Correction to: Predictive validity of a novel non-invasive estimation of effective shunt fraction in critically ill patients.

An amendment to this paper has been published and can be accessed via the original article.

The "Key" or "Critical" Portions of an Operation: Understanding Attending Supervision and Resident Autonomy From a Legal Perspective.

OBJECTIVE: To obtain a legal understanding of the "key" or "critical" portions of an operation, pertaining to attending supervision, resident autonomy, and patient safety. DESIGN: Snowball sampling, a subset of purposive sampling, was used to develop a population of 47 risk managers and legal counsel, who were given an online, qualitative questionnaire. Interpretive description was used to analyze qualitative data. Individual responses were coded with simultaneous categorization and assessment of underlying relationships. SETTING: Online, qualitative questionnaire. PARTICIPANTS: Hospital risk managers and legal counsel from across the United States. RESULTS: Overall, 25 of 47 (53%) risk managers completed the survey. Qualitative responses could be organized into 3 major themes (1) variation in the definition of "key" or "critical" portions of an operation, (2) differing expectations of attending supervision and resident autonomy, and (3) the need for clear communication and trust among attendings, residents, and patients. CONCLUSIONS: Among risk managers, the primary liaisons between surgeons and patients in malpractice litigation, there is widespread variation in understanding the "key" and "critical" portions of an operation and the dynamic between appropriate attending supervision and resident autonomy. Better collaboration and transparency between surgeons and legal experts are required to facilitate a shared mental model regarding attending supervision and resident autonomy.

Predictive validity of a novel non-invasive estimation of effective shunt fraction in critically ill patients.

BACKGROUND: Accurate measurement of pulmonary oxygenation is important for classification of disease severity and quantification of outcomes in clinical studies. Currently, tension-based methods such as P/F ratio are in widespread use, but are known to be less accurate than content-based methods. However, content-based methods require invasive measurements or sophisticated equipment that are rarely used in clinical practice. We devised two new methods to infer shunt fraction from a single arterial blood gas sample: (1) a non-invasive effective shunt (ES) fraction calculated using a rearrangement of the indirect Fick equation, standard constants, and a procedural inversion of the relationship between content and tension and (2) inferred values from a database of outputs from an integrated mathematical model of gas exchange (DB). We compared the predictive validity-the accuracy of predictions of PaO2 following changes in FIO2-of each measure in a retrospective database of 78,159 arterial blood gas (ABG) results from critically ill patients. RESULTS: In a formal test set comprising 9,635 pairs of ABGs, the median absolute error (MAE) values for the four measures were as follows: alveolar-arterial difference, 7.30 kPa; PaO2/FIO2 ratio, 2.41 kPa; DB, 2.13 kPa; and ES, 1.88 kPa. ES performed significantly better than other measures (p < 10-10 in all comparisons). Further exploration of the DB method demonstrated that obtaining two blood gas measurements at different FIO2 provides a more precise description of pulmonary oxygenation. CONCLUSIONS: Effective shunt can be calculated using a computationally efficient procedure using routinely collected arterial blood gas data and has better predictive validity than other analytic methods. For practical assessment of oxygenation in clinical research, ES should be used in preference to other indices. ES can be calculated at http://baillielab.net/es .

Surgeons have an opportunity to improve teaching quality through feedback provision.

BACKGROUND: Medical student evaluations of faculty are increasingly incorporated into promotion and tenure decisions, making it imperative to understand learner perceptions of quality teaching. Prior work has shown that students value faculty responsiveness in the form of feedback, but faculty and students differ in their perceptions of what constitutes sufficient feedback. The innovative minute feedback system (MFS) can quantify responsiveness to students' feedback requests. This study assessed how feedback provision via MFS impacts teaching quality scores. MATERIALS AND METHODS: This retrospective observational study compared average faculty teaching quality scores with faculty's percentage response to student feedback requests via the MFS. The data were generated from the core surgical clerkship for third-year medical students at the University of Michigan Medical School. The relationship between average teaching quality scores and response percentage was assessed by weighted regression analysis. RESULTS: Two hundred thirty-seven medical students requested feedback via MFS, and 104 faculty were evaluated on teaching quality. The mean faculty feedback response percentage was 55.78%. The mean teaching quality score was 4.27 on a scale of 1 to 5. Teaching quality score was significantly correlated with response percentage (P < 0.001); for every 10% increase in response percentage, average teaching quality score improved by 0.075. Average teaching quality score was not significantly associated with response time (P = 0.158), gender (P = 0.407), or surgical service (P = 0.498). CONCLUSIONS: Medical students consider responsiveness to feedback requests an important component of quality teaching. Furthermore, faculty development focused on efficient and practical feedback strategies may have the added benefit of improving their teaching quality.