Effect of unidirectional airflow ventilation on surgical site infection in cardiac surgery: environmental impact as a factor in the choice for turbulent mixed air flow.

BACKGROUND: Surgical site infection (SSI) in the form of postoperative deep sternal wound infection (DSWI) after cardiac surgery is a rare, but potentially fatal, complication. In addressing this, the focus is on preventive measures, as most risk factors for SSI are not controllable. Therefore, operating rooms are equipped with heating, ventilation and air conditioning (HVAC) systems to prevent airborne contamination of the wound, either through turbulent mixed air flow (TMA) or unidirectional air flow (UDAF). AIM: To investigate if the risk for SSI after cardiac surgery was decreased after changing from TMA to UDAF. METHODS: This observational retrospective single-centre cohort study collected data from 1288 patients who underwent open heart surgery over 2 years. During the two study periods, institutional SSI preventive measures remained the same, with the exception of the type of HVAC system that was used. FINDINGS: Using multi-variable logistic regression analysis that considered confounding factors (diabetes, obesity, duration of surgery, and re-operation), the hypothesis that TMA is an independent risk factor for SSI was rejected (odds ratio 0.9, 95% confidence interval 0.4-1.8; P>0.05). It was not possible to demonstrate the preventive effect of UDAF on the incidence of SSI in patients undergoing open heart surgery when compared with TMA. CONCLUSION: Based on these results, the use of UDAF in open heart surgery should be weighed against its low cost-effectiveness and negative environmental impact due to high electricity consumption. Reducing energy overuse by utilizing TMA for cardiac surgery can diminish the carbon footprint of operating rooms, and their contribution to climate-related health hazards.

Ventilation design conditions associated with airborne bacteria levels within the wound area during surgical procedures: a systematic review.

BACKGROUND: Without confirmation of the ventilation design conditions (typology and airflow rate), the common practice of identifying unidirectional airflow (UDAF) systems as equivalent to ultra-clean air ventilation systems may be misleading, but also any claims about the ineffectiveness of UDAF systems should be doubted. The aim of this review was to assess and compare ventilation system design conditions for which ultra-clean air (mean <10 cfu/m3) within 50 cm from the wound has been reported. Six medical databases were systematically searched to identify and select studies reporting intraoperative airborne levels expressed as cfu/m3 close to the wound site, and ventilation system design conditions. Available data on confounding factors such as the number of persons present in the operating room, number of door openings, and clothing material were also included. Predictors for achieving mean airborne bacteria levels within <10 cfu/m3 were identified using a penalized multivariate logistic regression model. Twelve studies met the eligibility criteria and were included for analysis. UDAF systems considered had significantly higher air volume flows compared with turbulent ventilation (TV) systems considered. Ultra-clean environments were reported in all UDAF-ventilated (N = 7) rooms compared with four of 11 operating rooms equipped with TV. On multivariate analysis, the total number of air exchange rates (P=0.019; odds ratio (OR) 95% confidence interval (CI): 0.66-0.96) and type of clothing material (P=0.031; OR 95% CI: 0.01-0.71) were significantly associated with achieving mean levels of airborne bacteria <10 cfu/m3. High-volume UDAF systems complying with DIN 1946-4:2008 standards for the airflow rate and ceiling diffuser size unconditionally achieve ultra-clean air close to the wound site. In conclusion, the studied articles demonstrate that high-volume UDAF systems perform as ultra-clean air systems and are superior to TV systems in reducing airborne bacteria levels close to the wound site.

Modified shoelace technique for delayed primary closure of the thigh after acute compartment syndrome.

The authors report a case of acute compartment syndrome in the thigh in a 19-year-old man with multiple injuries including fracture of the femoral diaphysis. Decompressive fasciotomy was performed emergently. Complete progressive closure of the wound without split-thickness skin grafting was achieved using a modified shoelace technique: sutures were run inside wide drains placed in contact with the muscles and were then tightened over the skin. These drains enlarged the contact area between sutures and muscles, preventing damage to muscles.

[Filling of bone defects with tricalcium phosphate beta in traumatology]. / Comblement des pertes de substance osseuse par le phosphate tricalcique beta en traumatologie.

AIM OF STUDY: Synthetic bone substitutes like calcium phosphate ceramics have been used in orthopaedic surgery for several years. The aim of this study was to assess the results of the use of tricalcium phosphate beta for filling bone defects in trauma cases. PATIENTS AND METHOD: beta tricalcium phosphate was used in 24 trauma cases. The GESTO classification (Association pour l'étude des Greffes et Substituts Tissulaires en Orthopédie) and a qualitative scale were used to estimate the integration. RESULTS: With a mean follow-up of 20 months, integration was excellent in 41.2%, good in 29.2% and moderate in 17.4%. No fibrous encapsulation was observed around the implants in any case. Sepsis occurred in 3 cases with open fractures. CONCLUSION: beta-Tricalcium phosphate seems in our experience to be an excellent bone substitute for filling bone defects in trauma cases.