism is the accidental dropping of an OC fragment; however, associated contamination levels remain unclear. The rate and level of contamination during standard harvesting and preparation are also unknown. PURPOSE: To quantitatively evaluate the rate and level of bacterial contamination of OC autografts during harvesting and preparation compared with those of accidently dropped autografts. STUDY DESIGN: Controlled laboratory study. METHODS: Under sterile conditions, 138 fresh OC specimens were harvested and retrieved from 23 primary total knee arthroplasties (TKAs). Six OC fragments were retrieved from each TKA: 3 were used as controls, and 3 were dropped onto the operating room floor. Each specimen was incubated to allow for aerobic and anaerobic growth, and the number of colony-forming units (CFUs) per gram was calculated. RESULTS: Contamination rates (positive cultures) for the control and dropped groups were 29% (n = 20/69) and 42% (n = 29/69), respectively. The difference in the contamination rate between groups was not statistically significant (P = .109). The most common organisms identified were Staphylococcus aureus (40%) in the control group and Staphylococcus epidermidis (24.1%) and Bacillus species (20.7%) in the dropped group. The contamination level (CFUs/g) for both groups was low. The median (range) CFUs/g among the contaminated specimens in the dropped and control groups were 27 (1-120) and 3 (1-15), respectively (P < .0001). CONCLUSION: A relatively high rate of OC autograft contamination can be expected during harvesting and preparation (29%) or after accidentally dropping a specimen (42%). Although the types of organisms isolated differed between specimens contaminated during harvesting and preparation and dropped specimens, the quantification of the autograft contamination level revealed a very low CFUs/g in both cases. CLINICAL RELEVANCE: The intraoperative autograft contamination level is very low. Hence, in cases of grafts with a known contamination incident, saving and reimplanting them after proper decontamination is recommended over discarding them or using an allograft.

Do 'Surgical Helmet Systems' or 'Body Exhaust Suits' Affect Contamination and Deep Infection Rates in Arthroplasty? A Systematic Review.

This systematic review examined whether negative-pressure Charnley-type body exhaust suits (BES) or modern positive-pressure surgical helmet systems (SHS) reduce deep infection rates and/or contamination in arthroplasty. For deep infection, four studies (3990 patients) gave adjusted relative risk for deep infection of 0.11 (P = 0.09) against SHS. Five of 7 (71%) studies found less air contamination and 2 of 4 studies (50%) less wound contamination with BES. One of 4 (25%) found less air contamination with SHS and 0 of 1 (0%) less wound contamination. In contrast to BES, modern SHS designs were not shown to reduce contamination or deep infection during arthroplasty.

A novel technique to prevent endobronchial spillage during video assisted thoracoscopic lobectomy.

Endobronchial spillage of fungal material into normal lung can infect it and the spillage of fungal material should be prevented during surgery. We report our experience of a patient who presented for right upper lobectomy with bronchiectasis, tubercular destruction and subsequent aspergilloma. A 4F Fogarty catheter was introduced through the tracheal lumen of the left sided endobronchial double lumen tube (DLT) to occlude the bronchus intermedius to prevent spillage of aspergilloma into the non-infected lower and middle lobes of the right lung. The Fogarty catheter was pulled into the trachea just before stapling the bronchus; thereafter, right upper lobectomy was completed successfully. The patient was extubated uneventfully and transferred to post-operative recovery ward. The endobronchial blockage of the intermediate bronchus of the operative lung by the Fogarty catheter and isolation of the left lung by the DLT prevented spillage of aspergilloma in both the operative right lung and the left lung.

Intraoperative contamination and space suits: a potential mechanism.

The body exhaust suit (BES) of Charnley creates 'negative pressure' inside the gown using intake/outtake tubing. Modern 'space suit' (SS) systems incorporate helmet-based intake fans, which use the hood material as a filter and create 'positive pressure' inside the gown. While early studies of BES demonstrate a clear reduction in infection rates following arthroplasty, recent clinical data on SS use has paradoxically reported a marked increase. We hypothesized that the positive pressure inside the gown could carry air and particles via the unsealed area around the surgeon's cuff into the operative field. We performed 12 simulated operations with the surgeons hands covered in fluorescent 0.5 micron powder that approximates the size of shedded skin squames. Photographs under UV light and air particle counts were used to compare potential contamination rates between SS and conventional gowns using a standardised scoring system. The highest powder migration was seen in the SS group with a score of 15.3 out of 28. No powder migration was seen in the standard gown group (p = 0.028). This study provides a plausible explanation for the increase in infection rates seen with SS use. We recommend SS be considered for personal protection only and supplemented with sealant tape around the inner glove.

Rectocutaneous fistula and nonunion after TranS1 axial lumbar interbody fusion L5-S1 fixation: case report.

