Propofol Induction's Effect on Cardiac Function
Condition: This Study Was Focused to Evaluate Feasibility of Doppler Tissue Monitoring During the Induction Anesthesia,; and Evaluate Routine Propofol Induction's Effect on Myocardial Tissue Motion, Using Non-invasive Doppler Tissue and 2D Speckle Tracking Imaging.; This is the First Study, to Our Knowledge, Which Has Evaluated the Possible Impact of Propofol Induction on LV Function.
Study type: Observational

Summary: 
      Background: Propofol effects dose-dependent myocardial depression, but there is little
      clinical data available regarding the direct impact of propofol induction on myocardial
      function.

      Objectives: The purpose of this study was to examine the impact of propofol-based anesthesia
      induction on cardiac function in low-risk patients.
    

Detailed description: 
      Study population After approval by the institutional ethics committee and written informed
      consent, we prospectively enrolled adult patients who were scheduled for elective non-cardiac
      surgery. During the preoperative anesthesia visit, we selected patients with low-risk as
      indicated by the revised cardiac risk index of 0 and normal LV function (ejection fraction ≥
      60% and septal e' ≥ 8 cm/s). We excluded patients with an arrhythmia, poor lateral axis in
      supine position, regional wall motion abnormality, or other structural heart diseases.
      Patients with any of the following conditions were also excluded: unfavorable airway or
      facemask fit, intractable coughing, hiccups, or hypotension (mean BP < 60 mmHg) requiring IV
      positive inotropes or vasoconstrictors during the study period.

      Anesthesia induction Upon each patient's arrival at the holding area, we placed an 18-gauge
      IV line in the right forearm vein and administered 10 mL/kg/hour of lactated Ringer's
      solution, 0.2 mg of glycopyrrolate, and 0.03 mg/kg of midazolam, as a premedication. Once in
      the operation room, we started to monitor electrocardiography, non-invasive BP, HR, pulse
      oximeter oxygen saturation, and the bispectral index (BIS). Anaesthesia induction was started
      in the following manner. Patients took a spontaneous respiration with inspired oxygen (8
      L/min) through a transparent facemask and a circulation system with a reservoir bag. Bolus
      propofol (2.0 mg/kg) was administered intravenously for 10 seconds, after which assisted
      ventilation followed. After 5 minutes, complete induction was confirmed via a lack of
      train-of-four response and followed by tracheal intubation for maintenance anesthesia.

      Intraoperative transthoracic echocardiography: Imaging After positioning the patient supine
      on the operation table, serial transthoracic echocardiography was performed with a portable
      GE Vivid Q platform (General Electric, Milwaukee, WI), before (T0) and 1, 3, and 5 minutes
      after the propofol bolus injection (T1, T2 and T3, respectively) along with hemodynamic
      recordings at the same time (BP, HR, and BIS). Two-dimensional imaging of parasternal and
      apical views and pulsed wave (PW) Doppler imaging of mitral inflow & LV outflow were
      performed. DTI was recorded at both septal and lateral mitral annulus from the apical
      4-chamber view to determine longitudinal endocardial velocities with a sweep of 66.7 mm/s.
      Each set of images required less than 30 seconds.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Study population After approval by the institutional ethics committee and written informed
        consent, we prospectively enrolled adult patients who were scheduled for elective
        non-cardiac surgery. During the preoperative anesthesia visit, we selected patients with
        low-risk as indicated by the revised cardiac risk index of 0 and normal LV function
        (ejection fraction ≥ 60% and septal e' ≥ 8 cm/s. We excluded patients with an arrhythmia,
        poor lateral axis in supine position, regional wall motion abnormality, or other structural
        heart diseases. Patients with any of the following conditions were also excluded:
        unfavorable airway or facemask fit, intractable coughing, hiccups, or hypotension (mean BP
        < 60 mmHg) requiring IV positive inotropes or vasoconstrictors during the study period.
      
Keywords: Propofol, Induction anesthesia, Doppler tissue imaging