["Topless" cardiopulmonary resuscitation. Fashion or science?]. / Kardiopulmonale Reanimation "oben ohne". Mode oder Wissenschaft?

A decade after the onset of a discussion whether ventilation could be omitted from bystander basic life support (BLS) algorithms, the state of the evidence is reevaluated. Initial animal studies and a prospective randomized patient trial had suggested that omission of ventilation during the first minutes of lay cardiopulmonary resuscitation (CPR) did not impair patient outcomes. More recent studies demonstrate, however, that this may hold true only in very specific scenarios, and that the chest compression-only technique was never superior to standard BLS. Instead of calling basics of BLS training and practice into question, more and better training of lay persons and professionals appears mandatory, and targeted use of dispatcher-guided telephone CPR should be evaluated and, if it improves outcome, it should be encouraged. Future studies should focus much less on the omission but on the optimization of ventilation under the specific conditions of CPR.

Artificial ventilation for basic life support leads to hyperventilation in first aid providers.

The 'Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - International Consensus on Science' recommend an artificial ventilation volume of 10 ml/kg bodyweight (equivalent to a tidal volume of 700-1000 ml) without the use of supplemental oxygen in adults with respiratory arrest. For first aid providers using the mouth-to-mouth or mouth-to-nose-ventilation technique, respectively, a ventilation volume of approximately 9.6 l/min results. Additionally, a deep breath is recommended before each ventilation to increase the end-expiratory oxygen concentration of the air exhaled by the first aid provider. To investigate the effects of these recommendations in healthy volunteers, test persons were asked to ventilate an artificial lung model for a period of up to 10 min. The tidal volume was set at 800 ml at a breathing rate of 12/min. End-tidal carbon dioxide, oxygen saturation (measured by pulse oximetry), and heart rate were measured continuously. Capillary blood gas samples were collected and non-invasive blood pressure readings were recorded prior to the start of ventilation and immediately after the end of the measuring period. The data reveal a statistically significant and clinically relevant decrease in end-tidal carbon dioxide pressure (P<0.001, median decrease 14 mmHg), and the occurrence of hyperventilation-associated symptoms such as paraesthesia, dizziness, and carpopedal spasms in more than 75% of the participants. Clinically and statistically significant hyperventilation results in first aid providers performing artificial ventilation according to the guidelines. This artificial ventilation is associated with a significant decrease in capillary and end-tidal carbon dioxide pressure as well as with multiple symptoms of an acute hyperventilation syndrome. Ventilation performed according to these guidelines may cause injury to the health of the first aid provider. Rescuers ventilating the victim should be replaced at regular intervals and the recommendation to take a deep breath before each ventilation should not be upheld in order to minimise the risk of hyperventilation.

The carotid pulse check revisited: what if there is no pulse?

This study was undertaken to evaluate the diagnostic accuracy and time required by first responders to assess the carotid pulse in potentially pulseless patients. We conducted a prospective, randomized study of first responders (n = 206; four different training levels) and were blinded as to the patients' conditions in the cardiac operating rooms of a university hospital. Sixteen patients underwent coronary artery bypass surgery on nonpulsatile cardiopulmonary bypasses. Carotid pulse check was performed either during pulsatile (spontaneous) or during nonpulsatile (extracorporeal) circulation. Patients' hemodynamic status at the time of assessment, diagnostic accuracy of the first responders, and the time required to diagnose carotid pulsatility or pulselessness were documented. Within 10 secs, only 16.5% of the participants (34 of 206) were able to reach any decision about their patients' pulse status. Assessments that were both rapid and correct (15%, i.e., 31 of 206) occurred almost exclusively in pulsatile patients. Advanced training level shortened the delay to decision and improved its accuracy. However, merely 2% of the participants (1 of 59) correctly recognized a truly pulseless patient within 10 secs. Recognition of pulselessness of the carotid artery by rescuers with basic cardiopulmonary resuscitation training is time-consuming and highly inaccurate. Although the carotid pulse check needs to be taught, its importance in the context of layperson basic life support should be de-emphasized.

Publications on paediatric anaesthesia: a quantitative analysis of publication activity and international recognition.

A comprehensive compilation of the current international literature on paediatric anaesthesia is lacking. The aim of this study was to identify all articles on clinical practice in paediatric anaesthesia, to name the respective journals, and to assess the publication activity and international recognition of selected countries for a 6-yr period (1993-1998). The search comprised an article-to-article evaluation ('hand search') of 12 peer-reviewed anaesthesia journals, as well as an Internet-based ('SilverPlatter') Medline-search (3,900 medical journals, US National Library of Medicine), both limited to original articles, case reports, reviews and editorials. Selected physical characteristics, for example the number of infants and children aged 0-14 yr old, the number of anaesthetists (specialists) and current impact factors (Science Citation Index) served to assess publication activity and international recognition. During the time period studied, 2259 articles (377/yr) were published on paediatric anaesthesia in 295 medical journals. The articles were primarily written in English (85.1%) and the majority originated from the USA (35.4%) and the UK (12.6%). The largest number of publications (77.7%) appeared in 29 anaesthesia journals, all referenced in Medline, with 46% being published by only five journals. Most authors published in journals of their home country/region. Authors from the UK ranked highest in publication activity, followed by those from Canada, Switzerland, Sweden and Denmark. The highest impact factor was achieved by US and UK authors. We conclude that publications on paediatric anaesthesia are clustered in a small number of journals and are written predominantly by authors from English-speaking countries, who achieved the highest international recognition.

