Distal vs proximal popliteal sciatic nerve block in foot/ankle surgery for morbidly obese

Study Type: Therapy
OE Level of Evidence: 2
Journal Level of Evidence: N/A
Synopsis
60 severely and morbidly obese patients scheduled for unilateral foot or ankle surgery were randomized to an ultrasound-guided popliteal sciatic nerve blockade either proximal or distal to the branching point of the sciatic nerve. The purpose of this study was to compare the two block administration sites in terms of pain scores, block onset characteristics, and complications. Outcomes were assessed Please login to view the rest of this report. Please login to view the rest of this report.
Funding: Industry funded
Sponsor: Pacira Pharmaceuticals (Parsippany, NJ)
Conflicts: None disclosed
CONTENT IS LOCKED
Why was this study needed now?
Obesity is often an exclusion criterion for studies pertaining to local anesthetic administration due to difficulty in anatomical navigation and location of nerves through adipose tissue, resulting in concerns for unsuccessful nerve blockage. Nerve block administration for patients undergoing foot or ankle surgery is commonly placed proximal to the sciatic nerve bifurcation, but better visual acuity distal to the bifurcation suggests that the nerve block may be more successful when placed distal to the bifurcation as an alternative for patients with obesity. Current evidence on analgesic effects in patients with severe and morbid obesity are extremely rare, thus warranting the present study.
What was the principal research question?
In the management of patients with severe and morbid obesity undergoing unilateral foot or ankle surgery, does ultrasound-guided popliteal nerve block administration distal to the sciatic bifurcation provide better outcomes with regards to pain, block onset, and complications when compared to administration proximal to the bifurcation?
Population: 60 patients, 18 years of age or older, with severe and morbid obesity undergoing unilateral foot or ankle surgery.
Intervention: Distal group: patients received an ultrasound-guided popliteal sciatic nerve blockade distal to the sciatic nerve bifurcation site. (n=30, 30 analyzed; Mean age: 49.07+/-8.94; 27F/3M)
Comparison: Proximal group: patients received an ultrasound-guided popliteal sciatic nerve blockade proximal to the sciatic nerve bifurcation site. (n=30, 28 analyzed; Mean age: 54.47+/-12.17; 23F/5M)
Outcomes: The primary outcome was pain assessed on a numeric rating scale (NRS; 0-10 from no pain to worst pain) in the post-anesthesia care unit (PACU). Secondary outcomes were the onset of the sensorimotor block, the need to convert to general anesthesia, block procedural times, and narcotic analgesic use.
Methods: RCT; patient & assessor blinded
Time: Outcomes were assessed perioperatively.
What were the important findings?
What should I remember most?
How will this affect the care of my patients?
The authors responsible for this critical appraisal and ACE Report indicate no potential conflicts of interest relating to the content in the original publication.