The optimum timing to wean invasive ventilation for patients with AECOPD or COPD with pulmonary infection

Figures & data

Table 1 Indications for non-invasive ventilation (NIV) and invasive ventilation (IV)

NIV indications	IV indications
Clinical manifestations	Cardiac/respiratory arrest
Moderate to severe dyspnea	Non-respiratory organ failure
Respiratory rate over 25 breaths/min	Severe upper gastrointestinal bleeding
Obvious use of accessory muscles	Hemodynamic instability
Paradoxical breathing	Unstable cardiac arrhythmia
Gas-exchange abnormalities	Facial surgery
PaCO2 exceeding 45 mmHg	Facial trauma or deformity
pH below 7.35	Upper airway obstruction
PaO2/FiO2 below 250 mmHg	Inability to cooperate
	Airway protection
	Clear of secretions and saliva
	A high risk of aspiration

Abbreviations: FiO₂, fraction of inspired oxygen; PaO₂, partial pressure of oxygen in arterial blood; PaCO₂, partial pressure of carbon dioxide in arterial blood.

Table 2 Complications associated with intubation, tracheotomy, or ventilation

Common complications of intubation and tracheotomy
Airway complications
Laryngeal edema
Tracheal mucosal trauma
Contamination of the lower respiratory tract
Loss of humidifying function of the upper airway
Common complications of mechanical ventilation
Mechanical complications
Accidental disconnection
Leaks in the ventilator circuit
Loss of electrical power
Loss of gas pressure
Pulmonary complications
ventilator-induced lung injury
Barotrauma
Oxygen toxicity
Atelectasis
Nosocomial pneumonia
Inflammation
Auto-PeeP
Asynchrony
Acid–base complications
Respiratory acidosis
Respiratory alkalosis
Cardiovascular complications
Reduced venous return
Reduced cardiac output
Hypotension
Gastrointestinal and nutritional complications
Gastrointestinal bleeding
Malnutrition
Renal complications
Reduced urine output
Increase in antidiuretic hormone (ADH) and decrease in atrial natriuretic peptide (ANP)
Neuromuscular complications
Sleep deprivation
Increased intracranial pressure
Critical illness weakness

Abbreviation: PEEP, positive end-expiratory pressure.

Table 3 Assessment of weaning parameters

Clinical assessment	1. Adequate cough
	2. Absence of excessive tracheobronchial secretion
	3. Resolution of disease acute phase for which the patient was intubated
Objective measurement	4. Clinical stability
	Stable cardiovascular status (ie, fc ≤140 beats/min), systolic BP 90–160 mmHg, no or minimal vasopressors
	Stable metabolic status
	5. Adequate oxygenation
	SaO2 >90% on FiO2 0.4 (or PaO2/FiO2 ≥150 mmHg)
	PEEP ≤8 cm H2O
	6. Adequate pulmonary function
	fR ≤35 breaths/min
	MIP ≤−20 to −25 cm H2O
	VT >5 mL/kg
	fR/VT <105 breaths/min/L
	No significant respiratory acidosis
	7. Adequate mentation
	8. No sedation or adequate mentation on sedation (or stable neurologic patient)

Abbreviations: BP, blood pressure; fc, frequency of cardiotach; FiO₂, fraction of inspired oxygen; f_R, frequency of respiration; MIP, maximal inspiratory pressure; PaO₂, partial pressure of oxygen in arterial blood; PEEP, positive end-expiratory pressure; SaO₂, arterial oxygen saturation; V_T, tidal volume.

Table 4 Standard of the PIC window

Indexes	Evaluation
Imaging change	Significantly decreased radiographic infiltrations
ventilator settings	10–12 beats/min for SIMV
	10–12 cm H2O for PSV
Body temperature	≤38°C
Leukocyte count	<10,000/mm^3 or 2,000/mm^3 less than before
Sputum quantity	Significantly reduced
Lightening of sputum color	Changed to white
Decreased density of sputum	<II (second level)

Abbreviations: PIC, pulmonary infection control; PSV, pressure support ventilation; SIMV, synchronized intermittent mandatory ventilation.