The topics of international publications on paediatric anaesthesia from 1993 to 1998.

A comprehensive compilation of the current international literature on paediatric anaesthesia is still lacking. It was the aim of this study to identify all publications with a focus on paediatric anaesthesia, and to determine the spectrum of topics, as well as the publication type and language for the period between 1993 and 1998. All articles published in 12 major anaesthesia journals were evaluated and, additionally, a computerized, Internet-based Medline-search was performed using selected keywords. The analysis was limited to original articles, case reports, reviews and editorials. For the period between 1993 and 1998, a total of 2259 (377 per year) publications on paediatric anaesthesia were identified in 295 different journals, the majority of which were on the topic of 'providing anaesthesia' in children (n=1424, 63.0%). In contrast, publications on, for example, 'postanaesthesia care' (6. 3%), and 'organizational aspects of paediatric anaesthesia' (2.2%) were rare. Most articles were written in English (85.1%), and more than 50% reported original data (57.1%). Our results suggest that several topics may be of interest for future research and communication in the field of paediatric anaesthesia and new results should be published in English to reach a large international readership.

"Recommendations for uniform reporting of data following major trauma--the Utstein style" (as of July 17, 1999). An International Trauma Anaesthesia and Critical Care Society (ITACCS).

Basic and advanced care of trauma patients has always been an important aspect of prehospital and immediate in-hospital emergency medicine, involving a broad spectrum of disciplines, specialties and skills delivered through Emergency Medical Services Systems which, however, may differ significantly in structure, resources and operation. This complex background has, at least in part, hindered the development of a uniform pattern or set of criteria and definitions. This in turn has hitherto rendered data incompatible, with the consequence that such differing systems or protocols of care cannot be readily evaluated or compared with acceptable validity. Guided by previous consensus processes evolved by the ERC, the AHA and other International Organizations--represented in ILCOR--on 'Uniform reporting of data following out-of-hospital and in-hospital cardiac arrest--the Utstein style' an international working group of ITACCS has drafted a document, 'Recommendations for uniform reporting of data following major trauma--the Utstein style'. The reporting system is based on the following considerations: A structured reporting system based on an "Utstein style template" which would permit the compilation of data and statistics on major trauma care, facilitating and validating independent or comparative audit of performance and quality of care (and enable groups to challenge performance statistics which did not take account of all relevant information). The recommendations and template should encompass both out-of-hospital and in-hospital trauma care. The recommendations and template should further permit intra- and inter-system evaluation to improve the quality of delivered care and identification of the relative benefits of different systems and innovative initiatives. The template should facilitate studies setting out to improve epidemiological understanding of trauma; for example such studies might focus on the factors that determine survival. The document is structured along the lines of the original Utstein Style Guidelines publication on 'prehospital cardiac arrest'. It includes a glossary of terms used in the prehospital and early hospital phase and definitions, time points and intervals. The document uses an almost identical scheme for illustrating the different process time clocks--one for the patient, one for the dispatch centre, one for the ambulance and, finally, one for the hospital. For clarity, data should be reported as core data (i.e. always obtained) and optional data (obtained under specific circumstances). In contrast to the graphic approach used for the Utstein template for pre- or in-hospital cardiac arrest, respectively, the present template introduces, for the time being, at least, a number of terms and definitions and a semantic rather than a graphic report form. The document includes the following sections: The Section Introduction and background The Section on Trauma Data Structure Development: presents a general outline of the development of structured data using object-orientated modelling (which will be discussed in due course) and includes a set of explanatory illustrations. The Section on Terms and Definitions: outlines terms and definitions in trauma care, describing different types of trauma (blunt, penetrating, long bone, major/combined, multiple/polytrauma and predominant trauma). The Section on Factors relating to the circumstances of the injury describes the following items: cause of injury (e.g. type of injury (blunt or penetrating), burns, cold, crush, laceration, amputation, radiation, multiple, etc. Severity of Injury e.g. prehospital basic abbreviated injury score developed by the working group. The score contains anatomical and physiological disability data, with the anatomical scale ranging ordinally from 1. Head to 9. External; the physiological disability scale ranging ordinally from 0--unsurvivable. Mechanism of injury recording for transportation incidents etc. e.g. the type of impact, po

Prehospital trauma care.

Concepts regarding uniform reporting of data after trauma and regarding treatment of brain trauma patients at the scene have recently been agreed upon in consensus processes. Endotracheal intubation and alternatives are as controversially discussed as fluid resuscitation and helicopter transport of trauma victims. Long-term outcomes of trauma patients should more frequently be studied using the Quality of Wellbeing Scale.

