Spinal motion restriction: an educational and implementation program to redefine prehospital spinal assessment and care

Radiographic cervical spine injury patterns in admitted blunt trauma patients with and without prehospital spinal motion restriction

Objectives

Selective prehospital cervical spine motion restriction (C-SMR) following blunt trauma has increasingly been used by emergency medical service (EMS) providers. We determined rates of prehospital C-SMR and concomitant radiographic injury patterns.

Methods

A retrospective trauma registry and chart review was conducted for all adult blunt trauma patients who were transported by EMS and hospitalized with radiographic cervical spine injuries from 2011 to 2019 at a level 1 trauma center.

Results

Of 658 admitted blunt trauma patients with confirmed cervical spine injury by imaging, 117 (17.8%) did not receive prehospital C-SMR. Patients without prehospital C-SMR were significantly older (76 vs 54 years), more often had low fall as mechanism of injury (59.8% vs 15.9%) and had lower Injury Severity Score (10 vs 17). Patients without C-SMR (Non-SMR) experienced the full array of cervical spine injury types and locations. While the non-SMR patients most often had dens fractures,C-SMR patients most often had C7 fractures; frequencies of fractures at the remaining vertebral levels were comparable. On MRI, cervical spinal cord (8.5% vs 19.6%) and ligamentous injuries (5.1% vs 12.6%) occurred less often in non-SMR patients. Approximately 8.5% of non-SMR patients and 20% of C-SMR patients required cervical spine surgery.

Conclusion

Patients without prehospital C-SMR demonstrate a broad array of cervical spine injuries. While the rates of certain cervical injuries are lower in prehospital non-SMR patients, they are not insignificant.

Level of evidence

Level III.

Patterns of change in prehospital spinal motion restriction: A retrospective database review

BACKGROUND

Acute management of trauma patients with potential spine injuries has evolved from uniform spinal immobilization (SI) to spinal motion restriction (SMR). Little research exists describing how these changes have been implemented. This study aims to describe and analyze the practice of SMR in one emergency medical services (EMS) agency over the time frame of SMR adoption.

METHODS

This was a retrospective database review of electronic patient care reports from 2009 to 2020. The effects of key practice changes (revised documentation and a collar-only treatment option) were analyzed in an interrupted time series using the rate of SI/SMR as the primary outcome. Secondary outcomes included patient age, sex, acuity, mechanism of injury, treatment provided, cervical collar size, and positioning. These were assessed for changes from year to year by Poisson regression. Associations between patient and treatment characteristics were investigated with binomial logistic regression.

RESULTS

There were 25,747 instances of SI/SMR included. Among all patients, the median age was 40 (interquartile range 24-56), 58% (14,970) were male, and 20% (5062) were high-acuity. The rate of SI/SMR declined from 31.2 to 12.7 treatments per 100 trauma calls per month. The proportion of high-acuity patients increased by 9.6% per year on average (95% CI 8.7%-10.0%). When first available, collar-only treatment was provided to 47% of patients, rising by 6.3% per year (95% CI 3.2%-9.5%) to 60% in 2020. Collar-only treatment (compared to board-and-collar) was more likely to be applied to low-acuity patients (as compared to high): odds ratio 3.01 (95% CI 2.64-3.43).

CONCLUSIONS

This study shows decreasing SI/SMR treatment and changing patient and practice characteristics. These patterns of care cannot be attributed solely to formal protocol changes. Similar patterns and their possible explanations should be investigated elsewhere.

Practice patterns after implementation of a selective spinal immobilization protocol in a regional trauma system

BACKGROUND

Universal spinal immobilization has been the standard of prehospital trauma care since the 1960s. Selective immobilization has been shown to be safe and effective for emergency medical services use, but it is unclear whether such protocols reduce unnecessary and potentially harmful immobilization practices. This study evaluated the impact of a selective spinal immobilization protocol on practice patterns in a regional trauma system.

METHODS

All encounters for traumatic injury in the Tidewater Emergency Medical Services region from 2010 to 2016 were extracted from the Virginia Pre-Hospital Information Bridge. An interrupted time series analysis was used to assess practice change after system-wide protocol implementation in 2013. Intravenous access was used as a nonequivalent outcome measure in the absence of an appropriate control group.

RESULTS

A total of 63,981 encounters were analyzed. At baseline, 16.7% of patients underwent full immobilization. The preprotocol slope was slightly positive (0.2% per month; 95% confidence interval, 0.1-0.2%). Slope and level changes after protocol implementation did not differ from those observed for intravenous access (-0.4% vs. -0.4% per month [ p = 0.4917] and -1.6% vs. -1.1% [ p = 0.1202], respectively). Cervical spinal immobilization became more common over the postimplementation period (0.1% per month; 95% confidence interval, 0.1-0.1%). Rates of immobilization for isolated penetrating trauma remained unchanged.

CONCLUSION

Implementation of a selective spinal immobilization protocol did not reduce prehospital immobilization rates in a regional trauma system. Given the entrenched nature of immobilization practices, more intensive education and training strategies are needed. Efforts should prioritize eliminating immobilization for isolated penetrating trauma given its association with increased mortality.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Cervical immobilization in trauma patients: soft collars better than rigid collars? A systematic review and meta-analysis

INTRODUCTION

Rigid cervical spine following trauma immobilization is recommended to reduce neurological disability and provide spinal stability. Soft collars have been proposed as a good alternative because of the complications related to rigid collars. The purpose of this study was to perform a systematic review on soft and rigid collars in the prehospital management of cervical trauma.

METHOD

A systematic review was performed following the PRISMA guidelines. Search terms were (immobilization) AND (collar) AND ((neck) OR (cervical)) to evaluate the range of motion (ROM) and evidence of clinical outcome for soft and rigid collars.

RESULTS

A total of 18 studies met eligibility criteria including 2 clinical studies and 16 articles investigating the range of motion (ROM). Four hundred and ninety-six patients at a mean age of 32.5 years (SD 16.8) were included. Measurements were performed in a seated position in twelve studies. Eight articles reported the ROM without a collar, 7 with a soft collar, and 15 with a rigid collar. There was no significant difference in flexion/extension, bending and rotation following immobilization with soft collars compared to no collar. Rigid collars provided significantly higher stability compared to no collar (p < 0.005) and to soft collars in flexion/extension and rotation movements (p < 0.05). The retrospective clinical studies showed no significant differences in secondary spinal cord injuries for soft collar (0.5%) and for rigid collar (1.1%). One study, comparing immobilization without a collar compared to that with a rigid collar, found a significant difference in neurologic deficiency and supraclavicular nerve lesion.

CONCLUSION

Although rigid collars provide significant higher stability to no collar and to soft collars in flexion/ extension and rotation movements, clinical studies could not confirm a difference in neurological outcome.

LEVEL OF EVIDENCE

II, Systematic Review.

Paramedic attitudes towards prehospital spinal care: a cross-sectional survey

BACKGROUND

The optimal application of spinal motion restriction (SMR) in the prehospital setting continues to be debated. Few studies have examined how changing guidelines have been received and interpreted by emergency medical services (EMS) personnel. This study surveys paramedics' attitudes, observations, and self-reported practices around the treatment of potential spine injuries in the prehospital setting.

METHODS

This was a cross-sectional survey of a North American EMS agency. After development and piloting, the final version of the survey contained four sections covering attitudes towards 1) general practice, 2) specific techniques, 3) assessment protocols, and 4) mechanisms of injury (MOI). Questions used Likert-scale, multiple-choice, yes/no, and free-text responses. Exploratory factor analysis (EFA) was used to identify latent constructs within responses, and factor scores were analyzed by ordinal logistic regression for associations with demographic characteristics (including qualification level, gender, and years of experience). MOI evaluations were assessed for inter-rater reliability (Fleiss' kappa). Inductive qualitative content analysis, following Elo & Kyngäs (2008), was used to examine free-text responses.

RESULTS

Two hundred twenty responses were received (36% of staff). Raw results indicated that respondents felt that SMR was seen as less important than in the past, that they were treating fewer patients than previously, and that they follow protocol in most situations. The EFA identified two factors: one (Judging MOIs) captured paramedics' estimation that the presented MOI could potentially cause a spine injury, and another (Treatment Value) reflected respondents' composite view of the effectiveness, importance, and applicability of SMR. Respondents with advanced life support (ALS) qualification were more likely to be skeptical of the value of SMR compared to those at the basic life support (BLS) level (OR: 2.40, 95%CI: 1.21-4.76, p = 0.01). Overall, respondents showed fair agreement in the evaluation of MOIs (k = 0.31, 95%CI: 0.09-0.49). Content analysis identified tension expressed by respondents between SMR-as-directed and SMR-as-applied.

