Vascular Surgery Ward Research Articles

The Screening of Methicillin-Resistant Staphylococcus aureus in Vascular Surgery Patients: A Comparison of Molecular Testing and Broth-Enriched Culture

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a major global health care-associated pathogen. This study sought to examine the prevalence of MRSA in patients who were admitted to a vascular surgery ward during a 3-month period. Methods: MRSA screening was accomplished through the acquisition of nasal, throat and perineal swabs. These swabs were placed in tryptic soy broth that had been supplemented with 6.5% NaCl and incubated for 24 h. The resulting isolates were subcultured on agar plates containing 5% sheep blood. The BD GeneOhm MRSA assay for screening swabs was performed in accordance with the manufacturer’s instructions. Results: A total of 58 patients were included in the study and swabs from 232 sites were obtained during the sampling period. MRSA was detected in 33 samples of 12 patients during the study period; thus, there was a 20.6% prevalence of patients who were recognized as MRSA carriers. There were discrepancies between the results of classical bacteriological screening and molecular MRSA detection methods in 8 of the patients. Conclusions: Nasal, throat and perineal MRSA screening can detect the carriage of this pathogen and allow for the timely use of appropriate infection control measures. The choice of screening techniques poses a challenge; it has been demonstrated that molecular detection methods should be performed with great sensitivity, specificity and, most importantly, speed. The cost of the PCR screening method is the only disadvantage of this approach.

Insulin Order Sets Improve Glycemic Control and Processes of Care

ObjectiveThe study objective was to evaluate the impact of a standardized preprinted subcutaneous correctional insulin order set on glycemic control, processes of care, and nursing satisfaction. MethodsThis was a controlled before/after, qualitative study using focus group interviews. The intervention group consisted of patients with diabetes who were admitted to the cardiovascular surgery ward. The control group consisted of patients with diabetes who were admitted to the vascular surgery ward. Registered nurses on the cardiovascular surgery floor participated in focus groups and completed surveys. We used a multifaceted intervention including standardized insulin order sheet, educational workshops, verbal and printed reminders, printed enabler, reference sheet, and overnight helpline. Glycemic control and hypoglycemia were assessed through chart review, and nursing satisfaction with the insulin order sets was assessed through surveys and nursing focus groups, performed before and 6 months after implementation of the insulin order set. ResultsThere was a 39% reduction in proportion of blood glucose>11.0 mmol/L (198 mg/dL) in the intervention group compared with the control group (0.17 vs 0.28, P=.03). The proportion of hypoglycemia (blood glucose<4.0 mmol/L [72 mg/dL]) was no different between the 2 groups. Nurse satisfaction increased significantly (P<.02); order sets were easy to use and improved glycemic control, processes, and efficiency of care, and reduced the number of pages between nursing and medical staff. ConclusionsStandardized insulin order sets reduced hyperglycemia and improved nursing satisfaction and processes of care. Successful implementation required stakeholder engagement, identification of barriers and facilitators in local practice, and tailoring the intervention to target these factors.

Control of an outbreak of diarrhoea in a vascular surgery unit caused by a high-level clindamycin-resistant Clostridium difficile PCR ribotype 106

This report describes an outbreak of Clostridium difficile infection (CDI) in a vascular surgery ward in 2009 caused by a high-level clindamycin-resistant ribotype 106. A case of CDI was defined as a patient with diarrhoea, positive for C.difficile toxin and negative for other enteric pathogens. Cultures were sent to the Scottish Salmonella Shigella and Clostridium difficile Reference Laboratory (SSSCDRL) for PCR ribotyping, antibiotic susceptibility testing and PCR detection of ermB. The mean age of the nine patients was 73 years (range: 38-90 years). All had received clindamycin and ciprofloxacin. All cases were typed as PCR ribotype 106 and they showed high-level resistance to clindamycin. Five of these isolates were tested by PCR for the presence of the ermB gene and no amplification was detected. This strain has rarely been isolated from patients on this ward. The outbreak was controlled successfully by closure of the ward with terminal cleaning, reinforcement of infection control precautions and the introduction of a new antibiotic policy. It is notable that this outbreak was caused by a strain with high-level clindamycin resistance not mediated by ermB. It also re-emphasizes that outbreaks of CDI can be caused by C.difficile PCR ribotypes other than 027. The outbreak was most likely associated with the use of clindamycin and ciprofloxacin cross-infection with spores in this environment. Implementation of strict infection control precautions, antimicrobial stewardship and enhanced environmental cleaning are key components in managing such an outbreak successfully. The number of meticillin-resistant Staphylococcus aureus acquisitions also fell substantially after these interventions.

