Recent Publications by CFE Educators

CONTEXT

The handover represents a high-risk event in which errors are common and lead to patient harm. A better understanding of the cognitive mechanisms of handover errors is essential to improving handover education and practice.

OBJECTIVES

This paper reports on an experiment conducted to study the effects of learner knowledge, case complexity (i.e. cases with or without a clear diagnosis) and their interaction on handover accuracy and cognitive load.

METHODS

Participants were 52 Dutch medical students in Years 2 and 6. The experiment employed a repeated-measures design with two explanatory variables: case complexity (simple or complex) as the within-subject variable, and learner knowledge (as indicated by illness script maturity) as the between-subject covariate. The dependent variables were handover accuracy and cognitive load. Each participant performed a total of four simulated handovers involving two simple cases and two complex cases.

RESULTS

Higher illness script maturity predicted increased handover accuracy (p  0.001) and lower cognitive load (p = 0.007). Case complexity did not independently affect either outcome. For handover accuracy, there was no interaction between case complexity and illness script maturity. For cognitive load, there was an interaction effect between illness script maturity and case complexity, indicating that more mature illness scripts reduced cognitive load less in complex cases than in simple cases.

CONCLUSIONS

Students with more mature illness scripts performed more accurate handovers and experienced lower cognitive load. For cognitive load, these effects were more pronounced in simple than complex cases. If replicated, these findings suggest that handover curricula and protocols should provide support that varies according to the knowledge of the trainee.

Necrotizing fasciitis is a rare but serious disease, and early diagnosis is essential to reducing its substantial morbidity and mortality. The 2 cases presented show that the key clinical and radiographic features of necrotizing fasciitis exist along a continuum of severity at initial presentation; thus, this diagnosis should not be prematurely ruled out in cases that do not show the dramatic features familiar to most clinicians. Although computed tomography and magnetic resonance imaging are considered the most effective imaging modalities, the cases described here illustrate how sonography should be recommended as an initial imaging test to make a rapid diagnosis and initiate therapy.

Alpha oscillations (7-14Hz) are modulated in response to visual temporal and spatial cues. However, the neural response to alerting cues is less explored, as is how this response is affected by healthy aging. Using scalp EEG, we examined how visual cortical alpha activity relates to working memory performance. Younger (20-30 years) and older (60-70 years) participants were presented with a visual alerting cue uninformative of the position or size of a lateralized working memory array. Older adults showed longer response times overall and reduced accuracy when memory load was high. Older adults had less consistent cue-evoked alpha phase resetting than younger adults, which predicted worse performance. Alpha phase prior to memory array presentation predicted response time, but the relationship between phase and response time was weaker in older adults. These results suggest that changes in alpha phase dynamics, especially prior to presentation of task-relevant stimuli, potentially contribute to age-related cognitive decline.

UNLABELLED

The presence of an intrahepatic cholangiocarcinoma (iCCA) in a cirrhotic liver is a contraindication for liver transplantation in most centers worldwide. Recent investigations have shown that "very early" iCCA (single tumors ≤2 cm) may have acceptable results after liver transplantation. This study further evaluates this finding in a larger international multicenter cohort. The study group was composed of those patients who were transplanted for hepatocellular carcinoma or decompensated cirrhosis and found to have an iCCA at explant pathology. Patients were divided into those with "very early" iCCA and those with "advanced" disease (single tumor >2 cm or multifocal disease). Between January 2000 and December 2013, 81 patients were found to have an iCCA at explant; 33 had separate nodules of iCCA and hepatocellular carcinoma, and 48 had only iCCA (study group). Within the study group, 15/48 (31%) constituted the "very early" iCCA group and 33/48 (69%) the "advanced" group. There were no significant differences between groups in preoperative characteristics. At explant, the median size of the largest tumor was larger in the "advanced" group (3.1 [2.5-4.4] versus 1.6 [1.5-1.8]). After a median follow-up of 35 (13.5-76.4) months, the 1-year, 3-year, and 5-year cumulative risks of recurrence were, respectively, 7%, 18%, and 18% in the very early iCCA group versus 30%, 47%, and 61% in the advanced iCCA group, P = 0.01. The 1-year, 3-year, and 5-year actuarial survival rates were, respectively, 93%, 84%, and 65% in the very early iCCA group versus 79%, 50%, and 45% in the advanced iCCA group, P = 0.02.

CONCLUSION

Patients with cirrhosis and very early iCCA may become candidates for liver transplantation; a prospective multicenter clinical trial is needed to further confirm these results. (Hepatology 2016;64:1178-1188).

OBJECTIVE

To compare the effect of complete transection (tSCI) and contusion spinal cord injury (cSCI) on bladder function and bladder wall structure in rats.

