Cardiac effects of high thoracic epidural anaesthesia during bicycle exercise: an echocardiographic study

There are several studies on the effect of thoracic epidural anaesthesia on left ventricular (LV) function, but the results are controversial 5, 6, 7, 8. These studies were performed in baseline conditions, where cardiac sympathicotonus is low and sympathicolysis by TEA might not be that influential. The influence of upper TEA on circulation during physical exercise has already been tested 9, 10, but these studies used questionable study designs (repeated exercise tests) and the executed echocardiographic exam was very limited. Furthermore, the influence of upper TEA on the performance of the right ventricle (RV) under physical exercise has not been evaluated. Recently, Rex and colleagues 11 demonstrated that in pigs TEA strongly inhibited the positive inotropic response of the RV to acute pulmonary hypertension, suggesting an important role for sympathetic nervous system. Reason for us to conduct a study that non-invasively evaluates the effects of TEA on biventricular systolic and diastolic function during exercise by using pulsed wave tissue Doppler imaging. We hypothesize that the circulatory and cardiac effects of TEA will be most pronounced during circumstances of increased sympathicotonus, which will be induced by an exercise test on a bicycle.

We hypothesize that the circulatory and cardiac effects of TEA will be most pronounced during circumstances of increased sympathicotonus, which will be induced by an exercise test on a bicycle.

Eighteen patients scheduled for thoracic surgery (full lateral thoracotomies or pleurodesis by video-assisted thoracoscopic surgery/VATS) under thoracic epidural anaesthesia (TEA) and general anaesthesia will be assigned randomly to one of the two study arms. The randomization will be performed using a computer generating a randomization list.
After epidural administration of either NaCl 0,9 % or ropivacaine 0.75 % patients will perform an exercise test on a bicycle. Each patient will perform this exercise test at two different time periods:



Test period 1: Day before surgery.
Test period 2: Immediately before surgery.

In study arm A, the patient will receive an epidural dose of 6 ml of NaCl 0.9 % in period 1 and 6 ml of ropivacaine 0.75 % in period 2. In study arm B patients receive an epidural dose 6 ml of ropivacaine 0.75 % in period 1 and 6 ml of NaCl 0.9% in period 2. Patient and investigators will not be blinded to the epidural study medication.


T0 baseline = before epidural injection of ropivacaine/NaCl

T1 epidural = 30 minutes after epidural injection of ropivacaine/NaCl

T2 exercise = after 3 minutes bicycling with 20 % of maximal workload

T3 exercise = after 3 minutes bicycling with 40 % of maximal workload

T4 exercise = after 3 minutes bicycling with 60 % of maximal workload

T5 recovery = after 10 minutes recovery of exercise test

Thoracic epidural anaesthesia

Exercise bicycle/stress testing