How Does Rescuer Fitness Affect the Quality of Prolonged Cardiopulmonary Resuscitation?

Objective: High quality cardiopulmonary resuscitation (CPR) is crucial for patients experiencing cardiac arrest. CPR quality declines within the first few minutes of CPR performance. Being more fit is associated with higher CPR quality, yet the fitness parameters needed remain uncertain. It is also unknown how CPR quality is affected during a protocol of realistic CPR when rescuers switch compressors every two minutes, as recommended by the American Heart Association (AHA), and extended duration, as might be encountered with an out-of-hospital cardiac arrest. The purpose of the present study is to determine the extent to which different measures of physical fitness predict high quality CPR performance when rescuers follow current CPR guidelines. Methods: Subjects underwent a fitness assessment evaluating lower back muscular endurance, abdominal muscular endurance, upper body muscular strength, and upper body anaerobic power. At least 48 hours later, subjects returned to the laboratory for CPR testing. CPR quality was determined by compression rate (>100/minute), compression depth (>2 inches, or 50 mm), and adequate (full) chest recoil between compressions, based on American Heart Association guidelines. A CPR Quality Score, designed to represent cardiac output, was calculated as the product of compression rate and depth. Results: Thirty-three of 42 subjects were able to achieve a CPR Quality Score greater than 5000, the minimum needed to meet AHA recommendations. Higher anaerobic power and bench press scores were predictive of both high CPR Quality Scores (R2=0.47) and compression depth (R2=0.47). Sex (female) was predictive of better chest compression recoil percentages (R2=0.15). Conclusion: Most rescuers can maintain high quality CPR if given two minute breaks between cycles. Rescuers with high anaerobic fitness and muscular strength may be able to provide higher quality CPR.

EMS Curriculum Should Educate Beyond a Technical Scope of Practice: Position Statement and Resource Document.

Position Statement and Resource document approved by the NAEMSP Board of Directors on April 27, 2021.

Prehospital amputation: An experimental comparison of techniques.

OBJECTIVE: Prehospital limb amputation is a rare but potentially life-saving intervention. When patients cannot be extricated due to limb entrapment or have hemodynamic compromise that precludes a prolonged extrication, they may benefit from an emergent prehospital amputation. The objective was to experimentally compare three prehospital amputation techniques on porcine legs. METHODS: The three techniques studied were a scalpel with a Gigli saw, a hacksaw, and a reciprocating saw. For the first technique, a scalpel was used to make a circumferential incision in the soft tissue and a Gigli wire saw to cut through the bone. The second and third techniques only used a saw and did not require soft tissue incision with a scalpel. Three providers including an emergency medicine physician, a paramedic, and a medical student performed three amputations of each technique, resulting in twenty-seven total amputations. The primary outcome was amputation time. Secondary outcomes were rate of instrument malfunction and cleanliness of cut. RESULTS: The primary outcome of amputation time was different between techniques. The Gigli saw technique took 32.86 ± 16.53 s (mean ± SD), hacksaw technique 6.28 ± 0.76 s, and reciprocating saw technique 2.84 ± 0.40 s. There were no differences in amputation time between participants for a given amputation technique. The Gigli saw technique had an instrument malfunction on 3/9 trials which was distinct from the other techniques. Differences in cleanliness of cut were nonsignificant. CONCLUSIONS: Prehospital limb amputation with a hacksaw or reciprocating saw may result in faster completion of the time-sensitive procedure with fewer instrument malfunctions.

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.

Helicopter transportation in the era of thrombectomy: The next frontier for acute stroke treatment and research.

PURPOSE: Many patients suffer a stroke at a significant distance from a specialized center capable of delivering endovascular therapy. As a result, they require rapid transport by helicopter emergency medical services, sometimes while receiving a recombinant tissue plasminogen activator infusion (drip and ship). Despite its critical role in the new era of reperfusion, helicopter emergency medical services remains a poorly evaluated aspect of stroke care. METHOD: Comprehensive narrative review of all published articles of helicopter emergency medical services related to acute stroke care in the inter-hospital and pre-hospital settings, including technical aspects and physical environment implications. FINDINGS: Helicopter emergency medical services transports are conducted during a critical early time period when specific interventions and ancillary care practices may have a significant influence on outcomes. We have limited knowledge of the potential impact of the unusual physical factors generated by the helicopter on the ischemic brain, which affects our ability to establish rational guidelines for ancillary care and the delivery of specific interventions. DISCUSSION: Unlike the pre-hospital and hospital settings where stroke interventions are delivered, the inter-hospital helicopter emergency medical services transfer setting remains a "black box" for acute stroke care and research. This gap is particularly relevant for many patients living in rural areas, or in congested urban areas, that depend on helicopter emergency medical services for rapid access to a tertiary stroke center. CONCLUSION: Addressing the helicopter emergency medical services stroke gap in clinical trials and acute care delivery would homogenize capabilities through all care settings, thus minimizing potential disparities in research access and outcomes based on geographical location.