Use of bitemporal NACA score documentation in prehospital emergency medical services- a retrospective study

BACKGROUND

The assessment of illness severity in the prehospital setting is essential for guiding appropriate medical interventions. The National Advisory Committee for Aeronautics (NACA) score is a validated tool commonly used for this purpose. However, the potential benefits of using bitemporal documentation of NACA scores to capture the dynamic changes in emergency situations remain uncertain. The objective of this study was to evaluate the potential benefit of bitemporal NACA score documentation in the prehospital setting, specifically in assessing the dynamic changes of emergencies and facilitating quality improvement through enhanced documentation practices.

METHODS

In this retrospective study, data from prehospital emergency patients were analyzed who received care from the physician response unit between January 1, 2018, and May 31, 2021. Patient demographics, NACA scores, indications for emergency care, and changes in NACA scores were extracted from medical records. Statistical analyses were performed to examine the associations between NACA scores, emergency categories, indications, and changes in NACA scores.

RESULTS

The study included 4005 patients, predominantly categorized as NACA III (33.7% at initial assessment, 41.8% at subsequent assessment) and NACA IV (31.6% at initial assessment, 22.4% at subsequent assessment). There was a significant improvement in NACA scores during the provision of prehospital care (p < 0.01). Notably, prehospital emergencies attributed to internal medical, neurological, traumatic, and paediatric causes demonstrated significant improvements in NACA scores (p < 0.01). Gender-specific differences were also observed.

CONCLUSION

Our study suggests that the bitemporal documentation of NACA scores can be advantageous in the prehospital setting and may have implications for research, practice, and policy.

Physician utilization in prehospital emergency medical services in Europe: an overview and comparison

OBJECTIVES

National and regional systems for emergency medical care provision may differ greatly. We sought to determine whether or not physicians are utilized in prehospital care and to what extent they are present in differentEuropean countries.

MATERIAL AND METHODS

We collected information on 32 European countries by reviewing publications and sending questionnaires to authors of relevant articles as well as to officials of ministries of health (or equivalent), representatives of national societies in emergency medicine, or well-known experts in the specialty.

RESULTS

Thirty of the 32 of European countries we studied (94%) employ physicians in prehospital emergency medical services. In 17 of the 32 (53%), general practitioners also participate in prehospital emergency care. Emergency system models were described as Franco-German in 27 countries (84%), as hybrid in 17 (53%), and as Anglo-American in 14 (44%). Multiple models were present simultaneously in 17 countries (53%). We were able to differentiate between national prehospital emergency systems with a novel classification based on tiers reflecting the degree of physician utilization in the countries. We also grouped the national systems by average population and area served.

CONCLUSION

There are notable differences in system designs and intensity of physician utilization between different geographic areas, countries, and regions in Europe. Several archetypal models (Franco-German, hybrid, and Anglo- American) exist simultaneously across Europe.

Mechanical ventilation with ten versus twenty breaths per minute during cardio-pulmonary resuscitation for out-of-hospital cardiac arrest: A randomised controlled trial

AIM OF THE STUDY

This study sought to assess the effects of increasing the ventilatory rate from 10 min^-1 to 20 min^-1 using a mechanical ventilator during cardio-pulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) on ventilation, acid-base-status, and outcomes.

METHODS

This was a randomised, controlled, single-centre trial in adult patients receiving CPR including advanced airway management and mechanical ventilation offered by staff of a prehospital physician response unit (PRU). Ventilation was conducted using a turbine-driven ventilator (volume-controlled ventilation, tidal volume 6 ml per kg of ideal body weight, positive end-expiratory pressure (PEEP) 0 mmHg, inspiratory oxygen fraction (FiO₂) 100%), frequency was pre-set at either 10 or 20 breaths per minute according to week of randomisation. If possible, an arterial line was placed and blood gas analysis was performed.