CONCLUSION

Results of this survey show that EMS personnel are skeptical of many elements of SMR but use various strategies to balance protocol adherence with optimizing patient care. While identifying several areas for future research, these findings argue for incorporating provider feedback and judgement into future guideline revision.

A T2 Translational Science Modified Delphi Study: Spinal Motion Restriction in a Resource-Scarce Environment

INTRODUCTION

Emerging evidence is guiding changes in prehospital management of potential spinal injuries. The majority of settings related to current recommendations are in resource-rich environments (RREs), whereas there is a lack of guidance on the provision of spinal motion restriction (SMR) in resource-scarce environments (RSEs), such as: mass-casualty incidents (MCIs); low-middle income countries; complex humanitarian emergencies; conflict zones; and prolonged transport times. The application of Translational Science (TS) in the Disaster Medicine (DM) context was used to develop this study, leading to statements that can be used in the creation of evidence-based clinical guidelines (CGs).

OBJECTIVE

What is appropriate SMR in RSEs?

METHODS

The first round of this modified Delphi (mD) study was a structured focus group conducted at the World Association for Disaster and Emergency Medicine (WADEM) Congress in Brisbane Australia on May 9, 2019. The result of the focus group discussion of open-ended questions produced ten statements that were added to ten statements derived from Fischer (2018) to create the second mD round questionnaire.Academic researchers and educators, operational first responders, or first receivers of patients with suspected spinal injuries were identified to be mD experts. Experts rated their agreement with each statement on a seven-point linear numeric scale. Consensus amongst experts was defined as a standard deviation ≤1.0. Statements that were in agreement reaching consensus were included in the final report; those that were not in agreement but reached consensus were removed from further consideration. Those not reaching consensus advanced to the third mD round.For subsequent rounds, experts were shown the mean response and their own response for each of the remaining statements and asked to reconsider their rating. As above, those that did not reach consensus advanced to the next round until consensus was reached for each statement.

RESULTS

Twenty-two experts agreed to participate with 19 completing the second mD round and 16 completing the third mD round. Eleven statements reached consensus. Nine statements did not reach consensus.

CONCLUSIONS

Experts reached consensus offering 11 statements to be incorporated into the creation of SMR CGs in RSEs. The nine statements that did not reach consensus can be further studied and potentially modified to determine if these can be considered in SMR CGs in RSEs.

Prehospital Protocols Reducing Long Spinal Board Use Are Not Associated with a Change in Incidence of Spinal Cord Injury

Introduction: Many emergency medical services (EMS) agencies have de-emphasized or eliminated the use of long spinal boards (LSB) for patients with possible spinal injury. We sought to determine if implementation of spinal motion restriction (SMR) protocols, which reduce LSB use, was associated with an increase in spinal cord injury (SCI). Methods: This retrospective observational study includes EMS encounters from January 1, 2013 to December 31, 2015 submitted by SMR-adopting ground-based agencies to a state EMS database with hospital discharge data. Encounters were excluded if SMR implementation date was unknown, occurred during a 3-month run-in period, or were duplicates. Study samples include patients with traumatic injury (TI), possible spinal trauma (P-ST), and verified spinal trauma (V-ST) using hospital discharge ICD-9/10 diagnosis codes. The incidence of SCI before and after implementation of SMR was compared using Chi-squared and logistic regression. Results: From 1,005,978 linked encounters, 104,315 unique encounters with traumatic injury and known SMR implementation date were identified with 51,199 cases of P-ST and 5,178 V-ST cases. The incidence of SCI in the pre-SMR and post-SMR interval for each group was: TI, 0.20% vs. 0.22% (p = 0.390); P-ST, 0.40% vs. 0.45% (p = 0.436); and V-ST, 4.04% vs. 4.37% (p = 0.561). Age and injury severity adjusted odds ratio of SCI in the highest risk cohort of patients with V-ST was 1.097 after SMR implementation (95% CI 0.818-1.472). Conclusion: In this limited study, no change in the incidence of SCI was identified following implementation of SMR protocols. Prospective evaluation of this question is necessary to evaluate the safety of SMR protocols.

