Physiologic measurements of cognitive load in clinical reasoning

OBJECTIVES

Cognitive load is postulated to be a significant factor in clinical reasoning performance. Monitoring physiologic measures, such as heart rate variability (HRV) may serve as a way to monitor changes in cognitive load. The pathophysiology of why HRV has a relationship to cognitive load is unclear, but it may be related to blood pressure changes that occur in a response to mental stress.

METHODS

Fourteen residents and ten attendings from Internal Medicine wore Holter monitors and watched a video depicting a medical encounter before completing a post encounter form used to evaluate their clinical reasoning and standard psychometric measures of cognitive load. Blood pressure was obtained before and after the encounter. Correlation analysis was used to investigate the relationship between HRV, blood pressure, self-reported cognitive load measures, clinical reasoning performance scores, and experience level.

RESULTS

Strong positive correlations were found between increasing HRV and increasing mean arterial pressure (MAP) (p=0.01, Cohen's d=1.41). There was a strong positive correlation with increasing MAP and increasing cognitive load (Pearson correlation 0.763; 95 % CI [; 95 % CI [-0.364, 0.983]). Clinical reasoning performance was negatively correlated with increasing MAP (Pearson correlation -0.446; 95 % CI [-0.720, -0.052]). Subjects with increased HRV, MAP and cognitive load were more likely to be a resident (Pearson correlation -0.845; 95 % CI [-0.990, 0.147]).

CONCLUSIONS

Evaluating HRV and MAP can help us to understand cognitive load and its implications on trainee and physician clinical reasoning performance, with the intent to utilize this information to improve patient care.

The effect of geographic origin and destination on congenital heart disease outcomes: a retrospective cohort study

BACKGROUND

Congenital heart disease (CHD) is a common and significant birth defect, frequently requiring surgical intervention. For beneficiaries of the Department of Defense, a new diagnosis of CHD may occur while living at rural duty stations. Choice of tertiary care center becomes a function of geography, referring provider recommendations, and patient preference.

METHODS

Using billing data from the Military Health System over a 5-year period, outcomes for beneficiaries age < 10 years undergoing CHD surgery were compared by patient origin (rural versus urban residence) and the distance to treatment (patient's home and the treating tertiary care center). These beneficiaries include children of active duty, activated reserves, and federally activated National Guard service members. Analysis of the outcomes were adjusted for procedure complexity risk. Treatment centers were further stratified by annual case volume and whether they publicly reported results in the society of thoracic surgery (STS) outcomes database.

RESULTS

While increasing distance was associated with the cost of admission, there was no associated risk of inpatient mortality, one year mortality, or increased length of stay. Likewise, rural origination was not significantly associated with target outcomes. Patients traveled farther for STS-reporting centers (STS-pr), particularly high-volume centers. Such high-volume centers (> 50 high complexity cases annually) demonstrated decreased one year mortality, but increased cost and length of stay.

CONCLUSIONS

Together, these findings contribute to the national conversation of rural community medicine versus regionalized subspecialty care; separation of patients between rural areas and more urban locations for initial CHD surgical care does not increase their mortality risk. In fact, traveling to high volume centers may have an associated mortality benefit.

Atrial Rhabdomyoma Resection With Extracellular Matrix Reconstruction of the Right Atrial Free Wall in an Infant

A neonate was diagnosed with a mediastinal mass after presenting with bradycardia. At surgery, she was found to have a 4-cm mass replacing most of the right atrial free wall. After tumor resection, the right atrium was reconstructed with an extracellular matrix biomaterial that supports native tissue regeneration. Her pathology revealed rhabdomyoma, which is rare in patients without tuberous sclerosis. The procedure was well tolerated but was complicated by narrowing of the superior vena cava that required dilation postoperatively.