Strongly consider treating any neonate with cyanosis secondary to suspected congenital heart disease with prostaglandin E1 (PGE1) at 0.05-0.1 microg/kg per minute to keep the ductus arteriosus patent. It is imperative to prepare for endotracheal intubation as PGE1 may cause apnea. Expert pediatric cardiology consultation should be sought early in the course, as echocardiography is essential for further diagnosis and management of the patient.

If a respiratory disorder is suspected, administer oxygen as outlined and treat the underlying disorder. Prepare for endotracheal intubation, as neonates can rapidly progress to respiratory arrest.

The treatment of choice for methemoglobinemia is methylene blue, which acts as an oxidizing agent that is reduced to leukomethylene blue, which in turn reduces methemoglobin to hemoglobin. Methylene blue is indicated if methemoglobin exceeds 25% or if the patient has clinical signs of hypoxia (e.g., lethargy, respiratory distress). In neonates, the dose is 0.3-1 mg/kg as a 1% solution, given intravenously over 3-5 minutes; effects usually are apparent within 30 minutes.

Finally, because sepsis frequently presents with cyanosis and shock in the neonate, a sepsis workup including blood, urine, and cerebrospinal fluid cultures should be obtained and intravenous antibiotics administered as soon as possible.

Of note, broad-spectrum antibiotics (e.g., vancomycin and cefotaxime) should be administered as soon as possible and should not be delayed pending lumbar puncture.

Summary

The evaluation of the cyanotic neonate should be done in an algorithmic manner that focuses on evaluation and management of the most life-threatening disease processes first.The hyperoxia test should be utilized early in the evaluation of these patients to assist in the differentiation and categorization of the cyanotic event. Be careful to obtain a detailed history of the prenatal, birth, and postnatal periods, as physicians will often be able to narrow the differential by the history alone. Neonates may decompensate very quickly, and preparations for a life-saving emergency using the PALS and NRP/NALS guidelines should be made as soon as possible.

Resources

• Avarello JT. Cardiac emergencies. In: Neonatal Emergencies. New York: McGraw-Hill Medical; 2009.
• Bernstein D. Acyanotic congenital heart disease: The left-to-right shunt lesions. In: Nelson’s Textbook of Pediatrics. 18th ed. Philadelphia: Saunders; 2003.
• Bernstein D. Cyanotic congenital heart disease: Evaluation of the critically ill neonate with cyanosis and respiratory distress. In: Nelson’s Textbook of Pediatrics. 18th ed. Philadelphia: Saunders; 2003.
• DeBaun M, Vichinsky E. Hemoglobinopathies. In: Nelson’s Textbook of Pediatrics. 18th ed. Philadelphia: Saunders; 2003.
• Marino BS, Bird GL, Wernovsky G. Diagnosis and management of the newborn with suspected congenital heart disease. Clin Perinatol. 2001;28(1):91-136.
• Steinhorn R. Evaluation and management of the cyanotic neonate. Clin Ped Emerg Med. 2008;9:169-175.