Tailoring management of severe and complicated malnutrition: more research is required first

Cardiac Dysfunction in a Porcine Model of Pediatric Malnutrition

BACKGROUND

Half a million children die annually of severe acute malnutrition and cardiac dysfunction may contribute to the mortality. However, cardiac function remains poorly examined in cases of severe acute malnutrition.

OBJECTIVE

To determine malnutrition-induced echocardiographic disturbances and longitudinal changes in plasma pro-atrial natriuretic peptide and cardiac troponin-T in a pediatric porcine model.

METHODS AND RESULTS

Five-week old piglets (Duroc-x-Danish Landrace-x-Yorkshire) were fed a nutritionally inadequate maize-flour diet to induce malnutrition (MAIZE, n = 12) or a reference diet (AGE-REF, n = 12) for 7 weeks. Outcomes were compared to a weight-matched reference group (WEIGHT-REF, n = 8). Pro-atrial natriuretic peptide and cardiac troponin-T were measured weekly. Plasma pro-atrial natriuretic peptide decreased in both MAIZE and AGE-REF during the first 3 weeks but increased markedly in MAIZE relative to AGE-REF during week 5-7 (p ≤ 0.001). There was overall no difference in plasma cardiac troponin-T between groups. However, further analysis revealed that release of cardiac troponin-T in plasma was more frequent in AGE-REF compared with MAIZE (OR: 4.8; 95%CI: 1.2-19.7; p = 0.03). However, when release occurred, cardiac troponin-T concentration was 6.9-fold higher (95%CI: 3.0-15.9; p < 0.001) in MAIZE compared to AGE-REF. At week 7, the mean body weight in MAIZE was lower than AGE-REF (8.3 vs 32.4 kg, p < 0.001), whereas heart-weight relative to body-weight was similar across the three groups. The myocardial performance index was 86% higher in MAIZE vs AGE-REF (p < 0.001) and 27% higher in MAIZE vs WEIGHT-REF (p = 0.025).

CONCLUSIONS

Malnutrition associates with cardiac dysfunction in a pediatric porcine model by increased myocardial performance index and pro-atrial natriuretic peptide and it associates with cardiac injury by elevated cardiac troponin-T. Clinical studies are needed to see if the same applies for children suffering from malnutrition.

Fluid management of shock in severe malnutrition: what is the evidence for current guidelines and what lessons have been learned from clinical studies and trials in other pediatric populations?

Management of shock in children with severe malnutrition remains controversial. To date, the evidence supporting either benefit or harm of fluid resuscitation or rehydration is weak. This issue, however, is not unique to children with severe malnutrition; pediatric guidelines worldwide have a weak level of evidence and remain unsupported by appropriate clinical studies. In this review we give an overview of the current recommendations in other pediatric populations and appraise the strength of evidence supporting these. We summarize results from the only controlled trial ever undertaken, FEAST (Fluid Expansion As Supportive Therapy), which was conducted in resource-poor hospitals involving 3,141 African children with severe febrile illnesses and shock, including large subgroups with sepsis and malaria but excluding children with severe malnutrition. This high-quality trial provided robust evidence that fluid resuscitation increased the risk of death, leading to an excess mortality of 3 in every 100 children receiving fluid boluses, compared with controls receiving no boluses. These findings may have particular relevance to management of septic shock in children with severe malnutrition. However, they cannot be extrapolated to children with gastroenteritis, since this condition was not included in the trial. Current observational studies under way in East Africa may provide insights into myocardial and hemodynamic function in severe malnutrition, including responses to fluid challenge in those complicated by gastroenteritis. Such studies are an essential step for setting the research agenda regarding fluid management of shock in severe malnutrition.