Abstract: The benign characteristics formerly attributed to Plasmodium vivax infections have recently changed owing to the increasing number of reports of severe vivax malaria resulting in a broad spectrum of clinical complications, probably including undernutrition. Causal inference is a complex process, and arriving at a tentative inference of the causal or non-causal nature of an association is a subjective process limited by the existing evidence. Applying classical epidemiology principles, such as the Bradford Hill criteria, may help foster an understanding of causality and lead to appropriate interventions being proposed that may improve quality of life and decrease morbidity in neglected populations. Here, we examined these criteria in the context of the available data suggesting that vivax malaria may substantially contribute to childhood malnutrition. We found the data supported a role for P. vivax in the etiology of undernutrition in endemic areas. Thus, the application of modern causal inference tools, in future studies, may be useful in determining causation.

Este estudo objetivou realizar revisão da literatura para verificar prevalência, fatores de risco e condições clínicas associadas à hipofosfatemia em crianças gravemente doentes. Para a pesquisa foram utilizadas as bases de dados Medline, Embase, Cochrane Library, Lilacs abrangendo estudos clínicos publicados de janeiro de 1990 a janeiro de 2004. Os termos utilizados para pesquisa foram: critically ill, pediatric intensive care, trauma, sepsis, infectious diseases, malnutrition, inflammatory response, surgery, starvation, respiratory failure, diuretic, steroid, antiacid therapy, mechanical ventilation. Foram excluídos estudos referentes a distúrbios endócrinos, síndromes genéticas, raquitismo, nefropatias, anorexia nervosa, alcoolismo e prematuridade. Dos 27 artigos inicialmente identificados, 8 referiam-se à faixa etária pediátrica, sendo a maioria deles relatos de casos isolados. Nos estudos clínicos selecionados, a prevalência de hipofosfatemia foi superior a 50%. Os principais fatores associados à hipofosfatemia foram realimentação, desnutrição, sepse, trauma, uso de diuréticos e corticoesteróides. Considerando-se a elevada prevalência, as repercussões clínicas e os múltiplos fatores de risco para hipofosfatemia em crianças internadas em unidade de cuidados intensivos, a identificação precoce de pacientes suscetíveis a esse distúrbio é essencial para o tratamento oportuno e prevenção de complicações.

The purpose of this paper is to review clinical studies on hypophosphatemia in pediatric intensive care unit patients with a view to verifying prevalence and risk factors associated with this disorder. We searched the computerized bibliographic databases Medline, Embase, Cochrane Library, and LILACS to identify eligible studies. Search terms included critically ill, pediatric intensive care, trauma, sepsis, infectious diseases, malnutrition, inflammatory response, surgery, starvation, respiratory failure, diuretic, steroid, antiacid therapy, mechanical ventilation. The search period covered those clinical trials published from January 1990 to January 2004. Studies concerning endocrinological disorders, genetic syndromes, rickets, renal diseases, anorexia nervosa, alcohol abuse, and prematurity were not included in this review. Out of 27 studies retrieved, only 8 involved pediatric patients, and most of these were case reports. One clinical trial and one retrospective study were identified. The prevalence of hypophosphatemia exceeded 50%. The commonly associated factors in most patients with hypophosphatemia were refeeding syndrome, malnutrition, sepsis, trauma, and diuretic and steroid therapy. Given the high prevalence, clinical manifestations, and multiple risk factors, the early identification of this disorder in critically ill children is crucial for adequate replacement therapy and also to avoid complications.