title: Transient mesenteric ischaemic episodes tracked by continuous jejunal PCO2 monitoring during liquid feeding.
abstract: OBJECTIVE
  To test the effect of liquid feeds on the responses to splanchnic ischaemia of a continuous rapid response PCO2 sensor inserted in the jejunum.
  
  
  METHODS
  Prospective experimental animal study in a university research laboratory.
  
  
  METHODS
  Adult male Wistar rats.
  
  
  METHODS
  Adult male Wistar rats (285-425 g) were anaesthetised with sodium pentobarbitone 60 mg/kg i.p. and ventilated with 100% oxygen and isoflurane via tracheostomy to a PaCO2 of 30-40 mmHg. A sensor was inserted into the mid-jejunum to record PCO2 every second. Distal aortic pressure was transduced. Four control rats received no feeds whilst in another four rats liquid feed was infused into the proximal jejunum at 3 ml/h. In each rat five episodes of splanchnic ischaemia were induced by 2-min elevations of an aortic sling to a mean distal aortic pressure of 30 mmHg.
  
  
  RESULTS
  PCO2 elevations were always detectable, usually less than a minute from the onset of splanchnic ischaemia in both fed and unfed rats, with no difference in mean times to detectable response. In the fed rats there was a small but significant increase in the time to peak sensor response (196+/-16 vs. 180+/-12 s) and a trend towards an elevated mean baseline luminal PCO2 (67+/-9 vs. 55+/-4 mmHg).
  
  
  CONCLUSIONS
  Brief episodes of splanchnic ischaemia were tracked successfully by a rapid response jejunal continuous PCO2 sensor during the infusion of a proprietary liquid feed preparation despite minor changes in PCO2 response characteristics and a possible elevation in baseline luminal PCO2.
authors.affiliation: Division of Anesthesiology and Intensive Care, Royal Brisbane Hospital, Herston Road, Herston, Queensland 4029, Australia. thomas_morgan@health.qld.gov.au
authors.forename: T J
authors.initials: TJ
authors.lastname: Morgan
authors.forename: B
authors.initials: B
authors.lastname: Venkatesh
authors.forename: G P
authors.initials: GP
authors.lastname: Bawa
authors.forename: D M
authors.initials: DM
authors.lastname: Purdie
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001784:Blood Gas Analysis / Q000295:instrumentation / Q000379:methods*; D002245:Carbon Dioxide / Q000097:blood; D004567:Electrodes, Implanted; D004750:Enteral Nutrition / Q000009:adverse effects*; D006801:Humans; D007413:Intestinal Mucosa / Q000098:blood supply / Q000378:metabolism; D007511:Ischemia / Q000175:diagnosis* / Q000209:etiology; D007583:Jejunum / Q000098:blood supply* / Q000378:metabolism; D008297:Male; D010313:Partial Pressure; D051381:Rats; D017208:Rats, Wistar; D013152:Splanchnic Circulation
chemical_list: D002245:Carbon Dioxide