Effect of vacuum spine board immobilization on incidence of pressure ulcers during evacuation of military casualties from theater

Understanding occipital pressure sores in UK military casualties: a pilot study in healthy military personnel

INTRODUCTION

The high prevalence of occipital ulcers in UK military casualties observed during the conflict in Afghanistan is a multifactorial phenomenon. However, the consensus is that ulceration is triggered by excessive pressure that is maintained for too long during the use of the general service military stretcher. Thresholds for capillary occlusion are accepted benchmarks to define excessive pressure, but similar thresholds for safe/excessive duration of pressure application do not exist. To address this gap in knowledge, we propose to use the time it takes for a healthy person to feel pain at the back of the head as an initial indication of safe exposure to pressure.

METHODS

Healthy military personnel (16 male/10 female) were asked to lie motionless on a typical general service stretcher until they felt pain. Time-to-pain and the location of pain were recorded. To support the interpretation of results, baseline sensitivity to pain and pressure distribution at the back of the head were also measured. Independent samples t-test was used to assess differences between genders.

RESULTS

Twenty participants felt pressure-induced soft-tissue pain at the back of the head. The remaining six participants terminated the test due to musculoskeletal pain caused by poor ergonomic positioning. On average, pain at the occiput developed after 31 min (±14 min). Female participants were significantly more sensitive to pain (t(24)=3.038,p=0.006), but time-to-pain did not differ significantly between genders (p>0.05).

CONCLUSIONS

When people lie motionless on a typical military stretcher, the back of the head is the first area of the body that becomes painful due to pressure. The fact that pain develops in ≈30 min can help healthcare providers decide how frequently to reposition their patients who are unable to do this on their own. More research is still needed to directly link time-to-pain with time-to-injury.

Prevention of pressure injuries during military aeromedical evacuation or prolonged field care: A randomized trial

BACKGROUND

During military aeromedical evacuation (AE) and prolonged field care (PFC), casualties are at increased pressure injury (PI) risk. Operational PI mitigation strategies research is limited.

PURPOSE

Using multiple factors, this study examined Mepilex/LiquiCell effects on PI risk under simulated AE/PFC.

METHODS

Healthy adults were stratified by body fat (%) and randomized to six groups on three surfaces. Set A: Warrior Evacuation Litter Pad (WELP) with/without Mepilex; Set B: Vacuum Spine Board (VSB) with/without Mepilex; Set C: Talon litter with/without LiquiCell. Two hours supine (loaded) was needed.

OUTCOMES

Sacral skin transcutaneous tissue oxygen (TcPO2), temperature, moisture, interface pressure, interleukin-1α/Total Protein.

FINDINGS

54 participants. Sets A/B: No Mepilex effects; temperature increased 2.5°C. Set C: No LiquiCell effects. Significant ΔTcPO2 (unloaded-loaded), with 100% impaired perfusion; temperature increased 1.2°C.

DISCUSSION

Multiple risk factors for PI mitigating strategies must consider. Talon with increased pressure/impaired perfusion but smaller temperature/moisture changes; WELP/VSB with increased temperature/moisture but lower pressure/adequate perfusion.

Overview of the MEMS Pirani Sensors

Vacuum equipment has a wide range of applications, and vacuum monitoring in such equipment is necessary in order to meet practical applications. Pirani sensors work by using the effect of air density on the heat conduction of the gas to cause temperature changes in sensitive structures, thus detecting the pressure in the surrounding environment and thus vacuum monitoring. In past decades, MEMS Pirani sensors have received considerable attention and practical applications because of their advances in simple structures, long service life, wide measurement range and high sensitivity. This review systematically summarizes and compares different types of MEMS Pirani sensors. The configuration, material, mechanism, and performance of different types of MEMS Pirani sensors are discussed, including the ones based on thermistors, thermocouples, diodes and surface acoustic wave. Further, the development status of novel Pirani sensors based on functional materials such as nanoporous materials, carbon nanotubes and graphene are investigated, and the possible future development directions for MEMS Pirani sensors are discussed. This review is with the purpose to focus on a generalized knowledge of MEMS Pirani sensors, thus inspiring the investigations on their practical applications.

