Duration of antimicrobial prophylaxis in vascular surgery

Antibiotics for preventing infection at the surgical site: Single dose vs. multiple doses

Background

Surgical site infections are common and expensive infections that can cause fatalities or poor patient outcomes. To prevent these infections, antibiotic prophylaxis is used. However, excessive antibiotic use is related to higher costs and the emergence of antimicrobial resistance.

Objectives

The present meta-analysis aimed to compare the effectiveness of a single dosage versus several doses of antibiotics in preventing the development of surgical site infections.

Methods

PubMed was used to find clinical trials evaluating the effectiveness of a single dosage versus several doses of antibiotics in avoiding the development of surgical site infections. The study included trials that were published between 1984 and 2022. Seventy-four clinical trials were included in the analysis. Odds ratios were used to compare groups with 95% confidence intervals. The data were displayed using OR to generate a forest plot. Review Manager (RevMan version 5.4) was used to do the meta-analysis.

Results

Regarding clean operations, there were 389 surgical site infections out of 5,634 patients in a single dose group (6.90%) and 349 surgical site infections out of 5,621 patients in multiple doses group (6.21%) (OR = 1.11, lower CI = 0.95, upper CI = 1.30). Regarding clean-contaminated operations, there were 137 surgical site infections out of 2,715 patients in a single dose group (5.05%) and 137 surgical site infections out of 2,355 patients in multiple doses group (5.82%) (OR = 0.87, lower CI = 0.68, upper CI = 1.11). Regarding contaminated operations, there were 302 surgical site infections out of 3,262 patients in a single dose group (9.26%) and 276 surgical site infections out of 3,212 patients in multiple doses group (8.59%) (OR = 1.11, lower CI = 0.84, upper CI = 1.47). In general, there were 828 surgical site infections out of 11,611 patients in a single dose group (7.13%) and 762 surgical site infections out of 11,188 patients in multiple doses group (6.81%) (OR = 1.05, lower CI = 0.93, upper CI = 1.20). The difference between groups was not significant.

Conclusion

The present study showed that using a single-dose antimicrobial prophylaxis was equally effective as using multiple doses of antibiotics in decreasing surgical site infections.

Enhanced recovery after surgery (ERAS) for vascular surgery: an evidence map and scoping review

BACKGROUND

Enhanced recovery after surgery (ERAS) interventions aim to improve patient outcomes. Vascular surgery patients have unique requirements and it is unclear which ERAS interventions are supported by an evidence base.

METHODS

We conducted a scoping review to identify ERAS randomized controlled trials (RCTs) published in the biomedical or nursing literature. We assessed interventions for applicability to vascular surgery and differentiated interventions given at preadmission, preoperative, intraoperative, and postoperative surgery stages. We documented the research in an evidence map.

RESULTS

We identified 76 relevant RCTs. Interventions were mostly administered in preoperative (23 RCTs; 30%) or intraoperative surgery stages (35 RCTs; 46%). The majority of studies reported mortality outcomes (44 RCTs; 58%), but hospital (27 RCTs; 35%) and intensive care unit (9 RCTs; 12%) length of stay outcomes were less consistently described.

CONCLUSION

The ERAS evidence base is growing but contains gaps. Research on preadmission interventions and more consistent reporting of key outcomes is needed.

Surgical amputation for patients with diabetic foot ulcers: A Chinese expert panel consensus treatment guide

BACKGROUND

Diabetic foot disease is a serious complication of diabetes mellitus. Patients with diabetes mellitus have a 25% lifetime risk for developing a foot ulcer, and between 14% and 24% of patients require a major or minor lower limb amputation due to severe gangrene. However, decisions concerning whether to amputate or whether to perform a major or minor lower limb amputation, and how best to determine the amputation plane remain unclear.

METHODS

To consolidate the current literature with expert opinion to make recommendations that will guide surgical amputation for patients with diabetic foot ulcers. A total of 23 experts experienced in surgical treatment of patients with diabetic foot ulcers formed an expert consensus panel, and presented the relevant evidence, discussed clinical experiences, and derived consensus statements on surgical amputation for patients with diabetic foot ulcers. Each statement was discussed and revised until a unanimous consensus was achieved.

