Common endocrine issues in the pediatric intensive care unit

Impact of the COVID-19 pandemic on diabetic ketoacidosis management in the pediatric intensive care unit

BACKGROUND

Diabetic ketoacidosis (DKA) is a common endocrine emergency in pediatric patients. Early presentation to health facilities, diagnosis, and good management in the pediatric intensive care unit (PICU) are crucial for better outcomes in children with DKA.

METHODS

This was a single-center, retrospective cohort study conducted between February 2015 and January 2022. Patients with DKA were divided into two groups according to pandemic status and diabetes diagnosis.

RESULTS

The study enrolled 59 patients, and their mean age was 11±5 years. Forty (68%) had newly diagnosed type 1 diabetes mellitus (T1DM), and 61% received follow-up in the pre-pandemic period. Blood glucose, blood ketone, potassium, phosphorus, and creatinine levels were significantly higher in the new-onset T1DM group compared with the previously diagnosed group (P=0.01, P=0.02, P<0.001, P=0.01, and P=0.08, respectively). In patients with newly diagnosed T1DM, length of PICU stays were longer than in those with previously diagnosed T1DM (28.5±8.9 vs. 17.3±6.7 hours, P<0.001). The pandemic group was compared with pre-pandemic group, there was a statistically significant difference in laboratory parameters of pH, HCO3, and lactate and also Pediatric Risk of Mortality (PRISM) III score. All patients survived, and there were no neurologic sequelae.

CONCLUSIONS

Patients admitted during the pandemic period were admitted with more severe DKA and had higher PRISM III scores. During the pandemic period, there was an increase in the incidence of DKA in the participating center compared to that before the pandemic.

Clinical and pathophysiological aspects of impaired water and sodium metabolism in newborns and neurological complication

This literature review covers the pathophysiological features of water and sodium exchange in newborns. The main mechanisms regulating fluid and electrolyte balance in newborns are poorly studied. The volume and composition of the extracellular fluid are provided by the functional activity of the kidneys under the control of the neuroendocrine system. The antidiuretic hormone plays the main role in the regulation of water excretion by the kidneys. The volume of intracellular fluid depends on the passive water transport with the participation of aquaporins. Lability of water and electrolyte metabolism in newborns may be accompanied by hyponatremia. For various pathological conditions in the neonatal period, certain types of hyponatremias are characteristic. Correction of hyponatremia should be carried out taking into account its pathophysiological type. Hyponatremia is a common complication associated with severe neonatal brain damage. Hyponatremia contributes to brain damage as an independent factor. The study of indicators of water and electrolyte balance in the neonatal period has an important prognostic value for early detection of damage to the central nervous system.

PN Administration in Critically Ill Children in Different Phases of the Stress Response

Nutritional support is an important part of the treatment of critical ill children and the phase of disease has to be taken into account. The metabolic stress response during acute critical illness is characterized by severe catabolism. So far, there is no evidence that the acute catabolic state can be prevented with nutritional support. The Pediatric ’Early versus Late Parenteral Nutrition’ (PEPaNIC) trial showed that withholding supplemental parenteral nutrition (PN) during the first week in critically ill children, when enteral nutrition was not sufficient, prevented infections and shortened the stay in the pediatric intensive care unit (PICU) and the hospital. A follow-up performed 2 and 4 years later showed that withholding parenteral nutrition (PN) also improved several domains of the neurocognitive outcome of the children. Current international guidelines recommend considering withholding parenteral macronutrients during the first week of pediatric critical illness, while providing micronutrients. These guidelines also recommend upper and lower levels of intake of macronutrients and micronutrients if PN is administered.