RESULTS

The study was terminated early due to slow recruitment. 46 patients (23 per group) were included. Patients in the 20 min^-1 group received higher expiratory minute volumes [8.8 (6.8-9.9) vs. 4.9 (4.2-5.7) litres, p < 0.001] without higher mean airway pressures [11.6 (9.8-13.6) vs. 9.8 (8.5-12.0) mmHg, p = 0.496] or peak airway pressures [42.5 (36.5-45.9) vs. 41.4 (32.2-51.7) mmHg, p = 0.895]. Rates of ROSC [12 of 23 (52%) vs. 11 of 23 (48%), p = 0.768], median pH [6.83 (6.65-7.05) vs. 6.89 (6.80-6.97), p = 0.913], and median pCO₂ [78 (51-105) vs. 86 (73-107) mmHg, p > 0.999] did not differ between groups.

CONCLUSION

20 instead of 10 mechanical ventilations during CPR increase ventilation volumes per minute, but do not improve CO₂ washout, acidaemia, oxygenation, or rate of ROSC.

CLINICALTRIALS

gov Identifier: NCT04657393.

Assessing the weak links - Necessity and impact of regional cardiac arrest awareness campaigns for laypersons

Introduction

Public knowledge of out-of-hospital cardiac arrest (OHCA), and initiation of basic life support (BLS) is crucial to increase survival in OHCA.

Methods

The study analysed the knowledge and willingness to perform BLS of laypersons passing an AED at a public train station. Interviewees were recruited at two time points before and after a four year-long structured regional awareness campaign, which focused on call, compress, shock in a mid-size European city (270,000 inhabitants). Complete BLS was defined as multiple responses for call for help; initiation of chest compressions; and usage of an AED, without mentioning recovery position. Minimal BLS was defined as call for help and initiation of chest compressions.

Results

A total of 784 persons were interviewed, 257 at baseline and 527 post-campaign. Confronted with a fictional OHCA, at baseline 8.5% of the interviewees spontaneously mentioned actions for complete BLS and 17.9% post-campaign (p = 0.009). An even larger increase in knowledge was seen in minimal BLS (34.6% vs 60.6%, p < 0.001).

Conclusion

After a regional cardiac arrest awareness campaign, we found an increase in knowledge of BLS actions in the lay public. However, our investigation revealed severe gaps in BLS knowledge, possibly resulting in weak first links of the chain of survival.

Reliability of mechanical ventilation during continuous chest compressions: a crossover study of transport ventilators in a human cadaver model of CPR

Background

Previous studies have stated that hyperventilation often occurs in cardiopulmonary resuscitation (CPR) mainly due to excessive ventilation frequencies, especially when a manual valve bag is used. Transport ventilators may provide mandatory ventilation with predetermined tidal volumes and without the risk of hyperventilation. Nonetheless, interactions between chest compressions and ventilations are likely to occur. We investigated whether transport ventilators can provide adequate alveolar ventilation during continuous chest compression in adult CPR.

Methods

A three-period crossover study with three common transport ventilators in a cadaver model of CPR was carried out. The three ventilators ‘MEDUMAT Standard²’, ‘Oxylog 3000 plus’, and ‘Monnal T60’ represent three different interventions, providing volume-controlled continuous mandatory ventilation (VC-CMV) via an endotracheal tube with a tidal volume of 6 mL/kg predicted body weight. Proximal airflow was measured, and the net tidal volume was derived for each respiratory cycle. The deviation from the predetermined tidal volume was calculated and analysed. Several mixed linear models were calculated with the cadaver as a random factor and ventilator, height, sex, crossover period and incremental number of each ventilation within the period as covariates to evaluate differences between ventilators.

Results

Overall median deviation of net tidal volume from predetermined tidal volume was − 21.2 % (IQR: 19.6, range: [− 87.9 %; 25.8 %]) corresponding to a tidal volume of 4.75 mL/kg predicted body weight (IQR: 1.2, range: [0.7; 7.6]). In a mixed linear model, the ventilator model, the crossover period, and the cadaver’s height were significant factors for decreased tidal volume. The estimated effects of tidal volume deviation for each ventilator were − 14.5 % [95 %-CI: −22.5; −6.5] (p = 0.0004) for ‘Monnal T60’, − 30.6 % [95 %-CI: −38.6; −22.6] (p < 0.0001) for ‘Oxylog 3000 plus’ and − 31.0 % [95 %-CI: −38.9; −23.0] (p < 0.0001) for ‘MEDUMAT Standard²’.

