Blue Spells in “Well Babies”

1. Blue Spells in “Well Babies” N. Ambalavanan MD Assistant Professor, Division of Neonatology University of Alabama at Birmingham Aug 2005

2. What are “blue spells”? • Sudden onset of: • Central cyanosis • with respiratory distress • without distress • Apnea and / or Limpness • with cyanosis • without cyanosis • Choking

3. What is normal in well babies? • Transient central cyanosis during crying or straining, resolving rapidly when the baby is quiet • Periodic breathing, with pauses of up to 15 seconds, with no cyanosis or bradycardia • Occasional GE reflux (“spitting up”) • Bradycardia on deep pharyngeal suctioning • Acrocyanosis and/ or dark lips (with pink tongue) • Changes in tone with sleep state

4. Central cyanosis in neonates • Oxygen saturation of <85% may present as central cyanosis, if deoxygenated Hb> 4-5g / dL • Not all hypoxemia presents as cyanosis: • PaO2 is in the 35-50 mm Hg range (SpO2 85-90%) • Hb too low (e.g. Hb 10, 80% SpO2) • Not all cyanosis due to hypoxemia • methemoglobinemia • Focus: Pulmonary or non-pulmonary etiology?

5. Cyanosis: Pulmonary or non-pulmonary? • Tachypnea and/or increased depth of breathing may be seen with both pulmonary and non-pulmonary causes • Retractions are more often seen with lung disease • Slow breathing may be seen with non-pulmonary causes (esp. CNS causes)

6. Pulmonary causes of cyanosis • Most common: • Parenchymal lung disease most common • TTN • RDS • pneumonia • meconium aspiration • malformations (CCAM, CLE etc) • Rare causes • CDH, spontaneous pneumothorax, airway obstruction (e.g. Pierre-Robin syndrome, laryngeal web, vascular rings and slings)

7. Non-pulmonary cyanosis + Rapid breathing • Cardiac abnormality • eg. TGA, TOF, TAPVR, Truncus A, Tricuspid Atr, AV Canal, HLH • mixing lesions / decreased PBF / decreased CO • Persistent pulmonary hypertension (PPHN) • Septicemia • Metabolic and blood disorders • hypoglycemia / CAH / hypothermia / Inborn error of metabolism / Methemoglobinemia • Early shock

8. Non-pulmonary cyanosis + slow breathing • CNS • Sedation due to maternal or neonatal drugs (MgSO4, opiates) • Meningitis • Perinatal asphyxia • CNS trauma due to difficult delivery • CNS malformation • Congenital neuromuscular disease (e.g. congenital myotonia, myasthenia)

9. Inborn errors of metabolism (IEMs) • IEMs may present • before birth, at birth, during first 2-3 days, • as sudden death (or) as deterioration following normal birth and delivery • Mom may develop HELLP if fetus has LCHAD deficiency • Perinatal asphyxia common misdiagnosis (esp if congenital lactic acidoses or pyridoxine dependency) • Sudden death may occur with fatty acid oxidation defects [Leonard & Morris: Lancet 2000; 356: 583-87]

10. Inborn errors of metabolism (IEMs) • Seizures/Apnea • Pyridoxine dependency • Peroxisomal disorders • Molybdenum cofactor deficiency • Non-ketotic hyperglycinemia • Congenital lactic acidosis • Severe hypotonia • Peroxisomal disorders • Non-ketotic hyperglycinemia • Congenital lactic acidoses • Carbohydrate deficient glycoprotein syndromes

11. Inborn errors of metabolism (IEMs) • Cardiomyopathy and arrhythmias may occur with LCFA oxidation or respiratory chain defects • Neurologic deterioration may occur with organic acidemias, urea-cycle defects, MSUD, FAO defects, congenital lactic acidoses etc • Persistent metabolic acidosis with normal tissue perfusion may occur with organic acidemia or congenital lactic acidosis • Mild respiratory alkalosis in non-ventilated babies may signify hyperammonemia, esp if irritability and stridor also present

12. Management • History • Exact details of episode, antecedent factors, and how episode resolved • Obstetric history - anesthesia, MgSO4, GBS, PROM, antibiotics, HSV • Delivery history - need for resuscitation, Apgar scores, medications used • Family history of similar spells, inborn errors of metabolism

13. Management • Physical examination • Cyanosis / Pallor / Perfusion / Temperature / O2 Saturation • Respiration - apnea / periodic / fast / slow • G / F / R / Stridor (r/o choanal atresia, laryngomalacia) • Heart rate - regular / arrhythmia • BP - four limb • Auscultation: S1 / S2 / Murmurs / Lung sounds • Abdominal organomegaly • CNS - Tone / Reflexes / Symmetry / AF / Abnormal movements

14. Management • Investigations to consider • Sepsis screen (CBC, BlCx, CSF, CXR) • Cardiac screen (ECHO, EKG, 100% O2 test, pre- and post-ductal SpO2) • CAH screen (Electrolytes) • MetHb screen (ABG for MetHb, blood exp to room air) • CNS screen (Cranial USG, CSF, EEG, CT/MRI) • IEM screen (at time of sepsis screen) • ABG (pH, HCO3), Glucose, Electrolytes, Anion Gap, LFTs, Ammonia, Pediatrix newborn screen, urine sugars and ketones

15. Management • Therapy • directed towards possible cause • general supportive neonatal intensive care important • Airway, Ventilation, Perfusion, IV access • O2 / mechanical ventilation if pulmonary disease • Antimicrobials if suspicion of sepsis / meningitis • PGE1 if suspicion of ductal dependent cardiac disease

16. Management of IEMs • Stop nutrient triggering disorder e.g. protein, galactose • Give high-energy intake • NICU care to correct tissue perfusion, dehydration, acidosis • Hyperammonemia Rx with Na benzoate, Na phenylbutyrate, arginine • Dialysis • Insulin to control hyperglycemia and reduce catabolism • Vitamins e.g Biotin, B6, B12 • Specific therapy e.g. carnitine, glycine

17. Home monitors? • Do not monitor for transient choking, reflux, apnea, bradycardia or cyanosis that was not life threatening • Do not monitor asymptomatic premies, all sibs of SIDS infants, infants of drug-using moms • Monitoring can be done if: • event truly life-threatening (required CPR or vigorous stimulation) with no identifiable cause or if untreatable cause (e.g severe CNS hypoventilation) • Sibling of two or more infants who died of SIDS • Monitors not an answer for most infants