The degree of inibition of sympathetic activity by local anesthetics in epidural anesthesia in patients with coronary artery disease

Abstract

The aim – to assess the influence of local anesthetics (LA) on vegetative balance using dynamics of the sympathovagal index and pNN50.Material and Methods. Were examined 124 males who underwent surgery due to inguinal hernia under epidural anesthesia with status 1 or 2 according to the American Society of Anesthesiologists. The average age of patients was (52.4 ± 1.2) years, height 160– 194 cm, body mass index <40 kg/m2. All patients in the perioperative period were examined using daily ECG-monitoring with determining heart rate variability.Results. In patients without coronary artery disease (CAD). during the active period (AP) of monitoring the LF/HF ratio was the highest in the lidocaine group (3.22 ± 0.18), the lowest – in the bupivacaine group (3.01 ± 0.25), the ropivacaine group had an intermediate value (3.15 ± 0.23). In the passive period (PP) a decrease of LF/HF was observed in all groups: in the group of lidocaine – by 36.65%, in the group of ropivacaine – by 24.44% and in the bupivacaine group – by 19.93%. pNN50 in the AP was the highest in the group of lidocaine (25.88 ± 3.63), the lowest – in the group of ropivacaine (22.72 ± 3.82), an intermediate value had the group of bupivacaine (23.14 ± 3.16). In PP the pNN50 values were increased in all groups, most pronounced in the group of lidocaine and bupivacaine (36.55% and 31.76%, respectively), less pronounced – in the ropivacaine group (5.28%). In patients with CAD in the AP of monitoring the LF/HF ratio was the highest in the bupivacaine group (3.13 ± 0.24), the lowest – in patients of the ropivacaine group (2.98 ± 0.26); patients of the lidocaine group had an intermediate values (3.01 ± 0.26). In the PP of monitoring in the group of lidocaine and bupivacaine we observed a decrease of the LF/HF value by 9.30% and 17.57% respectively, but in the group of ropivacaine the LF/HF value remained at the baseline. PNN50 in the AP was the highest in the group of lidocaine (21.31 ± 5.15), the lowest – in the bupivacaine group (15.01 ± 3.17) and in the middle – in the ropivacaine group (19.18 ± 3.36). In the PP the pNN50 values increased in all groups of patients, the most in the group of bupivacaine (16.52%), then in the lidocaine group (12.62%) and the least in the group of ropivacaine (11.57%).Conclusions. Ropivacaine, based on the significantly lower compared to other LA level of sympathicotonia in the AP of observation, has a less pronounced proarhythmogenic properties. Using the ropivacaine compensatory potential of the parasympathetic nervous system in the AP of the observation is the most optimal. The increase of the tone of the parasympathetic branch of autonomous nervous system, based on the dynamics of the pNN50 parameters, is more significant during a treatment with lidocaine; ropivacaine in this situation has advantages over bupivacaine. Thus, the property of compensatory increase in activity of the parasympathetic part of autonomous nervous system (in a response to the increased sympathetic tone) is best expressed with lidocaine and ropivacaine. At the same time, the risk of hemodynamic disorders (due to a significant increase in parasympathetic tone during the PP) is the highest among persons who had lidocaine and bupivacaine as a LA. Ropivacaine, taking into the account its effect on the optimal vegetative balance in patients with CAD, can be recomended as the drug of a choice for epidural anesthesia during surgical interventions for inguinal hernias.