Determinants of good adherence to hand hygiene among surgical health care workers

Background: Hand hygiene is the main pillar on standard precautions (hospital infection prevention), and of increasing concern. Nevertheless few is known about cognitive, attitude, perception and motivational determinants of hand hygiene’s health care workers in a surgical arena where they have never been exposed to amultimodal hand hygiene campaign. Methods: Cross-sectional study in a 900-bed university teaching hospital in Barcelona (Spain). A confidential self-administered and validated questionnaire survey was conducted in a sample of 176 surgical units’ healthcare workers (medical and nursing) before a multimodal Hand hygiene (HH) campaign started. Results: A total of 172 questionnaires were returned (response rate 97.7%), 54 (30.7%) were physicians, 75 (42.6%) were nurses and 47 (26.7%) nursing assistants. The median years of institution experience was 13.00 years (IQR 20.0), 68.8% were women, 21% were from the General Surgery ward, 21.6% were from the Urology, 39.8% from the Orthopedics and 17.6% from the Vascular Surgery ward. The self HH compliance estimated was 77.47(DE17.74), being in 107 participants (63.7%) higher than 80%. Knowledge determinants were poorly ranked as determinants of hand hygiene (OR 1.08, CI95% 1,02—1.15), while motivation to improve the hand hygiene compliance (OR 0.59, CI95% 0,39—0.88) and medical staff (OR 0.11, CI95% 0.02—0.55) or nurses (OR 0.15, CI95% 0.04—0.66) versus nursing assitants were higly ranked as determinants, independently of positive perception about hand hygiene, gender, attitude toward HH and years of institutional experience. Conclusion: In a setting of absent exposure to hand hygiene campaign, knowledge about hand hygiene, motivation and profesional status are strongly in favor of hand hygiene, rather than behavioral beliefs, independently of gender, more than 10 years of institution experience, and professional category. These results are quite different from that observed in an extensive exposure to hand hygiene campaigns where behavioral beliefs and the perception of high self-efficacy are related to hand hygiene compliance rather than reasoning. This additional insight should be considered in settings that have never been exposed to promotion activities about standard precautions.

Infections du site opératoire sur ablation de varices d’après une série continue de 408 interventions réalisées dans un centre hospitalier universitaire

Objective To determine the incidence of surgical-site infections (SSI) following varicose vein surgery in the vascular surgery ward of a French teaching hospital. Patients and methods A prospective surveillance of SSI was conducted during one year, with a 30-day postoperative follow-up. SSI cases were identified by using the definitions of the Centers for Disease Control (CDC, USA). Data acquisition and analysis were performed with the Epi-Info 6.04 software (CDC). Results Three quarters of the 408 included interventions were characterized by a NNIS score equal to 0. All patients underwent a hair removing practice before intervention. Hair removing methods were very heterogeneous and often not in accordance with national recommendations (e.g. mechanic shaving for 44.6% of patients). The incidence of SSI was 1.2% (95% confidence interval = [0.2–2.2]). All infections were identified after hospital discharge. Four infected patients out of five presented obesity or excess weight, and two patients had diabetes mellitus. The mean age of infected patients was significantly higher than non-infected ones (70.4 years versus 52.0; p < 0.01). All SSI had consequences like rehospitalization, reintervention, or antimicrobial therapy. Conclusion According to our results, SSI following varicose vein surgery are scarce and mainly concerned high-risk patients. However, in an aim of prevention, it seems necessary to homogenize hair removing methods in this ward.

Can Arteriography Serve a Diagnostic Purpose in Plaque Type VI by AHA Identification in Patients with Internal Carotid Artery Stenosis ?

