Subarachnoid Bupivacaine in Obese Patients Undergoing Cesarean Delivery
Condition: Anesthesia, Obstetrical
Study type: Interventional
Phase: Phase 4

Summary: 
      This study evaluates the effect of subarachnoid hyperbaric bupivacaine on mean arterial blood
      pressure (MAP) of pregnant patients with obesity undergoing cesarean section half of the
      patients will receive subarachnoid hyperbaric bupivacaine at a dose of 5 mg while the other
      half will receive a dose of 10 mg
    

Detailed description: 
      Once the patients were admitted to the toco-surgery work area, patients over 18 years of age
      were captured, with pregnancy ≥37 weeks of gestation, which, based on weight and height prior
      to pregnancy, obesity is diagnosed with a BMI ≥30 kg / m2 and that had an indication of
      termination of pregnancy via abdominal caesarean section without compromising fetal
      well-being. Specifically, the objectives of the study protocol, benefits and risks were given
      and it was given to choose an envelope containing the consent letter under information, the
      data collection sheet and the group to which it was assigned. He was granted the consent
      letter under information to sign; the same procedure was performed with the husband or
      relative responsible for the patient They underwent pre-anesthetic evaluation, background
      check and review of laboratory tests, as well as taking vital signs such as non-invasive
      blood pressure, mean blood pressure (PAM), O2 saturation and heart rate, Fetal heart rate was
      taken with adult stethoscope. The administration of Hartmann solution at 10ml /kg
      pregestational weight and premedication with ranitidine 50 mg and metoclopramide 10 mg was
      informed prior to admission to the operating room In the operating room, room preparation was
      carried out with material for anesthesiology corresponding laryngoscope, intubation cannulas,
      oropharyngeal cannulas, verification of operation of anesthesia machine, verification of
      material of blocking equipment, needles, syringes, alcohol and iodo povidone; Verify
      hyperbaric bupivacaine drugs, ephedrine and atropine. In case of requiring a change in
      anesthetic technique, general anesthesia have necessary fentanyl opioid drugs, propofol
      inducer and rocuronium muscle relaxant. Preparation of emergency drugs atropine and ephedrine
      dilution of 1 ampoule in 10 ml of diluent solution. The patient was transferred to the
      operating room, baseline vital signs were taken, non-invasive blood pressure, MAP, O2
      saturation and heart rate with the monitor team Simultaneously fetal heart rate was taken
      Permeability of peripheral pathways was verified The patient was placed in a sitting position
      and started with mixed technique neuraxial anesthetic anesthetic technique (placement of
      peridural catheter + subarachnoid block with brand blocking equipment) The anatomical
      reference of the intervertebral space L2-L3, L3-L4 was located in a seated position. Aseptic
      and antiseptic technique was performed with iodo povidone, and subsequently removed with
      alcohol Sterile fields were placed Skin and subcutaneous tissue were infiltrated with 2%
      lidocaine 5 ml of the selected intervertebral space Tuohy needle No. 17 was introduced with
      the "Gout of Gutierrez" technique, until the location was found, it was corroborated with the
      "resistance loss" technique. Through the Tuohy needle, the spinal needle "whitacre" pencil
      No. 27 was introduced until cerebrospinal fluid (CSF) was obtained. The dose of hyperbaric
      bupivacaine blockade of 10 mg (2 ml) or mg (1 ml) was administered agreement with the
      assigned group, in approximately 20 seconds; the spinal needle pencil tip "whitacre" and an
      epidural catheter was introduced with cephalic direction and left 5 cm inside the epidural
      space, left inert. Catheter was attached to the back with adhesive tape The patient was
      placed in a dorsal recumbent position with a shifting wedge placement on the right hip
      approximately 15 degrees to the left. Vital signs monitoring was started every 3 minutes for
      the first 15 minutes and then every 5 minutes until the end of the anesthetic procedure When
      obtaining PAM record of less than 20% at baseline, ephedrine 10 mg is administered and total
      doses required were recorded until PAM records were recovered above 20% of baseline. Together
      with the record of the first taking of vital signs, the fetal heart rate was taken again
      After the second vital signs were taken, (3 minutes), a sensory block evaluation was started
      with a puncture technique from the dermatome where the block was placed and the ascending
      dermatome was registered where the patient reported pain. This assessment was performed every
      3 minutes for the first 15 minutes, and then every 15 minutes until the end of the surgery.
      The blocking level was considered adequate to initiate the surgical procedure when the loss
      of sensitivity in the T4 dermatome was reached. After the second vital signs were taken (3
      minutes), a motor block assessment with a Bromage scale was initiated, in which the patient
      was instructed to make movements with her legs to assess the capacity of movement that still
      remains. This assessment was performed every 3 minutes for the first 15 minutes, and then
      every 15 minutes until the end of the surgery After the second vital signs were taken (3
      minutes), the patient was asked if she had a feeling of nausea or the presence of vomiting
      and was registered. At the extraction of the fetus, the Apgar assessment granted by the
      attached neonatology doctor at one minute and at 5 minutes of extrauterine life was recorded.
      Once the placenta was illuminated, a sample was taken for gasometry with a heparinized
      syringe of the umbilical artery and sent to the laboratory for processing. A dose of local
      anesthetic was administered via a 5% lidocaine 2% peridural catheter if necessary, when the
      patient reported discomfort or pain (referred to the decrease in sensory block) and the
      surgical procedure has not been completed. The time at which subsequent doses are
      administered is recorded The information collected was recorded on the data collection sheet.
      The presence of adverse reactions to drugs or the anesthetic technique were recorded in the
      adverse event sheets. The sample size was calculated with a formula for comparison of two
      means with finite population.

