What are the causes, symptoms, diagnostic methods, and management strategies for splenic rupture relevant to the NAC OSCE in Canada?

Splenic Rupture: NAC OSCE Canada Guide

Causes

Splenic rupture occurs primarily from blunt abdominal trauma (most common), but can also happen spontaneously or from underlying pathology.

Traumatic Causes (Most Common)

• Blunt abdominal trauma: Motor vehicle collisions, falls, sports injuries, assault
• Penetrating trauma: Stab wounds, gunshot wounds to left torso or upper abdomen
• The spleen is the most commonly injured solid organ in blunt abdominal trauma 1

Spontaneous/Pathological Causes

• Infectious mononucleosis (EBV) - classic cause of atraumatic rupture 2
• Hematologic disorders (leukemia, lymphoma)
• Splenic infections/abscesses
• Malaria
• Coagulopathy or therapeutic anticoagulation
• Underlying splenic pathology (cysts, tumors)
• Iatrogenic causes (approximately 10% of cases) 3

Important caveat: Spontaneous ruptures can occur without any identifiable cause and affect significantly older patients (median age 62 years vs 44 years for traumatic) with much higher mortality (36% vs 0% at 4 weeks) 4

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Symptoms

Patients present with signs of intra-abdominal hemorrhage and shock, though delayed presentations can occur.

Acute Presentation

• Left upper quadrant pain (most common)
• Kehr's sign: Left shoulder pain from diaphragmatic irritation by blood
• Signs of hemorrhagic shock:
  • Hypotension (systolic BP < 90 mmHg)
  • Tachycardia
  • Cool, clammy skin with decreased capillary refill
  • Altered level of consciousness
  • Shortness of breath 1

Associated Findings

• Abdominal distension
• Peritoneal signs (guarding, rigidity)
• Left lower rib fractures (in trauma cases)
• Fever, malaise, chills (in infectious causes) 1

Delayed Splenic Rupture

Critical pitfall: Delayed rupture can occur from 5 days to 2 months after initial injury 5, 6. There may be an asymptomatic period between injury and hemorrhage manifestation. Risk factors include:

• Subcapsular hematoma
• Pseudocyst or pseudoaneurysm
• Higher injury grades 6

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Diagnosis

Your diagnostic approach must be based entirely on the patient's hemodynamic status - this is the critical decision point 1.

Hemodynamically Unstable Patients

Definition of instability 1:

• Admission systolic BP < 90 mmHg with skin vasoconstriction, altered consciousness, or shortness of breath
• OR systolic BP > 90 mmHg but requiring bolus infusions/transfusions and/or vasopressors
• OR base excess > -5 mmol/L
• OR shock index > 1
• OR transfusion requirement ≥ 4-6 units PRBCs within first 24 hours

Diagnostic approach:

1. E-FAST (Extended Focused Assessment with Sonography for Trauma) - rapid bedside ultrasound to detect free fluid (sensitivity 91%, specificity 96%) 1
2. Proceed directly to operating room if positive - do NOT delay for CT

Hemodynamically Stable or Stabilized Patients

CT scan with IV contrast is the gold standard (sensitivity and specificity 96-100%) 1

Key CT findings to report:

• Injury grade (AAST classification I-V)
• Presence of contrast blush (active bleeding - occurs in 17% of cases and predicts >60% failure of non-operative management) 1
• Pseudoaneurysm (PSA)
• Amount of free fluid/hemoperitoneum
• Associated injuries

Important limitation: CT can miss 42% of cases with no significant blood extravasation or injuries near the diaphragm 1

Laboratory Tests

• Serial hemoglobin/hematocrit - dropping levels indicate ongoing bleeding
• Base excess
• Coagulation studies
• Type and crossmatch

Follow-up Imaging

• Doppler ultrasound or contrast-enhanced ultrasound (CEUS) useful for evaluating vascular complications and follow-up 1
• CEUS is superior to B-mode ultrasound for grading splenic ruptures and influences therapeutic management 4

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Management

Management is algorithmically determined by hemodynamic stability, injury grade, and presence of contrast extravasation 1.

Hemodynamically Unstable Patients

→ Immediate operative management (splenectomy) 1

• Damage control surgery if needed
• Splenectomy is life-saving measure
• Partial splenic salvage is debated and generally not recommended in acute bleeding 1
• Do NOT attempt laparoscopic splenectomy in bleeding trauma patients 1

Hemodynamically Stable Patients

Non-Operative Management (NOM) Criteria 1

NOM should ONLY be attempted in centers with:

• Intensive care/high-dependency monitoring capability
• Serial clinical examination and laboratory monitoring
• Immediate access to interventional radiology
• Immediate access to operating room
• Blood products immediately available

NOM Protocol:

1. Bed rest for first 48-72 hours with close clinical and laboratory observation 1
2. Serial hemoglobin/hematocrit monitoring
3. Repeat CT if:
   • Moderate-severe lesions
   • Decreasing hematocrit
   • Vascular anomalies present
   • Underlying splenic pathology or coagulopathy
   • Neurologically impaired patients 1

Angioembolization (AG/AE)

Consider AG/AE for 1:

• Hemodynamically stable patients with contrast blush on CT
• Persistent hemorrhage signs despite stability
• Post-traumatic pseudoaneurysms

Important: 65% of NOM failures require surgery within 24 hours of admission 5

Indications to Convert to Operative Management

Proceed to splenectomy if 1:

• NOM with AG/AE fails
• Patient remains hemodynamically unstable
• Significant drop in hematocrit
• Continuous transfusion requirements
• Peritonitis develops
• Severe coexisting injuries requiring intervention

Post-Splenectomy/Angioembolization Care

Vaccination (CRITICAL - affects long-term mortality) 1

All patients MUST receive immunization against encapsulated bacteria:

• Streptococcus pneumoniae
• Haemophilus influenzae type B
• Neisseria meningitidis

Timing 1:

• Ideally ≥14 days after splenectomy (antibody response suboptimal before this)
• If discharging before 15 days, vaccinate BEFORE discharge to avoid missing vaccination
• Annual influenza vaccine for patients >6 months age

Overwhelming Post-Splenectomy Infection (OPSI) 1:

• Incidence: 0.5-2%
• Mortality: 30-70% (most deaths within 24 hours)
• Risk highest in first year but elevated for life
• Patients must seek immediate medical attention for any fever, malaise, chills
• Consider prophylactic antibiotics for at least 2 years post-splenectomy
• Malaria prophylaxis for travelers

Activity Restriction 1

• Minor injuries: 4-6 weeks restricted activity
• Moderate-severe injuries: 6 weeks to 2-4 months restricted activity
• Normal activity resumption safe after at least 6 weeks for moderate-severe injuries

Thromboprophylaxis 1

• Mechanical prophylaxis safe in all patients without contraindication
• LMWH prophylaxis should be started as soon as possible and is safe in selected patients with blunt splenic injury undergoing NOM (spleen trauma without ongoing bleeding is NOT an absolute contraindication)

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Key Pitfalls to Avoid

1. Never delay surgery for CT in unstable patients - E-FAST and straight to OR
2. Don't miss delayed rupture - can occur up to 2 months post-injury; educate patients on warning signs
3. Don't forget vaccinations - vaccinate before discharge if leaving <15 days post-splenectomy
4. Don't attempt NOM without proper resources - requires ICU monitoring, immediate IR/OR access, and blood products
5. Watch for contrast blush on CT - >60% will fail NOM and may need AG/AE
6. Remember spontaneous ruptures have 36% mortality vs 0% for traumatic at 4 weeks 4
7. 65% of NOM failures occur within 24 hours - maintain high vigilance early 5