title: Parsonnet score is a good predictor of the duration of intensive care unit stay following cardiac surgery.
abstract: OBJECTIVE
  To investigate the value of the Parsonnet score (PS) in identifying preoperatively patients that are likely to spend < 24 hours on the intensive care unit (ICU) following cardiac surgery.
  
  
  METHODS
  Prospectively collected data on 5591 patients were analysed. PS, mortality, the length of stay on the ICU (ICU-LOS), number of patients with clinical evidence of stroke, need for haemofiltration, resternotomy for bleeding, tracheostomy, and use of intra-aortic balloon pump were documented as outcomes. A receiver operating characteristic (ROC) curve constructed using PS as a predictor of ICU stay < 24 hours identified a PS of 10 as the best cut off point that would predict ICU-LOS < 24 hours. The patients were therefore stratified by PS into two groups, those with a PS of 0 to 9 (PS 0-9) and those with a PS of 10 and above (PS 10+).
  
  
  RESULTS
  The ROC curve constructed using PS as a predictor of ICU stay < 24 hours had an area under the curve of 0.70 (0.01). The maximum efficiency of the test was at a sensitivity of 0.68. This corresponded to PS 10. The positive predictive value of the test at this score was 90.5%. Patients with PS 0-9 had a mean ICU stay of 1.49 days, while patients with PS 10+ had a mean ICU stay of 2.89 days (p = 0.01). The risk of stroke, use of intra-aortic balloon pump, requirement for haemofiltration, need for tracheostomy, and risk of resternotomy for bleeding were each significantly less in patients with PS 0-9 versus those with a score of PS 10+ (p < 0.01 in all cases). The risk of a single complication was 4.7% (PS 0-9) v 15.2% (PS 10+) (p < 0.01).
  
  
  CONCLUSIONS
  PS is an impartial and objective method of predicting postoperative complications and ICU stay < 24 hours. This is of value in selecting a cohort of patients likely to maintain a smooth flow of patients through the cardiothoracic unit when resources are limited to a few free ICU beds.
authors.affiliation: Department of Cardiothoracic Surgery, St George's Hospital, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: D R
authors.initials: DR
authors.lastname: Lawrence
authors.forename: O
authors.initials: O
authors.lastname: Valencia
authors.forename: E E
authors.initials: EE
authors.lastname: Smith
authors.forename: A
authors.initials: A
authors.lastname: Murday
authors.forename: T
authors.initials: T
authors.lastname: Treasure
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration*; D007902:Length of Stay; D008131:London; D008297:Male; D011182:Postoperative Care; D011183:Postoperative Complications; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors