The PIRO (predisposition, insult, response, organ dysfunction) model: toward a staging system for acute illness

Area of Science:

• Critical Care Medicine
• Clinical Staging Systems
• Patient Stratification

Background:

• Multimodal cancer therapy relies on staging systems (e.g., TNM) to identify patient subgroups for tailored treatments.
• Critically ill patients are heterogeneous, with varied responses and risks associated with multiple therapeutic options.

Purpose of the Study:

• To propose and explore the rationale for the PIRO (predisposition, insult, response, organ dysfunction) system as a template for staging acute illness.
• To address the challenges in creating a robust and clinically useful staging system for acute conditions.

Main Methods:

• Review of the rationale for illness stratification models in acute care.
• Summary of preliminary cohort studies evaluating the PIRO concept.
• Proposal of strategies for developing a comprehensive staging system.

Main Results:

• The PIRO system integrates pre-morbid susceptibility, the acute insult, host response, and organ dysfunction.
• Significant challenges exist, including disease complexity, lack of clear phenotypes, and confounding factors like therapy and socio-economic influences.

Conclusions:

• A valid and robust staging system for acute illness is essential for optimizing patient care and outcomes.
• Developing such a system, like PIRO, is a long-term, complex undertaking requiring extensive research and collaboration.