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B M Graf

Publications and source records attributed to B M Graf.

At least 19 recordsLinked to original sources
PubMed2007

[Teaching and simulation. Methods, demands, evaluation and visions].

Since 1st October 2003 the new German "Approbationsordnung für Arzte" (Medical Licensing Regulations) requires an increasing amount of small group teaching sessions and encourages a multidisciplinary and more practical approach to the related topics. In 2004 the German Society of Anaesthesiology and Intensive Care Medicine has provided almost all anaesthesia faculties of German Universities with equipment for full-scale simulation. This article describes methods for a simulation-based medical education training program. Basic requirements for a successful training program using full scale simulators are the provision of an adequate logistical and material infrastructure, teacher attendance of train-the-trainer courses, implementation in the medical curriculum and an instructor-student ratio of 1:3, equivalent to that for bedside teaching. If these requirements were fulfilled, medical students scored the simulation scenarios "induction of anaesthesia", "acute pulmonary embolism", "acute management of a multiple trauma patient" and "postoperative hypotension" as 1.5, 1.6, 1.5 and 1.5, respectively, on a scale of 1-6. These scores were better than those given for other segments of the curriculum.

Anesthesia↗
PubMed2007

[Treatment of oncology patients in the final stadium of disease by prehospital emergency physicians].

BACKGROUND: Presently and even more in the near future more cancer patients will be treated at home especially in the final stage of their disease. For this reason the prehospital emergency system will be confronted with the specific needs of these patients. Palliative care is not part of the German model of post-graduate training regulations for emergency medicine and palliative care teams (PCT) are only involved in the treatment of cancer patients in emergency situations. METHODS: Over a 12-month period we retrospectively analysed all emergency cases that had been categorised as final cancer stage at 2 emergency sites (one air-based, the other ground-based) involving physicians in an out-of-hospital setting. We analysed all cases for indications of emergency call, prehospital treatment and involvement of a PCT in the treatment of symptoms. RESULTS: For this period we analysed 2,765 emergency documents and identified more than 2.5% as emergency calls by cancer patients or their relatives (the majority of patients had been in the final stage of the disease). Most emergency calls occurred at times when no general practitioner was on duty and acute dyspnoea (42.7%) was the prominent diagnosis. After emergency treatment 61.8% patients had been admitted to hospital. In most settings a PCT was not involved in the treatment of palliative care patients or their relatives (92.7%). CONCLUSIONS: Our data demonstrate that care of cancer patients in the final stage of the disease is relevant in emergency medicine. These patients are in need of help based on principles of palliative care. Under these circumstances cooperation of the medical disciplines (emergency and palliative medicine) concerned seems to be necessary. This may increase the possibility for patients to stay at home for the last days of their life. Because of this we are convinced that basic knowledge of palliative care should be integrated into the German model of post-graduate training regulations for emergency care. Combining parts of the curricula (palliative and emergency medicine) it would be possible for emergency physicians to guide their treatment by the ideas and strategies of palliative care. But we are also convinced that the system of PCT should increase and become more involved in prehospital care in emergency cases of palliative care patients.

Emergency Medical Services↗
PubMed2006

Evaluation of the CTrach--an intubating LMA with integrated fibreoptic system.

BACKGROUND: The laryngeal mask airway CTrach (CTrach) is a variant of the intubating laryngeal mask airway. It provides visualization of the larynx during intubation and is designed to increase the success rates of ventilation and tracheal intubation. METHODS: Sixty healthy anaesthetized and paralysed patients with normal airways were studied. The success rates of ventilation and intubation using CTrach were determined. Laryngeal view scoring ranged from grade I (full view of arytenoids and glottis), II (arytenoids and glottis partly visible), III (view of arytenoids, glottis or epiglottis blurred, or view clear with only epiglottis visible) to IV (no part of larynx identifiable). Adjusting manoeuvres were undertaken to improve the laryngeal view in grades II or worse. RESULTS: CTrach insertion and ventilation was possible in all patients. Initial views were scored as grade I in 22 (36.7%), grade II in 14 (23.3%), grade III in 7 (11.7%) and grade IV in 17 (28.3%) patients. Adjusting manoeuvres were undertaken in 38 patients with grade II and worse (63.3%), resulting in improved views of grade I in 33 (55.0%), grade II in 18 (30.0%), grade III in 4 (6.7%) and grade IV in 5 (8.3%) patients. Tracheal intubation was successful in 58 (96.6%) patients at first attempt and in one at second. Tracheal intubation failed once. CONCLUSIONS: In 60 patients with normal airways, the CTrach was used successfully for ventilation, with successful tracheal intubation in 59 patients. Tracheal intubation can be successful despite grade III or IV views.

