Simulated ventilation of two patients with a single ventilator in a pandemic setting

Simultaneous ventilation of two patients may lead to hypoventilation in one patient and hyperinflation in the other patient. In a simulation of ventilation in two patients using artificial lungs, we voluntarily directed gas flow to one patient by using three-dimensional-printed Y-adapters and stenosis adapters during volume- and pressure-controlled ventilation in the first set up. We continuously modified the model using a special one-way valve on the flow-limited side and measured it in pressure-controlled ventilation with the flow sensor of the ventilator adjusted on both sides in a second and third setup. In the first setup, volume- or pressure-controlled ventilation resulted in comparable minute volumes in both lungs, even when one side was obstructed to 3 mm. In the second setup, with a 3-mm flow limitation, we had a minute ventilation of 9.4 ± 0.3 vs. 3.5 ± 0.1 L/min. In the third setup, ventilation with a 3-mm flow limitation resulted in minute ventilation of 7.2 ± 0.2 vs. 5.70 L/min at a compliance of 30 vs. 70 mL/mbar. It is possible to override the safety features of a modern intensive care ventilator and thus direct tidal volumes in different lung conditions to one lung using three-dimensional-printed flow limiters. While this ventilation setting was technically feasible in a bench model, it would be unstable, if not dangerous, in a clinical situation.

The efficacy of apneic oxygenation during intubation using a prototype of an oxygenation laryngoscope - a technical simulation

BACKGROUND

Recently, a non-commercial oxygenation laryngoscope was able to maintain apneic oxygenation during simulated intubation efforts. Since that prototype was 3 mm wider than a standard Macintosh laryngoscope blade, the intubation performance of this device may differ from standard blades. A new prototype of an oxygenation laryngoscope was developed, consisting of a standard-size Macintosh blade and a fixed oxygen supply line to the side. Actually, it is unclear at which point of this blade the oxygen supply line should end to facilitate the best possible oxygen supply for apneic oxygenation.

METHODS

In this simulation study using a standardized human airway manikin, the efficacy of apneic oxygenation by oxygen insufflation using standard and modified Macintosh blades was compared: a standard Macintosh blade without oxygen supply line as control, one with an additional oxygen supply line ending proximal near the handle, one with the line ending at the middle of the blade, and one with the line ending near the tip. A preoxygenated test lung was connected to an oximeter with a flow rate of 200ml/min, simulating oxygen consumption of a male adult, and to the trachea of an anatomically correctly shaped airway manikin. Apneic oxygenation was performed and oxygen content was measured over a 20-minutes observation period. Experiments were repeated five times for each laryngoscope blade.

RESULTS

Oxygen percentage in the test lung dropped from 100 ± 0% at the start of the experiment to 53 ± 1.5% in the room air control group (p < 0.001 compared to all other groups), and to 74 ± 2.5% in the proximal oxygen line group, whereas oxygen percentage remained at 100% in both the medium and distal oxygen line groups (p = 1 between these groups; p < 0.001 between all other groups).

CONCLUSIONS

In this simulation study with a preoxygenated airway manikin, the use of a modified Macintosh laryngoscope blade with oxygen line attached at the tip or at the middle were able to maintain apneic oxygenation without measurable drop of oxygen content over 20 min. Proximal placement of the oxygen supply line still showed an advantage against room air, however it did not completely prevent room air from entering the airway.

TRIAL REGISTRATION

Not applicable.

Oral transmucosal fentanyl citrate analgesia in prehospital trauma care: an observational cohort study

BACKGROUND

Pain is one of the major prehospital symptoms in trauma patients and requires prompt management. Recent studies have reported insufficient analgesia after prehospital treatment in up to 43% of trauma patients, leaving significant room for improvement. Good evidence exists for prehospital use of oral transmucosal fentanyl citrate (OTFC) in the military setting. We hypothesized that the use of OTFC for trauma patients in remote and challenging environment is feasible, efficient, safe, and might be an alternative to nasal and intravenous applications.

METHODS

This observational cohort study examined 177 patients who were treated with oral transmucosal fentanyl citrate by EMS providers in three ski and bike resorts in Switzerland. All EMS providers had previously been trained in administration of the drug and handling of potential adverse events.

RESULTS

OTFC caused a statistically significant and clinically relevant decrease in the level of pain by a median of 3 (IQR 2 to 4) in NRS units (P < 0.0001). Multiple linear regression analysis showed a significant absolute reduction in pain, with no differences in all age groups and between genders. No major adverse events were observed.

CONCLUSIONS

Prehospital administration of OTFC is safe, easy, and efficient for extrication and transport across all age groups, gender, and types of injuries in alpine environments. Side effects were few and mild. This could provide a valuable alternative in trauma patients with severe pain, without the delay of inserting an intravenous line, especially in remote areas, where fast action and easy administration are important.

Identification of the Optimal Position of a Nasal Oxygen Cannula for Apneic Oxygenation: A Technical Simulation

Background: In a cannot-ventilate-cannot-intubate situation, careful preoxygenation with high FiO2 allowing subsequent apneic oxygenation can be life-saving. The best position for an oxygen supply line within the human airway at which oxygen insufflation is more effective than standard preoxygenation with a face mask is unknown. Methods: In this experimental study, we compared the effectiveness of preoxygenation by placing an oxygen cannula at the nose entrance, through the nose at the soft palatine, or at the base of the tongue; as a control we used ambient air. We connected a fully preoxygenated test lung on one side to an oximeter with a flow rate of 200 mL/min simulating the oxygen consumption of a normal adult on the other side of the trachea of an anatomically correctly shaped airway manikin over a 20 min observation period five times for each cannula placement in a random order. Results: The oxygen percentage in the test lung dropped from 100% in all groups to 53 ± 1% in the ambient air control group, to 87 ± 2% in the nasal cannula group, and to 96 ± 2% in the soft palatine group; it remained at 99 ± 1% in the base of the tongue group (p = 0.003 for the soft palatine vs. base of the tongue and p < 0.001 for all other groups). Conclusions: When simulating apneic oxygenation in a preoxygenated manikin, oxygen insufflation at the base of the tongue kept the oxygen percentage at baseline values of 99%, demonstrating a complete block of ambient air flowing into the airway of the manikin. Oxygen insufflation at the soft palatine or insufflation via a nasal cannula were less effective regarding this effect.

