Methoden des Atemwegsmanagements in der pr�klinischen Notfallmedizin

[Statement of the Austrian Society for Anesthesiology, Resuscitation and Intensive Care Medicine (ÖGARI) on the use of laryngeal tubes by ambulancemen and paramedics]

Due to an increasing number of severe complications reported during the prehospital application of laryngeal tubes, the Austrian Society for Anesthesiology, Resuscitation and Intensive Care Medicine (ÖGARI) is prompted to formulate a respective statement. With regard to the current training situation and the applicable laws, ÖGARI recommends to convert the "Emergency Competence for Endotracheal Intubation (NKI)" for emergency paramedics into an "Emergency Competence for Extraglottic Airway Management, (NK-EGA)". Training should include at least 40 h of theoretical instruction, hands-on training on the manikin to secure mastery of the methodology and at least 20 successful applications under clinically elective conditions in adult patients under direct medical supervision. Here, depending on local conditions, both laryngeal mask and laryngeal tube can be used. In the prehospital environment, the device must be used which has been trained as mentioned above. Only 2nd generation EGA should be used. After successful EGA placement timely cuff pressure monitoring and gastric suction should be performed. The use of an EGA by ambulance-men cannot be recommended; these have to be limited to bag-mask ventilation.

[Emergency anesthesia, airway management and ventilation in major trauma. Background and key messages of the interdisciplinary S3 guidelines for major trauma patients]

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate  < 6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S(p)O(2)  < 90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)  < 9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)  < 90 mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate  > 29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices need to be available preclinical and a fiber-optic endoscope should be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful endotracheal intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.

[Emergency anesthesia, airway management and ventilation in major trauma. Background and key messages of the interdisciplinary S3 guidelines for major trauma patients]

Patients with multiple trauma presenting with apnea or a gasping breathing pattern (respiratory rate <6/min) require prehospital endotracheal intubation (ETI) and ventilation. Additional indications are hypoxia (S(p)O(2)<90% despite oxygen insufflation and after exclusion of tension pneumothorax), severe traumatic brain injury [Glasgow Coma Scale (GCS)<9], trauma-associated hemodynamic instability [systolic blood pressure (SBP)<90 mmHg] and severe chest trauma with respiratory insufficiency (respiratory rate >29/min). The induction of anesthesia after preoxygenation is conducted as rapid sequence induction (analgesic, hypnotic drug, neuromuscular blocking agent). With the availability of ketamine as a viable alternative, the use of etomidate is not encouraged due to its side effects on adrenal function. An electrocardiogram (ECG), blood pressure measurement and pulse oximetry are needed to monitor the emergency anesthesia and the secured airway. Capnography is absolutely mandatory to confirm correct placement of the endotracheal tube and to monitor tube dislocations as well as ventilation and oxygenation in the prehospital and hospital setting. Because airway management is often complicated in trauma patients, alternative devices and a fiber-optic endoscope need to be available within the hospital. Use of these alternative measures for airway management and ventilation should be considered at the latest after a maximum of three unsuccessful intubation attempts. Emergency medical service (EMS) physicians should to be trained in emergency anesthesia, ETI and alternative methods of airway management on a regular basis. Within hospitals ETI, emergency anesthesia and ventilation are to be conducted by trained and experienced anesthesiologists. When a difficult airway or induction of anesthesia is expected, endotracheal intubation should be supervised or conducted by an anesthesiologist. Normoventilation should be the goal of mechanical ventilation. After arrival in the resuscitation room the ventilation will be controlled and guided with the help of arterial blood gas analyses. After temporary removal of a cervical collar, the cervical spine needs to be immobilized by means of manual in-line stabilization when securing the airway.

Initial ventilation through laryngeal tube instead of face mask in out-of-hospital cardiopulmonary arrest is effective and safe

INTRODUCTION

Bag-valve-mask ventilation is recommended as the initial airway management option for paramedics during cardiopulmonary resuscitation, although this technique requires considerable skill and is associated with the risk of stomach insufflation, regurgitation, and aspiration. The present two-phase study investigated the efficacy and safety of the laryngeal tube (LT-D) used by paramedics as the sole technique for ventilation in out-of-hospital cardiac arrest.

METHODS

Paramedics staffing the emergency services' ambulances were selected for the study and trained in the use of the LT-D (phase I). They were then requested to use the device in patients requiring out-of-hospital cardiopulmonary resuscitation without prior bag-valve-mask ventilation. Patients were evaluated with regard to successful placement and effective ventilation using the airway. On arrival at the scene, the emergency physician replaced the LT-D with an endotracheal tube and assessed the incidence of regurgitation and injuries to the airways (phase II).

RESULTS

Forty patients were enrolled into this study. One was excluded from analysis because of protocol violation. Insertion of the LT-D was successful and ventilation was effective in 33 patients (85%). Ventilation was not possible in six patients (15%) because of cuff rupture (n = 3) or massive regurgitation and aspiration before LT-D insertion (n = 3). No patient regurgitated after tube placement. No airway injuries were observed. The participants rated ventilation using the LT-D as effective.

CONCLUSION

The LT-D is feasible and effective for airway management and ventilation when used by paramedics in out-of-hospital cardiopulmonary resuscitation and can be recommended as the sole technique in such situations.

[Intrahospital transport of critically ill patients]

Transport of critically ill patients from the ICU for diagnostic and therapeutic purposes (e.g. CT, endoscopy, radiological catheter-assisted interventions) is a challenge and has steadily increased over the years. After risk-benefit analysis careful planning is the first step in minimizing the risk of complications. Knowledge and skillful handling of the transport equipment is mandatory to avoid life-threatening incidents as monitoring and therapy have to be continued during the transport. Proper education and experience in critical care medicine are additional characteristics of the transport team. When these prerequisites are fulfilled a "non-transportable" patient is just as unlikely as a "non-anesthetizable" patient.

Automated emergency ventilation devices in a simulated unprotected airway

BACKGROUND

Automated ventilation devices are becoming more popular for emergency ventilation, but there is still not much experience concerning the optimal ventilation mode.

METHODS

In a bench model representing a non-intubated patient in respiratory and cardiac arrest, we compared a pressure-cycled with a time- and volume-cycled automated ventilation device in their completely automated modes. The main study endpoints were inspiratory time, respiratory rate, stomach inflation, and lung tidal volumes.

RESULTS

The pressure-cycled device inspired for 6.7 s in the respiratory arrest setting (respiratory rate 5.6/min), and never reached its closing pressure in the cardiac arrest setting (respiratory rate 1 breath/min). The time- and volume-cycled device inspired in both settings for 1.7 s (respiratory rate 13 breaths/min). In the respiratory arrest setting, mask leakage was 620 ± 20 mL for the pressure-cycled device vs. 290 ± 10 mL for the time- and volume-cycled device (p < 0.0001); lung tidal volume was 1080 ± 50 mL vs. 490 ± 20 mL, respectively (p < 0.0001); and there was no stomach inflation for either device. In the cardiac arrest setting, pressure-cycled device mask leakage was 5460 ± 60 mL vs. 240 ± 20 mL (p < 0.0001) for the time- and volume-cycled device (p < 0.0001); stomach inflation was 13,100 ± 100 mL vs. 90 ± 10 mL, respectively (p < 0.0001); and lung tidal volume 740 ± 60 mL vs. 420 ± 20 mL, respectively (p < 0.0001).

CONCLUSION

In a simulated respiratory arrest setting, ventilation with an automated pressure-cycled ventilation device resulted in lower respiratory frequency and larger tidal volumes compared to a time- and volume-cycled device. In a simulated cardiac arrest setting, ventilation with an automated pressure-cycled ventilation device, but not a time- and volume-cycled device, resulted in continuous gastric insufflation.

Minimizing stomach inflation versus optimizing chest compressions

In a bench model, we evaluated a bag-valve device (Smart Bag MO) with limited maximum inspiratory gas flow developed to reduce the risk of stomach inflation in an unprotected airway. During simulated cardiopulmonary resuscitation with uninterrupted chest compressions, ventilation with the "disabled" Smart Bag MO or an adult self-inflating bag-valve device provided only adequate tidal volumes if inspiratory time was 0.5 s. Ventilation with the "enabled" Smart Bag MO, even in ventilation windows of 0.5 s, provided inadequate tidal volumes during simulated cardiopulmonary resuscitation and would result in hypoventilation in a patient.

Präklinisches Atemwegsmanagement in Norddeutschland

BACKGROUND

Out-of-hospital airway management confronts emergency medical teams with complex challenges. To date no specific data are available on the qualifications of emergency physicians (EPs) and the quality of emergency equipment in northern Germany.

MATERIALS AND METHODS

This study surveyed individual EPs at regional emergency dispatch centres about their personal knowledge and skills, and the procedures and equipment used in out-of-hospital airway management.

RESULTS

A total of 606 EPs from 59 of the 66 (89.4%) regional emergency dispatch centres surveyed responded and 56.1% of the EPs questioned were anesthesiologists. The other EPs were qualified in either internal medicine (22.6%), surgery (12.4%), general medicine (5.6%) or other specialties (3.3%). All (100%) of the EPs trained in anesthesia and 35.2% of the other EPs reported that they had performed more than 100 in-hospital endotracheal intubations (ETI). 93% of all EPs rated out-of-hospital ETI as more difficult than in-hospital ETI. A total of 33.0% of anesthesia-trained EPs and 6.1% of the other EPs used muscle relaxants for ETI in more than 20% of the cases. Of the anesthesia-trained EPs 38.1% used expiratory CO(2) monitoring to verify tube placement compared to 12.1% of the other EPs. A total of 97.8% of anesthesia-trained EPs reported having used an extra-glottic airway device more than 20 times compared to 11.1% of the other EPs. For the emergency equipment 44.4% included an extraglottic airway device, 57.8% a cricothyrotomy set and 27.1% CO(2) monitoring options.

