Functional assessment of military aircrew applicants in a hypobaric chamber.

BACKGROUND: Aircrew are exposed to environmental pressure changes. In the Republic of Singapore Air Force (RSAF), applicants assessed to be at intermediate risk of otic barotrauma undergo a hypobaric chamber assessment ["trial of chamber" (TOC)] to functionally evaluate their suitability for military aircrew vocations. AIMS: To identify factors associated with TOC failure among applicants with otorhinolaryngological conditions. METHODS: All applicants to RSAF aircrew vocations who were assessed to be at intermediate risk of otic barotrauma over a 3-yr period were identified using the RSAF Aeromedical Centre's electronic database. Their medical records, as well as the TOC assessment records of the subset of applicants who underwent TOC, were reviewed for demographic data, clinical findings, and TOC outcomes. RESULTS: Of the 483 identified applicants, 374 (77%) had abnormal otoscopic findings, 103 (21%) had rhinitis symptoms, and 6 (1%) had previous ENT surgery. 123 (25%) underwent TOC, of which 20 (16%) failed. Holding other predictor variables constant, the odds of TOC failure increased by 0.79 per unit decrease in BMI (95% CI 0.63-0.99), and the odds of TOC failure increased by 0.93 per kg decrease in body weight (95% CI 0.87-1.00). An abnormal tympanogram was not a statistically significant predictor of TOC failure (OR 1.96, 95% CI 0.59-6.42). Of the 47 applicants who passed TOC and were eventually recruited, none subsequently developed otic barotrauma (mean follow-up, 3.3 yr ± 1.5 yr). CONCLUSIONS: Applicants with lower weight and BMI are more likely to develop otic barotrauma with environmental pressure change. Tympanometry cannot be reliably used to identify applicants who would more likely pass TOC.

Managing common mental health disorders in healthcare workers.

BACKGROUND: Approximately a quarter of sickness absence in the UK National Health Service (NHS) is attributed to common mental health disorders (CMHDs). This is costly to the NHS and impacts on patient care and staff morale. Little is known about the occupational health (OH) management of NHS staff who take sick leave for CMHDs. AIMS: To explore the current OH management of NHS staff on sick leave for CMHDs. METHODS: We invited providers of NHS OH services identified from the NHS Health at Work Network and Commercial OH Providers Association to complete a survey on the management of employees off work because of CMHDs. Analysis involved descriptive statistics and content analysis. RESULTS: Forty-nine (39%) of the 126 OH departments approached responded. The majority (98%) had an organizational sickness absence policy that included triggers for referral for staff absent with CMHDs. In 63%, referral occurred 8-28 days after the onset of absence; in 92%, the consultation was completed by an OH nurse or OH physician. Content of the first consultation often included assessment of symptoms and medication for CMHDs. Case management and regular reviews were least commonly used despite evidence on their effectiveness in supporting return to work. All providers offered some support for managers of staff with CMHDs. CONCLUSION: Variation existed between providers of NHS OH services in the timing of referrals, use of case management and regular reviews for staff with CMHDs. Our findings suggest that current evidence-based guidance on interventions to improve return to work is not being implemented consistently.

Mechanical testing of spider silk at cryogenic temperatures.

A method and results for mechanical testing of spider silk in extreme environments is presented. In particular, silk from the spider Steatoda triangulosa is harvested, and samples are subjected to cryogenic temperatures by means of liquid nitrogen submersion. Samples are destructively tested while immersed in liquid nitrogen, and the stress-strain characteristics are compared to those of silk at room temperature. The strength, elasticity, and toughness of the cryogenically submersed silk are determined. It is found that on average, silk is 64% stronger while immersed in liquid nitrogen (i.e., at -196°C). The testing method could also be used for testing of silk in chemically hostile environments.