French recommendations for the management of patients with spinal cord injury or at risk of spinal cord injury

OBJECTIVES

To update the French guidelines on the management of trauma patients with spinal cord injury or suspected spinal cord injury.

DESIGN

A consensus committee of 27 experts was formed. A formal conflict-of-interest (COI) policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised.

METHODS

The committee studied twelve questions: (1) What are the indications and arrangements for spinal immobilisation? (2) What are the arrangements for pre-hospital orotracheal intubation? (3) What are the objectives of haemodynamic resuscitation during the lesion assessment, and during the first few days in hospital? (4) What is the best way to manage these patients to improve their long-term prognosis? (5) What is the place of corticosteroid therapy in the initial phase? (6) What are the indications for magnetic resonance imaging in the lesion assessment phase? (7) What is the optimal time for surgical management? (8) What are the best arrangements for orotracheal intubation in the hospital environment? (9) What are the specific conditions for weaning these patients from mechanical ventilation for? (10) What are the procedures for analgesic treatment of these patients? (11) What are the specific arrangements for installing and mobilising these patients? (12) What is the place of early intermittent bladder sampling in these patients? Each question was formulated in a PICO (Patients, Intervention, Comparison, Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® Methodology.

RESULTS

The experts' work synthesis and the application of the GRADE method resulted in 19 recommendations. Among the recommendations formalised, 2 have a high level of evidence (GRADE 1+/-) and 12 have a low level of evidence (GRADE 2+/-). For 5 recommendations, the GRADE method could not be applied, resulting in expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations.

CONCLUSIONS

There was significant agreement among experts on strong recommendations to improve practices for the management of patients with spinal cord injury.

Severe pressure ulcers requiring surgery impair the functional outcome after acute spinal cord injury

STUDY DESIGN

Retrospective matched cohort study.

OBJECTIVES

Assessing the influence of surgically managed grade 3 and 4 pressure ulcers (PU) in the acute phase after spinal cord injury (SCI) on the neurological and functional outcome after 1 year.

SETTING

Specialized SCI-unit within a level 1 trauma center in Murnau, Germany.

METHODS

We performed a retrospective matched cohort study. For every patient with acute SCI and a PU requiring surgery, we identified matched controls within our database in a 1:3 ratio. Matching criteria were: AIS-grade (American Spinal Injury Association Impairment Scale), neurological level and age. The scores of the SCIM-III (Spinal Cord Independence Measure) and the ISNCSCI (International Standards for Neurological Classification of Spinal Cord Injury) as well as the total length of stay (LOS) at the hospital were used as outcome parameters. We applied a stratified analysis using a conditional logistic regression to test for group differences in each outcome parameter of the study.

RESULTS

In a 6-year period (2010-2015) 28 patients required flap surgery due to 3-4° PU in the acute phase after SCI. Of these patients, 15 had complete data sets according to the EMSCI (European Multicenter Study about Spinal Cord Injury) protocol. Patients with severe PUs during the acute SCI phase had a significantly impaired functional outcome. After 1 year the improvement of the SCIM score was significantly lower in the PU group compared to the control group (17.4 versus 30.5; p < 0.006). However, the change in AIS grade after 1 year was not significantly affected. The LOS was prolonged by a mean of 48 days in the PU group (p < 0.006).

CONCLUSIONS

Severe PUs requiring surgery in the acute phase after SCI impair the functional outcome and increase LOS. Preventive measures should be applied to all acute SCI patients. Patients should be transferred to specialized SCI-centers as soon as possible.