Conclusions

All investigated transport ventilators were able to provide alveolar ventilation even though chest compressions considerably decreased tidal volumes. Our results support the concept of using ventilators to avoid excessive ventilatory rates in CPR. This experimental study suggests that healthcare professionals should carefully monitor actual tidal volumes to recognise the occurrence of hypoventilation during continuous chest compressions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00921-2.

[System and skill utilization in an Austrian emergency physician system: retrospective study]

BACKGROUND

The continuous rise in calls for emergency physicians and the low proportion of indicated missions has led to a loss of job attractiveness, which in turn renders services in some areas unable to sufficiently staff units. This retrospective analysis evaluated the frequency of emergency and general medical interventions in a ground-based emergency physician response system.

METHODS

A retrospective analysis of anonymized data from the electronic documentation system of the emergency physician response unit at the Medical University of Graz was carried out. Calls answered by emergency physicians between 2010 and 2018 were extracted, measures carried out were evaluated and categorized into three groups: specific emergency interventions (category I), general medical interventions (category II) and no medical activity (category III). The frequency of occurrence of these categories was compared and incidences of individual measures per 100,000 inhabitants were calculated.

RESULTS

A total of 15,409 primary responses and 322 secondary transports were extracted and analyzed. The annual rate of system activation rose almost continuously from 1442 calls in 2010 to 2301 calls in 2018. The 3687 (23.4%) cancellations resulted in 12,044 patient contacts. Of these, 2842 (18%) calls were coded as category I, 7372 (47%) as category II and 5518 (35%) as category III. The frequency of specific emergency measures and general medical interventions was estimated at 157/100,000 and 409/100,000 inhabitants, respectively.

CONCLUSIONS

No specific emergency physician interventions were required in the majority of call-outs. The current model of preclinical care does not appear to be patient-oriented and efficient. Furthermore, the low proportion of critically ill and injured patients already leads to a reduction in attractiveness for emergency physicians and may introduce the threat of quality issues due to insufficient routine experience and lack of training.

Atlanto-occipital dislocation in a patient presenting with out-of-hospital cardiac arrest: a case report and literature review

Background

Atlanto-occipital dislocation is a rare and severe injury of the upper spine associated with a very poor prognosis.

Case presentation

We report the case of a 59-year-old European man who suffered from out-of-hospital cardiac arrest following a motor vehicle accident. Cardiopulmonary resuscitation was initiated immediately by bystanders and continued by emergency medical services. After 30 minutes of cardiopulmonary resuscitation with a total of five shocks following initial ventricular fibrillation, return of spontaneous circulation was achieved. An electrocardiogram recorded after return of spontaneous circulation at the scene showed signs of myocardial ischemia as a possible cause for the cardiac arrest. No visible signs of injury were found. He was transferred to the regional academic trauma center.

Following an extended diagnostic and therapeutic workup in the emergency room, including extended focused assessment with sonography for trauma ultrasound, whole-body computed tomography, and magnetic resonance imaging (of his head and neck), a diagnosis of major trauma (atlanto-occipital dislocation, bilateral serial rip fractures and pneumothoraces, several severe intracranial bleedings, and other injuries) was made. An unfavorable outcome was initially expected due to suspected tetraplegia and his inability to breathe following atlanto-occipital dislocation.

Contrary to initial prognostication, after 22 days of intensive care treatment and four surgical interventions (halo fixation, tracheostomy, intracranial pressure probe, chest drains) he was awake and oriented, spontaneously breathing, and moving his arms and legs. Six weeks after the event he was able to walk without aid. After 2 months of clinical treatment he was able to manage all the activities of daily life on his own.

