Anesthesia in prehospital emergencies and in the emergency department

[Prehospital emergency anesthesia in adults : Current recommendations for performing prehospital emergency anesthesia based on the recommendations for prehospital emergency anesthesia in adults]

The frequency of prehospital emergency anesthesia in Germany is around 2-3% of all emergency medical missions. The Association of the Scientific Medical Societies of Germany (AWMF) has published guidelines for the implementation of a prehospital emergency anesthesia. The purpose of this article is to highlight important aspects from these guidelines and to present the implementation and special features for specific patient groups. A case study is intended to illustrate that the preclinical setting can provide various facets that make a certain amount of experience and expertise indispensable. The article emphasizes that clear standard situations are not always present and that there are some challenges in the preclinical setting. Therefore, mastering the content of prehospital emergency anesthesia and the manual skills of induction of anesthesia are essential and obligatory for the emergency team.

Inducción Anestésica: Propofol, Ketamina o Ketofol ¿Cuándo utilizarlos?

Introducción: La anestesia general se subdivide en diferentes etapas donde una de las más importantes es la etapa de la inducción anestésica y los fármacos que se utilizan en ella, siendo el Propofol y la Ketamina los más nombrados Objetivo: Realizar una revisión de las propiedades farmacocinéticas y farmacodinámicas de estos dos medicamentos, para la toma de decisiones sobre en qué situaciones debería usarse cada uno de ellos o de forma concomitante Materiales y métodos: Se realizaron 4 búsquedas separadas en la base de datos de PUBMED, obteniendo un total de 27 bibliografías utilizadas para la revisión. Resultados: El propofol es un agente hipnótico útil para procedimientos cortos, en pacientes estables hemodinámicamente. La ketamina tiene un perfil farmacodinámico ideal para pacientes con inestabilidad hemodinámica. El ketofol es una alternativa que logra adecuado sinergismo permitiendo mantener los beneficios de cada uno de estos medicamentos y disminuyendo la probabilidad de efectos adversos. Conclusión: Dependiendo de la cirugía que se vaya a realizar y de la estabilidad hemodinámica de cada paciente se puede preferir un medicamento sobre otro.

Incidence of hyperoxia in trauma patients receiving pre-hospital emergency anaesthesia: results of a 5-year retrospective analysis

Background

Previous studies have demonstrated an association between hyperoxia and increased mortality in various patient groups. Critically unwell and injured patients are routinely given high concentration oxygen in the pre-hospital phase of care. We aim to investigate the incidence of hyperoxia in major trauma patients receiving pre-hospital emergency anesthesia (PHEA) in the pre-hospital setting and determine factors that may help guide clinicians with pre-hospital oxygen administration in these patients.

Methods

A retrospective cohort study was performed of all patients who received PHEA by a single helicopter emergency medical service (HEMS) between 1 October 2014 and 1 May 2019 and who were subsequently transferred to one major trauma centre (MTC). Patient and treatment factors were collected from the electronic patient records of the HEMS service and the MTC. Hyperoxia was defined as a PaO₂ > 16 kPA on the first arterial blood gas analysis upon arrival in the MTC.

Results

On arrival in the MTC, the majority of the patients (90/147, 61.2%) had severe hyperoxia, whereas 30 patients (20.4%) had mild hyperoxia and 26 patients (19.7%) had normoxia. Only 1 patient (0.7%) had hypoxia. The median PaO₂ on the first arterial blood gas analysis (ABGA) after HEMS handover was 36.7 [IQR 18.5–52.2] kPa, with a range of 7.0–86.0 kPa. SpO₂ pulse oximetry readings before handover were independently associated with the presence of hyperoxia. An SpO₂ ≥ 97% was associated with a significantly increased odds of hyperoxia (OR 3.99 [1.58–10.08]), and had a sensitivity of 86.7% [79.1–92.4], a specificity of 37.9% [20.7–57.8], a positive predictive value of 84.5% [70.2–87.9] and a negative predictive value of 42.3% [27.4–58.7] for the presence of hyperoxemia.

Conclusion

Trauma patients who have undergone PHEA often have profound hyperoxemia upon arrival at hospital. In the pre-hospital setting, where arterial blood gas analysis is not readily available a titrated approach to oxygen therapy should be considered to reduce the incidence of potentially harmful tissue hyperoxia.

