The association of hand and wrist injuries with other injuries in multiple trauma patients. A retrospective study in a UK Major Trauma Centre.

BACKGROUND: Approximately 20,000 major trauma cases occur in England every year. However, the association with concomitant upper limb injuries is unknown. This study aims to determine the incidence, injury pattern and association of hand and wrist injuries with other body injuries and the Injury Severity Score (ISS) in multiply injured trauma patients. METHODS: Single centre retrospective study was performed at a level-one UK Major Trauma Centre (MTC). Trauma Audit and Research Network (TARN) eligible multiply injured trauma patients that were admitted to the hospital between January 2014 and December 2018 were analysed. TARN is the national trauma registry. Eligible patients were: a trauma patient of any age who was admitted for 72 h or more, or was admitted to intensive care, or died at the hospital, was transferred into the hospital for specialist care, was transferred to another hospital for specialist care or for an intensive care bed and whose isolated injuries met a set of criteria. Data extracted included: age, gender, mode of arrival, location of injuries including: hand and/or wrist and mechanism of injury. We performed a logistic regression analysis to assess the association between hand/wrist injury to ISS score of 15 points or above/below and to the presentation of other injuries. RESULTS: 107 patients were analysed. Hand and wrist injuries were the second most common injury (26.2%), after thoracic injuries. Distal radial injuries were found in 5.6%, carpal/carpometacarpal in 6.5%, concurrent distal radius and carpometacarpal in 0.9%, phalangeal injuries in 4.7%, tendon injuries in 0.9% and concurrent hand and wrist injuries in 7.5% cases. There was a significant association between hand or wrist injuries and lower limb injuries (Odds Ratio (OR): 3.84; 95% confidence intervals (CI): 1.09 to 13.50; p = 0.04) and pelvic injuries (OR: 4.78; 95% CI: 1.31 to 17.44; p = 0.02). There was no statistical association between hand and wrist injuries and ISS score (OR: 0.80; 95% CI: 0.11 to 5.79; p = 0.82). CONCLUSIONS: Hand and wrist injuries are prevalent in trauma patients admitted to MTCs. They should not be under-estimated but routinely screened for in multiply injured patients particularly those with a pelvic or lower limb injury.

Flow speed alters the apparent size and concentration of particles measured using NanoSight nanoparticle tracking analysis.

Nanoparticle tracking analysis (NTA) is commonly used to count and size nano-sized particles. A sample loading pump can be used to analyse a larger sample volume, but it is unclear whether accuracy is affected. Using a NanoSight NS300 with the manufacturer-supplied pump, we examined synthetic silica and latex microspheres, liposomes and placental extracellular vesicles at different flow speeds. Analysis at flow speeds of 20 or 50 significantly reduced the measured concentration and mean/modal size of particles, particularly for mono-dispersed samples. We identify sample flow speed as a crucial instrument setting which should be reported in all studies that use NTA.

Emmetropia approach dynamics with diurnal dual-phase cycling.

Numerical experiments are performed on a first order exponential response function subjected to a diurnal square wave visual environment with variable duty cycle. The model is directly applicable to exponential drift of focal status. A two-state square wave is employed as the forcing function with high B for time H and low A for time L. Duty cycles of (1/3), (1/2) and (2/3) are calculated in detail. Results show the following standard linear system response: (1) Unless the system runs into the stops, the ready state equilibrium settling level is always between A and B. The level is linearly proportional to a time-weighted average of the high and low states. (2) The effective time constant t(eff) varies hyperbolically with duty cycle. For DC = (1/3) and t1 = 100 days, the effective time constant is lengthened to 300 days. An asymptote is encountered under certain circumstances where t(eff) approaches infinity. (3) Effective time constants and steady state equilibria are independent of square wave frequency f, animal time constant t1, magnitude and sign of A & B, and diurnal sequencing of the highs and lows. By presenting results on dimensionless coordinates, we can predict the drift rates of some animal experiments. Agreement between theory and experiments has a correlation coefficient r = 0.97 for 12 Macaca nemestrina eyes.