title: Gastric emptying following brain injury: effects of choice of sedation and intracranial pressure.
abstract: OBJECTIVE
  To compare the effects of opioid and non-opioid sedation on gastric emptying.
  
  
  METHODS
  Prospective, randomized trial.
  
  
  METHODS
  University teaching hospital ICU.
  
  
  METHODS
  21 brain injured patients requiring sedation, mechanical ventilation and intracranial pressure (ICP) monitoring for > 24 h.
  
  
  METHODS
  Patients were randomized to receive infusions of either morphine plus midazolam (M), or propofol (P). Gastric emptying was assessed by the paracetamol absorption technique and by residual volumes following a 200 ml test feed.
  
  
  RESULTS
  Pre-sedation Glasgow Coma Score, mean ICP and the presence of bowel sounds were noted. Plasma concentrations of paracetamol were measured over 3 h following a 1 g gastric dose. There were no differences in median peak paracetamol concentration (M, 18.5 versus P, 20.8 mg/l), median time to peak concentration (M, 20 versus P, 25 min), median area under the concentration-time curve (AUC), or in the median residual volumes at 1 h (M, 14 versus P, 10.5 ml) and 2 h (M, 5 versus P, 3 ml). In patients with ICP > 20 mmHg, paracetamol concentrations were lower (p < 0.05), and AUC after 30 min was lower (165 mg.min/l versus 411 mg.min/l, p = 0.023). Mean ICP was correlated with AUC (Kendall rank p = 0.027). Gastric emptying did not correlate with initial Glasgow Coma Score or presence of bowel sounds.
  
  
  CONCLUSIONS
  Gastric emptying is not improved in patients with brain injury by avoiding morphine (1-8 mg/h) in the sedative regimen. Intracranial hypertension is associated with reduced gastric emptying.
authors.affiliation: Department of Anaesthesia and Intensive Care, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: C J
authors.initials: CJ
authors.lastname: McArthur
authors.forename: T
authors.initials: T
authors.lastname: Gin
authors.forename: I M
authors.initials: IM
authors.lastname: McLaren
authors.forename: J A
authors.initials: JA
authors.lastname: Critchley
authors.forename: T E
authors.initials: TE
authors.lastname: Oh
mesh_terms: D000082:Acetaminophen / Q000493:pharmacokinetics; D000328:Adult; D001930:Brain Injuries / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology*; D016292:Procedural Sedation / Q000379:methods*; D004359:Drug Therapy, Combination; D005260:Female; D005746:Gastric Emptying / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D008874:Midazolam / Q000494:pharmacology; D008875:Middle Aged; D009020:Morphine / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology; D015742:Propofol / Q000494:pharmacology; D011446:Prospective Studies; D011559:Pseudotumor Cerebri / Q000209:etiology / Q000503:physiopathology*
chemical_list: D006993:Hypnotics and Sedatives; D009294:Narcotics; D000082:Acetaminophen; D009020:Morphine; D008874:Midazolam; D015742:Propofol