Ultrasound Guided Spinal Anesthesia in Non Obese Obstetric Patients

The Use of Ultrasound to Guide Spinal Anesthesia in Obstetrics. Is There an Advantage Over Landmark Technique in Non-obese Patients?

The classical method for spinal anesthesia relies on the use of bony landmarks to identify the level and point of entry of the spinal needle. Over the years, in experienced hands, this method consistently proved to be successful and safe.

The introduction of ultrasound to guide neuraxial anaesthesia into clinical practice was relatively slow compared to peripheral nerve blocks or central venous catheterization. This could be due to the technical difficulties posed by the bony structures surrounding the spinal cord and its dura that blocks the path of the ultrasound beam. Many anesthetists are reluctant to change their conventional landmark technique, particularly with most studies showing no change in the success rate between ultrasound guided and the landmark techniques.

Several studies however showed that the ultrasound guided approach reduces the number of attempts to achieve a successful block and reduces the procedure time particularly in obese patients and those with technical difficulties.

In this study the investigators are trying to answer the following question : Is there any advantage in using ultrasound to guide spinal anaesthesia in non obese obstetric patients with easily palpable bony landmarks?

Study Overview

• Status: Completed
• Conditions: Cesarean Section
• Intervention / Treatment: Procedure: Ultrasound guided spinal anesthesia

Detailed Description

Patients will be randomized using a web based randomization program into two groups: Ultrasound guided spinal anesthesia (US) & conventional spinal anesthesia (C). In both groups, the level of the third or fourth lumbar inter-space (L3/4 or L4/5) will be identified using either ultrasound (transverse and longitudinal approach) or palpation method using anatomical landmarks.

All ultrasound examinations and spinal anesthesia will be performed by 3 anesthetists with experience in ultrasound guided neuraxial block (between 100 and 200 cases). The ultrasound examination will be done using Logiq e TM ultrasound machine (GE Solingen Germany) with 4C RS 2 - 5.5MHz Broadband multi-frequency probe.

The predetermined point of entry for the introducer needle will be marked on the patient's back. The spinal anaesthesia will be administered with the patient in the sitting position, using a 26 gauge pencil point needle (PortexTM) with 15 mg of heavy Bupivacaine and 20 micrograms of Fentanyl. An independent observer, who is blinded to the method used to identify the point of entry of the introducer needle, will be collecting the data.The spinal anesthesia will be labeled as successful if a bilateral block to the sixth thoracic dermatome (T6) , judged by loss of cold and touch discrimination, is established 5 minutes after the spinal injection.

• Study Type: Interventional
• Enrollment (Actual): 150
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Arab Emirates
  • Abu Dhabi, United Arab Emirates, 3788
    • Corniche Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: ADULT; OLDER_ADULT; CHILD
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• All mothers with body mass index (BMI) equal to or less than 35 who has normal singleton pregnancy
• At 37 weeks gestation or more
• Admitted to Corniche Hospital for elective caesarean section under spinal anaesthesia

Exclusion Criteria:

• Patients with BMI >35
• Patieints with difficult anatomical landmarks
• Patients with neurological disease or coagulation defects
• Patients receiving anticoagulants
• Patients refusing spinal anaesthesia

Study Plan

How is the study designed?

Design Details

• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: SINGLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
NO_INTERVENTION: Conventional spinal anesthesia
EXPERIMENTAL: Ultrasound guided spinal anesthesia	Procedure: Ultrasound guided spinal anesthesia; Using the ultrasound to identify the spinal puncture level, mid-line and the depth of the dura.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The number of skin punctures	Number of times the skin is punctured by the introducer needle.	30 minutes
The number of spinal needle passes	The number of times the spinal needle tip is advanced beyond the tip of the introducer needle.	30 minutes
The time of the procedure	From skin puncture by the introducer to viewing cerebro-spinal fluid back-flow at the hub of the spinal needle.	30 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The patient satisfaction with spinal anesthesia	scale 0-10, 0=not satisfied, 10=completely satisfied	24 hours
Backache after spinal needle placement, assessed within 24 hours postoperatively	verbal rating scale(VRS), 0-10, 0=no pain, 10=maximum pain.	24 hours

Collaborators and Investigators

• Sponsor: Corniche Hospital
• Investigators: Principal Investigator: Mounir Fayez, MD, Corniche Hospital; Principal Investigator: Amr Maher, MD, Corniche Hospital; Principal Investigator: Ahmed El Gamassy, MD, Corniche Hospital

Study record dates

Study Major Dates

• Study Start: October 1, 2011
• Primary Completion (ACTUAL): July 1, 2012
• Study Completion (ACTUAL): October 1, 2012

Study Registration Dates

• First Submitted: September 22, 2011
• First Submitted That Met QC Criteria: September 23, 2011
• First Posted (ESTIMATE): September 26, 2011

Study Record Updates

• Last Update Posted (ESTIMATE): March 12, 2013
• Last Update Submitted That Met QC Criteria: March 11, 2013
• Last Verified: March 1, 2013

More Information

Terms related to this study

• Keywords: Ultrasound; Cesarean section; Spinal anesthesia
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: ch3151105