Medical Student Attitudes toward USMLE Step 1 and Health Systems Science - A Multi-Institutional Survey.

Phenomenon: Because of its importance in residency selection, the United States Medical Licensing Examination Step 1 occupies a critical position in medical education, stimulating national debate about appropriate score use, equitable selection criteria, and the goals of undergraduate medical education. Yet, student perspectives on these issues and their implications for engagement with health systems science-related curricular content are relatively underexplored. Approach: We conducted an online survey of medical students at 19 American allopathic medical schools from March-July, 2019. Survey items were designed to elicit student opinions on the Step 1 examination and the impact of the examination on their engagement with new, non-test curricular content related to health systems science. Findings: A total of 2856 students participated in the survey, representing 23.5% of those invited. While 87% of students agreed that doing well on the Step 1 exam was their top priority, 56% disagreed that studying for Step 1 had a positive impact on engagement in the medical school curriculum. Eighty-two percent of students disagreed that Step 1 scores should be the top item residency programs use to offer interviews. When asked whether Step 1 results should be reported pass/fail with no numeric score, 55% of students agreed, while 33% disagreed. The majority of medical students agreed that health systems science topics were important but disagreed that studying for Step 1 helped learn this content. Students reported being more motivated to study a topic if it was on the exam, part of a course grade, prioritized by residency program directors, or if it would make them a better physician in the future. Insights: These results confirm the primacy of the United States Medical Licensing Examination Step 1 exam in preclinical medical education and demonstrate the need to balance the objectives of medical licensure and residency selection with the goals of the broader medical profession. The survey responses suggest several potential solutions to increase student engagement in health systems science curricula which may be especially important after Step 1 examination results are reported as pass/fail.

Caffeine exposure and acute kidney injury in premature infants with necrotizing enterocolitis and spontaneous intestinal perforation.

BACKGROUND: Acute kidney injury (AKI) is common in preterm infants, but specific therapies remain scarce. Recent studies have demonstrated an association between caffeine exposure and less frequent AKI in the first 7-10 days after birth. We hypothesized that patients with necrotizing enterocolitis (NEC) and spontaneous intestinal perforation (SIP) would provide a better natural model of AKI to evaluate this association. METHODS: We reviewed all premature patients diagnosed with NEC or SIP at our institution from 2008 to 2014. AKI was defined by change in serum creatinine using the neonatal Kidney Disease: Improving Global Outcomes definition. Caffeine was prescribed for apnea of prematurity and caffeine exposure was determined by chart review. RESULTS: A total of 146 patients with NEC/SIP were reviewed. Of these, 119 (81.5%) received caffeine, and 91 (62.3%) developed AKI. AKI occurred less frequently in patients who received caffeine than in those who did not (55.5% vs. 92.6%; odds ratio (OR) 0.10; 95% confidence interval (CI) 0.02-0.44). This association persisted in multivariable models after adjustment for potential confounders (adjusted OR 0.08; 95% CI 0.01-0.42; number needed to be exposed to caffeine to prevent one case of AKI = 2.6). Although baseline serum creatinine did not differ by caffeine exposure, patients receiving caffeine had lower peak creatinine (median 1.0 mg/dl vs. 1.5 mg/dl; p = 0.008) and absolute creatinine change (median 0.42 mg/dl vs. 0.68 mg/dl; p = 0.003) than those who did not. CONCLUSIONS: Caffeine exposure in preterm infants with NEC/SIP is associated with decreased incidence and severity of AKI.

Metabolic risk factors in nondiabetic adolescents with glomerular hyperfiltration.