Stability of Drugs Stored in Helicopters for Use by Emergency Medical Services: A Prospective Observational Study

STUDY OBJECTIVE

Drugs stored in rescue helicopters may be subject to extreme environmental conditions. The aim of this study was to measure whether drugs stored under the real-life conditions of a Swiss helicopter emergency medical service (HEMS) would retain their potency over the course of 1 year.

METHODS

A prospective, longitudinal study measuring the temperature exposure and concentration of drugs stored on 2 rescue helicopters in Switzerland over 1 year. The study drugs included epinephrine, norepinephrine, amiodarone, midazolam, fentanyl, naloxone, rocuronium, etomidate, and ketamine. Temperatures were measured inside the medication storage bags and the crew cabins at 10-minute intervals. Drug stability was measured on a monthly basis over the course of 12 months using high-performance liquid chromatography. The medications were considered stable at a minimum remaining drug concentration of 90% of the label claim.

RESULTS

Temperatures ranged from -1.2 °C to 38.1 °C (29.84 °F to 100.58 °F) inside the drug storage bags. Of all the temperature measurements inside the drug storage bags, 37% lay outside the recommended storage conditions. All drugs maintained a concentration above 90% of the label claim. The observation periods for rocuronium and etomidate were shortened to 7 months because of a supply shortage of reference samples.

CONCLUSION

Drugs stored under the real-life conditions of Swiss HEMS are subjected to temperatures outside the manufacturer's approved storage requirements. Despite this, all drugs stored under these conditions remained stable throughout our study. Real-life stability testing could be a way to extend drug exchange intervals.

Airway management in a Helicopter Emergency Medical Service (HEMS): a retrospective observational study of 365 out-of-hospital intubations

Background

Airway management is a key skill in any helicopter emergency medical service (HEMS). Intubation is successful less often than in the hospital, and alternative forms of airway management are more often needed.

Methods

Retrospective observational cohort study in an anaesthesiologist-staffed HEMS in Switzerland. Patient charts were analysed for all calls to the scene (n = 9,035) taking place between June 2016 and May 2017 (12 months). The primary outcome parameter was intubation success rate. Secondary parameters included the number of alternative techniques that eventually secured the airway, and comparison of patients with and without difficulties in airway management.

Results

A total of 365 patients receiving invasive ventilatory support were identified. Difficulties in airway management occurred in 26 patients (7.1%). Severe traumatic brain injury was the most common indication for out-of-hospital Intubation (n = 130, 36%). Airway management was performed by 129 different Rega physicians and 47 different Rega paramedics. Paramedics were involved in out-of-hospital airway manoeuvres significantly more often than physicians: median 7 (IQR 4 to 9) versus 2 (IQR 1 to 4), p < 0.001.

Conclusion

Despite high overall success rates for endotracheal intubation in the physician-staffed service, individual physicians get only limited real-life experience with advanced airway management in the field. This highlights the importance of solid basic competence in a discipline such as anaesthesiology.

Influence of positive end-expiratory pressure on arterial blood pressure in mechanically ventilated trauma patients in the field: a retrospective cohort study

Ventilation with positive end-expiratory pressure (PEEP) may result in decreased venous return to the heart and therefore decrease cardiac output. We evaluated the influence of PEEP ventilation on arterial blood pressure in the field in 296 posttraumatic intubated patients being treated by a helicopter emergency medical service in a retrospective cohort study. Initial systolic blood pressure on the scene, upon hospital admission and their mean difference were compared between patients being ventilated with no/low PEEP (0–0.3 kPa) and moderate PEEP (0.3–1 kPa). In a subgroup analysis of initially hemodynamic unstable patients (systolic blood pressure < 80 mmHg), systolic blood pressure was compared between patients being ventilated with no/low or moderate PEEP Further, the mean difference between initial systolic blood pressure and upon hospital admission was correlated with the chosen PEEP. Systolic arterial blood pressure of patients being ventilated with no/low PEEP improved from 105 ± 36 mmHg to 112 ± 38 mmHg, and that of patients being ventilated with moderate PEEP improved from 105 ± 38 mmHg to 119 ± 27 mmHg. In initially unstable patients being ventilated with no/low PEEP systolic blood pressure improved from initially 55 ± 36 mmHg to 78 ± 30 mmHg upon hospital admission, and in those being ventilated with moderate PEEP, the systolic blood pressure improved from 43 ± 38 mmHg to 91 ± 27 mmHg. There was no significant correlation between the chosen PEEP and the mean difference of systolic blood pressure (Pearson’s correlation, r = 0.07, P = 0.17). Ventilation with moderate PEEP has no adverse effect on arterial systolic blood pressure in this cohort of trauma patients requiring mechanical ventilation. Initially unstable patients being ventilated with moderate PEEP tend to be hemodynamically more stable.

