title: The impact of admission diagnosis on gastric emptying in critically ill patients.
abstract: BACKGROUND
  Disturbed gastric emptying (GE) occurs commonly in critically ill patients. Admission diagnoses are believed to influence the incidence of delayed GE and subsequent feed intolerance. Although patients with burns and head injury are considered to be at greater risk, the true incidence has not been determined by examination of patient groups of sufficient number. This study aimed to evaluate the impact of admission diagnosis on GE in critically ill patients.
  
  
  METHODS
  A retrospective review of patient demographics, diagnosis, intensive care unit (ICU) admission details, GE, and enteral feeding was performed on an unselected cohort of 132 mechanically ventilated patients (94 males, 38 females; age 54 +/- 1.2 years; admission Acute Physiology and Chronic Health Evaluation II [APACHE II] score of 22 +/- 1) who had undergone GE assessment by 13C-octanoic acid breath test. Delayed GE was defined as GE coefficient (GEC) of less than 3.20 and/or gastric half-emptying time (t50) of more than 140 minutes.
  
  
  RESULTS
  Overall, 60% of the patients had delayed GE and a mean GEC of 2.9 +/- 0.1 and t50 of 163 +/- 7 minutes. On univariate analysis, GE correlated significantly with older age, higher admission APACHE II scores, longer length of stay in ICU prior to GE measurement, higher respiratory rate, higher FiO2 (fraction of inspired oxygen), and higher serum creatinine. After these factors were controlled for, there was a modest relationship between admission diagnosis and GE (r = 0.48; P = 0.02). The highest occurrence of delayed GE was observed in patients with head injuries, burns, multi-system trauma, and sepsis. Delayed GE was least common in patients with myocardial injury and non-gastrointestinal post-operative respiratory failure. Patients with delayed GE received fewer feeds and stayed longer in ICU and hospital compared to those with normal GE.
  
  
  CONCLUSIONS
  Admission diagnosis has a modest impact on GE in critically ill patients, even after controlling for factors such as age, illness severity, and medication, which are known to influence this function.
authors.affiliation: Department of Gastroenterology, Royal Adelaide Hospital, Adelaide, Australia. namphoung28@hotmail.com
authors.forename: Nam Q
authors.initials: NQ
authors.lastname: Nguyen
authors.forename: Mei P
authors.initials: MP
authors.lastname: Ng
authors.forename: Marianne
authors.initials: M
authors.lastname: Chapman
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Fraser
authors.forename: Richard H
authors.initials: RH
authors.lastname: Holloway
mesh_terms: D018806:APACHE; D000367:Age Factors; D002056:Burns / Q000503:physiopathology; D006259:Craniocerebral Trauma / Q000503:physiopathology; D003404:Creatinine / Q000097:blood; D016638:Critical Illness / Q000145:classification*; D005260:Female; D005746:Gastric Emptying; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D012121:Respiration, Artificial; D012189:Retrospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000503:physiopathology
chemical_list: D003404:Creatinine