The incidence of bacteraemia associated with tracheal intubation

Microbiological comparison of the disinfecting efficacy of small and large cotton swabs in nasotracheal intubation: a randomized trial

BACKGROUND

Nasotracheal intubation (NTI) is necessary during surgeries requiring clear access to the surgical field and in patients with respiratory issues. This study investigates the pre-NTI nasal disinfection efficacy of different cotton swab sizes, hypothesizing that smaller swabs could minimize bleeding while maintaining disinfection efficacy.

METHODS

Patients classified as American Society of Anesthesiologists-physical status (ASA-PS) class 1 or 2 scheduled for general anesthesia with NTI were randomly assigned to either a large cotton swabs (LCS) or fine cotton swabs (FCS) group in this randomized controlled trial (RCT)." After anesthesia, a fine cotton swab was inserted into the inferior nasal meatus in both groups to collect bacteria (sample A). Next, the nasal cavity was disinfected with LCS or FCS according to the patient group. Bacteria were collected by inserting a fine cotton swab into the inferior nasal meatus (sample B). After surgery, bacteria were collected from the endotracheal tube tip using a fine cotton swab in both groups (sample C). The samples were cultured for 24 hours, and the colonies from samples A-C were counted. The changes in bacteria count between samples A and B and samples A and C were determined. Nasal bleeding from cotton swab insertion was assessed as a secondary outcome. Student's t-tests, a chi-square independence test, and Mann-Whitney U tests were used for the statistical analysis. The statistical significance level was set at p < 0.05.

RESULTS

Between samples A and B, the change in bacteria count was 7.2% (1.4-26.1%) (median[interquartile range]) in the LCS group and 6.9% (0.9-22%) in the FCS group (p = 0.90). Between samples A and C, the change in bacteria count was 7.5% (0.2-44%) in the LCS group and 8.3% (0.3-39%) in the FCS group (p = 0.55). We examined 62 subjects in each group (LCS and FCS), and samples A, B, and C were collected from all participants in both groups. Nasal bleeding occurred in 42/62 in the LCS group and 22/62 in the FCS group (p < 0.01).

CONCLUSION

Cotton swab thickness did not impact disinfection efficacy, but large swabs increased the risk of nasal bleeding. We recommend FCS for nasal disinfection prior to NTI in ASA 1-2 patients, as they reduce bleeding risk without compromising disinfection.

TRIAL REGISTRATION

UMIN-CTR (registration no. UMIN000051495), June 30, 2023.

Infection of Transcatheter Valvular Devices

PURPOSE OF REVIEW

This review explores the epidemiology, clinical traits, and diagnosis of Transcatheter Aortic Valve Replacement-Associated Infective Endocarditis (TAVR-IE) and mitral transcatheter edge-to-edge repair infective endocarditis (TEER-IE), focusing on a multimodal imaging approach. It addresses the rising prevalence of TAVR and TEER, emphasizing the need to understand long-term complications and clinical consequences, which poses significant challenges despite advancements in valve technology.

RECENT FINDINGS

Studies report a variable incidence of TAVR-IE and TEER-IE influenced by diverse patient risk profiles and procedural factors. Younger age, male gender, and certain comorbidities emerge as patient-related risk factors. Procedure-related factors include intervention location, valve type, and technical aspects. Microbiologically, Staphylococcus aureus, Viridans Group Streptococcus, and Enterococcus are frequently encountered pathogens. TAVR-IE and TEER-IE diagnosis involves a multimodal imaging approach due to limitations in echocardiography. Blood cultures and imaging aid identification, with Fluorescence in situ hybridization is showing promise. Treatment encompasses medical management with antibiotics and, when necessary, surgical intervention. The management approach requires a multidisciplinary "Endocarditis Team." This review underscores the need for continued research to refine risk prediction, enhance diagnostic accuracy, and optimize management strategies for TAVR-IE, considering the evolving landscape of transcatheter interventions.

