Preparing clinicians for practice: effectiveness and design of on-call simulation.

BACKGROUND: Final year medical students and postgraduate doctors regularly contend with feelings of under-preparedness when transitioning into new areas of clinical practice. This lack of confidence is most evident in the context of on-call work which frequently requires sound clinical prioritisation, rigorous decision making and the management of acutely unwell patients, often with reduced senior support and staffing. This has prompted the emergence of on-call simulation which seeks to enhance participant confidence in performing on-call tasks and facilitate the development of key clinical and non-technical skills. This narrative review examined the use of on-call simulation in medical student and newly qualified doctor cohorts, its effectiveness in achieving its stated outcomes and to identify novel areas for the development of existing models. METHOD: A search strategy was developed in conjunction with a specialist medical librarian. OVID Medline and Embase searches identified articles related to the use and design of on-call simulation in medical education with no restrictions placed upon date or language of publication. Key findings from articles were summarised to develop comprehensive themes for discussion. RESULTS: Twenty Three unique publications were reviewed which unanimously reported that on-call simulation had a positive effect on self-reported participant confidence in performing on-call roles. Furthermore the value on-call simulation when used as an induction activity was also evident. However, there was limited evidence around improved patient and performance outcomes following simulation. It also remains resource intensive as an educational tool and there is a distinct absence of interprofessional education in current models. CONCLUSIONS: We concluded that on-call simulation must adopt an interprofessional educational approach, incorporating other clinical roles. Further studies are needed to characterise the impact on patient outcomes. It remains highly useful as a confidence-boosting induction activity, particularly in specialities where clinical exposure is limited. Virtual and tabletop simulation formats, could potentially address the resource burden of manikin-based models, particularly with ever growing demands on medical educators and the expansion of training posts.

Role of a conserved glutamine residue in tuning the catalytic activity of Escherichia coli cytochrome c nitrite reductase.

The pentaheme cytochrome c nitrite reductase (NrfA) of Escherichia coli is responsible for nitrite reduction during anaerobic respiration when nitrate is scarce. The NrfA active site consists of a hexacoordinate high-spin heme with a lysine ligand on the proximal side and water/hydroxide or substrate on the distal side. There are four further highly conserved active site residues including a glutamine (Q263) positioned 8 A from the heme iron for which the side chain, unusually, coordinates a conserved, essential calcium ion. Mutation of this glutamine to the more usual calcium ligand, glutamate, results in an increase in the K m for nitrite by around 10-fold, while V max is unaltered. Protein film voltammetry showed that lower potentials were required to detect activity from NrfA Q263E when compared with native enzyme, consistent with the introduction of a negative charge into the vicinity of the active site heme. EPR and MCD spectroscopic studies revealed the high spin state of the active site to be preserved, indicating that a water/hydroxide molecule is still coordinated to the heme in the resting state of the enzyme. Comparison of the X-ray crystal structures of the as-prepared, oxidized native and mutant enzymes showed an increased bond distance between the active site heme Fe(III) iron and the distal ligand in the latter as well as changes to the structure and mobility of the active site water molecule network. These results suggest that an important function of the unusual Q263-calcium ion pair is to increase substrate affinity through its role in supporting a network of hydrogen bonded water molecules stabilizing the active site heme distal ligand.