Effect of remimazolam vs. propofol on hemodynamics during general anesthesia induction in elderly patients: Single-center, randomized controlled trial

The current study aimed to compare the effects between remimazolam and propofol on hemodynamic stability during the induction of general anesthesia in elderly patients.We used propofol at a rate of 60 mg/(kg·h)in the propofol group(group P)or remimazolam at a rate of 6 mg/(kg·h)in the remimazolam group(group R)for the induction.A processed electroencephalogram was used to determine whether the induction was successful and when to stop the infusion of the study drug.We measured when patients entered the operating room(T_(0)),when the induction was successful(T_(1)),and when before(T_(2))and 5 min after successful endotracheal intubation(T_(3)).We found that mean arterial pressure(MAP)was lower at T_(1–3),compared with T_(0) in both groups,but higher at T_(2) in the group R,whileΔMAP_(T0–T2) andΔMAP_(max) were smaller in the group R(ΔMAP_(T0–T2):the difference between MAP at time point T_(0) and T_(2),ΔMAP_(max):the difference between MAP at time point T_(0) and the lowest value from T_(0) to T_(3)).Cardiac index and stroke volume index did not differ between groups,whereas systemic vascular resistance index was higher at T_(1–3) in the group R.These findings show that remimazolam,compared with propofol,better maintains hemodynamic stability during the induction,which may be attributed to its ability to better maintain systemic vascular resistance levels.

Effects of sevoflurane on left ventricular function by speckletracking echocardiography in coronary bypass patients: A randomized trial

The present study aimed to dynamically observe the segmental and global myocardial movements of the left ventricle during coronary artery bypass grafting by transesophageal speckle-tracking echocardiography,and to assess the effect of sevoflurane on cardiac function.Sixty-four patients scheduled for the off-pump coronary artery bypass grafting were randomly divided into a sevoflurane-based anesthesia(AS)group and a propofolbased total intravenous anesthesia(AA)group.The AS group demonstrated a higher absolute value of left ventricular global longitudinal strain than that of the AA group at both T1(after harvesting all grafts and before coronary anastomosis)and T_(2)(30 min after completing all coronary anastomoses)(P<0.05).Moreover,strain improvement in the segment with the highest preoperative strain was significantly reduced in the AS group,compared with the AA group at both T1 and T_(2)(P<0.01).The flow of the left internal mammary artery-left anterior descending artery graft was superior,and the postoperative concentration of troponin T decreased rapidly in the AS group,compared with the AA group(P<0.05).Compared with total intravenous anesthesia,sevoflurane resulted in a significantly higher global longitudinal strain,stroke volume,and cardiac output.Sevoflurane also led to an amelioration in the condition of the arterial graft.Furthermore,sevoflurane significantly reduced strain improvement in the segmental myocardium with a high preoperative strain value.The findings need to be replicated in larger studies.

Bioprosthetic Valve Size Selection to Optimize Aortic Valve ReplacementSurgical Outcome: A Fluid-Structure Interaction Modeling Study

Aortic valve replacement(AVR)remains a major treatment option for patients with severe aortic valve disease.Clinical outcome of AVR is strongly dependent on implanted prosthetic valve size.Fluid-structure interaction(FSI)aortic root models were constructed to investigate the effect of valve size on hemodynamics of the implanted bioprosthetic valve and optimize the outcome of AVR surgery.FSI models with 4 sizes of bioprosthetic valves(19(No.19),21(No.21),23(No.23)and 25 mm(No.25))were constructed.Left ventricle outflow track flow data from one patient was collected and used as model flow conditions.Anisotropic Mooney–Rivlin models were used to describe mechanical properties of aortic valve leaflets.Blood flow pressure,velocity,systolic valve orifice pressure gradient(SVOPG),systolic cross-valve pressure difference(SCVPD),geometric orifice area,and flow shear stresses from the four valve models were compared.Our results indicated that larger valves led to lower transvalvular pressure gradient,which is linked to better post AVR outcome.Peak SVOPG,mean SCVPD and maximum velocity for Valve No.25 were 48.17%,49.3%,and 44.60%lower than that from Valve No.19,respectively.Geometric orifice area from Valve No.25 was 52.03%higher than that from Valve No.19(1.87 cm2 vs.1.23 cm2).Implantation of larger valves can significantly reduce mean flow shear stress on valve leaflets.Our initial results suggested that larger valve size may lead to improved hemodynamic performance and valve cardiac function post AVR.More patient studies are needed to validate our findings.