BACKGROUND: In adults, glomerular hyperfiltration is associated with abnormalities related to metabolic syndrome (MetS). We investigated if glomerular hyperfiltration was associated with metabolic abnormalities in US adolescents without diabetes. METHODS: We analyzed data from the National Health and Nutrition Examination Survey, a nationally representative sample of US adolescents ages 12-17 years. Estimated glomerular filtration rate (eGFR) was determined using the bedside Schwartz equation; adolescents with hyperfiltration (eGFR >120 mL/min/1.73 m 2 ) were compared to those with normal eGFR (90-120 mL/min/1.73 m 2 ). We calculated mean levels of factors related to MetS, insulin resistance and diabetes risk, adjusting for age, race/ethnicity, sex, socioeconomic status, and BMI z -score. RESULTS: Overall, 11.8% of US adolescents had hyperfiltration [95% confidence interval (CI) 10.6-13.0]. Hyperfiltration prevalence varied by race (20.2% in Hispanics versus 9.8% non-Hispanic whites and 7.4% non-Hispanic blacks; P< 0.001). Compared to those with normal eGFR, adolescents with hyperfiltration had higher adjusted mean levels of triglyceride (83 versus 77 mg/dL; P = 0.05), fasting insulin (15.1 versus 12.9; P< 0.001) and homeostatic model assessment of insulin resistance (3.52 versus 3.01; P = 0.001). These differences persisted after adjusting for BMI z- score. Adolescents with hyperfiltration had increased odds for hypertriglyceridemia [odds ratio 1.58 (95% CI 1.11-2.23)]. These relationships varied by racial/ethnic group. CONCLUSIONS: Glomerular hyperfiltration is associated with hypertriglyceridemia and increased insulin resistance independent of BMI z- score in a nationally representative sample of US adolescents. Hispanic adolescents are more likely to have hyperfiltration than other racial/ethnic groups. These findings could have significance in evaluations of renal function and MetS in adolescents to identify related risks and target interventions.

Birthweight and serum uric acid in American adolescents.

Elevated serum uric acid is associated with hypertension and chronic kidney disease. We evaluated the relationship between birthweight and uric acid in a nationally representative sample of 5390 US adolescents aged 12-15 in the National Health and Nutrition Examination Survey from 1999 to 2012. There was an inverse association between birthweight and uric acid after adjustment for sex, age, race, obesity, and dietary sodium intake. Each 1 kg increase in birthweight was associated with decreased uric acid by 0.11 mg/dL (95% CI: -0.16 to -0.06; model R2  = 0.32). This relationship was stronger in adolescents with elevated blood pressure (ß = -0.25; 95% CI: -0.44 to -0.06; R2  = 0.50) but persisted in adolescents with normal blood pressure (ß = -0.10; 95% CI: -0.15 to -0.05; R2  = 0.31). In conclusion, lower birthweight is associated with higher uric acid in US adolescents. These findings may support the hypothesis that reduced nephron number is associated with elevated uric acid.

How to use serum creatinine, cystatin C and GFR.

Glomerular filtration rate (GFR) is the best overall measure of kidney function. The GFR is relatively low at birth but increases through infancy and early childhood to reach adult levels of approximately 120 mL/min/1.73 m2 by age 2. While GFR can be measured most accurately by the urinary clearance of an exogenous ideal filtration marker such as inulin, it is more clinically useful to estimate GFR using a single serum measurement of an endogenous biomarker such as creatinine or cystatin C. When in steady state, there is an inverse relationship between creatinine/cystatin C and GFR, allowing GFR to be estimated from either using simple equations. Because of the non-linear relationship between creatinine/cystatin C and GFR, relatively small initial increases in these markers represent significant decreases in GFR. While cystatin C is produced by all nucleated cells, creatinine is a waste product of muscle metabolism and is therefore influenced by diet and muscle mass/body habitus. Decreased GFR is used to diagnose and stage chronic kidney disease (CKD) using the Kidney Disease: Improving Global Outcomes system. A diagnosis of CKD requires GFR <60 mL/min/1.73 m2 for more than 3 months; higher GFR also represents CKD if evidence of kidney damage (such as albuminuria or abnormal imaging) is present. Changes in serum creatinine and urine output are used to diagnose acute kidney injury. It is possible to calculate a kinetic GFR when the creatinine is changing rapidly, though more complex calculations are required.

Caffeine Exposure and Risk of Acute Kidney Injury in a Retrospective Cohort of Very Low Birth Weight Neonates.