RESULTS

A total of 16 recommendations for surgical amputation for patients with diabetic foot ulcers were formulated. The experts believe that determination of the amputation plane should be comprehensively evaluated according to a patient's general health status, the degree of injury, and the severity of lower limb vasculopathy. The Wagner grading system and the severity of diabetic lower extremity artery disease are important criteria when determining the degree of amputation. The severity of both diabetic foot infection and systemic underlying diseases are important factors when considering appropriate treatment. Moreover, consideration should also be given to a patient's socioeconomic status. Given the complexities of treating the diabetic foot, relevant issues in which consensus could not be reached will be discussed and revised in future.

CONCLUSION

This expert consensus could be used to guide doctors in clinical practice, and help patients with diabetic foot ulcers gain access to appropriate amputation treatment.

Effect of Antimicrobial Prophylaxis Duration on Health Care-Associated Infections After Clean Orthopedic Surgery: A Cluster Randomized Trial

IMPORTANCE

Postoperative health care-associated infections are associated with a greater deterioration in patients' general health status and social and economic burden, with at least 1 occurring in approximately 4% of acute care hospital patients. Antimicrobial prophylaxis prevents surgical site infections in various orthopedic procedures; however, its relationship with health care-associated infections remains unknown.

OBJECTIVE

To examine whether a shorter antimicrobial prophylaxis duration of less than 24 hours after surgery is not inferior to a longer duration in preventing health care-associated infections after clean orthopedic surgery.

DESIGN, SETTING, AND PARTICIPANTS

This open-label, multicenter, cluster randomized, noninferiority clinical trial was conducted in 5 tertiary referral hospitals in greater Tokyo metropolitan area, Japan, from May to December 2018. Adult patients undergoing clean orthopedic surgery were recruited until the planned number of participants was achieved (500 participants per group). Statistical analysis was conducted from July to December 2019.

INTERVENTIONS

Antimicrobial prophylaxis was discontinued within 24 hours after surgery in group 24 and 24 to 48 hours after surgery in group 48. Group allocation was switched every 2 or 4 months according to the facility-based cluster rule. Study-group assignments were masked from participants.

MAIN OUTCOMES AND MEASURES

The primary outcome was the incidence of health care-associated infections requiring antibiotic therapies within 30 days after surgery. The noninferiority margin was 4%.

RESULTS

Of the 1211 participants who underwent cluster allocation, 633 participants were in group 24 (median [IQR] age, 73 [61-80] years; 250 men [39.5%] and 383 women [60.5%]), 578 participants were in group 48 (median [IQR] age, 74 [62-81] years; 204 men [35.3%] and 374 women [64.7%]), and all were eligible for the intention-to-treat analyses. Health care-associated infections occurred in 29 patients (4.6%) in group 24 and 38 patients (6.6%) in group 48. Intention-to-treat analyses showed a risk difference of -1.99 percentage points (95% CI, -5.05 to 1.06 percentage points; P < .001 for noninferiority) between groups, indicating noninferiority. Results of adjusted intention-to-treat, per-protocol, and per designated procedure population analyses supported this result, without a risk of antibiotic resistance and prolonged hospitalization.

CONCLUSIONS AND RELEVANCE

This cluster randomized trial found noninferiority of a shorter antimicrobial prophylaxis duration in preventing health care-associated infections without an increase in antibiotic resistance risk. These findings lend support to the global movement against antimicrobial resistance and provide additional information on adequate antimicrobial prophylaxis for clean orthopedic surgery.

TRIAL REGISTRATION

Identifier: UMIN000030929.

How to Prevent Surgical Site Infection in Vascular Surgery: A Review of the Evidence

BACKGROUND

This review aims to identify and review the current evidence for preventing postoperative surgical site infections in abdominal aortic aneurysm surgery or infrainguinal arterial surgery.

METHODS

Extended literature review of clinical trials that examined the prevention of postoperative surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. Searches were conducted on Ovid MEDLINE (1950 - 13 March 2020) using key terms for vascular surgery, surgical site infections and specific preventative techniques. Articles were included if they discussed a relationship between a preventative technique and surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. The GRADE guidelines were used to assess the quality of evidence.

