Lecture 7: Hemoperitoneum/Peritonitis

What is hemoperitoneum or hemoabdomen?

abnormal accumulation of blood in the peritoneal cavity

What are the potential causes of hemoperitoneum?

1. traumatic: HBC, kicks, falls

2. nontraumatic: neoplasia, nontraumatic adrenal gland rupture, nonmalignant disease (GDV, splenic torsion, vitamin K antagonists etc)

What is the #1 nontraumatic cause of hemoperitoneum in dogs and cats?

neoplasia

What is the typical clinical presentation of a hemoperitoneum case?

signalment:

• younger = more likely trauma

• older = more likely neoplasia

hx:

• Trauma or suspected trauma

• Neoplasia is usually nonspecific

• Previous hemorrhage

• Access to toxins or rodenticide

• Previous diagnosis of a mass

• Previous surgery or diagnostic procedure

How do hemoperitoneum cases present upon physical exam?

• External signs of trauma

• Abdominal distension (+/- fluid wave)

• Abdominal tenderness

• Contusion / Discoloration of abdominal wall

• Bulging umbilicus

What is the classic description of hemoabdomen rads?

loss of abdominal detail with focal or generalized “ground glass” appearance

What type of imaging is more sensitive with small quantities of fluid for a hemoabdomen case?

ultrasound - AFAST exam

Describe this radiograph.

Loss of abdominal detail with focal or generalized “ground glass” appearance

What type of imaging is this?

AFAST exam

What are the four views of an AFAST exam?

1. diaphragmaticohepatic

2. splenorenal

3. cystocolic

4. hepatorenal

True or false: Clinicopathologic abnormalities in dogs with hemoabdomen are typically similar regardless of the cause of the abdominal bleeding.

true

How is hemoperitoneum diagnosed?

by finding nonclotting bloody fluid in abdomen by abdominocentesis or diagnostic peritoneal lavage (DPL)

What is replacing the use of DPL in trauma?

FAST exam

What are the negative of DPL?

• invasive

• low specificity

• false negatives: retroperitoneal injury, ruptured diaphragm

True or false: trauma patients with hemoabdomen that stabilize after medical management still require surgery.

false - they often do not

How are hemoabdomen cases medically managed?

• IV fluid replacement therapy

• Blood transfusion

• Tight abdominal wrap? (during stabilization)

• Oxygen therapy

What preoperative issues need to be managed before a hemoabdomen surgery?

• stabilize shock

• correct fluid, acid-base, electrolyte, and CV abnormalities

• blood transfusion if PCV< 20%, hypoxic from anemia or respiratory depression, or if ongoing bleeding is expected

Why should barbiturates and acetylpromazine be avoided in hemoabdomen patients?

barbiturates: cause splenic congestion

acetylpromazine: RBC sequestration, hypotension, impact on platelet function

What are the indications for hemoabdoment surgery?

• Undetermined source of hemorrhage

• Uncontrolled hemorrhage

• Evaluation/Removal of intra-abdominal neoplasia

What is primary generalized peritonitis?

Spontaneous inflammation of the peritoneum with no obvious intra-abdominal reason for leakage of bacteria

What is secondary generalized peritonitis?

inflammation of peritoneum in conjunction with an intra-abdominal reason for the inflammation/infection (infectious or noninfectious)

What is the predominant form of peritonitis in dogs?

secondary generalized

What most commonly causes secondary generalized peritonitis?

bacteria usually originating from contamination from GI tract (sx wound dehiscence, GI neoplasia)

Besides bacteria from the GI tract, what are some other causes of secondary generalized peritonitis?

• Gal Bladder perforation, rupture, or neoplasia

• Gastric or intestinal foreign bodies

• Intussusception

• Mesenteric avulsion

• GDV

• Cystocentesis

• Necrotizing Cholecystitis

• Pancreatic Abscess

• Prostatic Abscess

• Foreign body penetration of the body wall

Why is differentiating primary from secondary generalized peritonitis important?

because surgery is not routinely performed in Primary Generalized Peritonitis but is required in Secondary Generalized Peritonitis

Describe the bacterial association in peritonitis?

• Gram-positive bacteria more common in Primary

• Gram-negative bacteria more common in Secondary

• Primary are more likely to be monobacterial

• Secondary are more likely to be polybacterial

What is the typical presenting complaint for peritonitis cases?

• lethargy, anorexia, V/D, and/or abdominal pain

• cats more likely to present with lethargy, depression, and anorexia, than abdominal pain or vomiting

When suspected peritonitis, what needs to be ruled out in a sick intact female dog?

pyometra

What is usually found during the PE of a peritonitis case?

• Abdominal palpation often causes pain

• Vomiting, Diarrhea

• Abdominal distention

• Pale mm, Prolonged CRT

• Tachycardia may indicate shock

• Dehydration and arrhythmias may occur

What is usually seen on a peritonitis radiograph?