Effects of Spinal Immobilization and Spinal Motion Restriction on Head-Neck Kinematics during Ambulance Transport

Objective: To determine the influence of ambulance motion on head-neck (H-N) kinematics and to compare the effectiveness of two spinal precaution (SP) protocols: spinal immobilization (SI) and spinal motion reduction (SMR). Methods: Eighteen healthy volunteers (7 females) underwent a series of standardized ambulance transport tasks, across various speeds, under the two SP protocols in a balanced order (n = 12 drivers, n = 7 ambulances). Inertial measurement units were placed on participants' heads and sternums, with another affixed to the stretcher mattress frame. Outcome measures included H-N displacement and acceleration. Results: Ambulance accelerations varied across driving tasks (2.5-9.5 m/s²) and speeds (3.0-6.2 m/s²) and resulted in a wide range of H-N displacements (7.2-22.6 deg) and H-N accelerations (1.4-10.9 m/s²). Relative to SMR, SI resulted in reduced H-N motion during turning, accelerating, and speed bumps (1.9-10.7 deg; 0.4-2.6 m/s²), but increased H-N accelerations during abrupt starts/stops and some higher speed tasks (0.4-2.5 m/s²). Ambulance acceleration was moderately correlated to H-N acceleration (r = 0.68) and displacement (r = 0.42). Conclusion: H-N motion was somewhat coupled to ambulance acceleration and varied across a wide range, regardless of SP approach. In general, SI resulted in a modest reduction in H-N displacement and acceleration, with some exceptions. The results inform clinical decisions on SP practice during prehospital transport and demonstrate a novel approach to quantifying H-N motion in prehospital care.

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.

Removal of the Long Spine Board From Clinical Practice: A Historical Perspective

Since the early 1970s, initial management of patients with suspected spinal injuries has involved the use of a cervical collar and long spine board for full immobilization, which was thought to prevent additional injury to the cervical spine. Despite a growing body of literature demonstrating the detrimental effects and questionable efficacy of spinal immobilization, the practice continued until 2013, when the National Association of EMS Physicians issued a position statement calling for a reduction in the use of spinal immobilization and a shift to spinal-motion restriction. This article examines the literature that prompted the change in spinal-injury management and the virtual elimination of the long spine board as a tool for transport.

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 Use of Clinical Cervical Spine Clearance in Trauma Patients: A Literature Review

INTRODUCTION

Five million patients in America are placed in spinal immobilization annually, with only 1% to 2% of these patients suffering from an unstable cervical spine injury. Prehospital agencies are employing selective and limited immobilization practices, but there is concern that this practice misses cervical spine injuries and therefore possibly predisposes patients to worsening injuries.

METHODS

A systematic review was conducted that examined literature from the last 5 years that reviewed cervical spine immobilization application and/or clearance in alert trauma patients.

RESULTS

Prehospital selective immobilization protocols and bedside clinical clearance examinations are becoming more commonplace, with few missed injuries or poor outcomes. Prehospital providers can evaluate patients in the field safely to assess who needs or does not need cervical collars; similar criteria can be used in the emergency department. Harm from cervical collars is increasingly documented, with concerns that risks exceed possible benefits.

DISCUSSION

The literature suggests that alert trauma patients can be cleared from cervical spine immobilization safely through a structured algorithm in either the prehospital or ED setting. The evidence is primarily observational. Thus, many providers who fear missing cervical injuries may be reluctant to follow the recommendations despite few or no published cases of sudden deterioration from missed cervical spine injuries.

