clinmed - c. diff colitis and ischemic bowel dz Flashcards
What is the first thing to assess when an older pt suddenly develops new onset diarrhea?
- dehydration
- know the clinical signs of fluid loss
- don’t kill their kidneys
c. diff bacteria
- spore forming, gram+ anaerobic bacillus
- normal part of flora in 5-15% of people
prevalence and issues with c. diff
- use of broad spectrum abx has increased its prevalence
- strains becoming more virulent
- strains becoming more resistant to fluoroquinolones
pathogenesis process of c. diff
- abx given
- normal bacterial reduced
- c. diff uninhibited by the normal bacterial that normally suppress it
- additional access to conolic nutrients
- c. diff proliferates
what determines if c. diff develops into disease or not?
- if the bacteria lacks the gene for toxin production, no dz develops
- if ti produces toxins A and B, it may cause colitis
damage caused by c. diff
- damages colonocytes
- leads to inflammation and in some cases pseudomembranous colitis
complications of infection w/ c. diff
- pseudomembranous colitis
- toxic megacolon
- perforation of the colon
- sepsis
Who is at risk for c. diff?
- abx exposure (esp broad spectrum)
- PPI use
- GI surg
- long stay inpatient
- co-morbidities
- immunocompromised
- advanced age
- 80% of c. diff infections are related to healthcare
- what is this called?
iatrogenic cause
clinical presentation of c. diff
- watery diarrhea w/ characteristic foul odor
- fever
- appetite loss (weight loss)
- nausea
- abdominal pain
Can a pt be colonized w/ c. diff, even the toxin producing kind, and NOT show signs of infection/sickness?
YES
lab results in c. diff
- high WBC on CBC
- low albumin on BMP
- check the stool
What stool test do you order when you suspect c. diff?
- c. diff toxin by PCR (genetic test NOT culture)
- highly sensitive and specific for the TOXIN producing bacteria
- rapid turn around (next day)
Why is a stool culture not usually used in diagnosing c. diff?
- it’s sensitive however will get false positives
- labor intensive and results take 48-96 hrs
When is the antigen test for c. diff useful?
- in two step testing processes (inpatients and nursing homes)
- very rapid (<1) but nonspecific
What testing should NOT be used for c. diff?
toxin testing by enzyme immunoassay
tx of c. diff
- dc the broad spectrium abx
- IV fluids if needed
- Metronidazole 500 mg TID or 10 days
- isolation precautions
What abx should be used if the pt has recurrent c. diff or has already been treated w/ metronidazole?
vancomycin 125 mg QID for 10 days
Tx for severe c. diff case/hospitalized pt
- oral vanc
- IV metronidazole
- vanc enemas
what is the bacteriotherapy tx option for RECURRENT infections w/ c. diff?
- fecal transplant
- performed by colonoscopy
- cure rates in the >80% range
tips in preventing c. diff infections
- appropriate use of abx
- proper isolation/contact precautions for those infected
- cleaning and disinfection of equipment and environment
- alert staff quickly
- pt. and family education (hand sanitizers DONT kill spores)
pseudomembranous colitis
- SEVERE form of c. diff colitis
- very sick and hospitalized pts have high rate of mortalitiy
In a pt w/ pseudomembranous colitis, what is the next step in testing?
-CT to look for toxic megacolon
What pseudomembranous colitis patients do you consider surgery in?
- shock (altered mental status, organ dysfunction, lactic acidosis)
- peritonitis
- significant leukocytosis
- failure to improve on medical therapy for 5 days
ischemic colitis
- MC form of intestinal ischemia
- “heart attack of the gut”
- can be d/t a decrease in colonic perfusion OR atherosclerosis
where does ischemic colitis often occur?
- splenic flexure (#1)
- descending colon
- rectosigmoid colon
- (watershed areas)
precipitating causes of ischemic colitis
- often NOT identifiable
- possibly hypotension, sepsis, MI, heart failure, surgery
clinical presentation of ischemic colitis
- older pt w/:
- diarrhea** MC
- hematochezia common
- abd pain (usually mild)
- abd tenderness
- not severely ill appearing
- not typically life threatening
what is the preferred test for diagnosing ischemic colitis?
-colonoscopy WITHOUT bowel prep
although plain radiographs aren’t usually helpful in diagnosing ischemic colitis, what would be the sign on one?
thumbprinting
other imagingin ischemic colitis
- US w/ doppler shows flow changes
- CT can appear normal
Tx of ischemic colitis
- IV fluids
- NPO, bowel rest
- abx
- GI consult for colonoscopy
- surgical consult
- surgical resection if severe
What is the clinical presentation of acute mesenteric ischemia?
- very sick
- acte and SEVERE abd pain
- n/v
- +/- diarrhea and hematochezia
- ***pain WAY out of proportion to PE
- usually > 60 yo
cause of acute mesenteric ischemia
blockage of artery that feeds bowel
what could you possibly see in the past medical hx of a pt w/ acute mesenteric ischemia
- a. fib
- thrombosis
- prior emboli
- risk of clot
- hx of atherosclerosis
Diagnosis of acute mesenteric ischemia
- needs to be made quick! - mortality is 70-90% if diagnosis is delayed
- contrast CT is best for initial eval
- CTA is most sensitive
classic radiological finding in acute mesenteric ischemia
thumb printing
tx of acute mesenteric ischemia
- surgical consult stat
- medical emergency
- revascularize if possible, if not resect bowel
Chronic mesenteric ischemia
- narrowing of blood vessels that supply the intestines
- caused by atherosclerosis
chronic mesenteric ischemia is most commonly found in what population?
- W>M
- >60 yo
risk factors for chronic mesenteric ischemia
- smoking
- DM
- HTN
- dyslipidemia
sx of chronic mesenteric ischemia
- abdominal pain after meals –> anorexia/change in eating habits
- weight loss
- n/v
- constipation or diarrhea
diagnostic testing for chronic mesenteric ischemia
- CTA scan*
- CT, Xray and others to r/o other conditions like obstruction
- ateriogram, doppler US, MRA
tx of chronic mesenteric ischemia
- anticoagulant meds
- angioplasty and stenting
- surgery if that fails: endarterectomy, bypass vessel or remove/repair aneurysm
