3. Definitions
⢠Tidal Volume (TV): volume of
each breath.
⢠Rate: breaths per minute.
⢠Minute Ventilation (MV): total
ventilation per minute. MV =
TV x Rate.
⢠Flow: volume of gas per time.
6. Definitions
⢠PIP: maximum pressure measured by
the ventilator during inspiration.
⢠PEEP: pressure present in the airways
at the end of expiration.
⢠CPAP: amount of pressure applied to
the airway during all phases of the
respiratory cycle.
7. Definitions
⢠PS: amount of pressure applied
to the airway during
spontaneous inspiration by the
patient.
⢠I-time: amount of time
delegated to inspiration.
8. Types of Ventilation
⢠Volume Control
⢠Pressure Control
⢠Pressure Support-CPAP
⢠Pressure-Regulated Volume
Control
9. Volume Control
⢠The patient is given a specific volume
of air during inspiration.
⢠The ventilator uses a set flow for a set
period of time to deliver the volume:
⢠TV (cc) = Flow (cc/sec) x i-time (sec)
10. Volume Control
⢠The PIP observed is a product of :
⢠lung compliance, airway
resistance and flow rate.
⢠The ventilator does not react to the
PIP unless the alarm limits are
violated.
11. Volume Control
⢠The PIP tends to be higher
than during pressure control
ventilation to deliver the same
volume of air.
12. Volume Control
⢠With SIMV, the patient can
breath spontaneously between
vent breaths.
⢠This mode is often combined with
PS.
14. Pressure Control
⢠Patient receives a breath at a fixed
airway pressure.
⢠The ventilator adjusts the flow to
maintain the pressure.
⢠Flow decreases throughout the
inspiratory cycle.
15. Pressure Control
⢠The pressure is constant
throughout inspiration.
⢠Volume delivered depends upon the
inspiratory pressure, I-time,
pulmonary compliance and
airway resistance.
16. Pressure Control
⢠The delivered volume can vary from
breath-to-breath depending upon the
above factors. MV not assured.
⢠Good mode to use if patient has large
air leak, because the ventilator will
increase the flow to compensate it.
19. CPAP-Pressure Support
â˘No mandatory breaths
⢠Patient sets the rate, I-time, and
respiratory effort.
⢠CPAP performs the same function as
PEEP, except that it is constant
throughout the inspiratory and
expiratory cycle.
20. CPAP-Pressure Support
⢠Pressure Support (PS) helps to
overcome airway resistance and
inadequate pulmonary effort and is
added on top of the CPAP
during inspiration.
21. CPAP-Pressure Support
⢠The ventilator increases the
flowduring inspiration to reach
the target pressure and make it easier
for the patient to take a breath.
23. Pressure-Regulated Volume
Control
⢠In this mode, a target minute
ventilation is set.
⢠The ventilator will adjust the flow to
deliver the volume without exceeding a
target inspiratory pressure.
â˘Decelerating flow pattern.
24. Pressure-Regulated Volume
Control
⢠No change in minute
ventilation if pulmonary
conditions change.
⢠Can ventilate at a lower PIP than in
regular volume control.
30. pCO2 Too High
⢠Patientâs minute ventilation is too
low.
⢠Increase rate or TV or both.
⢠If using PC ventilation, increase PIP.
⢠If PIP too high, increase the rate
instead.
31. pCO2 Too High
⢠If air-trapping is occurring, decrease
the rate and the I-time and increase
the TV to allow complete exhalation.
⢠Sometimes, you have to live with the
high pCO2, so use THAM or
bicarbonate to increase the pH to
>7.20.
32. pCO2 Too Low
⢠Minute ventilation is too high.
⢠Lower either the rate or TV.
⢠Donât need to lower the TV if the
PIP is <20.
⢠PIP <24 is fine unless delivered TV
is still >15ml/kg.
33. pCO2 Too Low
⢠TV needs to be 8ml/kg or higher to
prevent progressive atelectasis
⢠If patient is spontaneously breathing,
consider lowering the pressure
support if spontaneous TV >7ml/kg.
34. pO2 Too High
⢠Decrease the FiO2.
⢠When FiO2 is less than 40%,
decrease the PEEP to 3-5 cm
H2O.
⢠Wean the PEEP no faster than
about 1 every 8-12 hours.
35. pO2 Too High
⢠While patient is on ventilator,
donât wean FiO2 to
<25%
to give the patient a margin of
safety in case the ventilator quits.
36. pO2 Too Low
⢠Increase either the FiO2 or the mean
airway pressure (MAP).
⢠Try to avoid FiO2 >70%.
⢠Increasing the PEEP is the most efficient
way of increasing the MAP in the PICU.
⢠Can also increase the I-time to
increase the MAP (PC).
37. pO2 Too Low
⢠Can increase the PIP in Pressure
Control to increase the MAP,
but this generally doesnât add
much at rates <30 bpm.
38. pO2 Too Low
⢠May need to increase the PEEP to
over 10, but try to stay <15
if possible.
39. PIP Too High
⢠Decrease the PIP (PC) or the TV
(VC).
⢠Increase the I-time (VC).
⢠Change to another mode of
ventilation.
Generally, pressure control achieves
the same TV at a lower PIP than
volume control.
40. PIP Too High
⢠If the high PIP is due to high
airway resistance, generally
the lung is protected from
barotrauma unless air-
trapping occurs.
41. Weaning Priorities
⢠Wean PIP to <35cm H2O
⢠Wean FiO2 to <60%
⢠Wean I-time to <50%
⢠Wean PEEP to <8cm H2O
⢠Wean FiO2 to <40%
42. Weaning Priorities
⢠Wean PEEP, PIP, I-time, and rate
towards extubation settings.
â˘Can consider changing to
volume control ventilation
when PIP <35cm H2O.
55. Neurologic
⢠Protect his airway, e.g, have
cough, gag, and swallow
reflexes.
⢠low Level of sedation
⢠No apnea on the ventilator.
56. Neurologic
⢠Must be strong enough to generate a
spontaneous TV of 5-7ml/kg on 5-10
cm H2O PS
⢠or have a negative inspiratory force
(NIF) of 25cm H2O or higher.
⢠Being able to follow commands
is preferred.
57. Cardiovascular
⢠Patient must be able to increase
cardiac output to meet demands
of work of breathing.
⢠Adequate cardiac output without
being on significant inotropic support.
⢠Hemodynamically stable.
58. Pulmonary
⢠Patient should have a patent airway.
⢠If no air leak, consider decadron and
racemic epinephrine.
⢠Pulmonary compliance and
resistance should be near normal.
59. Pulmonary
⢠Patient should have normal blood gas and
work-of-breathing on the following settings:
âFiO2 <40%
âPEEP 3-5cm H2O
âPS 5-8cm H2O
âSpontaneous TV of 5-7ml/kg
âAdequate RR
