Maskenbeatmung als Rückzugsstrategie zur endotrachealen Intubation

Higher pre-hospital anaesthesia case volumes result in lower mortality rates: implications for mass casualty care

Senior physicians with a higher pre-hospital anaesthesia case volume have higher first-pass tracheal intubation success rates, shorter on-site times, and lower patient mortality rates than physicians with lower case volumes. A senior physician's skill set includes the basics of management of airway and breathing (ventilating and oxygenating the patient), circulation, disability (anaesthesia), and environment (especially maintaining core temperature). Technical rescue skills may be required to care for patients requiring pre-hospital airway management especially in hazardous environments, such as road traffic accidents, chemical incidents, terror attacks or warfare, and natural disasters. Additional important tactical skills in mass casualty situations include patient triage, prioritising, allocating resources, and making transport decisions.

A comparison of airway management devices in simulated entrapment-trauma: a prospective manikin study

INTRODUCTION

In the patient entrapped after a motor vehicle collision (MVC), advanced airway management may need to be performed before extrication. The aim of this study was to compare four airway management devices utilized by paramedics in a simulated entrapped patient.

METHODS

Twenty-six paramedics performed advanced airway management on a manikin seated in the driver's seat (right side) of a car. Access was through the opened door only. The airway devices were the Macintosh laryngoscope and the Airtraq optical laryngoscope to facilitate the endotracheal intubation (ETI), the laryngeal mask airway (LMA) Supreme and the laryngeal tube (LT). Time to first successful ventilation and number of attempts required for successful placement were measured. Following each placement, participants rated the degree of difficulty. For ETI, participants ranked the achieved glottic view using Cormack-Lehane grades (CLG). Finally, participants were asked which airway management device they preferred.

RESULTS

The LMA Supreme had the shortest mean time to first successful ventilation (16.7 s, CI [0.95] 14.9-18.6). Insertion of the LMA Supreme and ETI with the Macintosh laryngoscope had 100% first-attempt success. The LMA Supreme was rated least difficult to insert (mean score 1.7/10 (CI [0.95] 1.2-2.1)). Compared to the Macintosh, the Airtraq laryngoscope facilitated superior laryngoscopy (CLG I view 46.2% and 80.8%, respectively). Most participants (10/26; 38%) chose the Macintosh laryngoscope as their preferred technique, followed closely by the LMA Supreme (9/26; 35%).

CONCLUSION

The LMA Supreme took the least amount of time and was the easiest to be inserted. Extraglottic airway devices may be beneficial alternative airway management devices to be considered by paramedics in the entrapped patient. Endotracheal intubation using the Macintosh laryngoscope was performed competently by participating paramedics. The Airtraq enabled superior laryngoscopy but resulted in poorer first-pass success rate.

Effects of Stomach Inflation on Cardiopulmonary Function and Survival During Hemorrhagic Shock: A Randomized, Controlled, Porcine Study

BACKGROUND

Ventilation of an unprotected airway may result in stomach inflation. The purpose of this study was to evaluate the effect of clinically realistic stomach inflation on cardiopulmonary function during hemorrhagic shock in a porcine model.

METHODS

Pigs were randomized to a sham control group (n = 9), hemorrhagic shock (35 mL kg over 15 min [n = 9]), and hemorrhagic shock combined with stomach inflation (35 mL kg over 15 min and 5 L stomach inflation [n = 10]).

RESULTS

When compared with the control group, hemorrhagic shock (n = 9) increased heart rate (103 ± 11 vs. 146 ± 37 beats min; P = 0.002) and lactate (1.4 ± 0.5 vs. 4.0 ± 1.9 mmol L; P < 0.001), and decreased mean arterial blood pressure (81.3 ± 12.8 vs. 35.4 ± 8.1 mmHg; P < 0.001) and stroke-volume index (38.1 ± 6.4 vs. 13.6 ± 4.8 mL min m; P < 0.001). Hemorrhagic shock combined with stomach inflation (n = 10) versus hemorrhagic shock only (n = 9) increased intra-abdominal pressure (27.0 ± 9.3 vs. 1.1 ± 1.0 mmHg; P < 0.001), and decreased stroke-volume index (9.9 ± 6.0 vs. 20.8 ± 8.5 mL min m; P = 0.007), and dynamic respiratory system compliance (10.8 ± 4.5 vs. 38.1 ± 6.1 mL cmH2O; P < 0.001). Before versus after stomach evacuation during hemorrhagic shock, intra-abdominal pressure decreased (27.0 ± 9.3 vs. 9.8 ± 5.4 mmHg; P = 0.042). Survival in the sham control and hemorrhagic shock group was 9 of 9, respectively, and 3 of 10 after hemorrhagic shock and stomach inflation (P < 0.001).