CONCLUSION

Neither the emergency equipment nor the physicians' knowledge and skills were sufficient to meet the special demands of out-of-hospital airway management, particularly among non-anesthesiologists.

LMA CTrach™

BACKGROUND

The Intubating LMA was designed to facilitate blind intubation and to provide ventilation between two intubation attempts. However, blind intubation can be associated with a risk of oesophageal penetration, therefore, a flexible bronchoscope is frequently used to assist tracheal intubation. This leads to increased burdens on materials and personal resources and prolongs intubation times. Hence the LMA CTrach laryngeal mask airway (CTrach) was developed with an integrated fibreoptic system which can be connected to a monitor for visualisation of the larynx during intubation.

METHODS

We detail the initial experience gained with the practical handling of the CTrach and the application in 10 patients with difficult-to-manage airways. Laryngeal views were graduated in a CTrach-specific classification from grade I (clear view of the arytenoids, glottis and epiglottis) to grade IV (no part of the larynx can be identified). Adjusting manoeuvres were defined to improve the view of laryngeal structures.

RESULTS

All patients could be successfully ventilated with the CTrach. Ventilation quality was rated adequate in nine and possible in one patient. The initial distribution of the laryngeal view between grades I-IV was 1/2/1/6 and after adjusting manoeuvres to improve the laryngeal view the grade distribution was 3/5/0/2. Intubation through the CTrach was successful in all patients, nine at first and one at the second attempt.

CONCLUSION

In this small sample of patients with difficult-to-manage airways, the CTrach yielded high success rates for both ventilation and tracheal intubation. Adjusting manoeuvres can improve the laryngeal view further.

Der Lawinennotfall

In North America and Europe around 140 persons die every year due to avalanches, approximately 35 in North America, 100 in the European Alps, and 5 in other parts of Europe. Most of the victims are skiers and snowboarders. This article outlines the specific pathophysiology of avalanche burials, such as hypoxia, hypercapnia, and hypothermia and also other factors which influence survival. Strategies to minimize the mortality due to avalanches and the on-site treatment of buried persons are discussed. Finally, possibilities to reduce the number of avalanche deaths are pointed out.

[Prehospital management of spinal cord injuries]

In both the United States and Europe about 10,000 patients suffer from spinal cord injury (SCI) each year and 20% die before being admitted to hospital. Prehospital management of SCI is very important since 25% of SCI damage may occur after the initial event. Emergency treatment includes examination of the patient, spinal immobilization, careful airway management, cardiovascular stabilization (maintenance of mean arterial blood pressure above 90 mmHg) and glucose levels within the normal range. From an evidence-based point of view, it is still not known whether additional specific therapy is useful and studies have not convincingly demonstrated that methylprednisolone (MPS) or other substances have clinically important benefits. Recently published statements from the US do not support the therapeutic use of MPS in patients suffering from SCI in the prehospital setting. Moreover, it is not known whether hypothermia or any other pharmacological interventions have beneficial effects. Networks for clinical studies in SCI patients should be established as a basic requirement for further improvement in outcome in these patients.

Invasive Techniken in der Notfallmedizin

Cricothyrotomy is a very invasive technique to secure the airway in an emergency but is irreplacable when less invasive techniques fail or cannot be instigated under the prevailing circumstances. Various techniques have been reported which can be subdivided into anatomical-surgical preparation or puncture techniques. The preferred strategy is mostly oriented towards the departmental standard procedure which will be decided by the clinical situation. Training for each procedure can be carried out in intensive care departments, and using autopsy material or a manekin. Various methods of cricothyrotomy will be discussed here, and additionally an anatomical preparation and two puncture techniques will be demonstrated in detail.

[Preclinical management of multiple trauma]

Approximately 8000 patients with multiple trauma are admitted annually to an emergency room in Germany. The prognosis of these severely injured patients is influenced in particular by concomitant craniocerebral injury, an abdominal wound, or thoracic trauma. Hypoxia and hypotension subsequent to shock induced by hemorrhagic-traumatic effects are of prime importance. Preclinical management thus includes examining the injured patient, immobilizing the spine, ensuring airway patency, stabilizing cardiovascular status suitting the approach to the injury pattern, commensurate care of partial injuries, pain therapy, as well as rapid and careful transportation to the nearest qualified trauma center. Management of patients with multiple trauma poses a particular challenge to the responding team. This article in the continuing education series deals with current algorithms for preclinical management of patients with multiple injuries with particular focus on the significant factor of time.