MDCalc Wars – The Rise of BISAP: Is Ranson Retiring?

Written by Eric Steinberg DO, MEHP
REBEL EM
Medical Category: Abdominal and Gastroinstestinal
Acute Pancreatitis, bisap score, Clinical Decision Tools, MDCalc, MDCalc Wars, Pancreatitis, pancreatitis diagnosis, pancreatitis management, pancreatitis mortality, pancreatitis severity scoring, ranson’s criteria

October 27, 2025

🗝️ Key Points

🧮 Ranson’s = Old School Precision — Accurate but slow; requires 48-hour data and multiple labs. Best for inpatient management.
⚡️ BISAP = Fast and Focused — 5 quick bedside variables predict mortality almost as well as Ranson’s—no 48-hour wait.
🏥 Think Location: BISAP for the ED or acute care; Ranson for the floor or ICU once full data roll in.
🧠 Performance Parity: Despite its simplicity, BISAP holds similar prognostic accuracy to Ranson’s.
🚑 Bottom Line: For early triage and risk stratification, BISAP wins speed without sacrificing accuracy.

🤕 Case

A 55-year-old man with a history of alcohol use disorder, gallstones, and hypertension arrives in the ED clutching his abdomen, describing pain that shoots straight through to his back. He’s nauseated, he’s vomited twice, and between groans, he mentions taking a thiazide diuretic — and possibly being bitten by his pet scorpion (because, of course he has one). His mental status is normal, heart rate 110, other vitals unremarkable. Lipase? 2,500. So now the question: how bad is this pancreatitis, — Ranson-level serious, or just a BISAP blip?

📌 Clinical Decision Rules

Predicting severity in acute pancreatitis matters — it guides where patients go, how closely we watch them, and how aggressively we manage fluids and complications. Two of the most commonly used tools are Ranson’s Criteria and the BISAP Score.

Ranson’s offers a comprehensive, data-rich assessment once labs and time points are available, while BISAP gives a fast, bedside estimate of mortality risk that’s perfect for the early phase of care.

🔗 Scoring Tools:
➡️ Ranson’s Criteria — Pancreatitis Mortality Prediction
➡️ BISAP Score — Early Mortality Risk Estimation

🎯 Quick Hits

💬 Case Resolution

In the ED, we ran the BISAP score — quick, painless, and reassuringly low. The patient was admitted for supportive care (and, hopefully, a scorpion relocation plan). Forty-eight hours later, the inpatient team broke out the Ranson criteria, confirming a mild course and no major complications. A few days of fluids, pain control, and bland diet later, he was home — pancreas (and scorpion) both intact.

🚨 Clinical Bottom Line

Ranson’s Criteria:

Best used when serial lab data are available to provide a comprehensive prognosis.
Ideal for inpatient management and guiding the intensity of ongoing care.

BISAP Score:

Designed for early, point-of-care mortality risk estimation using fewer variables than Ranson’s.
Most useful in the ED or acute care setting to help guide initial disposition and triage decisions

Post Peer Reviewed By: Marco Propersi, DO (Twitter/X: @Marco_Propersi), and Mark Ramzy, DO (X: @MRamzyDO)

🧭 Cheat Sheets

BISAP Score for Pancreatitis Mortality

Ranson's Criteria for Pancreatitis Mortality

👤 Author

Eric Steinberg

DO, MEHP

Content Director, MDCalc, Residency Director, Emergency Medicine St. Joseph's University Medical Center, Paterson, NJ

Meet The Team

🔎 Your Deep-Dive Starts Here

Cite this article as: Eric Steinberg DO, MEHP, "MDCalc Wars – The Rise of BISAP: Is Ranson Retiring?", REBEL EM blog, October 27, 2025. Available at: https://rebelem.com/mdcalc-wars-the-rise-of-bisap-is-ranson-retiring/.