This overview reports on first experience with German DRGs version 1.0 from 2003, with special regard to relevant procedures and diagnoses of anaesthesiology. Basically, the G-DRGs are a translation of the AR-DRGs 4.1. Only the 2004 version represents a first real German DRG system. Particularly anaesthesiological measures for procedures which are normally performed without narcosis can lead to essentially relevant remuneration. In intensive care medicine, the hours of artificial ventilation must be recorded exactly. In the 2004 version of the G-DRGs, intensive medical performances are mainly differentiated regarding the time of ventilation, which leads to better payment than under version 1.0. In intensive care medicine, additional remuneration is only intended for dialyses and other organ-supporting procedures. Pain therapy is insufficiently documented in the G-DRGs. Although new codes of pain treatment are included in the G-DRGs, they do not lead to relevant remuneration. Diagnoses and procedures coded by the anaesthetist should be registered in the clinic information system without delay. Only non-anaesthesia-associated diagnoses, i.e. additional diagnoses resulting from the preanaesthetic check-up of the patient in the preanaesthetic department, should be checked by non-anaesthesiological physicians. The correct documentation and transfer of ASA classifications is necessary for additional charges in external quality management and to avoid financial sanctions. In our experience, regarding operated patients, anaesthetists can contribute a lot to enquiries by health insurance companies, e.g. whether the payment code for an in- or an out-patient should be used. Departments of anaesthesia should appoint an anaesthetist as DRG representative to supervise anaesthesiological coding and DRG-relevant procedures.
Among the many technical appliances for pain therapy which are currently available, the use of implantable drug pumps for prolonged pain treatment is of increasing importance. Since this kind of pain therapy can be used without any problems outside the hospital, it improves the quality of life of the patient. Furthermore, it is combined with a reduction of side-effects which frequently occur when analgesics are given orally or parenterally in big single doses. High initial costs are compensated by a good cost-benefit ratio of this kind of pain treatment, which enables the use of analgesics in low doses in out-patients. Based on the use of gas mixtures which can be compressed repeatedly, implantable mechanically-driven pumps are a nearly inexhaustible propulsion unit for drug infusions. The development of new gas mixtures and of innovative control mechanisms allows greater independence from surrounding influences and higher precision regarding infusion rates. Mechanically-driven pumps are characterized by prolonged functioning and low cost of purchase. Therefore, they will continue to be available on the medical market in future. Special progress in cardiac pacemaker therapy as well as further miniaturization of portable infusion pumps with peristaltic propulsion have led to the development of programmed implantable pumps with lithium batteries as energy sources. The advantages of these pumps, particularly those with "externally" programmable infusion rates (continuous, bolus, periodical bolus, etc.) point to the future. With these devices, evacuation and refilling of the pumps due to necessary changes of drug concentrations, as has to be done with mechanically working pumps with fixed infusion rates, are no longer necessary. Therefore, these programmable pumps can also be used for infusion of drug concentrates. At present, however, high costs and the battery-dependent limited duration of functioning of these devices are disadvantageous. As with cardiac pacemakers, battery exchange is necessary. Using implantable drug pumps, relevant changes of body temperature and atmospheric pressure lead to more or less considerable deviations of the infusion rates. These deviations differ from product to product and can be studied in the informative material published by the manufacturer.
Fifteen years ago, on the 28th of August 2004, one of the British pioneers of anaesthesiology, Sir Robert Reynolds Macintosh, died in Oxford. Since he had a major influence on the development of anaesthesia in Europe and the rest of the world, we felt it would be appropriate to review his life and work. Macintosh was the first Nuffield Professor of Anaesthetics in the University of Oxford, so we provide a brief biography of Lord Nuffield and describe the historical background to the creation of the chair. We then outline Sir Robert's early life and describe pre-war developments at Oxford, including the development of the calibrated Oxford vaporizer for ether and laryngoscope. We discuss the wartime research into survival at high altitudes, the design of life-jackets and the efficiency of methods of artificial ventilation, and then show how Sir Robert pioneered a more open approach to the problem of anaesthetic-related deaths. We list some of the anaesthesiological textbooks which were translated into German, and then describe how his overseas travels influenced the teaching of anaesthesiology all over the world. We record Sir Robert Macintosh's connections with East and West Germany and note how he encouraged the development of academic departments of anaesthesia worldwide.
