title: Effect of residual leaning force on intrathoracic pressure during mechanical ventilation in children.
abstract: 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.
authors.affiliation: The Children's Hospital of Philadelphia, Department of Anesthesia, Critical Care and Pediatrics, Philadelphia, PA 19104, USA. suttonr@email.chop.edur
authors.forename: Robert Michael
authors.initials: RM
authors.lastname: Sutton
authors.forename: Dana
authors.initials: D
authors.lastname: Niles
authors.forename: Jon
authors.initials: J
authors.lastname: Nysaether
authors.forename: Mette
authors.initials: M
authors.lastname: Stavland
authors.forename: Melissa
authors.initials: M
authors.lastname: Thomas
authors.forename: Susan
authors.initials: S
authors.lastname: Ferry
authors.forename: Ram
authors.initials: R
authors.lastname: Bishnoi
authors.forename: Ronald
authors.initials: R
authors.lastname: Litman
authors.forename: Julian
authors.initials: J
authors.lastname: Allen
authors.forename: Vijay
authors.initials: V
authors.lastname: Srinivasan
authors.forename: Robert A
authors.initials: RA
authors.lastname: Berg
authors.forename: Vinay M
authors.initials: VM
authors.lastname: Nadkarni
mesh_terms: 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
references.citation: Respir Care. 2005 May;50(5):628-35
references.pmid: 15871757
references.citation: Pediatrics. 2009 Aug;124(2):494-9
references.pmid: 19581266
references.citation: Circulation. 2004 Apr 27;109(16):1960-5
references.pmid: 15066941
references.citation: Resuscitation. 2009 May;80(5):553-7
references.pmid: 19297068
references.citation: Resuscitation. 2005 Mar;64(3):353-62
references.pmid: 15733766
references.citation: Circulation. 2005 Feb 1;111(4):428-34
references.pmid: 15687130
references.citation: Stapp Car Crash J. 2008 Nov;52:83-105
references.pmid: 19085159
references.citation: Resuscitation. 2005 Mar;64(3):363-72
references.pmid: 15733767
references.citation: Resuscitation. 2007 Mar;72(3):364-70
references.pmid: 17141936
references.citation: J Appl Physiol (1985). 1995 Jan;78(1):179-84
references.pmid: 7713809
references.citation: Arch Intern Med. 2008 May 26;168(10):1063-9
references.pmid: 18504334
references.citation: Resuscitation. 2006 Nov;71(2):137-45
references.pmid: 16982127
references.citation: JAMA. 2005 Jan 19;293(3):305-10
references.pmid: 15657323
references.citation: Crit Care Med. 2010 Apr;38(4):1141-6
references.pmid: 20081529
references.citation: Resuscitation. 2007 Apr;73(1):54-61
references.pmid: 17258853
references.citation: JAMA. 2005 Jan 19;293(3):299-304
references.pmid: 15657322
references.citation: Resuscitation. 2006 Dec;71(3):283-92
references.pmid: 17070980
references.citation: Crit Care Med. 2004 Sep;32(9 Suppl):S345-51
references.pmid: 15508657
references.citation: Fed Proc. 1980 Aug;39(10):2771-5
references.pmid: 7409203