Spontaneous Bacterial Peritonitis

As I mentioned in my introductory blog, one thing I will be doing is sharing with you, the reader, cases that I see clinically at work. Working at a University Hospital, I have the opportunity to see and learn about a wide array of pathologies. I got the idea from an article I read that said you should always carry a 3X5 card in your shirt pocket when in clinic. If you see a patient with a particular disease that you’ve never heard of or know nothing about, jot it down, look it up, and learn about it. Add your findings to the 3X5 card and store them in a box, much like you’d use to store recipes in. I thought this would be a fun way of learning something each week that will surely translate into my training as a PA, so I’m now doing that and want to share with my followers. At the end of the year, I will have assembled a box full of new knowledge that I can refer back to at points along the way.

On my job, I get to round with interns, medical students, residents, fellows and attending physician’s in the ICU. This week there was a patient that had SBP. Not knowing what that was, I took the opportunity to ask a resident that I have befriended. After telling me a little about SBP, I pulled an article and will share with you the highlights of Spontaneous Bacterial Peritonitis (SBP).

Introduction:

SBP is an infection of ascetic fluid without a definitive abdominal source that can be treated surgically. SBT is common in cirrhosis of the liver with concomitant ascites. Patients that survive such an infection have 1 and 2 year mortality rates of 70% and 80% respectively, and the recurrence rate within a year of the initial infection, ranges from 40-70%.

Pathogenesis:

The pathogenesis of SBT is caused by a prolonged bacteremia, secondary to a compromised host, intrahepatic shunting, colonized blood, and ineffective antibiotics. Predictors of SBT are an increased bilirubin >2.5mg/dL and low ascetic protein level < 1g/dL. The typical offending pathogens are gram-negative rods and streptococci.

Signs and symptoms:
Some common signs and symptoms that are seen with SBT are listed here

• Fever, abdominal tenderness
• GI bleeding, nausea & vomiting
•  Chills, change in mental status
• Cytologic analysis of fluid obtained by paracentesis is the best way to assess and identify SBP (see link for procedure) https://www.youtube.com/watch?v=zyvHGmigvD0
• The best information is relative to the neutrophil level ---> 250-500 cells/mL
• pH and lactate measurement of fluid is not particularly helpful or useful

Primary SBP vs. Secondary SBP:

Primary SBT has the following:

• monomicrobic
•  PMN’s >250 cells/mm³
• Gram negative rods (GNR’s)

Secondary SBP:

• Total protein >1g/dL
• Glucose < 50mg/dL
•  LDH > upper limits of normal (ULN)
• PMN’s > 250 cells/mm³

Treatment:

The treatment for SBT is typically pharmacologic in nature and the antibiotics used will depend on local epidemiologic patterns. Empirical antibiotic s are recommended. Several antibiotics were mentioned in the article I read, but two of the common ones were Ceftaximine and Ceftriaxone. After the initial paracentsis, it is recommended that a second diagnostic paracentesis be done 48 hours later, in order to assess the efficacy of the antibiotics being used for treatment. The literature says that is there is not a 25% or greater improvement in the decrease of PMN’s. If you aren’t able to reduce the nutrophile count by 25%, it is seen as a failure of treatment.

Albumin:

The single largest predictor of death in SBP is renal failure. With that, the question of Albumin administration has to be asked. Who gets Albumin?

•  serum Bilirubin > 4mg/dL
• serum Creatinine > 1mg/dL
• BUN > 30mL/dL

It should also be mentioned that the dose for Albumin be limited to 100 g/dose. If the SBP is complicated, then Albumin should not be administered. If renal function is NOT compromised and the is NO encephalopathy, then Albumin should not be administered

Prophylaxis:

Prophylactic treatement should be reserved for patients at greates risk for SBP. So, who is at greatest risk for the development of SBT?

•  Past history SBP
• Upper GI bleed
• Low total protein level in ascetic fluid

Reference:

1. Alaniz, C., Regal, R.E. Spontaneous Bacterial Peritonitis. P.T. 2009 Apr; 34(4) 204-210.