CCM Notes
ICU Essentials · Mechanical Ventilation
Ventilator Initial Settings
Modes · Initial Parameters by Condition · Targets · Alarms
🔧 Ventilation Modes
A/C — VC
Assist-Control, Volume-Cycled
Delivers set TV every breath (patient or time-triggered).
Guarantees minute ventilation.
Most common mode in ICU.
First-line ICU
SIMV
Synchronized IMV
Delivers set rate of mandatory breaths + allows spontaneous breathing in between.
Slower weaning, more WOB.
Weaning mode
PSV / SBT
Pressure Support Ventilation
All breaths patient-triggered. Set pressure support only.
Used for weaning, SBT.
Requires adequate drive.
Weaning / SBT
📋 Initial Settings by Condition
4–6 mL/kg IBW
Low TV = lung protective
6–8 mL/kg IBW
Allow full exhalation
6–8 mL/kg IBW
Standard volumes
16–35 /min
Compensate for low TV
10–14 /min
Low rate → exhalation time
12–16 /min
Normal physiology
Start 100%
Wean to SpO₂ 88–95%
Start 40–60%
Target SpO₂ 88–92%
Start 40–60%
Wean quickly to <60%
8–16 cmH₂O
Use ARDSnet table
3–5 cmH₂O
Avoid air trapping
5–8 cmH₂O
Physiologic PEEP
1:3 to 1:4
Prevent auto-PEEP
📐 IBW Formula (for TV calculation)
Males (kg)
50 + 2.3 × [height(in) − 60]
Females (kg)
45.5 + 2.3 × [height(in) − 60]
1 inch = 2.54 cm | Height in cm ÷ 2.54
Never use actual body weight for TV in ARDS
🎯 Key Ventilator Targets
Pplat (plateau)
≤30 cmH₂O
Driving pressure
≤15 cmH₂O
PaCO₂
35–45 (permissive ↑ ok in ARDS)
Plateau Pressure
≤30
cmH₂O — reduce TV if exceeded
PIP Alarm
+10
cmH₂O above PIP — high alarm
Auto-PEEP
0–3
cmH₂O target — esp. in obstructive disease
Minute Vol
8–15
L/min typical; alarm ±3L from baseline
🫁 ARDS: Proning
Prone if P/F ratio <150 on FiO₂ ≥60%, PEEP ≥5
Prone 16–18 hours/session
Continue lung-protective settings while prone
NMBA: cisatracurium 48h if P/F <150
Prone reduces mortality ~50% in severe ARDS (PROSEVA)