II. Precautions
- Cyanosis is related to the absolute Hemoglobin concentration (not the oxygenated-deoxygenated ratio)
- Conditions in which Cyanosis manifests at higher Oxygen Saturations (early sign)
- Increased Hemoglobin (e.g. Polycythemia Vera, most newborns)
- Conditions in which Cyanosis manifests at lower Oxygen Saturations (delayed sign)
- Anemia
- Increased fetal Hemoglobin ratio to adult Hemoglobin
III. Causes: Transient Cyanosis after Delivery
-
Central Cyanosis
- Central Cyanosis is a concerning sign outside the first few minutes of life
- Central Cyanosis should clear in minutes of birth
- Tongue and Mucus membranes are pink initially in normal newborns
- Acrocyanosis (Peripheral Cyanosis)
- Bluish-gray distal extremities
- Results from slow flow in the peripheral capillary beds
- Does not correlate with PaO2
- Clears within 1-2 days
IV. Causes: Cyanotic Cardiac Defect
- See Congenital Heart Disease
- Transposition of the Great Vessels
- Total Anomalous Pulmonary Venous Return
- Ebstein's Anomaly
- Tricuspid Atresia
- Pulmonary Atresia with Intact Ventricular Septum
- Severe Pulmonary Stenosis
- Severe Tetralogy of Fallot
- Associated Congestive Heart Failure Causes
V. Causes: Lung Disorders
- Transient Tachypnea of the Newborn
- Respiratory Distress Syndrome
- Aspiration
- Meconium Aspiration
- Blood or amniotic fluid aspiration
- Pneumonia
- Pneumothorax
- Pleural Effusion
- Congenital Diaphragmatic Hernia
- Persistent Pulmonary Hypertension
VI. Causes: Airway Disorders
- Choanal Atresia
- Pierre-Robin Syndrome
- Macroglossia
- Vascular Ring or Pulmonary Sling
- Neck Mass (e.g. Cystic Hygroma)
VII. Causes: Miscellaneous
- Apnea or asphyxia
- Hemorrhage
- Seizure
- Hypothermia
- Electrolyte abnormality
VIII. Causes: Cyanosis with normal pO2
- Methemoglobinemia (decreased and refractory Oxygen Saturation)
- Polycythemia
- Vasoconstriction (e.g. Cold environment)
IX. Diagnostics
- Chest XRay
- Electrocardiogram
- Hematocrit
-
Arterial Blood Gas on 100% oxygen
- Arterial pO2>200 rules out Congenital Heart Disease
- Simultaneous Pre-Ductal, Post-Ductal Arterial Blood Gas
- Indications
- No obvious pulmonary cause
- Persistent pO2 <100 mmHg
- Interpretation: No difference in pre and post pO2
- Suggests right to left shunt via ductus arteriosus
- Causes
- Persistent Pulmonary Hypertension
- Critical Aortic Coarctation
- Interrupted Aortic Arch
- Indications
X. Management
- Follow initial protocol per Neonatal Resuscitation
-
Congenital Heart Disease Management
- Consider Prostaglandin E1
- Manage associated CHF
XI. References
- Joseph and Webb (2015) Crit Dec Emerg Med 29(1): 10-8
- Cloherty (1991) Neonatal Care, Little Brown, p. 261-70
- Fuloria (2002) Am Fam Physician 65(1):61-8 [PubMed]