Pediatrics Answers 435tachycardia (SVT).SVT is the most common pathologic arrhythmia of
childhood.It is sometimes confused with sinus tachycardia, which usually
presents at a rate of < 225 beats per minute in infants and < 150 beats per
minute in older children and adults. This finding coupled with variability
with respirations and evidence of normal P waves will prove to be useful in
differentiating sinus tachycardia from SVT. This dysrhythmia is typically
well tolerated in young children and infants. SVT will often present with a
history of pallor, poor feeding, tachypnea, and lethargy, or irritability. Older
children will describe palpitations, lightheadedness, and shortness of
breath. Signs of congestive heart failure or shock may be present. SVT can
occur in children with no structural lesions and is associated with fever,
infection, or sympathomimetic drugs (such as cold medicine or bron-
chodilators), but is most often idiopathic. Stability is the most important
factor in managing patients with SVT. Stable patients usually have normal
mental status and only mild symptoms. Unstable patients typically present
in congestive heart failure or shock. Adenosineis safe and effective and has
a short half-life. It is the first-line therapy in patients with stable SVT. It
must be administered rapidly through a large-bore IV in a vein as close to
the heart as possible (antecubital is classic and generally adequate) and fol-
lowed by a 10- to 20-mL normal saline bolus using the double stopcock
method to flush it quickly. Adenosine will block conduction at the atri-
oventricular (AV) node leading to a brief period of asystole, which can be
very disconcerting to those receiving or administering the medication.
Synchronized cardioversion (a)is the treatment for any unstable
patient or when other treatment options failed. Carotid massage (e)is not
recommended in children owing to the concerns of dislodging plaques or
causing an intimal tear. Verapamil (b)should be avoided in infants since
it can cause potentially lethal hypotension. Defibrillation (c)is the treat-
ment for patients in ventricular fibrillation or pulseless ventricular
tachycardia.
395.The answer is a.(Fleischer and Ludwig, pp 1679-1680.)This is a case of
paraphimosis. Paraphimosis is a true emergency. It occurs when the
foreskin of an uncircumcised male is retracted beyond the glans and not
returned to its normal position.Ensuing congestion and edema make it dif-
ficult for it to be retracted back to its normal position. Manual reductionis
the first-line treatment for paraphimosis. Manual reduction is performed by
placing your thumbs over the glans as you attempt to gently pull the engorged
foreskin tissue back over the head of the penis. Ice can be applied to the penis