Total intravenous anaesthesia has recently gained more interest in paediatric anaesthesia. However, the global experience with children is limited, therefore, the knowledge acquired in adult practice is often applied uncritically to the paediatric patient. Induction of anaesthesia by mask is a widely used and generally accepted technique; it has gained even more popularity since the introduction of sevoflurane into clinical practice. This drug has markedly improved the safety because of the reduced cardiovascular side-effects. The availability of venous access is a prerequisite for intravenous induction. Pain on injection, bradycardia, and difficulties in dosing the individual patient are the main drawbacks. Inhaled anaesthetics allow to monitor breath by breath the individual pharmacokinetics. On the other hand, maintenance of anaesthesia by an intravenous infusion of propofol is mainly based on assumptions, even when the drug is administered by computer-controlled pumps. Large aberrations from the predicted values can occur in the individual patient. Intraoperative awareness is possible, however, its incidence is generally underestimated. Paravenous infusion and pump dysfunction are typical complications of an intravenous technique. A reduced incidence of postoperative vomiting and agitation are recognised advantages of an intravenous technique. Propofol-infusion-syndrome results from prolonged administration in children and in adults. It can even occur after the use of the substance for a few hours. The duration of a safe period for administration is completely unknown, especially for neonates and infants. In summary, both techniques can be used in children; both have advantages and drawbacks. Because the experience with small children is very limited, we have to re-evaluate our practice with a critical eye day by day.
Remifentanil is an esterase-metabolized ultra-short acting mu-agonist opioid with a rapid clearance. The aim of this study was to determine the efficacy of remifentanil infusion for the short-lasting, but painful, transvaginal puncture for oocyte retrieval. Eighty consenting adult women (ASA I and II) aged 30.5 +/- 5 years and with a body weight of 69.1 +/- 9.1 kg were enrolled in this prospective study. After an oral premedication with 7.5 mg midazolam, all patients received 3 l/min oxygen. Subsequently, the remifentanil infusion was started with a rate of 0.3 microg/kg/min. Remifenanil doses were adjusted as needed for painless puncture and sufficient oxygen saturation in steps of 0.05 microg/kg/min. Dosage requirements, blood pressure, heart rate, oxygen saturation (pulse oxymetry, SaO2) and the level of analgesia were recorded every 3 minutes. Follicular aspiration lasted 11.8 +/- 4.1 min and the time of remifentanil infusion was 18.7 +/- 4.6 min. Dosage requirements of remifentanil were 0.3 microg/kg/min in 48.7% of all patients, but 27.8% needed only 0.25 microg/kg/min and 16.6% needed only 0.2 microg/kg/min. However, 4.2% of patients needed 0.35 microg/kg/min and 2.7% of all cases needed 0.4 microg/kg/min. Vital parameters remained nearly unchanged. Oxygen saturation decreased significantly from 99.2 +/- 0.7% to 98.2 +/- 2.4% after 3 min and to 94.9 +/- 7.2% after 10 min. Nine women showed motoric reactions to puncture. In many cases, the infusion of remifentanil after premedication with midazolam provided a suitable and satisfying anaesthesia for oocyte retrieval. Some patients, however, showed motoric reactions to vaginal puncture, while in other cases significant and clinical relevant decreases in Hb-oxygen saturation occurred. Therefore, we no longer carry out remifentanil infusion for transvaginal oocyte retrieval. We now prefer a remifentanil infusion of 0.2 microg/kg/min and propofol (1 mg/kg initially with intermittent doses of 0.5 mg/kg) combined with assisted ventilation by mask.
