Evaluation and Emergency Management of the Trauma Patient - Abdominal Trauma

In cases of potential abdominal trauma, what exactly are we looking for and analyzing?

FLUID in the abdomen

1. Abdominocentesis

2. Fluid categorisation

3. Fluid analysis and Smear

What is the POCUS technique for viewing the abdomen?

A-FAST

Has 4 major points that need to be assessed:

• Spleno-renal

  • Left flank view to asses splenorenal interface and areas between the spleen and body wall

• Cysto-colic

  • Midline bladder view to assess the apex of the bladder

• Hepato-renal

  • Right flank view to asses the hepatorenal interface and areas between intestinal loops, right kidney, and body wall

• Diaphragmatic-hepatic

  • Sub-xiphoid view to evaluate the hepatodiaphragmatic interface, gallbladder region, pericardial sac, and pleural spaces

When it comes to abdominal effusion, you will want to take a sample of the fluid and assess it via abdominocentesis. What are the 3 different classifications of fluid you could find in the abdomen?

Transudate - essentially very watery, not many proteins or cells

Modified Transudate - Increase of proteins and cells involved in inflammatory processes

Exudate - Very thick, mainly composed of neutrophils, RBCs and proteins

You will then perform a fluid analysis based on the appearance of the fluid. What are the 5 main kinds of abdominal effusion you could see?

1) Hemoabdomen - fluid is blood from an active bleed in the abdomen

• To confirm, compare PCV of fluid to PCV of peripheral blood

• If PCV of fluid is 10-25% that of the peripheral blood, you have an active bleed in the abdomen

• SOMETIMES EXACERBATED BY SPLENIC CONTRACTION

2) Uroabdomen - urine in the abdomen

• Will contain creatine or potassium, indicative of kidney damage / bladder rupture

3) Septic peritonitis - damage to the peritoneum → infection of the abdomen

• Will be nasty fluid; containing degenerate neutrophils (inflamm.), intracellular bacteria, and lactate and glucose

4) Intestinal perforation - Feces / GI material in the abdomen

• Intra/extracellular bacteria present in fluid

• Particulate material

5) Bile peritonitis - bile free in the abdomen

• Indicative of stomach, liver, or gallbladder damage

• Will be BROWN in color, containing higher bilirubin than plasma levels

• Neutrophils will be present due to inflammation from damaging bile

Further describe a hemoabdomen… what are the common causes? How do they present?

• Presence of haemorrhagic effusion in the peritoneal cavity

  • Non traumatic (idiopathic)

  • Traumatic

• Bleeding from kidneys, spleen and/or liver

• Common in RTA

• Presentation

  • Shocked/Collapsed patients

  • Secondary arrhythmias/ pulse deficits

** Can also be present in anaphylactic reactions

How would one diagnose a hemoabdomen ASIDE FROM PCV?

• Coagulation profile

• A-POCUS → blood looks shimmery on ultrasound instead of anechoic like normal fluid; due to RBCs and proteins (see image)

How would you approach initially treating and stabilising the patient? What are your options for treatment?

Goal → Manage shock and control source of bleeding

Treatment:

• Start with goal directed fluid therapy BUT

  • Hypotensive or low volume resuscitation

  • Need to not exacerbate bleeding

• Blood transfusions

• Autotransfusions

  • Using the patient’s own blood from the abdomen and reintroducing it to the intravascular system

    • not the cleanest 

    • If bleeding is from a cancerous mass, could spread cancer all through the body 

    • If there’s other damage, could be bad blood

    • Need to inform O of risks before performing 

Then of course put them on O2

What are the two options for management once the patient is stable?

If just a minor bleed → External pressure bandage wrap; monitor PCV

If a continuous bleed, NEEDS SURGICAL INTERVENTION

• most will btw

Further describe a uroabdomen… what causes it? What are the two different classifications of a uroabdomen?

• Leakage of urine to peritoneal or retroperitoneal

• Loss of integrity of urinary system (Kidneys to intraabdominal urethra)

• Classified by origin of leakage:

  • Uroperitoneum

    • Intraabdominal urethra

    • Bladder

    • Distal urether

  • Uroretroperitoneum

    • Kidneys

    • Proximal urether

What is one consequence of having urine leaking out into the abdomen? Think about what the kidney’s job is…

The body will try and maintain homeostasis as urine (which contains K+, Creat, Urea, and H2O) sits in the abdomen.

Results in intravascular disequilibrium:

• Increased K → hyperkalemia

  • VERY NEGATIVE IMPACT ON THE KIDNEYS AND HEART

    • Kidneys → increased GFR, Aldosterone, Na/K ATPase → increased urine production → even MORE urine in abdomen

    • Heart → more potassium = increased action potentials → bradyarrhythmias

• Increased Urea → azotemia

• Increased abdominal H2O → DECREASED IV ELECTROLYTES

  • Will leave circulation to maintain osmolarity

  • Hyponatremia (decreased Na+)

  • Hypochloremia (decreased Cl-)

How would you diagnose a uroabdomen? Are there going to be clinical signs?

