Pediatric emergency medicine trisk 2471 2471
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allowing systemic venous blood to bypass the lungs (right-to-left shunt), but
central cyanosis may also be caused by respiratory compromise or pharmacologic
agents. Acrocyanosis, the transient blue discoloration of the hands and feet in
response to vasomotor instability or a cool environment, is caused by
vasoconstriction of the small arterioles and does not reflect reduced systemic
arterial oxygenation. Mottling is the patchy-colored appearance of the body
surface, resulting from dilation of the superficial veins showing through the thin
neonatal skin.
Goals of Treatment. The goals of ED evaluation of the cyanotic infant include
early recognition of cardiorespiratory pathology or pharmacologic causes.
Clinical Considerations
Clinical Recognition. Proper lighting is important to assess cyanosis in neonates.
Location of cyanosis helps determine its cause. Cyanosis noted in the mucous
membranes, tongue, trunk, and extremities is central. In contrast, acrocyanosis is
limited to hands, feet, and perioral region, with the tongue and rest of skin
remaining pink. This condition may be associated with cool ambient temperature.
Acrocyanosis is benign and may resolve with warming. Local blue discoloration
of a single extremity could be the result of compromised distal circulation. A
local blue hue to skin may also be the result of pigment from blue clothing dye.
Triage Consideration . “Blue babies” should be evaluated promptly for
cardiorespiratory disease. The degree of oxygen desaturation associated with
cyanosis should be documented by pulse oximetry.
Clinical Assessment. When obtaining history, relevant questions include the
following: When was the color change first noted? Is it persistent or intermittent?
For example, choanal atresia will cause cyanosis at rest, which improves with
crying, whereas the cyanosis of congenital cardiac disease will often worsen with
crying because of increased pulmonary vascular resistance. Does the cyanosis
improve with oxygen? Are there other accompanying symptoms? In cyanotic
cardiac disease (i.e., right-to-left shunt), the breath sounds will be normal with
symmetric chest excursion. In contrast an infant with cyanosis due to pulmonary
disease or congestive heart failure will have wheezes or crackles and accessory
chest muscle use. With pulmonary disease or congestive heart failure, the increase
in saturation may be dramatic when the infant receives increased oxygen (see
hyperoxia test, under Section: Neonatal Cardiac Emergencies).