Mitochondrial disorders encompass a group of syndromes produced by genetic defects that disrupt mitochondrial energy production. The impaired mitochondrial energy supply affects nearly all organs and tissues leading to a variable clinical presentation. The possible multisystem involvement complicates the management of anaesthesia and perioperative care. Exact knowledge of the path physiology of mitochondrial diseases may help to avoid perioperative anaesthesiological complications. This report describes the anaesthetic management of a patient with a mitochondrial disorder during combined pancreatic and renal transplantation, and discusses some of the anaesthetic implications of mitochondrial diseases. Due to the potential susceptibility of patients with mitochondrial diseases to malignant hyperthermia, anaesthesia was induced and maintained as total intravenous anaesthesia using propofol, alfentanil and cis-atracurium. In addition, the patient was treated intraoperatively with hydrocortisone (initial bolus of 50 mg followed by a continuous infusion of 4.8 mg/h) and insulin (continuous infusion of 2 IE/h) in order to manage the adrenocortical insufficiency as well as to treat the diabetes mellitus. Using this anaesthetic technique, satisfactory haemodynamic and metabolic conditions were achieved during surgery. The postoperative period, however, was marked by severe respiratory complications.
Alcaptonuria is a very rare enzymatic disease with a compromised degradation of the amino acids phenylalanine and tyrosine. As a consequence, homogentisic acid accumulates, most of which is cleared by the kidneys. In time, homogentisic acid forms black pigment, which accumulates throughout the body in connective tissue such as cartilage and joints. Apart from superficial discoloration, the most clinical manifestation of the disease is arthropathy, starting in middle age. From the anaesthesiologist's point of view, there is a severe risk of difficult airway because of an advanced stiffness of the cervical spine and a reduced mouth opening in these patients. Due to deformity and stiffness of the spine, difficulties in spinal and epidural anaesthesia must be reckoned with. A further risk for patients with alcaptonuria is cardiac involvement, which occurs later than degenerative changes of the joints. The accumulated pigment most likely adds to the development of degenerative changes of the valve and coronary artery disease and there is an increased risk of developing aneurysms in atherosclerotic altered vessels. Therefore, at the preoperative visit a thorough clinical cardiovascular examination should be performed. Cardiological advice and an examination should be sought from a specialist. For intubation, fibreoptic procedures should be considered. Anaesthetic management and perioperative monitoring are determined by the results of the cardiological examination and the type and extent of the operation.
We investigated the effect of a ventilation with an FiO2 of 1.0 on arterial and hepatic venous oxygenation in 23 Göttingen minipigs. Under balanced anaesthesia (isoflurane/fentanyl), a fibreoptic catheter was placed into a hepatic vein. The correct position of the tip of the catheter was controlled manually after laparotomy. After measurement of baseline values (arterial and hepatic blood gases, ShvO2), in 13 minipigs normoventilation with an FiO2 of 1.0 was performed for 15 minutes. Thereafter, ventilation was continued with an FiO2 of 0.4. In the control group (n = 10), the animals were oxygenated with an FiO2 of 0.4 permanently. The changes due to hyperoxia were measured in hepatic venous oxygen saturation (ShvbgaO2: from 81.2 +/- 1.43% to 87.5 +/- 1.77%, ShvoximO2: from 82.6 +/- 1.14% to 90.5 +/- 0.90%), arterial (from 217.5 +/- 5.0 mmHg to 467.2 +/- 22.0 mmHg) and hepatic venous (from 51.8 +/- 2.0 mmHg) oxygen partial pressure. We found a correlation between hepatic venous oxygen partial pressure und ShvbgaO2 in the blood (r = 0.84, p < 0.001) and between ShvO2 (ShvbgaO2/ShvoximO2), which was either measured directly in the blood or by a fibreoptic catheter (r = 0.6, p < 0.001). Whereas the increase in ShvO2 during hyperoxia may be a result of increased arterial supply, the decrease in ShvO2 after the end of hyperoxia below baseline values needs further investigations. The continuous fibreoptic measurement of ShvoximO2, also under hyperoxic conditions is a valuable parameter for the monitoring of hepatic venous oxygenation.
