COVID-19-associated respiratory failure: Difference between revisions
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==Differentiating COVID-19-associated respiratory failure from other Diseases== | ==Differentiating COVID-19-associated respiratory failure from other Diseases== | ||
The ARDS and subsequent respiratory failure caused by COVID-19 can be differentiated by other diseases through following factors <ref name="Li Ma p. ">{{cite journal | last=Li | first=Xu | last2=Ma | first2=Xiaochun | title=Acute respiratory failure in COVID-19: is it “typical” ARDS? | journal=Critical Care | publisher=Springer Science and Business Media LLC | volume=24 | issue=1 | date=2020-05-06 | issn=1364-8535 | doi=10.1186/s13054-020-02911-9 | page=}}</ref> | The ARDS and subsequent respiratory failure caused by COVID-19 can be differentiated by other diseases through following factors <ref name="Li Ma p.">{{cite journal | last=Li | first=Xu | last2=Ma | first2=Xiaochun | title=Acute respiratory failure in COVID-19: is it “typical” ARDS? | journal=Critical Care | publisher=Springer Science and Business Media LLC | volume=24 | issue=1 | date=2020-05-06 | issn=1364-8535 | doi=10.1186/s13054-020-02911-9 | page=}}</ref> | ||
* '''Timing of Onset :''' According to Berlin Criteria of ARDS , the onset must be within 1 week of clinical insult buy various reported onsets of COVID-19 related ARDS had mean onset time of 8-12 days from ARDS. It is therefore suggested that there should be caution against development of ARDS in COVID-19 patients with the course of more than week. | * '''Timing of Onset :''' According to Berlin Criteria of ARDS , the onset must be within 1 week of clinical insult buy various reported onsets of COVID-19 related ARDS had mean onset time of 8-12 days from ARDS. It is therefore suggested that there should be caution against development of ARDS in COVID-19 patients with the course of more than week. | ||
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!COVID-Related ARDS leading to respiratory failure | !COVID-Related ARDS leading to respiratory failure | ||
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|ARDS is divided into three stages based on oxygenation index (PaO2/FiO2) on PEEP ≥ 5 cmH2O:<ref name="American Medical Association (AMA) p. ">{{cite journal | title=Acute Respiratory Distress Syndrome | journal=JAMA | publisher=American Medical Association (AMA) | volume=307 | issue=23 | date=2012-06-20 | issn=0098-7484 | doi=10.1001/jama.2012.5669 | page=}}</ref> | |ARDS is divided into three stages based on oxygenation index (PaO2/FiO2) on PEEP ≥ 5 cmH2O:<ref name="American Medical Association (AMA) p.">{{cite journal | title=Acute Respiratory Distress Syndrome | journal=JAMA | publisher=American Medical Association (AMA) | volume=307 | issue=23 | date=2012-06-20 | issn=0098-7484 | doi=10.1001/jama.2012.5669 | page=}}</ref> | ||
* Mild (200 mmHg < PaO2/FiO2 ≤ 300 mmHg) | * Mild (200 mmHg < PaO2/FiO2 ≤ 300 mmHg) | ||
Revision as of 09:01, 2 July 2020
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
Synonyms and keywords:
Overview
The most devastating complication of SARS-CoV-2 is acute hypoxaemic respiratory failure which requires mechanical ventilation. There can be multiple causes that can lead to acute hypoxemic respiratory failure ranging from pulmonary edema , vascular occlusion, ventilation/perfusion mismatch and haemoglobinopathies. The most important pathology is usually acute respiratory distress syndrome ( ARDS) that eventually leads to hypoxaemic respiratory failure in patients that are not maintaining oxygen saturation. The difference between COVID related ARDS and the usual ARDS is the injury site which is mainly the respiratory system involving the alveolar epithelial cells. Usually the clinical symptoms don't correlate with the severity of imaging and laboratory findings. Lung compliance maybe normal in some patients. The patients that progress towards acute respiratory failure are usually managed by mechanical intubation with tidal volume target of 6mL/kg PBW.
Historical Perspective
- In December 2019, an outbreak of coronavirus disease (COVID-19) broke out in Wuhan,China.