It remains unclear, whether cardiac arrest due to a cardiac cause resulted in complete atony of the paravertebral muscles and caused this extremely severe lesion (atlanto-occipital dislocation) or whether cardiac arrest was caused by apnea due the paraplegia following the spinal injury of the trauma.

Conclusions

A plausible cause for the trauma was myocardial infarction which led to the car accident and the major trauma in relation to the obviously minor trauma mechanism. With this case report we aim to familiarize clinicians with the mechanism of injury that will assist in the diagnosis of atlanto-occipital dislocation. Furthermore, we seek to emphasize that patients presenting with electrocardiographic signs of myocardial ischemia after high-energy trauma should primarily be transported to a trauma facility in a percutaneous coronary intervention-capable center rather than the catheterization laboratory directly.

Arterial blood gases during and their dynamic changes after cardiopulmonary resuscitation: A prospective clinical study

PURPOSE

An arterial blood gas analysis (ABG) yields important diagnostic information in the management of cardiac arrest. This study evaluated ABG samples obtained during out-of-hospital cardiopulmonary resuscitation (OHCPR) in the setting of a prospective multicenter trial. We aimed to clarify prospectively the ABG characteristics during OHCPR, potential prognostic parameters and the ABG dynamics after return of spontaneous circulation (ROSC).

METHODS

ABG samples were collected and instantly processed either under ongoing OHCPR performed according to current advanced life support guidelines or immediately after ROSC and data ware entered into a case report form along with standard CPR parameters.

RESULTS

During a 22-month observation period, 115 patients had an ABG analysis during OHCPR. In samples obtained under ongoing CPR, an acidosis was present in 98% of all cases, but was mostly of mixed hypercapnic and metabolic origin. Hypocapnia was present in only 6% of cases. There was a trend towards higher paO2 values in patients who reached sustained ROSC, and a multivariate regression analysis revealed age, initial rhythm, time from collapse to CPR initiation and the arterio-alveolar CO2 difference (AaDCO2) to be associated with sustained ROSC. ABG samples drawn immediately after ROSC demonstrated higher paO2 and unaltered pH and base excess levels compared with samples collected during ongoing CPR.

CONCLUSIONS

Our findings suggest that adequate ventilation and oxygenation deserve more research and clinical attention in the management of cardiac arrest and that oxygen uptake improves within minutes after ROSC. Hyperventilation resulting in arterial hypocapnia is not a major problem during OHCPR.

The Medizinercorps Graz: a 120-year-old institution of emergency medicine

One year after the establishment of the rescue service of Graz, Austria, in 1889, twelve young medical students were recruited because of the lack of accredited physicians for emergency care, leading to the foundation of the Medizinercorps Graz. This concept of involving medical students in prehospital emergency care has been retained for more than 120 years, and today the Medizinercorps is integrated into the local Red Cross branch, staffing two emergency ambulance vehicles. The responsible medical officer is called Rettungsmediziner and is an advanced medical student with a specialized emergency medical training of more than 3,000 hours, comprising theoretical lectures; in-hospital clerkships in anesthesia, internal medicine, and surgery; manikin training; and hands-on peer-to-peer teaching during assignments. The local emergency medical system provides at least 10 regular basic ambulance vehicles, the two emergency ambulance vehicles, and two emergency physicians on a 24-hours-a-day/seven-days-a-week basis for about 300,000 people. The emergency ambulance vehicles staffed with a Rettungsmediziner respond to all kinds of possibly life-threatening situations and also provide interhospital transfer of intensive care patients. This entirely volunteer-based system enables extremely high-level prehospital emergency care, saves resources and reduces costs, and employs modern training concepts for the continuing advancement of prehospital emergency care.

Cardiac movement identified on prehospital echocardiography predicts outcome in cardiac arrest patients

INTRODUCTION

The prognostic value of emergency echocardiography (EE) in the management of cardiac arrest patients has previously been studied in an in-hospital setting. These studies mainly included patients who underwent cardiopulmonary resuscitation (CPR) by emergency medicine technicians at the scene and who arrived at the emergency department (ED) still in a state of cardiac arrest. In most European countries, cardiac arrest patients are normally treated by physician-staffed emergency medical services (EMS) teams on scene. Transportation to the ED while undergoing CPR is uncommon.