OBJECTIVE: To evaluate the association between caffeine exposure and acute kidney injury (AKI) in very low birth weight (VLBW; ≤1500 g) neonates. STUDY DESIGN: We retrospectively reviewed a cohort of 140 VLBW neonates consecutively admitted to the University of Virginia's neonatal intensive care unit from March 2011 to June 2012, excluding only those admitted >2 days of age or who died at <2 days after birth. We separately analyzed a subgroup of 44 neonates who received prolonged invasive respiratory support (mechanical ventilation for first 7 days after birth). The exposure of interest was caffeine exposure in the first week after birth. The primary outcome was AKI within the first 10 days after birth according to the Kidney Disease: Improving Global Outcomes system, modified to include only serum creatinine. RESULTS: Caffeine exposure occurred in 72.1% of all patients and 54.5% of those who received prolonged invasive respiratory support. AKI occurred less frequently in neonates who received caffeine (all patients: 17.8% vs 43.6%; P = .002; prolonged invasive respiratory support: 29.2% vs 75.0%; P = .002). Caffeine exposure was associated with decreased odds for AKI in logistic regression models adjusted for sex, birth weight, gestational age, small for gestational age status, illness severity on admission, and receipt of indomethacin, invasive ventilation, dopamine, aminoglycosides, and vancomycin (all patients: OR 0.22; 95% CI 0.07-0.75, P = .02; prolonged invasive respiratory support subgroup: OR 0.06; 95% CI 0.01-0.57, P = .02). CONCLUSIONS: In a cohort of VLBW neonates, those exposed to caffeine were less likely to experience AKI.

Prevalence of chronic kidney disease risk factors among low birth weight adolescents.

BACKGROUND: By adulthood, low birth weight infants have an increased risk for chronic kidney disease (CKD). The extent to which objective CKD risk factors are present at earlier ages is unclear. METHODS: We analyzed 5352 participants aged 12-15 years in the National Health and Nutrition Examination Survey, 1999-2012. Participants were classified as low birth weight (LBW; < 2500 g), very low birth weight (VLBW; < 1500 g), or normal (2500-4000 g) by parental/proxy recall. Albuminuria (albumin/creatinine 30 - <300 mg/g), decreased estimated glomerular filtration rate (eGFR; < 90 ml/min/1.73 m(2); Counahan-Barratt), and elevated systolic blood pressure (BP; ≥ 95th percentile for age, height, and sex) were considered CKD risk factors. RESULTS: While albuminuria did not vary by birth weight, elevated blood pressure (BP) and decreased eGFR occurred more frequently in LBW/VLBW adolescents (elevated BP: LBW 6.0 %, VLBW 11.2 %, normal 2.4 %; decreased eGFR: LBW 23.2 %, VLBW 32.5 %, normal 16.1 %). After multivariable adjustment, LBW/VLBW adolescents had greater odds for both elevated BP (LBW: OR 2.90, 95 % CI 1.48-5.71; VLBW: 5.23; 1.11-24.74) and decreased eGFR (LBW: 1.49, 95 % CI 1.06-2.10; VLBW 2.49, 95 % CI 1.20-5.18). CONCLUSIONS: In the U.S. population, both decreased eGFR and elevated systolic BP occur frequently among adolescents with history of LBW/VLBW.

Reusable, robust, and accurate laser-generated photonic nanosensor.

Developing noninvasive and accurate diagnostics that are easily manufactured, robust, and reusable will provide monitoring of high-risk individuals in any clinical or point-of-care environment. We have developed a clinically relevant optical glucose nanosensor that can be reused at least 400 times without a compromise in accuracy. The use of a single 6 ns laser (λ = 532 nm, 200 mJ) pulse rapidly produced off-axis Bragg diffraction gratings consisting of ordered silver nanoparticles embedded within a phenylboronic acid-functionalized hydrogel. This sensor exhibited reversible large wavelength shifts and diffracted the spectrum of narrow-band light over the wavelength range λpeak ≈ 510-1100 nm. The experimental sensitivity of the sensor permits diagnosis of glucosuria in the urine samples of diabetic patients with an improved performance compared to commercial high-throughput urinalysis devices. The sensor response was achieved within 5 min, reset to baseline in ∼10 s. It is anticipated that this sensing platform will have implications for the development of reusable, equipment-free colorimetric point-of-care diagnostic devices for diabetes screening.

Nephron number and its determinants in early life: a primer.

