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.

Cemented hemiarthroplasty or hip replacement for intracapsular neck of femur fracture? A comparison of 7732 matched patients using national data.

BACKGROUND: The treatment of choice for intracapsular neck of femur (NOF) fractures in younger, more active patients remains unknown. Some surgeons advocate total hip replacement (THR). AIM: This study aimed to compare complications following THR and hemiarthroplasty using the Hospital Episode Statistics (HES) database in England. METHOD: Dislocation and revision rates were extracted for all patients with NOF fracture who underwent either cemented hemiarthroplasty or cemented THR between January 2005 and December 2008. To make a 'like for like' comparison all 3866 THR patients were matched to 3866 hemiarthroplasty patients (from a total of 41,343) in terms of age, sex and Charlson score. RESULTS AND CONCLUSION: Eighteen-month dislocation was significantly higher in the THR group (2.4% vs. 0.5%, odds ratio (OR) 3.90 (2.99-5.05), p<0.001). This difference was sustained at the 4-year stage (2.9% vs. 0.9%, OR 3.18 (1.58-6.94), p=0.001) in a subset of patients with longer follow-up. There was no significant difference in revision rate up to 4 years (1.8% vs. 2.1%, OR 0.85 (0.46-1.55), p=0.666). In this national analysis of matched patients short- and medium-term dislocation rates following THR were significantly higher than following cemented hemiarthroplasty, without any difference in revision rates at 4 years. The low risk of dislocation may be acceptable in order to experience the apparent functional benefits of THR.

Cemented versus cementless hemiarthroplasty for intracapsular neck of femur fracture--a comparison of 60,848 matched patients using national data.

National guidelines recommend cemented hemiarthroplasty for intracapsular fractured neck of femur (NOF), based on evidence of less pain, better mobility and lower costs. We aimed to compare complications following cemented and cementless implants, using the national hospital episode statistics (HES) database in England. Dislocation, revision, return to theatre and medical complications were extracted for all patients with NOF fracture who underwent hemiarthroplasty between January 2005 and December 2008. To make a 'like for like' comparison all 30,424 patients with a cementless implant were matched to 30,424 cemented implants (from a total of 42,838) in terms of age, sex and Charlson co-morbidity score. In the cementless group, 18-month revision (1.62% versus 0.57% (OR 2.90, p<0.001)), 4-year revision (2.45% versus 1.11% (OR 2.28, p<0.001)) and 30-day chest infection (8.14% versus 7.23% (OR 1.14, p=0.028)) were significantly higher. Four-year dislocation rate was higher in cemented implants (0.60% versus 0.26% (OR 0.45, p<0.001)). No significant differences were seen in return to theatre or other medical complications. In this national analysis of matched patients mid-term revision and perioperative chest infection was significantly higher in the cementless group. This supports the published evidence and national guidelines recommending cement fixation of hemiarthroplasty.

Efficacy of a novel air filtration pillow for avoidance of perennial allergens in symptomatic adults.

BACKGROUND: Nighttime allergen exposures are a primary contributor to the development of allergic and asthmatic morbidities. Disease management guidelines recommend the use of environmental control measures to reduce these exposures, but clinically relevant reductions are difficult to achieve because most measures control only 1 allergen source among many in the bedroom environment. OBJECTIVE: To determine whether a novel localized approach to nighttime allergen avoidance provides effective exposure reductions and clinical benefits. METHODS: Thirty-five adults with perennial allergic rhinoconjunctivitis (dog, cat, or dust mite sensitivity) were randomized to receive PureZone, a combination therapy involving localized air filtration and pillow encasement, or placebo in a crossover trial with two 2-week treatment periods separated by a 1-week washout. Nasal and ocular allergy symptoms, quality of life, and breathing zone particulate exposure were assessed. Bedroom allergen dust samples were collected in the sleeping environment. RESULTS: Reductions (>99.99%) in allergen-sized particulate (> or = 0.3 microm) in the breathing zone led to significant improvements in nocturnal nasal and ocular allergy symptoms (P < .001) and quality of life (P = .02) for the active vs placebo device. Significant nocturnal symptom reductions vs placebo occurred the second night of use and were maintained for the duration of treatment; these reductions improved sleep problems in particular (P = .02). Allergens were detected in 100% of bedrooms, of which 44% had levels that exceeded sensitizing thresholds. CONCLUSIONS: The combination therapy of pillow encasement and localized air filtration provided effective nighttime allergen exposure reductions and clinical benefits without the use of adjunctive therapy.