What is one indicator that a patient may be upgraded to severe sepsis?

Significantly decreased urine output is a key indicator suggesting that a patient may be experiencing severe sepsis. In the context of sepsis, the body's response to infection can lead to systemic inflammatory responses that affect organ function. One of the potential consequences is a decline in renal function, which is often indicated by a reduction in urine output.

When a patient has significantly decreased urine output, it typically indicates that the kidneys are not effectively filtering waste due to decreased blood flow or direct injury related to the septic state. This decline in kidney function is serious and can be a sign that the patient is progressing towards severe sepsis, where multiple organ systems may be compromised.

In contrast, the other options provided do not indicate an increase in severity of sepsis. An increased platelet count would not typically signal serious complications associated with sepsis, while a stable mental status and normal breathing suggest that the patient may not be exhibiting the signs of systemic organ dysfunction associated with severe sepsis. Therefore, decreased urine output serves as an important clinical indicator of worsening sepsis and the need for urgent medical intervention.