Nature Interest Scale - Development and Evaluation of a Measurement Instrument for Individual Interest in Nature

Interest is an important factor for successful learning that has been the subject of intensive research for decades. Although interest in nature is of great importance for environmental education, to date there is no valid and reliable measurement tool. Therefore, the purpose of this study was to develop and test a scale for interest in nature, the Nature Interest Scale (NIS). In study 1, nine items were selected based on the three dimensions of the psychological interest construct to represent interest in nature. The factor structure of this new measurement instrument, was tested using confirmatory factor analyses. The results show that the instrument represents the three dimensions of the interest construct well. In study 2 the validity (discriminant and convergent validity) as well as the reliability (internal consistency, composite reliability, test-retest reliability) of the NIS were demonstrated. In study 3, the applicability of the NIS was tested with a different target group, students with learning disabilities. The results of this factor analysis also confirm the factor structure of the scale. Thus, this study provides a valid and reliable measurement tool for individual interest in nature that can be used for future research.

Incidence and challenges of helicopter emergency medical service (HEMS) rescue missions with helicopter hoist operations: analysis of 11,228 daytime and nighttime missions in Switzerland

OBJECTIVE

We aimed to investigate the medical characteristics of helicopter hoist operations (HHO) in HEMS missions.

METHODS

We designed a retrospective study evaluating all HHO and other human external cargo (HEC) missions performed by Swiss Air-Rescue (Rega) between January 1, 2010, and December 31, 2019.

RESULTS

During the study period, 9,963 (88.7 %) HEMS missions with HHO and HEC were conducted during the day, and 1,265 (11.3 %) at night. Of the victims with time-critical injuries (NACA ≥ 4), 21.1 % (n = 400) reached the hospital within 60 min during the day, and 9.1 % (n = 18) at night. Nighttime missions, a trauma diagnosis, intubation on-site, and NACA Score ≥ 4 were independently and highly significantly associated with longer mission times (p < 0.001). The greatest proportion of patients who needed hoist or HEC operations in the course of the HEMS mission during the daytime sustained moderate injuries (NACA 3, n = 3,731, 37.5 %) while practicing recreational activities (n = 5,492, 55.1 %). In daytime HHO missions, the most common medical interventions performed were insertion of a peripheral intravenous access (n = 3,857, 38.7 %) and administration of analgesia (n = 3,121, 31.3 %).

CONCLUSIONS

Nearly 20 % of patients who needed to be evacuated by a hoist were severely injured, and complex and lifesaving medical interventions were necessary before the HHO procedure. Therefore, only adequately trained and experienced medical crew members should accompany HHO missions.

Temperature loss by ventilation in a calorimetric bench model

In intensive care medicine heat moisture exchangers are standard tools to warm and humidify ventilation gases in order to prevent temperature loss of patients or airway epithelia damage. Despite being at risk of hypothermia especially after trauma, intubated emergency medicine patients are often ventilated with dry and in winter probably cold ventilation gases. We tried to assess the amount of temperature-loss due to ventilation with cold, dry medical oxygen in comparison to ventilation with warm and humidified oxygen. We ventilated a 50-kg water-dummy representing the calorimetric capacity of a 60-kg patient over a period of 2 hours (tidal volume 6.6 mL/kg = 400 mL; respiratory rate 13/min). Our formal null-hypothesis was that there would be no differences in temperature loss in a 50 kg water-dummy between ventilation with dry oxygen at 10°C vs. ventilation with humidified oxygen at 43°C. After 2 hours the temperature in the water-dummy using cold and dry oxygen was 29.7 ± 0.1°C compared to 30.4 ± 0.1°C using warm and humidified oxygen. This difference in cooling rates between both ventilation attempts of 0.7 ± 0.1°C after 2 hours represents an increased cooling rate of ~0.35°C per hour. Ventilation with cool, dry oxygen using an automated transport ventilator resulted in a 0.35°C faster cooling rate per hour than ventilation with warm humidified oxygen in a bench model simulating calorimetric features of a 60-kg human body.

Nasal nalbuphine analgesia in prehospital trauma managed by first-responder personnel on ski slopes in Switzerland: an observational cohort study

BACKGROUND

Pain is one of the major symptoms complained about by patients in the prehospital setting, especially in the case of trauma. When there is mountainous topography, as in Switzerland, there may be a time delay between injury and arrival of professional rescuers, in particular on ski slopes. Administration of a safe opioid by first responders may improve overall treatment. We therefore assessed administration of nasal nalbuphine as an analgesic treatment for trauma patients in Switzerland.

METHODS

This observational cohort study examined 267 patients who were treated with nasal nalbuphine by first responders in six ski resorts in Switzerland. All first responders were instructed to begin treatment by assessing the feasibility of using nalbuphine to treat pain in the patient. A treatment algorithm was developed and distributed to assure that nalbuphine was only administered following a strict protocol. Data regarding pain scores and pain reduction after administration of nalbuphine were collected on-site. Refills were handed out to the first responders with the return of each completed questionnaire.

RESULTS

Nalbuphine provided effective pain relief, with the median level of pain on the numeric rating scale for pain reduced by 3 units on average, from 8 points (p < 0.001). The multivariate regression model showed that pain reduction was more pronounced in patients with higher initial pain levels. Nalbuphine was more effective in adolsecents than in patients aged 20 to 60 years (p = 0.006). No major side effects were observed.

CONCLUSION

Nasal administration of nalbuphine by first responders is a presumably safe and effective noninvasive pain management strategy for acutely injured patients in the prehospital setting. This may be an alternative, especially in the case of severe pain and prolonged time between arrival of the first responders and arrival of EMS/HEMS personnel on scene.

