Læknablaðið - 15.12.1989, Blaðsíða 4

LÆKNABLAÐIÐ
NÝR DOKTOR í LÆKNISFRÆÐI -
JÓNAS MAGNÚSSON
Nýlega lauk Jónas Magnússon læknir
doktorsprófi frá Háskólanum í Lundi.
Ritgerðin nefnist á frummálinu: »Secretion
and Hypoglycemic Action of Insulin after
Surgery. Effects of epidural anaesthesia,
enteral nutrition and subtotal pancreatectomy«.
Hér á eftir fer útdráttur úr ritgerðinni:
The hypoglycemic action and secretion of
insulin was analyzed in 96 elderly patients
before, during, one day after, and four days
after minor to major abdominal surgery.
The effects of general anaesthesia, epidural
analgesia, enteral nutrition and subtotal
pancreatic resection were studied. The
hypoglycemic effect of insulin was measured
after a brief infusion of insulin and the
secretion of insulin was determined after
infusion of 25 g glucose.
Surgery of various degree was followed by
insulin resistance and glucose intolerance
with no change in early insulin release and
unchanged or increased late insulin response.
Epidural analgesia was associated with
preserved insulin sensitivity during minor
lower body surgery but was ineffective in
maintaining insulin sensitivity after major
abdominal surgery. On the other hand epidural
analgesia was effective in maintaining glucose
tolerance and insulin secretion after major
abdominal surgery. Enteral nutrition was
associated with unchanged insulin sensitivity,
glucose tolerance and insulin secretion
after colorectal surgery. Subtotal pancreatic
resection resulted in a severe reduction of
insulin secretion, a decrease in glucagon
levels, a preserved hypoglycemic effect of
insulin and unchanged glucose tolerance.

Jónas Magnússon
Conclusions: The glucose intolerance after
surgery depends solely on impaired insulin
sensitivity. Epidural anaesthesia is able to
preserve insulin action following minor
surgical procedures but is ineffective in
maintaining insulin sensitivity one day
after major surgery, a situation in which
insulin secretion and glucose tolerance was
maintained. During enteral nutrition insulin
action and glucose tolerance were maintained.
The unchanged insulin sensitivity and glucose
tolerance after pancreatic resection depended
at least partly on reduction in pancreatic
glucagon.