Cervical and Thoracolumbar Spine Injury Evaluation, Transport, and Surgery in the Deployed Setting

This Cervical and Thoracolumbar Spine Injury Evaluation, Transport, and Surgery Clinical Practice Guideline (CPG) is designed to provide guidance to the deployed provider when they are treating a combat casualty who has sustained a spine or spinal cord injury. The CPG objective for the treatment and the movement of these patients is to maintain spinal stability through transport, perform decompression when urgently needed, achieve definitive stabilization when appropriate, avoid secondary injury, and prevent deterioration of the patient's neurological condition. Thorough and accurate documentation of the patient's neurological examination is crucial to ensure appropriate management decisions are made as the patient transits through the evacuation system. The use of this CPG should be in conjunction with good clinical judgment.

Chinese expert consensus on the treatment of modern combat-related spinal injuries

The battlefield treatments of spinal and spinal cord injury vary from civilian settings. However, there is no unified battlefield treatment guidelines for spine trauma in PLA. An expert consensus is reached, based on spine trauma epidemiology and the concepts of battlefield treatment combined with the existing levels of military medical care in modern warfare. Since the specialized treatment for spine trauma are no significant difference between civilian settings and modern war, the first aid, emergency treatment and early treatment of spine trauma are introduced separately in three levels in this consensus. In Level I facilities, the fast and accurate evaluation of spine trauma followed by fixation and stabilization are recommended during the first-aid stage. Re-evaluation, further treatment for possible hemorrhagic shock, dyspnea and infection are recommended at Level II facilities. At Level III facilities, it is recommended to strengthen the intensive care and the prevention of urinary system and lung infection for the wounded with severe spinal injury, however, spinal surgery is not recommended in a battlefield hospital. The grading standard for evidence evaluation and recommendation was used to reach this expert consensus.

Comparing the Efficacy of Methods for Immobilizing the Cervical Spine

STUDY DESIGN

This was a prospective simulator study with 16 healthy male subjects.

OBJECTIVE

The aim of this study was to compare the relative efficacy of immobilization systems in limiting involuntary movements of the cervical spine using a dynamic simulation model.

SUMMARY OF BACKGROUND DATA

Relatively few studies have tested the efficacy of immobilization methods for limiting involuntary cervical movement, and only one of these studies used a dynamic simulation system to do so.

METHODS

Immobilization configurations tested were cot alone, cot with cervical collar, long spine board (LSB) with cervical collar and head blocks, and vacuum mattress (VM) with cervical collar. A motion platform reproduced shocks and vibrations from ambulance and helicopter field rides, as well as more severe shocks and vibrations that might be encountered on rougher terrain and in inclement weather (designated as an "augmented" ride). Motion capture technology quantitated involuntary cervical rotation, flexion/extension, and lateral bend. The mean and 95% confidence interval of the mean were calculated for the root mean square of angular changes from the starting position and for the maximum range of motion.

RESULTS

All configurations tested decreased cervical rotation and flexion/extension relative to the cot alone. However, the LSB and VM were significantly more effective in decreasing cervical rotation than the cervical collar, and the LSB decreased rotation more than the VM in augmented rides. The LSB and VM, but not the cervical collar, significantly limited cervical lateral bend relative to the cot alone.

CONCLUSION

Under the study conditions, the LSB and the VM were more effective in limiting cervical movement than the cervical collar. Under some conditions, the LSB decreased repetitive and acute movements more than the VM. Further studies using simulation and other approaches will be essential for determining the safest, most effective configuration should providers choose to immobilize patients with suspected spinal injuries.

LEVEL OF EVIDENCE

3.

Comparing the Efficacy of Methods for Immobilizing the Thoracic-Lumbar Spine

OBJECTIVE

The purpose of this study was to compare the relative efficacy of immobilization systems in limiting thoracic-lumbar movements.

METHODS

A dynamic simulation system was used to reproduce transport-related shocks and vibration, and involuntary movements of the thoracic-lumbar region were measured using 3 immobilization configurations.

