title: Outcomes of acute chest syndrome in adult patients with sickle cell disease: predictors of mortality.
abstract: Adults with sickle cell disease(SCD) are a growing population. Recent national estimates of outcomes in acute chest syndrome(ACS) among adults with SCD are lacking. We describe the incidence, outcomes and predictors of mortality in ACS in adults. We hypothesize that any need for mechanical ventilation is an independent predictor of mortality.
  
  
  METHODS
  We performed a retrospective analysis of the Nationwide Inpatient Sample(2004-2010),the largest all payer inpatient database in United States, to estimate the incidence and outcomes of ACS needing mechanical ventilation(MV) and exchange transfusion(ET) in patients >21 years. The effects of MV and ET on outcomes including length of stay(LOS) and in-hospital mortality(IHM) were examined using multivariable linear and logistic regression models respectively. The effects of age, sex, race, type of sickle cell crisis, race, co-morbid burden, insurance status, type of admission, and hospital characteristics were adjusted in the regression models.
  
  
  RESULTS
  Of the 24,699 hospitalizations, 4.6% needed MV(2.7% for <96 hours, 1.9% for ≥96 hours), 6% had ET, with a mean length of stay(LOS) of 7.8 days and an in-hospital mortality rate(IHM) of 1.6%. There was a gradual yearly increase in ACS hospitalizations that needed MV(2.6% in 2004 to 5.8% in 2010). Hb-SS disease was the phenotype in 84.3% of all hospitalizations. After adjusting for a multitude of patient and hospital related factors, patients who had MV for <96 hours(OR = 67.53,p<0.01) or those who had MV for ≥96 hours(OR = 8.73,p<0.01) were associated with a significantly higher odds for IHM when compared to their counterparts. Patients who had MV for ≥96 hours and those who had ET had a significantly longer LOS in-hospitals(p<0.001).
  
  
  CONCLUSIONS
  In this large cohort of hospitalized adults with SCD patients with ACS, the need for mechanical ventilation predicted higher mortality rates and increased hospital resource utilization. Identification of risk factors may enable optimization of outcomes.
authors.affiliation: Assistant Professor of Pediatrics, Pediatric Critical Care, Rainbow Babies and Children's Hospital, Cleveland, Ohio, United States of America.
authors.forename: Veerajalandhar
authors.initials: V
authors.lastname: Allareddy
authors.affiliation: Fellow, Pediatric Critical Care Medicine, Rainbow Babies and Children's Hospital, Cleveland, Ohio, United States of America.
authors.forename: Aparna
authors.initials: A
authors.lastname: Roy
authors.affiliation: Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts, United States of America.
authors.forename: Min Kyeong
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Instructor, Dental Medicine, Harvard University, Boston, Massachusetts, United States of America.
authors.forename: Romesh P
authors.initials: RP
authors.lastname: Nalliah
authors.affiliation: Advanced Graduate Student, Texas A & M University, College station, Texas, United States of America.
authors.forename: Sankeerth
authors.initials: S
authors.lastname: Rampa
authors.affiliation: Associate Professor, Department of Orthodontics, University of Iowa; Iowa, United States of America.
authors.forename: Veerasathpurush
authors.initials: V
authors.lastname: Allareddy
authors.affiliation: Professor of Pediatrics, Pediatric Critical Care, Rainbow Babies and Children's Hospital, Cleveland, Ohio, United States of America.
authors.forename: Alexandre T
authors.initials: AT
authors.lastname: Rotta
mesh_terms: D056586:Acute Chest Syndrome / Q000150:complications / Q000453:epidemiology / Q000401:mortality*; D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D015999:Multivariate Analysis; D012044:Regression Analysis; D012121:Respiration, Artificial; D012189:Retrospective Studies
references.citation: N Engl J Med. 2000 Jun 22;342(25):1855-65
references.pmid: 10861320
references.citation: JAMA. 2003 Apr 2;289(13):1645-51
references.pmid: 12672732
references.citation: Blood. 2004 Jun 1;103(11):4023-7
references.pmid: 14764527
references.citation: Am J Hematol. 2010 Oct;85(10):795-7
references.pmid: 20645429
references.citation: N Engl J Med. 2008 Nov 20;359(21):2254-65
references.pmid: 19020327
references.citation: Am J Hematol. 2005 May;79(1):17-25
references.pmid: 15849770
references.citation: Pediatr Blood Cancer. 2011 Feb;56(2):262-6
references.pmid: 21157894
references.citation: Am J Hematol. 2011 Apr;86(4):377-80
references.pmid: 21442644
references.citation: N Engl J Med. 2010 Mar 25;362(12):1110-8
references.pmid: 20335587
references.citation: Chest. 2000 May;117(5):1386-92
references.pmid: 10807826
references.citation: Br Med J (Clin Res Ed). 1982 Aug 28-Sep 4;285(6342):633-5
references.pmid: 6819042
references.citation: Ann Intern Med. 2002 Sep 17;137(6):511-20
references.pmid: 12230353
references.citation: Clin Chest Med. 2006 Sep;27(3):487-502, vii
references.pmid: 16880058
references.citation: Semin Hematol. 1991 Jul;28(3):220-6
references.pmid: 1887248
references.citation: JAMA. 2007 Jan 3;297(1):71-6
references.pmid: 17200477
references.citation: Pediatrics. 2013 Nov;132(5):854-61
references.pmid: 24167173
references.citation: N Engl J Med. 1994 Jun 9;330(23):1639-44
references.pmid: 7993409
references.citation: Pediatr Blood Cancer. 2005 Feb;44(2):182-6
references.pmid: 15390359
references.citation: Blood. 2010 Apr 29;115(17):3447-52
references.pmid: 20194891
references.citation: Lancet. 2011 May 14;377(9778):1663-72
references.pmid: 21571150
references.citation: J Pediatr. 1995 Dec;127(6):901-4
references.pmid: 8523186
references.citation: Blood. 1994 Jul 15;84(2):643-9
references.pmid: 7517723
references.citation: Am J Dis Child. 1988 Feb;142(2):178-82
references.pmid: 3341320
references.citation: Sultan Qaboos Univ Med J. 2012 May;12(2):177-83
references.pmid: 22548136
references.citation: Ann Surg. 2007 Nov;246(5):875-85
references.pmid: 17968182
references.citation: Medicine (Baltimore). 1988 Jan;67(1):66-76
references.pmid: 3336282
references.citation: N Engl J Med. 1995 Jul 27;333(4):206-13
references.pmid: 7791837
references.citation: Blood. 1997 Mar 1;89(5):1787-92
references.pmid: 9057664