PCV

1
PCV
2
PCV

• Goals
• Improve distribution of ventilation to perfusion
  by increased recruitment of atelectatic alveoli
• Reduce potential for barotrauma
• Improve oxygenation by increasing FRC
• Low static compliance will result in increased
  expiratory flowrates because of
• Increased elastic forces of the diseased lung
• Increased surface tension in the alveoli

3
PCV

• Bilevel
• PCV with an active exhalation valve which allows
  the patient to breath spontaneously at two levels
  of pressure HPEEP, LPEEP
• In the SIMV mode, P/S can be used
• Patients desire to breathe because of varying
  concentrations of PaCO2 stimulate the
  chemoreceptor system in the respiratory center of
  the brain

4
PCV

• Bilevel
• Spontaneous breathing is active breathing which
  helps to improve V/Q matching in the dependent
  West zones II and III
• Patients are more comfortable breathing on this
  mode and require little to no sedation as
  required in Pressure Control Inverse Ratio
  Ventilation (PCIRV)

5
PCV

• Bilevel ventilator settings
• RR 10 14 bpm or similar to VCV
• TI 1.5 seconds and increase in increments of
  0.25 seconds until P/F ratio is gt 200
• HPEEP initially set at 20 cmH2O up to 40
  cmH2O. Set ?P to reflect an exhaled TV of
  6 7 cc/kg of IBW

6
PCV

• Bilevel ventilator settings
• LPEEP 5 cmH2O for typical patient or 10 15
  cmH2O in ARDS patients. Can use optimal
  peep trials or lower inflection point on
  the pressure vs. volume curve. The goal of
  using LPEEP is the same as it was in VCV

7
PCV

• Bilevel ventilator settings
• P/S is set above the level of LPEEP so that
  LPEEP P/S HPEEP
• Vsens default is 5 lpm, but 6 8 lpm may be
  necessary to avoid autocycling. Total RR should
  equal patients actual rate
• Esens 25
• Rise Time 50

8
PCV

• Bilevel managing
• HPEEP LPEEP inflating pressure to generate a
  TV aka ?P
• To alter minute volume and control PaCO2, either
  altering ?P to change TV or altering the rate. If
  the patient is breathing at LPEEP, alter P/S
  level
• If autoPeep is seen and not desired, decrease
  rate and increase ?P, i.e., lengthen TE

9
PCV

• Bilevel Weaning
• Similar to VCV
• Decrease the rate until off so that the patient
  is only on LPEEP and P/S