What is the role of the Forrest scale in managing bleeding peptic ulcers?

The Role of the Forrest Scale in Managing Bleeding Peptic Ulcers

The Forrest classification is a critical risk stratification tool that guides endoscopic treatment decisions for bleeding peptic ulcers, predicts rebleeding risk, and helps determine the timing and necessity of interventions to reduce mortality and morbidity. 1

Understanding the Forrest Classification

The Forrest classification categorizes peptic ulcer bleeding based on endoscopic findings:

• Forrest I: Active bleeding

  • Ia: Spurting arterial bleeding
  • Ib: Oozing bleeding

• Forrest II: Signs of recent bleeding

  • IIa: Non-bleeding visible vessel
  • IIb: Adherent clot
  • IIc: Flat pigmented spot

• Forrest III: Clean ulcer base (no signs of bleeding)

Clinical Application and Treatment Recommendations

Endoscopic Treatment Indications

• Mandatory endoscopic hemostasis is recommended for high-risk stigmata 1:

  • Forrest Ia (spurting ulcer)
  • Forrest Ib (oozing ulcer)
  • Forrest IIa (non-bleeding visible vessel)

• Selective approach for intermediate risk:

  • For Forrest IIb (adherent clot), non-aggressive clot irrigation rather than mechanical dislodgment is recommended 1

• No endoscopic treatment needed for low-risk stigmata:

  • Forrest IIc (flat pigmented spot)
  • Forrest III (clean ulcer base)

Rebleeding Risk Prediction

The Forrest classification effectively predicts rebleeding risk, particularly for gastric ulcers 2:

• Highest rebleeding rates in Forrest Ia (59%)
• Similar odds ratios for rebleeding among Forrest Ib-IIc ulcers
• Lowest rebleeding rates in Forrest III

Recommended Treatment Approach

1. Dual modality endoscopic treatment is superior to monotherapy for high-risk lesions (Forrest Ia, Ib, IIa) 1

   • Mechanical therapy with epinephrine injection shows best outcomes
   • Reduces rebleeding probability (OR 0.19) and need for surgery (OR 0.10)

2. Pharmacological management 1, 3:

   • Start PPI therapy as soon as possible
   • After successful endoscopic hemostasis, administer high-dose PPI (80 mg bolus followed by 8 mg/h continuous infusion for 72 hours)
   • Continue PPI for 6-8 weeks following endoscopic treatment

Enhancing the Forrest Classification

Integration with Other Risk Scores

The World Journal of Emergency Surgery recommends using the Forrest classification alongside:

• Blatchford score
• Clinical judgment 1

This combined approach allows for better risk stratification:

• Very low risk—safe for outpatient management
• Low risk—need for admission and early endoscopy (≤24h)
• High risk—need for resuscitation and urgent endoscopy (≤12h)

Advanced Techniques

Doppler probe-guided assessment improves risk stratification beyond visual Forrest classification 1, 4:

• Detects blood flow in visible vessels
• Significantly reduces 30-day rebleeding rates compared to standard visual assessment
• Number needed to treat: 7 1
• Associated with significant reduction in recurrence of bleeding, surgical intervention, and bleeding-associated mortality 4

Special Considerations

Forrest IIc Lesions and Rockall Score

For Forrest IIc lesions at second-look endoscopy, the Rockall score can identify patients at higher risk of rebleeding 5:

• Patients with Rockall scores ≥6 have significantly higher rebleeding rates (24.3% vs 4.3%)
• Consider more aggressive monitoring or intervention in these high-risk patients

Simplified Classification Proposal

Research suggests the Forrest classification could potentially be simplified into three risk categories 2:

• High risk (Forrest Ia)
• Increased risk (Forrest Ib-IIc)
• Low risk (Forrest III)

However, this simplified approach requires further validation before implementation.

Pitfalls and Caveats

1. Context matters: The Forrest classification is validated for peptic ulcer bleeding but may not apply to post-endoscopic resection ulcers 6

2. Interobserver variability: Visual assessment can vary between endoscopists

3. Limitations in duodenal ulcers: The Forrest classification is more reliable for gastric ulcers than duodenal ulcers 2

4. Monotherapy risks: Using endoscopic monotherapy is associated with higher mortality risk compared to dual therapy 7

5. Dynamic nature: Bleeding stigmata can evolve over time, potentially requiring reassessment

By using the Forrest classification as part of a comprehensive approach to bleeding peptic ulcers, clinicians can make evidence-based decisions that significantly reduce rebleeding rates, the need for surgery, and mortality.