Changes in superior mesenteric artery blood flow after oral, enteral, and parenteral feeding in humans.
OBJECTIVE
Alterations in splanchnic blood flow cause gut ischemia and may predispose to gut-derived sepsis. Increases in superior mesenteric artery (SMA) blood flow occur follow the oral ingestion of food, but the effects of enteral nutrition (EN) on splanchnic perfusion are poorly defined and those of parenteral nutrition (PN) are unknown in humans. The aim of this study was to investigate changes in SMA flow in healthy controls and patients receiving adjuvant nutrition.


METHODS
Qualitative before-after study.


METHODS
Intensive care and general wards at Scarborough Hospital, Scarborough, United Kingdom.


METHODS
Fourteen healthy volunteers and 20 consecutive hemodynamically stable patients receiving adjuvant nutrition.


METHODS
Oral, EN, or PN after an overnight fast.


RESULTS
Duplex ultrasonography was used to assess SMA flow after an overnight fast. Subjects were then rescanned 3 hrs later after commencement of the appropriate test feed so that postprandial flows could be determined. Of the 20 patients recruited, 10 were receiving EN (120 kcal) and 10 PN (175 kcal). Of the 14 volunteers, three received no feed before their second scan (controls), six received an oral meal (530 kcal), and five received EN (120 kcal). Changes in SMA flow within groups were assessed. The control (fasting) volunteers showed no change between the two scans (p = 1.000). All subjects fed intraluminally demonstrated significant increases in postprandial SMA blood flow. Conversely, all patients fed parenterally showed decreased postprandial SMA flows with a median (interquartile range) fasting SMA flow of 14.5 (4.8-24.8) mL/sec, which decreased to 6.1 (2.4-9.2) mL/sec postprandially (p = 0.013).


CONCLUSIONS
Splanchnic flow is modulated by the route of feeding. The clinical significance of these findings requires further investigation as they may be important in the management of the critically ill patient, particularly in those with cardiovascular instability or any patient predisposed to gut ischemia.
Gatt
Marcel
M
The Combined Gastroenterology Research Unit, Scarborough Hospital, Scarborough, United Kingdom.
MacFie
John
J
Anderson
Alexander D G
AD
Howell
Gareth
G
Reddy
Bala S
BS
Suppiah
Aravind
A
Renwick
Ian
I
Mitchell
Charles J
CJ
D000328:Adult; D000368:Aged; D004435:Eating / Q000502:physiology*; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D008297:Male; D017538:Mesenteric Artery, Superior / Q000502:physiology* / Q000503:physiopathology; D008875:Middle Aged; D010288:Parenteral Nutrition; D012039:Regional Blood Flow