title: Detection of pulsus paradoxus associated with large pericardial effusions in pediatric patients by analysis of the pulse-oximetry waveform.
abstract: OBJECTIVE
  To determine whether analysis of the pulse-oximetry waveform can be useful in detecting the pulsus paradoxus associated with large pericardial effusions in pediatric patients.
  
  
  METHODS
  A retrospective review of charts of 8 pediatric patients (age range: 5-19 years) who had echocardiographic evidence of large pericardial effusion, subsequently underwent pericardiocentesis, and had pulse-oximetry waveform tracings obtained before and after pericardiocentesis within an 18-month period was conducted in 2 tertiary-care pediatric intensive care units. We analyzed the pulse-oximetry waveform tracings for the presence of a pulsus paradoxus. Other abstracted data included clinical evidence of tamponade, echocardiographic findings, and the volume of pericardial fluid aspirated.
  
  
  RESULTS
  Before pericardiocentesis, a decrease in the highest value of the upper plethysmographic peak of the pulse-oximetry waveform was observed during inspiration in each patient. Echocardiographic evidence of large pericardial effusion with compromised cardiac filling was also present in each patient. Only 6 of these patients had clinical evidence of cardiac tamponade at that time, 4 with a documented pulsus paradoxus using standard methods of blood pressure analysis. After pericardiocentesis, the inspiratory fall in the highest value of the upper plethysmographic peak of the pulse-oximetry waveform lessened in every patient. Echocardiography documented a decrease in the size of the effusion and resolution of the compromised cardiac filling in every patient.
  
  
  CONCLUSIONS
  Analysis of pulse-oximetry waveforms may be a widely available, easily interpretable, and reliable method of detecting the pulsus paradoxus associated with large pericardial effusions in pediatric patients.
authors.affiliation: Division of Critical Care Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA. robert.tamburro@stjude.org
authors.forename: Robert F
authors.initials: RF
authors.lastname: Tamburro
authors.forename: John C
authors.initials: JC
authors.lastname: Ring
authors.forename: Kimberly
authors.initials: K
authors.lastname: Womback
mesh_terms: D000293:Adolescent; D000328:Adult; D002305:Cardiac Tamponade / Q000175:diagnosis / Q000209:etiology; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D006801:Humans; D010092:Oximetry; D010490:Pericardial Effusion / Q000150:complications* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011674:Pulse; D012189:Retrospective Studies