Prediction of Hypotension During Cesarean Delivery Using Positional Change of Hemodynamic Parameters
Condition: Cesarean Section; Hypotension; Anesthesia, Spinal; Heart Rate; Blood Pressure
MeSH terms: Hypotension
Study type: Observational

Summary: 
      This was a prospective observational study between January 2022 and June 2022. The
      investigators included parturients aged 18 to 45 years, consenting, classified ASA II and
      III, scheduled for elective or emergency cesarean section (Lucas III-IV). Baseline
      hemodynamic parameters were measured in 3 different positions: sitting, supine, and left
      lateral tilt 15°. The investigators defined Δ1 as the change from the sitting position to the
      supine position ad Δ2 as the change from the left lateral tilt 15° position to the supine
      position. Our primary endpoint was the incidence of hypotension defined as a decrease of more
      than 20% from baseline values. The investigators performed univariate and then multivariate
      analysis.
    

Detailed description: 
      The investigators conducted a monocentric prospective observational study between January
      2022 and June 2022, in the maternity unit of Mongi Slim University Hospital in Tunisia. The
      investigators aimed to have a population that is representative of all parturients scheduled
      for cesarean section, thereby they included American Society of Anesthesiologists physical
      status I and II parturients aged 18 to 45 at term and scheduled for either elective cesarean
      section or emergency cesarean section (Lucas III-IV).

      The investigators chose hypotension as the primary endpoint, defined as a decrease in SAP of
      more than 20% of the baseline values. Secondary endpoints included total dose of ephedrine,
      incidence of symptomatic hypotension defined as hypotension plus nausea and/or vomiting
      and/or dizziness, time to onset of hypotension, duration of hypotension, and the use of
      rescue bolus of norepinephrine.

      The investigators tried to standardize the anesthetic management. Parturients were monitored
      with a three-lead electrocardiogram, non-invasive arterial pressure, pulse oximetry, and
      capnography through a facial mask. Baseline maternal hemodynamic parameters were measured 3
      times at 1-minute interval in three different positions: consecutively sitting position,
      supine position, and left lateral tilt 15° position. Spinal anesthesia was performed in the
      sitting position in the L3-L4 or L4-L5 vertebral interspace. Patients received doses of local
      anesthetic weighted to their height. Patients were co-loaded with an infusion of normal
      saline using a pressurized bad. Hypotension was treated with IV bolus of ephedrine in
      increments of 6 mg. If hypotension persisted or reoccurred after the patient had already
      received 60 mg of ephedrine, The investigators resorted to rescue bolus of norepinephrine in
      increments of 5 µg. After child delivery, patients received a standard dose of 10 IU of
      oxytocin, additional doses were added if the obstetrician requested it.

      The investigators collected data regarding demographic characteristics, obstetric
      characteristic, anesthetic management, and details about the hypotensive event.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        During the study recruitment period, there were three hundred and thirty-one parturients
        eligible for recruitment. One hundred and eighty-eight cases were not included and
        twenty-one were excluded, leaving one hundred and twenty-one women who were recruited.

        Patients were divided into 2 groups according to the primary endpoint of the study:

          -  Group Normotension: 41 parturients.

          -  Group Hypotension: 80 parturients.