Infective Endocarditis after Transcatheter Aortic Valve Replacement: Challenges in the Diagnosis and Management

Although initially conceived for high-risk patients who are ineligible for surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR) is now recommended in a wider spectrum of indications, including among young patients. However, similar to SAVR, TAVR is also associated with a risk of infectious complications, namely, prosthetic valve endocarditis (PVE). As the number of performed TAVR procedures increases, and despite the low incidence of PVE post-TAVR, clinicians should be familiar with its associated risk factors and clinical presentation. Whereas the diagnosis of native valve endocarditis can be achieved straightforwardly by applying the modified Duke criteria, the diagnosis of PVE is more challenging given its atypical symptoms, the lower sensitivity of the criteria involved, and the low diagnostic yield of conventional echocardiography. Delay in proper management can be associated with increased morbidity and mortality. Therefore, clinicians should have a high index of suspicion and initiate proper work-up according to the severity of the illness, the underlying host, and the local epidemiology of the causative organisms. The most common causative pathogens are Gram-positive bacteria such as Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus spp., and Streptococcus spp. (particularly the viridans group), while less-likely causative pathogens include Gram-negative and fungal pathogens. The high prevalence of antimicrobial resistance complicates the choice of therapy. There remain controversies regarding the optimal management strategies including indications for surgical interventions. Surgical assessment is recommended early in the course of illness and surgical intervention should be considered in selected patients. As in other PVE, the duration of therapy depends on the isolated pathogen, the host, and the clinical response. Since TAVR is a relatively new procedure, the outcome of TAVR-PVE is yet to be fully understood.

Screening of MRSA colonization in patients undergoing total joint arthroplasty

Background

Periprosthetic infection is commonly caused by Staphylococcus aureus and, if resistant to methicillin (MRSA), is associated with increase in severity and costs to patient and healthcare systems. MRSA colonizes 1-5% of the population, therefore using a screening and decolonisation protocol the risk of periprosthetic infection could be reduced. The objective of our study is to report the results of a preoperative MRSA screening and management protocol utilised at our hospital.

Methods

All patients undergoing a total joint arthroplasty at our hospital were preoperatively screened for MRSA colonization with swab samples of five different locations. Exposure to risk factors were investigated in colonised patients and they were treated for 5 days prior surgery with nasal mupirocin, chlorhexidine sponges and oral tablets.

Results

During the 48 months of the study, MRSA colonisation was identified in 22 (1.01%) of 2188 patients operated. The culture was positive only in the nasal swab in 55 patients. In five patients the nasal culture was negative, but they had another positive swab culture (three in the groin and two perianal). None of the patients reported a history of recent antibiotic treatment or hospitalization.

Conclusion

At our institution, the prevalence of MRSA colonisation is 1.01% in patients undergoing hip and knee arthroplasty. Interestingly, our screening protocol included samples from five different anatomic locations, and it is important to highlight that we found patients with negative nares culture and positive cultures in other locations. Therefore, the number of carriers may be underdiagnosed if only nasal samples are obtained.

Level of evidence

IV.

Evaluation of Antibiotic Resistance Pattern in Dental Bacteremia Detected by Multiplex PCR Technique

The aim of this study was to detect oral bacteremia and offer the antibiotic resistance patterns. Bacterial resistance pattern was evaluated in 50 patients. A spectrophotometer device equipped with UV and electrophoresis of the extracted samples on agarose gel for antibiogram test were used. PCR test 15 minutes after tooth extraction showed that bacterial strains were extracted from 16 patients. Lactobacillus, Enterococcus faecalis (E. faecalis), Streptococcus sanguinis (S. sanguinis), Streptococcus salivarius (S. salivarius), and Streptococcus mutans (S. mutans) were extracted from 5, 4, 4, 4, and 6 patients. 100% of Lactobacillus, E. faecalis, S. sanguinis, S. salivarius, and S. mutans were sensitive to tigecycline. Most of the Lactobacillus antibiotic resistance was against tetracycline and ciprofloxacin. Antibiotic resistance in S. salivarius was observed in 75% of the cases against piperacillin-tazobactam, ciprofloxacin, and cefotaxime, while in S. mutans was 84% of the cases against ceftriaxone. The results of the current study showed that tooth extraction causes bacteremia before, during, and after tooth extraction. Generally, the highest antibiotic resistance occurred against tetracycline, ciprofloxacin, and ampicillin-sulbactam. In most cases, the bacteria showed partial resistance to these antibiotics; however, tigecycline showed 100% efficacy on all types of bacteria. Streptococcus strains (salivarius, mutans, and sanguinis) were sensitive to most of the antibiotics while antibiotic sensitivity was less evident in Lactobacillus and E. faecalis. Antibiotic resistance has become a critical issue, since it leads to treatment failure when there is a need for antibiotic therapy.

