Optimizing Medical Student Clerkship Schedules Using a Novel Application of the Hungarian Algorithm.

PROBLEM: Medical students often have preferences regarding the order of their clinical rotations, but assigning rotations fairly and efficiently can be challenging. To achieve a solution that optimizes assignments (i.e., maximizes student satisfaction), the authors present a novel application of the Hungarian algorithm, designed at the University of Texas Southwestern Medical Center (UTSW), to assign student schedules. APPROACH: Possible schedules were divided into distinct pathway options with k total number of seats. Each of n students submitted a ranked list of their top 5 pathway choices. An n × k matrix was formed, where the location (i, j) represented the cost associated with student i being placed in seat j. Progressively higher costs were assigned to students receiving less desired pathways. The Hungarian algorithm was then used to find the assignments that minimize total cost. The authors compared the performance of the Hungarian algorithm against 2 alternative algorithms (i.e., the rank and lottery algorithms). To evaluate the 3 algorithms, 4 simulations were conducted with different popularity weights for different pathways and were run across 1,000 trials. The algorithms were also compared using 3 years of UTSW student preference data for the classes of 2019, 2020, and 2021. OUTCOMES: In all 4 computer simulations, the Hungarian algorithm resulted in more students receiving 1 of their top 3 choices and fewer students receiving none of their preferences. Similarly, for UTSW student preference data, the Hungarian algorithm resulted in more students receiving 1 of their top 3 preferences and fewer students receiving none of their ranked preferences. NEXT STEPS: This approach may be broadly applied to scheduling challenges in undergraduate and graduate medical education. Furthermore, by manipulating cost values, additional constraints can be enforced (e.g., requiring certain seats to be filled, attempting to avoid schedules that begin with a student's desired specialty).

Circulating blasts and associated hematologic disorders in neonates with Down syndrome.

We analyzed complete blood count (CBC) data obtained from neonates with Down syndrome (DS) in a primarily Hispanic population over a 10-year period to determine the incidence of hematologic abnormalities and the relationship of abnormalities to the presence of circulating blasts (CB). Hematologic values obtained during the first 10 days were analyzed. Definitions were: CB, ≥ 1% blasts manually counted on peripheral smear; elevated white blood cell count (WBC), >30,000 cells/mm(3); thrombocytopenia, platelet count < 150,000/mm(3); polycythemia, hematocrit >65%. Two hundred thirty-two neonates (88% Hispanic) with DS had 692 CBCs available for analysis. The presence of CB (11.6%) and the incidence of thrombocytopenia (60.2%) were significantly higher in DS neonates than in the reference group. Elevated WBC (33.3%) and thrombocytopenia (84.6%) were more common in DS neonates with CB versus those with no CB. No relationship between thrombocytopenia and polycythemia was observed. Unlike previous reports, we did not observe a male predominance in those DS neonates with CB. Thrombocytopenia occurred frequently in DS neonates and was significantly more likely in those with CB than in those with no CB. CBC screening should be performed routinely in DS neonates.

Pulse oximetry screening at 4 hours of age to detect critical congenital heart defects.

OBJECTIVE: The purpose of this prospective study was to assess the feasibility and reliability of pulse oximetry screening to detect critical congenital heart defects in a newborn nursery. METHODS: The study was performed in a large urban hospital with an exclusively inborn population. Stable neonates who had a gestational age of >or=35 weeks and birth weight of >or=2100 g and in whom a critical congenital heart defect was not suspected were admitted to the newborn nursery. When the 4-hour pulse oximetry reading was <96%, pulse oximetry was repeated at discharge, and when the pulse oximetry reading remained at persistently <96%, echocardiography was performed. RESULTS: Of 15299 admissions to newborn nursery during the 12-month study period, 15233 (99.6%) neonates were screened with 4-hour pulse oximetry. Pulse oximetry readings were >or=96% for 14374 (94.4%) neonates; 77 were subsequently evaluated before discharge for cardiac defects on the basis of clinical examination. Seventy-six were normal, and 1 had tetralogy of Fallot with discontinuous pulmonary arteries. Pulse oximetry readings at 4 hours were <96% in 859 (5.6%); 768 were rescreened at discharge, and 767 neonates had a pulse oximetry reading at >or=96%. One neonate had persistently low pulse oximetry at discharge; echocardiography was normal. Although 3 neonates with a critical congenital heart defect had a 4-hour pulse oximetry reading of <96%, all developed signs and/or symptoms of a cardiac defect and received a diagnosis on the basis of clinical findings, not screening results. CONCLUSIONS: All neonates with a critical congenital heart defect were detected clinically, and no cases of critical congenital heart defect were detected by pulse oximetry screening. These results indicate that pulse oximetry screening does not improve detection of critical congenital heart defects above and beyond clinical observation and assessment. Our findings do not support a recommendation for routine pulse oximetry screening in seemingly healthy neonates.

Newborn hearing screening and detection of congenital cytomegalovirus infection.

OBJECTIVES: The objectives were to determine the frequency of congenital cytomegalovirus infection among newborns who did not pass hearing screening tests or had confirmed hearing loss and to determine how often abnormal hearing screening results were the only manifestation of congenital cytomegalovirus infection. METHODS: Retrospective chart review was performed for newborns who had abnormal hearing screening results and positive urine cytomegalovirus culture results at Parkland Memorial Hospital between September 1, 1999, and August 31, 2004. RESULTS: During the 5-year study period, 572 of 79047 newborns (7 of 1000 live births) did not pass hearing screening tests. Cytomegalovirus infection was identified in 24 (5%) of 483 tested infants and 16 (6%) of the 256 infants with subsequently confirmed hearing impairment. Of those 16 infants, 12 (75%) were identified as having congenital cytomegalovirus infection only because of failure to pass newborn hearing screening tests. CONCLUSIONS: Congenital cytomegalovirus infection was present for 6% of newborns with confirmed hearing impairment, and the majority of those infants were identified on the basis of abnormal newborn hearing screening results.