CONCLUSIONS

During hemorrhagic shock stomach inflation caused an abdominal compartment syndrome and thereby impaired cardiopulmonary function and aerobic metabolism, and increased mortality. Subsequent stomach evacuation partly reversed adverse stomach-inflation triggered effects.

[Anesthesia for medical students : A brief guide to practical anesthesia in adults with a web-based video illustration]

In Germany, Austria and Switzerland, anesthesiologists are the second largest group of physicians in hospitals, but this does not correspond to the amount of anesthesiology teaching that medical students receive in medical schools. Accordingly, the chances of medical students recognizing anesthesiology as a promising personal professional career are smaller than in other disciplines with large teaching components. Subsequent difficulties to recruit anesthesiology residents are likely, although many reasons support anesthesiology as a professional career.Traditional strategies to teach medical students in anesthesiology in medical school consist of airway management or cardiopulmonary resuscitation attempts in manikins. Anesthesiology is a complex interaction consisting of anatomy, physiology, pharmacology, clinical evaluation, experience, knowledge, and manual skills. While some medical schools offer teaching in high fidelity simulators, clinical teaching in the operating room is often limited. When medical students opt for a clinical rotation in anesthesiology, there is a chance to demonstrate the fascinating world of anesthesiology, but this chance has to be utilized carefully by anesthesiologists, as young talents have to be discovered, supported, and challenged.We have put together a short guide for medical students for a clinical rotation in anesthesiology in adults in order to generate basic knowledge and interest in anesthesiology as well as a sense of achievement. Basic knowledge about premedication, induction, maintenance and strategies for anesthesia is discussed. Further, the most important anesthesia drugs are discussed and manual skills, such as intravenous cannulation, mask ventilation, intubation, and regional anesthesia are featured with QR-code based video illustrations on a smartphone or personal computer. We did not discuss possible local mannerism and special patient groups (e. g., children, special medical history), local guidelines, or standard operating procedures.Medical students can be inspired by anesthesiology when not simply told about the tools of the trade and strategies, but instead by gaining knowledge and clinical skills that render a sense of achievement, likely during a clinical rotation into anesthesiology. A short theoretical instruction of anesthesiology enables rapid and targeted orientation even before a clinical rotation. Whether this subsequently results in a higher recruiting chance is currently unknown.

[Death due to (no) airway. Adverse events by out-of-hospital airway management?]

Securing the airway is a rarely performed procedure in the out-of-hospital setting. In recent years evidence has been accumulated indicating that out-of-hospital airway management is more challenging as compared to elective situations even for experienced health care providers. Furthermore, several authors have questioned the benefit of out-of-hospital tracheal intubation. This review argues the problems regarding out-of-hospital airway management studies and discusses potential solutions which may improve out-of-hospital health care.

[Extraglottic airway devices in the intensive care unit]

Extraglottic airway devices (EGA) are not only used in routine anaesthesia practice, they also have a distinct value for in-hospital and out-of-hospital difficult airway management. In the environment of the intensive care unit (ICU) EGA are not used on a regular basis. However, expertise and knowledge regarding EGA coming from the operating theatre or the out-of-hospital setting may also be of value for the ICU setting. This review presents the potential indications for EGA on the ICU for the management of difficult airway situations as well as during percutaneous tracheotomy. Furthermore, the possible advantages of EGA during postoperative recovery from anaesthesia as well as termination of controlled ventilation for intensive care patients are discussed.

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.