Adolescent↗
PubMed2006

[New perspectives for simulator-based training in paediatric anaesthesia and emergency medicine].

Anaesthesia and emergency medical care for infants and toddlers is often associated with high clinical demands and specific challenges. Nevertheless, a significant proportion of interventions is performed by anaesthetists and emergency physicians with no specialised paediatric training and little experience in the management of anaesthetic incidents and emergencies specific to these age groups. Extensive studies have demonstrated a close inverse correlation between the level of specialisation and perioperative morbidity and mortality. However, clinical circumstances and the relatively small number of paediatric cases at many institutions often hinder the establishment of improved training concepts. Recently, high-fidelity infant simulators have become available, which permit authentic exposure to a large spectrum of scenarios in paediatric anaesthesia and emergency medicine. A multimodular concept of training, including such simulator-based techniques, may relieve the widespread shortage in clinical experience, and hence greatly facilitate improvement of quality of care and patient safety.

Anesthesiology↗
PubMed2006

[LMA CTrach: initial experiences in patients with difficult-to-manage airways].

BACKGROUND: The Intubating LMA was designed to facilitate blind intubation and to provide ventilation between two intubation attempts. However, blind intubation can be associated with a risk of oesophageal penetration, therefore, a flexible bronchoscope is frequently used to assist tracheal intubation. This leads to increased burdens on materials and personal resources and prolongs intubation times. Hence the LMA CTrach laryngeal mask airway (CTrach) was developed with an integrated fibreoptic system which can be connected to a monitor for visualisation of the larynx during intubation. METHODS: We detail the initial experience gained with the practical handling of the CTrach and the application in 10 patients with difficult-to-manage airways. Laryngeal views were graduated in a CTrach-specific classification from grade I (clear view of the arytenoids, glottis and epiglottis) to grade IV (no part of the larynx can be identified). Adjusting manoeuvres were defined to improve the view of laryngeal structures. RESULTS: All patients could be successfully ventilated with the CTrach. Ventilation quality was rated adequate in nine and possible in one patient. The initial distribution of the laryngeal view between grades I-IV was 1/2/1/6 and after adjusting manoeuvres to improve the laryngeal view the grade distribution was 3/5/0/2. Intubation through the CTrach was successful in all patients, nine at first and one at the second attempt. CONCLUSION: In this small sample of patients with difficult-to-manage airways, the CTrach yielded high success rates for both ventilation and tracheal intubation. Adjusting manoeuvres can improve the laryngeal view further.

Anesthesia, Inhalation↗
PubMed2006

[Perioperative fluid management: an analysis of the present situation].

Optimal perioperative fluid management is still controversial. Besides well known perioperative hypovolaemia, hypervolaemia has an influence on perioperative morbidity and mortality, particularly with regard to the patient's medical history, a reduced cardiac and pulmonal function and the operation itself. The concepts of preoperative, intraoperative and postoperative fluid administration are neither adequately validated, nor sufficiently integrated into a perioperative concept. At the present, moderate fluid administration to improve preoperative and postoperative outcome is safe in minor or medium surgical procedures. High-risk surgical patients benefit from a time-oriented or/and goal-oriented monitored fluid therapy. In the past only little attention has been concentrated on postoperative fluid management, but may be stimulated by the new concepts of fast track surgery.

Blood Volume↗
PubMed2006

[Terminally ill tumor patients in emergency medical care].

We report about an emergency case of a female patient with terminal carcinoma of the ovary. On the basis of this case it becomes evident that palliative care questions are also important in emergency medicine. In this situation cooperation of the medical disciplines involved appears urgently necessary. This may allow the possibility for terminally ill patients to stay at home in the last days of life.

Aged↗
PubMed2006

GABAmimetic intravenous anaesthetics inhibit spontaneous Ca2+ -oscillations in cultured hippocampal neurons.