Subtraction angiography is an invasive diagnostic method, which for a long time was a gold standard in carotid artery and intra-cranial vessel imaging. The aim of this research is to evaluate angiographic imaging in predicting atherosclerotic plaque type VI by AHA morphology and to assess its significance in establishing patients’ suitability for a particular operative method. Secondarily, we assessed atherosclerotic lesions in common carotid artery bifurcation. In the paper we analyzed 158 bilateral angiograms of common and internal carotid arteries in extra-and intra-cranial locations.The material consisted of patients hospitalized in the Vascular Surgery Ward of Memorial Copernicus Hospital in Lodz during 2002–2004 who underwent angiography. We concluded that: 1. In symptomatic patients irregular plaque images in subtraction angiography is correlated with plaque type VI by AHA morphology. 2. Angiography is not a sufficient method for selection of the appropriate operative treatment due to its low sensitivity and specificity in plaque morphology imaging. 3. Plaque type VI by AHA is characteristic even for the second group of carotid bifurcation stenosis (by NASCET) and it definitely dominates in group III (by NASCET).

Nosocomial spread of Pseudomonas aeruginosa producing the metallo-β-lactamase VIM-2 in a Spanish hospital: clinical and epidemiological implications

Thirty-four isolates of pan-resistant Pseudomonas aeruginosa producing VIM-2 metallo-beta-lactamase (MBL) were detected at a university hospital in Spain (July 2004-September 2006). Eleven (32%) patients had clinically significant infections, and three (27%) of these patients died. A single clone of MBL-producing P. aeruginosa was identified by pulsed-field gel electrophoresis. A cluster of isolates associated with the vascular surgery ward involved ten patients and appeared as a series of low-grade, sustained and misdiagnosed endemic infections in the hospital. The identification of MBL-positive P. aeruginosa should be considered mandatory in the surveillance of pan-resistant P. aeruginosa and requires a high index of suspicion in the context of endemic infections with a low attack rate.

P1311 Controlling an outbreak of Staphylococcus aureus in a vascular and cardiac surgery ward

P1311 Controlling an outbreak of Staphylococcus aureus in a vascular and cardiac surgery ward

Use of a temporary cohort ward as part of an intervention to reduce the incidence of meticillin-resistant Staphylococcus aureus in a vascular surgery ward

This article describes the effect of introducing a cohort area into a vascular surgery ward where a sustained increase in new cases of meticillin-resistant Staphylococcus aureus (MRSA) made the implementation of standard MRSA infection control precautions untenable. A recent review of published reports concluded, 'that little evidence could be found to suggest that isolation measures recommended in the UK are effective'. The authors recommended a reporting format to enable the evidence for isolation to be gathered more systematically. This paper follows the recommended reporting format. The setting was a 30-bedded acute and subacute vascular surgery ward within a tertiary care hospital in Glasgow, UK. The data were analysed as an interrupted time series of 19 months pre-cohort, eight months with cohort and eight months post cohort. Following the instigation of the cohort area, there was a significant reduction in the number of nosocomial MRSA isolates from patients (P=0.0005). This reduction was sustained after the cohort area was discontinued. In conclusion, effective separation of MRSA-colonized/-infected patients from patients who are not colonized/infected with MRSA, using a cohort area, resulted in a significant reduction in MRSA cross-colonization and cross-infection. The resulting reduction in MRSA prevalence within the unit facilitated effective screening and isolation of subsequent patients once the cohort area had been discontinued.

Surveillance for mupirocin resistance following introduction of routine peri-operative prophylaxis with nasal mupirocin