RESULTS

21 techniques and 81 studies were included. Prophylactic antibiotics and negative pressure wound therapy have a high quality of evidence for the prevention of surgical site infections in abdominal aortic aneurysm or infrainguinal arterial surgery. A moderate quality evidence base was identified for gentamicin containing collagen implant (confined to high surgical site infection risk centers). Currently, there is a low or very low quality of evidence to suggest a reduction in the surgical site infection rate for combination therapy, glycaemic control, Methicillin-resistant Staphylococcus aureus screening and absorbable suture. Evidence suggests no beneficial effect for nutritional supplementation, chlorhexidine bath, hair removal therapy, Staphylococcus aureus nasal eradication, cyanoacrylate microsealant, silver grafts, rifampicin bonded grafts, triclosan coated suture and postoperative wound drains. Endoscopic saphenous vein harvest may reduce surgical site infection rate (very low quality of evidence) but may lower long-term patency. Autologous vein grafts may increase surgical site infections (very low quality of evidence) but may provide better long-term patency rates in above-knee infrainguinal bypass surgery. There was no identified evidence for perioperative normothermia, electrosurgical bipolar vessel sealer or Dermabond and Tegaderm for surgical site infection prevention in vascular surgery.

CONCLUSIONS

Prophylactic antibiotics and postoperative negative pressure wound therapy are effective in the prevention of postoperative surgical site infection in abdominal aortic aneurysm or infrainguinal arterial surgery. There exists a significant risk of bias in the literature for many preventative techniques and further studies are required to investigate the efficacy of gentamicin containing collagen implant, and specific combination therapies.

Assessment of implementation of antibiotic stewardship program in surgical prophylaxis at a secondary care hospital in Ras Al Khaimah, United Arab Emirates

Antibiotic overuse is a major factor for causing antibiotic resistance globally. However, only few studies reported the implementation and evaluation of antimicrobial stewardship programs in Gulf Cooperation Council. This study was conducted within 8-months periods to evaluate the effect of the newly implemented antibiotic stewardship program on improving the prescribing practice of surgical antibiotic prophylaxis in a secondary care hospital in the United Arab Emirates by releasing local hospital guidelines. The data of 493 in patients were documented in the predesigned patient profile form and the prescribing practice of surgical antibiotic prophylaxis for clean and clean-contaminant surgical procedures was compared and analyzed two months’ prior (period A) and post (period B) the implementation of antibiotic stewardship program. The 347 patient’s data (PD) were analyzed during period A and 146 PD during period B. The prescription of piperacillin/tazobactam was decreased from 2.4% from all surgical prophylaxis antibiotic orders in period A to 0% in period B. The appropriateness of the antibiotic therapy was found to differ non significantly for the selection of prophylactic antibiotic (p = 0.552) and for the timing of first dose administration (p = 0.061) between A and B periods. The total compliance was decreased non significantly (P = 0.08) from 45.3 to 40.2%. Overall, the guidelines have improved the prescribing practice of antibiotics prior to surgery. However, further improvement can be achieved by initiating educational intervention via cyclic auditing strategy.

Groin dissections in skin cancer: Effect of a change in prophylactic antibiotic protocol

OBJECTIVES

To determine whether groin dissection surgical site infection (SSI) incidence changed with shorter post-operative antibiotic prophylaxis.

BACKGROUND

Post-operative prophylaxis changed due to antimicrobial stewardship, from regular oral antibiotics until drain removal, to three intravenous doses. Both groups had a single intravenous dose at induction.

METHODS

A prospective database of groin dissections for metastatic skin cancer was retrospectively reviewed for SSI according to Public Health England criteria. Eighty groin dissections in 79 consecutive patients were included: 40 had oral antibiotics until drain removal [mean 26±7 (range 19-36) days] and 39 had three post-operative intravenous doses.

RESULTS

Longer prophylaxis was associated with lower SSI incidence [10 (25%) versus 21 (54%), odds ratio (OR) 3.50, 95% confidence interval (CI) 1.34-9.08, p = 0.009], fewer deep infections [5 (13%) versus 16 (41%), OR 4.89, 95% CI 1.57-15.13, p = 0.004], fewer readmissions for infection [5 (13%) versus 15 (38%), OR 4.38, 95% CI 1.40-13.65, p = 0.008], but similar seroma incidence [18 (45%) versus 16 (41%), OR 0.85, 95% CI 0.35-2.07, p = 0.72] and wound dehiscence [7 (18%) versus 5 (13%), OR 0.69, 95% CI 0.20-2.40, p = 0.56]. BMI ≥30 (n = 21) was associated with SSI, occurring in 13 of 21 (62%) (OR 3.859, 95% CI 1.34-11.10, p = 0.01). Median infection onset was 22 days (IQR 12-27) versus 17 (IQR 13-22), (p = 0.53). Multiple organisms were cultured in 21 of 31 (68%) patients with positive microbiological samples.