BACKGROUND: Spontaneous Ca2+ -oscillations are a possible mechanism of Ca2+ -mediated signal transduction in neurons. They develop by a periodical interplay of Ca2+, which enters the neuron from the extracellular medium and triggers Ca2+ release from the endoplasmic reticulum (ER). Ca2+ -oscillations are terminated by reuptake into the ER or plasmalemmal extrusion. Spontaneous Ca2+ -oscillations are glutamate dependent and appear to be responsible for neuronal plasticity and integration of information. Here, we examined the role of the gamma-aminobutyric acid (GABAA) receptor on spontaneous Ca2+ -oscillations and studied the effects of the anaesthetics midazolam, thiopental and the non-anesthetic barbituric acid on spontaneous Ca2+ -oscillations. METHODS: Hippocampal neuronal cell cultures of 19-day-old embryonic Wistar rats 17-18 days in culture were loaded with the Ca2+ -sensitive dye Fura-2AM. Experiments were performed using dual wave-length excitation fluorescence microscopy and calibration constants were obtained from in situ calibration. RESULTS: Spontaneous Ca2+ -oscillations are influenced by the GABAA receptor. The intravenous anaesthetics midazolam and thiopental suppressed the amplitude and frequency reversibly in a dose-dependent manner with EC50 in clinically relevant concentrations. This effect was mediated via the GABAA receptor as it could be reversed by the GABAA receptor antagonist bicuculline. In contrast, the application of barbituric acid had no effects on the spontaneous Ca2+ -oscillations. CONCLUSION: Spontaneous Ca2+ -oscillations are influenced by the GABAA receptor. Spontaneous Ca2+ -oscillations might represent an interesting model system to study anaesthetic mechanisms on neuronal information processing.

Anesthetics, Intravenous↗
PubMed2003

[High resolution fluorescence microscopy in combination with mathematical modelling. First evidence of sub-cellular anesthetic effects on Ca2+ sparks in situ].

Volatile anesthetics used in daily clinical routine, are associated with a rare but life-threatening disease, malignant hyperthermia. To date it is well known that, with the exception of xenon and nitrous oxide, all volatile anesthetics have the potential to trigger calcium (Ca(2+)) release from the sarcoplasmic reticulum, thereby influencing the Ca(2+) homeostasis in muscle fibers. The effects of volatile anesthetics have been previously studied by recording Ca(2+)-activated force transients in muscle fibers and by quantifying the effects on isolated intracellular Ca(2+)-release channels (ryanodin receptors). The use of high resolution fluorescence microscopy methods in combination with spatio-temporal mathematical models allows the effects of volatile anesthetics on functional clusters of ryanodin receptors in mammalian skeletal muscle fibers to be studied in situ for the first time.Thus, the analysis of cellular Ca(2+)-activated force production and single channel properties in conjunction with mathematical models allows the quantification of the effects of volatile anesthetics on Ca(2+)-release in the natural physiological environment on the basis of the underlying molecular architecture. In addition to the basic understanding of alterations in the Ca(2+) homeostasis induced by volatile anesthetics in muscle and nerve cells, the results are also of direct clinical importance for the understanding of the pathogenesis of malignant hyperthermia,where ryanodin receptor mutations are currently thought to result in an increased Ca(2+) release under the influence of volatile anesthetics.

Anesthetics, Inhalation↗
PubMed2003

[Toxicology of local anesthetics. Clinical, therapeutic and pathological mechanisms].

Regardless of their specific physico-chemical properties and chemical structures, all local anaesthetic agents block neuronal voltage-gated sodium channels, and thus suppress conduction in peripheral nerves. Since these ion channels ubiquitously appear in excitable membranes, systemic accumulation of local anaesthetic agents may affect the functional integrity of these structures. Clinically, local anaesthetic-induced systemic toxicity results in central nervous and cardiovascular malfunction. With regard to CNS toxicity, symptoms which are largely drug-independent appear in a characteristic biphasic sequence. Nevertheless, the plasma levels necessary to provoke these symptoms are to a large extent agent-specific. Initially, these toxic mechanisms are due to a selective blockade of cortical inhibitory neurons, which enables the formation of seizure potentials within subcortical structures. With high cerebral drug levels, however, excitatory neurons are also increasingly blocked, resulting in coma, apnoeic episodes and circulatory failure. Direct cardiac effects of local anaesthetics can be divided into (i) stereospecific inhibition of intracardial conduction and (ii) unspecific inhibition of myocardial energy supply and ion channels. The corresponding spectrum of symptoms is not uniform and may range from extreme bradycardia, (malignant) ventricular arrhythmia to refractory cardiac arrest. Local tissue toxicity has to be strictly delimited from systemic toxicity and allergies, respectively, which are mainly caused by aminoester agents. Local anaesthetics may cause neuronal and striated muscle injury at the site of injection. With regard to (central) neurotoxicity, "transient neurologic symptoms" and "cauda equina syndrome" have been increasingly recognised. However, the clinical relevance of local anaesthetic-induced myotoxicity is still controversly discussed. In order to avoid systemic accumulation of local anaesthetic agents, several safety procedures have to be considered during the application of these drugs. The treatment of systemic toxicity is strictly dependent on the expression of symptoms. However, hypoxia and acidotic episodes must be avoided and must be treated aggressively.

