Evaluating time until ligation in a novel tourniquet - A crossover randomized-controlled trial.

INTRODUCTION AND AIM: Severe external hemorrhage is a significant reason for morbidity and mortality in adults; thus, the swift and correct application of a tourniquet by laypersons can be lifesaving. We conducted this randomized-controlled cross-over study to investigate the use of a novel tourniquet. METHODS: Participants were recruited at the Heidelberg University Hospital. Eligible participants were ≥ 18 years old with a medical background but without prior experience in applying a tourniquet. Participants were 1:1 randomized to the intervention group (PAX tourniquet) or the control group (SAM or CAT tourniquet). In the control group, participants underwent another randomization to either the SAM or CAT tourniquet without a predefined allocation ratio. Hyperspectral measurements were undertaken (i) before ligation, (ii) 30 s after ligation, and (iii) 30 s after the reopening of the tourniquet. The primary outcome was time until ligation before crossover between the respective groups. The analysis of secondary endpoints included all attempts to assess a possible learning effect, intraoperator variability, and hyperspectral measurements. Participants were crossed to the other study group after a brief wash-out phase. RESULTS: In total, 50 participants were recruited, resulting in 100 attempts. A success rate of 98% was observed across the study population. Time until ligation was 49 s and 56 s (p = 0.572) in the intervention and control group, respectively. However, there was a significant difference between the PAX and SAM (54 vs 75 s; p = 0.037) and the SAM and CAT tourniquet (75 vs. 47 s; p = 0.015). Further, we observed a significant learning effect in participants allocated to the control group first, with a median reduction of 9 s in the time until ligation. Hyperspectral measurements showed a significant decrease in perfusion and tissue oxygenation after ligation. Further, a significant increase in perfusion and tissue oxygenation was found after reopening the tourniquet compared to the baseline measurement. CONCLUSION: The novel PAX tourniquet can be applied quickly and effectively by medical personnel without prior experience in applying a tourniquet.

[Extracorporeal Life Support in Critical Care Medicine]. / Extrakorporaler Life Support in der Intensivmedizin.

Veno-arterial extracorporeal life support (ECLS) may be indicated in patients with refractory heart failure. The list of conditions in which ECLS is successfully used is growing and includes cardiogenic shock following myocardial infarction, refractory cardiac arrest, septic shock with low cardiac output and severe intoxication. Femoral ECLS is the most common and often preferred ECLS-configuration in the emergency setting. Although femoral access is usually quick and easy to establish, it is also associated with specific adverse haemodynamic effects due to the direction of blood flow and access-site complications are inherent. Femoral ECLS provides adequate oxygen delivery and compensates for impaired cardiac output. However, retrograde blood flow into the aorta increases left ventricular afterload and may worsen left ventricular stroke work. Therefore, femoral ECLS is not equivalent to left ventricular unloading. Daily haemodynamic assessments are crucial and should include echocardiography and laboratory tests determining tissue oxygenation. Common complications include the harlequin-phenomenon, lower limb ischaemia or cerebral events and cannula site or intracranial bleeding. Despite a high incidence of complications and high mortality, ECLS is associated with survival benefits and better neurological outcomes in selected patient groups.

[Diagnostics and Invasive Techniques in the Treatment of Chest Trauma]. / Diagnostik und invasive Maßnahmen beim Thoraxtrauma.

Chest Trauma is a complex injury pattern whose diagnostics and therapy demand everything from an emergency response team. Chest trauma subsumes thoracic injuries in all facets from the bounce mark of a seat belt to fatal rollover trauma with contusion or disruption of organs located in the thorax. Possible causes comprise blunt or penetrating trauma, as well as decelerations, chemical and thermal damage. Sonographic assessment according to a protocol plays a major role in diagnosis of underlying conditions and treatment indications. Therapeutic management may include invasive emergency techniques: Decompression of a tension pneumothorax is a fundamental life-saving intervention. Pericardiocentesis seldomly is necessary or possible in order to drain a cardiac tamponade. In case of traumatic cardiac arrest and under defined circumstances, resuscitative thoracotomy may be indicated. The out-of-hospital management may require transfusion of blood components. As with all procedures, which are performed seldomly but under emergency conditions, invasive techniques require clear communication, precise structured working procedures and especially continuous training, team briefing, and debriefing.

