# The Importance of Systemic Inflammatory Response Syndrome in Diagnosing Occult Infections: A Case Report

## TL;DR

This case report shows how SIRS criteria helped detect a hidden infection in a patient, despite ongoing debates about its reliability.

## Contribution

The case demonstrates SIRS's value in early sepsis detection, even as newer tools like qSOFA are considered.

## Key findings

- The patient met SIRS criteria and had occult MRSA bacteremia detected through an infectious workup.
- SIRS showed greater sensitivity in initial sepsis diagnosis compared to newer tools like qSOFA.
- Combining SIRS and qSOFA with awareness of their limitations is recommended for best sepsis screening.

## Abstract

Systemic inflammatory response syndrome (SIRS) criteria are among the several screening tools for sepsis. While SIRS has been widely utilized in clinical practice, its reliability and construct validity have come under scrutiny in recent years. Research has established that the quick Sequential Organ Failure Score (qSOFA) and Sequential Organ Failure Assessment (SOFA) criteria serve as better predictors of sepsis-related outcomes. We report a case of a patient who was admitted for diabetic ketoacidosis and atrial fibrillation. Despite being afebrile with stable white blood cell counts, he met SIRS criteria (tachycardic and tachypneic) on admission, which initiated an infectious workup. Subsequent investigations revealed multiple substernal and intramuscular abscesses along with costosternal osteomyelitis resulting in methicillin-resistant staphylococcus aureus (MRSA) bacteremia. The patient underwent surgical source control and recovered after a prolonged course of intravenous antibiotics. This study highlights the importance of timely detection of sepsis and the role of SIRS criteria as a reliable screening tool in this process. Notwithstanding the controversy around the credibility of the SIRS criteria, conceptualized nearly two decades ago, it has proven to have greater sensitivity in the initial diagnosis of sepsis in comparison to other available screening tools. Screening for sepsis using both qSOFA and SIRS criteria concurrently, with an understanding of their limitations, represents best practice.