Correlation between observation task performance and visual acuity, contrast sensitivity and environmental light in a simulated maritime study.

PURPOSE: To examine the relevance of visual acuity (VA) and index of contrast sensitivity (ICS) as predictors for visual observation task performance in a maritime environment. METHODS: Sixty naval cadets were recruited to a study on observation tasks in a simulated maritime environment under three different light settings. Their ICS were computed based on contrast sensitivity (CS) data recorded by Optec 6500 and CSV-1000E CS tests. The correlation between object identification distance and VA/ICS was examined by stepwise linear regression. RESULTS: The object detection distance was significantly correlated to the level of environmental light (p < 0.001), but not to the VA or ICS recorded in the test subjects. Female cadets had a significantly shorter target identification range than the male cadets. CONCLUSION: Neither CS nor VA were found to be significantly correlated to observation task performance. This apparent absence of proven predictive value of visual parameters for observation tasks in a maritime environment may presumably be ascribed to the normal and uniform visual capacity in all our study subjects.

Mountain rescue cardiopulmonary resuscitation: a comparison between manual and mechanical chest compressions during manikin cardio resuscitation.

AIM: Chest compression devices are useful during mountain rescue but may cause a delay in transport if not immediately available. The aims of this prospective observational study were to compare manual and mechanical cardiopulmonary resuscitation (CPR) during transport on a sledge connected to a snowmobile with a non-moving setting and to compare CPR quality between manual and two mechanical chest compression devices. METHODS: Sixteen healthcare providers simulated four different combined CPR scenarios on a sledge in a non-moving setting and during transport and two mechanical chest compression devices during transport on the sledge. The study was conducted in May 2015 in a mountain in Norway. The primary outcome measures were compression rate (compressions per minute), compression depth in millimetres, leaning (incomplete chest wall release after compression in millimetres) and chest compression fraction (fraction of total time were compression were performed). The results were analysed by descriptive and graphical methods and paired t-tests were used to compare the differences between techniques. RESULTS: We did not observe a significant difference between moving and non-moving conditions with respect to manual compression rate (p=0.34), compression depth (p=0.50) or leaning (p=0.92). However, both the manual compression depth (p<0.001) and the leaning (p=0.04) showed a significantly larger variance during the moving runs. CONCLUSION: Manual chest compression is possible on a snowmobile during transport even in challenging terrain. This experimental study shows that high-quality chest compressions and manual ventilation can be performed in an intubated patient during a short-term transportation on a sledge.

Is upper limb virtual reality training more intensive than conventional training for patients in the subacute phase after stroke? An analysis of treatment intensity and content.

BACKGROUND: Virtual reality (VR) training is thought to improve upper limb (UL) motor function after stroke when utilizing intensive training with many repetitions. The purpose of this study was to compare intensity and content of a VR training intervention to a conventional task-oriented intervention (CT). METHODS: A random sample of 50 video recordings was analyzed of patients with a broad range of UL motor impairments (mean age 61y, 22 women). Patients took part in the VIRTUES trial and were randomized to either VR or CT and stratified according to severity of paresis. A standardized scoring form was used to analyze intensity, i.e. active use of the affected UL expressed in % of total time, total active time and total duration of a training session in minutes, content of training and feedback. Two raters collected data independently. Linear regression models as well as descriptive and graphical methods were used. RESULTS: Patients in the VR group spent significantly more time actively practicing with an activity rate of 77.6 (8.9) % than patients in the CT 67.3 (13.9) %, (p = .003). This difference was attributed to the subgroup of patients with initially severe paresis (n = 22). While in VR severely impaired patients spent 80.7 % (4.4 %) of the session time actively; they reached 60.6 (12.1) % in CT. VR and CT also differed in terms of tasks and feedback provided. CONCLUSION: Our results indicate that patients with severely impaired UL motor function spent more time actively in VR training, which may influence recovery. The upcoming results of the VIRTUES trial will show whether this is correlated with an increased effect of VR compared to CT. TRIAL REGISTRATION: ClinicalTrials.gov NCT02079103 , February 27, 2014.