The effect of propofol on the grading of diastolic function: a prospective observational study

Abstract

Abstract Background Left ventricular diastolic dysfunction accounts for approximately half the cases of heart failure in the community. Its strong association with both peri-operative and post-operative adverse outcomes in both non-cardiac and cardiac surgical patients highlights the importance of accurately measuring diastolic function peri-operatively. Previous studies examining general anesthesia and diastolic function have shown varying impacts of propofol, ranging from improvement to no effect or worsening of diastolic function. This study aimed to evaluate the impact of propofol and mechanical ventilation on left ventricular diastolic function assessment by comparing pre-induction to post-induction measurements. Methods This was an analysis of a subset of data from a prospective, observational, single-center study. Written informed consent was obtained from patients who were at least 18 years of age and undergoing elective, non-cardiac surgery with planned use of intra-arterial blood pressure monitoring. After routine pre-medication (midazolam, 1-2 mg IV) was administered, diastolic function was assessed using trans-thoracic echocardiography (TTE). The following parameters were obtained: lateral mitral annular tissue doppler velocity (e’), peak early mitral flow velocity (E) and peak late mitral flow velocity (A). Five minutes after induction of anesthesia with propofol and initiation of mechanical ventilation, a repeat TTE was performed. Using the simplified algorithm described by Swaminathan et al., the diastolic measurements were analyzed, and the patient was assigned a grade. Results Data for analysis was available from 113 patients. All values are presented as median [95%CI]. There were significant decreases in e’ (9.1 [8.7, 10.5] to 8.2 [7.2, 8.9] cm/s) {p < 0.0001}, E (79.8 [76.0, 83.4] to 66.0 [62.8, 72.0] cm/s) {p < 0.0001}, and A (82.2 [75.3, 89.0] to 64.1 [60.2, 69.0] cm/s) {p < 0.0001}. 49 patients (43%) had a change in their diastolic function grades from pre-induction to post-induction. Of those 49 patients, 20 (41%) had an improvement, while 29 (59%) had a worsening of their diastolic function grade. Patients with a lower e’ pre-induction value or a higher E/e’ pre-induction ratio were more likely to have an improved post-induction diastolic function grade. Conclusion The induction of general anesthesia with propofol has a significant effect on the assessment of diastolic function. Propofol may either improve or worsen the diastolic function grading. The changes in diastolic grading may be related to the pre-induction e’ and E/e’ values. Trial registration The study was registered on the clinicaltrial.gov website (NCT04177225).

Keywords

• Diastolic function
• Propofol
• General anesthesia
• Tissue doppler imaging
• Mitral flow velocity