Effect of training in advanced trauma life support on the kinematics of the spine: A simulation study

More than 7.5 million people in the world are affected by spinal cord injury (SCI). In this study, we aimed to analyze the effect of training in advanced trauma life support (ATLS) on the kinematics of the spine when performing different mobilization and immobilization techniques on patients with suspected SCI. A quasi-experimental study, clinical simulation, was carried out to determine the effect of training in ATLS on 32 students enrolled in the Master's program of Emergency and Special Care Nursing. The evaluation was performed through 2 maneuvers: placing of the scoop stretcher (SS) and spinal board (SB), with an actor who simulated a clinical situation of suspected spinal injury. The misalignment of the spine was measured with the use of a Vicon 3D motion capture system, before (pre-test) and after (post-test) the training. In the overall misalignment of both maneuvers, statistically significant differences were found between the pre-test misalignment of 62.1° ± 25.9°, and the post-test misalignment of 32.3° ± 10.0°, with a difference between means of 29.7° [(95% confidence interval, 95% CI 22.8-36.6°), (P = .001)]. The results obtained for the placing of the SS showed that there was a pre-test misalignment of 65.1° ± 28.7°, and a post-test misalignment of 33.2° ± 10.1°, with a difference of means of 33.9° [(95% CI, 23.1-44.6°), (P = .001)]. During the placing of the SB, a pre-test misalignment of 59.0° ± 28.7° and a post-test misalignment of 33.4° ± 10.0° were obtained, as well as a difference of means of 25.6° [(95% CI 16.6-34.6°), (P = .001)]. The main conclusion of this study is that training in ATLS decreases the misalignment provoked during the utilization of the SS and SB, regardless of the device used.

Quantifying the Risk of Spinal Injury in Motor Vehicle Collisions According to Ambulatory Status: A Prospective Analytical Study

BACKGROUND

The association between ambulation at the scene of a motor vehicle collision (MVC) and spinal injury has never been quantified.

OBJECTIVE

To evaluate the association between ambulation and spinal injury in patients involved in a MVC.

METHODS

Prospective analytical-observational cohort study. Inclusion: patients sustaining traumatic injury in a MVC. Exclusion: < 18 years old, pregnancy.

PRIMARY OUTCOME

spinal injury defined as injury to the cervical, thoracic, or lumbar spinal cord, bones, or ligaments. Secondary outcome: Injury resulting in neurological deficit, need for surgery, or death. A generalized linear model was used to evaluate the association between outcome and predictor variables. Risk ratios [RR] were reported with a point estimate and 95% confidence interval (CI). A two-tailed alpha of < 0.05 was the threshold for statistical significance.

RESULTS

There were 704 patients analyzed. Nonambulatory patients were 2.29 times more likely to sustain a spinal injury, compared to ambulatory patients (RR 2.29, 95% CI 1.34-3.91). Patients ≥ 65 years of age were 3.27 times more likely to sustain a spinal injury (RR 3.27, 95% CI 1.66-6.45). Patients with a Glasgow Coma Scale score ≤ 8 were 4.93 times more likely to sustain a spinal injury (RR 4.93, 95% CI 1.86-13.10).

CONCLUSION

In this prospective analytical-observational study evaluating the association between ambulatory status and spinal injury in patients involved in MVCs, we observed that those patients who were nonambulatory were more than two times as likely to have a spinal injury compared to those patients who were ambulatory at the scene.

Outcomes and characteristics of non-immobilised, spine-injured trauma patients: a systematic review of prehospital selective immobilisation protocols

OBJECTIVES

This review assesses prehospital selective immobilisation protocols across a range of outcomes, including neurological deterioration and characteristics of injured, non-immobilised patients.

METHODS

Six electronic reference databases and eight grey literature sources were systematically searched. We included studies that enrolled acute trauma patients in the prehospital setting who were assessed for spine injury according to predefined clinical criteria and either immobilised or not. Data items included instances of neurological deterioration among patients with spine injuries, as well as available characteristics of those who were injured and not immobilised. Available data and study heterogeneity prevented meta-analyses. Bias was assessed for both individual studies and across studies by outcome.

RESULTS

604 unique articles were retrieved, of which 7 met inclusion criteria. There was moderate or high risk of bias across studies in all outcomes. Of 76 patients with spine injuries who were not immobilised, 72 had no neurological deficit that appeared after emergency medical services contact, and the remaining four were not followed. Within this group, there appears to be a trend towards elderly patients who suffered a thoracic or lumbar injury from a low-risk mechanism of injury. Among studies that report both the results of the protocol assessment and immobilisation status, there is variable correspondence between the two.