OBJECTIVE

To evaluate the ability of EE to predict outcome in cardiac arrest patients when it is performed by ultrasound-inexperienced emergency physicians on scene.

METHODS

We performed a prospective, observational study of nonconsecutive, nontrauma, adult cardiac arrest patients who were treated by physician-staffed urban EMS teams on scene. Participating emergency physicians (EPs) received a two-hour course in EE during CPR. After initial procedures were accomplished, EE was performed during a rhythm and pulse check. A single subxiphoid, four-chamber view was required for study enrollment. We defined sonographic evidence of cardiac kinetic activity as any detected motion of the myocardium, ranging from visible ventricular fibrillation to coordinated ventricular contractions. The CPR had to be continued for at least 15 minutes after the initial echocardiography. No clinical decisions were made based on the results of EE.

RESULTS

Forty-two patients were enrolled in the study. The heart could be visualized successfully in all patients. Five (11.9%) patients survived to hospital admission. Of the 32 patients who had cardiac standstill on initial EE, only one (3.1%) survived to hospital admission, whereas four out of 10 (40%) patients with cardiac movement on initial EE survived to hospital admission (p = 0.008). Neither asystole on initial electrocardiogram nor peak capnography value, age, bystander CPR, or downtime was a significant predictor of survival. Only cardiac movement was associated with survival, and cardiac standstill at any time during CPR resulted in a positive predictive value of 97.1% for death at the scene.

CONCLUSION

Our results support the idea of focused echocardiography as an additional criterion in the evaluation of outcome in CPR patients and demonstrate its feasibility in the prehospital setting.

Prehospital lung ultrasound in the distinction between pulmonary edema and exacerbation of chronic obstructive pulmonary disease

We present 2 cases of dyspneic patients, where prehospital lung ultrasound helped to distinguish between pulmonary edema and acute exacerbation of chronic obstructive pulmonary disease.

Prehospital fiberoptic intubation

We present a case of a patient with severe multiple trauma who was treated at the scene by a physician-staffed trauma life support team. Due to a complete tracheal transection, a "cannot ventilate, cannot intubate"-situation occurred. The patient was then intubated using a fiberoptic bronchoscope in the prehospital setting. The current literature concerning fiberoptic intubation in emergencies is discussed.

Virtuelle hepatobiliäre Chirurgie - computerunterstützte Resektionsplanung an der dreidimensional rekonstruierten Leber

Recent developments in image-based computer assistance provide an improved visualisation of the intrahepatic vascular branching system in a virtual three-dimensional model of the liver, allowing a quantitative assessment of any vascular territory. The advantages of computer-assisted resection planning refer to a better preoperative assessment of functional resectability in areas at risk for either devascularisation or impaired drainage. In selected cases, this information may have a considerable influence on operative planning, especially with regard to the extent of resection or the need for vascular reconstruction. Due to the great anatomical variability of the intrahepatic branching patterns of the right liver lobe, this seems to be particularly important in extended left hepatectomies or in repeat hepatectomy when intrahepatic vascular anatomy may be altered. The development of navigation techniques to ensure the accurate application of the preoperative planned resection line is under investigation but not available yet.

Emergency treatment of chest trauma--an e-learning simulation model for undergraduate medical students

OBJECTIVE

Appropriate emergency measures are essential in improving the outcome of patients with thoracic injuries. Pathophysiological background and basic principles of emergency treatment decisions should be already taught in undergraduate medical curricula. The effectiveness of a computer simulation model on thoracic trauma management was evaluated.

METHODS

Forty-one students were enrolled in this pre-test/post-test self-controlled study. Learning experience was based on a complex computer simulation model demonstrating basic mechanisms of thoracic injuries and facilitating the interactive application of various emergency measures.