Spinal movement and dural sac compression during airway management in a cadaveric model with atlanto-occipital instability.

PURPOSE: To analyze the compression of the dural sac and the cervical spinal movement during performing different airway interventions in case of atlanto-occipital dislocation. METHODS: In six fresh cadavers, atlanto-occipital dislocation was performed by distracting the opened atlanto-occipital joint capsule and sectioning the tectorial membrane. Airway management was done using three airway devices (direct laryngoscopy, video laryngoscopy, and insertion of a laryngeal tube). The change of dural sac's width and intervertebral angulation in stable and unstable atlanto-occipital conditions were recorded by video fluoroscopy with myelography. Three-dimensional overall movement of cervical spine was measured in a wireless human motion track system. RESULTS: Compared with a mean dural sac compression of - 0.5 mm (- 0.7 to - 0.3 mm) in stable condition, direct laryngoscopy caused an increased dural sac compression of - 1.6 mm (- 1.9 to - 0.6 mm, p = 0.028) in the unstable atlanto-occipital condition. No increased compression on dural sac was found using video laryngoscopy or the laryngeal tube. Moreover, direct laryngoscopy caused greater overall extension and rotation of cervical spine than laryngeal tube insertion in both stable and unstable conditions. Among three procedures, the insertion of a laryngeal tube took the shortest time. CONCLUSION: In case of atlanto-occipital dislocation, intubation using direct laryngoscopy exacerbates dural sac compression and may cause damage to the spinal cord.

[Clamshell thoracotomy after thoracic knife wounds]. / Clamshell-Thorakotomie nach thorakalen Messerstichen.

Resuscitation in the event of traumatic cardiac arrest was for a long time considered to be a less than promising technique to employ; however, current data indicate that the prospects of success need not be any poorer than for resuscitation due to cardiac distress. The targeted and rapid remedying of reversible causes can re-establish the circulatory function and the European Resuscitation Council (ERC) algorithm for traumatic cardiac arrest is a helpful guide in this respect. This case report illustrates the resolute implementation of this algorithm in the prehospital environment in the case of an attempted suicide by a thoracic knife wound.

Analysis of spine motion during prehospital extrication procedures in motorsport.

PURPOSE: The appropriate extrication techniques for trauma patients after car accidents remain a topic of controversy. Various techniques for immobilizing the cervical spine during prehospital extrication have been investigated. METHODS: This explorative study compared the amount of spinal motion during five different extrication procedures from a racecar and a rallycar performed by two teams: a professional motorsport extrication team and a team of professional emergency medical technicians (EMTs). Two different microelectromechanical systems were used to measure spinal motion, and a motionscore was calculated to compare the amount of remaining spinal motion. A high motionscore indicates high remaining motion and a low motionscore indicates low remaining motion. RESULTS: The use of an extricable seat results in a mean overall motion score of 1617 [95% CI 308-2926]. Emergency extrication without equipment resulted in the lowest overall motionscore 1448 [95% CI 1070-1826]. In case of urgent extrication the Extrication team attained a motionscore of 2118 [95% CI 517-3718] and the EMT team a motionscore of 2932 [95% CI 1427-4435]. When performing the procedure with the aid of a rescue boa, the EMT team achieved an overall mean motionscore in the same range 2725 [95% CI 568-4881] with boa vs. 2932 [95% CI 1427-4435] without boa. When mean scores of individual spinal segments were analyzed, we found that the EMT team did especially worse in immobilizing the cervical spine 198 vs. 758. CONCLUSIONS: Regular training of extrication procedures has paid off considerably in reducing spinal movement during extrication from a racecar. If an extricable seat is available, extrication should be performed using it. However, if emergency extrication is necessary, an additional manual cervical spine immobilization should be conducted using the Rautek maneuver to sufficiently reduce cervical spine movement.

