Home CHEST Thought Leaders Hot Topics in CHEST March 2020

Hot Topics in CHEST March 2020

By: Viren Kaul, MD (@virenkaul)

Viren KaulEach month, we ask our Social Media Co-Editors of CHEST to weigh in on the hot topics in CHEST. It's March, so let's hear from one of our co-editors, Dr. Kaul, as he outlines his highlights. After reviewing the issue, be sure to share your hot list on our Facebook wall, tweet with the hashtag #journalCHEST, or discuss in the CHEST LinkedIn group.

Before I get into my favorite picks from the March issue of journal CHEST®, I’d like to highlight the resource page on the coronavirus (COVID-19), put together by the experts at the American College of Chest Physicians. Please visit the page here to review tips to prepare for COVID-19 and read the most recent reports, research, and statements on the topic. 

My three picks this month are from the realms of infectious diseases, physiology/critical care, and thromboembolic diseases.

Rate and Predictors of Bacteremia in Afebrile Community-Acquired Pneumonia 

After reading the recently released guidelines regarding management of community-acquired pneumonia, I found myself questioning the role of acquiring blood cultures for patients admitted with community-acquired pneumonia. Before reading on, leave me a comment in the section beneath this post, because I would love to know your practice pattern.

In this multinational cohort study, only 8.9% of the 2,116 patients who were febrile also had bacteremia. The rates were lower for patients with hypothermia and those who were afebrile. Patients with afebrile bacteremia were the ones who exhibited the highest 28-day mortality at a rate of 9.9%. 

How does this impact my practice? 

Relying solely on fever and the confusion, urea, respiratory rate, blood pressure, and age 65 years or older (CURB-65) score being elevated (yes, I left this part out of my summary, but I strongly suggest reading the study to find out why!) should not be the only triggers for acquiring blood cultures. Based on identified predictors in this study, I will make sure to obtain blood cultures if patients have a positive finding on pneumococcal urinary antigen testing, a high blood urea nitrogen level, and elevated C-reactive protein levels. 

Search for Optimal Oxygen Saturation Targets in Critically Ill Patients: Observational Data from Large ICU Databases

Oxygen is one of the oldest “therapies” delivered to patients. The question on what the “ideal” range of maintained saturations should be was investigated by the Oxygen-ICU and ICU-ROX trials. In this large retrospective study conducted on two electronic medical record databases, the authors report a U-shaped association between oxygen saturation and mortality, with higher mortality rates observed at both saturations below 94% and above 98%. When saturations were maintained between 94% and 98% for 80% of the time in an ICU, the mortality rate was nearly one-half as compared with when saturations were maintained between 94% and 98% only 40% of the time.

Why did I highlight this study?

Well, the equipoise remains, in my opinion. The stage is set for a large randomized study evaluating appropriate oxygenation targets in critically ill patients. Given the heterogeneity of pathology in this set of patients, I worry that we may never find the answer that can be applied in a broad manner. (This is because almost no other therapy, intervention, or target should be in medicine.) The signal of harm with levels above 98% is consistent enough. But further studies evaluating permissive hypoxia should be undertaken with caution. In addition, separating pathologies where saturations are below 94% may certainly be appropriate (eg, severe acute respiratory distress syndrome) or essential, and application of these findings should be individualized. 

Probability of hospital mortality vs median blood oxygen saturation

Catheter-directed thrombolysis (CDT) and ultrasonographic-assisted CDT (CDT-US) are increasing in popularity as an intervention for eligible patients with acute pulmonary embolism despite the lack of robust literature to support their use. The authors used the 2016 National Readmissions Database to evaluate their nationwide utilization and compare outcomes of systemic thrombolysis, CDT, and CDT-US. The major strengths of this study are the geographically diverse population included and use of appropriate procedure codes.

The study found that systemic thrombolysis was the most commonly employed modality in 2016 (62.1% patients). Twenty percent of CDT cases employed CDT-US. No differences were found in the clinical outcomes, including periprocedural bleeding, in-hospital mortality, and readmission rates between the groups of patients receiving CDT and CDT-US. The rate of intracranial hemorrhage was 0.6% with CDT—a finding similar to previously reported data.

Where I stand on this matter?

As a new attending physician, I’ve become increasingly cognizant of the financial toxicity of our decisions on our patients, the health-care system, and, eventually, on the community at large. Practice what we preach. Practice what we know. I’ll wait for further large-volume and/or randomized controlled trials before committing myself to recommending CDT-US over CDT. As of now, I do not believe that the ability to provide CDT-US as opposed to CDT places our patients at a clinical advantage.

Outcomes of CDT-ultrasound compared with CDT alone.