- COVID-19 was a clustering pneumonia like illness which affected patients that rapidly developed ARDS.
- ARDS was one of the most important cause of hospital and ICU admission due to COVID.
- Many autopsies studies reported ARDS to be the cause of death in patients dying due to respiratory complications of COVID
Classification
Respiratory failure can be classified in two types. The respiratory failure that primarily occurs in COVID-19 patients is type 1 respiratory failure which is hypoxemic respiratory failure.
| Hypoxemic Respiratory Failure (Type 1) | Hypercapnic Respiratory Failure (Type 2) |
|---|---|
| PaO2 is lower than 60 mmHg | PaCO2 is greater than 50 mmHg |
| Most common form of respiratory failure | Mostly seen in COPD patients |
| Can involve any condition that involves fluid filling or collapse of alveolar units
Proposed respiratory failure that occurs in COVID-19 patients that experience respiratory distress |
Other Etiologies may include
|
Pathophysiology
- After the infection of the SARS-CoV-2 virus, Type II pneumocytes release inflammatory cytokines that recruit macrophages.
- Macrophages further release cytokines that cause vasodilation and allow more neutrophils and macrophages to come to the site of injury.
- Fluid starts accumulating into the alveolus which leads to dilution of surfactant.
- SARS-CoV propagates within type II cells and releases a large number of viral particles. The type II pneumocytes undergo apoptosis and die. This results in a self-replicating pulmonary toxin as the released viral particles infect type II cells in adjacent units.
- Normally, type II cells are the precursor cells for type I cells.
- This postulated sequence of events has been further supported by the murine model of influenza pneumonia.
- The pathological result of SARS and COVID-19 is diffuse alveolar damage in which there is the development of fibrin hyaline membranes and formation of a few multinucleated giant cells. This aberrant wound healing may lead to further scarring and fibrosis which is more severe than other forms of ARDS.
- Recovery will require a vigorous innate and acquired immune response and epithelial regeneration.
- Elderly individuals are particularly susceptible because of their diminished immune response and inability to regenerate damaged epithelium quickly. Due to reduced mucociliary clearance, it may allow the virus to spread to the gas exchange units of the lung more readily.
- The respiratory failure resulting as a complication of ARDS is due to the result of the acute systemic inflammatory response which is caused by the direct or indirect insults to the lungs.
- In the early exudative stage of ARDS, there occurs the development of diffuse alveolar damage with the destruction of epithelial cells and endothelial cells.
- There are two mechanisms which can lead ARDS or any other pathology to respiratory failure in COVID-19
| V/Q Mismatch | Development of Shunt |
|---|---|
|
|
Causes
Airspace filling in acute hypoxemic respiratory failure (AHRF) is due to
- Elevated alveolar capillary hydrostatic pressure
- Increased alveolar capillary permeability such as COVID-19 predisposing to acute respiratory distress syndrome (ARDS)
- Hemorrhage into alveoli or inflammatory exudates
Differentiating COVID-19-associated respiratory failure from other Diseases
The ARDS and subsequent respiratory failure caused by COVID-19 can be differentiated by other diseases through following factors [1]
- Timing of Onset : According to Berlin Criteria of ARDS , the onset must be within 1 week of clinical insult buy various reported onsets of COVID-19 related ARDS had mean onset time of 8-12 days from ARDS. It is therefore suggested that there should be caution against development of ARDS in COVID-19 patients with the course of more than week.
- Respiratory system compliance : Not all the cases of acute respiratory failure caused by COVID-19 were ARDS.The typical CT findings of the COVID-19 affected patient showed bilateral ground-glass shadow with a peripheral lung distribution. Although there were consolidation and exudation, this was not the typical "ARDS picture".Lung compliance might be relatively normal in some COVID-19-related ARDS patients who met ARDS Berlin criteria which is inconsistent with ARDS caused by other factors.In addition, the lung compliance was relatively high in some COVID-19-related ARDS patients, which was inconsistent with the severity of hypoxemia.