RESULTS

The vacuum mattress and the long spine board were generally more effective than the cot alone in reducing thoracic-lumbar rotation and flexion/extension. However, the vacuum mattress reduced these thoracic-lumbar movements to a greater extent than the long spine board. In addition, the vacuum mattress significantly decreased thoracic-lumbar lateral movement relative to the cot alone under all simulated transport conditions. In contrast, the long spine board allowed greater lateral movement than the cot alone in a number of the simulated transport rides.

CONCLUSION

Under the study conditions, the vacuum mattress was more effective for limiting involuntary movements of the thoracic-lumbar region than the long spine board. Moreover, the increased lateral bend observed with the long spine board under some conditions suggests it may be inadequate for immobilizing this anatomic region as presently designed. Should emergency medical service providers choose to immobilize patients with suspected injuries of the thoracic-lumbar spine, study results support the use of the vacuum mattress.

The Norwegian guidelines for the prehospital management of adult trauma patients with potential spinal injury

The traditional prehospital management of trauma victims with potential spinal injury has become increasingly questioned as authors and clinicians have raised concerns about over-triage and harm. In order to address these concerns, the Norwegian National Competence Service for Traumatology commissioned a faculty to provide a national guideline for pre-hospital spinal stabilisation. This work is based on a systematic review of available literature and a standardised consensus process. The faculty recommends a selective approach to spinal stabilisation as well as the implementation of triaging tools based on clinical findings. A strategy of minimal handling should be observed.

Comparison of tissue-interface pressure in healthy subjects lying on two trauma splinting devices: The vacuum mattress splint and long spine board

BACKGROUND

Most emergency transport protocols in the United States currently call for the use of a spine board (SB) to help immobilize the trauma patient. However, there are concerns that their use is associated with a risk of pressure ulcer development. An alternative device, the vacuum mattress splint (VMS) has been shown by previous investigations to be a viable alternative to the SB, but no single study has explicated the tissue-interface pressure in depth.

METHODS

To determine if the VMS will exert less pressure on areas of the body susceptible to pressure ulcers than a SB we enrolled healthy subjects to lie on the devices in random order while pressure measurements were recorded. Sensors were placed underneath the occiput, scapulae, sacrum, and heels of each subject lying on each device. Three parameters were used to analyze differences between the two devices: 1) mean pressure of all active cells, 2) number of cells exceeding 9.3kPa, and 3) maximal pressure (Pmax).

RESULTS

In all regions, there was significant reduction in the mean pressure of all active cells in the VMS. In the number of cells exceeding 9.3kPa, we saw a significant reduction in the sacrum and scapulae in the VMS, no difference in the occiput, and significantly more cells above this value in the heels of subjects on the VMS. Pmax was significantly reduced in all regions, and was less than half when examining the sacrum (104.3 vs. 41.8kPa, p<0.001).

CONCLUSION

This study does not exclude the possibility of pressure ulcer development in the VMS although there was a significant reduction in pressure in the parameters we measured in most areas. These results indicate that the VMS may reduce the incidence and severity of pressure ulcer development compared to the SB. Further prospective trials are needed to determine if these results will translate into better clinical outcomes.

Ergonomics intervention on an alternative design of a spinal board

A spinal board is the evacuation tool of first aid to help the injured spinal cord. The existing spinal board has several weaknesses, both in terms of user comfort and the effectiveness and efficiency of the evacuation process. This study designs an ergonomic spinal board using the quality function deployment approach. A preliminary survey was conducted through direct observation and interviews with volunteers from the Indonesian Red Cross. Data gathered were translated into a questionnaire and answered by 47 participants in West Sumatra. The results indicate that the selection of materials, the application of strap systems as well as the addition of features are very important in designing an ergonomic spinal board. The data were used in designing an ergonomic spinal board. The use of anthropometric data ensures that this product can accommodate safety and comfort when immobilized, as well as the flexibility and speed of the rescue evacuation process.