Infants Diagnosed with Athyreosis on Scintigraphy May Have a Gland Present on Ultrasound and Have Transient Congenital Hypothyroidism

Scintigraphy using technetium-99m (99mTc) is the gold standard for imaging the thyroid gland in infants with congenital hypothyroidism (CHT) and is the most reliable method of diagnosing an ectopic thyroid gland. One of the limitations of scintigraphy is the possibility that no uptake is detected despite the presence of thyroid tissue, leading to the spurious diagnosis of athyreosis. Thyroid ultrasound is a useful adjunct to detect thyroid tissue in the absence of 99mTc uptake.

AIMS

We aimed to describe the incidence of sonographically detectable in situ thyroid glands in infants scintigraphically diagnosed with athyreosis using 99mTc and to describe the clinical characteristics and natural history in these infants.

METHODS

The newborn screening records of all infants diagnosed with CHT between 2007 and 2016 were reviewed. Those diagnosed with CHT and athyreosis confirmed on scintigraphy were invited to attend a thyroid ultrasound.

RESULTS

Of the 488 infants diagnosed with CHT during the study period, 18/73 (24.6%) infants with absent uptake on scintigraphy had thyroid tissue visualised on ultrasound (3 hypoplastic thyroid glands and 15 eutopic glands). The median serum thyroid-stimulating hormone (TSH) concentration at diagnosis was significantly lower than that in infants with confirmed athyreosis (no gland on ultrasound and no uptake on scintigraphy) (74 vs. 270 mU/L), and median free T4 concentration at diagnosis was higher (11.9 vs. 3.9 pmol/L). Six of 10 (60%) infants with no uptake on scintigraphy but a eutopic gland on ultrasound had transient CHT.

CONCLUSION

Absent uptake on scintigraphy in infants with CHT does not rule out a eutopic gland, especially in infants with less elevated TSH concentrations. Clinically, adding thyroid ultrasound to the diagnostic evaluation of infants who have athyreosis on scintigraphy may avoid committing some infants with presumed athyreosis to lifelong levothyroxine treatment.

Provocative growth hormone testing in children: how did we get here and where do we go now?

OBJECTIVES

Provocative growth hormone (GH) tests are widely used for diagnosing pediatric GH deficiency (GHD). A thorough understanding of the evidence behind commonly used interpretations and the limitations of these tests is important for improving clinical practice.

CONTENT

To place current practice into a historical context, the supporting evidence behind the use of provocative GH tests is presented. By reviewing GH measurement techniques and examining the early data supporting the most common tests and later studies that compared provocative agents to establish reference ranges, the low sensitivity and specificity of these tests become readily apparent. Studies that assess the effects of patient factors, such as obesity and sex steroids, on GH testing further bring the appropriateness of commonly used cutoffs for diagnosing GHD into question.

SUMMARY AND OUTLOOK

Despite the widely recognized poor performance of provocative GH tests in distinguishing GH sufficiency from deficiency, limited progress has been made in improving them. New diagnostic modalities are needed, but until they become available, clinicians can improve the clinical application of provocative GH tests by taking into account the multiple factors that influence their results.

Racial/Ethnic Disparities in the Investigation and Treatment of Pediatric Growth Hormone Deficiency

Introduction: In the United States, non-Hispanic white (NHW) children are disproportionately over-represented relative to children of racial and ethnic minorities in pediatric growth hormone (GH) treatment registries. This study sought to determine if this racial inequity is due to differences in GH stimulation testing and/or GH prescribing patterns in children referred for endocrine evaluation of short stature.

Methods: Retrospective chart review was performed including children aged 2-16 years, with height z-score ≤ -1.5, and of NHW, non-Hispanic black (NHB) or Hispanic race/ethnicity, referred for endocrine growth evaluation between January 1, 2012 and December 31, 2019. Age, sex, anthropometry, GH stimulation test results and GH treatment data were extracted. Comparisons between NHB, NHW and Hispanic children were performed using analysis of variance, chi-squared tests, Mann Whitney U and logistic regression tests.

Results: This study included 7,425 patients (5,905 NHW, 800 NHB, and 720 Hispanic). GH stimulation testing was performed in 992, and 576 were prescribed GH. NHW children were 1.4 (95% CI 1.04 - 1.8) times more likely than NHB children and 1.7 (95% CI 1.2 - 2.2) times more likely than Hispanic children to undergo GH stimulation testing. NHB children treated with GH had: 1) lower median peak GH concentration when compared with NHW (p=0.02) and Hispanic (p=0.08) children (NHB 4.7 [1.2, 8.3] ng/ml, NHW 7.2 [4.9, 9.7] ng/ml, Hispanic 7.1 [4.3, 11.9] ng/ml); 2) lower median height z-scores than NHW (p=0.01) but not Hispanic children (p=0.5); and 3) a greater height deficit from mid-parental height when compared with NHW (p=0.01) and Hispanic (p=0.002) children

Discussion: Racial and ethnic disparities are present in the evaluation and treatment of children with disordered growth. This likely results from both over-investigation of NHW children as well as under-investigation and under-treatment of children from minority communities. The evaluation and treatment of children with short stature should be determined by clinical concern alone, but this is unfortunately not current practice.

