Clinical prediction scores predicting weaning failure from invasive mechanical ventilation: Role and limitations

Table 3 Causes of weaning failure

Respiratory factors[29-32]	Increased airway resistance - bronchospasm, excessive secretions, ET block, kinks, blood in ET Decrease compliance - pulmonary edema, fibrosis, atelectasis, acute respiratory distress syndrome (ARDS) Ventilator induced lung injury - ventilator associated pneumonia, pneumothorax, hemothorax Increased work of breathing - dynamic hyperinflation, patient - ventilator dyssynchrony/asynchrony
Cardiac factors[33-35]	Pre-existing cardiovascular disorders – ischemic heart disease, valvular heart disease, pericardial diseases; stress cardiomyopathy; unresolved primary systemic disease
Neuromuscular factors[36-42]	Primary neuromuscular disorders
	Myasthenia gravis
	Guillain-Barre syndrome
	Myopathies
	Peripheral neuropathies
	Secondary causes
	Ongoing sedatives
	On neuromuscular paralyzing agents
	Critical illness neuromyopathies
	Ventilator induced diaphragmatic dysfunction
	Long term corticosteroid use
Neuropsychological[43-45]	ICU delirium; anxiety
Metabolic & endocrine[41]	Dyselectrolytemias; hypokalaemia, hypomagnesemia, hypophosphatemia; hypo/hypernatremias; hypo/hyperglycaemia; hypothyroidism; hypoadrenalism; long-term corticosteroid use
Nutrition[46,47]	Pre-existing malnutrition; underweight; Inadequate calorie intake; refeeding syndrome

ARDS: Acute respiratory distress syndrome; ET: Endotracheal tube; ICU: Intensive care unit.