- Severity of Hypoxemia :
| Berlin Criteria Of ARDS leading to respiratory failure | COVID-Related ARDS leading to respiratory failure |
|---|---|
ARDS is divided into three stages based on oxygenation index (PaO2/FiO2) on PEEP ≥ 5 cmH2O:[2]
|
COVID-19-related ARDS was divided into three categories based on oxygenation index (PaO2/FiO2) on PEEP ≥ 5 cmH2O [3]
|
Epidemiology and Demographics
The incidence/prevalence of [disease name] is approximately [number range] per 100,000 individuals worldwide.
OR
In [year], the incidence/prevalence of [disease name] was estimated to be [number range] cases per 100,000 individuals worldwide.
OR
In [year], the incidence of [disease name] is approximately [number range] per 100,000 individuals with a case-fatality rate of [number range]%.
Patients of all age groups may develop [disease name].
OR
The incidence of [disease name] increases with age; the median age at diagnosis is [#] years.
OR
[Disease name] commonly affects individuals younger than/older than [number of years] years of age.
OR
[Chronic disease name] is usually first diagnosed among [age group].
OR
[Acute disease name] commonly affects [age group].
There is no racial predilection to [disease name].
OR
[Disease name] usually affects individuals of the [race 1] race. [Race 2] individuals are less likely to develop [disease name].
[Disease name] affects men and women equally.
OR
[Gender 1] are more commonly affected by [disease name] than [gender 2]. The [gender 1] to [gender 2] ratio is approximately [number > 1] to 1.
The majority of [disease name] cases are reported in [geographical region].
OR
[Disease name] is a common/rare disease that tends to affect [patient population 1] and [patient population 2].
Risk Factors
There are no established risk factors for [disease name].
OR
The most potent risk factor in the development of [disease name] is [risk factor 1]. Other risk factors include [risk factor 2], [risk factor 3], and [risk factor 4].
OR
Common risk factors in the development of [disease name] include [risk factor 1], [risk factor 2], [risk factor 3], and [risk factor 4].
OR
Common risk factors in the development of [disease name] may be occupational, environmental, genetic, and viral.
Screening
There is insufficient evidence to recommend routine screening for [disease/malignancy].
OR
According to the [guideline name], screening for [disease name] is not recommended.
OR
According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].
Natural History, Complications, and Prognosis
If left untreated, [#]% of patients with [disease name] may progress to develop [manifestation 1], [manifestation 2], and [manifestation 3].
OR
Common complications of [disease name] include [complication 1], [complication 2], and [complication 3].
OR
Prognosis is generally excellent/good/poor, and the 1/5/10-year mortality/survival rate of patients with [disease name] is approximately [#]%.
Diagnosis
Diagnostic Study of Choice
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
OR
The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
OR
The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
OR
There are no established criteria for the diagnosis of [disease name].
History and Symptoms
The majority of patients with [disease name] are asymptomatic.
OR
The hallmark of [disease name] is [finding]. A positive history of [finding 1] and [finding 2] is suggestive of [disease name]. The most common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3]. Common symptoms of [disease] include [symptom 1], [symptom 2], and [symptom 3]. Less common symptoms of [disease name] include [symptom 1], [symptom 2], and [symptom 3].
Physical Examination
Patients with [disease name] usually appear [general appearance]. Physical examination of patients with [disease name] is usually remarkable for [finding 1], [finding 2], and [finding 3].
OR
Common physical examination findings of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
The presence of [finding(s)] on physical examination is diagnostic of [disease name].
OR
The presence of [finding(s)] on physical examination is highly suggestive of [disease name].
Laboratory Findings
An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].
OR
Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].
OR
[Test] is usually normal among patients with [disease name].
OR
Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].
OR
There are no diagnostic laboratory findings associated with [disease name].
Electrocardiogram
There are no ECG findings associated with [disease name].
OR
An ECG may be helpful in the diagnosis of [disease name]. Findings on an ECG suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
X-ray
There are no x-ray findings associated with [disease name].
OR
An x-ray may be helpful in the diagnosis of [disease name]. Findings on an x-ray suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no x-ray findings associated with [disease name]. However, an x-ray may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with [disease name].
OR
Echocardiography/ultrasound may be helpful in the diagnosis of [disease name]. Findings on an echocardiography/ultrasound suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no echocardiography/ultrasound findings associated with [disease name]. However, an echocardiography/ultrasound may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
CT scan
There are no CT scan findings associated with [disease name].
