Notes from Urology Textbook

14. Treatment
• Mild Allergic-Like and Physiologic
Reactions.
– Observation and reassurance are often all
that is needed.
– Usually, no intervention or medication is
required.
– If needed, an H1-receptor blocker such as
diphenhydramine (Benadryl) PO/IM/IV 1
to 2 mg/kg up to 50 mg may be helpful in
this patient population.
– Caution is advised: these reactions may
progress into a more severe category.
– Consequently these patients should be
observed for 20 to 30 minutes.
– If necessary:
• Administer:
– chlorpheniramine 4 to 10 mg orally,
intravenously, or intramuscularly,
– + diazepam 5 mg for anxiety.
– For bronchospasm, oxygen 6 to 10 L/min should
be administered,
– + a β-agonist inhaler used at 2 puffs (90
mcg/puff) for a total of 180 mcg; this can be
repeated up to three times.

15. Moderate Allergic-Like and
Physiologic Reactions.
– Moderate ARs occur in 0.5% to
2% of patients and require
treatment but are not
immediately life threatening.
– These reactions are usually
transient and require treatment
with close observation, using:
• hydrocortisone 100 to 500 mg
IM or IV,
• or β-agonist inhalation for
bronchospasm bronchiolar
dilators (metaproterenol
[Alupent], terbutaline
[Brethaire], or albuterol
[Proventil or Ventolin]) 2 to 3
puffs; repeat as necessary.
• For bronchospasm, oxygen 6 to
10 L/ min should be administered
and a β-agonist inhaler used at 2
puffs (90 mcg/puff) for a total of
180 mcg; this can be repeated up
to three times.
• Epinephrine can be added to
moderate or severe
bronchospasm (see the following
for epinephrine dosing).
• Severe Allergic-Like and Physiologic
Reactions.
– Life-threatening reactions occur in approximately 1/1000 uses for
high osmolar agents and are far less frequent for LOCM, with both
types of agents resulting in mortality rates of 1/170,000 uses.
– Immediate treatment is required and the patient usually requires
emergency care, involving particular attention to the respiratory and
cardiovascular systems.
– If bronchospasm is severe and not responsive to inhalers, or if an
upper airway edema (including laryngospasm) is present,
epinephrine should be used promptly.
– Rapid administration of epinephrine is the treatment of choice for
severe contrast reactions. Epinephrine is administered IV : dose of
0.1 mL/ kg of 1:10,000 dilution or (0.01 mg/kg) slowly into a
running IV infusion of saline and can be repeated every 5 to 15
minutes as needed. The maximum single dose is 1.0 mL (0.1 mg)
and can be repeated as needed to a total dose of 1 mg.
– If no IV access is available, the recommended intramuscular dose
of epinephrine is 0.01 mg/kg of 1:1000 dilution (0.01 mL/ kg) to a
maximum of 0.15 mg of 1:1000 if less than 30 kg (0.3 mg if weight
is >30 kg) is injected intramuscularly in the lateral thigh. This can be
repeated every 5 to 15 minutes up to 1 mL (1 mg) total dose.
– Epinephrine must be administered with care to patients who have
cardiac disease or those who are taking beta-blockers because the
unopposed alpha effects of epinephrine in these patients may cause
severe hypertension or angina.
• Antihistamines don’t have major role in the treatment of severe reactions.
• Careful monitoring of patient vital signs is paramount.
• Both hypotension & tachycardia indicates likely anaphylactic reaction.
• Bradycardia is a sign of vasovagal reaction and therefore the use of beta-
blockers is to be avoided.
• Hypotension resulting from an anaphylactic reaction can be treated with
intravenous iso-osmolar fluids (e.g., 0.9% normal saline or Ringer’s lactate
solution): several liters of fluid may be needed before obtaining a
significant hemodynamic response.
• If fluid and oxygen are unsuccessful in reversing the patient’s hypotension,
the use of vasopressors is indicated. The most effective vasopressor is
dopamine. Dopamine should be used at infusion rates between 2 and 10
mcg/kg/min.