Work of breathing and volume targeted ventilation in respiratory distress.
OBJECTIVE
To determine the level of volume targeting (VT) associated with the lowest work of breathing (WOB) for prematurely born infants being ventilated with acute respiratory distress.


METHODS
Prospective study.


METHODS
Tertiary neonatal intensive care unit.


METHODS
18 infants, median gestational age 29 (range 25-34) weeks, being ventilated for acute respiratory distress.


METHODS
Infants were studied first without VT (baseline). Volume targeted levels of 4 ml/kg, 5 ml/kg and 6 ml/kg were then delivered in random order. After each VT level, the infants were returned to baseline. Each step was maintained for 20 minutes.


METHODS
The transdiaphragmatic pressure time product (PTPdi) as an estimate of the WOB.


RESULTS
The mean PTPdi was higher at a VT level of 4 ml/kg (median 154 cm H(2)O·s/min) compared to baseline (median 112 cm H(2)O·s/min) (p<0.001) and a VT level of 6 ml/kg (median 89 cm H(2)O·s/min) (p<0.001).


CONCLUSIONS
A low level of VT increased the WOB in infants with acute respiratory distress syndrome. The authors' results suggest that, during acute respiratory distress, a VT level of at least 5 ml/kg rather than a lower level might avoid an increased WOB. The most appropriate level of VT needs to be determined in a randomised controlled trial with long-term outcomes.
Patel
Deena-Shefali
DS
Division of Asthma, Allergy and Lung Biology, MRC Asthma Centre for Allergic Mechanisms of Asthma, King's College London, London, UK.
Rafferty
Gerrard F
GF
Lee
Silke
S
Hannam
Simon
S
Greenough
Anne
A
D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D015931:Intensive Care, Neonatal / Q000379:methods; D007385:Intermittent Positive-Pressure Ventilation / Q000379:methods*; D008297:Male; D011446:Prospective Studies; D012127:Respiratory Distress Syndrome, Newborn / Q000503:physiopathology / Q000628:therapy*; D014939:Work of Breathing / Q000502:physiology*