0071643192.pdf

PEDIATRICS

Hypercyanotic spells (“tet spells”) are often associated with crying or feeding (thought

to be due to acute worsening of pulmonary outflow tract obstruction causing increased

R→L shunting). Maneuvers that increase systemic vascular resistance (such as squat-

ting) often help counteract this by decreasing the gradient for this R →L shunting.

DIAGNOSIS

■ CXR may show a “boot-shaped” heart.

■ Physical exam reveals a single loud S2 and a harsh systolic murmur (pul-

monic stenosis).

■ Echocardiogram reveals the anatomy.

TREATMENT

■ Acute cyanosis (tet spell): place patient in squatting or knee-to-chest position,

administer O 2 and morphine. Patients unresponsive to these measures

should receive IVF (to increase pulmonary blood flow), sodium bicarbonate

(to treat acidosis) and vasopressors (to increase SVR).

■ Definitive treatment is complete surgical repair.

■ Palliative shunts such as Blalock-Taussig (anastomosis of subclavian artery

to pulmonary artery) shunt are aimed at increasing pulmonary blood flow.

HYPOPLASTICLEFTHEART(HLH) SYNDROME

Hypoplasia of the left ventricle is associated with hypoplasia of the aorta; a

patent PDA is essential for systemic blood flow. As the PDA closes, infants pre-

sent with a shocklike state as blood flow to the systemic circulation is cut off.

TREATMENT

■ Initial management focuses on maneuvers to keep the PDA open––“relative

hypoxia” (avoidance of high FiO 2 ), prevention of acidosis, and prostaglandin

infusion.

■ Three-stage surgical repair: Norwood →Glenn→completion Fontan.

TRANSPOSITION OF THEGREATARTERIES(TGA)

Essentially, pulmonary and systemic system running in parallel with VSD,

ASD, or PDA allowing mixing of blood.

DIAGNOSIS

■ Auscultation reveals single S2 and no murmur.

■ CXR reveals “egg on a string” due to narrow upper mediastinum from

abnormally positioned great vessels.

■ Echocardiogram reveals the anatomy.

TREATMENT

■ Prostaglandin infusion to keep the PDA open until palliative atrial septo-

plasty (to create large ASD) can be performed)

■ Definitive surgical treatment with arterial or atrial level switch (Mustard or

Senning procedure)

TRUNCUSARTERIOSUS

Single arterial trunk from ventricles becomes aorta and pulmonary arteries.

VSD is always present. Pulmonary overcirculation can lead to CHF.

VENTRICULARSEPTALDEFECT(VSD)

A defect (hole) in the ventricular septum

First maneuver in treatment of

tet spell: Squating or knee-to-

chest position.

Boot-shaped heart on

CXR = TOF

Egg on a string-shaped heart

of CXR = TGA