Comparison of expert and novice performance of a simulated transesophageal echocardiography examination.

INTRODUCTION: Training in transesophageal echocardiography (TEE) requires a significant commitment of time and resources on behalf of the trainees and the instructors. Training opportunities may be limited in the busy clinical environment. Medical simulation has emerged as a complementary means by which to develop clinical skills. Transesophageal echocardiography simulators have been commercially available for several years, yet their ability to distinguish experts from novices has not been demonstrated. We used a standardized assessment tool to distinguish experts from novices using a commercially available TEE simulator. METHODS: Anesthesiologists certified in advanced perioperative TEE and anesthesiology resident physicians were recruited into the expert and novice cohorts, respectively. The cohorts were recruited from 2 academic medical centers. The novice cohort received a structured introduction to the basic TEE examination. Both cohorts then proceeded to perform a basic TEE examination involving normal cardiac anatomy, which was evaluated by blinded raters using a standardized assessment tool. RESULTS: The expert cohort consistently demonstrated the ability to obtain standard TEE imaging views in less time and more accurately than the novice cohort during the course of a simulated TEE examination. CONCLUSIONS: A simulated transesophageal examination of normal cardiac anatomy in concert with a standardized assessment tool permits ample discrimination between expert and novice echocardiographers as defined for this investigation. Future research will examine in detail the role echocardiography simulators should play during echocardiography training including assessment of training level.

Simulation-based assessment and retraining for the anesthesiologist seeking reentry to clinical practice: a case series.

BACKGROUND: Established models for assessment and maintenance of competency in anesthesiology may not be adequate for anesthesiologists wishing to reenter practice. The authors describe a program developed in their institution incorporating simulator-based education, to help determine competency in licensed and previously licensed anesthesiologists before return to practice. METHODS: The authors have used simulation for assessment and retraining at their institution since 2002. Physicians evaluated by the authors' center undergo an adaptable 2-day simulation-based assessment conducted by two board-certified anesthesiologists. A minimum of three cases are presented on each day, with specific core competencies assessed, and participants complete a standard Clinical Anesthesia Year 3 level anesthesia knowledge test. Participants are debriefed extensively and retraining regimens are designed, where indicated, consisting of a combination of simulation and operating-room observership. RESULTS: Twenty anesthesiologists were referred to the authors' institution between 2002 and 2012. Fourteen participants (70%) were in active clinical practice 1 yr after participation in the authors' program, five (25%) were in supervised positions, and nine (45%) had resumed independent clinical practice. The reasons of participants not in practice were personal (1 participant) and medico-legal (3 participants); two participants were lost to follow-up. Two of 14 physicians, who were formally assessed in the authors' program, were deemed likely unfit for safe return to practice, irrespective of further training. These physicians were unavailable for contact 1 yr after assessment. CONCLUSION: Anesthesiologists seeking to return to active clinical status are a heterogeneous group. The simulated environment provides an effective means by which to assess baseline competency and also a way to retrain physicians.

Role of simulation in U.S. physician licensure and certification.

The evolution of simulation from an educational tool to an emerging evaluative tool has been rapid. Physician certification has a long history and serves an important role in assuring that practicing physicians are competent and capable of providing a high level of safe care to patients. Traditional assessment methods have relied mostly on multiple-choice exams or continuing medical education exercises. These methods may not be adequate to assess all competencies necessary for excellence in medical practice. Simulation enables assessment of physician competencies in real time and represents the next step in physician certification in the modern age of healthcare.

A freshwater cyanophage whose genome indicates close relationships to photosynthetic marine cyanomyophages.

Bacteriophage S-CRM01 has been isolated from a freshwater strain of Synechococcus and shown to be present in the upper Klamath River valley in northern California and Oregon. The genome of this lytic T4-like phage has a 178,563 bp circular genetic map with 297 predicted protein-coding genes and 33 tRNA genes that represent all 20-amino-acid specificities. Analyses based on gene sequence and gene content indicate a close phylogenetic relationship to the 'photosynthetic' marine cyanomyophages infecting Synechococcus and Prochlorococcus. Such relatedness suggests that freshwater and marine phages can draw on a common gene pool. The genome can be considered as being comprised of three regions. Region 1 is populated predominantly with structural genes, recognized as such by homology to other T4-like phages and by identification in a proteomic analysis of purified virions. Region 2 contains most of the genes with roles in replication, recombination, nucleotide metabolism and regulation of gene expression, as well as 5 of the 6 signature genes of the photosynthetic cyanomyophages (hli03, hsp20, mazG, phoH and psbA; cobS is present in Region 3). Much of Regions 1 and 2 are syntenic with marine cyanomyophage genomes, except that a segment encompassing Region 2 is inverted. Region 3 contains a high proportion (85%) of genes that are unique to S-CRM01, as well as most of the tRNA genes. Regions 1 and 2 contain many predicted late promoters, with a combination of CTAAATA and ATAAATA core sequences. Two predicted genes that are unusual in phage genomes are homologues of cellular spoT and nusG.

The influence of simulation-based physiology labs taught by anesthesiologists on the attitudes of first-year medical students towards anesthesiology.