CONCLUSIONS

SSI rates doubled with shorter prophylaxis; deep infections and readmissions for infection tripled. Obesity was independently associated with infection. Seroma and wound dehiscence incidence were unchanged. Infections mainly occurred in the third week after surgery and were polymicrobial.

Questionnaire Survey Regarding Prevention of Surgical Site Infection after Neurosurgery in Japan: Focus on Perioperative Management and Administration of Surgical Antibiotic Prophylaxis

Various guidelines regarding surgical site infection (SSI) have recently been established. However, perioperative management of the wound and use of antibiotics have never been standardized completely in departments of neurosurgery in Japan. This survey investigated current perioperative management and administration of surgical antibiotic prophylaxis (SAP) and compared with guidelines intended to reduce SSI associated with neurosurgery in Japan. Questionnaires were distributed to members of the conference on Neurosurgical Techniques and Tools and the Japan Society of Aesthetic Neurosurgery via internet. The questionnaires asked about methods of perioperative management. A total of 255 members returned answers to the questionnaires. The questionnaires revealed that partial or no removal of the hair and hair shampooing at the day before surgery were performed in 96.1% and 88.1% of each institute following the World Health Organization (WHO) guidelines. Use of SAP at just before, during, and after surgery were 65.0%, 86.2%, and 63.0%, respectively. The postoperative period of use of intravenous SAP prolonged beyond 24 h in 80.0% against the recommendation of WHO. Perioperative management of wounds and use of SAP varies in institutes in Japan and some procedures were far different from the WHO guidelines. Japanese neurosurgeons should notice the prolonged SAP and comply with the WHO guidelines.

New WHO recommendations on intraoperative and postoperative measures for surgical site infection prevention: an evidence-based global perspective

Surgical site infections (SSIs) are the most common health-care-associated infections in developing countries, but they also represent a substantial epidemiological burden in high-income countries. The prevention of these infections is complex and requires the integration of a range of preventive measures before, during, and after surgery. No international guidelines are available and inconsistencies in the interpretation of evidence and recommendations in national guidelines have been identified. Considering the prevention of SSIs as a priority for patient safety, WHO has developed evidence-based and expert consensus-based recommendations on the basis of an extensive list of preventive measures. We present in this Review 16 recommendations specific to the intraoperative and postoperative periods. The WHO recommendations were developed with a global perspective and they take into account the balance between benefits and harms, the evidence quality level, cost and resource use implications, and patient values and preferences.

Five day antibiotic prophylaxis for major lower limb amputation reduces wound infection rates and the length of in-hospital stay

OBJECTIVE

To compare wound infection, revision rates and hospital stay after major lower limb amputation between patients receiving 24 hours versus 5 days of prophylactic antibiotics.

METHODS

The outcomes of a consecutive series of 40 major lower limb amputations in patients receiving a short 24-hour course of combined prophylactic antibiotics (flucloxacillin/vancomycin + gentamicin/ciproxin + metronidazole) were retrospectively analysed. Following this a further consecutive group of 40 major lower limb amputations were studied prospectively following the institution of a 5-day combined regime using the same antibiotics.

RESULTS

The 2 groups of patients were similar in terms of demographics, vascular risk factors and level of amputation. The 5-day antibiotic regime led to a significant reduction in wound infection rates (5% vs. 22.5%, P=0.023) and a reduced length of hospital stay (22 vs. 34 days, P=0.001). Revision rates were lower (2.5% vs. 10%) but did not reach statistical significance (P=0.36). More patients in the prospective 5-day antibiotic series were operated on by the vascular trainee. (77.5% vs. 55% P=0.033).

CONCLUSIONS

This data supports the use of a prolonged 5-day course of combined antibiotics after major lower limb amputation. This appears to reduce stump infection rates leading to shorter in-hospital stay.

Prevention of infection in peripheral arterial reconstruction: A systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to determine the effectiveness of perioperative strategies to prevent infection in patients undergoing peripheral arterial reconstruction.

METHODS

All randomized controlled trials (RCTs) evaluating measures intended to reduce or prevent infection in arterial surgery were identified through searches of the Cochrane Peripheral Vascular Diseases Group specialized trials register, the Cochrane Central Register of Controlled Trials (CENTRAL), and reference lists of relevant articles. Two authors independently selected and assessed the quality of included trials. Relative risk (RR) was used as a measure of effect for each dichotomous outcome.