The authors have previously described the successful use of a five-day peri-operative prophylaxis regimen using nasal mupirocin and topical triclosan (PPNMTT) to prevent methicillin-resistant Staphylococcus aureus (MRSA) infection. The present article describes the results of repeated point-prevalence surveillance for four years to determine whether mupirocin resistance has emerged in surgical units using empirical, short-term, peri-operative prophylaxis with nasal mupirocin. Before starting PPNMTT and every six months thereafter for four years, point-prevalence surveillance was performed for nasal S. aureus carriage in all patients on five orthopaedic surgery wards, one vascular surgery ward and one elderly medicine control ward. S. aureus screening and clinical isolates (surgical patients) were undertaken for low- [minimum inhibitory concentration (MIC) 8-128 mg/L] and high-level (MIC > 128 mg/L) mupirocin resistance. All isolates were phage typed to determine whether there was evidence of the spread of clonal mupirocin-resistant strains. Of 593, 139 and 206 nasal screening swabs (taken after the regimen had started) from orthopaedic, vascular and control patients, 28%, 24% and 48% (orthopaedic/vascular surgery vs elderly medicine, P < 0.001) yielded S. aureus isolates, respectively, and 12%, 11% and 30% (P < 0.001) were MRSA positive, respectively. Of the S. aureus nasal screen isolates from orthopaedic/vascular surgery and control patients, 5% and 4%, respectively, were low-level mupirocin resistant (P > 0.1). Of 286 (orthopaedic/vascular surgery) and 68 (elderly medicine) clinical S. aureus isolates obtained after the regimen had started, 7% and 9% (P > 0.1), respectively, were low-level mupirocin resistant. No high-level mupirocin-resistant isolates were isolated from mupirocin (orthopaedic/vascular surgery) or elderly medicine control ward patients. There was no trend towards increasing prevalence of low-level mupirocin resistance during the four-year study period. The results of phage typing did not support the clonal spread of resistant strains. Long-term follow-up confirmed the efficacy of PPNMTT in reducing the prevalence of nasal carriage of S. aureus and MRSA in orthopaedic and vascular surgery patients. Despite four years of use of PPNMTT, there was no evidence of sustained emergence or spread of mupirocin resistance.

Nosocomial MRSA Infection in Vascular Surgery Patients: Impact on Patient Outcome

Although methicillin-resistant Staphylococcus aureus (MRSA) infection is a worldwide problem, data on its significance among vascular surgery patients remain scant and conflicting. This study was designed to evaluate the association between nosocomial MRSA infection and patient outcome following vascular surgery procedures. Outcomes among patients with MRSA infection were also compared to those infected with methicillin-sensitive Staphylococcus aureus (MSSA). All patients admitted to a tertiary care Vascular Surgery ward during the year 2002 were included in this retrospective review. In addition to information on demographic and comorbid conditions, data on surgical interventions, nosocomial infection incidence rates as defined by the Center for Disease Control guidelines, and MRSA screening results were collected. Primary outcome was in-hospital death. Secondary outcomes measures included length of hospital stay, readmissions, or repeat surgeries, and ICU admissions. Of a total of 408 subjects, 110 were documented with a nosocomial infection (27.0%). Of these, 16 patients (3.9%) were colonized with MRSA on screening at time of admission, 22 (5.4%) had acquired MRSA infection during hospitalization, and 15 (3.7%) had MSSA infection. Patients with MRSA, MSSA, and non-MRSA infection had similar baseline characteristics except for hypertension and tobacco use. Age and MRSA infection were significant risk factors for in-hospital deaths (OR 1.07, 95% CI 1.01-1.13, p = 0.01 and OR 7.44, 95% CI 1.63-33.9, p = 0.01, respectively). Adjusted for the effects of age, MRSA infection remained a significant independent risk factor associated with in-hospital deaths (OR 4.38, 95% CI 1.09-17.7, p = 0.04). After adjustment for baseline risk factors, MRSA infection was also independently associated with secondary outcome measures. Although risks of non-MRSA infections were also associated with adverse outcomes in the multivariate analyses, MRSA posed higher risks, as reflected by higher odds ratio in all instances. The 22 patients with documented MRSA infection had significantly longer hospital stays than those with MSSA infection (median 24 days vs 8 days, p = 0.02). However, no significant differences were noted between the 2 groups in terms of secondary outcome. These results show that MRSA infection is a significant risk factor for adverse clinical outcomes among patients undergoing vascular surgery procedures. Infection with MRSA results in a greater risk of these outcomes when compared with non-MRSA infection. However, despite concerns regarding the virulence of this strain of staphylococcus, patients infected with MRSA had no higher rates of morbidity or mortality except for increased length of hospital stay when compared to patients with MSSA.

