Alimentary Prophylaxis Flashcards
What is the word for the movement of enteric organisms across the bowel wall?
Translocation
What is multiorgan failure?
Persistent inflammation and progressive dysfunction of 2 or more organ systems
What is the gut hypothesis?
Splanchnic hypo perfusion caused but hypoperfusion –> sepsis –> SNS activation –> splanchnic vasoconstriction
How much of the splanchnic blood supply goes to the gastric mucosa?
70-90%
What are the risk factors for stress ulcer bleeding?
Mechanical ventilation over 24 hours Coagulopathy: platelets less than 50k, INR greater than 1.5, PTT greater than 2x control Burns involving more than 30% of body Shock Sepsis Trauma TBI Renal failure Steroid therapy
What is clinically significant bleeding in the ICU?
A drop in bp or hgb by more than 2
What is the ph goal for using acid blockers in ICU?
Ph above 4
What are the 3 mechanisms of protection against microbial invasion in the alimentary tract?
- Stomach acid
- Mucosal barrier of bowel wall
- Reticuloendothelial system on extra luminal side of bowel wall
How long does ranitidine last?
6-8h
What is the typical dosing of ranitidine?
50 mg IV q 8h
How long does famotidine last?
20 mg lasts 10-15 hours
How are H2 blockers cleared?
Renally
What can happen if patients with renal failure is given H2 blockers intravenously?
They may accumulate and cause neurotoxicosis: confusion, agitation, seizures
What are the risks of using H2 blockers?
Infectious gastroenteritis
c. Dif
Aspiration pneumonia
What is MOA of PPI?
Binds irreversibly to the membrane proton pump and prevents gastric acid secretion
What are the advantages of ppi over H2 blockers?
- Greater reduction in acidity
- Longer duration of action
- Responsiveness does not diminish with continued usage
- Metabolized by the liver
What are the risks of using PPI?
Higher risk of infectious gastroenteritis
Higher incidence of hospital acquired pneumonia and C.dif
Which drug do PPI’s inhibit?
Clopidogrel because they are both metabolized by the same P450 enzyme.
Can reduce clopidogrel effect through competitive inhibition
What is the disadvantage to sucralfate?
It binds other drugs in the lumen and inhibits their absorption
Which drugs does sucralfate bind in the lumen?
Warfarin Theophylline Tetracycline Cipro Norfloxacin Digoxin Ketoconazole Phenytoin Ranitidine Thyroxin
Which drug (sucralfate or h2/PPI) was shown to cause less adverse events?
Sucralfate
What are the benefits of enteral tube feeds?
- Trophic to gastric mucosa
2. Raises ph
What is believed to be the inciting event in hospital acquired pneumonia?
Aspiration of mouth secretions into the upper airways
What bacteria is the mouth of a critically ill patient usually populated with?
Aerobic gram negative bacilli: Pseudomonas,
Why do critically ill patient get colonization of pathogenic organisms in their mouth?
The epithelial receptors change
What is the change in micro flora in the mouth directly correlated with?
The severity of illness
Who benefits most from chlorhexidine washes of the mouth?
Cardiac patients
What is chlorhexidine most effective against?
Gram positives
What is selective oral decontamination?
Direct application of antibiotic to the buccal mucosa
What is the formula of SOD?
Gentamicin (gram negatives)
Colistin (candida)
Vanc (gram positives)
What are the benefits of SOD.
- Reduced incidence of hospital acquired pneumona
- Reduced incidence of bacteremia by gram negatives
- Decline of tracheal colonization
What is the SDD formula?
10 ml of polymixin, tobramycin, amphotericin
Who is SDD recommended for?
ICU patients who will stay for more than 72 hours because it takes a week to decontaminate the gut
What organ metabolizes PPi?
Liver
What drug should not be used with PPi?
Plavix because it decreases its anti platelet activity