Infective Endocarditis After Transcatheter Versus Surgical Aortic Valve Replacement: A Meta-Analysis

We determined the incidence, clinical characteristics, and risk factors of post-transcatheter aortic valve replacement (TAVR)-associated infective endocarditis (IE). We compared the incidence of IE after TAVR versus after surgical aortic valve replacement (SAVR). The incidence rate of IE 1-year post-TAVR was 0.9% (95% confidence interval [CI]: 0.8-1.0). Transcatheter aortic valve replacement was associated with significantly reduced IE incidence (incidence rate ratio: 0.69, 95% CI: 0.52-0.92, P = .011) compared with SAVR. In patients with TAVR IE, the pooled in-hospital mortality was 37.8% (95% CI: 32.4-43.3, I ² = 54.9%). Pooled adjusted hazard ratio (HR) revealed that peri-procedural peripheral artery disease (HR: 4.02, 95% CI: 2.28-7.10, P < .0001), moderate or severe residual aortic regurgitation (HR: 2.34, 95% CI: 1.53-3.59, P < .0001), orotracheal intubation (HR: 2.13, 95% CI: 1.19-3.82, P = .011), and male gender (HR: 1.70, 95% CI: 1.47-1.97, P < .0001) were risk factors for post-TAVR IE. Post-TAVR IE is a life-threatening complication often resulting in in-hospital mortality. The current evidence-based meta-analysis to identify risk factors may lead to the development of effective preventive and therapeutic strategies for post-TAVR IE to ultimately improve patient outcomes.

Multiplex polymerase chain reaction for detection of bacteremia during dental extraction

AIM

Incidence of transient bacteremia following dental extractions ranges 30%-70% among adults and 58%-100% in children. This study aims to assess the multiplex polymerase chain reaction (PCR) technique in detection of transient bacteremia during dental extraction.

METHODS

Twenty volunteers for dental extraction entered the study. Blood samples were taken at baseline and 30 seconds and 15 minutes after extraction. Five types of bacteria were selected, namely Streptococcus mutans, S. salivarius, S. sanguinis, Enterococcus faecalis and Lactobacillus. Blood samples were evaluated by microbial culture and multiplex PCR.

RESULTS

Blood culture showed rates of 0%, 80% and 25% for bacteremia before, during and after dental extraction, respectively. A significant difference was observed between baseline and during extraction. Using PCR, bacteremia was deemed 20%, 100% and 30% before, during and after extraction, respectively, and a significant difference was witnessed between the baseline and during extraction. The highest incidence was at the 30-second mark after extraction, and the most prevalent type of bacteria was S. mutans.

CONCLUSIONS

Multiplex PCR can be used to determine bacterial diversity with high accuracy during occurrence of bacteremia. Therefore, in cases where positive blood cultures only indicate the presence of one species, we recommend the use of this method to detect more diverse bacteria types.

Retropharyngeal Dissection by Parker Flex-Tip Nasal Endotracheal Tube

Possible complications of nasotracheal intubation include injury to the nasal or pharyngeal mucosa. Dissection of the retropharyngeal tissue by the endotracheal tube is one of the rarer of the more severe complications. Previous studies have indicated that the Parker Flex-Tip (PFT) tracheal tube (Parker Medical, Highlands Ranch, Colo) reduces the incidence of mucosal injury. We experienced a case involving inadvertent retropharyngeal placement of a PFT tube in a 29-year-old patient during nasotracheal intubation under general anesthesia for elective dental treatment. Despite thermosoftening the PFT tube, expanding the nasal meatus, and ensuring gentle maneuvering, the tube intruded into the left retropharyngeal mucosa. However, the injury was not severe, and the only required treatment was the administration of antibiotics and corticosteroids. Even when a PFT tube is utilized, pharyngeal dissection is possible. When resistance is felt during passing of the PFT tube through the nasopharynx, an alternative method to overcome this resistance should be utilized.

