Norepinephrine in low to moderate doses may not increase luminal concentrations of L-lactate in the gut in patients with septic shock.
OBJECTIVE
To investigate the effect of different doses of norepinephrine (noradrenaline) on luminal concentrations of L-lactate in the rectum and stomach in patients with fluid-resuscitated septic shock.


METHODS
This was a paired cross-over study in which the dose of norepinephrine was titrated to mean arterial blood pressures (MAPs) of 65 and 85 mmHg in random sequence. It was performed in a mixed intensive care unit at a university hospital. Eight patients with fluid-resuscitated septic shock requiring norepinephrine (>0.1 microg/kg/min) were included. Patients were treated with norepinephrine to a MAP of either 65 or 85 mmHg for 2 h. After a 'washout' period of 2 h, the dose of norepinephrine was titrated to the other endpoint of MAP for another 2 h. The concentrations of L-lactate in the rectal and gastric lumen were estimated by 1-h equilibrium dialysis during the second hour of the treatment periods.


RESULTS
MAP and central venous oxygen saturation were increased by increasing the dose of norepinephrine [median (range) (microg/kg/min): 0.07 (0.00-0.60) and 0.18 (0.11-1.00) at MAPs of 65 and 85 mmHg, respectively], whereas the metabolic markers were unaffected [luminal concentrations (mmol/l) of L-lactate in the rectum of 1.9 (0.8-6.4) and 1.8 (0.9-5.7) (P =0.94) and in the stomach of 1.1 (0.1-10.0) and 1.3 (0.3-9.7) (P =0.88) at MAPs of 65 and 85 mmHg, respectively].


CONCLUSIONS
In this small study, luminal concentrations of L-lactate in the rectum and stomach were unaffected by norepinephrine at low to moderate doses. These data suggest that norepinephrine may not increase luminal concentrations of l-lactate in the gut in patients with fluid-resuscitated septic shock.
Ibsen
M
M
Department of Intensive Care 4131, Rigshospitalet, Blegdamsvej 9, DK-2199 Copenhagen, Denmark.
Jørgensen
V L
VL
Perner
A
A
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage* / Q000494:pharmacology; D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D005440:Fluid Therapy; D005753:Gastric Mucosa / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019344:Lactic Acid / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000008:administration & dosage* / Q000494:pharmacology; D012007:Rectum / Q000378:metabolism; D012772:Shock, Septic / Q000378:metabolism*; D018709:Statistics, Nonparametric
D000316:Adrenergic alpha-Agonists; D019344:Lactic Acid; D009638:Norepinephrine