Effect of residual leaning force on intrathoracic pressure during mechanical ventilation in children.
OBJECTIVE
Determine the effect of residual leaning force on intrathoracic pressure (ITP) in healthy children receiving mechanical ventilation. We hypothesized that application of significant residual leaning force (2.5kg or 20% of subject body weight) would be associated with a clinically important change in ITP.


METHODS
IRB-approved pilot study of healthy, anesthetized, paralyzed mechanically ventilated children (6 months to 7 years). Peak endotracheal pressure (ETP), a surrogate of ITP, was continuously measured before and during serial incremental increases in sternal force from 10% to 25% of the subject's body weight. A delta ETP of >or=2.0cmH(2)O was considered clinically significant.


RESULTS
13 healthy, anesthetized, paralyzed mechanically ventilated children (age: 26+/-24m, range: 6.5-87m; weight: 13+/-5kg, range: 7.4-24.8kg) were enrolled. Peak ETP increased from baseline for all force applications (10% body weight: mean difference of 0.8cmH(2)O, p<0.01; 15% body weight: mean difference of 1.1cmH(2)O, p<0.01; 20% body weight: mean difference of 1.5cmH(2)O, p<0.01; 25% body weight: mean difference of 1.89cmH(2)O, p<0.01). Residual leaning force of >or=2.5kg was associated with a 2.0cmH(2)O change in peak ETP (odds ratio 7.5; CI(95) 1.5-37.7; p=0.014) while sternal force >or=20% body weight was not (odds ratio 2.4; CI(95) 0.6-9.2; p=0.2).


CONCLUSIONS
In healthy anesthetized children, changes in ETP were detectable at residual leaning forces as low as 10% of subject body weight. Residual leaning force of 2.5kg was associated with increases in ETP >or=2.0cmH(2)O.
Sutton
Robert Michael
RM
The Children's Hospital of Philadelphia, Department of Anesthesia, Critical Care and Pediatrics, Philadelphia, PA 19104, USA. suttonr@email.chop.edur
Niles
Dana
D
Nysaether
Jon
J
Stavland
Mette
M
Thomas
Melissa
M
Ferry
Susan
S
Bishnoi
Ram
R
Litman
Ronald
R
Allen
Julian
J
Srinivasan
Vijay
V
Berg
Robert A
RA
Nadkarni
Vinay M
VM
D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D007223:Infant; D007442:Intubation, Intratracheal / Q000379:methods*; D008297:Male; D016017:Odds Ratio; D009873:Operating Rooms; D010865:Pilot Projects; D011187:Posture; D011312:Pressure; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000379:methods*; D015656:Respiratory Mechanics; D018570:Risk Assessment; D035423:Thoracic Cavity; D016896:Treatment Outcome; D013520:Urologic Surgical Procedures
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