Oxygenation laryngoscope vs. nasal standard and nasal high flow oxygenation in a technical simulation of apnoeic oxygenation

Background

Failed airway management is the major contributor for anaesthesia-related morbidity and mortality. Cannot-intubate-cannot-ventilate scenarios are the most critical emergency in airway management, and belong to the worst imaginable scenarios in an anaesthetist’s life. In such situations, apnoeic oxygenation might be useful to avoid hypoxaemia. Anaesthesia guidelines recommend careful preoxygenation and application of high flow oxygen in difficult intubation scenarios to prevent episodes of deoxygenation. In this study, we evaluated the decrease in oxygen concentration in a model when using different strategies of oxygenation: using a special oxygenation laryngoscope, nasal oxygen, nasal high flow oxygen, and control.

Methods

In this experimental study we compared no oxygen application as a control, standard pure oxygen application of 10 l·min^− 1 via nasal cannula, high flow 90% oxygen application at 20 l·min^− 1 using a special nasal high flow device, and pure oxygen application via our oxygenation laryngoscope at 10 l·min^− 1. We preoxygenated a simulation lung to 97% oxygen concentration and connected this to the trachea of a manikin model simulating apnoeic oxygenation. Decrease in oxygen concentration in the simulation lung was measured continuously for 20 min.

Results

Oxygen concentration in the simulation lung dropped from 97 ± 1% at baseline to 40 ± 1% in the no oxygen group, to 80 ± 1% in the standard nasal oxygen group, and to 73 ± 2% in the high flow nasal oxygenation group. However, it remained at 96 ± 0% in the oxygenation laryngoscope group (p < 0.001 between all groups).

Conclusions

In this technical simulation, oxygenation via oxygenation laryngoscope was more effective than standard oxygen insufflation via nasal cannula, which was more effective than nasal high flow insufflation of 90% oxygen.

[Simulation of video-assisted retrieval of foreign bodies in the airway of children by nonmedical personnel]

BACKGROUND

Complete upper airway obstruction by a foreign body is a dramatic and acute emergency situation, and can result in rapid development of hypoxia, circulatory arrest and death. Special Magill pliers with an adjustable video optical system have been developed for airway inspection to facilitate efforts to remove foreign bodies causing obstruction of the upper airway.

OBJECTIVE

To remove a simulated airway foreign body from a cardiopulmonary resuscitation (CPR) manikin, either with normal Magill pliers or with the newly designed video Magill pliers.

MATERIAL AND METHODS

After a brief introduction, 81 kindergarten teachers, 51 pupils (age 10-14 years) and 52 prospective emergency physicians were asked to remove a 2 × 2 "Lego" brick from the hypopharynx of a CPR manikin using either standard Magill pliers or the newly designed video Magill pliers. The formal hypothesis was that there would be no differences between the methods. Successful removal was defined as when the first removal attempt resulted in the Lego brick passing beyond the teeth of the manikin within 60s.

RESULTS

The use of the video Magill pliers resulted in significantly higher success rates in removal of the simulated foreign airway body within 60 s compared to standard Magill pliers in kindergarten teachers (84% vs. 30%, p < 0.0001), pupils (84% vs. 18%, p < 0.0001) and prospective emergency physicians (92% vs. 40%, p < 0.0001). The time needed for removing the foreign airway body was significantly shorter in groups using the video Magill pliers (kindergarten teachers 29 ± 18s vs. 45 ± 19 s, pupils 29 ± 18s vs. 54 ± 14 s, and prospective emergency physicians 33 ± 18s vs. 45 ± 20 s; p < 0.0001). In an analogue points system (from 1 very simple to 10 extremely complicated), the user friendliness of the video Magill pliers was judged to be significantly higher than the standard Magill pliers (2.8 ± 1.6 vs. 7.8 ± 2.7 kindergarten teachers, 2.0 ± 1.3 vs. 7.2 ± 2.5 pupils and 3.2 ± 2.2 vs. 4.9 ± 3.1 prospective emergency physicians, p < 0.0001). Visibility of the airway foreign body was estimated to be significantly better employing the video Magill pliers compared to the standard Magill pliers (1.9 ± 1.4 vs. 9.8 ± 0.6 kindergarten teachers, pupils 1.3 ± 0.6 vs. 9.2 ± 1.6, prospective emergency physicians 2.3 ± 1.8 vs. 9.1 ± 2.3, p < 0.0001).

CONCLUSION

In this study kindergarten teachers, pupils (aged 10-14 years) and prospective emergency physicians had higher success rates in less time and reported better user friendliness and visibility using video Magill pliers compared to standard Magill pliers for removing a simulated foreign body from a CPR manikin airway.

[Automatic load-distributing band CPR (AutoPulse™) in prone position, feasible?]

BACKGROUND

Due to SARS-CoV‑2 respiratory failure, prone positioning of patients with respiratory and hemodynamic instability has become a frequent intervention in intensive care units (ICUs), and even in patients undergoing transfer in an ambulance or helicopter. It has become increasingly important how to perform safe and effective CPR in prone position, achieving both an optimal outcome for the patient and optimal protection of staff from infection.

MATERIALS AND METHODS

We conducted feasibility tests to assess the effects of CPR with an automatic load-distributing band (AutoPulse™) in prone position and discussed different aspects of mechanical chest compression (mCPR) in prone position.

RESULTS

In supine position, AutoPulse™ generated a constant pressure depth of 3cm at a frequency of 84/min. In prone position, AutoPulse™ generated a constant pressure depth of 2.6cm at a frequency of 84/min.

CONCLUSION

We found mCPR to be feasible in manikins in both prone and supine positions.

Mechanical chest compression devices in the helicopter emergency medical service in Switzerland

BACKGROUND

Over the past years, several emergency medical service providers have introduced mechanical chest compression devices (MCDs) in their protocols for cardiopulmonary resuscitation (CPR). Especially in helicopter emergency medical systems (HEMS), which have limitations regarding loading weight and space and typically operate in rural and remote areas, whether MCDs have benefits for patients is still unknown. The aim of this study was to evaluate the use of MCDs in a large Swiss HEMS system.

