Legal and ethical implications of defining an optimum means of achieving unconsciousness in assisted dying.

A decision by a society to sanction assisted dying in any form should logically go hand-in-hand with defining the acceptable method(s). Assisted dying is legal in several countries and we have reviewed the methods commonly used, contrasting these with an analysis of capital punishment in the USA. We expected that, since a common humane aim is to achieve unconsciousness at the point of death, which then occurs rapidly without pain or distress, there might be a single technique being used. However, the considerable heterogeneity in methods suggests that an optimum method of achieving unconsciousness remains undefined. In voluntary assisted dying (in some US states and European countries), the common method to induce unconsciousness appears to be self-administered barbiturate ingestion, with death resulting slowly from asphyxia due to cardiorespiratory depression. Physician-administered injections (a combination of general anaesthetic and neuromuscular blockade) are an option in Dutch guidelines. Hypoxic methods involving helium rebreathing have also been reported. The method of capital punishment (USA) resembles the Dutch injection technique, but specific drugs, doses and monitoring employed vary. However, for all these forms of assisted dying, there appears to be a relatively high incidence of vomiting (up to 10%), prolongation of death (up to 7 days), and re-awakening from coma (up to 4%), constituting failure of unconsciousness. This raises a concern that some deaths may be inhumane, and we have used lessons from the most recent studies of accidental awareness during anaesthesia to describe an optimal means that could better achieve unconsciousness. We found that the very act of defining an 'optimum' itself has important implications for ethics and the law.

Patient satisfaction with anaesthesia care: development of a psychometric questionnaire and benchmarking among six hospitals in Switzerland and Austria.

BACKGROUND: We describe the development and comparison of a psychometric questionnaire on patient satisfaction with anaesthesia care among six hospitals. METHODS: We used a rigorous protocol: generation of items, construction of the pilot questionnaire, pilot study, statistical analysis (construct validity, factor analysis, reliability analysis), compilation of the final questionnaire, main study, repeated analysis of construct validity and reliability. We compared the mean total problem score and the scores for the dimensions: 'Information/Involvement in decision-making', and 'Continuity of personal care by anaesthetist'. The influence of potential confounding variables was tested (multiple linear regression). RESULTS: The average problem score from all hospitals was 18.6%. Most problems are mentioned in the dimensions 'Information/Involvement in decision-making' (mean problem score: 30.9%) and 'Continuity of personal care by anaesthetist' (mean problem score: 32.2%). The overall assessment of the quality of anaesthesia care was good to excellent in 98.7% of cases. The most important dimension was 'Information/Involvement in decision-making'. The mean total problem score was significantly lower for two hospitals than the total mean for all hospitals (significantly higher at two hospitals) (P<0.05). Amongst the confounding variables considered, age, sex, subjective state of health, type of anaesthesia and level of education had an influence on the total problem score and the two dimensions mentioned. There were only marginal differences with and without the influence of the confounding variables for the different hospitals. CONCLUSIONS: A psychometric questionnaire on patient satisfaction with anaesthesia care must cover areas such as patient information, involvement in decision-making, and contact with the anaesthetist. The assessment using summed scores for dimensions is more informative than a global summed rating. There were significant differences between hospitals. Moreover, the high problem scores indicate a great potential for improvement at all hospitals.

Validation of a simple algorithm for tracheal intubation: daily practice is the key to success in emergencies--an analysis of 13,248 intubations.

A fundamental skill of the anesthesiologist is airway management. We validated a simple endotracheal intubation algorithm with a large proportion of fiberoptic tracheal intubations used for years in daily practice. Over 2 yr, 13,248 intubations (>90% of all intubations, including obstetrics and ear, nose, and throat patients) in a heterogeneous patient population at our acute care hospital were evaluated prospectively. About 80 physician and nurse anesthetists were involved. Once the indication for intubation (oral or nasal) was established, the first step was to choose between the primary conventional technique (laryngoscope with Macintosh blades) and the primary fiberoptic technique. For the conventional technique, a well defined procedure had to be followed (maximum of two attempts at intubation; if unsuccessful, switch to secondary oral fiberoptic intubation). For the primary fiberoptic technique, the anesthesiologist had to decide between nasotracheal intubation in awake patients and oral intubation in anesthetized patients. Fiberoptics were used for 13.5% of the intubations. By following our algorithm, intubation failed in 6 out of 13,248 cases (0.045%; 95% confidence interval 0.02%-0.11%). We demonstrate that a simple algorithm for endotracheal intubation, basically limited to fiberoptics as the only aid, is successful in daily practice. Only methods that are practiced daily can be used successfully in emergencies.

Preoperative values of molecular coagulation markers identify patients at low risk for intraoperative haemostatic disorders and excessive blood loss.

