July 14, 2020 - a podcast by COVID19LST

On today's episode we discuss:

Climate:

— An opinion article by Swiss physicians titled “Is Clinical Effectiveness in the Eye of the Beholder?” warns against the implementation of treatments with unsound and incomplete evidence, arguing they may violate the principle of non-maleficence, or 'do no harm'.  Hydroxychloroquine as an example of a drug that was widely adopted based off minimal in-vitro studies and unscientific promotion in the media. There is now a consensus that it does not offer therapeutic benefit and may have caused unnecessary harm through dangerous QT prolongation and diminished supply for patients with autoimmune diseases. The authors suggest that until effective treatments are proven, we should rely on social distancing and ensuring scientific journals and researchers are held to a high standard.

Understanding the Pathology:

— A simulation model estimating the possible effect widespread use of remdesivir in South Africa - where the death rate is estimated at 85%-100% among patients who cannot obtain intensive care due to the lack of available ICU beds – predicted a reduction in COVID-19 mortality by 635 to 6,862 deaths (out of a projected 36,383 to 47,820 ICU patients as estimated by the South African National COVID-19 Epidemiology model (NCEM). These results suggest that remdesivir may reduce mortality indirectly by reducing the duration of illness and freeing up ICU beds

Management: 

— A case series of nine COVID-19 patients presenting with neurological symptoms discovered a common MRI finding of microbleeds in an unusual distribution (most notably the corpus callosum) suggesting a mechanism of damage to the endothelium of brain vessels (thrombotic microangiopathy) by SARS-CoV-2.

R&D DIAGNOSIS AND TREATMENT:

An interdisciplinary group from across the United States details the key factors that influence the Positive Predictive Value (PPV) and the Negative Predictive Value (NPV) of diagnostic testing for COVID-19, with the goal of enabling healthcare providers to better understand the implications of a positive or negative COVID-19 test result in the context of an unknown true prevalence of the disease in the population. Three key points include:

o For low disease prevalence, the sensitivity doesn't play a large role in the PPV or NPV; instead, the focus must be on having a very high specificity in order to achieve a clinically usable PPV.

o For high disease prevalence, neither the sensitivity nor the specificity has a major impact on the PPV; however, high sensitivity is needed to obtain a clinically relevant NPV, so the focus here must be identification of a test with very high sensitivity.

o In the situation where prevalence is neither low nor high, the sensitivity tends to influence the PPV and the specificity tends to influence the NPV, so increasing utility of a test in this situation can focus on improving either the sensitivity or specificity, or both.

---

Support this podcast: https://anchor.fm/covid19lst/support

Further episodes of The COVID-19 LST Report

Further podcasts by COVID19LST

Website of COVID19LST