• Non-specific Clinical signs

  • Bladder might or might NOT be palpable

  • +/- Urination

  • +/- haematuria before uroabdomen

• Biochemistry

  • Azotaemia

  • Hyperkalaemia 

• Imaging - not the best either

  • APOCUS

  • Contrast radiography

Most surefire way is via fluid analysis

• Test for creatinine and potassium in the free fluid

  • Still should ALWAYS compare the ratio between the creat in the fluid and the creat in blood

• Also perform a smear of the fluid to rule out any bacteria

How would you then manage a uroabdomen and treat it?

• Fluid resuscitation

• Urinary catheterisation - need to get as much urine out as you can

• Abdominal drainage - need to restore homeostasis

• Electrolyte imbalance (Hyperkalaemia)

• Medical vs. Surgical

  • Definitive surgical correction is usually required BUT medical stabilisation is essential before

What exactly is septic peritonitis? What are the three different classifications?

Peritonitis resulting from an identifiable source of intraperitoneal infection, typically bacterial in origin and most commonly a result of leakage of the GI tract

Classifications:

• Primary - spontaneous (ex: cats with FIP)

• Secondary - leakage of bacteria (foreign body caused)

• Tertiary - recurrence (worse prognosis)

How would one diagnose septic peritonitis?

• Haematology

  • Neutrophilia to neutropaenia

• Biochemistry

• Lactate - good indicator for how bad septic shock is

• A-POCUS

MOST EFFECTIVE

• Abdominal effusion

  • Cytology

    • intracellular bacteria

    • Degenerated neutrophils / toxic changes; will be pus-y

  • Peripheral glucose to abdominal

    • Difference of ≥ 38 mg/dl (2.1 mmol/L)

    • If glucose in abdomen is LOWER than glucose in blood, suggests septic peritonitis

  • Abdominal lactate to peripheral

    • > 2.5 mmol/L

    • If lactate in fluid is HIGHER than lactate in blood, suggests septic peritonitis

How would one then manage septic peritonitis?

NEEDS TO BE QUICK, CAN’T WAIT

• Broad spectrum antibiotics

• Fluid resuscitation - some cases may not be responsive due to septic shock causing vasodilation

• Control hypotension

  • Vasopressors?

• Infection source control !

  • Broad spectrum antibiotics

  • Ex-Lap

  • Peritoneal Lavage

  • Abdominal drain

Essentially, treat the infection and find the source ASAP

Further describe bile peritonitis… what can cause it? Why is it so damaging?

Is the leakage of bile into the peritoneal cavity. Caused by:

• Gall bladder rupture after trauma

  • 7-10 days post incident, so NEED TO KEEP AN EYE ON PATIENTS FOR THIS

• Post-hepatic Biliary tract obstruction (gallbladder stones)

Further causes damage by:

• Chemical/irritant effect on peritoneum

• Severe inflammation

• Coagulopathies (Vit K dependent) due to close association with the liver

How would one diagnose bile peritonitis?

Patient will be icteric

• Hyperbilirubinaemia

• Abdominal effusion 

  • TBil_effusion > TBil_plasma (>2:1)

  • Bilirubin crystals

• Abdominal cytology

  • Extracellular pigment

  • Rule out intracellular bacteria and concomitant sepsis

  • +/- culture and sensitivity

How would one manage bile peritonitis?

IS AN EMERGENCY

• Emergency

  • Fluid resuscitation/Shock

  • Vitamin K/FFP if coagulopathy

• Surgical

  • Ex-Lap

    • Resolution of the source

  • Peritoneal lavage

  • Abdominal drain

RANDOM TRAUMA NOW

What is traumatic pancreatitis, and what is unique about this in comparison to the other traumatic injuries in this lecture?

Can be damaged either DIRECTLY or INDIRECTLY

• Is very sensitive to hemorrhages or hypovolemia; can become inflamed even if uninjured

Potential causes:

• Subcapsular hematomas

• Ischemia to pancreas

Causes the leakage of pancreatic enzymes, which can be dangerous to surrounding tissue

• Autodigestion

• Acute pancreatitis

VERY COMMON IN CATS

What happens during a diaphragmatic hernia? What can it cause, and how can you determine a potential hernia on physical exam?

• Commonly secondary to blunt trauma

• Varying severity of dyspnoea

• Organs herniated:

  • Liver, stomach, small intestine, omentum, spleen

• Physical exam

  • Borborygmi on thoracic auscultation to dull/absent lung sounds

  • ”tucked in” abdomen

Diagnosis and management of diaphragmatic hernia?

• Diagnosis

  • POCUS is diagnostic in 93% of cases

  • Radiographs 

    • Presence of abdominal organs in the chest cavity

    • Loss of visualisation of the diaphragm

• Management

  • Surgery +/- chest drain