Lithotripsy

Question 1

What is extracorporeal shock wave lithotripsy

(ESWL)?

Answer 1

ESWL is a method of breaking up renal calculi by using highenergy
shock waves to fracture the stone.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 752.

Question 2

Why is control of patient movement important during

lithotripsy?

Answer 2

Shock waves from the lithotriptor are aimed at the stone itself.
If the patient moves, the stone moves out of the shockwave’s
path and other structures move into it. Even irregular breathing
can affect the efficacy of the treatment.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 754.

Question 3

Which method of anesthesia is preferred for

immersion lithotripsy and why?

Answer 3

General anesthesia is often preferred because of the rapid
onset and control of patient movement.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 754.

Question 4

How do modern lithotriptors work?

Answer 4

Lithotriptors use water bags containing water, oil, or a highacoustic
fluid that are pressed against the patients body to
minimize any air in the interface. The shock waves are passed
through the patients body to break up small kidney stones.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 752-753.

Question 5

What are the most common dysrhythmias seen

during lithotripsy?

Answer 5

Supraventricular premature complexes and premature
ventricular complexes are the most common dysrhythmias seen
during lithotripsy.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 754.

Question 6

Why is the quality of the ECG recording during

lithotripsy so important?

Answer 6

The lithotripsy shock waves are timed with the R wave on the
ECG to reduce the incidence of mechanical disruption of the
cardiac rhythm and development of potential dangerous
arrhythmias.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 754.

Question 7

What types of anesthesia are suitable for lithotripsy?

Answer 7

A variety of anesthetic techniques have been used for ESWL
including spinal anesthesia, monitored anesthesia, and
continuous infusions of propofol, ketamine, methohexital, or
alfentanil with or without midazolam.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 754.

Question 8

When performing spinal or epidural anesthesia for
lithotripsy, what dermatome level of anesthesia is
required?

Answer 8

A T4 to T6 level is required for effective analgesia.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 754.

Question 9

What are the contraindications to performing

lithotripsy?

Answer 9

Pregnancy and untreated bleeding disorders are the only
absolute contraindications to lithotripsy. Pacemakers,
abdominal aortic aneurysms, orthopedic prosthetic devices, and
obesity are no longer considered contraindications. AICD and
lithotripter manufacturing companies generally state that AICDs
are a contraindication to lithotripsy, but patients with AICDs
have been shown to complete the procedure successfully.
Older abdominally-implanted AICDs present a greater hazard
than transvenous pacemakers. The AICD should be shut off
prior to treatment and then reactivated immediately after the
procedure.
Miller RD. Miller’s Anesthesia. 8th ed. Philadelphia: Elsevier
Saunders; 2015: 2237