Surgical Management of Peritonitis

What physical exam findings are consistent with peritonitis?

"depression" dehydration abdominal splinting standing or recumbent +/- fever weight loss reduced/absent bowel sounds shock

How should a patient with peritonitis be medically managed prior to surgery?

-Aggressive shock treatment-->Start correcting fluids and electrolyte abnormalities as tests are being done --->crystalloid, colloid, & packed RBCs (if needed) -Administer IV antibiotics (ampicillin/enrofloxacin, clindamycin/enrofloxacin, cefazolin/clindamycin)

What factors influence decision of when to do surgery?

-Depends on the suspected cause -Patient status at presentation -Duration of signs -Response to intial medical management (usually need rapid intervention)

What is involved in postoperative care?

-Hydration and electrolytes (crystalloid and colloid support) -Nutrition -Serum proteins (esp. albumin) -Correct antibiotics based on culture and sensitivity -General nursing care -Serial monitoring of CBC, chem panel -low dose SQ heparin to minimize septic thromboemboli potential

What are the goals of surgery with Peritonitis?

-ID/Repair the cause -Debride the abdomen & copious lavage/suction until clear fluid retrieved -Samples for culture & sensitivity, histopath, cytology, gram stain, special stains -Evaluation of serosal surfaces and extent of inflammation/infection/adhesion -Provide drainage -Nutrition considerations (place gastrostomy/jejunostomy/esophagostomy feeding tube if indicated) -Decision for closure (close or keep opwn to drain the abdominal cavity)

What can peritonitis occur secondary to?

-Penetrating or Blunt trauma -Ruptured viscus and leakage -Transmural migration of bacteria (bowel obstruction, pyometra, pyelonephritis, pancreatitis, prostatitis) -Tumor invading into organ lumen with resulting leakage of organ luminal contents into the peritoneal cavity -Abscess of liver/spleen/pancreas/prostate with leakage of abscess material and/or transmural migration of bacteria -Foreign body (grass awn, plant material that enters via skin or oral mucosa and migrates anywhere in the body, migration out of GI tract -Iatrogenic

What are the defense mechanisms of the peritoneal cavity?

-Vasodilation and outpouring of serofibrinous fluid and WBCs -Adynamic ileus: lack of peristalsis in attempt to prevent intra-abdominal spread of irritating agents -Mobilization of omentum, intestinal loops, and mesentery in attempt to confine irritating agent to one area of abdomen -Rapid absorption of irritating agents by peritoneal lymphatics and transport to the RE system for removal

How is peritonitis diagnosed?

-history and PE -2-view radiographs (free air/fluid, gas distended bowel) --->contrast radiographs -Abdominal ultrasound -Peritoneal aspiration (4 quadrant paracentesis) & cytology -Baseline CBC, chem, U/A (BUN/creatinine may be increased with urinary tract perforations) -Abdominal exploratory surgery to define cause

What may be indicators of abdominal closure?

Acute problem Grossly normal tissue Relatively healthy patient close with 1-2 suction drains to collect and monitor peritoneal fluid Petechia/ecchymotic hemorrhages on serosal surface=early peritonitis (+1 drain if relatively health)

What is peritonitis?

An inflammatory process that involves all or part of the peritoneal cavity

What are the advantages of open abdomen drainage?

Drains entire cavity Easy access to re-explore abdomen It works!

How is the open abdomen bandaged after surgery?

Immediately after surgery, circumferential abdominal bandage using sterile absorbable bandaging materials: Sterile disposable baby diaper immediately against body wall over the gap, then standard bandage using sterile cast padding/roll gauze/tape or vetrap changed twice daily

What is the pathophysiology of peritonitis?

Inciting cause-->activation of peritoneal defenses-->sequestration of a large amount of fluid/electrolytes/protein in abdominal cavity-->hypovolemic shock + low oncotic pressure absorption of bacteria+bacterial toxins-->septic shock +vascular pooling ileus-->gas distention of intestine + pain-->(if ileus severe + gas distention)-->inadequate ventilation due to limited diaphragmatic movement deterioration of patient occurs quickly (hours)

Can the abdomen be left completely open for "open abdomen" after surgery?

It depends: Caudal 1/3-1/2 incision is closed cranial part left open sutures placed to approximate body wall plates leaving midline gap of 1-2 cm to allow for drainage Females can have the entire incision left open if bandage covers the caudal part adequately Males always have caudal aspect closed to minimize urine contamination

What are the disadvantages to leaving the abdomen open?

Potential for ascending infection (minimal risk if done correctly) large losses of fluids/protein/electrolytes Labor intensive (bandage changes/maintenance) Expensive

What are sequelae to peritonitis?

Resolution Death from sepsis Local abscess (local drainage or excisional surgery) Adhesions (may result in bowel obstruction-->unusual)

What are clinical signs associated with peritonitis?

abdominal pain abdominal distension anorexia vomiting lethargy

How can blunt trauma cause peritonitis?

blunt trauma-->visceral ischemia from avulsion of blood vessels-->subsequent organ luminal bacterial translocation into peritoneal cavity

What is the only primary peritonitis?

feline infectious peritonitis (FIP)

What are some iatrogenic causes of peritonitis?

forgetting gauze during surgery, leaving blood/debris in peritoneal cavity, leakage from hollow viscus suture line from poor technique/wrong suture material/wrong suture pattern, poor quality tissue that can't hold suture, break in aseptic technique

Follow up to open abdomen surgery

in 2-3 days, exploratory surgery to recheck-->final exploratory and closure surgery Culture and sensitivity samples remove debris/debride If CBC and chem values improving, decreased drainage, clear fluid, and abdominal tissue looks vital-->close + 1 closed suction drain installed to monitor abdominal fluid

How can penetrating trauma cause peritonitis?

inoculation of bacteria and debris into abdominal cavity +/- perforation of various abdominal structures resulting in hemorrhage and spillage of luminal contents into peritoneal cavity

What are the types of Peritonitis?

localizedd: inflammation confined to one area of the peritoneal cavity generalized: total involvement of peritoneal cavity

What is an alternative to open abdomen?

placement of 2-4 closed suction drains into abdominal cavity to provide adequate drainage; bandage required to hold drain collection devices in place and cover drain entry sites must be a local problem to use this technique (rare)

What are the possible complications with closing the abdomen?

potential for more severe sepsis increased morbidity/mortality

What is the decision to leave the abdomen open based on?

serosal surfaces amount of debris/septic fluid found potential duration of peritonitis overall condition of the patient -->sick patient with septic fluid when in doubt, leave the abdomen open for 2-3 days secure with sterile dressing material to allow drainage bandages changed BID-TID until infection is under control