Risk of Surgical Site Infection in Elective Hip and Knee Replacements After Confirmed Eradication of MRSA in Chronic Carriers

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is globally endemic and is a leading cause of surgical site infection (SSI). The purpose of this study was to evaluate the incidence of SSI in MRSA carriers undergoing elective hip or knee arthroplasty, who had confirmed eradication and to compare it with incidence of SSI in non-MRSA carriers.

METHODS

This is a retrospective analysis of 6613 patients who underwent elective total hip arthroplasty (THA; n = 3347) and total knee arthroplasty (TKA; n = 3266) at our institution. A cohort of patients who were preoperatively colonized with MRSA was identified. We compared the infection rates with non-MRSA carriers.

RESULTS

We had a colonization rate of 1.3% (83 patients). A total of 79 patients had confirmed eradication of carrier status before surgical intervention. Of these, 38 were THAs and 41 were TKAs. Five of 79 patients (6.32%; 95% confidence interval [CI]: 2.35%-14.79%) had "deep SSI" within 1 year of surgery. There were 2 MRSA infections in THAs (relative risk 4.46; 95% CI: 1.12-17.82). There were 2 MRSA and 1 methicillin-sensitive Staphylococcus aureus infections in TKAs (relative risk 5.61; 95% CI: 1.81-17.38). A significant statistical difference in infection rates from MRSA negative control group was noted, which had a deep sepsis rate of 1.17% in THAs and 1.3% in TKAs over the same period.

CONCLUSION

In spite of a selective treatment program for carriers and confirmed eradication, there is still a significantly increased risk of SSI in MRSA-colonized patients undergoing hip or knee arthroplasties.

Predictors of Staphylococcus aureus Colonization and Results after Decolonization

Protocols for the screening and decolonization of Staphylococcus aureus prior to total joint arthroplasty (TJA) have become widely adopted. The goals of this study were to determine: (1) whether implementation of a screening protocol followed by decolonization with mupirocin/vancomycin and chlorhexidine reduces the risk of revision compared with no screening protocol (i.e., chlorhexidine alone) and (2) whether clinical criteria could reliably predict colonization with MSSA and/or MRSA. Electronic medical records of primary patients undergoing TJA that were screened (n = 3,927) and were not screened (n = 1,751) for Staphylococcus aureus at least 4 days prior to surgery, respectively, were retrospectively reviewed. All patients received chlorhexidine body wipes preoperatively. Patients carrying MSSA and MRSA were treated preoperatively with mupirocin and vancomycin, respectively, along with the standard preoperative antibiotics and chlorhexidine body wipes. Screened patients were 50% less likely to require revision due to prosthetic joint infection compared to those not screened (p = 0.04). Multivariate regression models were poorly accurate in predicting colonization with MSSA (AUC = 0.58) and MRSA (AUC = 0.62). These results support the routine screening and decolonization of S. aureus prior to TJA.

Intravenous amoxicillin/clavulanate for the prevention of bacteraemia following dental procedures: a randomized clinical trial

OBJECTIVES

Although controversy exists regarding the efficacy of antibiotic prophylaxis for patients at risk of infective endocarditis, expert committees continue to publish recommendations for antibiotic prophylaxis regimens. This study aimed to evaluate the efficacy of four antimicrobial regimens for the prevention of bacteraemia following dental extractions.

METHODS

The study population included 266 adults requiring dental extractions who were randomly assigned to the following five groups: control (no prophylaxis); 1000/200 mg of amoxicillin/clavulanate intravenously; 2 g of amoxicillin by mouth; 600 mg of clindamycin by mouth; and 600 mg of azithromycin by mouth. Venous blood samples were collected from each patient at baseline and at 30 s, 15 min and 1 h after dental extractions. Samples were inoculated into BACTEC Plus culture bottles and processed in the BACTEC 9240. Conventional microbiological techniques were used for subcultures and further identification of the isolated bacteria. The trial was registered at ClinicalTrials.gov with ID number NCT02115776.

