title: The effect of low body mass index on outcome in critically ill surgical patients.
abstract: BACKGROUND
  Body mass index (BMI) has been correlated with complications and outcome in surgical patients at the two extremes of the nutrition spectrum.
  
  
  OBJECTIVE
  To study the relationship between BMI, outcome, hospital length of stay, and complications in patients admitted to the surgical intensive care unit (SICU).
  
  
  METHODS
  Review of prospectively acquired data in SICU patients. Data acquired included weight, height, age, gender, Acute Physiology and Chronic Health Evaluation (APACHE) II-III scores, Simplified Acute Physiology II (SAPS II) scores, and morbidity and mortality. Patients who stayed in the unit <24 hours were excluded.
  
  
  RESULTS
  Of 793 patients, 706 had a normal BMI (NBMI; mean 22.12 kg/m²) and 87 were underweight (UBMI; mean 16.81 kg/m²). There was no statistically significant difference in APACHE II-III and SAPS scores. The NBMI group had more infections, and the UBMI group had more pulmonary complications (χ(2), P < .0087). There was no significant difference in acute respiratory distress syndrome, atrial fibrillation, myocardial infarction, septicemia, or ventilator- associated pneumonia (Fisher exact test, P = 0.38; χ(2), P = .41). The ICU length of stay between the 2 groups was not significantly different (6.7 vs 5.8 days; P = .64). Overall, there was 11.1% (88/793) SICU mortality; 74 of 706 (10.5%) patients expired in the NBMI group, and 14 of 87 (16.1%) patients expired in the UBMI group.
  
  
  CONCLUSIONS
  Low BMI is associated with increased mortality in SICU patients. A BMI <18.5 kg/m² is an independent factor affecting outcome in surgical critical care patients.
authors.affiliation: North Shore Long Island Jewish Health System, Glen Oaks, NY 11004, USA. drrgupta@hotmail.com
authors.forename: Rajeev
authors.initials: R
authors.lastname: Gupta
authors.forename: Denis
authors.initials: D
authors.lastname: Knobel
authors.forename: Vikraman
authors.initials: V
authors.lastname: Gunabushanam
authors.forename: Emanuel
authors.initials: E
authors.lastname: Agaba
authors.forename: Gary
authors.initials: G
authors.lastname: Ritter
authors.forename: Corrado
authors.initials: C
authors.lastname: Marini
authors.forename: Rafael
authors.initials: R
authors.lastname: Barrera
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D016638:Critical Illness / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007239:Infections / Q000453:epidemiology / Q000209:etiology*; D007362:Intensive Care Units; D007902:Length of Stay; D008171:Lung Diseases / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality*; D015995:Prevalence; D011446:Prospective Studies; D012016:Reference Values; D013851:Thinness / Q000150:complications* / Q000453:epidemiology