So I'm going to go over two guidelines in less than 15 minutes. So I'll try to be very, very fast. You'll have all the slides and I will show you where the articles are published, so you can see them and read the extended documents. The first guideline I want to review is the new fever guidelines that came out late last year. The executive summary is the shortened version. The longer document is on the left. I was fortunate enough to be a panelist in this particular guideline. So just some general principles. So fever in the ICU is considered to be a temperature of at least 38.3. I think the key point is that not every febrile episode necessarily warrants an investigation for fever, even though, you know, we're not very good at that. The good history and physical should always dictate whether you need to rule out an infection and work the patient up, and so we should not be practicing this reflex, getting cultures on patients just because they have a fever. The fever guideline basically had 26 PICO questions. We used the GRADE methodology. This was an update of a 2008 IDSA and SCCM guideline. We made 12 recommendations and nine best practice statements. I'll caveat this by saying the majority of our recommendations were weak or conditional, and a few were best practice statements. So the first thing about measuring temperature, we preferred that central temperature monitoring devices be used when available. So whether you have a bladder catheter, esophageal balloon, thermistor, or PA catheter, and you're measuring core central temperature, that would be favored if you have those devices already in place versus not having those devices. For those without those devices, we suggest oral or rectal over other measurements, such as axillary or temporal. Again, these were weak recommendations based on very low-quality evidence. Giving antipyretics, we said avoid routine use, but if patient comfort is important, which I think in some patients, very high fevers make patients uncomfortable, then it's okay to reduce the temperature by giving an antipyretic in those situations. Imaging studies, certainly somebody with a fever in an ICU where pneumonia is very common, we recommended that a chest radiograph be obtained in those patients, and of course in patients that have undergone surgery, thoracic, abdominal, or pelvic, where you need to work up a patient and concern, we said a best practice statement that you should get a CT scan in collaboration with your surgical patient that you're working up for a fever, and for those patients who have a fever where you've done all the other diagnostic tasks, if the risk of transport is minimal, you can consider a PET-CT. We could not make a recommendation on whether a white cell scan was important to do in a patient where you can't seem to establish an etiology. Ultrasonography, we do a lot of this now. We put out a best practice statement that you should not be doing routine ultrasound in a patient just because they have a fever, but they have no abdominal signs. Again, back to history, physical dictating what tests we should do, but certainly in patients who have a fever in our ICU with recent abdominal surgery or a patient with abdominal symptoms, you're suspicious about a cause that's intra-abdominal. You should get a formal bedside diagnostic ultrasound. You will be sometimes surprised, like we all do, where you'll find a calculus cholecystitis, maybe gallstones, maybe liver or kidney abscesses, or a perforated bowel, or ascites, or appendicitis that you may not have otherwise picked up had you not done an ultrasound of the abdomen. The advantages, of course, is you don't need to be worried about radiation and concern for patient transport. Thoracic bedside ultrasound, also recommended if you have a patient that you're working up with a fever and concern for a pulmonary infection, a pleural effusion, or something that might give you a concern that there is a possibility of a lung infection and you need to rule out effusions, or you may need to tap the patient that may have a complicated pleural effusion, and pyema, and so forth. Getting an ultrasound is always good, and doing ultrasound-guided treatment. Blood cultures, very important. We put out a best practice statement that we should collect blood cultures from two sites, from a peripheral site and from a central venous catheter, if that's in place. We recommend that at least two lumens of the central venous catheter be obtained blood cultures from, and at least two sets with at least 60 cc's of blood taken in the two collection bottles. Sometimes we don't do this well. Only 5 or 10 cc's is dropped into the blood culture. These are all best practice statements on when and how we should get blood cultures. We do a lot of rapid molecular testing now. In a patient with a fever, unclear etiology, we suggest if you have them available, then you should use it, but always draw blood cultures as you send rapid molecular testing. We have this for fungus in the T2 Candida panel. We have this for bacterial panel as well. Until more evidence comes out, it is good to send over this test alongside your blood cultures. Urine culture, again, we put out a best practice statement that you should not be obtaining your urine specimens from an existing folic catheter that you might think might be the source. You want to take that urine catheter out that's old, put a new one in, and then send your UA. If the UA has white cells, then of course send the culture. It shouldn't be reflexive, just that urine culture with blood culture. No, it should be dictated by whether or not you're concerned about a urinary tract infection, and you're sending a urine sample, and the urine sample has white cells. Then you pursue a urine culture. It should not be an automatic to send a urine culture. Testing for viruses, again, we have all these fancy panels now since COVID and even before that. Best practice statement, if you are concerned with a viral infection, including SARS-CoV-2, of course you should be testing for COVID. In terms of biomarkers, PCT, CRP are more commonly used. If your suspicion for an infection with a fever is low, then getting a procalcitonin or CRP might be beneficial in those settings so that you could avoid using antibiotics maybe in those patients. But if your probability for suspicion for infection is already high, then the PCT or CRP doesn't really add in making that decision. You should never use PCT or CRP to make the decision on whether you're going to start antibiotics or not. Of course, in a sick patient in the ICU, regardless of the PCT marker, you are going to start antibiotics in a sick patient. The take-home messages from the fever guideline is that most of our recommendations were weak. Several were best practice statements, but that's still good because it's the best evidence that we have so far. But clearly, we need additional advancement in research in many areas, including diagnostic imaging and how to properly use biomarkers in our patients. That's the fever guideline.

fever guidelines

ICU patients

core temperature monitoring

antipyretics

biomarkers