Intensive Care Management of COVID-19

Posted by

Salient Features:

This summary focuses on the intensive care management of COVID-19 patients

Management:

  • 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

Detailed Summary

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)

M/C Symptoms

  • Fever
  • Cough
  • Fatigue
  • Dyspnoea

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
  • Consolidation

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

Lab Findings

  • Severe Infections were observed to have
  1. Worse Respiratory failure
  2. Higher D-Dimer concentrations
  3. Higher CRP concentrations
  4. Lower Lymphocyte Counts
  5. Secondary Infections

Median time

  • From Onset to Death – 2-8 Weeks
  • From Onset to Clinical Recovery – 6-8 Weeks

Diagnosis

WHO recommends – COVID 19 suspects in Patients with the following:

  1. Acute Respiratory Illness
  2. Fever
  3. Travel History or Residence in a location reporting community transmission
  4. Contact with person confirmed or Probable COVID 19 Case in last 14 days before symptom onset
  5. 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.

Experimental Therapies

  • Remdesivir
  • Lopinavir-ritonavir
  • Chloroquine
  • Hydroxychloroquine
  • V Immunoglobulin
  • Convalescent Plasma
  • Tocilizumab
  • Favipiravir

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.

Reference Link : https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30161-2/fulltext

Leave a Reply

Your email address will not be published. Required fields are marked *