CONCLUSIONS

Data limitations and study biases suggest caution when interpreting and applying the results of this review. Its findings are consistent with the conclusions of individual studies. The characteristics of injured, non-immobilised patients point to areas of future research to investigate apparent trends.

Effect of spinal immobilisation devices on radiation exposure in conventional radiography and computed tomography

Trauma patients at risk for, or suspected of, spinal injury are frequently transported to hospital using full spinal immobilisation. At the emergency department, immobilisation is often maintained until radiological work-up is completed. In this study, we examined how these devices influence radiation exposure and noise, as a proxy for objective image quality. Conventional radiographs (CR) and computer tomography (CT) scans were made using a phantom immobilised on two types of spineboard and a vacuum mattress and using two types of headblocks. Images were compared for radiation transmission and quantitative image noise. In CR, up to 23 % and, in CT, up to 11 % of radiation were blocked by the devices. Without compensation for the decreased transmission, noise increased by up to 16 % in CT, depending on the device used. Removing the headblocks led to a statistically significant improvement in transmission with automatic exposure control (AEC) enabled. Physicians should make an informed decision whether the increased radiation exposure outweighs the risk of missing a clinically significant injury by not making a CR or CT scan. Manufacturers of immobilisation devices should take radiological properties of their devices into account in the development and production process.

Prehospital Spinal Immobilization: Effect of Effort on Kinematics of Voluntary Head-neck Motion Assessed using Accelerometry

INTRODUCTION

Standards for immobilizing potentially spine-injured patients in the prehospital environment are evolving. Current guidelines call for more research into treatment practices. Available research into spinal immobilization (SI) reveals a number of limitations.

PROBLEM

There are currently few techniques for measuring head and neck motion that address identified limitations and can be adapted to clinically relevant scenarios. This study investigates one possible method.

METHODS

Study participants were fitted with miniaturized accelerometers to record head motion. Participants were exposed to three levels of restraint: none, cervical-collar only, and full immobilization. In each condition, participants were instructed to move in single planes, with multiple iterations at each of four levels of effort. Participants were also instructed to move continuously in multiple planes, with iterations at each of three levels of simulated patient movement. Peak and average displacement and acceleration were calculated for each immobilization condition and level of effort. Comparisons were made with video-based measurement. Participant characteristics also were tracked.

RESULTS

Acceleration and displacement of the head increased with effort and decreased with more restraint. In some conditions, participants generated measurable acceleration with minimal displacement. Continuous, multi-dimensional motions produced greater displacement and acceleration than single-plane motions under similar conditions.

CONCLUSION

Study results suggest a number of findings: acceleration complements displacement as a measure of motion in potentially spine-injured patients; participant effort has an effect on outcome measures; and continuous, multi-dimensional motion can produce results that differ from single-plane motions. Miniaturized accelerometers are a promising technology for future research to investigate these findings in realistic, clinically relevant scenarios.

Confirmation of suboptimal protocols in spinal immobilisation?

Background

Spinal immobilisation during extrication of patients in road traffic collisions is routinely used despite the lack of evidence for this practice. In a previous proof of concept study (n=1), we recorded up to four times more cervical spine movement during extrication using conventional techniques than self-controlled extrication.

Objective

The objective of this study was to establish, using biomechanical analysis which technique provides the minimal deviation of the cervical spine from the neutral in-line position during extrication from a vehicle in a larger sample of variable age, height and mass.

Methods

A crew of two paramedics and four fire-fighters extricated 16 immobilised participants from a vehicle using six techniques for each participant. Participants were marked with biomechanical sensors and relative movement between the sensors was captured via high-speed infrared motion analysis cameras. A three-dimensional mathematical model was developed and a repeated-measures analysis of variance was used to compare movement across extrication techniques.

Results

Controlled self-extrication without a collar resulted in a mean movement of 13.33° from the neutral in-line position of the cervical spine compared to a mean movement of 18.84° during one of the equipment-aided extrications. Two equipment-aided techniques had significantly higher movement (p<0.05) than other techniques. Both height (p=0.003) and mass (p=0.02) of the participants were significant independent predictors of movement.

Conclusions

These data support the findings of the proof of concept study, for haemodynamically stable patients controlled self-extrication causes less movement of the cervical spine than extrications performed using traditional prehospital rescue equipment.