OR
[Location] CT scan may be helpful in the diagnosis of [disease name]. Findings on CT scan suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no CT scan findings associated with [disease name]. However, a CT scan may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
MRI
There are no MRI findings associated with [disease name].
OR
[Location] MRI may be helpful in the diagnosis of [disease name]. Findings on MRI suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
There are no MRI findings associated with [disease name]. However, a MRI may be helpful in the diagnosis of complications of [disease name], which include [complication 1], [complication 2], and [complication 3].
Other Imaging Findings
There are no other imaging findings associated with [disease name].
OR
[Imaging modality] may be helpful in the diagnosis of [disease name]. Findings on an [imaging modality] suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
Other Diagnostic Studies
There are no other diagnostic studies associated with [disease name].
OR
[Diagnostic study] may be helpful in the diagnosis of [disease name]. Findings suggestive of/diagnostic of [disease name] include [finding 1], [finding 2], and [finding 3].
OR
Other diagnostic studies for [disease name] include [diagnostic study 1], which demonstrates [finding 1], [finding 2], and [finding 3], and [diagnostic study 2], which demonstrates [finding 1], [finding 2], and [finding 3].
Treatment
Medical Therapy
There is no treatment for [disease name]; the mainstay of therapy is supportive care.
OR
Supportive therapy for [disease name] includes [therapy 1], [therapy 2], and [therapy 3].
OR
The majority of cases of [disease name] are self-limited and require only supportive care.
OR
[Disease name] is a medical emergency and requires prompt treatment.
OR
The mainstay of treatment for [disease name] is [therapy].
OR
The optimal therapy for [malignancy name] depends on the stage at diagnosis.
OR
[Therapy] is recommended among all patients who develop [disease name].
OR
Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
OR
Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
OR
Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
OR
Patients with [disease subclass 1] are treated with [therapy 1], whereas patients with [disease subclass 2] are treated with [therapy 2].
Surgery
Surgical intervention is not recommended for the management of [disease name].
OR
Surgery is not the first-line treatment option for patients with [disease name]. Surgery is usually reserved for patients with either [indication 1], [indication 2], and [indication 3]
OR
The mainstay of treatment for [disease name] is medical therapy. Surgery is usually reserved for patients with either [indication 1], [indication 2], and/or [indication 3].
OR
The feasibility of surgery depends on the stage of [malignancy] at diagnosis.
OR
Surgery is the mainstay of treatment for [disease or malignancy].
Primary Prevention
There are no established measures for the primary prevention of [disease name].
OR
There are no available vaccines against [disease name].
OR
Effective measures for the primary prevention of [disease name] include [measure1], [measure2], and [measure3].
OR
[Vaccine name] vaccine is recommended for [patient population] to prevent [disease name]. Other primary prevention strategies include [strategy 1], [strategy 2], and [strategy 3].
Secondary Prevention
There are no established measures for the secondary prevention of [disease name].
OR
Effective measures for the secondary prevention of [disease name] include [strategy 1], [strategy 2], and [strategy 3].
References
- ↑ Li, Xu; Ma, Xiaochun (2020-05-06). "Acute respiratory failure in COVID-19: is it "typical" ARDS?". Critical Care. Springer Science and Business Media LLC. 24 (1). doi:10.1186/s13054-020-02911-9. ISSN 1364-8535.
- ↑ "Acute Respiratory Distress Syndrome". JAMA. American Medical Association (AMA). 307 (23). 2012-06-20. doi:10.1001/jama.2012.5669. ISSN 0098-7484.
- ↑ Phua, Jason; Weng, Li; Ling, Lowell; Egi, Moritoki; Lim, Chae-Man; Divatia, Jigeeshu Vasishtha; Shrestha, Babu Raja; Arabi, Yaseen M; Ng, Jensen; Gomersall, Charles D; Nishimura, Masaji; Koh, Younsuck; Du, Bin (2020). "Intensive care management of coronavirus disease 2019 (COVID-19): challenges and recommendations". The Lancet Respiratory Medicine. Elsevier BV. 8 (5): 506–517. doi:10.1016/s2213-2600(20)30161-2. ISSN 2213-2600.