Severe COVID-19 commonly progresses to acute hypoxemic respiratory failure and may evolve into Acute Respiratory Distress Syndrome due to diffuse alveolar damage, pulmonary edema, inflammatory infiltrates, and ventilation-perfusion mismatch.

When non-invasive respiratory support fails, endotracheal intubation and invasive mechanical ventilation become lifesaving interventions. Management must be performed by trained personnel and preferably under supervision of an intensivist.

1. Indications for Intubation

Immediate intubation is recommended when ANY of the following occur:

Clinical Criteria

• Persistent SpO₂ < 90% despite maximal oxygen therapy

• Signs of severe respiratory fatigue

• Altered mental status (GCS < 13)

• Hemodynamic instability

• Cardiac arrest or peri-arrest

• Inability to protect airway

• Apnea or gasping breathing

Laboratory Criteria

• PaO₂ < 60 mmHg on FiO₂ ≥ 0.6

• PaO₂/FiO₂ ratio < 150

• Rising PaCO₂ with respiratory acidosis

• Severe metabolic acidosis requiring ventilatory compensation

2. Intubation Procedure (Rapid Sequence Intubation – RSI)

Preparation

• Full PPE (N95/FFP2, face shield, gown, gloves)

• Negative pressure room if available

• Pre-oxygenate 100% FiO₂ for 3–5 minutes

• Avoid bag-mask ventilation unless necessary

Medications

Typical regimen:

• Sedative: Etomidate / Ketamine / Propofol

• Paralytic: Rocuronium / Succinylcholine

Key Safety Measures

• Use video laryngoscopy when possible

• Inflate cuff immediately

• Attach HEPA filter before ventilation

• Confirm placement via waveform capnography

3. Mechanical Ventilation Strategy

COVID-19 ARDS requires lung-protective ventilation.

A. Ventilator Mode

Preferred initial mode:

• Volume Controlled Ventilation (VCV) OR

• Pressure Controlled Ventilation (PCV)

B. Lung Protective Ventilation Targets

Permissive Hypercapnia

Allowed if:

• pH ≥ 7.15–7.20

• Hemodynamics stable

• No raised intracranial pressure

Purpose: prevent ventilator-induced lung injury.

4. Positive End-Expiratory Pressure (PEEP)

PEEP prevents alveolar collapse and improves oxygenation.

General Approach

• Start 8–10 cmH₂O

• Gradually titrate based on oxygenation and compliance

• Avoid overdistension

Signs of Excess PEEP

• Hypotension

• Decreased lung compliance

• Increased plateau pressure

5. Prone Ventilation

Strongly recommended for moderate-severe ARDS.

Indication

PaO₂/FiO₂ < 150

Protocol

• 12–16 hours per day

• Experienced team required

Physiologic Benefits

• Improves V/Q matching

• Recruits dorsal lung regions

• Reduces ventilator-induced lung injury

• Improves survival

6. Sedation and Neuromuscular Blockade

Sedation Goals

• RASS −2 to −4 initially

• Prevent ventilator dyssynchrony

Preferred strategy:

• Analgesia-first sedation

• Non-benzodiazepines preferred

Neuromuscular Blockade

NOT routine — consider only if:

• Severe dyssynchrony

• Refractory hypoxemia

• Plateau pressure uncontrollable

Continuous infusion ≤ 48 hours preferred.

7. Ventilator Circuit Safety

To prevent aerosol spread:

• Avoid circuit disconnection

• Use closed suction systems

• Clamp ETT during transfers

• HEPA filter on expiratory limb

ROUTINE ICU CARE FOR INTUBATED PATIENTS

FAST HUGS BID PROTOCOL

A standardized checklist reduces mortality and complications.

F — Feeding (Nutrition)

Early enteral feeding within 24–48 hrs unless contraindicated.

Goals

• 25–30 kcal/kg/day

• Protein 1.2–2.0 g/kg/day

If NPO > 5–7 days

→ Consider parenteral nutrition

Prevents:

• Muscle wasting

• Immune suppression

• Delayed recovery

A — Analgesia

Pain causes ventilator dyssynchrony and increased oxygen demand.

Preferred:

• Opioid infusion ± adjuncts

• Use validated pain scale (CPOT)

Avoid unnecessary deep sedation.

S — Sedation

Daily sedation interruption recommended.

Goals:

• Light sedation when possible

• Prevent delirium

• Facilitate early weaning

Avoid benzodiazepines when possible.

T — Thromboembolism Prophylaxis

COVID-19 causes hypercoagulability.

All ICU patients should receive:

• Low molecular weight heparin (preferred)OR

• Unfractionated heparin

Adjust dose for renal failure.

H — Head Elevation

≥ 30 degrees

Prevents:

• Ventilator-associated pneumonia

• Aspiration

• Increased intracranial pressure

U — Ulcer Prophylaxis

Indicated for:

• Mechanical ventilation >48 hrs

• Coagulopathy

• Shock

Use:

• Proton pump inhibitor OR

• H2 blocker

Stop when risk resolves.

G — Glycemic Control

Target blood glucose:6–10 mmol/L (108–180 mg/dL)

Avoid:

• Hypoglycemia

• Hyperglycemia-related infection

S — Spontaneous Breathing Trial (SBT)

Daily assessment for ventilator weaning.

Criteria:

• Hemodynamically stable

• Adequate oxygenation

• Awake or lightly sedated

B — Bowel Regimen

Prevent ileus and constipation:

• Stool softeners

• Early enteral feeding

I — Indwelling Lines

Daily review necessity of:

• Central line

• Arterial line

• Foley catheter

Remove ASAP to prevent infection.

D — De-escalate Antibiotics

COVID-19 is viral — antibiotics only if bacterial infection suspected.

Daily reassessment required:

• Culture-guided therapy

• Stop early when possible

Weaning and Extubation Criteria

Patient ready when:

• SpO₂ ≥ 92% on FiO₂ ≤ 40%

• PEEP ≤ 8 cmH₂O

• Adequate cough

• Hemodynamically stable

• Successful spontaneous breathing trial

Key Complications to Monitor

• Ventilator-associated pneumonia

• Barotrauma

• Delirium

• Thrombosis

• ICU-acquired weaknesst