Perioperative plasma endothelin-1 and Big endothelin-1 concentrations in elderly patients undergoing major surgical procedures.
Plasma concentrations of the vasoconstrictor endothelin-1 (ET-1) increase during acute physiologic stress, but the role of ET-1 in the pathophysiology of stress remains largely undefined. Whether ET-1 mediates thermoregulatory changes in vasomotor tone is unknown. ET-1 and its more stable precursor, Big ET-1, were measured in plasma obtained at several perioperative time points from 95 consecutive elderly patients (mean age 70 +/- 1 yr) randomized to receive either normothermic or hypothermic perioperative care while undergoing major surgical procedures. In the postoperative period, there were no significant changes in plasma ET-1 concentrations, but Big ET-1 concentrations increased considerably (P < 0.0001). There were no significant differences in mean ET-1 or Big ET-1 levels in normothermic and hypothermic patients. Preoperative and postoperative ET-1 concentrations were significantly higher in patients with a history of hypertension (P < 0.002) and in those requiring treatment for postoperative hypertension (P < 0.003). Patients with cancer and those undergoing abdominal surgery had significantly higher Big ET-1 concentrations (P < 0.0001 and P < 0.003, respectively). These data support the hypothesis that Big ET-1 is a more sensitive measure of endothelin system activation after major surgery. Premorbid conditions and location and type of surgery influence perioperative ET-1/Big ET-1 concentrations.


CONCLUSIONS
The endothelin response seems to be significantly associated with perioperative hemodynamic aberrations. The endothelin-1 (ET-1) precursor Big ET-1 is a more sensitive measure of the endothelin system activation in response to surgical stress than ET-1 alone. Thermoregulatory vasoconstriction in response to mild perioperative hypothermia occurs independently of the endothelin system.
Nelson
J B
JB
Department of Urology and Oncology, The Johns Hopkins University Medical Institutions, Baltimore, Maryland 21224, USA.
Opgenorth
T J
TJ
Fleisher
L A
LA
Frank
S M
SM
D000005:Abdomen / Q000601:surgery; D000367:Age Factors; D000368:Aged; D017558:Elective Surgical Procedures; D019332:Endothelin-1 / Q000097:blood*; D016232:Endothelins / Q000097:blood*; D006439:Hemodynamics; D006801:Humans; D009369:Neoplasms / Q000601:surgery; D011184:Postoperative Period; D011498:Protein Precursors / Q000097:blood*; D012737:Sex Factors
D019332:Endothelin-1; D016232:Endothelins; D011498:Protein Precursors