The effects of vasoactive agents on flow through saphenous vein grafts during lower-extremity peripheral vascular surgery.
OBJECTIVE
The purpose of this study was to assess the effects of hemodynamic alterations on vein graft flow during peripheral vascular surgery. It was hypothesized that vasopressors can be administered without compromising flow through the vein grafts.


METHODS
Tertiary care center, university medical center.


METHODS
Randomized placebo-controlled double-blinded study.


METHODS
The effects of phenylephrine, epinephrine, milrinone, intravenous fluid, and placebo on newly constructed peripheral vein grafts were assessed in 60 patients (12 patients in each of 5 groups). Systemic and central hemodynamics were measured by using intra-arterial and pulmonary artery catheters. Vein graft flow was measured by using a transultrasonic flow probe (Transultrasonic Inc, Ithaca, NY).


RESULTS
Phenylephrine increased systemic mean blood pressure (mBP) (68.2-94.0 mmHg, p < 0.01), systemic vascular resistance (SVR) (1,091-1,696 dynes x sec x cm(-5), p < 0.001), and vein graft flow (39.5-58.9 mL/min, p < 0.01), whereas cardiac output remained unchanged. Epinephrine resulted in increased cardiac output (4.4-6.9 L/min, p < 0.01) and mBP (72.7-89.1 mmHg, p < 0.01), whereas vein graft flow was reduced in 6 of 12 patients. Intravenous fluid administration resulted in a relatively smaller increase in graft flow (37.6-46.0 mL/min, p < 0.05), an increase in cardiac output, and an insignificant decrease in SVR. Other treatments had either little or no effect on vein graft flow.


CONCLUSIONS
The study hypothesis was partly supported. Although both phenylephrine and epinephrine increased blood pressure, only the former increased vein graft flow in all patients. In conjunction with increases in graft flow after fluid administration, these data suggest that factors affecting vein graft flow are not just simply related to systemic hemodynamics.
Maslow
Andrew D
AD
Department of Anesthesiology, Rhode Island Hospital, Providence, RI, USA. amaslow@rcn.com
Bert
Arthur
A
Slaiby
Jeffrey
J
Carney
William
W
Marcaccio
Edward
E
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004311:Double-Blind Method; D004837:Epinephrine / Q000494:pharmacology; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply*; D008875:Middle Aged; D020105:Milrinone / Q000494:pharmacology; D016491:Peripheral Vascular Diseases / Q000601:surgery*; D010656:Phenylephrine / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects*; D012501:Saphenous Vein / Q000637:transplantation*; D014655:Vascular Resistance / Q000187:drug effects
D010656:Phenylephrine; D020105:Milrinone; D004837:Epinephrine