Extra Topic 6.7 -- Arachnoiditis & Vancomycin Reaction

Question 1

The surgeon is requesting antibiotic prophylaxis.

Would you be ok with giving a cephalosporin antibiotic?

(You are seeing a 42-year-old female scheduled for umbilical hernia repair. She reports taking narcotics daily for chronic low back pain secondary to arachnoiditis. You also learn that she had a reaction to penicillin, during which she says, “it was hard to breathe”.)

Answer 1

While I understand that the true cross-reactivity between penicillin and cephalosporins is about 0.5% for first-generation cephalosporins and near zero for both second and third-generation cephalosporins, I would not administer a cephalosporin to a patient who had experienced anaphylaxis following penicillin administration due to the potentially serious consequences of this type of reaction.

Therefore, since this patient’s history of difficulty breathing is consistent with an anaphylactic response, I would suggest utilizing vancomycin rather than a cephalosporin for antibiotic prophylaxis.

Question 2

You decide to order vancomycin for antibiotic prophylaxis. The nurse calls to tell you that the patient is “very red” and his blood pressure has dropped. What do you think is going on?

(You are seeing a 42-year-old female scheduled for umbilical hernia repair. She reports taking narcotics daily for chronic low back pain secondary to arachnoiditis. You also learn that she had a reaction to penicillin, during which she says, “it was hard to breathe”.)

Answer 2

The timing of his hypotension, along with flushing (“very red”) and upper body erythema, is consistent with “red man’s syndrome”, which results when rapid administration of vancomycin leads to histamine release.

While the most common manifestation of rapid administration (10-15 mg/kg should be administered over 60 minutes) is isolated hypotension, other symptoms such as pruritis, flushing, upper body erythema, and even cardiac arrest may occur.

Giving antihistamines, such as diphenhydramine (H1-receptor antagonist) and cimetidine (H2-receptor antagonist), one hour before vancomycin administration may attenuate the drop in systemic vascular resistance associated with histamine release.

Question 3

What are the causes of arachnoiditis?

(You are seeing a 42-year-old female scheduled for umbilical hernia repair. She reports taking narcotics daily for chronic low back pain secondary to arachnoiditis. You also learn that she had a reaction to penicillin, during which she says, “it was hard to breathe”.)

Answer 3

There are several potential causes of arachnoiditis (inflammation of the meninges and subarachonid space), such as:

1. direct injury to the spine, as may occur with trauma, spinal surgery, and multiple lumbar punctures (especially when bleeding into the spinal fluid occurs);
2. infections, such as tuberculosis or viral and fungal meningitis;
3. chemicals, such as contrast dye, disinfectants, and preservatives found in local anesthetic and epidural steroid preparations; and
4. chronic compression of spinal nerves, as may occur with degenerative disc disease and/or severe spinal stenosis.

Question 4

How is the diagnosis made?

(You are seeing a 42-year-old female scheduled for umbilical hernia repair. She reports taking narcotics daily for chronic low back pain secondary to arachnoiditis. You also learn that she had a reaction to penicillin, during which she says, “it was hard to breathe”.)

Answer 4

Symptoms associated with arachoiditis include:

1. back pain that increases with activity;
2. various sensory and motor abnormalities, such as tingling, numbness, weakness, cramps, spasms, and severe shooting leg pain; and
3. bowel, bladder, and/or sexual dysfunction.

Computerized axial tomograpy and magnetic resonance imaging are often used to help establish the diagnosis.

Question 5

How do you treat arachnoiditis?

(You are seeing a 42-year-old female scheduled for umbilical hernia repair. She reports taking narcotics daily for chronic low back pain secondary to arachnoiditis. You also learn that she had a reaction to penicillin, during which she says, “it was hard to breathe”.)

Answer 5

Since there is no cure for arachnoiditis, the treatment is similar to that utilized for other chronic pain conditions.

Treatment modalities include –

• physical therapy,
• pain medications (i.e. NSAIDs, narcotics,
• corticosteroids,
• anti-spasm drugs,
• anti-convulsants (help with burning pain),
• intrathecal pump placement,
• transcutaneous electrical nerve stimulation, and/or
• a spinal cord stimulator.