Forced-air warming design: evaluation of intake filtration, internal microbial buildup, and airborne-contamination emissions.

Forced-air warming devices are effective for the prevention of surgical hypothermia. However, these devices intake nonsterile floor-level air, and it is unknown whether they have adequate filtration measures to prevent the internal buildup or emission of microbial contaminants. We rated the intake filtration efficiency of a popular current-generation forced-air warming device (Bair Hugger model 750, Arizant Healthcare) using a monodisperse sodium chloride aerosol in the laboratory. We further sampled 23 forced-air warming devices (same model) in daily hospital use for internal microbial buildup and airborne-contamination emissions via swabbing and particle counting. Laboratory testing found the intake filter to be 63.8% efficient. Swabbing detected microorganisms within 100% of the forced-air warming blowers sampled, with isolates of coagulase-negative staphylococci, mold, and micrococci identified. Particle counting showed 96% of forced-air warming blowers to be emitting significant levels of internally generated airborne contaminants out of the hose end. These findings highlight the need for upgraded intake filtration, preferably high-efficiency particulate air filtration (99.97% efficient), on current-generation forced-air warming devices to reduce contamination buildup and emission risks.

Patient warming excess heat: the effects on orthopedic operating room ventilation performance.

BACKGROUND: Patient warming has become a standard of care for the prevention of unintentional hypothermia based on benefits established in general surgery. However, these benefits may not fully translate to contamination-sensitive surgery (i.e., implants), because patient warming devices release excess heat that may disrupt the intended ceiling-to-floor ventilation airflows and expose the surgical site to added contamination. Therefore, we studied the effects of 2 popular patient warming technologies, forced air and conductive fabric, versus control conditions on ventilation performance in an orthopedic operating room with a mannequin draped for total knee replacement. METHODS: Ventilation performance was assessed by releasing neutrally buoyant detergent bubbles ("bubbles") into the nonsterile region under the head-side of the anesthesia drape. We then tracked whether the excess heat from upper body patient warming mobilized the "bubbles" into the surgical site. Formally, a randomized replicated design assessed the effect of device (forced air, conductive fabric, control) and anesthesia drape height (low-drape, high-drape) on the number of bubbles photographed over the surgical site. RESULTS: The direct mass-flow exhaust from forced air warming generated hot air convection currents that mobilized bubbles over the anesthesia drape and into the surgical site, resulting in a significant increase in bubble counts for the factor of patient warming device (P < 0.001). Forced air had an average count of 132.5 versus 0.48 for conductive fabric (P = 0.003) and 0.01 for control conditions (P = 0.008) across both drape heights. Differences in average bubble counts across both drape heights were insignificant between conductive fabric and control conditions (P = 0.87). The factor of drape height had no significant effect (P = 0.94) on bubble counts. CONCLUSIONS: Excess heat from forced air warming resulted in the disruption of ventilation airflows over the surgical site, whereas conductive patient warming devices had no noticeable effect on ventilation airflows. These findings warrant future research into the effects of forced air warming excess heat on clinical outcomes during contamination-sensitive surgery.

Development of electronic software for the management of trauma patients on the orthopaedic unit.

INTRODUCTION: Continuity of patient care is an essential prerequisite for the successful running of a trauma surgery service. This is becoming increasingly difficult because of the new working arrangements of junior doctors. Handover is now central to ensure continuity of care following shift change over. The purpose of this study was to compare the quality of information handed over using the traditional ad hoc method of a handover sheet versus a web-based electronic software programme. It was hoped that through improved quality of handover the new system would have a positive impact on clinical care, risk and time management. METHODS: Data was prospectively collected and analyzed using the SPSS 14 statistical package. The handover data of 350 patients using a paper-based system was compared to the data of 357 cases using the web-based system. Key data included basic demographic data, responsible surgeon, location of patient, injury site including site, whether fractures were open or closed, concomitant injuries and the treatment plan. A survey was conducted amongst health care providers to assess the impact of the new software. RESULTS: With the introduction of the electronic handover system, patients with missing demographic data reduced from 35.1% to 0.8% (p<0.0001) and missing patient location from 18.6% to 3.6% (p<0.0001). Missing consultant information and missing diagnosis dropped from 12.9% to 2.0% (p<0.0001) and from 11.7% to 0.8% (p<0.0001), respectively. The missing information regarding side and anatomical site of the injury was reduced from 31.4% to 0.8% (p<0.0001) and from 13.7% to 1.1% (p<0.0001), respectively. In 96.6% of paper ad hoc handovers it was not stated whether the injury was 'closed' or 'open', whereas in the electronic group this information was evident in all 357 patients (p<0.0001). A treatment plan was included only in 52.3% of paper handovers compared to 94.7% (p<0.0001) of electronic handovers. A survey revealed 96% of members of the trauma team felt an improvement of handover since the introduction of the software, and 94% of members were satisfied with the software. CONCLUSIONS: The findings of our study show that the use of web-based electronic software is effective in facilitating and improving the quality of information passed during handover. Structured software also aids in improving work flow amongst the trauma team. We argue that an improvement in the quality of handover is an improvement in clinical practice.

Anticardiolipin antibodies as a risk factor for venous thromboembolism in a population-based prospective study.

Anticardiolipin antibodies, one of the family of 'antiphospholipid' antibodies, increase the risk of venous thromboembolism in the presence of autoimmune disease. Our objective was to determine prospectively whether there is a positive association between anticardiolipin antibodies and venous thromboembolism in ostensibly healthy adults. We conducted a nested case-control study (n = 317 patients and n = 655 control subjects) in a longitudinal study of over 20 000 participants. Baseline (prediagnosis) anticardiolipin IgG and IgM antibodies were assessed by enzyme-linked immunoassays. Venous thromboembolism was validated using standardized criteria for venous thrombosis and pulmonary embolism. There was no association between anticardiolipin antibodies and subsequent venous thromboembolism occurrence, overall or in any subgroup. For example, the multivariate-adjusted relative risk was 0.88 (95% confidence interval, 0.43, 1.78) for greater than versus less than the 95th percentile of anticardiolipin IgG. In conclusion, in this general population sample, an elevated anticardiolipin antibody level was not a risk factor for venous thromboembolism.