High-sensitivity cardiac troponin T in young, healthy adults undergoing non-cardiac surgery.

BACKGROUND: It is unclear if isolated postoperative cardiac-troponin elevation, often referred to as myocardial injury, represents a pathological event, as control studies in otherwise healthy adults are lacking. METHODS: In this single-centre prospective observational cohort study, serial high-sensitivity cardiac troponin T (hscTnT) plasma concentrations were obtained from young, healthy adults undergoing elective orthopaedic surgery at three time points: before operation, 2-6 h, and 18-30 h after surgery. End points were hscTnT increases after surgery: ≥20% (exceeding analytical variability), ≥50% (exceeding short-term biological variability), and ≥85% (exceeding long-term biological variability). The secondary end point was myocardial injury, defined as new postoperative hscTnT elevation >99th % upper reference limit (URL) (women >10 ng litre-1; men >15 ng litre-1). RESULTS: Amongst the study population (n=95), no hscTnT increase ≥20% was detected in 68 patients (73%). A hscTnT increase between 20% and 49% was observed in 17 patients (18%), 50-84% in seven patients (7%), and ≥85% in three patients (3%). Twenty patients (21%) had an absolute ΔhscTnT between 0 and 2 ng litre-1, 12 patients (13%) between 2 and 4 ng litre-1, three patients between 4 and 6 ng litre-1, and one patient (1%) between 6 and 8 ng litre-1. Myocardial injury (new hscTnT elevation >99th%) was diagnosed in one patient (1%). The median hscTnT concentrations did not increase after operation, and were 4 (3.9-5, inter-quartile range) ng litre-1 at baseline, 4 (3.9-5) ng litre-1 at 2-6 h after surgery, and 4 (3.9-5) ng litre-1 on postoperative day 1. CONCLUSIONS: One in four young adult patients without known cardiovascular disease developed a postoperative hscTnT increase, but without exceeding the 99th% URL and without evidence of myocardial ischaemia. These results may have important ramifications for the concept of postoperative myocardial injury, as they suggest that, in some patients, postoperative cardiac-troponin increases may be the result of a normal physiological process in the surgical setting. CLINICAL TRIAL REGISTRATION: NCT 02394288.

[Thermal injuries in the OEAMTC air rescue service. Epidemiological characteristics of burns/scalds in children and adults]. / Thermische Verletzungen in der ÖAMTC-Luftrettung. Einsatzcharakteristika bei Verbrennungen/Verbrühungen von Kindern und Erwachsenen.

BACKGROUND: Few data exist on the epidemiological characteristics of thermal injuries in prehospital emergency care, especially in the context of air rescue. Therefore, this study aimed to analyze the epidemiology of pediatric and adult thermal injuries in the helicopter emergency medical service (HEMS) run by the Austrian Automobile Motorcycle Touring Club (OEAMTC) air rescue service from an almost nationwide sample. METHODS: All OEAMTC-HEMS rescue missions flown for thermal injuries in 2009 were retrospectively reviewed. Primary (n=88) and secondary missions (n=17) were collated and all primary missions were analyzed in detail. RESULTS: In total 71 out of 16,100 (0.4 %) primary HEMS rescue missions were for patients suffering from burns or scalds (children n=27, adults n=44). The proportion of major burns (burns covering >20 % of the total body surface area) was 40.7 % in children and 54.5 % in adults, 44 (62 %) burn/scald injuries were related to the head/neck, 37 (52.1 %) to the upper limbs and 10 (14.1 %) to the anogenital region. More than half of the victims (63.4%) suffered potentially life-threatening injury. CONCLUSIONS: In HEMS thermal injuries are infrequent but mostly life-threatening. Differences in epidemiological characteristics of pediatric and adult burns/scalds may have important operational, training and public health implications.

A meta-analysis of CYP2D6 metabolizer phenotype and metoprolol pharmacokinetics.

Metoprolol, a commonly prescribed ß-blocker, is primarily metabolized by cytochrome P450 2D6 (CYP2D6), an enzyme with substantial genetic heterogeneity. Several smaller studies have shown that metoprolol pharmacokinetics is influenced by CYP2D6 genotype and metabolizer phenotype. To increase robustness of metoprolol pharmacokinetic estimates, a systematic review and meta-analysis of pharmacokinetic studies that administered a single oral dose of immediate-release metoprolol were performed. Pooled analysis (n = 264) demonstrated differences in peak plasma metoprolol concentration, area under the concentration-time curve, elimination half-life, and apparent oral clearance that were 2.3-, 4.9-, 2.3-, and 5.9-fold between extensive and poor metabolizers, respectively, and 5.3-, 13-, 2.6-, and 15-fold between ultrarapid and poor metabolizers (all P < 0.001), respectively. Enantiomer-specific analysis revealed genotype-dependent enantio-selective metabolism, with nearly 40% greater R- than S-metoprolol metabolism in ultrarapid and extensive metabolizers. This study demonstrates a marked effect of CYP2D6 metabolizer phenotype on metoprolol pharmacokinetics and confirms enantiomer-specific metabolism of metoprolol.

The epidemiology of amputation injuries in the Austrian helicopter emergency medical service: a retrospective, nationwide cohort study.

PURPOSE: Data on the epidemiological characteristics of traumatic amputations in prehospital emergency care, especially in the context of air rescue, are scarce. Therefore, we aimed to describe the epidemiology of total and subtotal amputation injuries encountered by the OEAMTC helicopter emergency medical service (HEMS) in Austria, based on an almost nationwide sample. METHODS: We retrospectively reviewed all HEMS rescue missions flown for amputation injuries in 2009. Only primary missions were analyzed. RESULTS: In total, 149 out of 16,100 (0.9 %) primary HEMS rescue missions were for patients suffering from amputation injuries. Among these, HEMS physicians diagnosed 63.3 % (n = 94) total and 36.9 % (n = 55) subtotal amputations, with both groups showing a predominance of male victims (male:female ratios were 8:1 and 6:1, respectively).The highest rate occurred among adults between 45 and 64 years of age (35.6 %, n = 53). The most common causes were working with a circular saw (28.9 %, n = 43) and processing wood (16.8 %, n = 25). The majority of the cases included digital amputation injuries (77.2 %, n = 115) that were mainly related to the index finger (36.2 %, n = 54). One hundred forty patients (94.0 %) showed a total GCS of more than 12. Amputations were most prevalent in rural areas (84.6 %, n = 126) and between Thursday and Saturday (55.0 %, n = 82). The replantation rate after primary air transport was low (28 %). CONCLUSIONS: In the HEMS, amputation injuries are infrequent and mostly not life-threatening. However, HEMS crews need to maintain their focus on providing sufficient and fast primary care while facilitating rapid transport to a specialized hospital. The knowledge of the epidemiological characteristics of amputation injuries encountered in the HEMS gained in this study may be useful for educational and operational purposes.

Pre-operative vitamin B infusion and prevention of nitrous oxide-induced homocysteine increase.

SUMMARY: Nitrous oxide inactivates vitamin B(12) with detrimental consequences for folate and methionine metabolism, detectable by an increase in total plasma homocysteine. We hypothesised that a pre-operative vitamin B(12) and folate infusion prevents nitrous oxide-induced homocysteine increase. Sixty-three healthy patients having elective surgery were randomly allocated to receive either B-vitamin plus nitrous oxide; placebo plus nitrous oxide or placebo plus air. Fifty-nine patients completed the study. After intravenous B-vitamin infusion, plasma vitamin B(12) and folate concentrations increased 35-fold and 12-fold, respectively, on the first postoperative measurement. Patients who received B-vitamins developed a similar increase (18%) in homocysteine after nitrous oxide (1.9 micromolxl(-1); 95% CI 0.2-3.6 micromolxl(-1)) as those who did not (22%; 2.7 micromolxl(-1); 95% CI 0.6-4.8 micromolxl(-1)). Patients not receiving nitrous oxide had no homocysteine change (0.5 micromolxl(-1); 95% CI -0.8-1.9 micromolxl(-1)), indicating that pre-operative intravenous B-vitamins may not prevent nitrous oxide-induced hyperhomocysteinaemia.

The effects of aminophylline on bispectral index during inhalational and total intravenous anaesthesia.

Aminophylline is usually used during anaesthesia to treat bronchospasm but recent findings suggest that it can also be used to shorten recovery time after general anaesthesia. However, it is unclear whether aminophylline shows similar properties during a steady-state phase of deep surgical anaesthesia. We therefore wanted to test the hypothesis that the administration of aminophylline leads to an increase in bispectral index as a surrogate parameter suggesting a lighter plane of anaesthesia. The study was designed as a double-blind, randomised, controlled trial with two main groups (aminophylline and placebo) and two subgroups (sevoflurane and propofol). We studied 60 patients. The injection of aminophylline 3 mg x kg(-1) was associated with significant increases in bispectral index up to 10 min after its injection, while heart rate and blood pressure did not change. It appears that aminophylline has the ability to partially antagonise the sedative effects of general anaesthetics.

[Advanced Trauma Life Support--a standard of care for Germany? No substantial improvement of care can be expected]. / Advanced Trauma Life Support--ein Versorgungsstandard für Deutschland? Keine wesentliche Verbesserung der Versorgung zu erwarten.

Over the last 30 years the Advanced Trauma Life Support (ATLS) course has become the most successful training program in the world for the early care of severely injured patients. It has shaped trauma care systems in many countries and is now on the verge of being introduced into Germany by the German Society of Trauma Surgery (DGU). However, after publication of the latest edition in 2004 there are rising concerns regarding the lack of multi-disciplinarity, out-dated contents and lack of adaptability to regional needs. This article questions the beneficial effect of ATLS on the advanced German trauma care system and concludes that ATLS is not likely to improve trauma care in Germany.