Growth Hormone Stimulation Testing Patterns Contribute to Gender Disparities in Growth Hormone Treatment

Introduction: Growth hormone (GH) registries demonstrate that males outnumber females 2:1 for all indications combined and 3:1 for the idiopathic short stature indication. The aim of this study was to determine if gender disparities in GH treatment are due to differences in rates of stimulation testing and/or GH prescribing. Methods: Retrospective chart review was performed including children aged 2-16 years seen for short stature or poor growth in 2012-2019 at a large tertiary referral center. Children previously diagnosed with GHD were excluded. Continuous variables, reported as medians [IQR], were compared by Wilcoxon rank sum test and categorical variables by Chi-squared test. A two-tailed p-value <0.05 defined statistical significance. Results: Of 10,125 children seen for evaluation of short stature or poor growth (35% [3542] females [F], 65% [6583] males [M]), 1,245 underwent GH stimulation testing (30% [379] F, 70% [866] M). A larger proportion of males than females were tested (M 13.2%, F 10.7%; p <0.001). Amongst the entire study population, females had lower height Z-scores than males (F -1.98 [-2.46, -1.44], M -1.80 [-2.24, -1.31]; p<0.001). This difference persisted in those who proceeded to GH stimulation testing (F -2.52 [-3.00, -2.04], M -2.18 [-2.6, -1.81]; p<0.001) and GH treatment (F -2.62 [-3.11, -2.07], M -2.19 [-2.60, -1.81; p<0.001). Mean difference between height Z-score and mid-parental height (MPH) Z-score for the entire population did not differ by sex (F -1.52 [-2.17, -0.87], M -1.52 [-2.04, -0.97]; p=0.76), but the difference was greater in females among those who underwent GH stimulation testing (F -1.95 [-2.57, -1.40], M -1.79 [-2.32, -1.32]; p=0.009) and started GH treatment (F -1.93 [-2.58, -1.48], M -1.80 [-2.30, -1.32]; p=0.016). Peak stimulated GH levels were similar for males and females (F 9.6 [6.0, 13.6] ng/mL, M 9.4 [6.1, 13.2] ng/mL, p=0.62). The proportion of children prescribed GH after stimulation testing did not differ by gender (F 55% [208], M 56% [488]; p=0.63). This finding did not change upon sub-analysis by peak stimulated GH concentration groups (peak GH concentrations <7 ng/mL, 7-10 ng/mL, and >10 ng/mL). Conclusion: The male predominance among children seen for subspecialist evaluation of short stature was compounded by a greater proportion of those males subsequently undergoing GH stimulation testing despite less severe short stature. Although females who underwent GH stimulation testing had greater height deficit from their genetic potential than tested males, peak stimulated GH concentrations and GH prescription rates were similar by sex. Thus, gender disparities in GH treatment occur at the subspecialist referral and stimulation testing, but not GH prescription, steps. Further, GH stimulation test results failed to account for the more severe shortness among tested females, yet another limitation identified with such testing.

Growth Hormone Stimulation Testing Patterns Contribute to Sex Differences in Pediatric Growth Hormone Treatment

INTRODUCTION

Males are twice as likely as females to receive pediatric growth hormone (GH) treatment in the USA, despite similar distributions of height z (HtZ)-scores in both sexes. Male predominance in evaluation and subspecialty referral for short stature contributes to this observation. This study investigates whether sex differences in GH stimulation testing and subsequent GH prescription further contribute to male predominance in GH treatment.

METHODS

Retrospective chart review was conducted of all individuals, aged 2-16 years, evaluated for short stature or poor growth at a single large tertiary referral center between 2012 and 2019. Multiple logistic regression models were constructed to analyze sex differences.

RESULTS

Of 10,125 children referred for evaluation, a smaller proportion were female (35%). More males (13.1%) than females (10.6%) underwent GH stimulation testing (p < 0.001) and did so at heights closer to average (median HtZ-score -2.2 [interquartile range, IQR -2.6, -1.8] vs. -2.5 [IQR -3.0, -2.0], respectively; p < 0.001). The proportion of GH prescriptions by sex was similar by stimulated peak GH level. Predictor variables in regression modeling differed by sex: commercial insurance predicted GH stimulation testing and GH prescription for males only, whereas lower HtZ-score predicted GH prescription for females only.

CONCLUSIONS

Sex differences in rates of GH stimulation testing but not subsequent GH prescription based on response to GH stimulation testing seem to contribute to male predominance in pediatric GH treatment. That HtZ-score predicted GH prescription in females but not males raises questions about the extent to which sex bias - from children, parents, and/or physicians - as opposed to objective growth data, influence medical decision-making in the evaluation and treatment of short stature.

Recombinant human parathyroid hormone (1-84) is effective in CASR-associated hypoparathyroidism

INTRODUCTION

Gain-of-function mutations in the CASR gene cause Autosomal Dominant Hypocalcemia Type 1 (ADH1), the most common genetic cause of isolated hypoparathyroidism. Subjects have increased calcium sensitivity in the renal tubule, leading to increased urinary calcium excretion, nephrocalcinosis and nephrolithiasis when compared with other causes of hypoparathyroidism. The traditional approach to treatment includes activated vitamin D but this further increases urinary calcium excretion.

METHODS

In this case series, we describe the use of recombinant human parathyroid hormone (rhPTH)1-84 to treat subjects with ADH1, with improved control of serum and urinary calcium levels.

RESULTS

We describe two children and one adult with ADH1 due to heterozygous CASR mutations who were treated with rhPTH(1-84). Case 1 was a 9.4-year-old female whose 24-h urinary calcium decreased from 7.5 to 3.9 mg/kg at 1 year. Calcitriol and calcium supplementation were discontinued after titration of rhPTH(1-84). Case 2 was a 9.5-year-old male whose 24-h urinary calcium decreased from 11.7 to 1.7 mg/kg at 1 year, and calcitriol was also discontinued. Case 3 was a 24-year-old female whose treatment was switched from multi-dose teriparatide to daily rhPTH(1-84). All three subjects achieved or maintained target serum levels of calcium and normal or improved urinary calcium levels with daily rhPTH(1-84) monotherapy.

CONCLUSIONS

We have described three subjects with ADH1 who were treated effectively with rhPTH(1-84). In all cases, hypercalciuria improved by comparison to treatment with conventional therapy consisting of calcium supplementation and calcitriol.

Sitting Height to Standing Height Ratio Reference Charts for Children in the United States

OBJECTIVE

To create reference charts for sitting height to standing height ratio (SitHt/Ht) for children in the US, and to describe the trajectory of SitHt/Ht during puberty.

STUDY DESIGN

This was a cross-sectional study using data from the 1988-1994 National Health and Nutrition Examination Survey III, a strategic random sample of the US population. Comparison between non-Hispanic White (NHW), non-Hispanic Black (NHB) and Mexican American groups was performed by ANOVA to determine if a single population reference chart could be used. ANOVA was used to compare SitHt/Ht in pre-, early, and late puberty.

RESULTS

NHANES III recorded sitting height and standing height measurements in 9569 children aged 2-18 years of NHW (n = 2715), NHB (n = 3336), and Mexican American (n = 3518) ancestry. NHB children had lower SitHt/Ht than NHW and Mexican American children throughout childhood (P < .001). In both sexes, the SitHt/Ht decreased from prepuberty to early puberty and increased in late puberty. Sex-specific percentile charts of SitHt/Ht vs age were generated for NHB and for NHW and Mexican American youth combined.

CONCLUSIONS

SitHt/Ht assessment can detect disproportionate short stature in children with skeletal dysplasia, but age-, sex-, and population-specific reference charts are required to interpret this measurement. NHB children in the US have significantly lower SitHt/Ht than other children, which adds complexity to interpretation. We recommend the use of standardized ancestry-specific reference charts in screening for skeletal dysplasias and have developed such charts in this study.

Leg length and sitting height reference data and charts for children in the United States

Population-specific reference data are required to interpret growth measurements in children. Sitting height and leg length (standing height minus sitting height) measurements are indicators of proportionality and can be used to evaluate children with disordered growth. NHANES III recorded sitting height and standing height measurements in a strategic random sample of the United States population from 1988 to 1994, and we have previously published reference charts for sitting height to standing height ratio in this population. In this study, we have developed separate sitting height and leg length reference charts for Non-Hispanic Black, Non-Hispanic White, and Mexican-American children in the United States. In addition, we provide mean (SD) and LMS data to support the use of these reference charts in clinical care.

Optimal Timing of Repeat Newborn Screening for Congenital Hypothyroidism in Preterm Infants to Detect Delayed Thyroid-Stimulating Hormone Elevation

OBJECTIVES

To evaluate the timing of a delayed rise in thyroid-stimulating hormone (TSH) levels in preterm infants with congenital hypothyroidism, and to determine whether cases of congenital hypothyroidism would be missed by using current consensus guidelines of repeat screening at approximately 2 weeks of age or 2 weeks after the first screening.

STUDY DESIGN

The study was performed over a 13-year period (January 2004-December 2016). Whole-blood TSH samples were collected between 72 and 120 hours after birth. Repeat samples were collected weekly in preterm infants until the infant was term-corrected (37 weeks' gestation). Patients were followed up to determine whether congenital hypothyroidism was permanent or transient.

RESULTS

Twenty-seven (50.9%) preterm infants born at <33 weeks of gestation who were diagnosed with congenital hypothyroidism had delayed TSH elevation and would not have been detected on first newborn screen. Twelve of these infants (40.7%) with delayed TSH elevation had decompensated hypothyroidism at diagnosis (free thyroxine [FT4] <10 pmol/L), and 4 had severe congenital hypothyroidism (FT4 <5.5 pmol/L) at diagnosis. If screening had been repeated only at 2 weeks of life, 13 infants (48%) with delayed TSH elevation would not have been identified. Of the 27 infants with delayed TSH elevation, 6 (22%) have permanent congenital hypothyroidism, and another 12 will be reevaluated at age 3 years.

CONCLUSION

Repeat screening for congenital hypothyroidism in preterm infants is necessary to avoid missing cases of congenital hypothyroidism with delayed TSH elevation. Repeat screening once at 2 weeks of life will miss infants with delayed TSH elevation and decompensated permanent congenital hypothyroidism.

Fat-bone interaction within the bone marrow milieu: Impact on hematopoiesis and systemic energy metabolism

The relationship between fat, bone and systemic metabolism is a growing area of scientific interest. Marrow adipose tissue is a well-recognized component of the bone marrow milieu and is metabolically distinct from current established subtypes of adipose tissue. Despite recent advances, the functional significance of marrow adipose tissue is still not clearly delineated. Bone and fat cells share a common mesenchymal stem cell (MSC) within the bone marrow, and hormones and transcription factors such as growth hormone, leptin, and peroxisomal proliferator-activated receptor γ influence MSC differentiation into osteoblasts or adipocytes. MSC osteogenic potential is more vulnerable than adipogenic potential to radiation and chemotherapy, and this confers a risk for an abnormal fat-bone axis in survivors following cancer therapy and bone marrow transplantation. This review provides a summary of data from animal and human studies describing the relationship between marrow adipose tissue and hematopoiesis, bone mineral density, bone strength, and metabolic function. The significance of marrow adiposity in other metabolic disorders such as osteoporosis, diabetes mellitus, and estrogen and growth hormone deficiency are also discussed. We conclude that marrow adipose tissue is an active endocrine organ with important metabolic functions contributing to bone energy maintenance, osteogenesis, bone remodeling, and hematopoiesis. Future studies on the metabolic role of marrow adipose tissue may provide the critical insight necessary for selecting targeted therapeutic interventions to improve altered hematopoiesis and augment skeletal remodeling in cancer survivors.

Glargine co-administration with intravenous insulin in pediatric diabetic ketoacidosis is safe and facilitates transition to a subcutaneous regimen

BACKGROUND

Diabetes ketoacidosis (DKA) is a common presentation and complication of type 1 diabetes (T1D). While intravenous insulin is typically used to treat acute metabolic abnormalities, the transition from intravenous to subcutaneous treatment can present a challenge. We hypothesize that co-administration of glargine, a subcutaneous long-acting insulin analog, during insulin infusion may facilitate a flexible and safe transition from intravenous to subcutaneous therapy.

OBJECTIVE

To determine if the practice of administering subcutaneous glargine during intravenous insulin is associated with an increased risk of hypoglycemia, hypokalemia, or other complications in children with DKA.

METHODS

Retrospective chart review of patients aged 2 to 21 years, presenting to our center with DKA between April 2012 and June 2014. Patients were divided into two groups: those co-administered subcutaneous glargine with intravenous insulin for over 4 hours (G+); and patients with less than 2 hours of overlap (G-).

RESULTS

We reviewed 149 DKA admissions (55 G+, 94 G-) from 129 unique patients. There was a similar incidence of hypoglycemia between groups (25% G+ vs 20% G-, P = 0.46). Hypokalemia (<3.5 mmol/L) occurred more frequently in the G+ group (OR = 3.4, 95% CI 1.7-7.0, P = 0.001). Cerebral edema occurred in 2/55 (3.6%) of the G- group and none of the G+ subjects.

CONCLUSION

Co-administration of glargine early in the course of DKA treatment is well tolerated and convenient for discharge planning; however, this approach is associated with an increased risk of hypokalemia.

CYP3A4 Induction by Rifampin: An Alternative Pathway for Vitamin D Inactivation in Patients With CYP24A1 Mutations

Context

The P450 enzyme CYP24A1 is the principal inactivator of vitamin D metabolites. Biallelic loss-of-function mutations in CYP24A1 are associated with elevated serum levels of 1,25-dihydroxyvitamin D3 with consequent hypercalcemia and hypercalciuria and represent the most common form of idiopathic infantile hypercalcemia (IIH). Current management strategies for this condition include a low-calcium diet, reduced dietary vitamin D intake, and limited sunlight exposure. CYP3A4 is a P450 enzyme that inactivates many drugs and xenobiotics and may represent an alternative pathway for inactivation of vitamin D metabolites.

Objective

Our goal was to determine if rifampin, a potent inducer of CYP3A4, can normalize mineral metabolism in patients with IIH due to mutations in CYP24A1.

Methods

We treated two patients with IIH with daily rifampin (10 mg/kg/d, up to a maximum of 600 mg). Serum calcium, phosphorus, parathyroid hormone (PTH), liver, and adrenal function and vitamin D metabolites, as well as urinary calcium excretion, were monitored during treatment of up to 13 months.

Results

Prior to treatment, both patients had hypercalcemia, hypercalciuria, and nephrocalcinosis with elevated serum 1,25-dihydroxyvitamin D3 and suppressed serum PTH. Daily treatment with rifampin was well tolerated and led to normalization or improvement in all clinical and biochemical parameters.

Conclusion

These observations suggest that rifampin-induced overexpression of CYP3A4 provides an alternative pathway for inactivation of vitamin D metabolites in patients who lack CYP24A1 function.

A National Survey on the Diagnosis and Treatment of Paediatric Growth Hormone Deficiency

Many countries have established regulations regarding growth hormone (GH) treatment in children, to standardise care and reduce cost. In this study, we describe current practice in Ireland surrounding child measurement and the approach to diagnosis of GH deficiency. A questionnaire was sent to 139 paediatricians in Ireland and 35 (9 paediatric endocrinologists) responded. Only 13 (37.1%) use the recommended 2-person technique for measuring children under 2. Amongst GH prescribers, there were a variety of GH Stimulation Tests used, sex steroid priming was used by 8 (80%) and the general cut off for a passed test was consistent (7ng/ml). Brand rotation (n=5, 50%) and cost (n=3, 30%) were the most common criteria for deciding the formulation of GH prescribed. We recommend that departments review their child measurement technique and equipment. We also advise the establishment of national guidelines for the use of GH, and a prospective registry for GH treated children.

Auscultate, palpate and tap: time to re-evaluate

AIM

To determine the accuracy of current methods of heart rate (HR) assessment.

METHODS

All participants palpated a simulated pulsating umbilicus (UMB), listened to a tapping rate (TAP) and auscultated a simulated HR (AUSC). A simulated HR of 54, 88 and 128 beats per minute (bpm) was randomised for all methods.

RESULTS

Twenty-nine healthcare staff participated in this study. Correct assessment of HR of 54 bpm as being within the 0-59 range occurred in 17.2% UMB, 17.2% TAP and 31% AUSC and was obtained in <10 seconds by 48.3%, 65.5% and 62.1%, respectively. A rate of 88 bpm was correctly assessed as within the 60-100 range in 82.8% UMB, 79.3% TAP and 79.3% AUSC and was obtained in <10 seconds by 55.2%, 58.6% and 55.2%, respectively. A rate of 128 bpm was identified as >100 bpm by 96.6% UMB, 93.1% TAP, and 93.1% AUSC and was obtained in <10 seconds by 51.7%, 55.2% and 62.1%, respectively.

CONCLUSION

Current methods in assessing rates below 60 bpm are inaccurate and may overestimate HR. We recommend that these methods alone should not be relied upon in neonatal resuscitation and objective assessment of heart rate should be readily available at all newborn resuscitations.

Late Presentation of Fulminant Necrotizing Enterocolitis in a Child with Hyperinsulinism on Octreotide Therapy

Congenital hyperinsulinism (HI) is the most common cause of persistent hypoglycemia in infants and children. In cases of diazoxide-unresponsive HI, alternative medical and surgical approaches may be required to reduce the risk of hypoglycemia. Octreotide, a somatostatin analog, often has a role in the management of these children, but a dose-dependent reduction in splanchnic blood flow is a recognized complication. Necrotizing enterocolitis (NEC) has been reported within the first few weeks of initiating predominantly high doses of octreotide. We describe the case of an infant with Beckwith-Wiedemann syndrome and diazoxide-unresponsive HI, who had persistent hypoglycemia after two pancreatectomy surgeries. She developed NEC 2 months after beginning octreotide therapy at a relatively low dose of 8 µg/kg/day. This complication has occurred later, and at a lower dose, than has previously been described. We review the case and identify the known and suspected multifactorial risk factors for NEC that may contribute to the development of this complication in patients with HI.

Serial GH Measurement After Intravenous Catheter Placement Alone Can Detect Levels Above Stimulation Test Thresholds in Children

CONTEXT

GH stimulation testing is limited by poor specificity and reproducibility in identifying GH deficiency. Intravenous line placement (IVP) in pediatrics may be a stimulus for GH secretion.

OBJECTIVE

The objective of the study was to determine whether the measurement of GH at baseline as well as 15 and 30 minutes after IVP detects additional patients with sufficient peak GH concentrations who are not identified by a subsequent insulin tolerance test (ITT).

METHODS

The ITT protocol was modified to include GH measurement at the time of IVP (t = 0) and 15 (t = 15) and 30 (t = 30) minutes later. Insulin was administered at t = 30, and an ITT was performed as per standard protocols. Children were grouped according to the indication for ITT: initial evaluation of GH deficiency (group 1); and GH deficiency at transition to adulthood (group 2).

RESULTS

Ninety-seven patients were included (76 in group 1, 21 in group 2). Of these, 27 (28%) had a peak GH concentration of 7 ng/mL or greater (19 in group 1, eight in group 2) either after IVP or ITT. Thirteen subjects (11 in group 1, two in group 2) had GH concentrations of 7 ng/mL or greater after IVP, without exceeding this on a subsequent ITT. Among the 11 group 1 patients, three of these GH peaks of 7 ng/mL or greater occurred at t = 0, 5 at t = 15, and 5 at t = 30, including one patient who had a peak GH of 7 ng/mL or greater at all three time points.

CONCLUSION

Some children will not have a sufficient GH response to pharmacological stimuli but will have a robust response to IVP. We recommend GH measurement after IVP in children undergoing GH stimulation testing, particularly when there is a delay between IVP and the administration of the pharmacological stimulus.

Fear of hypoglycemia in parents of children with type 1 diabetes

AIM

The aim of this study is to determine if parental hypoglycaemia fear is associated with worse glycaemic control and increased resource utilisation and to identify risk factors for increased hypoglycaemia fear.

METHODS

Parents of children with diabetes completed a modified Hypoglycaemia Fear Survey. Demographic data, phone contacts and mean glycosylated haemoglobin A1c (HbA1c) were also recorded over a 1 year study period.

RESULTS

A total of 106 parents participated. Mean patient age was 11.1 years, and duration of diabetes was 4.8 years. Fifty-two per cent were male, and 48% were on insulin pump therapy. Fear of hypoglycaemia was highest among parents of 6- to 11-year-olds. Parents of children with HbA1c less than 7.5% had less hypoglycaemia fear. Previous seizures and increased frequency of phone calls to the diabetes team were not associated with increased fear.

CONCLUSION

Fear of hypoglycaemia is associated with worse glycaemic control. It is highest among parents of 6- to 11-year-olds but is not affected by previous severe hypoglycaemia or associated with increased contact with the diabetes team.

Is the NHS best practice tariff for type 1 diabetes applicable in the Irish context?

The National Health Service in the UK has identified thirteen key standards of paediatric diabetes care. Funding depends on services meeting these standards. The aim of this study was to determine if these standards are applicable in an Irish setting. All patients attending the diabetes service during 2012 were included. Patient charts, electronic appointments, nursing notes and computerised results were used to ascertain relevant information for comparison with the NHS standards. Patients attended a mean 2.97 (SD 0.7) medical and 2.2 (SD 2.9) nursing appointments per year, with a median additional contacts of 8 nurse phone calls (range 0 - 125). Most standards were met by this service. In comparing our service to the NHS standard, we have identified a number of areas for improving our service provision. Limited resources and staff shortages make a number of these standards unachievable, namely annual dietetic review and three monthly outpatient appointments.

Ketotic hypercalcemia: a case series and description of a novel entity

CONTEXT

The ketogenic diet is increasingly used in refractory epilepsy and is associated with clinically significant effects on bone and mineral metabolism. Although hypercalciuria and loss of bone mineral density are common in patients on the ketogenic diet, hypercalcemia has not previously been described.

OBJECTIVE

The aim of the study was to describe three children who developed hypercalcemia while on the ketogenic diet.

DESIGN

A retrospective chart review of three children on the ketogenic with severe hypercalcemia was conducted.

RESULTS

We describe three children on the ketogenic diet for refractory seizures who presented with hypercalcemia. Case 1 was a 5.5-year-old male with an undiagnosed, rapidly progressive seizure disorder associated with developmental regression. Case 2 was a 2.5-year-old male with a chromosomal deletion of 2q24.3, and case 3 was a 4.6-year-old male with cerebral cortex dysplasia. Patients had been on a ketogenic diet for 6 to 12 months before presentation. Daily intake of calcium and vitamin D was not excessive, and all three patients were not acidotic because they were taking supplemental bicarbonate. Each child had elevated serum levels of calcium and normal serum phosphate levels, moderately elevated urinary calcium excretion, and low levels of serum alkaline phosphatase, PTH, and 1,25-dihydroxyvitamin D. All patients responded to calcitonin.

CONCLUSIONS

Hypercalcemia is an uncommon complication of the ketogenic diet, and these children may represent the severe end of a clinical spectrum of disordered mineral metabolism. The mechanism for hypercalcemia is unknown but is consistent with excess bone resorption and impaired calcium excretion.

Difficulties associated with diabetes management during the Junior Certificate examination

The aim of this study was to describe the adherence to recommended diabetes care during the Junior Certificate, and the utilisation of available allowances for children with type 1 diabetes. Questionnaires were sent within 3 months of the examination to all adolescents and their families attending our service completing the Junior Certificate in June of 2012. Fifteen of the 25 (60%) patients/parents completed the questionnaires. Five (33%) had higher than usual glucose readings during the examination period and three (20%) experienced hypoglycaemia during at least one exam. Nine (60%) never checked capillary glucose levels during the exams. No patients left the examination area to perform diabetes related tasks. Thirteen (86%) brought fast acting glucose into the examination centre while only six (40%) brought a glucometer. Just four (27%) patients availed of the rest breaks allowed and six (40%) felt that their diabetes affected their examination performance.

Paediatric type 1 diabetes in Ireland--results of the first national audit

The aim of this study was to describe the services provided for children with type 1 diabetes in the Republic of Ireland, and to identify a baseline from which services and outcomes might be improved. Lead clinicians in 17 of the 19 centres providing paediatric type 1 diabetes care responded to requests for information from 2012 regarding demographics, patient numbers, diagnostics, outpatient management, multidisciplinary team resources, comorbidity screening, transition policy, clinical guidelines, and use of insulin pumps. The total number of patients attending these centres was 2518. Eight centres initiate insulin pump therapy. Insulin pump usage ranged from 0 to 42% of patients attending each centre. Self reported clinic mean haemoglobin A1c ranged from 8.2 to 9.4% (66.1 to 79.2 mmol/mol). Variation existed in guideline availability, frequency of clinic appointments, age of transition and insulin types used. We recommend a national approach to standardising and improving care for these patients.

The evolving course of HNF4A hyperinsulinaemic hypoglycaemia--a case series

BACKGROUND

Hepatocyte nuclear factor 4 alpha (HNF4A) gene mutations have a well-recognized role in maturity-onset diabetes of the young and have recently been described in congenital hyperinsulinism. A biphasic phenotype has been postulated, with macrosomia and congenital hyperinsulinism in infancy, and diabetes in young adulthood. In this case series, we report three children with HNF4A mutations (two de novo) and diazoxide-responsive congenital hyperinsulinism, highlighting the potential for ongoing diazoxide requirement and the importance of screening for these mutations even in the absence of family history.

CASE REPORTS

All patients presented with macrosomia (mean birthweight 4.26 kg) and hyperinsulinaemic hypoglycaemia soon after birth (median age 1 day). All three (age range 7 months to 11 years 10 months) remain on diazoxide therapy, with dose requirements increasing in one patient. There was no prior family history of diabetes, neonatal hypoglycaemia or macrosomia. Parents were screened for HNF4A mutations post-diagnosis and one father was subsequently found to have maturity-onset diabetes of the young.

CONCLUSIONS

This case series follows the evolving course of three patients with confirmed HNF4A-mediated congenital hyperinsulinism, highlighting (1) the variable natural history of these mutations, (2) the potential for prolonged diazoxide requirement, even into adolescence, and (3) the need for screening, regardless of family history.

Measuring growth hormone and insulin-like growth factor-I in infants: what is normal?

The role of growth hormone (GH) and insulinlike growth factor-I (IGF-I) change through early childhood. Whereas poor growth is a later presenting feature, infants with isolated GH deficiency have a normal birth weight and length, and often present with hypoglycemia. IGF-I plays an important role antenatally and post-natally in somatic and brain growth. In order to evaluate the GH/IGF-I axis in infancy, an understanding of the normal physiology is required. Measurements of GH and IGF-I in this population should be interpreted in the context of the assays used, as well as their limitations. In this review, we summarize our current understanding of normal GH and IGF-I secretion in children under 18 months of age, and describe variations in the reported assay-specific measurements.

Efficacy and user preference of two CO2 detectors in an infant mannequin randomized crossover trial

Assessment of effective ventilation in neonatal mask ventilation can be difficult. This study aims to determine whether manual ventilation with a T-piece resuscitator containing an inline CO2 detector (either a Pedi-Cap® CO2 detector or a Neo-StatCO2 <Kg® CO2 detector connected to a facemask) facilitates effective positive pressure ventilation compared to no device in a mannequin study. Paediatric and neonatal trainees were randomly assigned to determine which method they began with (no device, Pedi-Cap or a Neo-Stat). The participants used each method for a period of 3 min. They were video-recorded to determine the amount of effective ventilations delivered and the overall percentage efficiency of each method. Efficacy of ventilation was determined by comparing the number of manual ventilations delivered with the number of times chest rise was observed in the video recording. There were 19 paediatric trainees who provided a total of 7,790 ventilations, and 93% were deemed effective. The percentage of effective ventilations with the T-piece resuscitator alone, the PediCap and the NeoStat were 90, 94 and 96%, respectively. The difference was greatest in the first minute (T-piece resuscitator alone 87.5%, PediCap 94%, NeoStat 96%). Two thirds preferred the Neo-Stat. The use of a CO2 detector improves positive pressure ventilation in a mannequin model, especially in the first minute of positive pressure ventilation. The Neo-Stat CO2 detector was the preferred device by the majority of the participants.

Perfusion index in the very preterm infant

AIM

Perfusion Index (PI) is a quantifiable measurement of peripheral perfusion and may be a useful adjunct to the assessment of circulatory status in the newborn. (i) To assess reproducibility of PI and (ii) To determine whether there is a difference between simultaneously obtained limb measurements of PI in newborns <32 weeks GA in the transitional period.