RESULTS

Pre-test multiple-choice results were 72.2% (66.9-77.5) correct answers, which increased significantly to 86.5% (82.6-90.4) in the post-test (p<0.001). The students spent 30 min (23-36) with the interactive learning object. Content analysis of open-ended feedback revealed a highly significant overall positive judgement (p<0.001), where the importance of 'trial and error' learning, the possibility of being able to 'view a process' and the simplicity of the model were particularly stressed.

CONCLUSIONS

Computer simulation of chest trauma emergency treatment options is a safe and efficient learning approach in undergraduate medical education, which is highly appreciated by the students.

Strategien zur Optimierung notärztlicher Kompetenz in der Flugrettung

PURPOSE

Preclinical emergency medical treatment necessitates a comprehensive interdisciplinary knowledge by the emergency physician as well as a high level of manual dexterity. The quality of treatment therefore depends on the level of education and continuous training in emergency medical techniques. Based on an evaluation of the frequency of life-saving interventions by a physician-staffed rescue helicopter system, strategies for in-hospital training of relevant skills are suggested.

MATERIAL AND METHODS

At the outset, 10 important areas of treatment (e.g. intubation, chest tube etc.) and their frequency in emergency medical services were defined as the standard to be attained by emergency physicians within 1 year. The selection of the areas of treatment was based to some extent on international recommendations. The actual frequencies of the prehospital interventions were compared to the required minimum numbers by retrospective analysis of the helicopter rescue database (NACA-X).

RESULTS

During the observation period of 1 year, 20 emergency physicians responded to 956 prehospital emergency calls. A life-threatening condition requiring an on-site intervention occurred in only 521 (54.5%) patients, so that the majority of physicians did not perform the required minimum number of interventions. In order to maintain their level of skill, the emergency physicians were required to undertake additional training at the local university hospital.

CONCLUSION

The frequency of on-site life-saving interventions in emergency medicine is insufficient to fulfill the quota necessary to maintain adequate training of emergency physicians. Only a link-up program at a hospital for primary care can ensure an adequate training level.

Arterial oxygen tension increase 2-3 h after hyperbaric oxygen therapy: a prospective observational study

BACKGROUND

Inhalation of hyperbaric oxygen (HBO) has been reported to decrease arterial oxygen tension (PaO(2)) in the early period after exposure. The current investigation aimed at evaluating whether and to what extent arterial blood gases were affected in mechanically ventilated intensive care patients within 6 h after HBO treatment.

METHODS

Arterial blood gases were measured in 11 ventilated subjects [nine males, two females, synchronized intermittent mandatory ventilation (SIMV) mode] undergoing HBO therapy for necrotizing soft tissue infection (seven patients), burn injury (two patients), crush injury (one patient) and major abdominal surgery (one patient). Blood gases were obtained with the patients in the supine position under continuous analgesia and sedation before the hyperbaric session (baseline), during isopression, after decompression, after each transport, and 1, 2, 3 and 6 h after exposure. Heart rates and blood pressures were recorded. Intensive care unit (ICU) ventilator settings remained unchanged. Transport and chamber ventilator settings were adjusted to baseline with maintenance of tidal volumes and positive end-expiratory pressure (PEEP) levels. The hyperbaric protocol consisted of 222.9 kPa (2.2 absolute atmospheres) and a 50-min isopression phase. The paired Wilcoxon's test was used.

RESULTS

Major findings (median values, 25%/75% quartiles) as per cent change of baseline: PaO(2) values decreased by 19.7% (7.0/31.7, P < 0.01) after 1 h and were elevated over baseline by 9.3% (1.5/13.7, P < 0.05) after 3 h. SaO(2), alveolar-arterial oxygen tension difference and PaO(2)/FiO(2) ratio behaved concomitantly. Acid-base status and carbon dioxide tension were unaffected.

CONCLUSION

Arterial oxygen tension declines transiently after HBO and subsequently improves over baseline in intensive care patients on volume-controlled mechanical ventilation. The effectiveness of other ventilation modes or a standardized recruitment manoeuvre has yet to be evaluated.

