Signs and Symptoms (February 2017)
Research:
AIR: Respiratory
For a Review Article
- How has reading the article changed your practice?
- What information had you believed in previously that were debunked by reading this article?
- What new information did you learn from reading this article?
- What are current areas of uncertainty on this topic that can be potential areas for research?
For an Original Research Article
- What are some strengths of the study?
- What are the limitations?
- What are the main outcomes of the study?
- Does reading this article change your practice? If so, how?
14 comments
Considering I’m sitting at home right now, with fevers and myalgias, I read the Abraham Flu article with great interest.
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A short and focused review on diagnosis, treatment, and prevention of flu and their efficacy. Check it out.
Influenza
Reminder to us: when we treat a patient with influenza, ask about elderly family members and small children at home, these may be the folks that benefit the most from treatment. I honestly don’t prescribe Tamiflu unless I am admitting the patient, the reduction in symptoms by 12 hours does not seem worth the cost, side effects, chance that a patient will buy this medication and not their HTN meds, etc. Also, these drug company studies in particular are notorious for failing to report null data, I suspect the efficacy of this medication is actually worse.
We don’t offer flu shots, should we? How much would it cost? Would it be worth it during terrible flu seasons?
Hinson et al.
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I personally was not aware that there was so much recent literature that questioned the old adage of contrast induced nephropathy. But this study summarizes those and adds to them very well.
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Nevertheless, without a RCT, it’s hard to say if nephroprotective strategies clinicians used to choose whether to give contrast or fluids resulted in the low risk of complications. Despite best efforts to adjust for these efforts, there might still be confounding factors one does not foresee.
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Time for a multi-centered RCT!
Hinson, et al.
I love this article, it fits what we know by practice, that if you have to get the CT scan & you hydrate the patient in advance with IV fluids, the risk of nephrotoxicity is PROBABLY really low.
One problem is that this is single center Hopkins, you can imagine that there are protocols in place mandating IV fluids before CT and probably forcing the ordering physician to think three times before ordering IV dye in diabetics, elderly, marginally increased creatinine, etc. Does this apply elsewhere?
Questions only a randomized trial can answer:
what is the safe Creatinine or GFR cut-off?
are diabetics and elderly patients at higher risk?
how much hydration in advance of CT scan is needed?
how much does IV contrast really improve CT accuracy? is it time to do away with it for everything except CT angiogram?
why can’t someone invent IV contrast with ZERO nephrotoxicity?
Review:
How has reading the article changed your practice?
Not much – test with PCR if result would change mgmt., Tamiflu not great, only for really sick/admitted people
What information had you believed in previously that were debunked by reading this article?
I didn’t know Tamiflu helps with transmission rate (although NNT is 33, not great)
What new information did you learn from reading this article?
see above.
What are current areas of uncertainty on this topic that can be potential areas for research?
efficacy of antiviral therapy in preventing complication – no great evidence but level B recommendations – kinda weird.
Original research:
What are some strengths of the study?
Very large study, academic ED, fairly broad inclusion criteria, great comparison groups and analysis of available data.
What are the limitations?
retrospective observational. biased in that mostly admitted (sicker) patients included.
What are the main outcomes of the study?
IV contrast for people with Cr <4 may not infer risk of contrast-induced renal injury or long term consequences
Does reading this article change your practice? If so, how?
somewhat – reassured that risk may be lower than suspected but still bound by institutional policies for renal function and contrast studies (at BMC, Cr needs to be lower than 1.7, I'm told by radiology)
Abraham et al.
1. How has reading the article changed your practice?
It hasn’t
2. What information had you believed in previously that were debunked by reading this article?
None
3. What new information did you learn from reading this article?
Influenza vaccination efficacy is between 40% and 80%. I thought it was higher than that.
4. What are current areas of uncertainty on this topic that can be potential areas for research?
More research on efficacy of Tamiflu and what the window for treatment is.
Hinson et al.
1. What are some strengths of the study? I like the “Importance” section of the introduction. Very informative.
2. What are the limitations?
Propensity score matching not as rigorous as RCT.
3. What are the main outcomes of the study?
Incidence of acute kidney injury
4. Does reading this article change your practice? If so, how?
No
Abraham (Influenza article)
How has reading the article changed your practice?
Not very much – reinforces for me the superiority of PCR over rapid antigen testing. It also helped me to review the very (?overly) broad populations that the CDC recommends treatment for.
What information had you believed in previously that were debunked by reading this article?
I did not know that chemoprophylaxis was used for preventing influenza.
What new information did you learn from reading this article?
I learned that the vaccine is only ~60% effective at preventing influenza
What are current areas of uncertainty on this topic that can be potential areas for research?
This article did not specifically address the tension between what the CDC recommends (very broad categories of patients to be treated with tamiflu) and what seems to be fairly bad evidence for its efficacy. For instance, this paper reports that one study showed decrease time of symptom duration, but that several studies did not show that tamiflu reduced hospitalization or prevented complications. There probably need to be more studies addressing these patient outcomes.
Hinson et al
1. I also enjoyed reading the “importance” section to learn where the fear of contrast-induced AKI comes from, and found it interesting that serum Cr levels fluctuate with non-con CTs as well
2. Study was retrospective, used propensity score matching to compensate for any differences in test ordering based on initial Cr but RCT would be more robust
3. Contrast media administration is not associated with an increased incidence of acute kidney injury
4. Not really – I will still get the CT if clinically indicated, and probably still give IVF if pt has an elevated Cr!
Also, apart from the very relevant topic, I read the article with great interest because I know all of the authors of the study!
Abraham et al.
1. Honestly, it hasn’t – just came from MICU and pedi and people are generally practicing as recommended in this article
2. I thought it was interesting that administration of the live intranasal vaccine didn’t relate to asthma exacerbations
3. The NNT for disease transmission for oseltamivir is 33
4. Whether oseltamivir decreases complications of influenza
INFLUENZA
-Change practice? While I’ve prescribed tamiflu and have treated flu in the ED, I’ve never really thought about its prevention. Given the a/w morbidity/mortality, I should do a better a job of providing flu vaccination info and making sure pts are referred to their PCP (or just offer it given our patient population).
-Debunked info? I had previously thought that influenza was more prevalent in the adult population vs children (incorrect, 5-10% vs 20-30%, respectively)
-New info? I knew the RAD test did not have great sensitivity but was unaware how bad it was (40-80%), basically flipping a coin. Lesson – if it looks like the flu, just treat it. Also, no difference in high dose vs low dose tamiflu.
-Potential research? Would be interesting to see a study on the implementation of influenza vaccination in the ED and a/w findings. Would it decrease influenza associated ED visits and/or admissions? Along the same lines, the author notes that there’s a lack of quality evidence investigating morbidity/mortality benefits of the influenza vaccine.
#AKI #contrast
-Strengths? Large study with significant power; attempts to answers a significant question posing ED providers; attempted to control with CT non con vs CT enhanced vs non CT; good summary on prior (flawed) research
-Limitations? Retrospective observational approach. Study was not generalizable – all pts came from one center. Majority of pts in study admitted, thus AKI may have been overestimated. Did not have pts with Cr > 4. Bias present as pts with AKI less likely to get contrast and more likely to receive nephro-protective tx (ie, fluids).
-Outcomes? IV contrast was not a/w increased freq of AKI
-Change in practice? Given that most of the studies that led to current practice have significant limitations, this study continues to push forward the idea the IV contrast does not induce AKI. I think once the ethical challenges are overcome, we’re a few RCTs and metanalayses away from getting there but I do think we’ll get there soon….so right now, I’ll just hold on to radiology recs and cling to the idea that IV contrast causes AKI.
Contrast and AKI/CKD
1. Strengths: This is a large study that uses a lot of data- researchers were able to track participants over time which is useful when trying to establish and association between contrast use and CKD. I like the inclusion of a non-CT group for more robust controls.
2. Weakness: As mentioned by others- retrospective study. Although not statistically significant, it seems that patients that received contrast may have had better kidney function to begin with which begs the question of whether studies were being ordered with kidney function in mind.
3. Outcomes: Use of contrast not associated with a higher rate of AKI or incidence of CKD.
4. Change in practice: This does change the way I think about contrast- I thought using contrast put patients at a significantly higher risk for AKI/CKD based on how we talk about it our ED and protocols. I will also consider things like race, nephrotoxic meds, and comorbidities when weighing pros and cons.
Flu
1. Change in practice: I learned that the rapid flu has lower sensitivity. That being said, I usually don’t swab people who I wouldn’t normally treat. I think Meg brings up a good point about asking about family members at home given that that may change my decision to treat. NNT seems high for tamiflu- good to know going forward.
2. Debunked: I also though flu was more common in adults compared to children prior to reading this.
3. Learning points: More concrete guidelines relating to who to treat, sensitivity of rapid flu, vaccinating asthmatics
4. Future studies: Association between vaccinations and complications of flu especially in more vulnerable populations- co-morbidities, elderly, children, ect.