Non-Invasive Ventilation as a Therapy Option for Acute Exacerbations of Chronic Obstructive Pulmonary Disease and Acute Cardiopulmonary Oedema in Emergency Medical Services.

In this observational prospective multicenter study conducted between October 2016 and October 2018, we tested the hypothesis that the use of prehospital non-invasive ventilation (phNIV) to treat patients with acute respiratory insufficiency (ARI) caused by severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and acute cardiopulmonary oedema (ACPE) is effective, time-efficient and safe. The data were collected at four different physician response units and three admitting hospitals in a German EMS system. Patients with respiratory failure due to acute exacerbation of chronic obstructive pulmonary disease and acute cardiopulmonary oedema were enrolled. A total of 545 patients were eligible for the final analysis. Patients were treated with oxygen supplementation, non-invasive ventilation or invasive mechanical ventilation. The primary outcomes were defined as changes in the clinical parameters and the in-hospital course. The secondary outcomes included time efficiency, peri-interventional complications, treatment failure rate, and side-effects. Oxygenation under phNIV improved equally to endotracheal intubation (ETI), and more effectively in comparison to standard oxygen therapy (SOT) (paO2 SOT vs. non-invasive ventilation (NIV) vs. ETI: 82 mmHg vs. 125 mmHg vs. 135 mmHg, p-value SOT vs. NIV < 0.0001). In a matched subgroup analysis phNIV was accompanied by a reduced time of mechanical ventilation (phNIV: 1.8 d vs. ETI: 4.2 d) and a shortened length of stay at the intensive care unit (3.4 d vs. 5.8 d). The data support the hypothesis that the treatment of severe AECOPD/ACPE-induced ARI using prehospital NIV is effective, time efficient and safe. Compared to ETI, a matched comparison supports the hypothesis that prehospital implementation of NIV may provide benefits for an in-hospital course.

Cervical Spine Immobilization in Patients With a Geriatric Facial Structure: The Influence of a Geriatric Mandible Structure on the Immobilization Quality Using a Cervical Collar.

INTRODUCTION: Demographic changes have resulted in an increase in injuries among geriatric patients. For these patients, a rigid cervical collar is crucial for immobilizing the cervical spine. However, evidence suggests that patients with a geriatric facial structure require a different means of immobilization than patients with an adult facial structure. This study aimed to analyze the remaining motion of the immobilized cervical spine based on facial structure. MATERIALS AND METHODS: This study was performed on 8 fresh human cadavers. Facial structure was evaluated via ascertaining the mandibular angle by computer tomography. A mandibular angle below 130°, belongs to the adult facial structure group (n = 4) and a mandibular angle above 130°, belongs to the geriatric facial structure group (n = 4). The flexion and lateral bending of the immobilized cervical spine were analyzed in both groups using a wireless motion tracker system. RESULTS: A flexion of up to 19.0° was measured in the adult facial structure group. The mean flexion in the adult vs. geriatric facial structure groups were 14.5° vs. 6.5° (ranges: 9.0-19.0 vs. 5.0-7.0°), respectively. Thus, cervical spine motion was (p = 0.0286) significantly more reduced in the adult facial structure group. No (p = 0.0571) significant difference was oberserved in the mean lateral bending of the adult facial structure group (14.5°) compared to the geriatric facial structure group (7.5°). CONCLUSION: Emergency medical service personnel should therefore follow current guidelines and recommendations and perform cervical spine immobilization with a cervical collar, including in patients with a geriatric facial structure.

Analysis of remaining motion using one innovative upper airway opening cervical collar and two traditional cervical collars.