Effects of a suction laryngoscope in a model with simulated severe airway hemorrhage

In severe airway hemorrhage, simultaneous suction and laryngoscopy may render intubation difficult. We built a suction laryngoscope that consists of an adjustable stainless steel-guide tube fixed at the lingual surface of a standard Macintosh laryngoscope blade. Via this steel-guide tube, a large suction catheter can be inserted and positioned exactly to suction pharyngeal blood or vomitus, rendering simultaneous suctioning and laryngoscopy possible. In contrast to previous suction laryngoscopes, our suction catheter has a large lumen, which enables fast suctioning and exact placement by adjusting the steel-guide tube. To assess whether our suction laryngoscope could provide better intubation conditions in comparison to a standard Macintosh laryngoscope in a bleeding airway scenario, 44 medical students intubated a manikin with severe simulated airway hemorrhage using our suction laryngoscope and a standard Macintosh laryngoscope in random order. There was no significant difference in time needed for intubation when using the suction versus the Macintosh laryngoscope (mean +/- SD: 43 +/- 13 vs 52 +/- 31 s; P = 0.07), but the number of esophageal intubations was significantly lower when using the suction laryngoscope [6 of 44 (13.6%) vs 19 of 44 (43.2%); P = 0.004]. In conclusion, when compared with a standard Macintosh laryngoscope, using a suction laryngoscope did not result in more rapid intubation, but significantly decreased the likelihood of esophageal intubations.

Influence of airway management strategy on "no-flow-time" during an "advanced life support course" for intensive care nurses - a single rescuer resuscitation manikin study

Background

In 1999, the laryngeal tube (VBM Medizintechnik, Sulz, Germany) was introduced as a new supraglottic airway. It was designed to allow either spontaneous breathing or controlled ventilation during anaesthesia; additionally it may serve as an alternative to endotracheal intubation, or bag-mask ventilation during resuscitation. Several variations of this supraglottic airway exist. In our study, we compared ventilation with the laryngeal tube suction for single use (LTS-D) and a bag-mask device. One of the main points of the revised ERC 2005 guidelines is a low no-flow-time (NFT). The NFT is defined as the time during which no chest compression occurs. Traditionally during the first few minutes of resuscitation NFT is very high. We evaluated the hypothesis that utilization of the LTS-D could reduce the NFT compared to bag-mask ventilation (BMV) during simulated cardiac arrest in a single rescuer manikin study.

Methods

Participants were studied during a one day advanced life support (ALS) course. Two scenarios of arrhythmias requiring defibrillation were simulated in a manikin. One scenario required subjects to establish the airway with a LTS-D; alternatively, the second scenario required them to use BMV. The scenario duration was 430 seconds for the LTS-D scenario, and 420 seconds for the BMV scenario, respectively. Experienced ICU nurses were recruited as study subjects. Participants were randomly assigned to one of the two groups first (LTS-D and BMV) to establish the airway. Endpoints were the total NFT during the scenario, the successful airway management using the respective device, and participants' preference of one of the two strategies for airway management.

Results

Utilization of the LTS-D reduced NFT significantly (p < 0.01). Adherence to the time frame of ERC guidelines was 96% in the LTS-D group versus 30% in the BMV group. Two participants in the LTS-D group required more than one attempt to establish the LTS-D correctly. Once established, ventilation was effective in 100%. In a subjective evaluation all participants preferred the LTS-D over BMV to provide ventilation in a cardiac arrest scenario.

Conclusion

In our manikin study, NFT was reduced significantly when using LTS-D compared to BMV. During cardiac arrest, the LTS-D might be a good alternative to BMV for providing and maintaining a patent airway. For personnel not experienced in endotracheal intubation it seems to be a safe airway device in a manikin use.

[Application of the current resuscitation guidelines 2005. Case report of successful cardiopulmonary resuscitation]

The international guidelines for cardiopulmonary resuscitation are subject to continuous modification and were revised in November 2005. This report describes a case of an out-of-hospital cardiopulmonary resuscitation where the patient survived a cardiac arrest without neurological sequelae after chest compression (30:2), bag-mask ventilation and multiple biphasic defibrillation (single shocks). This article gives a practical review of the most important new recommendations in the current resuscitation guidelines. The accomplished measures are discussed on the background of the new recommendations.