MATERIALS AND METHODS

We conducted a retrospective observational study of all HEMS missions of Swiss Air rescue Rega between January 2014 and June 2016 with the use of an MCD (Autopulse®). Details of MCD use and patient outcome are reported from the medical operation journals and the hospitals' discharge letters.

RESULTS

MCDs were used in 626 HEMS missions, and 590 patients (94%) could be included. 478 (81%) were primary missions and 112 (19%) were interhospital transfers. Forty-nine of the patients in primary missions were loaded under ongoing CPR with MCDs. Of the patients loaded after return of spontaneous circulation (ROSC), 20 (7%) experienced a second CA during the flight. In interhospital transfers, 102 (91%) only needed standby use of the MCD. Five (5%) patients were loaded into the helicopter with ongoing CPR. Five (5%) patients went into CA during flight and the MCD had to be activated. A shockable cardiac arrhythmia was the only factor significantly associated with better survival in resuscitation missions using MCD (OR 0.176, 95% confidence interval 0.084 to 0.372, p < 0.001).

CONCLUSION

We conclude that equipping HEMS with MCDs may be beneficial, with non-trauma patients potentially benefitting more than trauma patients.

[Terrorist attack training exercise-What can be learned? : Baden-Württemberg counterterrorism exercise (BWTEX)]

BACKGROUND

There is a risk of terror attacks in the Federal Republic of Germany, which might increase in the future. A timely comprehensive strategy for treatment and care of a large number of casualties helps minimize chaos and improve the outcome of patients. Adequate training is vital for successful implementation of an emergency plan. Therefore, the effectiveness of training should be assessed and evaluated; however, data collection capabilities for training events are extremely limited, so that publications on the topic are almost impossible to find.

OBJECTIVE

This study aimed to collect data from a simulated terrorist attack in order to draw conclusions from a clinical point of view concerning the improvement of preclinical and clinical management, taking interface problems into consideration.

MATERIAL AND METHODS

On 19 October 2019 the Ministry of the Interior, Digitalization and Migration of Baden-Württemberg conducted a large-scale simulation of a terrorist attack in the city center of Constance, called the Baden-Württemberg counterterrorism exercise (BWTEX). The simulation included an explosion of a car bomb as well as the use of firearms by terrorists. The large scale of the simulation with the high number of participants in combination with close cooperation between military and civil forces was unprecedented. The police force, the armed forces, civil protection forces, air rescue teams and staff from Constance, Friedrichshafen and Sigmaringen regional hospitals in southwest Germany worked together to treat simulated injuries to victims of the attack. The following parameters were recorded when the injured patients arrived at the hospital: prehospital triage time, prehospital triage score, initial treatment and quality of documentation on site as well as triage time, triage score, injury severity scale (ISS) score based on the specified injury pattern, treatment, and quality of documentation on hospital arrival.

RESULTS

Out of a total of 84 "injured patients" 55 were admitted to hospital and 80% were triaged at the scene. Injured patients of triage category 1 (TK1 red: life-threatening injury, immediate treatment) arrived at the hospital 198 ± 50 min after the attack, injured patients of triage category 2 (TK2 yellow: severely injured, urgent treatment) after 131 ± 44 min and injured patients of triage category 3 (TK3 green: slightly injured, non-urgent treatment) arrived after 157 ± 46 min. There was no significant difference in terms of arrival time at the hospital between the triage scores (r = 0.2) or between the ISS scores (r = 0.43). The authors assume that approximately 44% of TK1 patients would have died due to avoidable time delays. Prehospital medical documentation was insufficient in 78% and insufficient in 65% in the hospitals.

CONCLUSION

A mass casualty incident resulting from a terrorist attack differs greatly from a conventional mass casualty incident. The scene of the attack has to be evacuated as quickly as possible, which means that a large number of patients arrive untreated at the nearest hospitals. The setting up of treatment facilities in city centers and areas close to the city seems to be counterproductive because the time delay may result in higher mortality rates of victims. The particularities of mass casualties caused by a terrorist attack have to be incorporated into terrorist attack training.

[Publications by university Departments of Anaesthesiology from Germany, Austria and Switzerland in 2011-2015 : Scientific publications by university hospitals in D‑A-CH]

BACKGROUND

This study presents a count of publications and citations for all articles published by university Departments of Anaesthesiology in Germany, Austria and Switzerland between 2011 and 2015. The results were compared with former analyses of these countries from 2001-2010 as well as similar international studies.

METHODS

We performed a PubMed search based on PERL-scripts for all publications originating from university Departments of Anaesthesiology in Germany, Austria and Switzerland between 2011 and 2015. According to their author's affiliation, articles were assigned to their affiliated university department. Publications were considered an original article if the category of publication was classified as original research in PubMed. Predatory journals were omitted by using PubMed-listed journals only. Data of citations was retrieved from Thomson Reuter's ISI Web of Knowledge. The following indicators were reported: the number of publications and original articles (counting each author and first authors only) and the share of original articles out of all publications. With regard to citations, we reported the overall number, the percentage of publications, which were cited at least once and the median of citations per publication and per original article as well as the calculated h-index.

