weaning from mechanical ventilation

1. Weaning From Mechanical
Ventilation
As soon as mechanical ventilation starts , plans
begin for weaning the patient from mechanical
support. The process to achieve the goal includes
correcting cause of respiratory failure, preventing
complications and restoring physiological and
psychological functional status.

2. Categories of Ventilation
Short term ventilation
• "Short-term ventilation"
typically refers to providing
respiratory support for a
brief duration to individuals
who are temporarily unable
to maintain adequate
breathing on their own.
Long term ventilation
• "Long-term ventilation" refers
to the extended use of
respiratory support for
individuals who have chronic
respiratory conditions or
conditions that significantly
impair their ability to breathe
independently over an
extended period.

3. Guidelines for Weaning from Short
term Ventilation
Readiness criteria:
 Hemodynamically stable, adequately resuscitated
and not requiring vasoactive support
 Sao2 greater than 90% on FiO2 40% or less
 Hematocrit more than 25%
 Core temperature more than 36C or less than 39C
 No residual neuromuscular blockade
 ABGs values normalized

4.  Weaning Intervention:
 Ventilator rate, than convert to pressure support
ventilation only.
 Wean PSV as tolerated to 10cm H2O or less.
 If Patient meets tolerance criteria for at least 2 hours on
this level of support and meets extubation criteria may
extubate.
 If patient fails tolerance criteria, increase PSV.
 Repeat wean attempt on PSV 10cm after rest period. If
patient fails second wean trial, return to rest settings and
use long tern ventilation weaning approach.

5. Guidelines for Weaning from Long
term Ventilation
• Same as for short term ventilation, with emphasis on
hemodynamic stability, adequate analgesia/sedation
and normalizing volume status.

6. Weaning Intervention
 Transfer to PSV mode, adjust support level to maintain
patient’s respiratory rate at less than 35 breaths/min.
 Observe for 30 minutes for signs of early failure.
 If tolerated, continue trial for 2 hours then return patient
to rest settings by adding ventilator breaths or increasing
PSV to achieve a total respiratory rate of less than 20
breaths/min.
 After at least 2 hours of rest, repeat trial for 2 to 4 hours
at same PSV level as previous trial.
 Record the results of each weaning episode.

7.  The goal is to increase the length of trials and reduce
PSV level needed on an incremental level basis. With
each successive trial, the PSV may be decreased by 2
to 4cm H2O, the time interval may be increased to 1
to 2 hours or both while keeping the patient within
tolerable parameters.
 Ensure nocturnal ventilation at rest settings for at
least 6 hours each night until the patient’s weaning
trials demonstrate readiness to discontinue
ventilatory support.