Regional anaesthesia is well established in modern clinical practice. It provides a safe and reliable alternative to general anaesthesia, but is also of high clinical value in combination procedures. Our knowledge of perioperative pathophysiological characteristics increasingly indicates that regional blocks lead to excellent analgesia und profoundly modulate the postoperative stress response and thus, they can have therapeutic influence on postoperative convalescence, on the functional operation result and on the avoidance of frequent postoperative complications. Given the increasing number of older patients with nigher co-morbidity, this is of particular therapeutic importance, but also has economic implications. The continuous techniques of regional anaesthesia, which at first sight are more time-consuming and expensive, may shorten the time to extubation after major abdominal procedures, accelerate postoperative recovery and prevent postoperative adverse outcomes. Optimised physiotherapy after total knee arthroplasty or improvements in pulmonary and gastrointestinal function demonstrate the capabilities of regional anaesthesia to facilitate postoperative rehabilitation. With regard to an improved organ function and a possibly shorter hospital stay, regional techniques appear cost-effective. It is important that regional anaesthesia is carried out on the basis of a clear individual indication, which considers the entire perioperative treatment process.
Skilful analgesia is self-explanatory and needs no justification. In contrast to this, preclinical general anaesthesia is of relative value and depends, in part, on the professional qualities of the emergency physician. Analgesic and anaesthestic drugs should be administered via a safe intravenous line. In contrast to rapid sequence induction of general anaesthesia, analgesic drugs should be titrated. The patient has to be monitored by the vigilance of the physician and adequate technical equipment. Metamizol is used for treatment of minor and medium pain, while morphine is indicated for treatment of major pain, especially in internal patients. Fentanyl is mainly used for total intravenous anaesthesia with controlled ventilation. (S)-ketamine is indicated for analgesia, analgosedation and anaesthesia in trauma patients, except isolated or dominating craniocerebral trauma, and in special internal cases. Midazolam is used for sedation or, in combination with (S)-ketamine or fentanyl, total intravenous anaesthesia. Etomidate is especially useful for induction of emergency patients with sufficient cardiovascular stability. Suxamethonium is the standard relaxant for endotracheal intubation during rapid sequence induction. If longer muscle relaxation is necessary, vecuronium should be used due to its simple storage and general lack of untoward effects. Butylscopolamin is used in colic pain, either alone or in combination with analgesic drugs. Haloperidol is indicated in acute psychotic syndromes as well as psychomotoric and alcohol-dependent excitation. On the whole, profound pharmacological and practical knowledge is necessary, although restricting oneself to just a few drugs increases the depth of one's personal experience.
As a basis for quality assurance measures, we analysed over a period of three years all iatrogenic tracheobronchial injuries that had to be repaired operatively at a university hospital. Twelve patients were affected. In most of these cases, the injuries were the result of an intubation during resuscitation attempts prior to or after admission to hospital (6 patients; 4 of them died later). The ruptures of 5 patients were due to complications of a dilational tracheostomy (1 died). In one case the laceration occurred in the course of a reoperation after oesophagectomy (conservative treatment after dehiscence of the tracheal suture). The tracheobronchial ruptures (length: 2 to 8 cm) were located in the pars membranacea and had surgical repair through a thoracotomy on the right side. During the period of this investigation, 43,773 elective intubations were performed. No such serious tracheal injuries were observed. The cause of death in the patients with tracheal injuries was mainly the underlying disease (resuscitation after myocardial infarction; tracheostomy because of pulmonary failure in septic disorders); however, it is likely that the injuries or the surgical intervention played an additional role in the negative outcome of the patients. The conclusion is that this complication rate must be reduced by in-service training and alteration of the procedures.
It is generally believed that in hypertensive patients both beta adrenoreceptor antagonists and calcium channel blockers can be continued up to the day of surgery without provoking problems with cardiovascular stability intra- and postoperatively. The same, however, has not been definitively established for angiotension converting enzyme inhibitors (ACEIs). A patient who was taking the ACAI enalapril for hypertension underwent two similar operations--right total hip replacement and three years later left--both with spinal anaesthesia. In the initial case, she received her enalapril on the morning of surgery, while for the second procedure, enalapril was stopped 48 hours earlier. Hypotension occurred which required more than 5 times the dose of etilefrin to maintain suitable blood pressure during the first instance as compared to that when enalapril had been discontinued 48 hours earlier. Spinal anaesthesia in conjunction with an ACEI may result in severe hypotension as seen in this patient. In view of this, it is suggested that in contrast to other antihypertenisve drugs, ACEIs should be withdrawn well in advance of spinal anaesthesia.
Cricoid pressure is a simple and effective measure to prevent regurgitation of gastric juice and content. This procedure, which prevents a possible reflux by compression of the oesophagus between the cricoid cartilage and the cervical vertebral bodies, is generally acknowledged in clinical practice, although there is lack of scientific evidence regarding its effect on the outcome of patients at risk of aspiration. However, there is only a rare incidence of complications as long as cricoid pressure is used with exact indication, considering the contraindications and correct performance. Especially important are the optimal force applied on the cricoid and the duration of application. However, there is a lot of evidence in the literature that the knowledge of anaesthetists about the method and technique of cricoid pressure is rather unsatisfactory. Thus, the starting point for improving the efficiency and safety of cricoid pressure seems to be better teaching and training.
With increasing drug abuse of cocaine, the chances are growing that an anaesthetist comes into contact with an acutely intoxicated patient or chronic cocaine user while on call or during his daily routine. In South America chewing coca leaves is daily practise, while in the industrialised world the drug is sniffed, smoked or injected intravenously. Clinically, cocaine is used topically in ENT and ophthalmology due to its local analgesic and strong vasoconstrictive properties. Cocaine has a similar effect on the CNS as amphetamines and produces euphoria and hallucinations. Cocaine acts indirectly on sympathetic stimulation, release of dopamine and inhibition of catecholamine metabolism. It is metabolised in the liver and by serum esterases. Intoxication with cocaine leads to respiratory depression, arrhythmias, ventricular fibrillation and death. If an emergency operation during acute cocaine intoxication is necessary, all sympathomimetic anaesthetic drugs must be avoided. A deep anaesthesia must be provided to reduce the risk of cardiovascular complications. In the literature, anaesthesia is regarded as safe for patients with chronic cocaine misuse after abstinence of 24 hours. This case report shows that, even without acute intoxication, severe cardiovascular problems are possible in patients with chronic cocaine abuse. Hence, we recommend a cocaine-free interval of at least one week before elective surgical procedures.
Tracheo-bronchial lesions in blunt chest trauma are rare--the incidence is about 1%--but potentially life-threatening events. Indirect signs such as pneumothorax, pneumomediastinum, subcutaneous emphysema or an insufficient expansion of the lungs after drainage of a pneumothorax are ominous. The fastest and most reliable method to assess the definite diagnosis of tracheo-bronchial lesion is fibre-optic tracheobronchoscopy. Early surgical treatment is mandatory to prevent major pulmonary resection. This case shows that computer tomography might fail to provide the right diagnosis. Independent lung ventilation is an option to protect the bronchial anastomosis during the early postoperative period. Reported here is the case of a young man who sustained a total traumatic rupture of the right main stem bronchus after being thrown from the passenger seat through the windshield of a motor vehicle. When the emergency doctor arrived on the scene, he found the patient with dyspnoea and massive thoracic subcutaneous emphysema. Reduced breath sounds on the left and no breath sounds on the right side led to an immediate placement of two chest tubes and controlled mechanical ventilation. After primary care in a district hospital, the patient was transferred to our university hospital for further treatment of his head injury. On admission, the patient was making breath sounds on both sides and a CT scan showed no clear sign of a tracheo-bronchial lesion. After neurosurgical intervention, the diagnosis of a rupture of the right main stem bronchus was made with delay by fibre-optic bronchoscopy. The patient was intubated with a left-sided double lumen endotracheal tube followed by surgical end-to-end anastomosis of the lesion. The initial postoperative ventilator support consisted of BIPAP-mode ventilation of the left lung, while the right lung was kept open with positive airway pressure. Forty-eight hours later, synchronised independent lung ventilation with two ventilators was established to protect the surgical result. The ventilation was switched to conventional mode a further 48 hours later. Extubation and the remaining ICU stay were uneventful.
