title: Ultrasound-guided popliteal sciatic nerve blockade in the severely and morbidly obese: a prospective and randomized study.
abstract: Limited research data exist regarding optimal block techniques in the severely and morbidly obese patient population. We compared two approaches to sciatic nerve blockade at the popliteal fossa in severely and morbidly obese patients. The purpose of this study was to identify differences in pain scores, block onset characteristics, and adverse events between the proximal (prebifurcation) and the distal (postbifurcation) sites.
  
  
  
  Patients with a body mass index ≥35 scheduled for unilateral foot surgery with a popliteal block were randomized to receive an ultrasound-guided popliteal block proximal or distal to the bifurcation of the sciatic nerve. The primary endpoint was numerical rating scale (NRS) scores in the post anesthesia care unit (PACU).
  
  
  
  Thirty patients were enrolled in each group for a total of 60 participants. Patients in the distal group had lower NRS scores upon entry into the PACU (0.70 ± 1.91) compared with the proximal group (2.17 ± 3.37), had a faster onset of sensorimotor blockade, and were less likely to require a repeat block procedure, conversion to general anesthesia, or local anesthetic supplementation by the surgical team. There was no difference in block procedure times or incidence of nerve injury between the two groups.
  
  
  
  The distal approach to the popliteal block provided several intraoperative and analgesic benefits without a difference in block procedural times in the severely and morbidly obese. It is a cost-free intervention that results in a higher likelihood of a successful block in a population where avoidance of opioids is desirable.
authors: Department of Anesthesiology, Ochsner Clinic Foundation, 1514 Jefferson Highway, New Orleans, LA, 70121, USA. jsoberon@ochsner.org.
authors: José R
authors: 0000-0002-9914-9838
authors: JR
authors: Soberón
authors: Department of Anesthesiology, Ochsner Clinic Foundation, 1514 Jefferson Highway, New Orleans, LA, 70121, USA.
authors: Carrie
authors: C
authors: McInnis
authors: Department of Anesthesiology, Ochsner Clinic Foundation, 1514 Jefferson Highway, New Orleans, LA, 70121, USA.
authors: Kim S
authors: KS
authors: Bland
authors: The Johns Hopkins Hospital, Baltimore, MD, USA.
authors: Allison L
authors: AL
authors: Egger
authors: Ochsner Clinic Foundation, Department of Anesthesiology, The University of Queensland School of Medicine, Ochsner Clinical School, New Orleans, LA, USA.
authors: Matthew E
authors: ME
authors: Patterson
authors: Ochsner Clinic Foundation, Department of Anesthesiology, The University of Queensland School of Medicine, Ochsner Clinical School, New Orleans, LA, USA.
authors: Clint E
authors: CE
authors: Elliott
authors: Department of Orthopedic Surgery, Ochsner Clinic Foundation, New Orleans, LA, USA.
authors: Robert J
authors: RJ
authors: Treuting
authors: Ochsner Clinic Foundation, Department of Anesthesiology, The University of Queensland School of Medicine, Ochsner Clinical School, New Orleans, LA, USA.
authors: Kristie
authors: K
authors: Osteen
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D000779:Anesthetics, Local / Q000008:administration & dosage; D000842:Ankle / Q000601:surgery; D015992:Body Mass Index; D023381:Endpoint Determination; D005260:Female; D005528:Foot / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D009767:Obesity, Morbid / Q000000981:diagnostic imaging*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000453:epidemiology / Q000517:prevention & control; D011446:Prospective Studies; D012584:Sciatic Nerve / Q000000981:diagnostic imaging* / Q000293:injuries; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000779:Anesthetics, Local
keywords: Foot (or) ankle surgery; Postoperative pain; Regional anesthesia; Sciatic (or) popliteal block; Severe (or) morbid obesity