RESULTS

The 47 university Departments of Anaesthesiology published 4.697 articles between 2011 and 2015, which make up 89% of all anaesthesiology research originating from Germany, Austria and Switzerland (overall 5.284 publications). Of these, 1.037 (22%) were classified as original articles. Considering only articles with first authors, equalizing a change of PubMed's affiliation field policy in 2012 to compare the numbers with previous periods, 3.709 publications and 821 original articles were published. 90% of all publications and 96% of original articles, respectively, were cited at least once. Publications were cited six times, while original articles were cited nine times. The university department of Anaesthesiology in Zurich published most (n = 245), while most original articles were published in Vienna (n = 77). The highest share of original articles was achieved by Vienna (37%). Publications from Berlin - Benjamin Franklin and Jena (11 citations per publication) and original articles from Essen (23,5 citations per original article) achieved the highest citation rates.

DISCUSSION

In contrast to the worldwide increasing trend, the number of publications of the university Departments of Anaesthesiology in Germany, Austria and Switzerland stagnated. The share of original articles out of all publications continues to decline in comparison to 2001-2010 (-6%). Despite this, original articles were cited more frequently and thus had a higher value for the scientific community. The reasons of the decrease in the number of original articles remain unclear and require further investigation to reverse this negative trend.

CONCLUSION

Strategies to foster academic work in anaesthesiology in Germany, Austria and Switzerland are required.

The ProSeal Laryngeal Mask Airway in Prone Patients: A Retrospective Audit of 245 Patients

The use of the classic laryngeal mask airway (classic LMA) in the prone position is controversial, but the ProSeal laryngeal mask airway (ProSeal LMA) maybe more suitable as it forms a better seal and provides access to the stomach. In the following retrospective audit, we describe our experience with the insertion of, and maintenance of anaesthesia with, the ProSeal LMA in 245 healthy adults in the prone position by experienced users. The technique involved (1) the patient adopting the prone position with the head to the side and the table tilted laterally; (2) preoxygenation to end-tidal oxygen >90%; (3) induction of anaesthesia with midazolam/alfentanil/propofol; (4) facemask ventilation (5) a single attempt at digital insertion and if unsuccessful a single attempt at laryngoscope-guided, gum elastic bougie-guided insertion; (6) gastric tube insertion; (7) maintenance of anaesthesia with sevoflurane/O2/N2O; (8) volume controlled ventilation at 8-12 ml/kg; (9) emergence from anaesthesia in the supine position; and (10) removal of the ProSeal LMA when awake. Facemask ventilation was always successful. ProSeal LMA insertion was successful in all patients: 237 with digital insertion and eight with bougie-guided insertion. Ventilation was successful in all patients. Gastric tube insertion was successful in all patients. Correctable partial airway obstruction occurred in three patients, but there was no hypoxia, hypercapnoea, displacement, regurgitation, gastric insufflation or airway reflex activation. Our findings suggest that the insertion of and maintenance of anaesthesia with the ProSeal LMA is feasible in the prone position by experienced users.

2015 Revised Utstein-Style Recommended Guidelines for Uniform Reporting of Data From Drowning-Related Resuscitation: An ILCOR Advisory Statement

BACKGROUND

Utstein-style guidelines use an established consensus process, endorsed by the international resuscitation community, to facilitate and structure resuscitation research and publication. The first "Guidelines for Uniform Reporting of Data From Drowning" were published over a decade ago. During the intervening years, resuscitation science has advanced considerably, thus making revision of the guidelines timely. In particular, measurement of cardiopulmonary resuscitation elements and neurological outcomes reporting have advanced substantially. The purpose of this report is to provide updated guidelines for reporting data from studies of resuscitation from drowning.

METHODS

An international group with scientific expertise in the fields of drowning research, resuscitation research, emergency medical services, public health, and development of guidelines met in Potsdam, Germany, to determine the data that should be reported in scientific articles on the subject of resuscitation from drowning. At the Utstein-style meeting, participants discussed data elements in detail, defined the data, determined data priority, and decided how data should be reported, including scoring methods and category details.

RESULTS

The template for reporting data from drowning research was revised extensively, with new emphasis on measurement of quality of resuscitation, neurological outcomes, and deletion of data that have proved to be less relevant or difficult to capture.

CONCLUSIONS

The report describes the consensus process, rationale for selecting data elements to be reported, definitions and priority of data, and scoring methods. These guidelines are intended to improve the clarity of scientific communication and the comparability of scientific investigations.

CIS (change impact score) - a novel outcome measurement tool to quantify the relevance of medical education interventions on professional performance

Outcome measurements play a key role in professional CME (Continuing Medical Education). While assessment of delegate satisfaction and knowledge transfer is a common standard, it appears desirable to address higher levels of evidence. However, measurement of competence and performance is considered complex, difficult and expensive. The CIS (Change Impact Score) is a novel instrument to predict the relevance of the educational intervention to the professional performance of the physician, based on a standardised on-site self-assessment.

Safer employment of nitrous oxide in anesthesia machines—a technical simulation

Several incidents of anesthesia-attributed mortality in the past were caused by misconnection of gas pipelines resulting in ventilation with pure nitrous oxide. A simple safety feature may be to “mark” nitrous oxide with a lower pressure than oxygen and room air within the hospital's gas pipeline system. Then, any misconnection of gas pipelines could be detected by pressure differences with a manometer in the anesthesia machine. To check technical suitability, we tested maximum achievable nitrous oxide flows of an anesthesia machine at different pressures in the nitrous oxide supply line. Using decreased pressures for nitrous oxide compared to oxygen did not result in decreased nitrous oxide flows, as long as pressure in the nitrous oxide supply line was >1500 hPa. A concept of different pressures for nitrous oxide and oxygen could be used to technically differentiate between those two gases, and to avoid potentially fatal misconnections.

A domestic porcine model for studying the effects of radiation on head and neck cancers

BACKGROUND

Radiation therapy (RT) of the head and neck region is often accompanied by serious side effects. Research in this area is needed to improve treatment outcomes and ameliorate therapy tolerance. Laboratory rodents are barely matching today's clinical standards in RT research. Yet domestic swine (Sus scrofa domestica) have previously proved suitable for various advanced tests in clinical research and training. We therefore investigated whether S. scrofa domestica is also appropriate for irradiation of the mandible.

