Preservation of cognitive performance with age during exertional heat stress under low and high air velocity

Older adults may be at greater risk for occupational injuries given their reduced capacity to dissipate heat, leading to greater thermal strain and potentially cognitive decrements. Purpose. To examine the effects of age and increased air velocity, during exercise in humid heat, on information processing and attention. Methods. Nine young (24 \ub1 1 years) and 9 older (59 \ub1 1 years) males cycled 4 7 15 min (separated by 15 min rest) at a fixed rate of heat production (400 W) in humid heat (35\ub0C, 60% relative humidity) under 0.5 (low) and 3.0 (high) m \ub7 s-1 air velocity wearing coveralls. At rest, immediately following exercise (end exercise), and after the final recovery, participants performed an abbreviated paced auditory serial addition task (PASAT, 2 sec pace). Results. PASAT numbers of correct responses at end exercise were similar for young (low = 49 \ub1 3; high = 51 \ub1 3) and older (low = 46 \ub1 5; high = 47 \ub1 4) males and across air velocity conditions, and when scored relative to age norms. Psychological sweating, or an increased sweat rate with the administration of the PASAT, was observed in both age groups in the high condition. Conclusion. No significant decrements in attention and speeded information processing were observed, with age or altered air velocity, following intermittent exercise in humid heat.Peer reviewed: YesNRC publication: Ye

Evaluating probability of detection using an airborne multi-sensor system for search and rescue operations: a human factors flight test evaluation

A large scale airborne experiment was performed in order to evaluate the visual detection performance of operators while using an advanced sensor system for Search and Rescue tasks. Such an evaluation is timely due to the Government of Canada\u2019s intent to replace its aging Fixed-Wing Search and Rescue aircraft with a more advanced, sensor-equipped fleet. The experiment involved 22 hours of night time flight trials using an infrared sensor system performing a search pattern over an idealized trial range. Ninety search objects resembling downed, fixed wing, general aviation aircraft were placed within a 21 km by 13 km grassland area to compose the trial range. The rate of detection was found to be 81.8% based on 978 total detection opportunities, across two sensor operators.Peer reviewed: YesNRC publication: Ye

The marriage of surgical simulation and telementoring for damage-control surgical training of operational first responders : a pilot study

BACKGROUND: Hemorrhage is the leading cause of preventable posttraumatic death. Many such deaths may be potentially salvageable with remote damage-control surgical interventions. As recent innovations in information technology enable remote specialist support to point-of-care providers, advanced interventions, such as remote damage-control surgery, may be possible in remote settings. METHODS: An anatomically realistic perfused surgical training mannequin with intrinsic fluid loss measurements (the \u201cCut Suit\u201d) was used to study perihepatic packing with massive liver hemorrhage. The primary outcome was loss of simulated blood (water) during six stages, namely, incision, retraction, direction, identification, packing, and postpacking. Six fully credentialed surgeons performed the same task as 12 military medical technicians who were randomized to remotely telementored (RTM) (n = 7) or unmentored (UTM) (n=5) real-time guidance by a trauma surgeon. RESULTS: There were no significant differences in fluid loss between the surgeons and the UTM group or between the UTM and RTM groups. However, when comparing the RTM group with the surgeons, there was significantly more total fluid loss (p = 0.001) and greater loss during the identification (p = 0.002), retraction (p = 0.035), direction (p = 0.014), and packing(p = 0.022) stages. There were no significant differences in fluid loss after packing between the groups despite differences in the number of sponges used; RTM group used more sponges than the surgeons and significantly more than the UTM group (p = 0.048). However, mentoring significantly increased self-assessed nonsurgeon procedural confidence (p = 0.004). CONCLUSION: Perihepatic packing of an exsanguinating liver hemorrhage model was readily performed by military medical technicians after a focused briefing. While real-time telementoring did not improve fluid loss, it significantly increased nonsurgeon procedural confidence, which may augment the feasibility of the concept by allowing them to undertake psychologically daunting procedures.This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.Peer reviewed: YesNRC publication: Ye