Evaluation of a transcutaneous jaundice meter following hospital discharge in term and near-term neonates.

OBJECTIVES: To evaluate performance of the Minolta JM-103 Jaundice Meter (JM) as a predictor of total serum bilirubin (TSB) in outpatient neonates during the first week postnatal, and to estimate the number of TSB determinations that might be avoided in clinical use. STUDY DESIGN: In neonates evaluated posthospital discharge, JM and TSB results were compared using linear regression and a Bland-Altman plot, and predictive indices were calculated for various JM cutoff values. Utilizing the 2004 American Academy of Pediatrics (AAP) guidelines, the ability of JM to predict risk zone status was determined. RESULTS: Overall correlation between JM and TSB was 0.77 (p<0.001; n=121). When TSB was >17 mg/dl, a cutoff value for JM of 13 mg/dl had a sensitivity of 1.0, and 50% of TSB determinations would be avoided. CONCLUSIONS: JM may facilitate outpatient management of hyperbilirubinemia by reducing the number of TSB determinations required; however, it does not provide a reliable substitute for laboratory measurement of TSB.

Are complete blood cell counts useful in the evaluation of asymptomatic neonates exposed to suspected chorioamnionitis?

OBJECTIVE: Chorioamnionitis complicates 1% to 10% of pregnancies and increases the risk of neonatal infection. Women with chorioamnionitis receive intrapartum antibiotics, often resulting in inconclusive neonatal blood cultures. Peripheral neutrophil values are used frequently to assist in the diagnosis of neonatal infection and to determine duration of antibiotics; we sought to determine the utility of this approach. METHODS: A prospective observational study was performed in 856 near-term/term neonates who were exposed to suspected chorioamnionitis. Each received antibiotics for 48 hours unless clinical infection or positive blood cultures occurred. Peripheral neutrophils were measured serially and analyzed using the reference ranges of Manroe et al; an additional analysis of only the initial neutrophil values used the normal ranges of Schelonka et al. Results of neutrophil analyses were not used to determine duration of therapy. Fifty percent of asymptomatic neonates were seen postdischarge to ascertain recurrent infection. Local patient charges were examined. RESULTS: Ninety-six percent of neonates were asymptomatic and had negative cultures, and antibiotics were discontinued at 48 hours. A total of 2427 neutrophil counts were analyzed. Although abnormal neutrophil values were more frequent in infected or symptomatic neonates, 99% of asymptomatic neonates had > or = 1 abnormal value. The specificity and negative predictive values for abnormal neutrophil values ranged between 0.12 and 0.95 and 0.91 and 0.97, respectively; sensitivity was 0.27 to 0.76. Significant differences in interpretation of the initial neutrophil values were noted, depending on the normal values used. Follow-up was performed for 373 asymptomatic neonates until 3 weeks' postnatal age. Eight required rehospitalization; none had evidence of bacterial infection. If neutrophil values had been used to determine duration of antibiotics, then local costs would have increased by 76,000 dollars to 425,000 dollars per year. CONCLUSIONS: Single or serial neutrophil values do not assist in the diagnosis of early-onset infection or determination of duration of antibiotic therapy in asymptomatic, culture-negative neonates who are > or = 35 weeks' gestation and are delivered of women with suspected chorioamnionitis.

Pneumonia in term neonates: laboratory studies and duration of antibiotic therapy.

OBJECTIVES: To compare 2 days of antibiotic therapy (AT) to 4 days of AT in neonates with pneumonia and to assess the usefulness of neutrophil values (NV), C-reactive protein (CRP), and procalcitonin (PCT) in this population. DESIGN: The study population consisted of consecutive, eligible term neonates begun on AT for suspected pneumonia. Of 51 neonates, 26 qualified for randomization (14, 2-day group; 12, 4-day group). NV were obtained with the initial evaluation and 12 and 24 hours later. CRP and PCT were obtained 12 and 48 hours after the initial evaluation. RESULTS: None of the 12 neonates in the 4-day group developed recurrent respiratory symptoms. Three of the 14 neonates randomized to the 2-day group had recurrence of symptoms, resulting in study termination. NV, CRP, and PCT were similar in the 2- and 4-day groups. In the three neonates who developed respiratory symptoms, all absolute total neutrophil values and five out of nine absolute total immature neutrophil values were abnormal. However, all immature:total neutrophil values were normal, and CRP was strikingly elevated in only one neonate; only one of six PCT values was abnormal. In a secondary analysis of all 51 study neonates, CRP and PCT did not provide additional benefit over NV in differentiating neonates with pneumonia. CONCLUSIONS: Four days of AT appears to be adequate for selected term neonates with pneumonia; however, 2 days of AT appears to be inadequate for this population. Relative to NV, CRP and PCT appear to have a limited role.

Association of hypocalcemia with a change in gentamicin administration in neonates.

Aminoglycosides are administered frequently to neonates with suspected sepsis. We report the association of hypocalcemia in term and near-term neonates receiving gentamicin therapy for >/=4 days after a change in dosing from every 12 h to every 24 h. The possible association with a higher gentamicin dose and longer dosing interval is described.