Weaning From Mechanical Ventilation After Pediatric Cardiac Surgery

Different methods have been used to predict the optimum time to make the weaning decision. These methods include, success of spontaneous breathing trials (SBTs), counting respiratory rate, observation of work of breathing, and many other calculated indices such as hypoxic index, oxygenation index, stress index, oxygen reserve index, dynamic compliance, and rapid shallow breathing index (RSBI). However, some of these indices may be misleading and not precise.

Pressure support ventilation (PSV) has been widely used in the performance of a spontaneous breathing trial because it can compensate to some extent for the additional work of breathing imposed by the endotracheal tube and the breathing circuit. However, it is difficult to recognize the exact pressure support to overcome the tubing resistance during the weaning process till extubating.

The ventilator modality of automatic tube compensation (ATC) can provide variable pressure supports during the weaning process to overcome any change in the resistance of the breathing circuit, endotracheal tube, and airways. ATC is effective in overcoming the work of breathing caused by airway resistance to allow successful weaning process and extubating.

Several studies have investigated the effectiveness of ATC and PS for ventilatory weaning in adult patients, with conflicting results. Fewer studies have focused on the pediatric population, and even fewer have specifically examined patients who have undergone cardiac surgery. Therefore, there is a need for further research to determine the most effective weaning mode for this patient population.

Inclusion criteria

• Age 2-10years.
• Both sex.
• after fulfilling weaning criteria
• being pain free (observational pain/discomfort scale < 4). the weaning criteria; which include: low mandatory ventilator rate [6-8] or less; fraction of inspired oxygen (FIO2) ≤ 40; level of positive end expiratory pressure (PEEP) [3-5 cmH2O] guided by pressure/volume loop; reversal of the cause of postoperative mechanical ventilation; oxygenation index (OI) (mean air way pressure × FIO2/PaO2) < 5; dynamic compliance (Cdyn) > 1 ml/ cmH2O/kg

Exclusion criteria

• Duration of mechanical ventilation is more than 48 hours
• Patients on high inotropic support (unstable hemodynamics)
• Patients with disturbed conscious level
• Patients with palliative cardiac shunting procedures (e.g., BT shunt, Glenn shunt).