      No results are found in previous publications with a statistically significant P, so a pilot
      test is carried out based on the specified criteria, which includes 30 patients, 15 patients
      in the group administered 5 mg of Subarachnoid hyperbaric bupivacaine and 15 patients in the
      group who were administered 10 mg of the same drug, and a standard deviation of 14.46 was
      obtained for the maximum blood hypotension variable recorded. For the development of the
      finite population formula, the total of anesthesiology procedures is quantified, the total of
      cesarean surgeries performed in the operating rooms of the toco-surgery of the Civil Hospital
      of Guadalajara Fray Antonio Alcalde in 2015; where a total of 1,218 caesarean sections are
      obtained y Calculated losses 25% pregnant women with obesity per group N = 40 patients. The
      statistical analysis was carried out once both study groups were completed. The groups were
      divided with the assignment codes to group 5 or 10. The database was formed in the Microsoft
      Office Excel 2013 program, which was exported to the statistical program Statistics Product
      and Service Solution (SPSS) version 22 in order to carry out the data analysis. All patients
      were included in the statistical analysis. The data obtained are expressed through measures
      of central tendency and dispersion, mean and standard deviation for quantitative variables,
      and frequencies and percentages in the case of qualitative variables. Due to the sample size,
      it is decided to use non-parametric tests for data analysis. The intra-group differences for
      the quantitative variables were determined by the Wilcoxon rank test, while the differences
      between the groups were determined with the Mann Whitney U test. Qualitative variables were
      analyzed through the Chi Square test. A value of p≤0.05 was considered statistically
      significant.
    

Intervention name(s): Bupivacaine 5 mg; Bupivacaine 10 mg
Intervention type(s): Drug; Drug
Intervention description(s): Receive subarachnoid hyperbaric bupivacaine at a dose of 5 mg; Receive subarachnoid hyperbaric bupivacaine at a dose of 10 mg
Other intervention name(s): hyperbaric bupivacaine 1ml; bupivacaine/Dextrose 1ml; hyperbaric bupivacaine 2 ml; bupivacaine/Dextrose 1 ml
Intervention MeSH terms: Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Clinical trial open controlled parallel randomized simple
Masking: Double (Participant, Investigator)
Primary purpose: Supportive Care
Keywords: Bupivacaine; Obesity; Pregnant; Subarachnoid; Cesarean; Subdural