BACKGROUND: The development of medical students' perceptions of different medical specialties is based on many factors and influences their career choices and appreciation of other practitioners' knowledge and skills. The goal of this study was to determine if participation in a series of anesthesiologist-run, simulation-based physiology labs changed first year medical students' perceptions of anesthesiologists. METHODS: One hundred first-year medical students were surveyed at random three months before completion of a simulation-based physiology lab run by anesthesiologists. All participants received the same survey instrument, which employed a 5-point Rating Scale to rate the appropriateness of several descriptive terms as they apply to a particular specialist or specialty. A post-simulation survey was performed to track changes in attitudes. RESULTS: Response rates to the survey before and after the simulation labs were 75% and 97% (ofthe initial cohort responding), respectively. All students who filled out the post-simulation surveys had been exposed to anesthesiologists in the prior three months whereas none had interacted with surgeons in the interim. Nearly all had interacted with internal medicine specialists in that time period. No changes in the medical students' perceptions of surgeons or internal medicine specialists were evident. Statistically significant changes were found for most descriptors of anesthesiologists, with a trend towards a more favorable perception after the simulation program. CONCLUSIONS: Using a survey instrument containing descriptors of different medical specialists and specialties, we found an improved attitude towards anesthesiology after medical students participated in an anesthesiologist-run simulation-based physiology lab series. Given the importance of providing high quality medical education and attracting quality applicants to the field, integrati-on of anesthesiology staff into medical student courses at the non-clinical level appears useful.

Population turnover in a Microcystis bloom results in predominantly nontoxigenic variants late in the season.

Surface samples of the 2007 Microcystis bloom occurring in Copco Reservoir on the Klamath River in Northern California were analyzed genetically by sequencing clone libraries made with amplicons at three loci: the internal transcribed spacer of the rRNA operon (ITS), cpcBA, and mcyA. Samples were taken between June and October, during which time two cell count peaks occurred, in mid-July and early September. The ITS and cpcBA loci could be classified into four or five allele groups, which provided a convenient means for describing the Microcystis population and its changes over time. Each group was numerically dominated by a single, highly represented sequence. Other members of each group varied by changes at 1 to 3 nucleotide positions, while groups were separated by up to 30 nucleotide differences. As deduced by a partial sampling of the clone libraries, there were marked population turnovers during the season, indicated by changes in allele composition at both the ITS and cpcBA loci. Different ITS and cpcBA genotypes appeared to be dominant at the two population peaks. Toxicity (amount of microcystin per cell) and toxigenic potential (mcyB copy number) were lower during the second peak, and the mcyB copy number fell further as the bloom declined.

Effect of theophylline and aminophylline on transmitter release at the mammalian neuromuscular junction is not mediated by cAMP.

1. Theophylline and aminophylline have been widely used as inhibitors of phosphodiesterase when examining the role of cAMP in regulating cell function. In reality, however, these phosphodiesterase inhibitors may have additional sites of action that could complicate the interpretation of the results. These additional sites of action could include antagonism of inhibitory adenosine autoreceptors and release of intracellular calcium. The purpose of the present study was to determine which of the above three is the primary mechanism by which theophylline and aminophylline affect transmitter release at the mammalian neuromuscular junction. 2. Quantal release measurements were made using intracellular recording techniques. A variety of drugs were used to elucidate this pathway. Isoproterenol, an adenylate cyclase activator, was first used to establish the effect of enhanced levels of cAMP. Theophylline application on its own or in the presence of a drug combination that blocked the adenosine receptor and phosphodiesterase pathways caused significant release depression, opposite to what is expected if it was functioning to enhance cAMP levels. However, when applied in the presence of a drug combination that blocked the adenosine receptor, phosphodiesterase and intracellular ryanodine calcium pathways, theophylline was unable to depress release. Therefore, it was concluded that the major mechanism of action of theophylline is depression of transmitter release by causing the release of intracellular calcium. 3. Aminophylline application alone resulted in a significant enhancement of release. However, when coupled with an adenosine receptor blocker, the ability of aminophylline to enhance transmitter release was blocked, suggesting that its dominant mechanism of action is adenosine receptor inhibition. 4. Taken together, these results indicate that the use of theophylline and aminophylline is inappropriate when examining the role of cAMP at the mammalian neuromuscular junction.

Adenosine inhibits N-type calcium channels at the rat neuromuscular junction.

1. In earlier studies, it has been reported that under in vitro conditions transmitter release at the rat neuromuscular junction is normally suppressed due to the effect of adenosine release from the isolated tissue. In the present study we wanted to determine whether this action may involve the inhibition of calcium influx through adenosine-sensitive calcium channels. 2. In order to test this hypothesis, we examined the role of N-type calcium channels in regulating nerve-evoked transmitter release by using the N-type calcium channel-specific blocker omega-conotoxin GVIA (CTX). In order to control the inhibitory action of adenosine, we also used the adenosine A1 receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX). We tested the effect of blocking N-type calcium channels with CTX in the presence and absence of DPCPX. We examined the effects of these drugs on quantal transmitter release in the transected preparation of the phrenic nerve-hemidiaphragm of the rat using intracellular recording techniques. 3. At 10 nmol/L, CTX alone had no effect on nerve-evoked transmitter release; however, in the presence of 0.1 micro mol/L DPCPX, CTX significantly depressed nerve-evoked transmitter release. 4. These data support the view that adenosine inhibits nerve-evoked transmitter release by inhibiting N-type calcium channels on nerve terminals.