title: Catecholamine release during laparoscopic fundoplication with high and low doses of remifentanil.
abstract: BACKGROUND
  Reports on stress responses to laparoscopic surgery have been conflicting. Depth of anesthesia may influence the neuro-hormonal release, including catecholamines. Opioids depress general sympathetic activation in a dose-dependent manner. We investigated the hypothesis that remifentanil would depress the catecholamine response to pneumoperitoneum and laparoscopic surgery differently with a high dose (HD) compared with a low dose (LD).
  
  
  METHODS
  In a randomized, prospective study we investigated 18 ASA I-II patients undergoing laparoscopic fundoplication with an intra-abdominal pressure of 12 mmHg. The patients were randomized to receive either a LD (0.13 microg kg-1x min-1) or HD (0.39 microg kg-1 x min-1) of remifentanil with a target-controlled infusion (TCI) technique. Bispectral index of EEG (BIS) was maintained at 40-55 by propofol delivered by a TCI system. Arterial catecholamines were analyzed at different times during the procedure.
  
  
  RESULTS
  Norepinephrine increased equally in both groups during pneumoperitoneum and surgical intervention. Epinephrine stayed low in the HD-group, while increasing during surgery in the LD-group.
  
  
  CONCLUSIONS
  High dose of remifentanil depressed the epinephrine response to pneumoperitoneum and surgery, indicating no general activation of the sympathetic nervous system. Neither a LD nor HD of remifentanil depressed the norepinephrine response during pneumoperitoneum. This suggests a centrally independent release of norepinephrine.
authors.affiliation: Department of Anesthesiology, Ullevål University Hospital, Oslo, Norway. kirsti.myre@ioks.uio.no
authors.forename: K
authors.initials: K
authors.lastname: Myre
authors.forename: J
authors.initials: J
authors.lastname: Raeder
authors.forename: M
authors.initials: M
authors.lastname: Rostrup
authors.forename: T
authors.initials: T
authors.lastname: Buanes
authors.forename: O
authors.initials: O
authors.lastname: Stokland
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000378:metabolism*; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D018662:Fundoplication; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000008:administration & dosage; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects; D015742:Propofol; D011446:Prospective Studies; D000077208:Remifentanil; D012121:Respiration, Artificial; D013312:Stress, Physiological / Q000378:metabolism
chemical_list: D018686:Anesthetics, Intravenous; D002395:Catecholamines; D010880:Piperidines; D000077208:Remifentanil; D015742:Propofol