Novel neutrophil phenotypic signature in pediatric patients with type 1 diabetes and diabetic ketoacidosis

Type 1 diabetes (T1D) is a chronic inflammatory condition sometimes complicated by acute diabetic ketoacidosis (DKA). A subset of patients with T1D develop DKA independent of known risk factors. This study tested the hypothesis that circulating polymorphonuclear leukocytes (PMN) from children with T1D and DKA would exhibit a primed phenotype and that the signature would be unique in patients predisposed to have DKA. Using a prospective cohort study design, neutrophil phenotype was assessed in 30 patients with T1D seen in endocrinology clinic for routine care, 30 patients with acute DKA, and 36 healthy donors. Circulating PMN from patients with DKA display a primed phenotype with increased basal cell-surface CD11b, L-selectin shedding, and enhanced fMLF-elicited reactive oxygen species (ROS) production. Moreover, PMN from T1D patients both with and without DKA lack the capacity to be further primed by incubation with TNF-α, a classic priming stimulus. Primed PMN phenotypic signatures demonstrated are independent of hemoglobin A1c, the premier biological marker for DKA risk, and are consistent with a hyperinflammatory state. A single nucleotide polymorphism in TLR-1 (1805G>T), known to be associated with a hyperinflammatory PMN phenotype, correlated with DKA. This study elucidated a novel phenotypic signature in circulating PMN from children with T1D with and without DKA, and suggests the possibility of a previously unrecognized PMN phenotype with potential clinical implications. Immunophenotype and genotype may be applicable as biomarkers for DKA risk stratification in patients with T1D.

Determinants of deranged thyroid function parameters in children admitted for management of diabetic ketoacidosis/diabetic ketosis

BACKGROUND

Euthyroid sick syndrome (ESS) frequently arises in children admitted with diabetic ketoacidosis/diabetic ketosis (DKA/DK). This study evaluates the interplay of various metabolic factors with occurrence of deranged thyroid function tests in children suffering from DKA/DK.

METHODS

98 DKA and 96 DK pediatric patients were selected from hospital records. Those on thyroxine replacement, with overt hypothyroidism, or with positive anti-thyroperoxidase (TPO) antibody were excluded. Tests for liver function, renal function, lipid profile, serum osmolarity, thyroid function, c-peptide levels, and glycosylated hemoglobin were done on all patients. Children were divided into euthyroid (n = 88) and ESS groups (n = 106).

RESULTS

The ESS group had a higher level of white blood cell count (WBC), plasma glucose (PG), beta-hydroxybutyric acid (β-HB), triglyceride (TG), anion gap (AG), glycosylated hemoglobin (HbA1c) and a lower level of HCO₃^-, prealbumin (PA), and albumin (ALB) compared with the euthyroid group (P < 0.05). Free T3 (FT3) levels were significantly correlated to β-HB, HCO₃^-, AG, PA, and HbA1c (r = - 0.642, 0.681, - 0.377, 0.581, - 0.309, respectively; P < 0.01). Free T4 (FT4) levels were significantly correlated to β-HB, HCO₃^-, and ALB levels (r = - 0.489, 0.338, 0.529, respectively; P < 0.01). TSH levels were significantly affected by HCO₃^- only (r = - 0.28; P < 0.01). HCO₃^- level was the most important factor deciding euthyroid or ESS on logistic regression analysis (OR = 0.844, P = 0.004, 95%CI = 0.751-0.948).

CONCLUSIONS

Lower levels of free thyroid hormones and occurrence of ESS were associated with a higher degree of acidosis in children with DKA/DK.

Nonthyroidal illness in critically ill children

PURPOSE OF REVIEW

This review summarizes recent literature on nonthyroidal illness syndrome (NTI) and outcome of pediatric critical illness, to provide insight in pathophysiology and therapeutic implications.

RECENT FINDINGS

NTI is typically characterized by lowered triiodothyronine levels without compensatory TSH rise. Although NTI severity is associated with poor outcome of pediatric critical illness, it remains unclear whether this association reflects an adaptive protective response or contributes to poor outcome. Recently, two metabolic interventions that improved outcome also altered NTI in critically ill children. These studies shed new light on the topic, as the results suggested that the peripheral NTI component, with inactivation of thyroid hormone, may represent a beneficial adaptation, whereas the central component, with suppressed TSH-driven thyroid hormone secretion, may be maladaptive. There is currently insufficient evidence for treatment of NTI in children. However, the recent findings raised the hypothesis that reactivation of the central NTI component could offer benefit, which should be tested in RCTs.

SUMMARY

NTI in critically ill children can be modified by metabolic interventions. The peripheral, but not the central, component of NTI may be a beneficial adaptive response. These findings open perspectives for the development of novel strategies to improve outcome of critical illness in children.

Low Value of Thyroid Testing in the Pediatric Inpatient Setting

OBJECTIVES

Our objective was to assess the frequency of pediatric inpatient thyroid testing, frequency of detection of abnormal results, and apparent impact on patient management.

METHODS

This is a retrospective study of admissions from July 2015 to June 2016 at a large urban children's hospital. Chart review was conducted on all hospitalized pediatric patients who underwent thyroid testing. We used a normal range of 0.5 to 5.0 μIU/mL for thyroid-stimulating hormone (TSH) and 1.0 to 2.0 ng/dL for free thyroxine (FT4), except for neonates for whom we used the higher reference ranges specified by the hospital laboratory.

RESULTS

Thyroid testing occurred in 1202 (5.7%) of 20 907 hospitalizations; 79.3% had combined thyroid function tests (TFTs) with TSH + FT4 being most common, and 20.6% had TSH only. Combined TFTs were ordered routinely by psychiatry and frequently by endocrine, gastrointestinal, cardiology, and neurology services, but many cases had no identified reason for testing. Of the 205 abnormal tests (17.1%), the most common abnormalities in the combined TFTs group were normal FT4 and increased TSH (35.4%) (76% of which were between 5 and 10 μIU/mL), normal FT4 and TSH 0.1 to 0.5 μIU/mL (33.1%), and high FT4 but normal TSH (14.3%). Patients with new-onset type 1 diabetes had borderline low or high TSH in about 20% of cases, but all abnormalities resolved at outpatient follow-up. Overall, 8 patients (0.66%) were started on levothyroxine.

CONCLUSIONS

Pediatric inpatient thyroid testing is relatively common at our institution, and although results are often abnormal, they do not point to thyroid disease that has contributed to the reason for hospitalization and do not identify patients in urgent need of starting therapy.

Interpreting Minor Variations in Thyroid Function or Echostructure: Treating Patients, Not Numbers or Images

Overt thyroid dysfunction is documented by serum thyrotropin or T4 concentrations are often ordered for nonspecific complaints and will by definition fall outside of the 95% reference range 5% of the time. In addition, most laboratories quote adult ranges, which are not necessarily applicable to young children, and regression toward the mean is common, justifying that the test be repeated before embarking on treatment. On the other hand, neck ultrasounds are frequently performed for diffuse goiter or non-thyroid conditions. Yet, an ultrasound is not required to make a diagnosis of Hashimoto thyroiditis and small cysts and nodules discovered incidentally often lead to unjustified concerns about neoplasia.

Stress response in critical illness

Sepsis brings about neuroendocrine dysfunction in children that differs significantly from that of adults and can thus be difficult to interpret and manage. Aggressive treatment of sepsis with appropriate and judicious use of antibiotics remains a top priority. Strict glycemic control in children has been associated with significant risk of hypoglycemia, which may independently contribute to morbidity and mortality. Timely initiation of hydrocortisone in persistently hypotensive children with fluid-refractory, catecholamine-resistant shock is controversial, but its use in children with suspected or proven adrenal insufficiency is suggested. Fluid and electrolyte abnormalities must be corrected. Treatment of thyroid dysfunction has been shown to be beneficial in certain specific populations but cannot be extrapolated to all septic patients with the current available data.