Neuraxial Anaesthesia: Does BMI Relate to Ease of Neuraxial Anaesthesia?

Obesity Clinical Trial

Official title:

Neuraxial Anaesthesia: Does BMI Relate to Palpability of Bony Landmarks and Are Standard Needles a Suitable First Choice in Patients With BMI>30kg/m2

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT03315845
• Other study ID #: NationalMHI
• Status: Not yet recruiting
• Phase: N/A
• First received: October 17, 2017
• Last updated: October 22, 2017
• Start date: October 23, 2017
• Est. completion date: January 9, 2018

Study information

• Verified date: October 2017
• Source: National Maternity Hospital, Ireland
• Contact: Moninne Creaney, MBBChBAOFCAI
• Phone: 00353879837656
• Email: creaneym[@]hotmail.com
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Neuraxial anaesthesia can be more difficult and associated with more complications if the patient's bony landmarks are difficult to palpate. They are more likely to be difficult to palpate if a patient has a high Body Mass Index (BMI), (>30kg/m2). The depth that the spinal or epidural needle must be inserted is usually longer in these patients with high BMIs. We wish to palpate the backs of at least 100 such patients to see how many of them have impalpable bony landmarks. We then wish to use ultrasound to measure the distance from skin to the posterior epidural complex to discover if this length is longer than the standard needle length. If it is longer in the majority of people we study, we will recommend changing standard practice to start using a longer needle for all first attempts at neuraxial anaesthesia in this patient population.

Description:

Complications rates including failure are higher in obese patients undergoing anaesthesia procedures. Anaesthetists have adopted the use of ultrasound to assist in overcoming these difficulties. Neuraxial ultrasound is proving to be beneficial in those patients in whom identification of interspinous spaces is difficult and most of these patients are obese.

In our institution, there is a 'standard practice' for neuraxial procedures, with a 'standard' needle used for first attempts (Whitacre 25G 90mm for spinal, Tuohy 18G 80mm for epidural). If the operator has not reached the desired space (spinal or epidural) with the needle inserted to 8cm, a longer needle is then considered for further attempts. This exposes the patient to at least one extra neuraxial needle insertion. Studies have shown that increased needle insertions and redirections are associated with increased complications.

We hypothesised that a large number of patients with BMI>30kg/m2 would have a depth of spinal/epidural space that is greater than the length of the 'standard' needle used. Therefore we suggest that practice should change to use the longer needle or a combined spinal-epidural on the first attempt in these patients.

To test our hypothesis, we will assess the ease of palpation of the following anatomical landmarks: anterior and posterior iliac crests; lumbar spinous processes; scapulae; and sacral cornua. We will then perform neuraxial sonography of the lumbar spine, measuring depth to epidural space. Finally we will measure waist circumference in those patients with BMI <30kg/m2.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 100
• Est. completion date: January 9, 2018
• Est. primary completion date: January 9, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 16 Years and older

Eligibility

Inclusion Criteria:

• Recorded BMI >30kg/m2; ability to give consent; non-emergency cases.

Exclusion Criteria:

• Previous metal work to lumbar spine.

Related Conditions & MeSH terms

• Neuraxial Ultrasound
• Obesity
• Obstetric Anaesthesia

Intervention

Other:
• Palpation of bony landmarks for neuraxial anaesthesia.
Manual palpation of anterior and posterior iliac crests; lumbar spinous processes; scapulae; and sacral cornua. Ultrasound of neuraxial anatomy to assess depth to epidural space.

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
National Maternity Hospital, Ireland

References & Publications (8)

Ansari T, Yousef A, El Gamassy A, Fayez M. Ultrasound-guided spinal anaesthesia in obstetrics: is there an advantage over the landmark technique in patients with easily palpable spines? Int J Obstet Anesth. 2014 Aug;23(3):213-6. doi: 10.1016/j.ijoa.2014.03.001. Epub 2014 Mar 12. — View Citation

Arzola C, Mikhael R, Margarido C, Carvalho JC. Spinal ultrasound versus palpation for epidural catheter insertion in labour: A randomised controlled trial. Eur J Anaesthesiol. 2015 Jul;32(7):499-505. doi: 10.1097/EJA.0000000000000119. — View Citation

Balki M, Lee Y, Halpern S, Carvalho JC. Ultrasound imaging of the lumbar spine in the transverse plane: the correlation between estimated and actual depth to the epidural space in obese parturients. Anesth Analg. 2009 Jun;108(6):1876-81. doi: 10.1213/ane.0b013e3181a323f6. — View Citation

Carnie J, Boden J, Gao Smith F. Prediction by computerised tomography of distance from skin to epidural space during thoracic epidural insertion. Anaesthesia. 2002 Jul;57(7):701-4. — View Citation

Gnaho A, Nguyen V, Villevielle T, Frota M, Marret E, Gentili ME. Assessing the depth of the subarachnoid space by ultrasound. Rev Bras Anestesiol. 2012 Jul;62(4):520-30. doi: 10.1016/S0034-7094(12)70150-2. — View Citation

Grau T, Leipold RW, Delorme S, Martin E, Motsch J. Ultrasound imaging of the thoracic epidural space. Reg Anesth Pain Med. 2002 Mar-Apr;27(2):200-6. — View Citation

Seligman KM, Weiniger CF, Carvalho B. The Accuracy of a Handheld Ultrasound Device for Neuraxial Depth and Landmark Assessment: A Prospective Cohort Trial. Anesth Analg. 2017 Aug 30. doi: 10.1213/ANE.0000000000002407. [Epub ahead of print] — View Citation

Srinivasan KK, Lee PJ, Iohom G. Ultrasound for neuraxial blockade. Med Ultrason. 2014 Dec;16(4):356-63. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Palpability of bony landmarks for neuraxial anaesthesia	The percentage of patients with BMI>30kg/m2 who have difficult or impalpable bony landmarks including: lumbar spinous processes; anterior and posterior iliac spines; scapulae; and sacral cornua.	4 months
Secondary	Ultrasonographic distance from skin to posterior epidural complex	To use sonography to measure the distance from skin to the dural complex in these patients and quantify the percentage whose distance is greater than the length of the standard needle.	4 months