Advanced Trauma Life Support® – ein Versorgungsstandard für Deutschland?

Over the last 30 years the Advanced Trauma Life Support (ATLS) course has become the most successful training program in the world for the early care of severely injured patients. It has shaped trauma care systems in many countries and is now on the verge of being introduced into Germany by the German Society of Trauma Surgery (DGU). However, after publication of the latest edition in 2004 there are rising concerns regarding the lack of multi-disciplinarity, out-dated contents and lack of adaptability to regional needs. This article questions the beneficial effect of ATLS on the advanced German trauma care system and concludes that ATLS is not likely to improve trauma care in Germany.

[Emergency treatment of thoracic trauma]

Thoracic trauma, most often associated with other serious injuries, is the main cause of death in the first 45 years of life. The percentage of chest injuries in multiple trauma, mainly from blunt impact, has remained relatively constant at 80% during the last 30 years. Isolated thoracic injuries comprise only 25% of all trauma cases, 90% of chest injuries are due to blunt impact, while penetrating injuries make up 5-10%. Since 25% of deaths from trauma are attributable to chest injuries, they determine the survival rate in multiple trauma to a significant extent. The pattern of chest injuries is variable, frequently in different combinations comprising rib cage and diaphragm, lung parenchyma, airway and mediastinal organs. This article details the immediate simultaneous diagnostic and therapeutic procedures in the prehospital phase, management in the emergency room, the relative importance of computed tomography, ultrasound examination and endoscopy in the primary diagnostic evaluation and the principles of anaesthetic management of thoracic trauma.

The Out-of-Hospital Esophageal and Endobronchial Intubations Performed by Emergency Physicians

BACKGROUND

Rapid establishment of a patent airway in ill or injured patients is a priority for prehospital rescue personnel. Out-of-hospital tracheal intubation can be challenging. Unrecognized esophageal intubation is a clinical disaster.

METHODS

We performed an observational, prospective study of consecutive patients requiring transport by air and out-of-hospital tracheal intubation, performed by primary emergency physicians to quantify the number of unrecognized esophageal and endobronchial intubations. Tracheal tube placement was verified on scene by a study physician using a combination of direct visualization, end-tidal carbon dioxide detection, esophageal detection device, and physical examination.

RESULTS

During the 5-yr study period 149 consecutive out-of-hospital tracheal intubations were performed by primary emergency physicians and subsequently evaluated by the study physicians. The mean patient age was 57.0 (+/-22.7) yr and 99 patients (66.4%) were men. The tracheal tube was determined by the study physician to have been placed in the right mainstem bronchus or esophagus in 16 (10.7%) and 10 (6.7%) patients, respectively. All esophageal intubations were detected and corrected by the study physician at the scene, but 7 of these 10 patients died within the first 24 h of treatment.

CONCLUSION

The incidence of unrecognized esophageal intubation is frequent and is associated with a high mortality rate. Esophageal intubation can be detected with end-tidal carbon dioxide monitoring and an esophageal detection device. Out-of-hospital care providers should receive continuing training in airway management, and should be provided additional confirmatory adjuncts to aid in the determination of tracheal tube placement.

[The new 2005 resuscitation guidelines of the European Resuscitation Council: comments and supplements]