Analysis of intrapulmonary O(2) concentration by MR imaging of inhaled hyperpolarized helium-3.

Inhalation of hyperpolarized (3)He allows magnetic resonance imaging (MRI) of ventilated airspaces. (3)He hyperpolarization decays more rapidly when interacting with paramagnetic O(2). We describe a method for in vivo determination of intrapulmonary O(2) concentrations ([O(2)]) based on MRI analysis of the fate of measured amounts of inhaled hyperpolarized (3)He in imaged regions of the lung. Anesthetized pigs underwent controlled normoventilation in a 1.5-T MRI unit. The inspired O(2) fraction was varied to achieve different end-tidal [O(2)] fractions (FET(O(2))). With the use of a specifically designed applicator, (3)He (100 ml, 35-45% polarized) was administered at a predefined time within single tidal volumes. During subsequent inspiratory apnea, serial two-dimensional images of airways and lungs were acquired. At least once in each animal studied, the radio-frequency excitation used for imaging was doubled at constant FET(O(2)). Signal intensity measurements in regions of interest of the animals' lungs (volume range, 54-294 cm(3)), taken at two different radio-frequency excitations, permitted calculation of [O(2)] in these regions of interest. The [O(2)] fractions in the regions of interest correlated closely with FET(O(2)) (R = 0.879; P < 0.0001). O(2)-sensitive (3)He-MRI may allow noninvasive study of regional distribution of ventilation and alveolar PO(2) in the lung.

["Topless" cardiopulmonary resuscitation? Should heart-lung resuscitation be preformed without artificial resuscitation?]. / Kardiopulmonale Reanimation "oben ohne"? Soll die Herz-Lungenwiederbelebung künftig ohne Beatmung erfolgen?

A paper published in various US journals on Emergency Medicine in 1997, has raised considerable concerns. The authors question if it is justified to continue to recommend initial ventilation as part of basic CPR when performed by lay-bystanders. A few aspects need to be discussed and some questions have to be answered before any changes in the current recommendations may even be considered: e.g. 1. How convincing does the available evidence support the following hypotheses: 1.1. Lay CPR without mouth-to-mouth-ventilation provides better outcome after cardiac arrest than lay CPR with mouth-to-mouth-ventilation. 1.2. Endotracheal intubation may be detrimental in patients suffering from hemodynamic compromises, particularly from VF. 2. Is it scientifically and ethically acceptable to design and perform prospective randomized controlled trials (RCTs) to evaluate the efficacy of those components of BCLS and ACLS which have in accordance with AHA-, ERC Guidelines and ILCOR Statements in the past been applied in millions of cardiac arrest victims and have obviously enabled the patients to lead a meaningful life after survival; under conditions of the proposed study design patients of the study group would be left without the treatment option ventilation, thus diminishing their chances of survival. Ad 1: The arguments presented by the authors are hardly convincing. The authors themselves state elsewhere that reluctance to perform mouth-to-mouth-ventilation should not represent a major problem because most cardiac arrests of cardiac etiology occur at home and in the presence of a relative or friend. Moreover, unreliable recommendations for mouth-to-mouth-ventilation (AHA), lack of training, retention of skills and knowledge, and a deficit in motivation include the main causes of the disappointingly low figures of bystander CPR worldwide. This situation cannot be improved simply by eliminating a lifesaving component of CPR-ventilation. Instead, the proposal to abandon the administration of unreasonably high ventilation volumes (800-1200 ml/breath) from the present guidelines and to recommend volumes ranging from 400-500 ml/breath recently made by the ERC should be given serious consideration. Furthermore, equipment and training manikins need to be adapted to these more reasonable volumes. Independently of the mechanisms of slow decreases in SaO2 after cardiac arrest (provided no compressions are performed) independently of gasping, ventilatory effects of standard compression or ACD-HCPR in the absence of mouth-to-mouth-ventilation, it is essential to realise that the patient's airways need to be maintained open at all times (this is unlike animal experiments where the airways are primarily kept open by the respective tissue structures): The minimum requirement of First Responder CPR is the guarantee that open airways are maintained. It may possibly be discussed if the present sequence of ABC might be changed to CAB, a practice adopted in the Netherlands many years ago, however, outcome trials an CAB have not been published to date. In addition, greater demands should be made of training requirements in BLS, attendance of refresher courses should be required, and other groups of the population should be included into these programmes than only relatives or friends of patients at risk of a cardiac arrest. The programmes need to be made mandatory for greater variety of groups and individuals to increase the efficacy and efficiency of bystander resuscitation. The hypotheses made by the above-mentioned authors are neither scientifically nor ethically acceptable. Ad 2: Pepe's argument regarding the efficacy of endotracheal intubation (ETI) in VF-patients has not been scientifically proven and lacks conclusive evidence. ETI serves to protect the airways and lungs against aspiration of regurgitated material and to facilitate artificial ventilation including PEEP, both under anaesthesia and resuscitation. The efficacy of ETI in the OR has long b