Lecture 9a - Weaning from Ventilatory support

Question 1

what is the timeframe for weaning

Answer 1

<12 hr quick

over days/weeks - planned reduction in support

Question 2

When do we start weaning

Answer 2

reversal of the causes of ventilation failure
able to initiate spontaneous breath
low peep (<5) and low fio2 (<4.5)
cardiovascular stability

Question 3

What are 2 methods of weaning

Answer 3

• step down assistance: decrease SIMV rate –> PSV –> CPAP

- T-piece: trachea attachment - icnrease time off support –> decreased night time support

Question 4

What are 3 factors that influence weaning

Answer 4

energy supply
energy demand
neuromuscular function

Question 5

Why do patients fail to wean

Answer 5

• mismatch between energy supply and demands
• mismatch between vent needs and neuromuscular respiratory capacity
• psychological factors
• 20% of patients fail to wean - more difficult with age, prolonged vent, COPD

Question 6

what is the role of physio in weaning?

Answer 6

minimize peripheral deconditioning - mobilization
secretion clearance
issues of atelectasis, decrease FRC, decrease VT
optimize positioning
optimize rr mm mechanics
reassurance
institute NIV