RESULTS

The incidence of bacteraemia in the control, amoxicillin/clavulanate, amoxicillin, clindamycin and azithromycin groups was: 96%, 0%, 50%, 87% and 81%, respectively, at 30 s; 65%, 0%, 10%, 65% and 49% at 15 min; and 18%, 0%, 4%, 19% and 18% at 1 h. Streptococci were the most frequently identified bacteria. The percentage of positive blood cultures at 30 s post-extraction was lower in the amoxicillin/clavulanate group than in the amoxicillin group (P < 0.001). The incidence of bacteraemia in the clindamycin group was similar to that in the control group.

CONCLUSIONS

Bacteraemia following dental extractions was undetectable with amoxicillin/clavulanate prophylaxis. Alternative antimicrobial regimens should be sought for patients allergic to the β-lactams.

Infective endocarditis after transcatheter aortic valve implantation: results from a large multicenter registry

BACKGROUND

We aimed to determine the incidence, predictors, clinical characteristics, management, and outcomes of infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

This multicenter registry included 53 patients (mean age, 79±8 years; men, 57%) who suffered IE after TAVI of 7944 patients after a mean follow-up of 1.1±1.2 years (incidence, 0.67%, 0.50% within the first year after TAVI). Mean time from TAVI was 6 months (interquartile range, 1-14 months). Orotracheal intubation (hazard ratio, 3.87; 95% confidence interval, 1.55-9.64; P=0.004) and the self-expandable CoreValve system (hazard ratio, 3.12; 95% confidence interval, 1.37-7.14; P=0.007) were associated with IE (multivariate analysis including 3067 patients with individual data). The most frequent causal microorganisms were coagulase-negative staphylococci (24%), followed by Staphylococcus aureus (21%) and enterococci (21%). Vegetations were present in 77% of patients (transcatheter valve leaflets, 39%; stent frame, 17%; mitral valve, 21%). At least 1 complication of IE occurred in 87% of patients (heart failure in 68%). However, only 11% of patients underwent valve intervention (valve explantation and valve-in-valve procedure in 4 and 2 patients, respectively). The mortality rate in hospital was 47.2% and increased to 66% at the 1-year follow-up. IE complications such as heart failure (P=0.037) and septic shock (P=0.002) were associated with increased in-hospital mortality.

CONCLUSIONS

The incidence of IE at 1 year after TAVI was 0.50%, and the risk increased with the use of orotracheal intubation and a self-expandable valve system. Staphylococci and enterococci were the most common agents. Although most patients presented at least 1 complication of IE, valve intervention was performed in a minority of patients, and nearly half of the patients died during the hospitalization period.

A serious mediastinum abscess induced by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA): a case report and review of the literature

A 75-year-old man with interstitial pneumonia and enlarged mediastinal lymph nodes underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). He developed a high-grade fever seven days after EBUS-TBNA was performed; laboratory and radiologic findings showed intense inflammatory reactions, with swelling of the mediastinal lymph nodes on chest computed tomography. Mediastinal lymph node abscess was diagnosed, and it worsened in spite of systemic antibacterial treatment. Surgical treatment using a median sternotomy was performed, and the cultivation of surgically obtained mediastinal lymph node abscess fluid revealed Streptococcus intermedius. Combined treatment with antibiotics and surgical treatment was effective, leading to remission.

Detection of transient bacteraemia following dental extractions by 16S rDNA pyrosequencing: a pilot study

OBJECTIVE

The current manuscript aims to determine the prevalence, duration and bacterial diversity of bacteraemia following dental extractions using conventional culture-dependent methods and 16S rDNA pyrosequencing.

METHODS

The study group included 8 patients undergoing dental extractions under general anaesthesia. Peripheral venous blood samples were collected at baseline, 30 seconds and 15 minutes after the dental extractions. Blood samples were analysed for bacteraemia applying conventional microbiological cultures under aerobic and anaerobic conditions as well as pyrosequencing using universal bacterial primers that target the 16S ribosomal DNA gene.