STUDY DESIGN

A common scheme for irradiation treatment of S. scrofa domestica mandibles in a split-mouth design was acquired by applying computed tomography (CT) scanning under sedation. Basing on close anatomic resemblance, a standard treatment plan comprising 2 opposed irradiation fields could be accomplished.

RESULTS

RT was carried out in a clinical environment with 2 × 9 Gy. The resulting operating procedure facilitated complication-free sedation, transport, positioning, CT scanning, and effective irradiation.

CONCLUSION

Based on common standards applied for RT in humans, domestic pigs can be employed to progress RT clinical research. Due to their human-like anatomy, physiology, size, and weight, the swine model is expedient for advancing experimental RT of the head and neck area.

[Injuries to blood vessels near the heart caused by central venous catheters]

Injuries to blood vessels near the heart can quickly become life-threatening and include arterial injuries during central venous puncture, which can lead to hemorrhagic shock. We report 6 patients in whom injury to the subclavian artery and vein led to life-threatening complications. Central venous catheters are associated with a multitude of risks, such as venous thrombosis, air embolism, systemic or local infections, paresthesia, hemothorax, pneumothorax, and cervical hematoma, which are not always immediately discernible. The subclavian catheter is at a somewhat lower risk of catheter-associated sepsis and symptomatic venous thrombosis than approaches via the internal jugular and femoral veins. Indeed, access via the subclavian vein carries a substantial risk of pneumo- and hemothorax. Damage to the subclavian vein or artery can also occur during deliberate and inadvertent punctures and result in life-threatening complications. Therefore, careful consideration of the access route is required in relation to the patient and the clinical situation, to keep the incidence of complications as low as possible. For catheterization of the subclavian vein, puncture of the axillary vein in the infraclavicular fossa is a good alternative, because ultrasound imaging of the target vessel is easier than in the subclavian vein and the puncture can be performed much further from the lung.

Dark silicon management: an integrated and coordinated cross-layer approach

This paper presents an integrated and coordinated cross-layer sensing and optimization flow for distributed dark silicon management for tiled heterogeneous manycores under a critical temperature constraint. We target some of the key challenges in dark silicon for manycores, such as: directly focusing on power density/temperature instead of considering simple per-chip power constraints, considering tiled heterogeneous architectures with different types of cores and accelerators, handling the large volumes of raw sensor information, and maintaining scalability. Our solution is separated into three abstraction layers: a sensing layer (involving hardware monitors and pre-processing), a dark silicon layer (that derives thermally-safe mappings and voltage/frequency settings), and an agent layer (used for selecting the parallelism of applications and thread-to-core mapping based on alternatives/constraints from the dark silicon layer).

Anesthesia in swine : optimizing a laboratory model to optimize translational research

In order to extrapolate novel therapies from the bench to the bedside (translational research), animal experiments are scientifically necessary. Swine are popular laboratory animals as their cardiorespiratory physiology is very similar to humans. Every study has to be approved by the local and/or national animal ethical committees. As swine are extremely sensitive to stress the primary goal is therefore to provide a calm, stress-free environment in both housing and experimental facilities. Swine should be properly sedated for transport and normothermia needs to be ensured. It is recommended to commence anesthesia by injecting ketamine and propofol followed by endotracheal intubation during spontaneous breathing. After intubation, anesthesia maintenance is performed with morphine or piritramide, propofol and rocuronium and routine monitoring is applied analogue to a clinical operating theater for humans. Normothermia (38.5 °C) needs to be ensured. While surgical procedures can be readily extrapolated from a human operating theater to swine, non-anesthesiologist scientists may lose the animal rapidly due to airway management problems. Vascular access can be secured by cut-downs or ultrasound-guided techniques in the inguinal and the neck region. For humane euthanasia of pigs, morphine, followed by propofol, rocuronium and potassium chloride are recommended. As radical animal right groups may threaten scientists, it is prudent that animal laboratories have unmarked entrance doors, are located in buildings that are not accessible to the public and strictly controlled access of laboratory staff is enforced. In conclusion, swine are an excellent laboratory animal for bench to bedside research and can be managed properly when basic knowledge and adequate skills on careful handling, anesthesia and surgical considerations are present.

[Drowning versus cardiac ischemia: Cardiac arrest of an 11-year-old boy at a swimming lake]

This report describes a case of sudden cardiac arrest and subsequent attempted cardiopulmonary resuscitation of an 11-year-old child on the shores of a swimming lake. Reports of eyewitnesses excluded the obviously suspected diagnosis of a drowning accident. The result of the autopsy was sudden cardiac death due to a congenital coronary anomaly (abnormal left coronary artery, ALCA). Favored by vigorous physical activity, this anomaly can lead to malignant arrhythmias because the ectopic coronary artery with its intramural course through the aortic wall is compressed during every systole. This pathology was not known to the boy or his family; in fact he liked sports but had suffered of a syncope once which was not followed up. Without a strong suspicion it is difficult to diagnose a coronary artery anomaly and it is often missed even in college athletes. Tragically, sudden cardiac arrest may be the first symptom of an undiagnosed abnormal coronary artery. Following syncope or chest pain during exercise with a normal electrocardiogram (ECG) cardiac imaging, such as computed tomography (CT) or angiography should be initiated in order to enable surgical repair of an abnormal coronary artery.

A dual-use laryngoscope to facilitate apneic oxygenation

BACKGROUND

In preoxygenated patients, time until oxygen saturation drops can be extended by insufflating oxygen into their airways, thus oxygenating them apneically.

