This summary focuses on the intensive care management of COVID-19 patients
- Non Invasive Ventilation and High Flow Nasal Cannula used in between 1/3rd and 2/3rd of patients in China.
- Human laboratory data suggests that NIV does not generate Aerosols.
- NIV and HFNC should be reserved for MILD ARDS patients
- Fluid management – COVID-19 patients might have Hypovolemia due to anorexia, vomiting, diarrhoea
- Early detection of Myocardial involvement by measurement of troponin and beta-natriuretic peptide and ECHOcardiogrpahy, and early use of Vasopressors and inotropes are recommended.
- Lower Mortality observed in those treated with Systemic Steroids – Methylprednisolone but benefits are unproven, and risk benefit ratio uncertain
Key – Management of Acute Respiratory Failure and Maintenance of Hemodynamics
Increase need for bed capacity, infrastructure and supplies, staff management
Intro – COVID 19 – 3rd coronavirus infection in 2 decades.
SARS, MERS, COVID 19
Epidemiology (comparison report)
- infected population of COVID 19 – 1 million as of 2nd April 2020
- Case Fatality Rate of COVID 19 – 5.2%
- Infected population of SARS – 8096
- Case fatality of SARS – 9.6%
- Infected population of MERS – 2494
- Case Fatality of MERS – 34.4%
Case fatality varies with region, with health care systems and do not account for undiagnosed patients with mild disease.
(In a large report 49% of all 2087 critically ill patients with COVID-19 in China Died, Small single ICU studies found mortality rates of 62% in Wuhan China, and 52% in Washington DC, USA – But these figures did not account for many who were still in the ICU.)
WHO-China study of COVID 19
- 1 % – Critical (Respiratory failure, shock, MOD)
- 8% – Severe (Dyspnoea, RR >= 30 breaths per min, O2 saturation <= 93%, PaO2/FiO2 < 300 mmHg, Lung Infiltrate > 50% within 24-48 hours)
Features of Critically ill COVID 19 Patients – Older age, With Comorbidities – HTN, Diabetes, CVD, Chronic Lung Disease, Cancer)
Median Time between Onset of Symptoms and Development of Pneumonia – 5 DAYS
Median Time between Onset of Symptoms and Severe Pneumonia and ICU admission – 7 – 12 DAYS
CXR Findings of COVID-19 patients.
- Ground Glass Opacities
MOST COMMON FINDING in ICU (60-70% of patients admitted to ICU)
- Acute Hypoxaemic Respiratory Failure
- Sometimes accompanied by severe Hypercapnia due to ARDS
Other Common Findings in ICU patients
- Shock – 30%
- Myocardial Dysfunction – 20-30%
- Acute Kidney Injury – 10-30%
- (Other study notes 44% of ICU patients present with Arrhythmia)
Note – Elderly Patients might develop Hypoxaemia without Respiratory Distress
- Severe Infections were observed to have
- Worse Respiratory failure
- Higher D-Dimer concentrations
- Higher CRP concentrations
- Lower Lymphocyte Counts
- Secondary Infections
- From Onset to Death – 2-8 Weeks
- From Onset to Clinical Recovery – 6-8 Weeks
WHO recommends – COVID 19 suspects in Patients with the following:
- Acute Respiratory Illness
- Travel History or Residence in a location reporting community transmission
- Contact with person confirmed or Probable COVID 19 Case in last 14 days before symptom onset
- Patients with Severe Acute Respiratory Illness who require hospitalisation without an alternative Diagnosis that explains the clinical presentation
Recommendations for ICU practitioners
- Have a high index of suspicion for COVID-19
- Low threshold for diagnostic testing for any patient with Severe acute respiratory infection
Basis of Diagnosis
- RT – PCR assay for SARS-CoV-2
- WHO Recommends – Sample from LOWER Respiratory Tract Such as Sputum and Endotracheal aspirates. (Procedure generates aerosols and should be performed with strict airborne precautions)
- Bronchoscopy should be generally avoided to minimise exposure of health care workers (inspite of its diagnostic yield of bronchoalveolar lavage)
- Sensitivity of RT-PCR for COVID-19 is Unknown.
- Repeated sampling might be required for Negative Initial tests for suspicious patients.
Management of Acute Respiratory Failure
- Non Invasive Ventilation and High Flow Nasal Cannula were used in between 1/3rd and 2/3rd of patients in China.
- NIV may be associated with Nosocomial transmission of SARS, however Human laboratory data suggests that NIV does not generate Aerosols.
- NIV and HFNC should be reserved for MILD ARDS patients
- Use of Single Rooms
- Intubation of COVID – 19 patients – risk of viral transmission to health care workers and Intubation drills are crucial.
- PPE – Personal protective equipment should be used.
- Reduce number of assistants.
- Minimise Bag mask ventilation due to risk of generating aerosols
- Viral filters can be placed between exhalation valve and mask.
- Rapid Sequence induction with Muscle relaxants will reduce coughing.
- End Tidal CO2 detection + Observe chest res eshould be used to confirm endotracheal tube placement.
- Use of Closed Suctioning systems post intubation will reduce aerosolisation.
- Avoid Ventilator induced lung injury while facilitating gas exchange via protective ventilation
- Prone Positioning should be applied ( associated with reduced mortality)
- ECMO is reserved for Most Severe of ARDS.
- Fluid management – COVID-19 patients might have Hypovolemia due to anorexia, vomiting, diarrhoea – Fluid management according to pre-load responsiveness such as passive leg raise test, given the high incidence of myocardial dysfunction in COVID-19 – due to high affinity of virus to ACE2 membrane bound receptor on host cells, expressed in the Lungs, Heart and others.
- A De-resuscitative fluid strategy – Early detection of Myocardial involvement by measurement of troponin and beta-natriuretic peptide and ECHOcardiogrpahy, and early use of Vasopressors and inotropes are recommended.
- Most COVID-19 patients were given Empirical Broad Spectrum Antibiotics and many Oseltamivir (due to difficulty and time required for diagnosis)
- Co-infections are also noted in studies, eg – Influenza
- Lower Mortality observed in those treated with Systemic Steroids – Methylprednisolone (Disclaimer – Observational study, small sample size and possible confounders)
- Immunosuppression – Due to Cytokine storm observed, Hyperinflammation and increased ferritin concentrations.
- Although Systemic corticosteroids and Immunosuppression benefits are unproven, studies show they have no impact on mortality, but possible harms – AVN, Psychosis, Diabetes, Delayed viral clearance.
- V Immunoglobulin
- Convalescent Plasma
Prevention of Infection
- WHO recommends PPE for health care workers providing direct care to patients with COVID-19 – Medical Masks, Gowns, Gloves, Eye protection, Face Shields.
- For aerosol generating procedures (tracheal intubation, NIV, Tracheostomy, CPR, Bag mask ventilation, Bronchoscopy) – Masks should be N95, FFP2 equivalent respirators and gowns and aprons – fluid resistant.