RESULTS

Transient bacteremia was detected by culture-based methods in one sample at baseline time, in eight samples at 30 seconds, and in six samples at 15 minutes after surgical procedure; whereas bacteraemia was detected only in five blood samples at 30 seconds after dental extraction by using pyrosequencing. By applying conventional microbiological methods, a single microbial species was detected in six patients, and Streptococcus viridans was the most frequently cultured identified bacterium. By using pyrosequencing approaches however, the estimated blood microbial diversity after dental extractions was 13.4±1.7 bacterial families and 22.8±1.1 genera per sample.

CONCLUSION

The application of 16S rDNA pyrosequencing underestimated the prevalence and duration of bacteraemia following dental extractions, presumably due to not reaching the minimum DNA required for PCR amplification. However, this molecular technique, unlike conventional culture-dependent methods, revealed an extraordinarily high bacterial diversity of post-extraction bacteraemia. We propose that microorganisms recovered by culture may be only the tip of an iceberg of a really diverse microbiota whose viability and potential pathogenicity should be further studied.

Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures

The Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures evidence-based clinical practice guideline was codeveloped by the American Academy of Orthopaedic Surgeons (AAOS) and the American Dental Association. This guideline replaces the previous AAOS Information Statement, "Antibiotic Prophylaxis in Bacteremia in Patients With Joint Replacement," published in 2009. Based on the best current evidence and a systematic review of published studies, three recommendations have been created to guide clinical practice in the prevention of orthopaedic implant infections in patients undergoing dental procedures. The first recommendation is graded as Limited; this recommendation proposes that the practitioner consider changing the long-standing practice of routinely prescribing prophylactic antibiotic for patients with orthopaedic implants who undergo dental procedures. The second, graded as Inconclusive, addresses the use of oral topical antimicrobials in the prevention of periprosthetic joint infections. The third recommendation, a Consensus statement, addresses the maintenance of good oral hygiene.

Methicillin-resistant Staphylococcus aureus (MRSA)

Staphylococcus aureus is one of the leading causes of surgical site infection (SSI). Over the past decade there has been an increase in methicillin-resistant S. aureus (MRSA). This is a subpopulation of the bacterium with unique resistance and virulence characteristics. Nasal colonisation with either S. aureus or MRSA has been demonstrated to be an important independent risk factor associated with the increasing incidence and severity of SSI after orthopaedic surgery. Furthermore, there is an economic burden related to SSI following orthopaedic surgery, with MRSA-associated SSI leading to longer hospital stays and increased hospital costs. Although there is some controversy about the effectiveness of screening and eradication programmes, the literature suggests that patients should be screened and MRSA-positive patients treated before surgical admission in order to reduce the risk of SSI.

Cite this article: Bone Joint J 2013;95-B:4–9.

Antimicrobial prophylaxis in noncardiac prosthetic device recipients

BACKGROUND

Secondary antimicrobial prophylaxis involves the use of ≥ 1 antimicrobial agent just prior to the time when a diagnostic/therapeutic procedure, which may induce infection, is to be performed. In the context of this article, antimicrobial agent(s) are administered to patients with ≥ 1 implanted prosthetic device in order to prevent metastatic seeding of the device(s) during bacteremia induced by a diagnostic/therapeutic procedure. Antimicrobial agents used in this context are only administered periprocedurally. Secondary antimicrobial prophylaxis of endocarditis in recipients of cardiac prosthetic materials (including valves, shunts, conduits, and patches) has been reasonably well established. However, secondary antimicrobial prophylaxis in recipients of other types of prosthetic devices has been the subject of much controversy, with a wide variety of recommendations being made.

OBJECTIVES

The purpose of this article was to conduct a narrative review of the published literature on the topic of secondary antimicrobial prophylaxis in recipients of noncardiac prosthetic devices and make evidence-based recommendations for each type of device, where possible.