Nitrous oxide (N(2)O) requires the N-methyl-D-aspartate receptor for its action in Caenorhabditis elegans.

Nitrous oxide (N(2)O, also known as laughing gas) and volatile anesthetics (VAs), the original and still most widely used general anesthetics, produce anesthesia by ill-defined mechanisms. Electrophysiological experiments in vertebrate neurons have suggested that N(2)O and VAs may act by distinct mechanisms; N(2)O antagonizes the N-methyl-d-aspartate (NMDA) subtype of glutamate receptors, whereas VAs alter the function of a variety of other synaptic proteins. However, no genetic or pharmacological experiments have demonstrated that any of these in vitro actions are responsible for the behavioral effects of either class of anesthetics. By using genetic tools in Caenorhabditis elegans, we tested whether the action of N(2)O requires the NMDA receptor in vivo and whether its mechanism is shared by VAs. Distinct from the action of VAs, N(2)O produced behavioral defects highly specific and characteristic of that produced by loss-of-function mutations in both NMDA and non-NMDA glutamate receptors. A null mutant of nmr-1, which encodes a C. elegans NMDA receptor, was completely resistant to the behavioral effects of N(2)O, whereas a non-NMDA receptor-null mutant was normally sensitive. The N(2)O-resistant nmr-1(null) mutant was not resistant to VAs. Likewise, VA-resistant mutants had wild-type sensitivity to N(2)O. Thus, the behavioral effects of N(2)O require the NMDA receptor NMR-1, consistent with the hypothesis formed from vertebrate electrophysiological data that a major target of N(2)O is the NMDA receptor.

Misuse of standard error of the mean (SEM) when reporting variability of a sample. A critical evaluation of four anaesthesia journals.

BACKGROUND: In biomedical research papers, authors often use descriptive statistics to describe the study sample. The standard deviation (SD) describes the variability between individuals in a sample; the standard error of the mean (SEM) describes the uncertainty of how the sample mean represents the population mean. Authors often, inappropriately, report the SEM when describing the sample. As the SEM is always less than the SD, it misleads the reader into underestimating the variability between individuals within the study sample. METHODS: The aim of this study was to evaluate the frequency of inappropriate use of the SEM in four leading anaesthesia journals in 2001. The journals were searched manually for descriptive statistics reporting either the mean (SD) or the mean (SEM), and inappropriate use of the SEM was noted. RESULTS: In 2001, all four anaesthesia journals published articles that used the SEM incorrectly: Anesthesia & Analgesia 27.7%, British Journal of Anaesthesia 22.6%, Anesthesiology 18.7% and European Journal of Anaesthesiology 11.5%. Laboratory reports and clinical studies were equally affected, except for Anesthesiology where 90% were basic science reports. CONCLUSIONS: One in four articles (n=198/860, 23%) published in four anaesthesia journals in 2001 inappropriately used the SEM in descriptive statistics to describe the variability of the study sample. Anaesthesia journals are encouraged to provide clearer statistical guidelines on how to report data variability in descriptive statistics.

[Pediatric emergencies. An epidemiologic study of mobile care units in Innsbruck]. / Kindernotfälle im Notarztdienst. Eine epidemiologische Studie am Notarztwagen Innsbruck.

OBJECTIVES: We studied the epidemiology and outcome of prehospital pediatric emergencies treated by a physician-staffed mobile intensive care unit (MICU). METHODS: A 3-year retrospective analysis for the period 1991-1993. RESULTS: Children under the age of 15 years comprised 5.1% of the patients treated by the MICU (372/7423), 87.4% of whom were not in a life-threatening condition. The most common emergencies were: trauma (30.4%), febrile seizure (27.7%), and subglottal laryngitis (12.6%). In 44.6% of cases there was no medical indication for the MICU. Intubation at the scene was required by 17 patients (4.6%), and 11 (3.0%) underwent cardiopulmonary resuscitation following prehospital cardiac arrest; two children were successfully resuscitated but died in hospital. A total of 217 (61.3%) were admitted to the ward, 9 of these to a critical care unit. The average length of stay was 4.9 days, and 94.5% of patients were discharged in good health. CONCLUSION: Prehospital pediatric emergencies are rare and seldom life-threatening. Continuing education in pediatric emergency care is important for emergency physicians.

Sevoflurane and mivacurium in a patient with Huntington's chorea.

There is little experience of anaesthesia for patients with Huntington's chorea. These patients have an increased risk of intraoperative complications such as pulmonary aspiration. We present the successful anaesthetic management of a 17-yr-old patient suffering from Huntington's chorea requiring urgent appendectomy. After rapid-sequence induction with thiopental 400 mg and succinylcholine 100 mg, anaesthesia was maintained with sevoflurane. For maintenance of neuromuscular blockade mivacurium 10 mg was administered and repeated 15 min later. Except for a short episode of postoperative shivering, the perioperative course was uneventful. Sevoflurane and mivacurium were used safely and effectively in this patient.