title: Diagnosis of abnormal diaphragm motion after cardiothoracic surgery: ultrasound performed by a cardiac intensivist vs. fluoroscopy.
abstract: OBJECTIVE
  Abnormal diaphragmatic motion secondary to phrenic nerve injury is not uncommon after pediatric cardiothoracic surgery. Fluoroscopy is the most frequent method of diagnosis but it carries risks associated with transportation of critically ill children and exposure to ionizing radiation. Ultrasonography, a reliable diagnostic method in adults, eliminates both concerns. Since most cardiac intensivists are trained in echocardiography, we tested the hypothesis that chest ultrasound performed by a cardiac intensivist is faster than fluoroscopy, and is highly accurate in predicting fluoroscopy results, therefore serving as an equally useful diagnostic test.
  
  
  METHODS
  Prospective study in consecutive pediatric patients with suspected abnormal diaphragmatic motion after cardiothoracic surgery. All patients underwent fluoroscopy and ultrasound study of the diaphragm. Ultrasound was performed by a pediatric cardiac intensivist and a trainee. Kappa statistic was calculated to assess concordance between both ultrasound readings. Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated to assess accuracy of each ultrasound test in predicting fluoroscopy results.
  
  
  RESULTS
  Twenty-five patients with median age 3 months (12 days-11 years) and median weight of 3.8 kg (2.5-29 kg) were included. The ultrasound diagnosis of the cardiac intensivist was perfectly accurate (100% sensitivity, specificity, and PPV and NPV) in predicting fluoroscopy results. The ultrasound performed by the trainee achieved 85.7% sensitivity, 94.4% NPV, and 100% specificity relative to fluoroscopy. The interoperator reliability of chest ultrasound was 0.89 (95% confidence interval 0.69-1). Delay between clinical suspicion and the diagnostic tests was 15 minutes (5 minutes-2.5 hours) for ultrasound and 17 hours (60 minutes-82 hours) for fluoroscopy (P < 0.001).
  
  
  CONCLUSIONS
  Chest ultrasound performed by cardiac intensivists allows for an early and accurate diagnosis of abnormal diaphragmatic motion, as evidenced by their ability to predict fluoroscopy findings in pediatric cardiothoracic patients. Training in ultrasound-guided assessment of diaphragmatic motion should be reinforced during pediatric cardiac intensive care fellowship.
authors.affiliation: Division of Cardiac Intensive Care, Department of Pediatrics and Critical Care Medicine, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Penn 15224, USA. sanchezdetoledoj@upmc.edu
authors.forename: Joan
authors.initials: J
authors.lastname: Sanchez de Toledo
authors.forename: Ricardo
authors.initials: R
authors.lastname: Munoz
authors.forename: Douglas
authors.initials: D
authors.lastname: Landsittel
authors.forename: Dana
authors.initials: D
authors.lastname: Shiderly
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yoshida
authors.forename: Rukmini
authors.initials: R
authors.lastname: Komarlu
authors.forename: Peter
authors.initials: P
authors.lastname: Wearden
authors.forename: Victor O
authors.initials: VO
authors.lastname: Morell
authors.forename: Constantinos
authors.initials: C
authors.lastname: Chrysostomou
mesh_terms: D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D002983:Clinical Competence; D003964:Diaphragm / Q000000981:diagnostic imaging* / Q000294:innervation; D005257:Fellowships and Scholarships; D005471:Fluoroscopy; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007396:Internship and Residency; D015588:Observer Variation; D010414:Pennsylvania; D010791:Phrenic Nerve / Q000293:injuries*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012133:Respiratory Paralysis / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012680:Sensitivity and Specificity; D019616:Thoracic Surgical Procedures / Q000009:adverse effects*; D013997:Time Factors; D020196:Trauma, Nervous System / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D014463:Ultrasonography