Assessment of handwashing practices with chemical and microbiologic methods: Preliminary results from a prospective crossover study

Background: Handwashing (HW) by clinical staff is the single most important measure for preventing transmission of nosocomial infection (NI). The primary objectives of this study were to improve the motivation and awareness of the importance of HW practices among health care workers (HCWs) and to assess the effectiveness of a new chemical system in checking HW compliance. In addition, we evaluated the efficacy and tolerability of 2 soap solutions used during regular working hours by HCWs at our institution. Method: A preliminary short training course was performed to promote HW compliance and awareness. We chose 2 surgical wards at our 1200-bed teaching hospital. Sampling of hands was conducted weekly during routine activities of HCWs without advance warning. We used the staff list as a sampling frame to select subjects. Data were collected anonymously. On the basis of a crossover study design, a plain soap and one containing 4% chlorhexidine gluconate (CHG) were used alternatively in each ward for 4 consecutive months. Hand samples were evaluated with microbiologic cultures and with a commercially available kit that measures adenosine triphosphate (ATP) bioluminescence. As additional process indicators, we examined the amount of hand soap and CHG solution distributed and rate of NIs. Results: A total of 74 HCWs were evaluated for hand contamination. During the 4-month study, we found a significant reduction in colony-forming unit counts (P <.008) and ATP levels (P <.002) compared with baseline values. The results showed a positive correlation (r = 0.68, P <.0001) between the microbial counts detected by standard culture and ATP levels measured with the commercial kit. Plain soap (P <.003) was more effective than CHG in reducing colony-forming unit counts among HCWs in the vascular surgery ward. We documented a reduction in the NI rate and an increase in the consumption of soap and paper towels. Conclusion: HW compliance improved during the study period among HCWs. The method to measure ATP bioluminescence is simple and easy to perform and provides reliable results within a few minutes of sampling hands. It can be used extensively to test HW compliance among HCWs. (Am J Infect Control 2002;30:334-40.)

Can simulation be used to reduce errors in health care delivery? The hospital drug distribution system.

To construct a simulation model of the hospital drug distribution system, to evaluate the effects of different changes to the system on unavailability-related medication administration errors (U-MAEs), to test the most promising system in a controlled trial and to explore the model's validity. A discrete-event simulation model of the drug distribution system was constructed, using data collected on a vascular surgery ward and a renal medicine ward as model inputs. The model's output was the U-MAE rate. The model was used to explore the effects on U-MAEs of different changes to the system. One of the changes predicted to reduce U-MAEs, a patients' own drugs scheme, was introduced on each study ward; U-MAE rates were measured using observations before and after its introduction and compared with those predicted by the model. The model predicted that the introduction of a patients' own drugs system would reduce unavailability-related errors on each ward; in practice, there was a slight decrease on the medical ward but an increase on the surgical ward. Reasons for these findings were explored and four contributing factors identified. Three of these related to failure to follow hospital procedures, the fourth to an issue for which no policy existed. If these factors had been taken into account, the error rates predicted by the model would have been similar to those observed. Simulation modelling is a potentially useful approach to the study of U-MAEs, although care must be taken to ensure that such models reflect actual practice rather than stated policy.

Molecular epidemiology of a multiple strain outbreak of methicillin-resistant Staphylococcus aureus amongst patients and staff

Since methicillin-resistant Staphylococcus aureus (MRSA) isolates are not endemic in our hospital, which is a tertiary referral centre, the finding of 13 MRSA isolates from 12 patients associated with an acute vascular surgery ward between October 1993 and December 1993 prompted further epidemiological and laboratory investigations. Two strains were distinguished by antibiogram and phage-typing. One strain, resembling EMRSA-16, colonized six patients and was probably introduced from another hospital in the Oxford Region. Five other patients were colonized by a second strain, gentamicm-resistant and non-typable by phage-typing, probably introduced into the hospital 12 months previously by a patient from Nairobi, Kenya. A 12th patient was colonized by both strains simultaneously. Of 46 staff members screened three were colonized—one by an EMRSA-16 strain, a second by the gentamicin-resistant ‘Nairobi’-strain and a third member carried yet a further distinct MRSA strain. The healthcare worker colonized by the ‘Nairobi’-strain had been carrying the isolate 12 months previously and was the likely source of this strain. These isolates were also characterized by the repetitive extragenic palindromic-polymerase chain reaction (REP-PCR), a novel PCR-based methodology which has not been previously used in characterizing Staphylococcus aureus in an outbreak. This method corroborated the strain classifications provided by the traditional methods, confirming that there had been spread of two strains simultaneously. Our study demonstrates that multiple strains of MRSA may circulate amongst patients and staff during an outbreak, patients may be colonized by more than one strain simultaneously and long-term staff carriage (>12 months) may be an important source of colonization in patients. REP-PCR is a rapid and effective molecular typing method for MRSA.