Neonatal Hypoglycemia

NICU Night Team Curriculum 1

Objectives

• Define neonatal hypoglycemia • Know the causes of neonatal hypoglycemia • Know signs and symptoms of hypoglycemia • Understand treatment

Case

39 wk F born by NSVD to a 22 y/o G 1 P 0 mom with diet controlled GDM A 1 . Mom’s blood sugars throughout the pregnancy ranged from 120-160. Maternal serologies were negative, pregnancy otherwise unremarkable. APGARS were 8 and 9 at 1 and 5 minutes, respectively. BW was 4,000 g.

Physical Examination

VS: T 36.5 P 148 RR 80 BP 55/38 mmHg HC 34 cm (75%), Lt 50 cm (75%), BW 4,000 (>97%) GA: Well appearing F, NAD, no cyanosis HEENT: AF 2x2 cm, no cleft lip and palate Heart: RR, no murmur Lungs: Tachypneic breathing with even breath sounds throughout, no retractions, no flaring Abdomen: Soft ND, no hepatosplenomegaly Genitalia: Normal female genitalia Extremities: No deformities, MAEE

Labs

1 hour of life: Hematocrit 56% Dexi 30 mg% Serum glucose 34 mg%

What is your primary concern in this patient?

Neonatal Hypoglycemia Impaired glucose metabolism

Serum blood glucose < 40 mg/dL OR Point of Care testing (accucheck, Dexi) <45

Why was a Dexi checked in this patient?

She is at risk for developing hypoglycemia

Hypoglycemia

Definition: A plasma glucose of less than 40 mg/dl Plasma glucose is higher than whole blood glucose by 15%

Physiology

Fetal Glucose Metabolism

• Fetus does not produce glucose • Maternal glucose is the only source of fetal glucose • Baseline fetal blood glucose is 60-70% of maternal serum glucose

Physiology

Glucose metabolism after birth

Cessation of maternal glucose supply Blood glucose Nadir ( ~1-2 hrs after birth)

Glucose Metabolism After Birth

Cessation of maternal glucose supply Surge in glucagon, catecholamine Decrease insulin Gluconeogenesis: Hepatic glycogen, amino acid, fatty acid metabolism Normal blood glucose

Etiology of neonatal hypoglycemia

1. Increased utilization (e.g.: hyperinsulinism) 2. Decreased production/stores 3. Increased utilization and/or decreased production

Increased Utilization

• Diabetic mother • Large for gestational age (LGA) infant • Erythroblastosis • Islet cells hyperplasia • Beckwith-Wiedemann syndrome • Insulin producing tumors • Maternal tocolytic therapy with B-sympathomimetric agents • Malposition of umbilical artery catheter

Decreased Production/Stores

• Prematurity • Intrauterine growth retardation(IUGR) • Inadequate caloric intake • Delayed onset of feeding

Increased utilization AND Decreased production

• Perinatal stress eg. shock, sepsis, asphyxia • Enchange transfusion • Defect in carbohydrate metabolism eg. glycogen storage disease • Endocrne deficiency eg. adrenal insufficiency, hypopituitarism • Defect in amino acid metabolism • Polycythemia • Maternal therapy with B-blocker

When do you screen?

1. Symptoms that could be due to hypoglycemia.

2. At risk infants.

What are signs and symptoms of hypoglycemia?

Signs and Symptoms of Hypoglycemia

Symptoms are NON-SPECIFIC

• Jitteriness • Apnea • Irritability • Grunting • Lethargy • Seizures

Who is

at risk?

• Infants of diabetic mothers • Maternal use of B-adrenergic agonist/ antagonist • IUGR • LGA • Preterm • Polycythemia • Asphyxia • Sick infant

When is the ideal time to screen high risk infants?

Screening

Blood glucose or point of care testing (POC) should be done in high risk infants within the first 1 to 2 hours after birth

Back to our case:

1. Term LGA infant 2. IDM with poor blood glucose control 3. Tachypnea 4. Hypoglycemia

Why do you think she developed hypoglycemia?

Hyperinsulinism

Pathophysiology : infants of diabetic mothers

How do you treat this patient?

• Feeding?

• IV therapy?

• Medication?

Management – Oral Feeds

• Can be used in asymptomatic infants • Only formula (never administer glucose water!!) • Follow up blood glucose within 1 hour of feeding.

• If the glucose level doesn’t rise, a more aggressive therapy may be needed.

• • • •

Management – IV therapy

Indications: Inability to tolerate oral feeding Symptomatic infant Lack of response with oral feeds Glucose < 25 mg/dL, regardless of patient’s symptoms

Management – IV therapy

Urgent treatment • Bolus 2 ml/kg of D10W • Do not use 25% or 50% glucose !!

• Follow bolus with continuous dextrose fluid

Management – IV therapy

Continuing IV fluid • Start infusion of glucose at a rate of 6-8 mg/kg/min • Glucose infusion rate formula (GIR): GIR = %IV fluid x rate(ml/hr) 6 x BW(kg)

Management – IV therapy

• Re-check serum glucose 20-30 min after bolus and hourly until stable – If glucose is normal and stable, feeding may be continued and glucose infusion tapered – If glucose can’t be maintained > 50 mg/dL, increase GIR by 1-2 mg/kg/hr – If glucose can’t be maintained > 50 mg/dL, with a GIR 12 mg/kg/min, medication should be added.

Management – Medication

Persistent hypoglycemia despite a GIR > 12 mg/kg/min.

• Work up – Critical Labs: – Serum cortisol, insulin, growth hormone when glucose is low and prior to treatment – DO NOT wait >5 minutes for labs prior to treating hypoglycemia • Medication – Hydrocortisone – Glucagon – Diazoxide

Hydrocortisone

• Dose: 10 mg/kg/day IV q 12 hrs • Indication: Hypoglycemia despite GIR > 12 mg/kg/min • Send hormone level before starting hydrocortisone!!!

Glucagon

• Dose: 0.025-0.3 mg/kg IM/IV (maximum 1 mg) • Should cause recovery of hypoglycemia • May not work if – Reduced glycogen stores – Glycogen storage disease

Diazoxide

• Dose: 2-5 mg/kg/dose PO q 8 hrs.

• Indication: Infants who have persistent hyperinsulinemia (e.g.. Nesidioblastosis)

Back to our case:

How would you treat our patient?

Remember, he was tachypneic Urgent treatment:D10W 2 mL/kg IV bolus followed by continuous IV fluid

Board Question

A term infant was born to a pre-ecclamptic mother. BW was 2,000 g (<10 th %). Physical exam was normal. Blood glucose at 2 hour of age was 30 mg/dL What is your next step in management?

a. D10W bolus of 4 mL b. D10W continuous IV infusion at 6.5 ml/hr c. 20 mL of oral glucose water d. 20 mL of infant formula

Board Question

A term infant was born to a pre-ecclamptic mother. BW was 2,000 g (<10 th %). Physical exam was normal. Blood glucose at 2 hour of age was 30 mg/dL What is your next step management?

a. D10W bolus of 4 mL b. D10W continuous IV infusion at 6.5 ml/hr c. 20 mL of oral glucose water d.

20 mL of infant formula

Reference

• • • Wilker RE. Hypoglycemia and hyperglycemia. In: Cloherty JP, Eichenwald EC, Stark AR, eds. Manual of Neonatal care. 5 th ed. Lippincott Williams & Wilkins; Philadelphia; 2008: 540-549 Cornblath M, Ichord R. Hypoglycemia in the neonate. Semin Perinatol 2000;24:136-149 Sperling MA, Menon RK. Differential diagnosis and management of neonatal hypoglycemia. Pediatr Clin North Am 2004;51:703-723