Zebras of Neonatal Hypoglycemia 06.09.2014

Morning ReportJune 2014Johanna Viau

Direct admit… PCP call 6 day old with hiccup like movements

and concerns for low sugars. Looks well now, feeding well, no fevers.

Birth History Pregnancy:

Late prenatal care, labs reassuring Delivery:

GBS positive, adequately treated NSVD, no complications BW: 3.3kg (AGA @ 39 wks)

Nursery course: Feeding: breast + formula supplementation Mild jaundice, Bili on DOL 2 < LL Discharged on DOL 2

DOL 3: PCP’s office Mom’s questions: hiccups on L side Feeding well, every 2 hours (breast + formula) Physical exam:

Wt: 3.15kg (95% birth weight) Normal vital signs and physical exam L side twitching x 20 sec, not suppressible

Bedside labs: Bili 12, glucose 38 Fed immediately, Sent to OSH for workup/tx via

EMS

DOL 3-5: OSH Admitted for workup/treatment Workup…. Normal per report Discharged on DOL 5

No clear diagnosis Glucoses in the 30-50’s range, better

after feeding Required IVF but feeding well on

discharge day Follow up w PCP the next day for a

glucose check

DOL 6: PCP office Chief complaint: hiccup like movements

last night, similar to the ones before you sent us to the hospital

Wt: 3.3kg (100% of BW, 58th %ile) Lt: 47cm (18th %ile) OFC 34cm (20th %ile) Vital Signs and physical exam: normal Feeding well Sent to PCH as direct admit

Admit Res pager:The direct admit has arrived Vital signs: T 36.5. HR 120x. RR 40x. BP

90/72. Sats 93% 30 second physical exam:

No acute distress, well hydrated No dysmorphic features Heart and lungs: normal Abd: Soft, without hepatosplenomegaly Neuro: somnolent, responding to

touch. +moro, +rooting, +suck. Moving all extremities equally and symmetrically.

Bedside glucose: 17 mg/dL

Differential diagnosisNEWBORN- LGA (hyperinsulinism)- SGA (no stores)- Prematurity- Infant of diabetic

mother

GASTRO/NUT- Poor feeding- Diarrhea- Vomiting- Malabsorption

ID- Sepsis- Meningitis- NEC- UTI

NEURO- Seizures- Asphyxia (depletion of

glycogen)- Midline

malformations(pituitary)

METAB/GENETICS- Inborn errors- Beckwith-Wiedemann- Hyperinsulinism- Adrenal insufficiency- Hypothyrodism- Hypopituitarism

OTHER- Maternal meds:

terbutaline, sulfonylureas

- Drugs- Toxins- Tumor- Muchausen

Outside hospital Workup Septic Workup:

CBC: WBC 8.2. HGB 21. PLT 140

CSF: WBC 4. RBC 222. Glu 14. Prot 84

UA: normal Blood, Urine &

CSF: negative @ 48h

Glucoses: 30-50’s

Neuro Workup: Head CT: normal EEG: mild

generalized cerebral dysfunction which could be due to medications, post-ictal state, metabolic or underlying structural

Started on phenobarbital

Critical Labs results CMP: Na 143, K 5.2, Cl 107, CO2 22, AG 14, glucose

22, BUN 4, Cr 0.57, Ca 10.3, protein 6.0, albumin 3.4, bili 9.2, alk phos 209, ALT 14, AST 36

Cortisol 6.5 (1-22) Insulin 10.6 (6.0-27.0) Beta-hydroxybutyrate 0.2 (0.0-0.6) Lactic Acid 3.8 (0.5-2.2) Ammonia 50 (56-92) Growth Hormone 7.84 (0.1-6.2) Urine ketones negative Reducing substances negative carnitine free 15 (15-55); total 19 (21-83 free fatty acids 0.49 (0.43-1.37)

The zebras of Neonatal HypoglycemiaAka: “something metabolic”

Glucose homeostasis in the newborn

Pregnancy

0 – 8-12 hours

> 12 hours

Passive diffusion of glucose Fetal plasma glucose = 70-80% of

maternal Insulin doesn’t cross the placenta

Fetus produces his own insulin

Birth clamping of umbilical cord Stress hormones: catecholamines,

glucagon, cortisol, growth hormone Insulin secretion

Pregnancy

0 – 8-12 hours > 12 hours

Glucose > 40 mg/dL (controversial) Feeds: ± Glucose depends on GLUCOGENOLYSIS

Adequate stores (glycogenesis) Prematurity, SGA, IUGR, etc. GSD 0

Enzymes for glucogenolysis GSD 1 GSD 3

Pregnancy 0 – 8-12 hours

> 12 hours

KetonesLactateHepatomegaly ?

Glucose > 50mg/dL (controversial) Glycogen stores depleted Glucose depends on

Feeds Galactose intolerance

Gluconeogenesis Amino acids metabolism Fatty acid metabolism

Pregnancy 0 – 8-12h > 12 hours

KetonesAcidosisAmmonia

Lactic acidKetonesAmmonia

Critical Labs results Cortisol 6.5 (1-22) Insulin 10.6 (6.0-27.0) Growth Hormone 7.84 (0.1-6.2) Ketones, Beta-hydroxybutyrate: negative Lactic Acid 3.8 (0.5-2.2) Ammonia 50 (56-92) Reducing substances negative carnitine free 15 (15-55); total 19 (21-83 free fatty acids 0.49 (0.43-1.37)

Congenital Hyperinsulinism

#1 cause of persistent hypoglycemia Several diseases High insulin despite hypoglycemia

Increased glucose utilization Even if feeds are going well

High GIR’s needed Multiple mutations Channelopathies Islet cell hyperplasia Focal vs diffuse Transient vs permanent

Treatment Supportive Diasoxide Pancreatectomy

Take home points: No obvious perinatal risk factors

gestational diabetes, perinatal asphyxia, infections, prematurity, SGA, LGA

Dysmorphic features Severe hypoglycemia

GIR > 8-10mg/kg/min Glucose Infusion Rate calculator

http://www-users.med.cornell.edu/~spon/picu/calc/glucinfr.htm Persistent hypoglycemia

Despite feeds or more than a few hours after birth

When to consider the zebras

Take home points:Overview of the zebrasPregnancy/

Birth 4-12 hours > 12 hours

The “horses” or associated to perinatal risk factors

Glycogen storesGlycogenesisGlycogenolysis

FeedsAmino acidsFatty acids

Low cortisol, low GH, high insulin

References See Wai Chan. Neonatal Hypoglycemia.

UptoDate. Sperling, Mark. Differential diagnosis

and management of Neonatal Hypoglycemia. Pediatr Clin N Am 51 (2004) 703 – 723