Conventional laboratory investigations of haemostasis like prothrombin time and activated partial thromboplastin time are not useful in predicting and managing intra-operative bleeding complications. In order to establish a possible "perioperative reference range" for thrombin generation prothrombin fragment F1+2 (F1+2) and fibrin degradation (D-dimer) markers, we measured F1+2 and D-dimer concentrations before surgery (but after induction of anaesthesia), 30 minutes into surgery, 10 minutes after the event expected to induce the maximal activation of the haemostatic systems, 90 minutes after surgery and on postoperative days 1 and 2 in 226 consecutive patients. Samples were collected from arterial lines. Twenty patients developed a clinically defined, intraoperative disorder of haemostasis, 206 did not. Patients with an intraoperative disorder of haemostasis had significantly higher preoperative F1+2 and D-dimer concentrations. Preoperative values for F1+2 and D-dimer concentrations above the 75th percentile of patients without an intraoperative disorder of haemostasis indicated a 2.70 to 2.88 fold risk of developing an intraoperative disorder of haemostasis (odds ratios were 3.04, 3.12 and 3.29 for D-dimer, ELISA, F1+2, and D-dimer latex tests, respectively with 95% confidence intervals from 1.20 to 8.46) with negative predictive values of 94%, but positive predictive values of only 16% to 26%. These data suggest that preoperative determination of molecular markers might be helpful in identifying a group of patients at high risk for intraoperative disorder of haemostasis by exclusion of low risk patients. Validation of such an approach requires a prospective trial.

[The difficult intubation. The value of BURP and 3 predictive tests of difficult intubation]. / Die schwierige Intubation. Der Nutzen von BURP und die Aussagekraft von Prädiktoren.

UNLABELLED: The value of BURP (= backwards-upwards-rightwards-pressure of the larynx) was tested as a improvement of the visualisation of the larynx. Simultaneously we wanted to assess the value of different predictive tests of a difficult intubation, which are easy to perform as bedside tests. PATIENTS AND MATERIAL: 1993 patients of all different surgical clinics in a tertiary care hospital in Switzerland were tested, the complete anaesthesiological staff was involved. We registered the original Mallampati classes, the thyromental distances of Patil and Frerk and the difference of the jugulomental distances in maximally reclined and neutral head position according to Chow. Every anaesthetist also noted his personal, subjective opinion of a possible difficult intubation. Under optimal conditions for intubation we assessed the grade of laryngoscopy according to Wilson and applied BURP if the grade was 3 or higher. Both laryngoscopic grades and the difficulty of intubation were noted. RESULTS: In our study we found 12.5% awkward (Wilson G3-G5) and 4.7% difficult (Wilson G4-G5) laryngoscopies. These could be changed with BURP into 5.0% and 1.9% respectively. With BURP we found 1.8% of difficult intubations. During our study we did not find any patients, whom we could not intubate either with a mandrin inside the tube or with help of the fiberoptic. The relation between sensitivity and specificity was in all single predictors and in two combinations very low. Our personal subjective predictions proofed to be better, but the rate of false negatives was too high for clinical use. CONCLUSION: BURP is a valuable method for rendering the majority of difficult laryngoscopies into easy ones. It is very easy to learn and does not need any additional equipment. Three commonly used and recommended predictive tests of the difficult intubation proofed to be of little use in clinical practice.

[Perioperative myocardial infarction and cardiac complications after noncardiac surgery in patients with prior myocardial infarction. I. Clinical data and diagnosis, incidence]. / Perioperativer Myokardinfarkt und weitere kardiale Komplikationen nach nichtkardialen Wahloperationen bei Patienten nach Myokardinfarkt. I: Klinische Daten und Diagnostik, Inzidenz.

