Clinical trial NCT04082676: Height Versus Height and Weight Based Spinal Bupivacaine on Maternal Haemodynamics for Elective Cesarean in Short Stature Patients
Official title: Effect of Height Versus Height and Weight Based Intrathecal Bupivacaine Dose on Maternal Haemodynamics for Elective Caesarean Section in Short Stature Patients: A Randomized Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Maternal Hypotension After Spinal Anesthesia
Lead sponsor: B.P. Koirala Institute of Health Sciences
Sponsor class: OTHER
First posted: 2019-09-09
Enrollment: 112
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Doses of intrathecal bupivacaine based on patients either height or height and weight has shown to lower the risk of maternal hypotension with similar quality of anesthesia compared to conventional doses.

In clinical practice there is a tendency of reducing the dose of bupivacaine as either low fixed dose or using the doses based on either height and weight or height (0.06mg/cm) alone in parturient with short stature. However, there is lack of evidence regarding the appropriate dose required in this group of patients. Therefore, our aim is to compare the height versus height and weight based intrathecal bupivacaine dose for elective caesarean on maternal haemodynamics in short stature patients.

Detailed description: Spinal induced hypotension in women undergoing caesarean section (CS) is the most common unwanted effect. The dose of intrathecal local anesthetic is the main determining factor that balances between successful block and an incidence of maternal hypotension. Although lowering the doses of intrathecal bupivacaine provides better maternal hemodynamic stability it compromises the quality of anesthesia. Moreover, there is no consensus regarding the cut-off at which the dose can be defined as low. Doses based on patients either height or height and weight has shown to lower the risk of maternal hypotension with similar quality of anesthesia compared to conventional doses.

In clinical practice there is a tendency of reducing the dose of bupivacaine as either low fixed dose or using the doses based on either height and weight or height (0.06mg/cm) alone in parturient with short stature. However, there is lack of evidence regarding the appropriate dose required in this group of patients.

Our aim is to compare the height versus height and weight based intrathecal bupivacaine dose for elective caesarean on maternal haemodynamics in short stature patients.

Doses of intrathecal bupivacaine for elective caesarean section based on Harten chart is available from the following reference- Harten JM, Boyne I, Hannah P, Varveris D, Brown A. Effects of a height and weight adjusted dose of local anaesthetic for spinal anaesthesia for elective Caesarean section. Anaesthesia 2005; 60: 348-53.

Consent for the participation in the study will be obtained during pre-anaesthetic assessment visits in the evening before surgery. The investigator will also educate the patients regarding the use of numeric rating scale scores. Preoperative anxiety will be recorded in numerical rating scale scores where 0 is no anxiety and 10 is maximum anxiety patient reported. The enrolled subjects will be randomly assigned to 2 equal groups (allocation ratio, 1:1) according to the codes generated from the website (www.sealedenvleop.com) using the variable block size of 4, 6 and 8. The group allocation will be concealed in sequentially numbered, sealed opaque envelopes that will be opened by the anaesthesia assistant not involved in the study only after the patient arrives in the operating room. The patient will be fasted for at least eight hours and will receive antibiotics, ranitidine 50 mg and metoclopramide 10 mg intravenously via 18-gauge cannula before transfer to the operation room. In the operating table patient will be laid supine with a wedge under right buttock and standard monitors (electrocardiography, pulse oximetry, and noninvasive BP) will be applied. Thereafter, successive three readings of heart rate (HR) and systolic blood pressure (SBP) will be taken at 2 minutes interval with difference not exceeding 10%. The average of these recordings will be documented by the investigators as baseline parameters. To maintain blinding, the investigator will leave the operating room and will return immediately once the spinal injection is initiated. Subarachnoid block will be performed by the attending anesthesiologist not involved in the study in the sitting position at the L3-L4 or L4-L5 vertebral interspace using a 25-gauge spinal needle via midline approach. The study solution will be administered according to the group allocated. In Group A the dose of heavy bupivacaine will be based on height and weight and in group B the dose will be based on patient's height (0.06 mg/cm). 10 microgram fentanyl will be added to bupivacaine in both groups.

Eligibility criteria: Inclusion Criteria:

* Women with full-term gestation undergoing planned Caesarean section under spinal anesthesia
* Who provide consent .
* Height less than 150 cm

Exclusion Criteria:

* Patients with height \<140 cm,
* Hypertensive disorders of pregnancy,
* Placental disorders,
* Body mass index ≥ 40 kg/m2,
* Diabetes mellitus
* Cardiovascular
* Cerebrovascular
* Hormonal disorder
* Renal disease
* Polyhydramnios
* Known case of bad obstetric history
* Fetal abnormalities
* Baseline systolic blood pressure (SBP) less than 100 mmHg
* Contraindication to spinal anaesthesia
* Allergy to any drug used in the study and
* Those unable to understand and sign the consent form

Primary outcomes:
measure: Incidence of post-spinal hypotension
timeFrame: Up to delivery of baby
Secondary outcomes:
measure: Incidence of post-delivery hypotension
timeFrame: Up to end of surgery
measure: Incidence of post-spinal hypotension
timeFrame: Up to delivery of baby
measure: Incidence of post-delivery hypotension
timeFrame: Up to end of surgery
measure: Lowest systolic blood pressure
timeFrame: Up to end of surgery
measure: Vasopressor requirement
timeFrame: Up to end of surgery
measure: Incidence of bradycardia
timeFrame: Up to end of surgery
measure: Incidence of nausea vomiting
timeFrame: Up to end of surgery
measure: Incidence of shivering
timeFrame: Up to end of surgery
measure: Intraoperative analgesia requirement
timeFrame: Up to end of surgery
measure: Systolic blood pressure
timeFrame: Up to end of surgery
measure: Quality of anaesthesia
timeFrame: At 1 to 2 hours in Post anesthesia care unit
measure: quality of operating condition
timeFrame: Up to end of surgery
measure: Intraoperative sedation
timeFrame: Up to end of surgery
measure: Maternal satisfaction with intraoperative anesthesia for cesarean delivery
timeFrame: up to 1-2 hours stay Post anesthesia care unit
measure: Incidence of pruritus
timeFrame: Up to end of surgery
measure: Duration of pain free period
timeFrame: up to 24 h after surgery
measure: Incidence of dizziness
timeFrame: up to end of surgery
measure: Time to sensory block reached to 6th thoracic dermatome
timeFrame: Up to 10 min from injection of spinal anesthesia
measure: Maximum level of sensory block reached
timeFrame: Up to end of surgery
measure: Time to sensory block regressed to 10th thoracic dermatome
timeFrame: Up to 24 hour after surgery
measure: Time to complete motor blockade
timeFrame: Upto 15 min after spinal anesthesia
measure: Time to motor blockage regression
timeFrame: Up to 24 hour after surgery
measure: Apgar score
timeFrame: 5 and 10 minutes after delivery
Other outcomes:
Locations:
city: Dharān Bāzār
country: Nepal
facility: BP Koirala Institute of Health Sciences (BPKIHS)
state: Koshi
Study officials:
affiliation: B.P. Koirala Institute of Health Sciences
name: Asish Subedi, MD
role: PRINCIPAL_INVESTIGATOR
References: