Table 2.
Factors affecting weaning in patients in PICU.
| Factors | Study data |
|---|---|
| Fluid status | Cumulative fluid balance (ins and outs) is not associated with ventilator weaning duration or extubation outcomes in critically ill children.10 Studies of children with multiorgan failure showed survival may be associated with less fluid overload in the setting of continuous renal replacement therapy and that children placed on extracorporeal life support for respiratory failure showed increased survival with fluid removal and return to dry body weight.2,3 |
| Sedative regimen | Choice of sedative regimen and sedation level can affect ventilator weaning and readiness for extubation. Excessive sedation may depress respiratory drive while inadequate sedation can lead to agitation and thrashing movements, which can result in trauma from the tracheal tube.2,9 Increased use of sedative drugs in the first 24 h of weaning predicts failure of extubation.2,9 Targeting a state behavioural scale score of 0, where a patient is awake and able to be calm helps optimise sedation level.11 |
| Pulmonary hypertension | Pulmonary hypertension affects patient oxygenation. Because oxygen therapy and mechanical ventilation are cornerstones of the management of pulmonary hypertension, hesitance to wean such support can significantly affect readiness for extubation especially when direct measures of pulmonary arterial pressure or pulmonary vascular resistance are unavailable.2,12 |
| Diaphragmatic function | Infants and young children have less well developed accessory respiratory muscles and weaker diaphragmatic function at baseline, which may relate to their longer weaning times.2,13 Significant diaphragm atrophy and a decreased diaphragmatic thickening fraction (DTF) measured by point-of-care ultrasound have been observed within 24 h of mechanical ventilation. DTF of <10% and the recovery of diaphragmatic thickness predicts successful weaning from mechanical ventilation.14,15 |
| Airway steroids | Using corticosteroids to prevent (or treat) postextubation stridor has not proven effective for neonates or children; however, there have been findings suggesting benefit particularly for high-risk children or neonates.16 Of note, multiple doses of corticosteroids begun 12–24 h before extubation do appear beneficial for adult patients with a high likelihood of postextubation stridor.16 |
| Disease reversibility and chronicity | Patients with rapidly reversible respiratory disease (like RSV bronchiolitis) as the cause of their respiratory failure and need for mechanical ventilation wean quicker and extubate faster than patients with slowly reversible disease (such as pneumonia, acute respiratory distress syndrome [ARDS]) or patients with chronic issues (such as genetic disorders/syndromes, chronic respiratory failure, chronic neuromuscular disease, chronic noninvasive ventilation, and prolonged steroid exposure).2,3,15,17 |
| Cardiac function | Patients requiring prolonged ventilation in cardiac intensive care units (CICUs) are more likely to suffer from severe cardiovascular dysfunction compared with patients in a general PICU.18 |
| Nutritional status | A study of ventilator-induced diaphragmatic atrophy in mechanically ventilated PICU patients found that optimal nutritional intake during mechanical ventilation averaged 54% and 53% of recommended calories and proteins. There may be an association between nutritional status and diaphragmatic atrophy and dysfunction in critically ill children who are mechanically ventilated.15 |