OBJECTIVES

To compare different methods of apneic oxygenation.

METHODS

A noncommercial dual-use laryngoscope with an internal lumen in its blade was used to provide oxygen insufflation into a simulated laryngeal space during intubation. In this experimental study, oxygen insufflation via the dual-use laryngoscope was compared with no oxygen insufflation, with nasal oxygen insufflation, and with direct intratracheal oxygen insufflation. In a preoxygenated test lung of a manikin, oxygen percentage decrease was measured over a 20-min observation period for each method of oxygen application.

RESULTS

Oxygen percentage in the test lung dropped from 97% to 37 ± 1% in the control group (p < 0.001 compared to all other groups) and to 68 ± 1% in the nasal insufflation group (p < 0.001 compared to all other groups). Oxygen percentage remained over 90% in both the direct intratracheal insufflation group (96 ± 0%) and the laryngoscope blade insufflation group (94 ± 1%) (p < 0.01 between the latter two groups).

CONCLUSIONS

Simulating apneic oxygenation in a preoxygenated manikin, deep laryngeal oxygen insufflation via the dual-use laryngoscope kept oxygen percentage in the test lung above 90%, and was more effective than oxygen insufflation via nasal prongs.

[Modified McPeek score in multiple trauma patients. Prospective evaluation of a points system for recording follow-up factors]

BACKGROUND

Many commonly available trauma scores predict mortality, but to evaluate the success of a certain therapy or for difficult scientific and epidemiological purposes this may be insufficient in the face of improved survival rates. For outcome analysis of multiple trauma patients, the extent of medical resources needed could be an additional outcome measurement. McPeek et al. developed a potential scoring system for elective surgery patients, which was recently modified for multiple trauma patients.

AIM

The current study investigated if the McPeek score could be prospectively used in multiple trauma patients and whether it could become an additional helpful tool in outcome assessment. Applicability was assessed by practical examples.

MATERIAL AND METHODS

In this prospective single-centre study at the University Hospital of Innsbruck, Austria, between December 2008 and November 2010 multiple trauma patients (≥ 18 years) with an injury severity score (ISS) ≥ 17 were enrolled. Besides demographic data, prehospital vital parameters and diagnoses, all diagnoses from the trauma, mortality, length of stay in the intensive care unit and the hospital were recorded. The commonly used trauma scores ISS, revised trauma score (RTS), a severity characterization of trauma (ASCOT) and trauma and injury severity score (TRISS) were applied and an observed McPeek score was allocated following end of hospitalization. The McPeek scoring system was used according to the latest modifications. A correlation between trauma scores and the McPeek score was performed. The McPeek score was then predicted by a common trauma score using ordinal regression with the polytomous universal model (PLUM method). By subtracting the predicted from the observed McPeek scores the residual McPeek value was calculated and used for practical examples of outcome analysis with the McPeek scoring system.

RESULTS

Out of 406 identified multiple trauma patients during the study phase, 183 had to be excluded due to missing data (mainly prehospital or following transfer). A total of 223 patients (mean ISS 31.2, mean age 47.2 years) were enrolled and assigned to the population-based observed McPeek score (median 4.0). Correlation coefficients were Glasgow coma scale (GCS) 0.59, ISS 0.62, RTS 0.65, TRISS 0.74 and ASCOT 0.77 (p < 0.0001). The TRISS predicted the McPeek score best in ordinal regression (pseudo-R(2) = 0.944, p < 0.0001). The residual McPeek score (observed minus predicted) was used to illustrate the influence of the blood glucose level on admission and the influence of head injury on outcome of multiple injury patients in detail.

CONCLUSION

The modified McPeek score is applicable to multiple trauma patients to assess outcome for scientific or epidemiological purposes. Its main advantage is that it quantifies outcome independently of regional or national circumstances.

[Publication performances of university clinics for anesthesiology: Germany, Austria and Switzerland from 2001 to 2010]

AIM

This study assessed the publication performance of university departments of anesthesiology in Austria, Germany and Switzerland. The number of publications, original articles, impact factors and citations were evaluated.

MATERIAL AND METHODS

A search was performed in PubMed to identify publications related to anesthesiology from 2001 to 2010. All articles from anesthesiology journals listed in the fields of anesthesia/pain therapy, critical care and emergency medicine by the "journal citation report 2013" in Thomson Reuters ISI web of knowledge were included. Articles from non-anaesthesiology journals, where the stem of the word anesthesia (anes*, anaes*, anäst*, anast*) appears in the affiliation field of PubMed, were included as well. The time periods 2001-2005 and 2006-2010 were compared. Articles were allocated to university departments in Austria, Germany and Switzerland via the affiliation field.

RESULTS

A total of 45 university departments in Austria, Germany and Switzerland and 125,979 publications from 2,863 journals (65 anesthesiology journals, 2,798 non-anesthesiology journals) were analyzed. Of the publications 23 % could not be allocated to a given university department of anesthesiology. In the observation period the university department of anesthesiology in Berlin achieved most publications (n = 479) and impact points (1,384), whereas Vienna accumulated most original articles (n = 156). Austria had the most publications per million inhabitants in 2006-2010 (n=50) followed by Switzerland (n=49) and Germany (n=35). The number of publications during the observation period decreased in Germany (0.5 %), Austria (7 %) and Switzerland (8 %). Tables 2 and 4-8 of this article are available at Springer Link under Supplemental.

CONCLUSIONS

The research performance varied among the university departments of anesthesiology in Germany, Austria and Switzerland whereby larger university departments, such as Berlin or Vienna published most. Publication output in Germany, Austria and Switzerland has decreased. Data processing in PubMed should be improved.