COVID-19: Complications

00:08 COVID-19 Complications.

00:11 COVID-19 as we know, can be critical in 5% of all patients.

00:15 Such patients, typically demonstrate progression to, acute respiratory distress syndrome, hypotensive shock and multi-organ dysfunction.

00:23 The risk for these individuals largely is seen in those who are older age.

00:27 So, median age of the critically ill COVID-19 patients at least 60 years of age.

00:34 They also many times have co-morbidities such as, insulin dependent diabetes, pre-existing cardiovascular disease, hypertension, immunodeficiency, et cetera.

00:44 Refractory cases, meaning those patients, who wind up in intensive care unit for even longer than is typical, are most often seen in those who are men, who are older, who present with pre-existing anorexia and or don't have the typical fever.

01:00 So, it may be their immune response is largely to blame for their acute severity of illness.

01:07 Especially predictive, is an individual presenting to medical attention, with a peripheral oxygenation factor of less than 90% and even less than 93%in some studies.

01:21 Median time of onset, so, after initial presentation of the classic mild respiratory illness, which we know, most people suffer from with COVID-19.

01:30 After 9 to 10 days, these individuals have progressed to, shortness of breath, respiratory failure, which requires them to be transferred to the intensive care unit.

01:40 Their critical care needs of course are extensive, so respiratory support, basically, anything needed to support, multi-organ failure, septic shock and acute respiratory distress syndrome.

01:53 When looking at immediate causes of death, in critically ill COVID-19 patients.

01:59 It is most often septic shock and multi-organ failure and the secondary complications of those, that are the immediate causes of death.

02:08 Death due to acute respiratory distress syndrome, is less common, only because there are more modalities available, to try and support one's respiratory status.

02:18 So, what is to blame for these complications? What is to blame for the severity of critical COVID-19? It's typically going to be a combination of direct organ damage from infection by SARS Coronavirus II, as we we've talked about in the pathogenesis session, but also, the triggering of local inflammation and then cytokine storm, by indirect pathogenic mechanisms.

02:45 So, as the immune system organizes and reacts against, the SARS-Coronavirus II infection.

02:52 Widespread endothelial damage can occur, Typically, an endothelialitis with microangiopathy, which involves, the vascular beds of multiple organ systems, especially lungs, but also heart, kidneys, liver and intestines.

03:07 Neovascularization, this is if not unique to a, COVID-19 and SARS-Coronavirus II infection, it is certainly different than that which is seen in influenza, in that SARS-Coronavirus II produces pulmonary angiogenesis, during its infection or infectivity of the alveolar epithelium, causing then new blood vessels, which of course then be can become leaky and flood the alveoli due to the cytokine storm.

03:39 Disseminated intravascular coagulation (DIC), Again, is a secondary phenomenon from the endothelialitis, the inflammation and microangiopathy, which triggers in effect, multiple microinfarcts, of the endothelial cells themselves, triggering then a consumptive coagulopathy or (DIC), along with that, hypercoagulability and thrombosis, because again of the cytokines storm, one is both consuming and providing abnormalities, of the clotting factors leading to strokes to thrombosis, to pulmonary emboli and all the other complications, you could imagine.

04:20 And then atypical inflammatory response and autoimmune phenomena, also, can be driven, so, Guillain-Barré syndrome, certainly, a variety of gait disturbances and muscle weaknesses, as well as, an entity known as multi-system inflammatory syndrome, in children or MISC, which, is due to an autoimmune phenomena, triggered by SARS-Coronavirus II infection.

04:48 So, what if you look at the at the organs, what are the list of complications by organ system.

04:54 So, within the brain any anywhere from simple headache, although I would argue, a headache is never simple, but a headache all the abnormalities, with a sense of smell and therefore, sense of taste to anosmia dysgeusia and then nausea and vomiting and certainly, impaired consciousness and cognitive disarray, all are complications seen with the brain.

05:19 Within the lung where the type II pneumocyte, is the preferred target of SARS-Coronavirus II, followed by inflammatory response, one can get direct alveolar damage, but then also lymphocytes and macrophage infiltration in cytokine storm, which basically, floods the lungs.

05:34 The kidneys, patients can present with or develop acute renal failure, along with tubular necrosis and as well lymphocyte and immune system infiltration followed by glomerular injury.

05:48 The heart, absolutely can develop myocarditis.

05:51 So active inflammation of various myocardial tissues, along with leukocyte infiltration.

05:59 Spleen and lymph nodes this largely is due to accumulation of macrophages, but also, secondary lymphocytes in the spleen and lymph nodes, so, enlarged lymph nodes and enlarged splenic sequestration, followed by tissue disruption.

06:13 And then the liver of course, is a target, both a primary and a secondary target, for the inflammatory burst or cytokine storm, followed, potentially routine SARS-Coronavirus II infection, and those patients who have liver injury of course can develop steatosis.

06:31 So, what are then the actual illnesses that one can see, in a critical COVID-19.

06:40 So, a primary viral pneumonia as well as a secondary bacterial pneumonia, acute kidney injury, pulmonary thromboembolism, sepsis and septic shock, respiratory failure and acute respiratory syndrome and then cardiomyopathy.

06:56 So, as you could see the complications of critical COVID-19, are robust unfortunately they are quite severe and you can understand why an individual with critical COVID-19, will be at risk for such a high mortality rate, as has been seen so far in this pandemic.