Effects of continuous ketamine infusion on hemodynamics and mortality in critically ill children

We investigated the hemodynamic and mortality effects of continuous ketamine infusion in critically ill pediatric patients. We conducted a retrospective cohort study in a tertiary pediatric intensive care unit (PICU). Patients who used continuous sedative from 2015 to 2017 for 24 hours or more were included. We compared blood pressure, heart and respiratory rates, vasogenic medications, and sedation and pain scores for 12 hours before and after initiation of continuous ketamine. The mortality rates for continuous ketamine and Non-ketamine groups were compared by multivariate logistic regression. A total of 240 patients used continuous sedation, and 82 used continuous ketamine. The median infusion rate of ketamine was 8.1 mcg/kg/min, and the median duration was 6 days. Heart rates (138 vs. 135 beat/minute, P = .033) and respiratory rates (31 vs. 25 respiration/minute, P = .001) decreased, but blood pressure (99.9 vs. 101.1 mm Hg, P = .124) and vasogenic medications did not change after ketamine infusion. Continuous ketamine was not a significant risk factor for mortality (hazard ratio 1.352, confidence interval 0.458–3.996). Continous ketamine could be used in PICU without hemodynamic instability. Further studies in randomized controlled design about the effects of continuous ketamine infusion on hemodynamic changes, sedation, and mortality are required.

Management of an Entrapped Patient with a Field Amputation

BACKGROUND

Emergency surgical amputations are rare and resource-intensive lifesaving interventions. Most emergency medical services (EMS) lack a formal protocol to manage these high-risk but low-occurrence events. There has been limited attention in the EMS community to address this issue. Without a literature-based approach, the EMS community has been offered little guidance on managing surgical field amputations.

CASE REPORT

A 38-year-old man was terminally entrapped below the waist in an industrial auger. As a last resort, the decision to initiate a field amputation was made. We outline an adaptive strategy to address the circumstances surrounding this entrapment scenario. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: A carefully preplanned protocol may lead to increased overall survivability for entrapped patients requiring emergent field amputation. Based on the lessons learned from the outcome of this case, previous cases, and a literature review, we have devised a simplified planning tool in the form of a "LIMB" mnemonic to aid EMS services in developing their own traumatic amputation protocol (TAP). "LIMB" is an acronym for: Lists of resources and equipment, Initiate TAP checklist, Manage the extrication, and Bring the patient in. The LIMB mnemonic may also be used as a checklist to assist EMS personnel in performing a field amputation. We offer rescuers a starting point to develop their own TAP capable of being executed in their own rescue environment.

Ketamine use in current clinical practice

After nearly half a century on the market, ketamine still occupies a unique corner in the medical armamentarium of anesthesiologists or clinicians treating pain. Over the last two decades, much research has been conducted highlighting the drug's mechanisms of action, specifically those of its enantiomers. Nowadays, ketamine is also being utilized for pediatric pain control in emergency department, with its anti-hyperalgesic and anti-inflammatory effects being revealed in acute and chronic pain management. Recently, new insights have been gained on ketamine's potential anti-depressive and antisuicidal effects. This article provides an overview of the drug's pharmacokinetics and pharmacodynamics while also discussing the potential benefits and risks of ketamine administration in various clinical settings.

[Accidental hypothermia]

Uncertainty exists on how to treat patients suffering from accidental hypothermia and on the optimal transport decisions. The aim of this review is to provide an updated evidence-based reference for the pre-hospital and in-hospital management of patients with accidental hypothermia and for the transport decisions required to facilitate treatment. Advances in the efficiency and availability of rewarming techniques have improved the prognosis for patients presenting with hypothermia. For hypothermic patients with a core body temperature ≥ 28 °C without cardiac instability there is increasing evidence to support the use of active external and minimally invasive rewarming techniques (e.g. chemical, electrical or forced air heating packs, blankets and warm parenteral fluids). Hypothermic patients with cardiac instability (i.e. systolic blood pressure < 90 mmHg, ventricular arrhythmia and core body temperature < 28 °C) should be rewarmed with active external and minimally invasive rewarming techniques in a hospital which also has circulation substituting venous-arterial extracorporeal membrane oxygenation (VA-ECMO) and cardiopulmonary bypass (CBP) facilities. In cardiac arrest patients VA-ECMO may be a better treatment option than CBP and survival rates of 100 % can be achieved compared to ~ 10 % with traditional methods (e.g. body cavity lavage). Early transport to a hospital appropriately equipped for rewarming has the potential to decrease complication rates and improve survival.

Ketamine: use in anesthesia

The role of ketamine anesthesia in the prehospital, emergency department and operating theater settings is not well defined. A nonsystematic review of ketamine was performed by authors from Australia, Europe, and North America. Results were discussed among authors and the final manuscript accepted. Ketamine is a useful agent for induction of anesthesia, procedural sedation, and analgesia. Its properties are appealing in many awkward clinical scenarios. Practitioners need to be cognizant of its side effects and limitations.

[Supraglottic airway devices in emergency medicine : impact of gastric drainage]

This case report describes a life-saving use of a supraglottic airway device (LT-D™-Larynxtubus, VBM Medizintechnik, Sulz, Germany) in an out-of-hospital emergency patient suffering from severe traumatic brain injury. Mechanical ventilation with the laryngeal tube was complicated by repeated airway obstructions and pronounced gastric distension with air as a consequence of oropharyngeal leakage. In this situation pulmonary ventilation of the patient was compromised so that emergency endotracheal intubation became necessary in the resuscitation area with vital indications. In this context the status of supraglottic airway devices in emergency medicine is discussed as well as the reasons for the gastric distension. Besides the immediate drastic consequences of gastric distension with respect to pulmonary ventilation, potential deleterious non-pulmonary consequences of this complication are highlighted. The clinical relevance of the described complications as well as the associated possibility of an optimized position control necessitate the recommendation only to use second generation supraglottic airway devices with integrated gastric access in (out-of-hospital) emergency medicine.

