Before attempting to wean the patient from the ventilator, confirm with the physician that the patient is ready. This entails:
- Curing or stabilizing the illness that mandated ventilation
- Preparing the patient emotionally (including professional counseling, if necessary)
- Providing physical or speech therapy to strengthen the neck and chest muscles used for breathing
Once this has occurred, the first step is a spontaneous breathing test so the patient can practice breathing, as well as to gauge lung strength. This can be done by setting the ventilator to CPAP mode and allowing the patient to breathe spontaneously without support.
An alternate option is through a setup called a T-tube trial. For this method, the patient is disconnected from the ventilator and allowed to breathe from a humidified air/oxygen source without any other ventilatory support.
Assuming the T-tube test proves effective, the patient may be permitted to use one of the following two ventilator-weaning methods.
Synchronized intermittent mandatory ventilation (SIMV)
SIMV allows the patient to take spontaneous breaths between mandatory machine breaths. Weaning is done by decreasing the mandatory breaths over time, which would require the patient to increase spontaneous breathing. Confer with the physician about this ventilator weaning method and patient safety.
Pressure supported ventilation (PSV)
This method allows the patient to control the rate and volume of each breath taken. Spontaneous breaths are supported by a set level of pressure to help initially open the lungs and lower the work of breathing.
Some physicians, instead of gradual weaning, do a spontaneous breathing test on the patient. If the patient is deemed ready, the ventilator tubes are removed.
This is effective for patients who are fully recovered from illness, young patients and short-term patients. It does not work for long-term ventilated patients or the elderly. In some cases, the ventilator will need to be reinserted, which can strain the health of more vulnerable patients.
Ventilator weaning should be done carefully. It is better, for example, for an anxious or weak patient to be given time to adjust. To increase the likelihood of success, make sure the patient is emotionally stable, well nourished and strong enough to cope with the transition.