• Intestinal tract may be dilated with air or fluid or both

• Free abdominal air → Rupture of a hollow organ, Gas-producing anaerobic bacteria

• Localized peritonitis , secondary to pancreatitis, may cause a “sentinel loop” by making the duodenum appear to be fixed and elevated

What is the most common laboratory finding in peritonitis?

marked leukocytosis

What was a prognostic indicator of peritonitis in cats, with higher levels associated with poorer prognosis?

lactate levels

Why is surgery not indicated if a diagnosis of primary peritonitis is made preoperatively?

• May result in worsening of underlying disease

• Associated with increased morbidity

What are the medical management goals of peritonitis?

1. Eliminate cause of contamination

2. Resolve the infection

3. Restore normal fluid & electrolyte balance

What are the indications for abdominocentesis?

• Shock with no apparent cause

• Undiagnosed abdominal disease

• Suspicion of post-op GI dehiscence

• Blunt or penetrating abdominal injury (gunshot. Dog bite, HBC)

• Abdominal effusion

• Undiagnosed abdominal pain

When should diagnostic peritoneal lavage be performed?

in animals suspected of having peritonitis if abdominocentesis and 4- quadrant paracentesis are unsuccessful in obtaining fluid for analysis and ultrasonography (AFAST) or CT imaging are not available

When is exploratory surgery indicated in peritonitis cases?

• Cause of peritonitis cannot be determined

• Bowel rupture

• Intestinal obstruction (e.g., bowel incarceration, neoplasia)

• Mesenteric avulsion is suspected

Why is intraoperative peritoneal lavage controversial?

• could disseminate localized peritonitis

• if too much fluid is not removed the fluid inhibits the body’s ability to fight off infection, probably by inhibiting neutrophil function

What is the most appropriate lavage fluid for intraoperative peritoneal lavage?

warmed isotonic saline

True or false: there is no evidence that adding antiseptics or antibiotics to intraoperative peritoneal lavage fluids is of benefit.

true

How is open abdominal drainage performed?

a small section of abdominal incision left open → sterile wraps placed around wound and changed based on fluid drainage and external soiling

What are the complications of open abdominal drainage?

• Persistent fluid loss

• Hypoalbuminemia

• Weight Loss

• Adhesion of abdominal viscera to bandage

• Contamination of the abdominal cavity with cutaneous organisms

What are the advantages of open abdominal drainage?

• Improved metabolic condition

• Fewer abdominal adhesions

• Fewer abscesses

• Access for repeated inspection/exploration

What are the disadvantages of open abdominal drainage?

• Hypoalbuminemia

• Hypoproteinemia

• Anemia

• Nosocomial Infections

What type of drainage is effective in dogs and cats with generalized peritonitis if effusion is serous in nature and involves far less time and effort than OAD?

closed suction drainage

What is this?

Jackson-Pratt Drainage Catheter

How is an abdominocentesis performed?

• Insert 18-20g 1 ½ inch over-the-needle catheter (with added side holes) at most dependent point

• Do not attach syringe

• Allow fluid to drip from catheter → Collect in sterile EDTA tube → Submit samples for culture (aerobic & anaerobic) → Make smears

• If fluid does not drip, use a 3-cc syringe with gentle suction

How is a diagnostic peritoneal lavage performed?

• Make 2 cm skin incision caudal to umbilicus

• Hemostasis to avoid false positives

• Small incision into the linea alba → Hold edges of incision while peritoneal lavage catheter is installed (without trocar)

• Direct catheter caudally into pelvis

• Gently aspirate

• If negative aspiration, attach catheter to IV line with bag of warm sterile saline (20 ml/kg) and infuse into abdominal cavity

• Roll patient gently side-to-side to disperse fluid

True or false; DPL does not reliable exclude significant retroperitoneal injury or hemorrhage.

true

When can the abdominal incision from open abdominal drainage be closed?

when bacterial numbers have declined and neutrophils are no longer degenerative (usually 3-5 days post-op)

How is closed suction drainage performed?

• In cats and small dogs, place one drain between the liver and the diaphragm

• In large dogs, place a second drain into the caudoventral abdomen

• Exit the drain tubes through the body wall thru a paramedian stab incision

• Suture drains to the abdominal skin with a Roman Sandal or Chinese Finger Trap

• Close the abdomen routinely

What is the roman sandal suture pattern (chinese finger trap)?

suture pattern to attach drain to abdominal skin

What is the recommended suture material in peritonitis cases?

• Use monofilament nonabsorbable suture or slowly absorbable suture

• Do NOT use braided suture

• Do NOT use suture that is rapidly degraded

What post-op assessments are required after peritonitis procedures?

• Fluid therapy continued (especially if OAD)

• Monitor electrolytes, acid-base, serum protein and correct as required

• Nasal oxygen if sepsis

• Ensure adequate caloric intake

• Consider plasma if hypoproteinemic

• Analgesia

What is the prognosis of peritonitis cases?

• generalized peritonitis = guarded

• many survive with aggressive therapy