[Comments on the 2010 guidelines on cardiopulmonary resuscitation of the European Resuscitation Council]

ADULTS

Administer chest compressions (minimum 100/min, minimum 5 cm depth) at a ratio of 30:2 with ventilation (tidal volume 500-600 ml, inspiration time 1 s, F(I)O₂ if possible 1.0). Avoid any interruptions in chest compressions. After every single defibrillation attempt (initially biphasic 120-200 J, monophasic 360 J, subsequently with the respective highest energy), chest compressions are initiated again immediately for 2 min independent of the ECG rhythm. Tracheal intubation is the optimal method for securing the airway during resuscitation but should be performed only by experienced airway management providers. Laryngoscopy is performed during ongoing chest compressions; interruption of chest compressions for a maximum of 10 s to pass the tube through the vocal cords. Supraglottic airway devices are alternatives to tracheal intubation. Drug administration routes for adults and children: first choice i.v., second choice intraosseous (i.o.). Vasopressors: 1 mg epinephrine every 3-5 min i.v. After the third unsuccessful defibrillation amiodarone (300 mg i.v.), repetition (150 mg) possible. Sodium bicarbonate (50 ml 8.4%) only for excessive hyperkaliemia, metabolic acidosis, or intoxication with tricyclic antidepressants. Consider aminophylline (5 mg/kgBW). Thrombolysis during spontaneous circulation only for myocardial infarction or massive pulmonary embolism; during on-going cardiopulmonary resuscitation (CPR) only when indications of massive pulmonary embolism. Active compression-decompression (ACD-CPR) and inspiratory threshold valve (ITV-CPR) are not superior to good standard CPR.

CHILDREN

Most effective improvement of outcome by prevention of full cardiorespiratory arrest. Basic life support: initially five rescue breaths, followed by chest compressions (100-120/min depth about one third of chest diameter), compression-ventilation ratio 15:2. Foreign body airway obstruction with insufficient cough: alternate back blows and chest compressions (infants), or abdominal compressions (children >1 year). Treatment of potentially reversible causes: ("4 Hs and 4 Ts") hypoxia and hypovolaemia, hypokalaemia and hyperkalaemia, hypothermia, and tension pneumothorax, tamponade, toxic/therapeutic disturbances, thrombosis (coronary/pulmonary). Advanced life support: adrenaline (epinephrine) 10 µg/kgBW i.v. or i.o. every 3-5 min. Defibrillation (4 J/kgBW; monophasic or biphasic) followed by 2 min CPR, then ECG and pulse check. NEWBORNS: Initially inflate the lungs with bag-valve mask ventilation (p(AW) 20-40 cmH₂O). If heart rate remains <60/min, start chest compressions (120 chest compressions/min) and ventilation with a ratio 3:1. Maintain normothermia in preterm babies by covering them with foodgrade plastic wrap or similar. POSTRESUSCITATION PHASE: Early protocol-based intensive care stabilization; initiate mild hypothermia early regardless of initial cardiac rhythm [32-34°C for 12-24 h (adults) or 24 h (children); slow rewarming (<0.5°C/h)]. Consider percutaneous coronary intervention (PCI) in patients with presumed cardiac ischemia. Prediction of CPR outcome is not possible at the scene, determine neurological outcome <72 h after cardiac arrest with somatosensory evoked potentials, biochemical tests and neurological examination. ACUTE CORONARY SYNDROME: Even if only a weak suspicion of an acute coronary syndrome is present, record a prehospital 12-lead ECG. In parallel to pain therapy, administer aspirin (160-325 mg p.o. or i.v.) and clopidogrel (75-600 mg depending on strategy); in ST-elevation myocardial infarction (STEMI) and planned PCI also prasugrel (60 mg p.o.). Antithrombins, such as heparin (60 IU/kgBW, max. 4000 IU), enoxaparin, bivalirudin or fondaparinux depending on the diagnosis (STEMI or non-STEMI-ACS) and the planned therapeutic strategy. In STEMI define reperfusion strategy depending on duration of symptoms until PCI, age and location of infarction. TRAUMA: In severe hemorrhagic shock, definitive control of bleeding is the most important goal. For successful CPR of trauma patients a minimal intravascular volume status and management of hypoxia are essential. Aggressive fluid resuscitation, hyperventilation and excessive ventilation pressure may impair outcome in patients with severe hemorrhagic shock.

TRAINING

Any CPR training is better than nothing; simplification of contents and processes is the main aim.