Although there is wide variation, humans possess on average 900,000 nephrons per kidney. So far as is known, nephrons cannot regenerate; therefore, an individual's nephron endowment has profound implications in determining his or her long-term risk of developing chronic kidney disease. Most of the variability in human nephron number is determined early in life. Nephrogenesis is a complex and carefully orchestrated process that occurs during a narrow time window until 36 weeks gestation in humans, and disruption of any part of this sequence may lead to reduced nephron number. In utero, genetic abnormalities, toxic insults, and nutritional deficiencies can each alter final nephron number. Infants born prematurely must continue nephrogenesis in an ex utero environment where there may be multiple threats to successful nephrogenesis. Once the nephron endowment is determined, postnatal factors (such as acute kidney injury or chronic illnesses) can only decrease nephron number. Current techniques for estimating nephron number require an invasive procedure or complete destruction of the tissue, making noninvasive means for counting nephron surgently needed. A better understanding of nephron number and its determinants, particularly during growth and maturation, could allow the development of therapies to support, prolong, or resume nephrogenesis.

Pre-operative renal volume predicts peak creatinine after congenital heart surgery in neonates.

OBJECTIVE: Acute kidney injury is common in neonates following surgery for congenital heart disease. We conducted a retrospective analysis to determine whether neonates with smaller pre-operative renal volume were more likely to develop post-operative acute kidney injury. DESIGN/SETTING: We conducted a retrospective review of 72 neonates who underwent congenital heart surgery for any lesion other than patent ductus arteriosus at our institution from January 2007 to December 2011. Renal volume was calculated by ultrasound using the prolate ellipsoid formula. The presence and severity of post-operative acute kidney injury was determined both by measuring the peak serum creatinine in the first 7 days post-operatively and by using the Acute Kidney Injury Network scoring system. RESULTS: Using a linear change point model, a threshold renal volume of 17 cm³ was identified. Below this threshold, there was an inverse linear relationship between renal volume and peak post-operative creatinine for all patients (p = 0.036) and the subgroup with a single morphologic right ventricle (p = 0.046). There was a non-significant trend towards more acute kidney injury using Acute Kidney Injury Network criteria in all neonates with renal volume ≤17 cm³ (p = 0.11) and in the subgroup with a single morphologic right ventricle (p = 0.17). CONCLUSIONS: Pre-operative renal volume ≤17 cm³ is associated with a higher peak post-operative creatinine and potentially greater risk for post-operative acute kidney injury for neonates undergoing congenital heart surgery. Neonates with a single right ventricle may be at higher risk.

Paediatric acid-base disorders: A case-based review of procedures and pitfalls.

Acid-base disorders occur frequently in paediatric patients. Despite the perception that their analysis is complex and difficult, a straightforward set of rules is sufficient to interpret even the most complex disorders - provided certain pitfalls are avoided. Using a case-based approach, the present article reviews the fundamental concepts of acid-base analysis and highlights common mistakes and oversights. Specific topics include the proper identification of the primary disorder; distinguishing compensatory changes from additional primary disorders; use of the albumin-corrected anion gap to generate a differential diagnosis for patients with metabolic acidosis; screening for mixed disorders with the delta-delta formula; recognizing the limits of compensation; use of the anion gap to identify 'hidden' acidosis; and the importance of using information from the history and physical examination to identify the specific cause of a patient's acid-base disturbance.

Les troubles de l'équilibre acido-basique sont fréquents chez les patients d'âge pédiatrique. Même si on les croit difficiles et complexes à analyser, des règles simples suffsent pour interpréter même les troubles les plus complexes, pourvu qu'on évite certains écueils.Au moyen d'une approche fondée sur des cas, le présent article contient les concepts fondamentaux de l'analyse acido-basique et fait ressortir des erreurs et des omissions courantes. Les thèmes abordés incluent la bonne détermination du trouble primaire, la distinction entre les changements compensatoires et d'autres troubles primaires, l'utilisation du trou anionique corrigé par l'albumine pour produire un diagnostic différentiel chez les patients ayant une acidose métabolique, le dépistage de troubles mixtes au moyen de la formule delta-delta, la détermination des limites de compensation, l'utilisation du trou anionique pour dépister une acidose « cachée ¼ et l'importance d'utiliser l'information tirée de l'anamnèse et de l'examen physique pour déterminer la cause précise de la perturbation acido-basique du patient.

