More than 3 million new cases of Clostridium difficile
infection (CDI) occur each year in acute-care and long-term care
facilities in this country. A spore-forming bacterium most commonly
found in the GI tract, C. difficile produces toxins noxious to
the intestinal lining, where it alters epithelial cells. Disturbance of
these cells can cause a wide range of signs and symptoms, from mild
abdominal pain with watery diarrhea to painful abdominal cramping,
fever, and bloody stool, possibly progressing to toxic megacolon. CDI
accounts for roughly 14,000 deaths each year in the United States.
Traditional treatment varies with disease severity. For mild CDI,
initial treatment includes metronidazole; for severe CDI, patients
typically receive vancomycin. The newest drug used in CDI therapy is
fidaxomicin. This drug may be superior to vancomycin in decreasing CDI
recurrence, although it’s significantly more expensive.
Emerging concerns
Emerging concerns
CDI commonly follows exposure to antibiotics, which alter the
intestinal flora and cause an imbalance of the natural gut flora.
Initial treatment involves discontinuing the suspected causative
antibiotic and starting oral vancomycin, metronidazole, or fidaxomicin.
Unfortunately, more than 1 million CDI patients who receive these
drugs experience treatment failure. One possible explanation is the
emergence of multiple-relapse CDI (MR-CDI). Relapse rates are nearing
30% in patients with first-time CDI and exceed 65% for patients with a
history of recurrent CDI.
To make matters worse, a hypervirulent strain of C. difficile,
known as BI/NAP1/027, recently emerged. Experts believe this strain
accounts largely for the increased CDI incidence. First noted in the
early 2000s in North America and Europe, this strain differs from other C. difficile strains in four dangerous ways:
- causes increased toxin production
- leads to more severe diarrhea
- involves increased spore production
- causes fluoroquinolone resistance.
Emergence of the new strain underscores the importance of prevention. (See the box below.)
|
Crucial preventive measures
Preventing the spread of C. difficile is crucial to reducing the incidence of CDI. Prevention requires a threefold approach: preventing person-to-person transmission, minimizing risk factors, and practicing antimicrobial stewardardship through the following measures:
|
Reviving an old treatment
An old treatment may be the answer to the current MR-CDI epidemic. Fecal microbiota
transplantation (FMT), also called fecal bacteriotherapy, was described
as long ago as the 17th century. The similar veterinary practice of
transfaunation (transfer of symbiotic fauna from one host to another)
was used to cure colitis in farm animals. In 1958, before C.difficile
was discovered as a causative pathogen, FMT was used successfully to
treat patients with antibiotic-associated pseudomembranous colitis.
(See the box below.)
More than 500 bacterial species inhabit the intestinal tract,
creating a symbiotic environment within this microbial organ. Scientists
are starting to recognize this symbiosis as an important element in
immunity; the gut provides protection from pathogens and promotes
epithelial-cell proliferation and nutrient production and metabolism.
C. difficile flourishes in the environment around us.
Intestinal flora protect us from it, but antibiotics can disturb the
balance, allowing C. difficile to proliferate, overgrow, and
cause infection. FMT reconstitutes the normal intestinal flora, which
explains its overwhelming success in treating CDI.
Candidates for FMT include patients who:
- have had three episodes of recurring CDI with 6 to 8 weeks of antibiotic failure, or two recurrent CDIs requiring hospitalization
- have moderate CDI but haven’t responded to antibiotic therapy
- have severe colitis from C. difficile and are decompensating and unresponsive to antibiotics.
Ineligible patients typically include those receiving
immunosuppressant agents or chemotherapy, those who’ve had a recent bone
marrow transplant, and those with advanced HIV/AIDS. Patients with
toxic megacolon aren’t eligible for FMT because that condition is a
surgical emergency.
FMT isn’t limited to patients with CDI. It also has been used
successfully in patients with chronic severe constipation and in those
with inflammatory bowel disease (such as Crohn’s disease or ulcerative
colitis) who’ve failed other therapies.
Fecal donor selection
Fecal donor selection
FMT requires a healthy donor to provide stool for transplantation.
Donors are recommended by the patient; they may be healthy relatives or
close friends. Potential donors must undergo an extensive interview to
assess lifestyle and health history, as certain laboratory tests may not
detect early infection. Exclusionary criteria include tattoos or body
piercings within the last 6 months, a history of incarceration,
high-risk sexual behaviors, communicable illnesses or antibiotic
treatment within the past 3 months, and such GI conditions as irritable
bowel syndrome or chronic diarrhea. Donor stool is tested extensively
for pathogens, including C. difficile, ova and parasites, Helicobacter pylori, Giardia, and Cryptosporidium. Donor blood is tested for human immunodeficiency virus, syphilis, and hepatitis A, B, and C.
For 5 days before stool collection, donors must refrain from eating
foods to which the recipient may be allergic. They should notify the
physician if they become ill with fever, diarrhea, or vomiting between
screening time and donation. They are given a urine collection hat, a
stool specimen cup prelabeled with their name, a tongue depressor, and a
biohazard bag for transporting stool to the hospital.
