04/13/20- Monday
Pulmonary Embolism:
Obstruction of the pulmonary blood flow due to a blood clot. 70% arise from deep vein in the legs and the majority of the rest come from pelvis veins.
Risk factors: Virchow triad
1) Hypercoagulability (Protein C, S deficiency, etc).
2) Stasis (immobilization, prolonged sitting).
3) Vessel wall injury (trauma, infection).
Signs/Symptoms:
1) Dyspnea (MC symptom)
2) Pleuritic chest pain
3) Tachycardia
4) Tachypnea
5) Hypoxia
6) Hemoptysis
7) If there is a massive PE, pt can present with more severe symptoms such as hypotension or pulseless electrical activity.
Physical examination:
1) Homan sign for DVT (dorsiflexion of the foot gives you calf pain) which can unreliable.
2) More sensitive leg swelling >2cm and erythema
3) Lung exam is usually normal
Diagnosis:
1) ECG– sinus tachycardia (most common)
most specific for PE (S1Q3T3)
2) ABG– initially you can see respiratory alkalosis (due to hyperventilation) + hypoxemia. With massive PE you will eventually see respiratory acidosis.
3) D-dimer: works well to exclude DVT/PE but can have many false positive.
4) CXR: often normal in PE, however:
Hamptons Hump – peripheral dome shaped dense opacification
Westermark Sign – wedge shaped area of lung oligemia
These are classic but rare findings in PE.
Hamptons Hump Westermark Sign
5) Spiral CT angiography– best initial test confirm the presence of PE in most patients.
6) V/Q scan: used mostly in pts when CT scan can’t be performed and the patient is unable to receive contrast (for example pregnancy or those pts with increased creatinine). A tracer is injected into a vein in your arm. The tracer maps blood flow (perfusion) and compares it with the airflow to your lungs (ventilation)
7) Pulmonary angiography– Not usually performed but its ordered if high suspicion and negative CT or VQ scan.
8) Venous Doppler ultrasound for lower extremities: to rule out DVT.
9) Echocardiogram
Based on Wells criteria, our patient received a score of 4 which indicates PE is unlikely.
Treatment:
Hemodynamically stable: Anticoagulation as first line therapy in most patients. For example you can do heparin and bridge to PO warfarin or you can use a NOAC drug ( dabigatran, rivaroxaban, apixaban or edoxaban). You can also use Xarelto (PO) can also be used without bridging therapy.
IVC filter is indicated in stable pts when:
1) Anticoagulation is contraindicated (recent bleeding)
2) Anticoagulation is unsuccessful
3) RV dysfunction is seen on echocardiogram (next embolus even if small can be fatal)
Hemodynamically unstable: in those pts with right sided failure or severe PE we can do thrombolysis. If thrombolysis is contraindicated then we can do thrombectomy (interventional procedure of removing a blood clot (thrombus) from a blood vessel).
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04/14/20 Tuesday
According to an online survey conducted in end of March, 33% of an international panel of physicians reported personally prescribing hydroxychloroquine and 41% reported prescribing azithromycin for COVID-19 and almost all of them believed their patients were improving drastically.
There are currently a few studies that are being conducted right now, but one of the earliest ones was a study done in France.
They recruited 80 patients who tested positive for COVID-19 and had no contraindication to neither hydroxychloroquine nor azithromycin. All 80 patients received a combination of 200 mg of oral hydroxychloroquine sulfate, three times per day for ten days combined with azithromycin (500 mg on Day 1 followed by 250 mg per day for the next four days). The average age for these patients was 52 years old and 57.5% of these patients had a least one chronic condition. These patients were treated every day for 10 days and adverse effects associated with hydroxychloroquine and azithromycin were rare and minor.
Based on their results, 65/80 patients had a favorable outcome and were discharged from their unit. Only 15% of the patients required oxygen therapy during their stay and 3 patients were transferred to ICU which later 2 of them improved and made full recoveries. They reported only one death which was an 84-year-old man who died of pneumonia.
After treatment, a nasopharyngeal viral load tested by PCR was performed on each patient. On day 7, 83% of patients were negative of COVID-19 and on day 8, 93% of patients were negative. After day 10 only two patients only were still presumably contagious while the rest were negative.
Researchers In this study concluded that this combo of drugs is indicated only on those who have moderate infections at an early enough stage to avoid progression to a serious and irreversible condition. Their results also suggested that combination of hydroxychloroquine with azithromycin was more efficient than just doing hydroxychloroquine or azithromycin alone.
Researchers did recommend for routine EKG in patients who take both azithromycin and hydroxychloroquine because of possible risks of QT prolongation and other heart related issues. Although researchers here didn’t report any major adverse effects, Hydroxychloroquine, and azithromycin each carry the warning of QT prolongation and can be associated with an increased risk of cardiac death when used in a broader population.
Source:
Gautret, Philippe et al. “Clinical and microbiological effect of a combination of hydroxychloroquine and azithromycin in 80 COVID-19 patients with at least a six-day follow up: A pilot observational study.” Travel medicine and infectious disease, 101663. 11 Apr. 2020, doi:10.1016/j.tmaid.2020.101663
However, another randomized control study did not agree with the study done by the french. In this new study, participating patients received hydroxychloroquine (600 mg/day for 10 days) and azithromycin (500 mg on day 1, then 250 mg days 2-5) (higher dose than the previous study). The study group included 7 men and 4 women with a mean age of 58.7 years (range, 20-77 years); 8 had significant comorbidities associated with poor outcomes (ie, obesity in 2, solid cancer in 3, hematological cancer in 2, and HIV infection in 1). Ten of the eleven patients had fever and received oxygen via nasal cannula.
Within 5 days, one patient died and two were transferred to the ICU. Nasopharyngeal swabs remained positive for SARS-CoV-2 RNA in 8 of 10 patients at days 5-6 after treatment initiation.
In this study, researchers reported no evidence of rapid antiviral clearance or clinical benefit with combination of hydroxychloroquine and azithromycin in patients with severe COVID-19 infection and also they noted an increased 30-day risk of cardiovascular mortality, chest pain/angina, and heart failure was observed with the addition of azithromycin to hydroxychloroquine.
Source:
Author links open overlay panelJ.M.MolinaacC.DelaugerrebdJ.Le GoffbdB.Mela-LimaaD.PonscarmeaL.GoldwirteN.de Castroa
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Remdesivir is a broad-spectrum antiviral agent. It was synthesized and developed as a treatment for Ebola virus infection. In-vitro studies showed that remdesivir can inhibit coronaviruses such as SARS-CoV and MERS-CoV replication.
Remdesivir works by mimicking one of the genetic elements that the COVID-19 virus, known as SARS-CoV-2, uses to make more copies of itself. This blocks the virus from copying its genome, jamming up the viral copy machine.
According to NIH, a study using remdesivir to treat monkeys with COVID-19 proved to be efficient and reduce damage to the lungs. The study involved 2 groups. One group of monkeys received remdesivir while the other were not treated. Scientists infected both groups with SARS-CoV-2 and all participating monkeys had tested positive for COVID-19. Twelve hours later the treatment group received a dose of remdesivir intravenously, and then received a daily intravenous booster dose thereafter for the next six days.
Twelve hours after the initial treatment, they examined all animals and found that the group of monkeys that received treatment with remdesivir were significantly in better health than the untreated group, a trend that continued during the seven-day study.
They report that one of the six treated animals showed mild breathing difficulty, whereas all six of the untreated animals showed rapid and difficult breathing. The amount of virus found in the lungs was significantly lower in the treatment group compared to the untreated group, and SARS-CoV-2 caused less damage to the lungs in treated animals than in untreated animals.
Article
- Williamson, et al. Clinical benefit of remdesivir in rhesus macaques infected with SARS-CoV-2(link is external).
There is speculation from general population that ACEi or ARBs may increase COVID-19 severity. However, according to the American Heart Association, they recommend to continue taking these medication for HF as they found no correlation between COVID-19 severity and these medications.
Currently no specific treatment for COVID-19 is approved for FDA but reports from China have shows that the use of corticosteroids has shown some benefit in helping with the management of symptoms.
There is also speculation that high doses of IV vitamin C can also help with treatment. When it comes to prevention, there is no evidence that taking vitamin C will help prevent infection related with COVID-19. While standard doses of vitamin C are generally harmless, taking high doses can cause a number of side effects such as cramps, N/V and kidney stones. A study is underway in China to determine if this treatment is useful for patients with severe COVID-19; results are expected in the fall but right now high doses of IV vitamin C are not recommended.
Source: https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
https://www.health.harvard.edu/diseases-and-conditions/treatments-for-covid-19
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