An Update on Medical School Accreditation in the United States: Implications for the Single Graduate Medical Education (GME) Era.

In the United States, medical schools are accredited by either the Liaison on Committee Medical Education (LCME) or the Commission on Osteopathic College Accreditation (COCA), which assesses the quality and standards of Doctor of Medicine (MD)-granting and Doctor of Osteopathic Medicine (DO)-granting institutions, respectively. Thereafter, new MD and DO physicians complete graduate medical education (GME) training. Historically, the two physician licensure pathways have been predominantly separate, but in 2020, the Accreditation Council for Graduate Medical Education and American Osteopathic Association finalized a single accreditation GME system. Now, other elements of MD and DO physician training that have traditionally remained separate, such as undergraduate medical education (UME), are increasingly being scrutinized. Since 2010, when the accreditation of UME was last qualitatively criticized, the standards and competencies set forth by LCME and COCA have converged. COCA, in particular, has updated its requirements to emphasize scholarly activity, improve inpatient clinical rotation requirements, engage medical students, and enhance clinical faculty qualifications. Such convergence brings to question the continuing need for two independent accreditation pathways and barriers that may prevent a single accreditation. We argue that although MD and DO physicians are unique, the natural confluence of UME accreditation represents an opportunity to simplify and improve physician training in the United States. Our analysis suggests the major barriers to implementing a single accreditation system surround the requirement of Osteopathic Manipulative Medicine (OMM)-focused faculty by COCA and the two separate licensing exams (USMLE (United States Medical Licensing Examination) and COMLEX (Comprehensive Osteopathic Medical Licensing Examination)). However, with a continuing decline in osteopathic physicians practicing OMM and growing debate over a new single licensing exam, a single accreditation UME system may be practically achieved.

A clinical approach to paediatric acid-base disorders.

Acid-base disorders are common in pediatric patients. We present a simple methodology for assessing both simple and complex acid-base disorders that is applicable to patients of all ages, and focus specifically on the usefulness of this approach in the pediatric patient. The application of four simple rules in sequence will define even the most complicated acid-base disturbance. However, because acid-base disorders are manifestations of systemic disorders, the primary value of characterizing them is that each generates a unique differential diagnosis. For each of the cardinal acid base disorders, the common and clinically-relevant causes in pediatric patients are explored. Additional diagnostic tools (including the serum anion gap, the delta-delta, the alveolar-arterial gradient, urine anion gap, and urine chloride), certain easily-recalled mnemonics, and empiric rules of thumb are also useful in specific situations. The treatment of acid-base disturbances is also considered, though treatment is generally best directed at the underlying disorder.

Application Fever: Reviewing the Causes, Costs, and Cures for Residency Application Inflation.

Over the past decade, the number of residency applications submitted per applicant has nearly doubled. This epidemic of "Application Fever" is expensive for applicants, burdensome for programs, and ultimately does not improve overall Match outcomes. In this review, we discuss the phenomenon of Application Fever, with a focus on contributing factors and costs of this behavior. Application Fever has its origins in the early 1990s. At that time, the number of residency applicants began to outpace the number of available positions. Because an applicant who applies to more residency programs has a greater probability of securing a residency position than an otherwise equivalent applicant who applies to fewer, "overapplication" became a dominant strategy and residency applicants began to apply to more residency programs each year. This trend was enhanced and enabled by the introduction of the Electronic Residency Application Service (ERAS). Although Application Fever is a rational decision for applicants, it imposes a substantial evaluative burden on program directors and necessitates the use of convenience screening metrics. We then briefly review potential solutions, including informational strategies, application limits, and marketplace incentives to reduce application numbers. Although a fixed cap on applications would reduce application numbers and facilitate a holistic selection process, greater transparency from residency programs regarding their selection criteria would be required to help applicants choose where to apply. To improve the residency application process for programs and applicants alike, we call upon the medical community to further study Application Fever and carefully consider solutions, including fixed application caps.