METHODS

Perfusion Index was measured in newborns <32 weeks during the first 48 h of life. To examine reproducibility, the pulse oximetry probe was replaced on the same limb consecutively by the same operator. Upper and lower limbs were then simultaneously evaluated over a 5-min period. Heart rate, blood pressure, birth weight, ventilation requirement, inotrope use, lactate, PCO2 and CRIB-II score were also recorded.

RESULTS

Thirty infants were assessed. Intraclass correlation coefficient for reproducibility in the same limb was high (r value = 0.982 p < 0.001). Measurements obtained in the right upper limb were consistently higher than either lower limb. The median (IQR) PI for the entire cohort was 0.70 (0.29-1.35). No correlation existed between gestational age, birth weight, CRIB scores, systolic and diastolic blood pressure, mean blood pressure and median PI values.

CONCLUSION

Perfusion Index measurement is reproducible, and values are highest in the right upper limb. Wide differences between right upper and lower limb readings are most likely related to transitional circulatory changes.

Short stature in child with early-onset diabetes

We present a girl who initially presented at 12 weeks of age with antibody negative diabetes. Genetic screening for common mutations of monogenic diabetes was negative. She was noted to have short stature at 8 years of age (height <0.4 centile), as well as overlapping toes and distal abnormalities of her fingers. On reevaluation, further investigation revealed an EIF2AK3 mutation, and a diagnosis of Wolcott Rallison syndrome was made. This case highlights the importance of close follow up of patients with neonatal diabetes for the development of syndromic features that may lead to a unifying diagnosis.

Your diagnosis? Congenital foot drop

A term infant was noted to have right-sided foot drop. We discuss the role of neurophysiology and diagnostic imaging.

In vitro comparison of neonatal suction catheters using simulated 'pea soup' meconium

BACKGROUND

A variety of suction catheters (type, size and design) are recommended for oropharyngeal suctioning of meconium during newborn resuscitation, but it is not known which performs best. In this study we compared different sizes of soft catheters, the Yankauer (YK) and the portable bulb syringe (BS), in suctioning a solution of varying viscosity.

METHODS

Simulated meconium (SM) was made using commercial canned pea soup in two strengths, full-strength thick-particulate (TP) and 50% strained soup diluted with water, that is, thin-non-particulate (TnP), with saline as a control. A 20 ml aliquot of solution was suctioned over 5 s with each device using an electrical suction pump set at two different pressures, 100 and 150 mm Hg (21 kpa). In addition, the negative pressure of five BSs was measured in order to compare generated pressures with the alternative devices.

RESULTS

The YK and BS suctioned almost 100% of saline, while the 6F and 8F catheters suctioned 50% and 75% saline, respectively. The YK suctioned 100% of TnP, saline and 30% of TP. At reduced suction pressures (100 and 50 mm Hg) the YK also suctioned all TnP. The 12F and 14F catheters suctioned a minimal amount of TP, whereas YK was the most efficient, suctioning 30% of TP. The mean negative pressure generated with five BSs was 78 and 71 mm Hg by a male and female operator, respectively.

CONCLUSIONS

The YK and BS outperform the catheters in suctioning SM. The YK is the best for TP, but all devices perform poorly in suctioning fluid of this consistency.

Parental patterns of use of over the counter analgesics in children

Over-The-Counter Analgesics (OTCA) account for over a fifth of Irish pharmacy sales. Little is known about patterns of use, specifically in children. This study investigated parents' use of OTCAs in children. A questionnaire exploring use of OTCAs and knowledge of side-effects was distributed to guardians of children attending three GP surgeries in South of Ireland from June-September 2010. The questionnaire was completed by 183 parents (response rate 95%). Many respondents (n = 121, 66.1%) were using analgesics when not required or using an inappropriate analgesic for a child's symptom. Private patients demonstrated better use (n = 31, 40%) than those with Medical Cards (n = 18, 22.5%) (p = 0.016). Identification of potential side-effects was poor, with drowsiness (n = 88, 49%), rash (n = 39, 22%) and nausea (n =3 2, 18%) listed as potential side-effects. Inappropriate use of OTCAs is prevalent in Irish children. Parents need more information and guidance on their use.

Congenital sacrococcygeal PNET and chemotherapy

We present the case of a congenital localised sacrococcygeal primitive neuroectodermal tumor treated aggressively with surgical resection and modified age-appropriate adjuvant chemotherapy. The conventional combination chemotherapy of vincristine, adriamycin, cyclophosphamide, ifosfamide and etoposide was modified to a regimen including vincristine, adriamicin, cyclophosphamide and actinomycin in order to minimise the predicted toxicity in this age group. Adjuvant “induction” chemotherapy commenced at 4 weeks of age and consisted of four cycles of vincristine, adriamycin and cyclophosphamide at 50%, 75%, 75% and 100% of recommended doses (vincristine 0.05 mg/kg, adriamycin 0.83 mg/kg daily × 2, cyclophosphamide 40 mg/kg) at 3-weekly intervals. This was followed by four cycles of “maintenance” chemotherapy with vincristine (0.025 mg/kg), actinomycin (0.025 mg/kg) and cyclophosphamide (36 mg/kg) at full recommended doses. Cardioxane at a dose of 16.6 mg/kg was infused immediately prior to the adriamycin. Our patient is thriving at 19 months out from end of treatment.

Are fathers underused advocates for breastfeeding?

Fathers' knowledge base and attitudes influence breastfeeding practice. We aimed to evaluate if Irish fathers felt included in the breastfeeding education and decision process. 67 fathers completed questionnaires, which assessed their role in the decision to breastfeed, knowledge regarding the benefits of breastfeeding and attitude towards breastfeeding.Forty-two (62.7%) of their partners were breastfeeding. Antenatal classes were attended by 38 (56.7%); 59 (88.1%) discussed breastfeeding with their partners and 26 (38.8%) felt that the decision was made together. Twelve (48%) fathers of formula fed infants were unaware that breastfeeding was healthier for the baby. Most fathers (80.6%) felt that breastfeeding was the mother's decision and most (82.1%) felt that antenatal information was aimed at mothers only. Irish fathers remain relatively uninformed regarding the benefits of breastfeeding. This may contribute to their exclusion from the decision to breastfeed. Antenatal education should incorporate fathers more, and this may result in an improvement in our breastfeeding rates.

A disappearing neonatal skin lesion

A preterm baby girl was noted at birth to have a firm, raised, non-tender skin lesion located over her right hip. She developed three similar smaller lesions on her ear, buttock and right knee. All lesions had resolved by 2 months of age.

Life and death decisions for incompetent patients: determining best interests--the Irish perspective

AIMS

To determine whether healthcare providers apply the best interest principle equally to different resuscitation decisions.

METHODS

An anonymous questionnaire was distributed to consultants, trainees in neonatology, paediatrics, obstetrics and 4th medical students. It examined resuscitation scenarios of critically ill patients all needing immediate resuscitation. Outcomes were described including survival and potential long-term sequelae. Respondents were asked whether they would intubate, whether resuscitation was in the patients best interest, would they accept surrogate refusal to initiate resuscitation and in what order they would resuscitate.

RESULTS

The response rate was 74%. The majority would wish resuscitation for all except the 80-year-old. It was in the best interest of the 2-month-old and the 7-year-old to be resuscitated compared to the remaining scenarios (p value <0.05 for each comparison). Approximately one quarter who believed it was in a patient best interests to be resuscitated would nonetheless accept the family refusing resuscitation. Medical students were statistically more likely to advocate resuscitation in each category.

CONCLUSION

These results suggest resuscitation is not solely related to survival or long-term outcome and the best interest principle is applied differently, more so at the beginning of life.

The Neopuff's PEEP valve is flow sensitive

AIM

The current recommendation in setting up the Neopuff is to use a gas flow of 5-15 L/min. We investigated if the sensitivity of the positive end expiratory pressure (PEEP) valve varies at different flow rates within this range.

METHODS

Five Neopuffs were set up to provide a PEEP of 5 cm H(2) O. The number of clockwise revolutions to complete occlusion of the PEEP valve and the mean and range of pressures at each quarter clockwise revolution were recorded at gas flow rates between 5 and 15 L/min.

RESULTS

  At 5, 10 and 15 L/min, 0.5, 1.7 and 3.4 full clockwise rotations were required to completely occlude the PEEP valve, and pressures rose from 5 to 11.4, 18.4 and 21.5 cm H(2) O, respectively. At a flow rate of 5 L/min, half a rotation of the PEEP dial resulted in a rise in PEEP from 5 to 11.4cm H(2) O. At 10 L/min, half a rotation resulted in a rise from 5 to 7.7cm H(2) O, and at 15 L/min PEEP rose from 5 to 6.8cm H(2) O.

CONCLUSION

Users of the Neopuff should be aware that the PEEP valve is more sensitive at lower flow rates and that half a rotation of the dial at 5 L/min gas flow can more than double the PEEP.

Is hospital based MMR vaccination for children with egg allergy here to stay?

Egg allergy is incorrectly considered to constitute a contraindication to MMR in the community, despite a long history of its safe administration to egg allergic children. The product insert perpetuates this misinformation but the Irish guidelines from the RCPI are unequivocal. We reviewed all paediatric cases vaccinated in our hospital in 2007-2008. Forty seven of 91 children receiving vaccinations in hospital, had been referred for MMR due to concerns regarding egg allergy. In 32% (n=15), GP referral for vaccination was made despite correspondence from the clinic advising routine vaccination in the community. Nineteen were second MMR immunisations, which should all have occurred in the community. Unnecessary hospital referral for MMR vaccination is an extra burden on hospital resources, and causes unwarranted anxiety amongst parents of children with egg allergy. A change in practice seems difficult to achieve, as many referrals happen despite individualised correspondence to GPs and other referring clinicians outlining the current guidelines.

Potential hazard of the Neopuff T-piece resuscitator in the absence of flow limitation

OBJECTIVE

(1) To assess peak inspiratory pressure (PIP), positive end expiratory pressure (PEEP) and maximum pressure relief (P(max)) at different rates of gas flow, when the Neopuff had been set to function at 5 l/min. (2) To assess maximum PIP and PEEP at a flow rate of 10 l/min with a simulated air leak of 50%.

DESIGN

5 Neopuffs were set to a PIP of 20, PEEP of 5 and P(max) of 30 cm H(2)O at a gas flow of 5 l/min. PIP, PEEP and P(max) were recorded at flow rates of 10, 15 l/min and maximum flow. Maximum achievable pressures at 10 l/min gas flow, with a 50% air leak, were measured.

RESULTS

At gas flow of 15 l/min, mean PEEP increased to 20 (95% CI 20 to 21), PIP to 28 (95% CI 28 to 29) and the P(max) to 40 cm H(2)O (95% CI 38 to 42). At maximum flow (85 l/min) a PEEP of 71 (95% CI 51 to 91) and PIP of 92 cm H(2)O (95% CI 69 to 115) were generated. At 10 l/min flow, with an air leak of 50%, the maximum PEEP and PIP were 21 (95% CI 19 to 23) and 69 cm H(2)O (95% CI 66 to 71).

CONCLUSIONS

The maximum pressure relief valve is overridden by increasing the rate of gas flow and potentially harmful PIP and PEEP can be generated. Even in the presence of a 50% gas leak, more than adequate pressures can be provided at 10 l/min gas flow. We recommend the limitation of gas flow to a rate of 10 l/min as an added safety mechanism for this device.