Apply initial triage findings to visualize the "Harmless" course probability.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Initial screening in the ED for patients with acute pancreatitis (within first 30–60 minutes)
To identify "non-severe" patients who are highly unlikely to develop organ failure
To justify early ward admission and potential early oral intake in the "low-risk" subset
Clinical Objective
Unlike APACHE II or BISAP which seek to identify "sick" patients, HAPS was designed as a "rule-out" tool. It has a very high Negative Predictive Value (NPV) for severe disease.
Section 2
Formula & Logic
The 3 Clinical Criteria
Absence of Rebound Tenderness or Guarding (Clinical Exam)
Normal Haematocrit (Male < 43%, Female < 39.6%)
Normal Serum Creatinine (< 2 mg/dL or 177 μmol/L)
Scoring Logic
The score is binary. If ALL THREE criteria are met, the patient is classified as having "Harmless" Acute Pancreatitis.
The Negative Predictive Value (NPV)
HAPS Met (All 3)
98% NPV for Severe Acute Pancreatitis
HAPS Not Met
Requires full scoring (BISAP/APACHE)
Section 3
Pearls/Pitfalls
Why HAPS is the ED Favorite
HAPS requires only a physical exam and two basic lab tests (CBC and BMP). It can be "calculated" within minutes of a patient arriving in the triage bay, allowing for rapid decision-making before more complex biomarkers (like CRP or IL-6) are ever processed.
Validation and Triage
While it doesn't predict who *will* get sick perfectly, it identifies with 98% certainty who *won't* get sick. This allows the medical team to focus aggressive resuscitation resources on the high-risk subset from the very start.
Clinical Pearls
HAPS should be reassessed at 24 hours if the initial results were borderline
Haematocrit is a surrogate for hemoconcentration and Third-Spacing; maintaining a normal Hct is a sign of adequate baseline perfusion
The absence of guarding/rebound suggests the absence of widespread peripancreatic fluid/inflammation at the time of presentation
Section 4
Next Steps
Triage Recommendation
01
HAPS Met: Admission to a general ward; early low-fat oral diet as tolerated; routine fluid resuscitation.
02
HAPS Not Met: High-care or step-down admission; aggressive fluid monitoring; calculate BISAP and reconsider ICU needs.
Complementary Scoring
BISAP Score (Acute Pancreatitis)
APACHE II Score
Ranson Criteria
Section 5
Evidence Appraisal
The Foundational Score
The harmless acute pancreatitis score: a clinical algorithm for rapid initial stratification of patients with acute pancreatitis.
Lankisch PG et al. • Clinical Gastroenterology and Hepatology. 2009;7(6):702-5. Original derivation proving the high NPV.
Developed by Paul Georg Lankisch, a world-renowned expert in pancreatitis from Lüneburg, Germany. His vision was to simplify the "chaos" of initial ED triage by providing a common-sense checklist that any clinician could perform immediately.
