10.3 Additional Weaning Strategies

In Chapter 5, we explored several ventilation modes that enable patients to have spontaneous breaths and ensure a seamless transition from control ventilation to spontaneous supported ventilation. Depending on the available ventilator options and site protocols, we have discussed the following modes that can aid in facilitating the weaning process from mechanical ventilation: Mandatory Minute Ventilation (MMV), Automode, Adaptive Support Ventilation (ASV), Proportional Assist Ventilation (PAV) and Volume Support (VS). These ventilation modes offer valuable choices for tailoring the weaning approach to each patient’s needs, supporting a smoother transition towards independent breathing and eventual liberation from mechanical ventilation.

Automatic Tube Compensation (ATC)

In addition, it is worth mentioning another ventilation strategy available on some ventilators, Automatic Tube Compensation (ATC). This is a feature designed specifically to overcome resistance imposed by the endotracheal tube. ATC can be combined with all conventional ventilatory modes when resistance through the endotracheal tube is high. This seems to work especially in cases of difficult to wean patients who may not have an appropriate size artificial airway (airway too small).

When ATC is used, the ventilator monitors patient inspiratory flow, and based on flow pattern and requirements and size of artificial airway, pressure is increased during inspiration and decreased during expiration to overcome the resistance and decrease work of breathing. A percentage of support can be set on the ventilator from [latex]1\text{ - }100\%[/latex] compensation.

Tracheostomy for Weaning

Patients who face challenges with weaning from mechanical ventilation are often offered a tracheostomy tube instead of an endotracheal tube for various compelling reasons. This shift is motivated by a range of benefits, including enhanced comfort for the patient, reduced reliance on sedation, easier oral hygiene management, and the flexibility of being able to disconnect from ventilation temporarily and reconnect if necessary, all without requiring reintubation. The presence of a tracheostomy, allows weaning through Tracheostomy Mask Trials (TMT).

A TMT involves a carefully planned daily period during which ventilatory support is temporarily removed. This trial serves as a progressive step towards the patient’s independence in supporting their own breathing. Each day, the duration of ventilatory support removal can be gradually extended, allowing the patient’s respiratory function to strengthen until they can breathe independently without assistance. During TMT, oxygen and humidity is usually provided to ensure patient comfort.