The acute coronary syndrome--pre-hospital diagnostic quality

BACKGROUND AND OBJECTIVE

In the Austrian emergency medical service (EMS), emergency medical technician-staffed and physician-staffed vehicles are in operation. Patients with suspected acute coronary syndromes (ACS) are treated in the pre-hospital phase and transported to the hospital by an emergency physician (EP). This study evaluates the diagnostic performance of EPs in ACS and the impact of this emergency system on the outcome of ACS in an urban area.

DESIGN

Retrospective case control study.

METHODS

All protocol sheets from the emergency physicians were searched for the diagnosis of ACS. The database of the emergency department (ED) was searched for patients with ACS as an admission diagnosis or ACS as discharge diagnosis. For patients admitted to an intensive care unit (ICU), the medical history from the ICU was reviewed. According to the diagnosis and the aggressiveness of therapy, patients were divided in five categories of severity at each stage of care (pre-hospital category, ED category, ICU category).

RESULTS

A total of 3585 patients was analysed. Only 17.8% of the patients with ACS as the admission diagnosis and 20.3% of the patients with ACS as the discharge diagnosis were transported by an EP. 46.8% of the ACS diagnosis by EPs were confirmed in hospital. Patients transported by EPs showed a higher all-cause mortality in hospital (1.6% vs. 0.6%; p=0.011). There was no significant correlation between the pre-hospital category of patients treated by EPs and the ED category. When a 12-lead-electrocardiogram was recorded, the correlation improved slightly (rho: 0.139; p=0.006).

CONCLUSIONS

The percentage of ACS patients transported to hospital by an EP is very low, and EPs seem to be "over-aware" in the diagnosis of ACS.

The influence of lunar phenomena on the incidence of emergency cases

It is widely believed that the incidence of specific emergency cases shows clustering during long observation periods. Though there is no scientific proof, many physicians and other emergency staff believe in influences of the moon or the signs of the zodiac. The aim of our retrospective study over 6 years was to evaluate (a) if there are any statistically documented peaks of frequency of emergency cases at all, and (b) if they can be linked to lunar phenomena. We evaluated all three aspects of the moon: The 'synodic' moon (=lunar phases), the 'sideric' moon (=distance between moon and the earth) and the moon in her relation to the signs of the zodiac (=influence of the zodiac). A total of 11134 patients entered the study. We found highly significant clusters of emergency calls, mainly for lung disorders. However, neither aspect of the moon showed the slightest correlation with the frequency of emergency calls (sideric month (P=0.99), synodic month (P=0.85) and zodiac (P=0.85)). Trigonometric regression with the period of the anomalistic month (P=0.173) and with the synodic month (P=0.28) did not show any influence of the moon on emergency in either cases. Though our retrospective data analysis documented clustering of emergency cases, any influence of the moon and the signs of the zodiac can be definitely ruled out.

Hemodynamic and oxygenation profiles in the early period after hyperbaric oxygen therapy: an observational study of intensive-care patients

BACKGROUND

We studied whether hemodynamic and oxygenation profiles are altered in critically ill patients after exposure to hyperbaric oxygen (HBO).

METHODS

Ten intensive-care patients (two females, eight males) undergoing HBO treatment after major abdominal surgery, after burn injury and after CO poisoning were included. All subjects were put on mechanical ventilation and received continuous sedation, and had HBO treatment at 2.2 absolute atmospheres for 50 min.

DESIGN

Observational prospective study, and repeated measure design.

RESULTS

Hemodynamic and oxygen transport patterns were determined before (C0), 1 h (C1) and 2 h (C2) after HBO therapy with continuous cardiac output dual oximetry pulmonary arterial catheter, a central venous and radial arterial line. Data were analyzed with non-parametric repeated measure analysis. Key results are expressed as a percentage of baseline (C0 values correspond to 100%) at C1 and C2 (median values, lower and upper limit of confidence interval): cardiac index [C1: 105% (98-135), C2: 99% (91-117), P = 0.19], systemic (P = 0.62) and pulmonary vascular (P = 0.76) resistance indices were unchanged, but pulmonary venous admixture (Qs/Qt) increased [C1: 173% (112-298), C2: 140% (92-241), P = 0.00002)] and arterial oxygen tension decreased [C1: 76% (67-94), C2: 82% (72-112), P = 0.010].

