title: Free Fatty acids and delayed cerebral ischemia after subarachnoid hemorrhage.
abstract: OBJECTIVE
  The purpose of this study was to understand factors related to increases in serum free fatty acid (FFA) levels and association with delayed cerebral ischemia (DCI) after subarachnoid hemorrhage.
  
  
  METHODS
  We performed serial measurement of systemic oxygen consumption by indirect calorimetry and FFA levels by liquid chromatography/mass spectrometry in the first 14 days after ictus in 50 consecutive patients with subarachnoid hemorrhage. Multivariable generalized estimating equation models identified associations with FFA levels in the first 14 days after SAH and Cox proportional hazards model used to identified associations with time to DCI.
  
  
  RESULTS
  There were 187 measurements in 50 patients with subarachnoid hemorrhage (mean age, 56±14 years old; 66% women) with a median Hunt-Hess score of 3. Adjusting for Hunt-Hess grade and daily caloric intake, n-6 and n-3 FFA levels were both associated with oxygen consumption and the modified Fisher score. Fourteen (28%) patients developed DCI on median postbleed Day 7. The modified Fisher score (P=0.01), mean n-6:n-3 FFA ratio (P=0.02), and mean oxygen consumption level (P=0.04) were higher in patients who developed DCI. In a Cox proportional hazards model, the mean n-6:n-3 FFA ratio (P<0.001), younger age (P=0.05), and modified Fisher scale (P=0.004) were associated with time to DCI.
  
  
  CONCLUSIONS
  Injury severity and oxygen consumption hypermetabolism are associated with higher n-FFA levels and an increased n-6:n-3 FFA ratio is associated with DCI. This may indicate a role for interventions that modulate both oxygen consumption and FFA levels to reduce the occurrence of DCI.
authors.affiliation: Neurological Institute of New York, 177 Fort Washington Avenue, New York, NY 10032, USA. nb2217@columbia.edu
authors.forename: Neeraj
authors.initials: N
authors.lastname: Badjatia
authors.forename: David
authors.initials: D
authors.lastname: Seres
authors.forename: Amanda
authors.initials: A
authors.lastname: Carpenter
authors.forename: J Michael
authors.initials: JM
authors.lastname: Schmidt
authors.forename: Kiwon
authors.initials: K
authors.lastname: Lee
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Mayer
authors.forename: Jan
authors.initials: J
authors.lastname: Claassen
authors.forename: E Sander
authors.initials: ES
authors.lastname: Connolly
authors.forename: Mitchell S
authors.initials: MS
authors.lastname: Elkind
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D002545:Brain Ischemia / Q000097:blood* / Q000209:etiology; D002153:Calorimetry, Indirect; D002851:Chromatography, High Pressure Liquid; D003625:Data Collection; D003627:Data Interpretation, Statistical; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D015525:Fatty Acids, Omega-3 / Q000097:blood; D043371:Fatty Acids, Omega-6 / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D009752:Nutritional Status; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012372:ROC Curve; D013345:Subarachnoid Hemorrhage / Q000097:blood* / Q000150:complications; D020301:Vasospasm, Intracranial / Q000150:complications / Q000628:therapy
chemical_list: D005230:Fatty Acids, Nonesterified; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D010100:Oxygen