Anesthetics, Local↗
PubMed2002

[Man at risk. Preventive strategies and risk management for patient safety].

Anaesthesia-related risk has been significantly reduced within the last decade. Nevertheless the risk and the possibility of dying or suffering permanent damage still exist. To improve patient safety, risk assessment and analysis must lead to the development of preventive strategies. For this purpose anaesthesia can rely on the concepts of other "high reliability" organisations such as aviation or nuclear power plants. Analyses of critical incidents in the different fields confirm that next to technical problems human factors account for most of the preventable mishaps. Human factors are responsible for individual mistakes as well as for organisational errors. Therefore besides traditional concepts of risk reduction (e.g. guidelines) new strategies (e.g. full-scale simulation) must be applied to minimise the negative impact of human factors on patient safety. Risk management has to consider technical, organisational and human factors to implement a higher standard of patient safety.

Anesthesia↗
PubMed2002

Comparison of caudal and intravenous clonidine in the prevention of agitation after sevoflurane in children.

BACKGROUND: In children, sevoflurane anaesthesia is associated with postanaesthetic agitation, which is treated mainly with opioids. We compared the effectiveness of epidural and i.v. clonidine in the prevention of this postanaesthetic agitation. METHODS: Eighty children aged 3-8 yr (ASA I-II) received standardized general anaesthesia with inhaled sevoflurane and caudal epidural block with 0.175% bupivacaine 1 ml kg-1 for minor surgery. The children were assigned randomly to four groups: (I) clonidine 1 microgram kg-1 added to caudal bupivacaine; (II) clonidine 3 micrograms kg-1 added to caudal bupivacaine; (III) clonidine 3 micrograms kg-1 i.v. and caudal bupivacaine; and (IV) caudal block with bupivacaine, no clonidine (control). A blinded observer assessed the behaviour of the children during the first postoperative hour. Secondary end-points were the time to fitness for discharge from the postanaesthesia care unit, and haemodynamic and respiratory variables. RESULTS: The incidence of agitation was 22, 0, 5 and 39% in groups I, II, III and IV respectively (P < 0.05 for groups II and III compared with group IV). During the first hour after surgery, patients in groups II and III had significantly lower scores for agitation than group IV patients. Time to fitness for discharge did not differ between the four groups. CONCLUSIONS: Clonidine 3 micrograms kg-1 prevented agitation after sevoflurane anaesthesia, independently of the route of administration. The effect of clonidine appears to be dose-dependent, as an epidural dose of 1 microgram kg-1 failed to reduce it.

Adrenergic alpha-Agonists↗
PubMed2001

[Peripheral nerve block. An overview of new developments in an old technique].

General anaesthesia and peripheral neuronal blockade are techniques which were introduced into clinical practice at the same time. Although general anaesthesia was accepted significantly faster due to effective new drugs and apparent ease of handling, neuronal blockade has recently gained great importance. The reasons are in particular newer aids such as industrially produced catheter sets, nerve stimulators and ultrasound guidance which have facilitated that these economical techniques can be used not only for intraoperative anaesthesia but also for perioperative analgesia without any major risks for the patients. In parallel to epidural anaesthesia a change of paradigms has recently taken place using catheter instead of single-shot techniques. This allows the loading dose of the local anaesthetics to be installed in a safe way, to reload the dose when intraoperatively required and to extend the analgesia perioperatively by this technique using lower concentrations of the same drugs or drug combinations. A great number of short, middle or long acting local anaesthetics are available to choose the right drug for any particular case. Short and middle acting drugs are characterised by a faster onset compared to long acting drugs, but toxic plasma levels are seen during long time application causing seizures or drowsiness or by using prilocaine methemoglobin. Therefore long acting local anaesthetics such as bupivacaine, ropivacaine or levobupivacaine are the first choice drugs for long time application via peripheral nerve catheters for perioperative anaesthesia and analgesia. By using low concentrations of these potent drugs even for a longer period of time, no toxic plasma levels are seen with the exception of artificial intravasal injections. Additives such as opioids and alpha 2-sympathomimetics are also used. While the use of opioids is controversial, alpha 2-sympathomimetics are able to accelerate the onset and to extend the duration of regional anaesthesia and analgesia.

Animals↗