The authors report a case of rectal injury, rectocutaneous fistula, and pseudarthrosis after a TranS1 axial lumbar interbody fusion (AxiaLIF) L5-S1 fixation. The TranS1 AxiaLIF procedure is a percutaneous minimally invasive approach to transsacral fusion of the L4-S1 vertebral levels. It is gaining popularity due to the ease of access to the sacrum through the presacral space, which is relatively free from intraabdominal and neurovascular structures. This 35-year-old man had undergone the procedure for the treatment of degenerative disc disease. The patient subsequently presented with fever, syncope, and foul-smelling gas and bloody drainage from the surgical site. A CT fistulagram and flexible sigmoidoscopy showed evidence of rectocutaneous fistula, which was managed with intravenous antibiotic therapy and bowel rest with total parenteral nutrition. Subsequent studies performed 6 months postoperatively revealed evidence of pseudarthrosis. The patient's rectocutaneous fistula symptoms gradually subsided, but his preoperative back pain recurred prompting a revision of his L5-S1 spinal fusion.

Reduction in intraoperative bacterial contamination of peripheral intravenous tubing through the use of a novel device.

BACKGROUND: Hand hygiene is a vital intervention to reduce health-care associated infections, but compliance remains low. The authors hypothesized that improvements in intraoperative hand hygiene compliance would reduce transmission of bacteria to surgical patients and reduce the incidence of postsurgical healthcare-associated infections. METHODS: The authors performed a controlled before-and-after study over 2 consecutive months. One hundred fourteen operative cases were enrolled. Two predesignated sites on the anesthesia machine were selected, decontaminated, and cultured via aseptic technique. These sites and the peripheral intravenous stopcock were cultured again after completion of the surgery. The treatment phase used a novel personal hand-decontamination device capable of recording hand-decontamination events. RESULTS: There were no significant differences in patient location, age, or case duration and procedure type between groups. Use of the Sprixx GJ device (Harbor Medical Inc., Santa Barbara, CA) increased hourly hand decontamination events by 27-fold as compared with baseline rates (P < 0.002; 95% confidence interval, 3.3-13.4). Use of the device was associated with a reduction in contamination in the anesthesia work area and peripheral intravenous tubing. Intravenous tubing contamination was identified in 32.8% of cases in the control group versus 7.5% in the treatment group (odds ratio, 0.17; 95% confidence interval, 0.06-0.51; P < 0.01). Healthcare-associated infections rates were reduced in the device group (3.8%) as compared with the control group (17.2%) (odds ratio, 0.19; 95% confidence interval, 0.00-0.81; P = 0.02). CONCLUSIONS: Improved hand hygiene compliance through the use of a novel hand sanitation strategy reduces the risk of intraoperative bacterial transmission. The intervention was associated with a reduction in healthcare-associated infections.

Sterility of C-arm fluoroscopy during spinal surgery.

STUDY DESIGN: Prospective study evaluating the sterility of 25 C-arm drapes after their use during spine surgery. OBJECTIVE: To use swab samples to evaluate the sterility of draped C-arms at the end of spine surgical cases and assess the integrity of the sterile technique. SUMMARY OF BACKGROUND DATA: Intraoperative fluoroscopy is used routinely in the operating room for a variety of spinal applications. Although the C-arm may help the surgeon assess spinal alignment and facilitate the placement of instrumentation, there are concerns that the C-arm may represent a potential source of contamination and increase the risk of developing a postoperative infection. METHODS.: This study included 25 surgical cases requiring a standard fluoroscopic C-arm that were performed by 2 spine surgeons. Sterile culture swabs were used to obtain samples from 5 defined locations on the C-arm drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control and an additional 25 C-arm drapes were swabbed immediately after they were applied to the C-arm unit in order to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. RESULTS: Contamination was noted on only 1 of 25 negative control drapes at a single location (4%). One hundred percent and 96% of the positive control swabs that were obtained from the negative controls and postoperative drapes exhibited growth, respectively. Although at least some degree of contamination was observed at all locations of the C-arm drape after surgery, the upper 2 sample sites demonstrated the greatest degree of contamination; the incidences of postoperative contamination were significantly greater for the top (56%, P < 0.000001) and upper front of the receiver (28%, P = 0.010) compared to the negative controls. In contrast, the lower front, receiver plate, and midportion of the C-arm were associated with lower rates of contamination (12%-20%). CONCLUSION: The upper portions of the C-arm clearly exhibited the greatest rates of contamination during spinal operations. This contamination most likely occurs when the undraped portions of the C-arm are rotated to acquire lateral images. As a result, we no longer consider the top portion of the C-arm drape to be sterile in these situations and we believe that avoiding contact with these areas may decrease the risks of intraoperative contamination and possibly postoperative infection as well.

Microbiologic and histologic assessment of intentional bacterial contamination of bone grafts.