METHODS

Medline/PubMed and EMBASE databases were searched for English-language articles published from 1950 to the present (January 2012). Search terms included "prophylaxis," "antibiotics," "antimicrobials," "prosthetic devices," "prosthesis-related infections," "bacteremia," the names of the individual types of prosthetic devices, and the names of the individual procedures potentially inducing bacteremia. Articles dealing with any aspect relevant to this topic were eligible for review. The bibliographies of retrieved articles were also carefully scanned to identify any articles not previously identified.

RESULTS

Based on review of the available literature, secondary antimicrobial prophylaxis is justified in only a few specific circumstances. For recipients of prosthetic vascular grafts/stents, hemodialysis arteriovenous shunts, and ventriculoatrial/ventriculovenous shunts, prophylaxis is warranted during the initial 6 months, initial 6 weeks, and at all times after implantation/revision, respectively, when dental procedures capable of inducing high-level bacteremia are planned. Prosthetic joint recipients should receive prophylaxis in the following 3 circumstances: 1) patient is to undergo dental procedure(s) capable of inducing high-level bacteremia plus either the patient is still within 2 years of device implantation/revision or the patient has ≥ 1 risk factor for hematogenous prosthetic joint infection; 2) patient is to undergo genitourinary tract procedure(s) capable of inducing high-level bacteremia plus the patient has ≥ 1 risk factor for high-risk bacteriuria; and 3) patient is to undergo perforating dermatologic surgery on the oral mucosa or at skin sites at increased risk for surgical site infection plus patient has ≥ 1 risk factor for hematogenous prosthetic joint infection. The data are inadequate to justify secondary antimicrobial prophylaxis for recipients of other types of prosthetic devices. On the basis of 9 surveys of prescriber behavior, it is apparent that there exists, over a wide geographic area, a wide disconnect between clinical practice and the secondary antimicrobial prophylaxis guidelines issued by the professional organizations representing these prescribers. Antimicrobial agent overuse was especially problematic among orthopedic and colorectal surgeons, urologists, and family practitioners. Dentists and maxillofacial surgeons followed guidelines more closely.

CONCLUSION

Device-, procedure-, and patient characteristic-dependent factors elicited over many years have narrowed down the secondary antimicrobial prophylaxis recommendations for noncardiac prosthetic devices to a small number. Despite this, physician prescribers frequently do not follow prophylaxis guidelines established by their own professional organizations. Risk-benefit and cost-effectiveness studies have found that no prophylaxis is actually superior to universal prophylaxis, likely due to known antimicrobial toxicities, such as anaphylactic/anaphylactoid reactions and Clostridium difficile-associated disease. Much work remains in establishing and extending the scientific basis for secondary antimicrobial prophylaxis and transforming this knowledge into appropriate action by the clinician.

Bacteraemia following single-stage percutaneous dilatational tracheostomy

OBJECTIVE

Surgical tracheostomy in critically ill adults has largely been replaced by physicians performing percutaneous dilatational tracheostomy (PDT) at the bedside. Complications associated with this technique include haemorrhage, wound infection, barotrauma, false passage, ruptured tracheal ring and bacteraemia. Prophylactic antibiotics are not generally used with this procedure, however the incidence of bacteraemia following PDT has not been extensively studied.

DESIGN

Prospective observational study.

SETTING

Adult intensive care unit of a university medical centre.

METHODS

Peripheral venous blood cultures were obtained immediately before and after PDT in 118 consecutive patients. Surveillance cultures of potential respiratory pathogens were also recorded using routine non-directed broncholalveolar lavage.

RESULTS

Forty-three female and 75 male patients underwent PDT. Fifty-seven patients (48.3%) were not receiving antibiotics on the day of PDT, whilst the remaining 61 individuals (51.7%) were on antibiotic therapy at the time of the procedure. Bacteraemia following PDT occurred in six out of 113 patients (5.3%), five of which occurred in patients not receiving antibiotics (9.2%). Unexpected bacteraemia (positive pre-and post PDT blood cultures) was identified in five patients, two of whom were on antibiotic therapy.

CONCLUSION

The incidence of bacteraemia following a single stage PDT was similar to other manipulations of the aerodigestive tract such as intubation, insertion of an LMA or tooth brushing. We suggest that routine antibiotic prophylaxis is unnecessary for this procedure.