Perioperative Management of Extreme Hypotension in Autonomic Neuropathy
Jonathan E. Barry, MD and R. Victor Zhang, MD,
PhD
Department of Anesthesiology, University of Florida
Introduction. Autonomic neuropathy is a form of peripheral
neuropathy affecting the autonomic portion of the peripheral
nervous system. Although it is most commonly seen in patients
with diabetes mellitus, there are many other causes including
uremia in end stage renal disease (ESRD). Autonomic neuropathy
is a group of symptoms involving many organ systems. The
impairment of the cardiovascular system with orthostatic
hypotension presents an increased risk for general anesthesia.
In this report, we present a rare case of autonomic neuropathy
in a patient with ESRD and chronic hypotension who successfully
underwent general anesthesia for an arterio-venous (A-V) fistula
repair.
Clinical Course. A 42-year-old man was scheduled for an A-V
fistula revision. His past medical history was significant for
Alport’s syndrome, porphyria cutanea tarda, chronic pancreatitis,
peripheral neuropathy, ESRD, and autonomic neuropathy. His
history of ESRD included three failed renal transplants, and a
total of seventeen surgical procedures for hemodialysis (HD)
access. He had been HD-dependent for thirty years. Over the last
year, the patient became increasingly symptomatic with
orthostatic hypotension and hypotension in the supine position.
Management included keeping the patient’s intravascular volume
full during HD, and multiple medications to increase the blood
pressure towards the normal range. However, in the absence of
adequate HD, all theses measures were unsuccessful.
His vital signs in the preoperative clinic were: weight of 67
kg, blood pressure of 58/32 mmHg, heart rate of 81 beats/min,
and respiratory rate of 22 breaths/min. His preoperative
laboratory findings were Na 140 mEq/L, K 4.8 mEq/L, BUN 55
mg/dl, and Cr 10.5 mg/dl. His most recent echocardiogram
demonstrated an ejection fraction of 55-60% and moderate apical
and anterior septal wall hypokinesis. On the day of surgery the
patient was complaining of dizziness, lightheadedness, and
malaise with low blood pressure. He was given a 400 ml bolus of
0.9% NaCl. This increased his blood pressure to 61/41 mmHg, and
made him feel much better. The decision was made to place an
arterial line awake and proceed with the case.
A femoral arterial line was placed under ultrasound guidance. An
intravenous bolus of phenylephrine was given to verify its
ability to raise the arterial blood pressure. General anesthesia
with endotracheal intubation was induced by intravenous
etomidate and atracurium. An uneventful intraoperative course
was maintained with oxygen, nitrous oxide and isoflurane, with a
phenylephrine infusion to maintain an adequate blood pressure.
The patient was extubated at the end of the surgery and
discharged home on postoperative day two. Following the surgery,
his HD became adequate, and his blood pressure gradually
increased towards the normal range.
Discussion. Autonomic neuropathy with extreme hypotension offers
a unique challenge to anesthesiologists. Surgeries requiring
general anesthesia for patients with such clinical conditions
are likely canceled to avoid possible cardiovascular arrest.
However, autonomic neuropathy in uremia, which is likely caused
by an accumulation of toxic metabolites, is often improved with
adequate HD. This case report presents a clinical dilemma that
requires careful considerations before making a sound clinical
decision. This unique clinical scenario has not been previously
described.