PURPOSE: The purpose of this study was to investigate methods of removing pathogenic micro-organisms from bone grafts that have been contaminated during surgery. MATERIALS AND METHODS: Femora were removed from Sprague-Dawley rats and were divided into sections and contaminated in solutions of the bacteria Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Contaminated bone specimens in each group were immersed in various solutions for specified periods so their antibacterial effects could be evaluated. After these procedures were performed, bone specimens were cultured in nutrient media. Bone structure was evaluated, and the appropriate decontamination method was selected. RESULTS: Solutions such as povidone-iodine, neomycin, cephazolin sodium, and rifamycin were found to be effective decontaminants. These solutions did not damage the bone structure. Among these solutions, only rifamycin was effective against all bacteria used in this study to contaminate bone grafts. CONCLUSIONS: Rifamycin seems to be the most suitable agent for the elimination of contamination introduced into bone grafts during surgery.

Intraoperative contamination influences wound discharge and periprosthetic infection.

Intraoperative bacterial contamination increases risk for postoperative wound-healing problems and periprosthetic infection, but to what extent remains unclear. We asked whether bacterial contamination of the instruments and bone during primary prosthesis insertion was associated with prolonged wound discharge and subsequent periprosthetic infection. During 100 total hip arthroplasties, four intraoperative cultures were taken from the instruments and two portions of removed bone. Postoperatively, the duration of wound discharge was monitored, with Day 5 as the cut-off point. All patients were followed for 2 years to determine whether periprosthetic infection occurred. Bacterial contamination occurred in 36 operative procedures (36%). We found an association between intraoperative contamination and prolonged wound discharge, with a relative risk of 2.5. The culturing of removed bone had a positive predictive value of 81% to 90%. Other factors associated with prolonged wound discharge were rheumatoid arthritis (relative risk, 6.4), use of cement (relative risk, 1.6), and increased blood loss (relative risk, 1.5).

Investigation of bacteremia following nasotracheal intubation.

BACKGROUND: The aim of this study was to detect the risk of bacteremia from nasotracheal intubation in children undergoing dental treatment under general anesthesia. METHODS: Two 10 ml blood samples were taken, the first as a baseline and the second within 30 s following the nasotracheal intubation. The samples were inoculated into 5 ml aerobic and 5 ml anaerobic blood culture bottles. Following incubation in an automated blood culture system, bacteria were identified by using conventional biochemical methods and commercial identification systems. Mc Nemar's test was used to assess the findings statistically. RESULTS: Of 74 patients only nine (12.3%) had positive blood cultures after the intubation and seven of these had been intubated without trauma. The incidence of bacteremia was significantly higher after atraumatic intubation (7/9) compared with traumatic intubation (2/9) (P < 0.05). The most common bacteria in positive cultures were Streptococcus viridans, four of 74 (5.4%). CONCLUSIONS: Since the occurrence of bacteremia after nasotracheal intubation is hazardous for patients at risk for developing infective endocarditis, to prevent further complications prophylactic antibiotic treatment is recommended.

Asymptomatic bacteriuria: when to screen and when to treat.

Asymptomatic bacteriuria is common. Populations with structural or functional abnormalities of the genitourinary tract may have an exceedingly high prevalence of bacteriuria, but even healthy individuals frequently have positive urine cultures. Asymptomatic bacteriuria is seldom associated with adverse outcomes. Pregnant women and individuals who are to undergo traumatic genitourinary interventions are at risk for complications of bacteriuria and benefit from screening and treatment programs. Although screening is recommended for renal transplant recipients, the benefits for these patients are less clear. For other populations, including most bacteriuric individuals, negative outcomes attributable to asymptomatic bacteriuria have not been described. Treatment of asymptomatic bacteriuria in these patients is not beneficial and, in fact, may be associated with harmful outcomes, such as increased short-term frequency of symptomatic infection, adverse drug effects, and reinfection with organisms of increased antimicrobial resistance. Screening for asymptomatic bacteriuria and treatment is recommended for only selected groups where benefit has been shown. Many research questions still need to be addressed. Different populations have unique risk factors, and the benefits and risks of different management approaches for asymptomatic bacteriuria must continue to be addressed systematically in appropriate clinical trials.

Microbial contamination of the anterior chamber during phacoemulsification.

PURPOSE: To study the nature and frequency of anterior chamber contamination during phacoemulsification. SETTING: Department of Ophthalmology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India. METHODS: Eighty eyes of 80 patients having routine phacoemulsification cataract surgery were recruited into this prospective study. Bacterial cultures from the intraoperative anterior chamber aspirates from the patients were assessed. RESULTS: Anterior chamber fluid aspirates were positive for bacteria in 37 eyes (46.25%). Coagulase-negative Staphylococcus was the most common aerobe and Propionibacterium acnes, the most common anaerobe. CONCLUSION: Results indicate that phacoemulsification has no proven advantage over conventional extracapsular cataract extraction in reducing intraoperative bacterial contamination.