Myocardial injury is decreased by late remote ischaemic preconditioning and aggravated by tramadol in patients undergoing cardiac surgery: a randomised controlled trial☆

Abstract

The purpose of this study was to test, whether the late phase of remote ischaemic preconditioning (L-RIPC) improves myocardial protection in coronary artery bypass grafting (CABG) with cold-crystalloid cardioplegia and whether preoperative tramadol modifies myocardial ischaemia-reperfusion injury using the same group of patients in a single-blinded randomized controlled study. One hundred and one adult patients were randomly assigned to either the L-RIPC, control or tramadol group. L-RIPC consisted of three five-minute cycles of upper limb ischaemia and three five-minute pauses using blood pressure cuff inflation 18 hours prior to the operation. Patients in the tramadol group received 200 mg tramadol retard at 19:00 hours, the day before the operation and at 06:00 hours. Serum troponin I levels were measured at eight, 16 and 24 hours after surgery. Myocardial samples for inducible and endothelial nitric oxide synthases (iNOS, eNOS) estimation were drawn twice: before and after cannulation for cardiopulmonary bypass from the auricle of the right atrium. We found that L-RIPC can reduce injury beyond the myocardial protection provided by cold-crystalloid cardioplegia, and tramadol worsened myocardial injury after CABG. Expressions of iNOS were increased in the control (significantly) and L-RIPC groups and dampened in the tramadol group.

Experimental cardiovascular and lung research Remote ischemic preconditioning versus standard myocardial protection in cardiac surgery: ten years of clinical trials. A systematic review and meta-analysis

“…Subgroup analysis of the studies reporting outcomes of CABG with or without AVR showed results consistent with the general trend (SMD -0.42; 95% CI: -0.70 to -0.13, p = 0.005) and I 2 = 67% [9,[20][21][22][23][24][25][26][27]. Studies concerning isolated valvular surgery did not confirm the protective result of rIPC; however, heterogeneity (I 2 = 94%) was essentially influencing the outcome effect under the random [28][29][30].…”

“…Finally, fifteen papers were found to present the best available evidence. These studies pertained to: adult coronary bypass grafting surgery with or without AVR [9,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], adult valvular surgery [28][29][30], and pediatric cardiac surgery [31][32][33]. All the available papers were designed as prospective randomized controlled trials.…”

“…Male gender proportion ranged from 35% to 100% in the rIPC group and from 28% to 100% among the controls. The majority of patients were operated on due to coronary artery disease (335 in the rIPC group and 340 in the control group) [9,[20][21][22][23][24][25][26][27]. The analysis of rIPC in pediatric patients undergoing cardiac surgery included 67 patients in the rIPC study groups and 70 in the control groups [31][32][33], whereas 89 and 90 patients were submitted to isolated valvular surgery with or without rIPC, respectively [28][29][30].…”

“…All studies were proof-of-concept trials with small sample sizes, and only three included more than 100 patients [20][21][22]. Diabetic subjects were partially included in six trials [9,[21][22][23][24]30]. Time from rIPC to global ischemia (e.g.…”

Limb Ischemic Preconditioning for Open Heart Surgery in Infants

“…In previous similar adult study protocols, cuffs have been inflated to 200 or 40 mmHg above the patients' actual upper arm blood pressure [2,3]. Tourniquet pressures may cause complications such as soft tissue blisters, burns, rashes, abrasions, nerve-related injuries, and muscle injuries [4]. Lieberman et al [5] recommended that a cuff pressure of 50 mmHg above systolic blood pressure is sufficient to provide limb ischemia in pediatric patients.…”