The new CPR guidelines are based on a scientific consensus which was reached by 281 international experts. Chest compressions (100/min, 4-5 cm deep) should be performed in a ratio of 30:2 with ventilation (tidal volume 500 ml, Ti 1 s, FIO2 if possible 1.0). After a single defibrillation attempt (initially biphasic 150-200 J, monophasic 360 J, subsequently with the respective highest energy), chest compressions are initiated again immediately for 2 min. Endotracheal intubation is the gold standard; other airway devices may be employed as well depending on individual skills. Drug administration routes for adults and children: first choice IV, second choice intraosseous, third choice endobronchial [epinephrine dose 2-3x (adults) or 10x (pediatric patients) higher than IV]. Vasopressors: 1 mg epinephrine every 3-5 min IV. After the third unsuccessful defibrillation attempt amiodarone IV (300 mg); repetition (150 mg) possible. Sodium bicarbonate (1 ml/kg 8.4%) only in excessive hyperkalemia, metabolic acidosis, or intoxication with tricyclic antidepressants. Consider atropine (3 mg) and aminophylline (5 mg/kg). Thrombolysis during spontaneous circulation only in myocardial infarction or massive pulmonary embolism; during CPR only during massive pulmonary embolism. Cardiopulmonary bypass only after cardiac surgery, hypothermia or intoxication. Pediatrics: best improvement in outcome by preventing cardiocirculatory collapse. Alternate chest thumps and chest compression (infants), or abdominal compressions (>1-year-old) in foreign body airway obstruction. Initially five breaths, followed by chest compressions (100/min; approximately 1/3 of chest diameter): ventilation ratio 15:2. Treatment of potentially reversible causes (4 "Hs", "HITS": hypoxia, hypovolemia, hypo- and hyperkaliemia, hypothermia, cardiac tamponade, intoxication, thrombo-embolism, tension pneumothorax). Epinephrine 10 microg/kg IV or intraosseously, or 100 microg (endobronchially) every 3-5 min. Defibrillation (4 J/kg; monophasic oder biphasic) followed by 2 min CPR, then ECG and pulse check. Newborns: inflate the lungs with bag-valve mask ventilation. If heart rate<60/min chest compressions:ventilation ratio 3:1 (120 chest compressions/min). Postresuscitation phase: initiate mild hypothermia [32-34 degrees C for 12-24 h; slow rewarming (<0.5 degrees C/h)]. Prediction of CPR outcome is not possible at the scene; determining neurological outcome within 72 h after cardiac arrest with evoked potentials, biochemical tests and physical examination. Even during low suspicion for an acute coronary syndrome, record a prehospital 12-lead ECG. In parallel to pain therapy, aspirin (160-325 mg PO or IV) and in addition clopidogrel (300 mg PO). As antithrombin, heparin (60 IU/kg, max. 4000 IU) or enoxaparine. In ST-segment elevation myocardial infarction, define reperfusion strategy depending on duration of symptoms until PCI (prevent delay>90 min until PCI). Stroke is an emergency and needs to be treated in a stroke unit. A CT scan is the most important evaluation, MRT may replace a CT scan. After hemorrhage exclusion, thrombolysis within 3 h of symptom onset (0.9 mg/kg rt-PA IV; max 90 mg within 60 min, 10% of the entire dosage as initial bolus, no aspirin, no heparin within the first 24 h). In severe hemorrhagic shock, definite 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 severe hemorrhagic shock. Despite bad prognosis, CPR in trauma patients may be successful in select cases. Any CPR training is better than nothing; simplification of contents and processes remains important.

Beatmung eines ungeschützten Atemwegs

BACKGROUND

Currently 30 chest compressions and 2 ventilations with an inspiratory time of 1 s are recommended during cardiopulmonary resuscitation with an unprotected airway, thus spending about 15% instead of 40% of resuscitation time on ventilation. Time could be gained for chest compressions when reducing inspiratory time from 2 s to 1 s, however, stomach inflation may increase as well.

METHODS

In an established bench model we evaluated the effect of reducing inspiratory time from 2 s to 1 s at different lower oesophageal sphincter pressure (LOSP) levels using a novel peak inspiratory-flow and peak airway-pressure-limiting bag-valve-mask device (Smart-Bag).

RESULTS

A reduction of inspiratory time from 2 s to 1 s resulted in significantly lower peak airway pressure with LOSP of 0.49 kPa (5 cm H2O), 0.98 kPa (10 cm H2O) and 1.47 kPa (15 cm H2O) and an increase with 1.96 kPa (20 cm H2O). Lung tidal volume was reduced with 1 s compared to 2 s. When reducing inspiratory time from 2 s to 1 s, stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O).

CONCLUSIONS

In this model of a simulated unprotected airway, a reduction of inspiratory time from 2 s to 1 s using the Smart-Bag resulted in comparable inspiratory peak airway pressure and lower, but clinically comparable, lung tidal volume. Stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O), and was higher with an inspiratory time of 2 s vs 1 s.

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.