CONCLUSION

The hemodynamic profile remained unaffected. The increase in Qs/Qt and the decrease in PaO2 may be attributed to the inhalation of HBO, and both are reversible.

[Recommendations for prognostic assessment of cerebral hypoxia after cardiopulmonary resuscitation--Austrian Interdisciplinary Consensus Conference]

Various clinical parameters, neurological examination models, biochemical tests, electrophysiological procedures and neuro-imaging techniques have been studied with respect to the detection of cerebral hypoxia in patients after cardiopulmonary resuscitation. These parameters were critically evaluated by the members of the Austrian interdisciplinary consensus conference. Based on the results of scientific publications, the consensus meeting identified 26 parameters, which allow the prognostic evaluation of cerebral hypoxia after cardiopulmonary resuscitation. Among these parameters, however, the strength of evidence and the level of recommendation are different.

Comparison of lactate or BE during out-of-hospital cardiac arrest to determine metabolic acidosis

During cardiopulmonary resuscitation, pH and base excess (BE) decrease to a variable degree due to metabolic acidosis. The main cause has been shown to be lactate, which cannot be eliminated sufficiently because of low perfusion during cardiac massage. Both BE and lactate can be measured in the prehospital phase. The aim of the study was to determine if BE and lactate are comparable variables during cardiopulmonary resuscitation (CPR) and if the measurement of lactate level alone would be sufficient to determine the patient's metabolic status and sufficiently reliable to determine the administration of buffer solutions. During the observation period, we registered 31 patients (21 males, ten females) who were resuscitated according to European Resuscitation Council recommendations, who had blood gas analysis and lactate levels measured in blood taken by arterial puncture or arterial line. The first measurement from each patient was taken after primary resuscitation (within 5-20 min). The mean lactate level was 9.85+/-2.98 (range, 4.1-18.7) mmol/l, and the mean BE was -15.0+/-5.98 (range, 5.5 to -24.3). There were statistically significant correlations between the lactate level and BE and pH (linear correlation, r=-0.673, P<0,001 and r=-0,683, P<0,001, respectively), but not with pO2 and pCO2. The receiver-operated curve analysis showed that a cut-off point of 7.0 mmol/l lactate indicates a BE below -10 with a sensitivity of 96% and a specificity of 67%. Lactate measurement is a valuable tool to determine metabolic acidosis during CPR and may be able to replace blood gas analysis in this situation.

Differential lung ventilation and emergency hyperbaric oxygenation for repair of a tracheal tear

PURPOSE

To report the anaesthetic management of a case of tracheal rupture, using different types of ventilation and additional hyperbaric oxygenation (HBO).

CLINICAL FEATURES

An 8 cm postintubation tracheal tear was repaired in a 66-yr-old woman with acute myocardial reinfarction, mediastinal and subcutaneous emphysema, cardiac failure and unrecognized lymphoma. Intraoperative monitoring included dual oximetry: arterial (SaO2) and mixed venous saturations (SvO2). Maintenance of free surgical access and a series of life-threatening events like dislocation of the jet catheter required many ventilation modes. An episode of supraventricular tachycardia was interrupted by cardioversion. Differential lung ventilation with a combination of conventional and high-frequency jet ventilation (HFJV) modes preserved oxygenation (PO2 139.2 mm Hg, PCO2 42.4 mm Hg, FiO2 1.0) until acute tube obstruction and decrease of saturation values (SaO2 58%, SvO2 45%) required emergency HBO: immediate cardiac and respiratory stabilization was provided by double-lung HFJV and apneic oxygenation under hyperbaric conditions at 2.5 atmospheres absolute for 35 min (SaO2 100%). The patient recovered from surgery but died of non-Hodgkin lymphoma.

CONCLUSION

The combination of different ventilation modes including HFJV and the additional use of HBO resulted in sufficient oxygenation during tracheal repair.