Spontaneous breathing trial
Encyclopedia
A goal for most patients on mechanical ventilation
is to be weaned from the ventilator. The weaning process is highly dependent on the patient's pathology, but the final common pathway to ventilator independence always includes at least one trial of spontaneous breathing. Trials of spontaneous breathing have been shown to accurately predict the success of spontaneous breathing.
(Tobin Index) of less than or equal to 105. The RSBI ("Riz-bee") is simply the ratio of respiratory frequency in respirations per minute to tidal volume in liters (f/Vt). Certainly, other measures such as patient's mental status should be considered. E.g., a Glasgow Coma Scale
score of less than 8 is an independent indication for intubation.
Mechanical ventilation
In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician, respiratory therapist or other suitable person compressing a bag or set of bellows...
is to be weaned from the ventilator. The weaning process is highly dependent on the patient's pathology, but the final common pathway to ventilator independence always includes at least one trial of spontaneous breathing. Trials of spontaneous breathing have been shown to accurately predict the success of spontaneous breathing.
Indications for trials of spontaneous breathing
- fraction of inspired oxygen (FIO2) less than 50%
- Positive end expiratory pressure (PEEP) less than 8 cm water
- "Minimal vent settings"
- e.g., ratio of arterial partial pressure of oxygen to FIO2 (P/F ratio) in the vicinity of 400
Valid methods
In all of the methods below, the common endpoint measurement is a Rapid Shallow Breathing IndexRapid Shallow Breathing Index
The rapid shallow breathing index is the ratio of respiratory frequency to tidal volume . As an example, a patient who has a respiratory rate of 25 breaths/min and a tidal volume of 250 mL/breath has an RSBI of / = 100 breaths/min/L.Patients who cannot tolerate independent breathing tend to...
(Tobin Index) of less than or equal to 105. The RSBI ("Riz-bee") is simply the ratio of respiratory frequency in respirations per minute to tidal volume in liters (f/Vt). Certainly, other measures such as patient's mental status should be considered. E.g., a Glasgow Coma Scale
Glasgow Coma Scale
Glasgow Coma Scale or GCS is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment...
score of less than 8 is an independent indication for intubation.
- Briefly move the tubing supply from the ventilator to continuous supply oxygen ("wall oxygen")
- Reduce pressure support to 5 cm water
- Reduce continuous positive airway pressure to 5 cm water