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Tidal Volume

(See Compliance/Resp Failure) 
- normal Tidal Volume w/ spontaneous breathing is 5 ml/kg; 
- w/ Ventilator, Initially set at 10-15 cc/kg body wt, in Newborns as well as Adults; 
- adjust as needed w/ ABG; 
- Tidal vol may need to be increased in individuals w/ Resp acidosis despite adequate frequency of ventialation; 
- w/ high pCO2: must increase Minute Vol
- if tidal volume is already at the upper limits of suggested range, or if peak inspiratory pressures are high ( > 60), or if there is prominent chest expansion w/ each breath, one would be inclined to increase rate rather than volume; 
- if rate is already at upper limits of range, or if peak inspiratory pressures are low, and if chest expansion w/ each breath is not marked, TV may be safely increased; 
- w/ Low pCO2: must decrease Minute Vol 
- note: mild respiratory alkalosis is desirable, and usually minute ventilation is not decrease unless pCO2 < 30 mm Hg) - decr min. volume may occur by decr rate or tidal volume. 
- however, a illogical method is by increasing the length of ventilator tubing. (some illogically believe that by decreasing Minute Vol by other methods might decr oxygenation.)