Validation of core competencies during residency training in anaesthesiology

Background and goal: Curriculum development for residency training is increasingly challenging in times of financial restrictions and time limitations. Several countries have adopted the CanMEDS framework for medical education as a model into their curricula of specialty training. The purpose of the present study was to validate the competency goals, as derived from CanMEDS, of the Department of Anaesthesiology and Intensive Care Medicine of the Berlin Charité University Medical Centre, by conducting a staff survey. These goals for the qualification of specialists stipulate demonstrable competencies in seven areas: expert medical action, efficient collaboration in a team, communications with patients and family, management and organisation, lifelong learning, professional behaviour, and advocacy of good health. We had previously developed a catalogue of curriculum items based on these seven core competencies. In order to evaluate the validity of this catalogue, we surveyed anaesthetists at our department in regard to their perception of the importance of each of these items. In addition to the descriptive acquisition of data, it was intended to assess the results of the survey to ascertain whether there were differences in the evaluation of these objectives by specialists and registrars

Facilitating Next-Generation Pre-Exposure Prophylaxis Clinical Trials Using HIV Recent Infection Assays: A Consensus Statement from the Forum HIV Prevention Trial Design Project

Standard-of-care HIV pre-exposure prophylaxis (PrEP) is highly efficacious, but uptake of and persistence on a daily oral pill is low in many settings. Evaluation of alternate PrEP products will require innovation to avoid the unpractically large sample sizes in noninferiority trials. We propose estimating HIV incidence in people not on PrEP as an external counterfactual to which on-PrEP incidence in trial subjects can be compared. HIV recent infection testing algorithms (RITAs), such as the limiting antigen avidity assay plus viral load used on specimens from untreated HIV positive people identified during screening, is one possible approach. Its feasibility is partly dependent on the sample size needed to ensure adequate power, which is impacted by RITA performance, the number of recent infections identified, the expected efficacy of the intervention, and other factors. Screening sample sizes to support detection of an 80% reduction in incidence for 3 key populations are more modest, and comparable to the number of participants in recent phase III PrEP trials. Sample sizes would be significantly larger in populations with lower incidence, where the false recency rate is higher or if PrEP efficacy is expected to be lower. Our proposed counterfactual approach appears to be feasible, offers high statistical power, and is nearly contemporaneous with the on-PrEP population. It will be important to monitor the performance of this approach during new product development for HIV prevention. If successful, it could be a model for preventive HIV vaccines and prevention of other infectious diseases

Comparative pharmacodynamic modeling of the electroencephalography-slowing effect of isoflurane, sevoflurane, and desflurane

BACKGROUND: The most common measure to compare potencies of volatile anesthetics is minimum alveolar concentration (MAC), although this value describes only a single point on a quantal concentration-response curve and most likely reflects more the effects on the spinal cord rather than on the brain. To obtain more complete concentration-response curves for the cerebral effects of isoflurane, sevoflurane, and desflurane, the authors used the spectral edge frequency at the 95th percentile of the power spectrum (SEF95) as a measure of cerebral effect. METHODS: Thirty-nine patients were randomized to isoflurane, sevoflurane, or desflurane groups. After induction with propofol, intubation, and a waiting period, end-tidal anesthetic concentrations were randomly varied between 0.6 and 1.3 MAC, and the EEG was recorded continuously. Population pharmacodynamic modeling was performed using the software package NONMEM. RESULTS: The population mean EC50 values of the final model for SEF95 suppression were 0.66+/-0.08 (+/- SE of estimate) vol% for isoflurane, 1.18+/-0.10 vol% for sevoflurane, and 3.48+/-0.66 vol% for desflurane. The slopes of the concentration-response curves were not significantly different; the common value was lambda = 0.86+/-0.06. The Ke0 value was significantly higher for desflurane (0.61+/-0.11 min(-1)), whereas separate values for isoflurane and sevoflurane yielded no better fit than the common value of 0.29+/-0.04 min(-1). When concentration data were converted into fractions of the respective MAC values, no significant difference of the C50 values for the three anesthetic agents was found. CONCLUSIONS: This study demonstrated that (1) the concentration-response curves for spectral edge frequency slowing have the same slope, and (2) the ratio C50(SEF95)/MAC is the same for all three anesthetic agents. The authors conclude that MAC and MAC multiples, for the three volatile anesthetics studied, are valid representations of the concentration-response curve for anesthetic suppression of SEF95.status: publishe

Meta-analysis: ventilation strategies and outcomes of the acute respiratory distress syndrome and acute lung injury.

BACKGROUND: Trials have provided conflicting results regarding the effect of different ventilatory strategies on the outcomes of patients with the acute respiratory distress syndrome (ARDS) and acute lung injury. PURPOSE: To determine whether ventilation with low tidal volume (Vt) and limited airway pressure or higher positive end-expiratory pressure (PEEP) improves outcomes for patients with ARDS or acute lung injury. DATA SOURCES: Multiple computerized databases (through March 2009), reference lists of identified articles, and queries of principal investigators. No language restrictions were applied. STUDY SELECTION: Randomized, controlled trials (RCTs) reporting mortality and comparing lower versus higher Vt ventilation, lower versus higher PEEP, or a combination of both in adults with ARDS or acute lung injury. DATA EXTRACTION: Using a standard protocol, 2 reviewer teams assessed trial eligibility and abstracted data on quality of study design and conduct, population characteristics, intervention, co-interventions, and confounding variables. DATA SYNTHESIS: 4 RCTs tested lower versus higher Vt ventilation at similar PEEP in 1149 patients, 3 RCTs compared lower versus higher PEEP at low Vt ventilation in 2299 patients, and 2 RCTs compared a combination of higher Vt and lower PEEP ventilation versus lower Vt and higher PEEP ventilation in 148 patients. Lower Vt ventilation reduced hospital mortality (odds ratio, 0.75 [95% CI, 0.58 to 0.96]; P = 0.02) compared with higher Vt ventilation at similar PEEP. Higher PEEP did not reduce hospital mortality (odds ratio, 0.86 [CI, 0.72 to 1.02]; P = 0.08) compared with lower PEEP using low Vt ventilation. Higher PEEP reduced the need for rescue therapy to prevent life-threatening hypoxemia (odds ratio, 0.51 [CI, 0.36 to 0.71]; P < 0.001) and death (odds ratio, 0.51 [CI, 0.36 to 0.71]; P < 0.001) in patients receiving rescue therapies. LIMITATIONS: Pooling according to similar ventilatory strategies resulted in few RCTs analyzed in each group. The benefit of low Vt is derived from only 1 study. CONCLUSION: Available evidence from a limited number of RCTs shows better outcomes with routine use of low Vt but not high PEEP ventilation in unselected patients with ARDS or acute lung injury. High PEEP may help to prevent life-threatening hypoxemia in selected patients

Atemarbeit bei Patienten mit und ohne chronisch-obstruktiver Lungenerkrankung unter druckunterstützter Beatmung mit geringem PEEP

Buscher H, Sydow M, Thies K-C, Zinserling J, Hinz J, Burchardi H. Atemarbeit bei Patienten mit und ohne chronisch-obstruktiver Lungenerkrankung unter druckunterstützter Beatmung mit geringem PEEP. Intensivmedizin und Notfallmedizin. 1999;36(2):197-202.The influence of pressure support of 5 and 10 cmH2O and low-level positive endexpiratory pressure (PEEP) of 5cm H2O on work of breathing (WOB) and breathing pattern was studied in 16 mechanically ventilated patients. Eight patients suffered from chronic obstructive lung disease (COPD), eight patients had no obstructive lung disease. Low-level PEEP as well as pressure support reduced the work of breathing. Combination of both measures was additively effective. PEEP of 5 cmH2O and pressure support of 10 cmH2O decreased WOB more than 50% on average. Without any pressure support more than 20% of WOB were done on the ventilator system (e.g. flow delivery, trigger mechanism etc.). By application of 10 cmH2O of pressure support this part of the work of breathing was negligible. In COPD patients an intrinsic PEEP increased the work of breathing which was counterbalanced by an external PEEP. However, our study revealed high interindividual differences in WOB. Thus, measurement of work of breathing is encouraged to optimize the ventilatory setting by individual adaptation of the PEEP and pressure support level.An 16 druckunterstützt beatmeten Patienten, davon acht mit chronisch obstruktiver Lungenerkrankung (COPD) und acht ohne obstruktive Lungenkrankheiten wurde der Einfluß eines PEEP von 5 cmH2O und einer Druckunterstützung von 5 und 10 cmH2O auf die mechanische Atemarbeit und andere atemmechanische Meßgrößen untersucht. Sowohl durch PEEP wie auch durch Druckunterstützung konnte die Atemarbeit gesenkt werden. Die Kombination beider Maßnahmen wirkte additiv. Ein PEEP von 5 cm H2O und eine Druckunterstützung von 10 cmH2O senkte die Atemarbeit im Durchschnitt um mehr als 50% in beiden Patientengruppen. Ohne Druckunterstützung leistet der Patienten mehr als 20% seiner gesamten Atemarbeit auf Widerstände des Beatmungssystems (z.B. Gasflußanlieferung, Triggermechanismus etc.). Durch 10 cmH2O Druckunterstützung war dieser Atemarbeitsanteil nahezu kompensiert und zu vernachlässigen. Ein bestehender intrinsischer PEEP bei COPD-Patienten erhöhte die Atemarbeit und wurde durch Applikation eines externen PEEP vermindert. Die Höhe der Atemarbeit war in unserer Untersuchung interindividuell sehr unterschiedlich. Daher erscheint uns eine individuelle Anpassung von PEEP und Druckunterstützung anhand der gemessenen Atemarbeit sinnvoll

The Entropy Module and Bispectral Index as guidance for propofol-remifentanil anaesthesia in combination with regional anaesthesia compared with a standard clinical practice group.

Item does not contain fulltextThis study was designed to investigate the impact of the Entropy Module and Bispectral Index (BIS) monitoring on drug consumption and recovery times compared with standard anaesthetic practice in patients undergoing orthopaedic surgery using a combination of regional and general anaesthesia as performed by an experienced anaesthesiologist. We hypothesised that electroencephalogram monitoring would lead to a lower drug consumption as well as shorter recovery times. With institutional review board approval and written informed consent, 90 adult patients undergoing surgery to the upper or lower extremity received regional anaesthesia for post- and intraoperative pain control and were randomised to receive general anaesthesia by propofol/remifentanil infusion controlled either solely by clinical parameters or by targeting Entropy or BIS values of 50. Recovery times and drug consumption were recorded. Data from 79 patients were analysed. Compared with standard practice, patients with Entropy or BIS monitoring showed a similar propofol consumption (standard practice 101 +/- 22 microg/kg/minute, Entropy 106 +/- 24 microg/kg/minute, BIS 104 +/- 20 microg/kg/minute) and showed similar Aldrete scores (10/10) one minute after extubation: 9.1 +/- 0.3, 9.2 +/- 0.6 and 9.3 +/- 0.5, respectively. Time points of extubation were 7.3 +/- 2.9 minutes, 9.2 +/- 3.9 minutes and 6.8 +/- 2.9 minutes, respectively, demonstrating a significant difference between Entropy and BIS (P = 0.023). Compared with standard practice, targeting an Entropy or BIS value of 50 did not result in a reduction of propofol consumption during general anaesthesia combined with regional anaesthesia as performed by an experienced anaesthesiologist in orthopaedic patients.1 januari 201