Aerospace medicine and human performance最新文献

Introduction: Habituation to motion has therapeutic applications for motion sickness desensitization and rehabilitation of patients with vestibular disease. Less attention has been devoted to the opposite process: sensitization.

Methods: Subjects (N = 50) were randomly allocated to four sequences: Baseline visual stimulus; then 15 min of time gap; cross-coupled motion (C-C) or a Control condition; then a time gap of 15 min or 2 h; then a retest visual stimulus. Motion exposures were for 10 min or until moderate nausea, whichever was sooner. The visual stimulus was a scene rotating in yaw at 0.2 Hz with superimposed "wobble". C-C was whole-body rotation on a turntable with eight 45° head tilts during each 30-s period. Control was head tilt without rotation. Rotational velocity was incremented in staircase steps of 3° · s-1 every 30 s.

Results: Groups were equivalent for Total Motion Sickness Symptom scores elicited by the first visual stimulus (combined: mean ± SD 10.8 ± 8.4). C-C produced greater Total Symptoms (20.3 ± 6.8) than Control (3.1 ± 3.7). Subjects recovered subjectively from C-C before retest of visual stimulus. For the retest visual stimulus, Total Symptoms were higher following C-C (15.1 ± 9.0) than following Control (8.3 ± 7.1) for both the 15 min and 2 h retests. Sickness ratings (SR) mirrored these effects of C-C.

Discussion: C-C motion sensitized subsequent responses to visual stimulation up to 2 h later. Sensitization of visual stimulation crossed modalities and appeared subconscious since it occurred despite subjective recovery from C-C. For some individuals, a previously relatively innocuous visual stimulus became nauseogenic on retest. The results have implications for the use of visual technologies within hours of exposure to provocative motion. Golding JF, Alund D, Gresty MA, Flynn MB. Sensitization of visually induced motion sickness by prior provocative physical motion. Aerosp Med Hum Perform. 2024; 95(10):741-748.

Background: Stroke in young patients is frequently associated with a patent foramen ovale (PFO). Controversy exists over whether the PFO is a cause, a risk factor, or an incidental finding. Estimating the individualized risk of stroke recurrence has been difficult to ascertain. This has implications for aeromedical certification for pilots following stroke recovery.

Case report: A 28-yr-old male flight instructor presented with sudden onset unilateral facial paresthesia, hand weakness, and blurred vision, accompanied by gradual onset bilateral headache. While the cranial symptoms resolved, left hand weakness persisted for 3 d. MRI revealed two punctate ischemic foci in the right precentral gyrus and superior parietal lobe. A transesophageal echocardiogram revealed a PFO with a small bidirectional shunt. His cardiologist and neurologist advised the PFO was unlikely to have caused his stroke and estimated an annual recurrence rate of < 1.8%. He was treated medically and declined PFO closure. He was able to return to flying light-sport aircraft. However, an enduring copilot restriction for general aviation activities was placed on his Class 1 and 2 medical certificates.

Discussion: This case highlights the difficulty in determining individualized recurrence risks for pilots recovering from a stroke associated with a PFO. While medical treatment does reduce the risk of recurrence, PFO closure provides marginal additional benefit in certain patients with a risk of side effects. Contemporary evidence-based risk scoring systems combined with echocardiography findings may be used together to better risk stratify patients and suitability for medical aviation recertification. Rengel AC, Gericke C. Embolic ischemic cortical stroke in a young flight instructor with a small patent foramen ovale. Aerosp Med Hum Perform. 2024; 95(10):784-787.

Introduction: Hypoxia training is mandatory for military pilots, but variability in hypoxia symptoms challenges the training. In a previous study we showed that 64% of pilots recognized hypoxia faster in their second normobaric hypoxia session conducted 2.4 yr after the first. Our aim here was to evaluate whether a third session conducted 5.0 yr after the first would provide further benefit.

Methods: This study was conducted under normobaric conditions in a tactical F/A-18C Hornet simulator in three sessions in which the pilots performed visual identification missions and breathed 21% oxygen in nitrogen. The breathing gas was changed to a hypoxic mixture containing either 8%, 7%, or 6% oxygen in nitrogen without the pilot's knowledge. Data were collected from 102 military pilots. The primary outcome was the time taken for initial identification of hypoxia symptoms.

Results: Hypoxia symptoms were recognized on average in the first session in 8% oxygen in 100 s, 7% oxygen in 90 s, and 6% oxygen in 78 s; in the second in 87 s, 80 s, and 71 s, respectively; and in the third in 79 s, 67 s, and 64 s, respectively. In 2 sessions 20 pilots and in each 3 training sessions 3 pilots had slow recognition times.

Discussion: Hypoxia symptom recognition improved the further the repeated normobaric hypoxia training went. More emphasis should be put on the 23% group of slow hypoxia symptom recognizers and more customized hypoxia training for them should be offered. Leinonen AM, Varis NO, Kokki HJ, Leino TK. Normobaric hypoxia symptom recognition in three training sessions. Aerosp Med Hum Perform. 2024; 95(10):758-764.

INTRODUCTION: On-board medical emergencies are increasing. Different geographies have different legislation and requirements for medical emergency kits and first aid kits. A comprehensive review to compare the contents of both kits was conducted, including the International Air Transport Association, European Union Aviation Safety Agency, and Federal Aviation Administration, as well as some from other geographical areas of the globe to cover continents and regions with the highest air traffic, such as Brazil, Kenya, Australia, and Taiwan.METHODS: On June 10, 2023, a search was conducted using standardized medical terms (medical subject headings) within the PubMed^® database. The relevant terms identified were "Aircraft" and "Medical Emergencies"; articles published within the last 10 yr were filtered. Subsequently, even articles published before 2013 were consulted if cited by the initial ones. The main regulatory entities' documentation was found using the Google search engine and consulted.CONCLUSIONS: It is impossible to be prepared for every emergency on board. Still, as doctors, we have a moral and ethical obligation to try to improve the outcomes of those emergencies. Getting a standardized report of every on-board emergency is crucial. That would make optimizing the items to include in the emergency and first aid kits easier. There are many similarities among the compared entities, but essential differences have been found. There is room for improvement, especially for pediatric travelers.Oliveira ATB. Worldwide regulation of the medical emergency kit and first aid kit. Aerosp Med Hum Perform. 2024; 95(6):321-326.