Patient preparation and education
Patient preparation and education
The notion of placing someone else’s feces into one’s body sounds
unappealing—unless you’ve been suffering for month or years with
recurrent CDI. Many patients are willing to try anything. For them, FMT
is a welcome option. The goal of FMT is to reduce diarrhea frequency and
decrease the infectious burden.
FMT usually is done in the inpatient setting. The physician explains
the procedure to the patient and obtains informed consent. For 3 days
before FMT, the patient is pretreated with oral vancomycin 125 mg three
times daily; the drug is discontinued the day before the procedure. The
patient receives a proton-pump inhibitor the evening before and morning
of the procedure to reduce gastric acid in the stomach.
When providing patient education, be sure to include the FMT process,
donor selection, and the method that will be used to instill the stool.
Also teach the patient and family how to prevent spread of CDI at home,
including proper hand hygiene with soap and water and use of bleach to
clean environmental surfaces. Encourage the patient to notify all
treating healthcare providers of their history and CDI treatment, and
urge them to question any antibiotic prescription.
Prior to Procedure
Prior to Procedure
Donor stool preparation is done using standard precautions. Usually,
donor stool is instilled within 6 hours of the donor’s bowel movement.
First it’s diluted using preservative-free sterile saline solution.
Next, a fecal slurry is made by manually stirring it or using a blender
until the stool is of a consistency that allows for aspiration. The
fecal slurry is filtered using gauze or a mesh strainer to remove as
much particulate as possible, and is instilled immediately.
Several methods can be used to deposit the slurry—colonoscopy,
retention enema, or nasogastric (NG) tube. No established guidelines
exist for the best instillation method or amount of slurry to instill;
clinicians should consider the patient’s size and instillation method.
For an average-size adult, 50 to 200 mL are instilled via NGT; for
colonoscopic instillation, 250 mL to 500 mL are instilled.
If the patient is receiving the slurry through an NG tube, additional
nursing considerations apply. Once the physician prepares and filters
the stool, the nurse draws up the slurry into a clean 60-mL syringe and
injects the prescribed amount slowly (50 mL over 2 to 3 minutes) into
the NG tube, followed by a 50-mL flush of saline solution.
Postprocedure care
Postprocedure care
For at least 2 hours after the procedure, keep the head of the bed
elevated at least 30 degrees to reduce reflux and aspiration. Patients
may experience belching, abdominal cramping, and nausea, but these
symptoms should last only a few hours. They may resume their normal diet
or tube feedings 2 hours after the procedure.
Many patients report feeling better within 24 hours of FMT. Be sure to include the FMT process, donor selection, and the method that will be used to instill the stool. Also teach the patient and family how to prevent spread of CDI at home, including proper hand hygiene with soap and water and use of bleach to clean environmental surfaces. Encourage the patient to notify all treating healthcare providers of their history and CDI treatment, and urge them to question any antibiotic prescription.
Procedure
Donor stool preparation is done using standard precautions. Usually,
donor stool is instilled within 6 hours of the donor’s bowel movement.
First it’s diluted using preservative-free sterile saline solution.
Next, a fecal slurry is made by manually stirring it or using a blender
until the stool is of a consistency that allows for aspiration. The
fecal slurry is filtered using gauze or a mesh strainer to remove as
much particulate as possible, and is instilled immediately.
Several methods can be used to deposit the slurry—colonoscopy,
retention enema, or nasogastric (NG) tube. No established guidelines
exist for the best instillation method or amount of slurry to instill;
clinicians should consider the patient’s size and instillation method.
For an average-size adult, 50 to 200 mL are instilled via NGT; for
colonoscopic instillation, 250 mL to 500 mL are instilled.
If the patient is receiving the slurry through an NG tube, additional
nursing considerations apply. Once the physician prepares and filters
the stool, the nurse draws up the slurry into a clean 60-mL syringe and
injects the prescribed amount slowly (50 mL over 2 to 3 minutes) into
the NG tube, followed by a 50-mL flush of saline solution.
Postprocedure care
Postprocedure care
For at least 2 hours after the procedure, keep the head of the bed
elevated at least 30 degrees to reduce reflux and aspiration. Patients
may experience belching, abdominal cramping, and nausea, but these
symptoms should last only a few hours. They may resume their normal diet
or tube feedings 2 hours after the procedure.
Many patients report feeling better within 24 hours of FMT. Be sure
to document continued diarrhea, as FMT may need to be repeated after 5
days if the diarrhea continues. FMT is deemed successful if symptoms
resolve and don’t recur for 8 weeks; at that point, the patient is
considered clinically cured. Patients don’t need to be retested for C. difficile, as they’re likely to remain colonized with the bacteria but not infected. Patients are tested only if they’re symptomatic.
In patients who’ve undergone FMT, the cure rate for MR-CDI is nearly
90%. Yet barriers to this procedure persist; for instance, most
insurance companies don’t cover donor screening costs. Also, few
hospitals have FMT protocols, making preparation and administration
difficult.
As a nurse, you may come in contact with patients who have MR-CDI.
You can play a crucial role in reducing MR-CDI by disseminating
information about FMT. The next time you encounter a patient with
MR-CDI, consider recommending FMT to the healthcare team.
Amy Marinski is an infection control practitioner at Orlando Regional Medical Center in Orlando, Florida.
No comments:
Post a Comment