Hello Mrs. Passarelli, with your description, I think the infectious shock or septic shock is the most possible cause. Since your husband is 85 years old, other causes can't be excluded: respiratory failure, heart failure, kidney failure. Can you get updates in time from his doctor? Keep communicating with his medical team, it helps you understand his condition. Sometimes we can only rely on the medical team, and then pray. Let's pray for your husband.