title: Transesophageal echocardiography probe insertion failure in infants undergoing cardiac surgery.
abstract: BACKGROUND
  The use of intraoperative transesophageal echocardiography (iTEE) in neonates ≤4 kg has not been systematically described. We sought to describe the use of and determine risk factors for iTEE probe insertion failure in small infants. We also sought to develop an algorithm for predicting the likelihood of iTEE probe insertion failure.
  
  
  METHODS
  A retrospective chart review of all neonates ≤4 kg who underwent cardiac surgery at our institution from 12/2001 to 12/2006 was performed. Patients who underwent operations that did not typically require TEE were excluded. Risk factors for TEE probe insertion failure were assessed.
  
  
  RESULTS
  Of 310 neonates who met the inclusion criteria, 219 (70%) underwent successful iTEE. Lower weight (P <.001), abnormal craniofacial anatomy (P =.03), prematurity (P =.015), and 22q11 deletion (P =.04) were independently associated with iTEE probe insertion failure. Stratified by weight, there was an 80% predicted probability of iTEE probe insertion failure for infants weighing: 2 kg with any two of the above risk factors and 3 kg with any three of the above risk factors. There was less than an 80% predicted likelihood of iTEE probe insertion failure for infants weighing 4 kg regardless of other risk factor status.
  
  
  CONCLUSIONS
  iTEE can be successfully performed in the majority of neonates ≤4 kg undergoing cardiac surgery. However, there are identifiable risk factors for iTEE probe insertion failure. A weight-based algorithm may help determine neonates at risk for iTEE probe insertion failure. Smaller TEE probes may benefit this patient population.
authors.affiliation: Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA. shari.wellen@gmail.com
authors.forename: Shari L
authors.initials: SL
authors.lastname: Wellen
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Glatz
authors.forename: J William
authors.initials: JW
authors.lastname: Gaynor
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Montenegro
authors.forename: Meryl S
authors.initials: MS
authors.lastname: Cohen
mesh_terms: D000465:Algorithms; D001724:Birth Weight; D006348:Cardiac Surgical Procedures; D017548:Echocardiography, Transesophageal / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D018084:Ultrasonography, Interventional / Q000295:instrumentation*