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Femoral to Radial Artery Pressure Gradient after Cardiopulmonary Bypass in Chronic Users of Oral Vasodilators
Fadia A. Haddad, M.D.; Ghassan T. Sleilaty, M.D.; Alexander G. Yazigi, M.D.; Samia N. Madi-Jebara, M.D.; Gemma N. Hayek, M.D.
Department of Anesthesiology, Hotel-Dieu de France, Beirut, Lebanon

A significant aortic to radial artery pressure gradient may exist during and after cardiopulmonary bypass (CPB) [1]. This gradient has been attributed to the distal arterial vasodilation induced by CPB [2]. Oral calcium channel blockers (CCB) and angiotensin-converting enzyme inhibitors (ACEI) are chronic treatment in patients (pts) scheduled for cardiac surgery.

The aim of this study is to evaluate the effects of these vasodilators on the femoral to radial pressure gradient after CPB.


After institutional approval and written consent, 144 pts scheduled for elective cardiac surgery, under CPB, were included in a prospective study. There were divided into 4 groups (Gr) according to the preoperative treatment. Gr I (n=22): pts treated with CCB; Gr II (n=44): pts treated with ACEI; Gr III (n=15): pts treated with CCB and ACEI; Gr IV (n=63): pts without CCB or ACEI. Preoperative treatment was maintained until surgery. Pts receiving IV vasoactive drugs before CPB were excluded. CPB was performed under hemodilution and normothermia. Radial and femoral pressures were measured via 18G x 8cm catheters. The two catheters were connected by 150cm long tubing to the same pressure transducer. Systolic, mean and diastolic femoral and radial pressures, SVRI and hematocrit (Ht), were recorded prior to CPB, 5,30,60,90,120 minutes and 4,8,12 hours after CPB discontinuation, in the four groups. Results are expressed as mean ± SD. Two Way ANOVA for repeated measurements, t-test and X ² test are used for statistical analysis. p < 0.05 is considered significant.


The four groups were comparable regarding demographic, preoperative and intraoperative data. There was no significant femoral to radial pressure gradient before CPB in any group. As expected, a significant systolic, mean and diastolic pressure gradient was observed in all groups, up to 120 minutes after discontinuation of CPB. There was no statistical difference between these pressure gradients in the four groups, at the different times of measurement (fig 1&2).


A significant femoral to radial pressure gradient exist after CPB. This pressure gradient is not increased nor prolonged by the chronic use of CCB, ACEI, or both, in pts undergoing CPB.


1-Anesthesiology 1992; 77: 63-66

2-Anesthesiology 1995; 62: 557-61

Anesthesiology 2002; 96: A161
Figure 1

Figure 2