UNLABELLED: Patients with a prior myocardial infarction (MI) have a high risk of perioperative reinfarction compared with the normal population (5%-8% vs. 0.1%-0.7%) [10]. According to Rao [13], a reduction of this risk is possible when patients are monitored invasively and all haemodynamic parameters are kept within the physiological range. In most institutions it is not feasible to treat patients as Rao recommended: this would overstrain both hospital structure and financial resources. We studied the incidence of perioperative MI and other cardiac events in patients with prior MI. During the study period the anaesthesia and intensive care methods of our institution were neither changed nor influenced. In addition to this clinical evaluation, we performed perioperative Holter electrocardiographic monitoring and measured serum levels of the recently introduced marker troponin T (parts II and III). METHODS: Institutional informed consent was obtained. The study was planned prospectively. All patients with prior MI (156) and/or coronary artery bypass grafting (CABG) (4) who were scheduled for elective noncardiac surgery between April 1992 and March 1993 were included. The following information was acquired and tabulated: age, sex, body weight, preoperative risk factors, ASA classification, preoperative blood pressure, pulse rate, and ECG (interpreted by an independent cardiologist), serum electrolytes, haemoglobin, creatine kinase (CK), CKMB faction, creatinine. Preoperative regular medications, type of anaesthesia, type, site, and duration of surgery, and intraoperative haemodynamic changes were documented. The patients were divided into four groups depending on the time interval between MI and surgery (group I: 0-3 months, group II: 3-6 months, group III: > 6 months, group IV silent MI and prior CABG without infarction). We then studied the number of patients who developed a perioperative MI or died of cardiac causes within 7 postoperative days (n = 160). Because of early discharge of 21 patients, we could study the occurrence of cardiac events within 7 postoperative days in 139 patients only. Definitions of perioperative MI included [3]: changes of ST pattern (horizontal ST depression > 0.1 mV or elevation > 0.2 mV) during 30 s and longer; new T-negativation or Q-wave; pathological CKMB fraction (> or = 6% of total CK); and angina pectoris; two of these criteria were required to be positive (WHO). Definitions of cardiac events included: ischaemia: any reversible horizontal depression of the ST segment of more than 0.1 mV or any ST segment rise of more than 0.2 mV. Patients with bundle branch block (BBB) were excluded; angina pectoris: any chest pain that disappered after application of nitroglycerine; arrhythmia: any change from preoperative rhythm or appearence of ventricular premature beats; and left ventricular failure: clinical and radiological signs of ventricular failure. Statistical evaluation of the demographic data was performed by the Kruskall-Wallis test; categoric variables were examined using the chi 2 test and Fisher's exact test. P values of less than 0.05 were considered significant. RESULTS: Six of the 160 patients with prior MI developed a perioperative MI (3.8%); 2 of them (33%) died of cardiac causes (3rd and 6th postoperative day). All of these patients were in groups III or IV (interval > 6 months). Forty-two patients had one or more other cardiac events; arrhythmias (22) and ischaemia (14) were most common. Intraoperative hypotension was associated with postoperative MI (5 of 58 vs. 1 of 102). Preoperative congestive heart failure (4 of 18 vs. 3 of 121) and major surgery (7 of 68 vs. 0 of 71) led more often to postoperative left ventricular failure. Patients who received beta-blocking agents preoperatively had significantly fewer ischaemic cardiac events (0 of 28 vs. 14 of 90, 21 patients excluded with BBB) but differed in mean age (67 vs. 71 years). The use of beta-blocking agents was not associated with a reducti

[Verification of the endotracheal tube placement]. / Uberprüfung der Tubuslage.

Verification of the correct position of the endotracheal tube is a daily routine task of every anaesthesiologist. Accidental intubation of the oesophagus is a very rare complication in absolute terms but still the most frequent preventable anaesthetic mishap with fatal outcome. Even the most experienced anaesthetist is not immune to this complication. Only vigilance on the part of the anaesthetist protects the patient. There is no absolutely reliable gold standard to diagnose the correct position of the tracheal tube. Visualization of the endotracheal tube between the vocal cords and a typical CO2 excretion waveform are two of the best practical signs. After every change of position of the patient, especially after flexion or extension of the head, the position of the tube must be checked again. The old aphorism is still valid: When in doubt, take it out.

[Intraoperative, direct and continuous measurement of stomach pH following pretreatment with ranitidine or sodium citrate]. / Die intraoperative, direkte und kontinuierliche pH-Messung im Magen nach Vorbehandlung mit Ranitidin oder Natriumcitrat.

We carried out continuous direct pH measurements of gastric fluid in 49 female patients pretreated with 300 mg ranitidine by mouth on the evening prior to surgery and 150 mg by mouth before the operation. A further 51 women were pretreated with 30 ml sodium citrate shortly before admission to the operating room. Twenty patients received 30 ml sodium citrate via a separate gastric tube after the first pH measurement; 22 were given no premedication. In 95% of cases, 30 ml sodium citrate was found to increase the pH to over 3.5 within 5 min; a failure rate of 5% can therefore be expected. This can be explained mainly by the failure of sodium citrate to mix thoroughly with the gastric fluid. Pretreatment with ranitidine increased the pH to over 4.0 in every case, and the pH on extubation was still over 4.0 even after delayed pH on extubation was still over 4.0 even after delayed or prolonged operations. We recommend that 30 ml sodium citrate be given shortly before the beginning of emergency obstetric operations. However, we prefer ranitidine for elective operations in patients at risk for aspiration because it increases of the gastric fluid pH to at least 4.0 in every case.

["Hepatitis" following halothane-anesthesia (author's transl)]. / "Hepatitis" nach halothananaesthesie.

"Hepatitis" following halothane-anesthesia is a rare complication, occurring once after about 2500 halothane-anaesthesias. The mortality is estimated to be 20-25%. The disease can be diagnosed by exclusion of other causes only. The differential diagnosis of postoperative jaundice is therefore briefly reviewed. Three hypotheses of possible pathogenic mechanisms are discussed, namely the theory of toxic products of the metabolism of halothane, the theory of delayed hypersensitivity to a metabolite and the theory of coincidence with preexisting unknown liver disease. None of these theories has been proved definitely. The use of halothane is contraindicated if a patient suffered from unexplained pyrexia and jaundice after a previous exposure to halothane. Gamma radiation decomposes halothane to hexachlorofluorobutene, a know hepatotoxin. The repeated use of halothane during irradiation therapy is therefore contraindicated. The risk of "hepatitis" after halothane anaesthesia increases if the patient is exposed to halothane twice within four weeks, especially if he is obese and older than 40 years. The risks and advantages of repeated halothane exposures have to be weighed against the risks of alternative techniques. The increased mortality after repeated anaesthesias within short periods of time, irrespective of the technique used, has to be considered.