The differential-diagnostic strategy and the order of precedence of most diverse radiologic diagnostic procedures are discussed based on a case of retroperitoneal bleeding. Apart from iatrogen-caused bleedings, the therapeutic anticoagulant therapy in the context of the patient's disease, haemodialysis or a rare, spontaneously-occurring retroperitoneal bleeding play a substantial role. In the order of precedence of radiologic diagnostic procedures for fast diagnosis of a retroperitoneal haematoma, the abdomen CT-scan is the preferred method.
In alcohol-dependent in-patients, an adequate drug prophylaxis should be made in order to lower the degree of a developing alcohol withdrawal syndrome (AWS) or to prevent a life-threatening delirium tremens. Pre-condition of successful therapy is a precise diagnosis. In patients, the beginning of whose abstinence is known, carefully-targeted pharmacological interventions can prevent severe imbalances of neurotransmitters. Typical time courses of destabilisation of neural balances should be considered. Since there is no single drug which is able to influence various transmitter systems, normally the use of drug combinations is necessary. In ENT-patients, traumatologic patients and patients from the department of maxillo-facial surgery, screening methods based on a simply-structured questionnaire relating to information from the patient and his surroundings and selected laboratory parameters should be used. High-risk patients who could get an AWS or delirium tremens should be treated prophylactically during their oral premedication period. Important drugs for successful prophylaxis of an AWS are benzodiazepines, clonidin, magnesium and vitamin B 1. A close-meshed control of the glucose metabolism, electrolyte and acid-base balance should be performed. Neuroleptica can be used if there is any indication for their adjuvant use. In severe cases that require deep sedation or hypnosis, propofol or gamma-hydroxy-butyric acid should be used. Perioperative infusion of alcohol as a prophylactic agent against delirium tremens is regarded as an obsolete therapeutic measure for ethical reasons and because equally good or better results can be achieved by carefully-targeted drug therapy. Due to its easy use, however, the application of alcohol has not yet completely disappeared from the therapeutic spectrum.
Over the last years several clinical studies have modified the guidelines for preoperative fasting to reduce the risk of pulmonary aspiration. In most western countries the following guidelines are accepted: for clear liquids 2 hours, breast feeding 4 hours, small meals and breast milk substitutes 6 hours, heavy meals 8 hours. Since preoperative smoking is acknowledged as a risk factor, it should be ceased in most clinics 6 hours before induction of anaesthesia, as well. Smoking, however, does not increase the risk of pulmonary aspiration, as is often maintained, but increases the risk of postoperative pulmonary complications. To reduce the risk of perioperative pulmonary complications, cessation of smoking is necessary 8 weeks before operation. Stopping smoking only a few days before operation and anaesthesia even tends to increase the risk of pulmonary complications. Regarding cardiac complications, cessation of smoking 12 hours before anaesthesia is sufficient to reduce the incidence of cardiac ischaemia.
Based on a computer simulation programme, the accuracy of the Graseby 3400 syringe pump was tested for its use in a feedback control system of the neuromuscular block. Firstly, a calculation of errors to determine the difference between the target and actual flow rates was carried out. Next, the characteristic curves of the syringe pump were determined under different flow and sampling rates to correct the application software of the feedback controller with a view to obtaining the correct flow rates online. It was discovered that, particularly with short 12 s sampling rates, dose-dependent errors of almost 100% were provable. Therefore, the application of a robust controller and integration of the characteristic curves at the outlet of the controller software are required. For the adoption of syringe pumps in medical feedback control systems, definite determination of the actual infusion quantity using an exact calculation of errors is required. Especially in cases of short sampling rates in combination with low infusion quantities, the syringe pump comes almost to a standstill, which results in extreme differences between target and actual flow rates.
