Initial mechanical ventilation settings

Revision as of 20:53, 22 July 2011 by Rossdonaldson1 (talk | contribs) (See Also)

Initial

  1. FiO2 100% and ween down
  2. Rate 8-12/min (consider 5-6 for asthma w/ permissive hypercapnea)
  3. Mode
    1. A/C = defalt (most)
    2. SIMV = with obstructive airway disease and an intact respiratory effort (e.g. some COPD, asthma)
    3. PC = with intact respiratory effort and non-severe respiratory failure (prefered in chronic vent)
  4. Peep 0-5 mmH20
  5. TV 5-8 cc/kg (eg. 500-600cc) (adjust to plateau pressure <35 cmH20)
  6. I/E 1:3
  7. PS (pressure support) 5-8cm to overcome ET

Table

DZ TV^ RR I:E PEEP

Nl lung 8 10-12 1:2 4

Obstruct 6 5-8 1:4 4

ARDS 6 12-20 1:2 2-15

Hypovol 8 10-12 1:2 0-4

^cc/kg

^^FiO2 always = 1.0


Changes

O2

  1. PaO2 (ween to SaO2 >90% & PaO2 >60)
  2. FiO2 (ween to <0.5 if poss)
  3. PEEP (see ARDS schedule; if >10, should have art line)
    1. (rule of 7s: decrease 1 FiO2 = 7 pO2)

CO2

  1. PCO2
    1. TV
    2. Rate
  2. (VE-1 x pCO2-1 = VE-2 x pCO2-2)
    1. VE = minute ventilation (RR x TV)

pH

to increase pH 0.01 --> decrease pCO2 by 1

MISC (normally already set)

  1. Inspiratory flow rate = 60L/min (100L/min with asthma)
  2. Sensitivity = 1-2 cmH2O

MODES

A/C = Assist Control

  1. (helps instigated breaths, extra breaths all of set TV)
  2. delivers preset breaths (full assisted tidal volume) in coordination with the respiratory effort
  3. spontaneous breathing (above rate) is not allowed
  4. beneficial for patients requiring a high minute-ventilation (reduces oxygen consumption and CO2 production of the respiratory muscles)
  5. may worsen obstructive airway disease by air trapping or breath stacking

SIMV = Synchronous Intermittent Mandatory Ventilation

  1. (senses not to give with breathing if present, extra breaths of pt's TV)
  2. preset breaths in coordination with the respiratory effort
  3. spontaneous breathing allowed between breaths
  4. synchronization attempts to limit the barotrauma by not delivering a breath when already maximally inhaled (vs. IMV)

PS = Pressure Support

  1. (controls via pressure, good if pressures getting too high)
  2. limits barotrauma and decreases the work of breathing in the spontaneously breathing patient
  3. level of pressure set (not TV) to assist spontaneous efforts
  4. most ventilators allow back-up respiratory rate (in case of apnea)
  5. mode of choice in patients whose respiratory failure is not severe and who have an adequate respiratory drive (improved patient comfort, reduced cardiovascular effects, reduced risk of barotrauma, and improved distribution of gas)

^For the paralyzed patient, there is no difference in minute-ventilation or airway pressures between A/C and SIMV

See Also

Source

2/8/06 DONALDSON (adapted from emedicine, Lampe)