MATERIALS AND METHODS

A total of 30 female Sprague-Dawley rats were randomly divided into three equal groups: an uninjured control, a cSCI and a tSCI group. The cSCI group underwent spinal cord contusion, while the tSCI group underwent complete spinal cord transection. At 6 weeks post-injury, 24-h metabolic cage measurement and conscious cystometry were performed.

RESULTS

Conscious cystometry analysis showed that the cSCI and tSCI groups had significantly larger bladder capacities than the control group. The cSCI group had significantly more non-voiding detrusor contractions than the tSCI group. Both injury groups had more non-voiding contractions compared with the control group. The mean threshold pressure was significantly higher in the tSCI group than in the control and cSCI groups. The number of voids in the tSCI group was lower compared with the control group. Metabolic cage analysis showed that the tSCI group had larger maximum voiding volume as compared with the control and cSCI groups. Vesicular acetylcholine transporter/smooth muscle immunoreactivity was higher in the control than in the cSCI or tSCI rats. The area of calcitonin gene-related peptide staining was smaller in the tSCI group than in the control or cSCI groups.

CONCLUSIONS

Spinal cord transection and contusion produce different bladder phenotypes in rat models of SCI. Functional data suggest that the tSCI group has an obstructive high-pressure voiding pattern, while the cSCI group has more uninhibited detrusor contractions.

PURPOSE

Various cochlear dose surrogates have been reported as associated with hearing outcome in studies of stereotactic radiosurgery (SRS) for vestibular schwannomas. In this study, we investigated whether an inherent functional relationship exists among these reported surrogates.

METHODS AND MATERIALS

A cohort of 85 serial patient cases treated with single-fraction stereotactic radiosurgery from 1997 through 2013 at our institution was analyzed. For all the cases, the mean prescription dose was 12.5 ± 0.3 Gy (range, 12-13 Gy) and mean target volume 1.32 ± 1.51 mL (range, 0.80-8.77 mL). The mean cochlea volume was 0.078 ± 0.016 mL (range, 0.048-0.131 mL; median, 0.076 mL). Correlation analysis among mean cochlear dose, point maximum dose and modiolus dose was performed and also parameterized with new variables such as the effective dose radius (EDR) as derived from a general dose fall-off model.

RESULTS

Weak correlation via linear regression was found between the point maximum dose and the mean cochlear dose (R = 0.719) as well as the modiolus dose (R = 0.568). However, when parameterized with EDR, a near-perfect correlation (P .0001) via linear regression was found between the EDR for the point maximum dose and the EDR for the mean cochlear dose (R = 0.996), and with the EDR for the modiolus dose (R = 0.993). Such a result led to a functional formula relating these dose surrogates, yielding dose equivalence results such as: 12-Gy point maximum dose is equivalent to mean cochlear dose of 5.6 ± 0.1 Gy (95% confidence level), or modiolus dose of 6.0 ± 0.2 Gy (95% confidence level).

CONCLUSIONS

An inherent functional relationship was found among point maximum, modiolus, and mean cochlear doses for SRS of vestibular schwannomas. As such, clinical hearing outcome can be interchangeably analyzed or reported via any of these dose surrogates.

BACKGROUND

The reported rate of incidental parathyroidectomy (IP) during thyroid surgery is between 5.2 and 21.6 %. Current literature reports wide discrepancy in incidence, risk factors, and outcomes. Thus study was designed to address definitively the topic of IP and identify associated risk factors and clinical outcomes with this multi-institutional study.

METHODS

This retrospective cohort study included 1767 total thyroidectomies that occurred between 1995 and 2014 at two academic centers. Pathologic reports were reviewed for the presence of unintentionally removed parathyroid glands. Demographics, potential risk factors, and postoperative calcium levels were compared with matched control group. Logistic regression, t tests, and Chi squared tests were used when appropriate.

RESULTS

IP occurred in 286 (16.2 %) of thyroidectomies. Risk factors for IP were: malignancy, neck dissection, and lymph node metastases (p = 0.005, 0.001, and 0.001). Fifty-three (19.2 %) of IPs were intrathyroidal. Those with IP were more likely to have postoperative biochemical (65.6 vs. 42.0 %; p  0.001) and symptomatic (13.4 vs. 8.1 %; p = 0.044) hypocalcemia than controls. The number of parathyroids identified intraoperatively was inversely correlated with the number of parathyroid glands in the specimen (p  0.001).

CONCLUSIONS

Our findings indicate that malignancy, lymph node dissection, and metastatic nodal disease are risk factors for IP. Patients with IP were more likely to have postoperative biochemical and symptomatic hypocalcemia than controls, showing that there is a physiologic consequence to IP. Additionally, intraoperative surgeon identification of parathyroid glands results in a lower incidence of IP, highlighting the importance of awareness of parathyroid anatomy during thyroid surgery.