The aim of this study was to compare the remaining motion of an immobilized cervical spine using an innovative cervical collar as well as two traditional cervical collars. The study was performed on eight fresh human cadavers. The cervical spine was immobilized with one innovative (Lubo Airway Collar) and two traditional cervical collars (Stifneck and Perfit ACE). The flexion and lateral bending of the cervical spine were measured using a wireless motion tracker (Xsens). With the Weinman Lubo Airway Collar attached, the mean remaining flexion was 20.0 ± 9.0°. The mean remaining flexion was lowest with the Laerdal Stifneck (13.1 ± 6.6°) or Ambu Perfit ACE (10.8 ± 5.8°) applied. Compared to that of the innovative Weinmann Lubo Airway Collar, the remaining cervical spine flexion was significantly decreased with the Ambu Perfit ACE. There was no significant difference in lateral bending between the three examined collars. The most effective immobilization of the cervical spine was achieved when traditional cervical collars were implemented. However, all tested cervical collars showed remaining motion of the cervical spine. Thus, alternative immobilization techniques should be considered.

Evaluation of external stabilization of type II odontoid fractures in geriatric patients-An experimental study on a newly developed cadaveric trauma model.

BACKGROUND: Along with the growing geriatric population, the number of odontoid fractures is steadily increasing. However, the effectiveness of immobilizing geriatric odontoid fractures using a cervical collar has been questioned. The aim of the present study is to analyze the physiological and pathological motion in odontoid fractures and to assess limitation of motion in the cervical spine when applying a cervical collar. METHODS: Motion analysis was performed with wireless motion tracker on unfixed geriatric human cadavers. First, a new geriatric type II odontoid fracture model was developed. In this model, the type II odontoid fracture is operated via a transoral approach. The physiological and pathological flexion and lateral bending of the cervical spine resulting from this procedure was measured. The resulting motion after external stabilization using a cervical collar was analyzed. RESULTS: The new geriatric type II odontoid fracture model was successfully established using seven unfixed human cadavers. The pathological flexion of the cervical spine was significantly increased compared to the physiological flexion (p = 0.027). Furthermore, the flexion was significantly reduced when a cervical collar was applied. In case of flexion the mean remaining motion was significantly reduced (p = 0.0017) from 41° to 14°. For lateral bending the mean remaining motion was significantly reduced (p = 0.0137) from 48° to 18°. CONCLUSIONS: In case of type II odontoid fracture, flexion and lateral bending of the cervical spine are increased due to spinal instability. Thus, if an odontoid fracture is suspected in geriatric patients, the application of a cervical collar should always be considered since external stabilization can significantly reduce flexion and lateral bending.

Motion and dural sac compression in the upper cervical spine during the application of a cervical collar in case of unstable craniocervical junction-A study in two new cadaveric trauma models.

BACKGROUND: Unstable conditions of the craniocervical junction such as atlanto-occipital dislocation (AOD) or atlanto-axial instability (AAI) are severe injuries with a high risk of tetraplegia or death. Immobilization by a cervical collar to protect the patient from secondary damage is a standard procedure in trauma patients. If the application of a cervical collar to a patient with an unstable craniocervical condition may cause segmental motion and secondary injury to the spinal cord is unknown. The aim of the current study is (i) to analyze compression on the dural sac and (ii) to determine relative motion of the cervical spine during the procedure of applying a cervical collar in case of ligamentous unstable craniocervical junction. METHODS AND FINDINGS: Ligamentous AOD as well as AOD combined with ligamentous AAI was simulated in two newly developed cadaveric trauma models. Compression of the dural sac and segmental angulation in the upper cervical spine were measured on video fluoroscopy after myelography during the application of a cervical collar. Furthermore, overall three-dimensional motion of the cervical spine was measured by a motion tracking system. In six cadavers each, the two new trauma models on AOD and AOD combined with AAI could be implemented. Mean dural sac compression was significantly increased to -1.1 mm (-1.3 to -0.7 mm) in case of AOD and -1.2 mm (-1.6 to -0.6 mm) in the combined model of AOD and AAI. Furthermore, there is a significant increased angulation at the C0/C1 level in the AOD model. Immense three-dimensional movement up to 22.9° of cervical spine flexion was documented during the procedure. CONCLUSION: The current study pointed out that applying a cervical collar in general will cause immense three-dimensional movement. In case of unstable craniocervical junction, this leads to a dural sac compression and thus to possible damage to the spinal cord.