RESULTS

The study included 34 RCTs. Of these, 22 were trials of prophylactic systemic antibiotics, 3 of rifampicin-bonded grafts, 3 of preoperative skin antisepsis, 2 of suction wound drainage, 2 of minimally invasive in situ bypass techniques, and individual trials of intraoperative glove change and wound closure techniques. Wound infection or early graft infection outcomes were recorded in all trials. Only two trials, both of rifampicin bonding, followed up graft infection outcomes to 2 years. Prophylactic systemic antibiotics reduced the risk of wound infection (RR, 0.25; 95% confidence interval [CI], 0.17 to 0.38) and early graft infection in a fixed-effect model (RR, 0.31; 95% CI, 0.11 to 0.85, P = .02). Antibiotic prophylaxis for >24 hours appeared to be of no added benefit (RR, 1.28; 95% CI, 0.82 to 1.98). There was no evidence that prophylactic rifampicin bonding to Dacron grafts reduced graft infection at 1 month (RR, 0.63; 95% CI, 0.27 to 1.49), or 2 years (RR, 1.05; 95% CI, 0.46 to 2.40). There was no evidence of a beneficial or detrimental effect on rates of wound infection with suction groin wound drainage (RR, 0.96; 95% CI, 0.50 to 1.86) or from preoperative bathing with antiseptic agents compared with unmedicated bathing (RR, 0.97; 95% CI, 0.70 to 1.36).

CONCLUSIONS

There is clear evidence of the benefit of prophylactic broad-spectrum antibiotics for vascular reconstruction. Many other interventions intended to reduce the risk of infection in arterial reconstruction lack evidence of effectiveness.

Prevention of infection in arterial reconstruction

BACKGROUND

Arterial reconstructions with prosthetic graft materials or vein are susceptible to infection with a resultant high patient mortality and risk of limb loss. To reduce the risk of infection effective perioperative measures are essential.

OBJECTIVES

To determine the effectiveness of perioperative strategies to prevent infection in patients undergoing peripheral arterial reconstruction.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group trials register (last searched May 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched Issue 2, 2006), and reference lists of relevant articles.

SELECTION CRITERIA

All randomised controlled trials (RCTs) evaluating measures intended to reduce or prevent infection in arterial surgery.

DATA COLLECTION AND ANALYSIS

AS and PSE independently selected and assessed the quality of included trials. Relative risk was used as a measure of effect for each dichotomous outcome.

MAIN RESULTS

Thirty-five RCTs were included. Of these, 23 were trials of prophylactic systemic antibiotics, three of rifampicin-bonded grafts, three of preoperative skin antisepsis, two of suction wound drainage, two of minimally invasive in situ bypass techniques, and individual trials of intraoperative glove change and wound closure techniques. Wound infection or early graft infection outcomes were recorded in all trials. Only two trials, both of rifampicin bonding, followed up graft infection outcomes to two years. Trials of antibiotics versus placebo were of highest quality with six double-blind studies of the ten included. Prophylactic systemic antibiotics reduced the risk of wound infection (Relative Risk (RR) 0.25, 95% Confidence Interval (CI) 0.17 to 0.38) and early graft infection in a fixed-effect model (RR 0.31, 95% CI 0.11 to 0.85, P = 0.02). Antibiotic prophylaxis for greater than 24 hours appears to be of no added benefit (RR 1.28, 95% CI 0.82 to 1.98). There was no evidence that prophylactic rifampicin bonding to dacron grafts reduced graft infection at either one month (RR 0.63, 95% CI 0.27 to 1.49) or two years (RR 1.05, 95% CI 0.46 to 2.40). There was no evidence of a beneficial or detrimental effect on rates of wound infection with suction groin-wound drainage (RR 0.96 95% CI 0.50 to 1.86) or of any benefit from a preoperative bathing or shower regimen with antiseptic agents over unmedicated bathing (RR 0.97, 95% CI 0.70 to 1.36).

AUTHORS' CONCLUSIONS

There is clear evidence of the benefits of prophylactic broad spectrum antibiotics. Many other interventions intended to reduce the risk of infection in arterial reconstruction lack evidence of effectiveness.

