Browsing by Author "Smith, Jason E"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Open Access
    Assessing spinal movement during four extrication methods: a biomechanical study using healthy volunteers
    (2022-01-15) Nutbeam, Tim; Fenwick, Rob; May, Barbara; Stassen, Willem; Smith, Jason E; Bowdler, Jono; Wallis, Lee; Shippen, James
    Background Motor vehicle collisions are a common cause of death and serious injury. Many casualties will remain in their vehicle following a collision. Trapped patients have more injuries and are more likely to die than their untrapped counterparts. Current extrication methods are time consuming and have a focus on movement minimisation and mitigation. The optimal extrication strategy and the effect this extrication method has on spinal movement is unknown. The aim of this study was to evaluate the movement at the cervical and lumbar spine for four commonly utilised extrication techniques. Methods Biomechanical data was collected using inertial Measurement Units on 6 healthy volunteers. The extrication types examined were: roof removal, b-post rip, rapid removal and self-extrication. Measurements were recorded at the cervical and lumbar spine, and in the anteroposterior (AP) and lateral (LAT) planes. Total movement (travel), maximal movement, mean, standard deviation and confidence intervals are reported for each extrication type. Results Data from a total of 230 extrications were collected for analysis. The smallest maximal and total movement (travel) were seen when the volunteer self-extricated (AP max = 2.6 mm, travel 4.9 mm). The largest maximal movement and travel were seen in rapid extrication extricated (AP max = 6.21 mm, travel 20.51 mm). The differences between self-extrication and all other methods were significant (p < 0.001), small non-significant differences existed between roof removal, b-post rip and rapid removal. Self-extrication was significantly quicker than the other extrication methods (mean 6.4 s). Conclusions In healthy volunteers, self-extrication is associated with the smallest spinal movement and the fastest time to complete extrication. Rapid, B-post rip and roof off extrication types are all associated with similar movements and time to extrication in prepared vehicles.
  • Thumbnail Image
    Item
    Open Access
    Major incident triage: development and validation of a modified primary triage tool
    (2018) Vassallo, James M A; Smith, Jason E; Wallis, Lee A
    Introduction A key principle in the effective management of a major incident is triage, prioritising patients on the basis of their clinical acuity. However, existing methods of primary major incident triage demonstrate poor performance at identifying the Priority One patient in need of a life-saving intervention. The aim of this thesis was to derive an improved triage tool. Methods The first part of the thesis defined what constitutes a life-saving intervention. Then using a retrospective military cohort, the optimum physiological thresholds for identifying the need for life-saving intervention were determined; the combination of which was used to define the Modified Physiological Triage Tool (MPTT). The MPTT was validated using a large civilian trauma database and a prospective military cohort. Subsequently, to describe the safety profile of the MPTT, an analysis of the implications of under-triage was undertaken. Finally, pragmatic changes were made to the MPTT (MPTT-24) - in order to provide a more useable method of primary triage. Statistical analysis was conducted using sensitivities and specificities, with triage tool performance compared using a McNemar test. Results 32 interventions were considered life-saving and the optimum physiological thresholds to identify these were a GCS <14, 12 < RR <22 and a HR < 100. Within both the military and civilian populations, the MPTT outperformed all existing methods of triage with the greatest sensitivity and lowest rates of under-triage, but at the expense of over-triage. Applying pragmatic changes, the MPTT-24 had comparable performance to the MPTT and continued to outperform existing methods. Conclusion The priority of primary major incident triage is to identify patients in need of life-saving intervention and to minimise under-triage. Fulfilling these priorities, the MPTT-24 outperforms existing methods of triage and its use is recommended as an alternative to existing methods of primary major incident triage. The MPTT-24 also offers a theoretical reduction in time required to triage and uses a simplified conscious level assessment, thus allowing it to be used by less experienced providers.
  • Thumbnail Image
    Item
    Open Access
    The role of cervical collars and verbal instructions in minimising spinal movement during self-extrication following a motor vehicle collision - a biomechanical study using healthy volunteers
    (2021-07-31) Nutbeam, Tim; Fenwick, Rob; May, Barbara; Stassen, Willem; Smith, Jason E; Wallis, Lee; Dayson, Mike; Shippen, James
    Background Motor vehicle collisions account for 1.3 million deaths and 50 million serious injuries worldwide each year. However, the majority of people involved in such incidents are uninjured or have injuries which do not prevent them exiting the vehicle. Self-extrication is the process by which a casualty is instructed to leave their vehicle and completes this with minimal or no assistance. Self-extrication may offer a number of patient and system-wide benefits. The efficacy of routine cervical collar application for this group is unclear and previous studies have demonstrated inconsistent results. It is unknown whether scripted instructions given to casualties on how to exit the vehicle would offer any additional utility. The aim of this study was to evaluate the effect of cervical collars and instructions on spinal movements during self-extrication from a vehicle, using novel motion tracking technology. Methods Biomechanical data on extrications were collected using Inertial Measurement Units on 10 healthy volunteers. The different extrication types examined were: i) No instructions and no cervical collar, ii) No instructions, with cervical collar, iii) With instructions and no collar, and iv) With instructions and with collar. Measurements were recorded at the cervical and lumbar spine, and in the anteroposterior (AP) and lateral (LAT) planes. Total movement, mean, standard deviation and confidence intervals are reported for each extrication type. Results Data were recorded for 392 extrications. The smallest cervical spine movements were recorded when a collar was applied and no instructions were given: mean 6.9 mm AP and 4.4 mm LAT. This also produced the smallest movements at the lumbar spine with a mean of 122 mm AP and 72.5 mm LAT. The largest overall movements were seen in the cervical spine AP when no instructions and no collar were used (28.3 mm). For cervical spine lateral movements, no collar but with instructions produced the greatest movement (18.5 mm). For the lumbar spine, the greatest movement was recorded when instructions were given and no collar was used (153.5 mm AP, 101.1 mm LAT). Conclusions Across all participants, the most frequently occurring extrication method associated with the least movement was no instructions, with a cervical collar in situ.