Blood zinc, iron, and copper levels in critically ill neonates

Micronutrient status during paediatric critical illness: A scoping review

Background

No evidence based recommendations for micronutrient requirements during paediatric critical illness are available, other than those arising from recommended nutrient intakes (RNI) for healthy children and expert opinion.

Objectives

The objective of this review is to examine the available evidence from micronutrient status in critically ill children considering studies which describe 1) micronutrient levels, 2) associations between micronutrient levels and clinical outcome, and 3) impact on clinical outcome with micronutrient supplementation during PICU admission.

Design

Scoping review.

Eligibility criteria

Any study which used a qualitative and quantitative design considering causes and consequences of micronutrient levels or micronutrient supplementation during paediatric critical illness.

Sources of evidence

NICE Healthcare Databases Advanced Search website (https://hdas.nice.org.uk/) was used as a tool for multiple searches, with a content analysis and charting of data extracted.

Results

711 records were identified, 35 were included in the review. Studies evaluated serum micronutrient status was determined on admission day in majority of patients. A content analysis identified (n = 49) initial codes, (n = 14) sub-categories and (n = 5) overarching themes during critical illness, which were identified as: i) low levels of micronutrients, ii) causes of aberrant micronutrient levels, iii) associations between micronutrients levels and outcome, iv) supplementation of micronutrients.

Conclusion

During critical illness, micronutrients should be provided in sufficient amounts to meet reference nutrient intakes for age. Although, there is insufficient data to recommend routine supplementations of micronutrients at higher doses during critical illness, the ‘absence of evidence should not imply evidence of absence’, and well designed prospective studies are urgently needed to elucidate paediatric micronutrient requirements during critical illness. The absence of reliable biomarkers make it challenging to determine whether low serum levels are reflective of a true deficiency or as a result redistribution, particularly during the acute phase of critical illness. As more children continue to survive a PICU admission, particularly those with complex diseases micronutrient supplementation research should also be inclusive of the recovery phase following critical illness.

Changes of serum trace elements in early stage trauma and its correlation with injury severity score

BACKGROUND

Severe trauma can cause secondary multiple organ dysfunction syndrome and death. The absolute and relative concentrations of trace elements in both critical care and conventional treatment, which can lead to acute trace element deficiency, constitute an important mechanism of multiple organ dysfunction syndrome (MODS)/multiple organ failure (MOF).

METHODS

We investigated the changes in serum Cu, Zn, and Fe in early stage trauma of patients with the high injury severity score (ISS) and correlated the change in trace elements with ISS. Blood samples were collected within an hour of admittance and the patients were scored according to ISS. We collected clinical data records and ISS score values, and determined serum Fe, Zn, and Cu by inductively coupled plasma mass spectrometry.

RESULTS

Compared with the control group, the serum Zn and Fe values of trauma patients were decreased. There was no significant difference in serum Cu between the patients and the control group. In the trauma group, the serum Zn and Fe were lower than that of the minor injury group, and the difference of Cu concentration was not statistically significant.

CONCLUSIONS

Serum Zn and Fe levels in patients with multiple trauma fractures were significantly different than those in the normal group, suggesting that Zn and Fe need to be monitored in the early stage of trauma.

Assessment of Micronutrient Status in Critically Ill Children: Challenges and Opportunities

Micronutrients refer to a group of organic vitamins and inorganic trace elements that serve many functions in metabolism. Assessment of micronutrient status in critically ill children is challenging due to many complicating factors, such as evolving metabolic demands, immature organ function, and varying methods of feeding that affect nutritional dietary intake. Determination of micronutrient status, especially in children, usually relies on a combination of biomarkers, with only a few having been established as a gold standard. Almost all micronutrients display a decrease in their serum levels in critically ill children, resulting in an increased risk of deficiency in this setting. While vitamin D deficiency is a well-known phenomenon in critical illness and can predict a higher need for intensive care, serum concentrations of many trace elements such as iron, zinc, and selenium decrease as a result of tissue redistribution in response to systemic inflammation. Despite a decrease in their levels, supplementation of micronutrients during times of severe illness has not demonstrated clear benefits in either survival advantage or reduction of adverse outcomes. For many micronutrients, the lack of large and randomized studies remains a major hindrance to critically evaluating their status and clinical significance.