Pharmacokinetic–pharmacodynamic aspects of antimicrobial prophylaxis with teicoplanin in patients undergoing major vascular surgery

A prospective, two-arm, open study assessing plasma exposure to teicoplanin with two different prophylactic regimens (Group A (n = 23), 800 mg pre-operatively versus Group B (n = 24), 400 mg pre-operatively plus two doses of 200 mg 24 h apart) was carried out in patients undergoing major vascular surgery. The intent was to define the feasibility and the possible advantages of the single pre-operative high dose in ensuring therapeutically effective plasma concentrations (>10 mg/L) of teicoplanin even during long-lasting operations. At the end of the intervention, mean teicoplanin concentrations (+/-S.D.) were 14.05 +/- 5.13 mg/L and 5.39 +/- 2.13 mg/L in Groups A and B, respectively. At 24 h, average teicoplanin levels were 5.10 +/- 1.25 mg/L and 2.08 +/- 0.73 mg/L in Groups A and B, respectively; at 48 h they declined to 2.86 +/- 0.70 mg/L in Group A, whereas they rose to 2.67 +/- 0.82 mg/L after administration of 2.63 +/- 0.51 mg/kg at 24 h in Group B. Single pre-operative high-dose teicoplanin may ensure effective plasma levels even in cases of very long-lasting operations (>8 h) with no need for intraoperative re-dosing and may enable more appropriate prophylactic exposure than that achievable with the same total dose given in three administrations 24 h apart.

An evaluation of antimicrobial prophylaxis in paediatric surgery and its financial implication

OBJECTIVE

To assess the appropriateness of use of antimicrobial prophylaxis in paediatric surgery in Singapore.

METHODS

A prospective evaluation of the use of antimicrobial prophylaxis in paediatric patients undergoing surgery in KK Hospital, Singapore was carried out from September and December 2001. Process measures for the study included adherence to local or international guidelines, choice and dose of antimicrobial agent and timing and duration of prophylaxis. Outcome measures included surgical site and other related infections. A cost analysis was also performed to look at the extra expenditure due to any excessive use of antimicrobials.

RESULTS

A total of 171 patients with a mean age of 5.7 years (SD=4.5) were included in the study. Among the 117 (68.4%) elective and 54 (31.6%) emergency procedures, 22 cases (12.8%) were fully compliant with the guidelines. The most frequently encountered non-compliance types were unnecessary prolongation of prophylaxis (54.4%), inappropriate choice of antibiotics (42.7%) and overdose of antibiotics (26.3%). The estimated extra cost to patients for the study period was Sing$13,879.41 (US 8164.36).

CONCLUSION

The results showed a significantly high level of inappropriate use of antimicrobial prophylaxis in paediatric surgery in Singapore. However, when the individual factors such as appropriate choice of antibiotics, appropriate timing and duration were considered, the situation was very similar to the results obtained from overseas studies.

The measurement of wound infection after breast surgery

Infection in breast wounds often occurs in the form of cellulitis, but the conventional criteria for wound infection are the presence of either pus or a serous discharge containing pathogens. Wound scoring systems may offer a more quantitative and clinically relevant approach when evaluating the morbidity caused by infection in wounds. The aim of this study was to develop a wound scoring system for patients undergoing breast surgery. The components of previously described wound scoring systems were measured in 218 women undergoing nonreconstructive breast surgery. Using conventional criteria, the incidence of wound infection was 5.5% (12/218). However, 22% of the patients exhibited at least one sign of wound infection, and 11% of the patients received antibiotics for cellulitis without any other indication of a wound infection. The validity of the wound scoring system was supported by its strong content validity, the presence of construct validity as evidenced by concordance with the conventional criteria (p < 0.001), and criterion validity in the form of an association between the presence of a seroma and a positive wound score (p < 0.001). It was also noted that 27% of the patients with an appreciable wound score (more than 40 points) had cellulitis but did not satisfy the conventional criteria for a wound infection. In conclusion, it is advisable to use a wound scoring system that includes cellulitis when evaluating patients who have undergone breast surgery.

Bacterial colonisation of Doppler probes on vascular surgical wards

AIM

hospital acquired infections cost the NHS 1 pound sterling billion each year and medical equipment may act both as source and vector of nosocomial infection. This study examined bacterial contamination of Doppler ultrasound probes (USP) in routine use on vascular surgical wards in six hospitals and the knowledge of staff about the potential for cross infection from contaminated probes.

