Modeling renal autoregulation in a hemodynamic, first-trimester gestational model.

The maternal cardiovascular system, led by renal volume regulatory responses, changes during pregnancy to ensure an adequate circulation for fetal development and growth. Circulatory maladjustment predisposes to hypertensive complications during pregnancy. Mathematical models can be used to gain insight in the gestational cardiovascular physiology. In this study, we developed an accurate, robust, and transparent model for renal autoregulation implemented in an existing circulatory gestational model. This renal autoregulation model aims to maintain steady glomerular pressure by the myogenic response, and glomerular filtration rate by tubuloglomerular feedback, both by inducing a change in the radius, and thus resistance, of the afferent arteriole. The modeled response of renal blood flow and the afferent arteriole following blood pressure increase were compared to published observations in rats. With solely the myogenic response, our model had a maximum deviation of 7% in change in renal blood flow and 7% in renal vascular resistance. When both the myogenic response and tubuloglomerular feedback were concurrently activated, the maximum deviation was 7% in change in renal blood flow and 5% in renal vascular resistance. These results show that our model is able to represent renal autoregulatory behavior comparable to empirical data. Further studies should focus on extending the model with other regulatory mechanisms to understand the hemodynamic changes in healthy and complicated pregnancy.

Irreversible Respiratory Failure in a Full-Term Infant with Features of Pulmonary Interstitial Glycogenosis as Well as Bronchopulmonary Dysplasia.

Pulmonary interstitial glycogenosis (PIG) is a rare interstitial lung disease in the newborns. We report on the clinical presentation and pathological findings of a full-term male infant with pulmonary hypertension requiring extracorporeal membrane oxygenation (ECMO). An open lung biopsy demonstrated interstitial changes resembling pulmonary interstitial glycogenosis as well as bronchopulmonary dysplasia (BPD), without convincing evidence of maturational arrest, infection, alveolar proteinosis, or alveolar capillary dysplasia. The boy was treated with glucocorticoids and, after a few days, was weaned from ECMO. A few hours later, the patient died due to acute severe pulmonary hypertension with acute right ventricular failure. The etiology and underlying pathogenic mechanisms of PIG are unknown. The clinical outcomes are quite varied. Deaths have been reported when PIG exists with abnormal lung development and pulmonary vascular growth and congenital heart disease. No mortality has been reported in PIG together with BPD in full-term infants. In this article, we reported on a full-term infant with interstitial changes resembling PIG and BPD who expired despite no convincing evidence of an anatomical maturational arrest or congenital heart disease.

Effectiveness of high fidelity video-assisted real-time simulation: a comparison of three training methods for acute pediatric emergencies.

Background. Video-assisted real-time simulation (VARS) offers the possibility of developing competence in acute medicine in a realistic and safe environment. We investigated the effectiveness of the VARS model and compared it with educational methods like Problem-Based Learning (PBL) and Pediatric Advanced Life Support (PALS). Methods. 45 fourth-year medical students were randomized for three educational methods. Level of knowledge and self-efficacy were measured before and after intervention. Clinical performance was measured by a blinded observer using a video checklist of prescripted scenarios on a high-fidelity simulator. Results. Knowledge test and self-efficacy scores improved significantly (P < 0.001) without differences between educational groups. The VARS group showed significantly (P < 0.05) higher scores on both postintervention scenarios concerning structure and time. Conclusion. VARS training is an effective educational method teaching pediatric acute care skills in the undergraduate curriculum. When compared to PBL and PALS training, VARS training appears to be superior in enhancing short-term clinical performance.