METHODS

probe head impressions and swab cultures of probe holders were plated on mannitol salt agar before and after cleaning with a paper towel. Putative S. aureus isolates were identified to species level and susceptibility to selected antimicrobials tested. Concurrently, junior medical staff were surveyed about probe cleaning protocols.

RESULTS

methicillin susceptible S. aureus was isolated from 2/21 (10%) with near confluent bacterial growth from six others (28%). The latter may have obscured low numbers of S. aureus. Further since swabs were plated without prior enrichment culture, it is likely that contamination with S. aureus might have been underestimated. No positive cultures were obtained after wiping the USP with a paper towel. 22/23 (95%) junior doctors failed to clean the USP prior to use.

CONCLUSION

USP contamination with pathogenic bacteria occurs under "in-use" conditions and junior medical staff are unaware of simple measures to prevent this. Strict guidelines for USP cleaning between patient use should, therefore, be adopted particularly when monitoring postoperative graft patency.

Antibiotic prophylaxis in clean surgery: vascular surgery

The commonest and most dangerous infective complication in vascular surgery is prosthetic graft infection. Despite the use of routine systemic antibiotic prophylaxis, graft infection occurs after 3-5% of all prosthetic vascular reconstructions. Infection is associated with a high rate of major morbidity and mortality, with significant time and cost implications. Management can be difficult and the outcome is often disappointing. Data from Italian Registry of Prosthetic Graft Infections show that the commonest site of infection is the aorto-femoral district and that involved bacteria are usually gram-positive in early and low-grade infections and gram-negative in late and high-grade infections. Results are poor, with a mortality rate of 15% for elective surgery and of 60% for emergency interventions. We report the results of a multicenter randomized controlled trial of rifampicin-bonded Dacron grafts in aorto-femoral surgery, in which our Department was involved. Data demonstrate a reduction in total early wound and graft infection rates, and 2-year results show a small, non-significant reduction in graft infection (1.7% in study group, 2.3% in control group). The same results were obtained in two other multicenter trials.

Antibiotic prophylaxis for patients undergoing breast surgery

Some groups of patients undergoing clean surgery benefit from the provision of antibiotic prophylaxis against wound infection. Breast surgery may belong to this category because several substantial studies have reported that it is accompanied by an unacceptably high rate of wound infection. However, only two clinical trials have addressed this issue and both produced equivocal results. Resolution of this problem is important because, aside from the usual advantages obtained by preventing such complications, wound infection diminishes the proportion of patients with breast cancer who start adjuvant regimens within an optimum time after surgery.

Distribution and serum concentration of sisomicin released from fibrin glue-sealed dacron graft in the rat and human

We investigated whether or not fibrin glue (FG) used as a sealant in vascular prostheses to prevent leakage might be useful as a carrier of antibiotics for the prevention of local graft infection. Sisomicin (SISO) was incorporated into fibrin glue (SISO-FG) and evaluated as to its safety and pharmacokinetics. SISO (1.75 mg) -FG Dacron grafts were implanted subcutaneously in the anterior abdominal region of Sprague-Dawley rats, and then the changes in SISO concentrations in the serum and in the tissue around the implantation sites were compared with those same sites in rats that had had intravenous injection of SISO (1.75 mg). The serum SISO concentrations were significantly lower in the SISO-FG Dacron graft group than they were in the intravenous injection group. However, until 4 h after implantation the SISO concentrations in the tissues around the implantation sites were significantly higher in the SISO-FG Dacron group than they were in the iv injection group, and the peak concentrations during that time were 5.8 times higher for the SISO-FG Dacron group than they were for the intravenous injection group. The ratio of the area under the tissue concentration time curve of SISO (AUC tissue) after implantation of the SISO-FG Dacron graft to that after intravenous injection of SISO was 13.08. Therefore, FG was considered to control the release of SISO into the serum and to maintain a high SISO concentration in the tissue around the implantation site. Clinically, SISO (45 mg) -FG was applied directly to the Dacron grafts implanted in 10 patients who underwent prosthetic vascular reconstruction. No graft infection was observed in any of the patients who received SISO-FG Dacron grafts. The mean serum concentration of SISO was 0.65+/-0.17 microg/mL after 1 h and 0.33+/- 0.21 microg/mL after 3 h. The results of these clinical applications are in close correlation with those of the animal experiment and suggest that FG is useful as a carrier of SISO, allowing its controlled release for the prevention of local infection.