A novel and simple setup for positioning the Lower Extremity Using Commonly Accessible Equipment
Carole Lin MD, Farrukh Munshey MD, Ban C.H. Tsui Dip Eng,BSc(Math),BSc(Pharm), MSc(Pharm), MD, FRCP(C),PG Dip Echo
Proper patient positioning is a critical component for safe and successful performance of ultrasound (US) guided peripheral nerve blocks. Factors such as patient body habitus, decreased mobility and limited access to landmarks can present a challenge to safe and optimal positioning. Specialized commercially available equipment such as the Tereboot (Anesthesia Innovation and Management, USA) was developed to allow access to the posterior compartment of the thigh when performing a supine US guided popliteal nerve block. We report a simple, cost-effective and flexible setup using readily available operating room (OR) equipment to optimally and safely position the lower extremity for performance of sciatic nerve blocks.
Materials and Methods
We utilized a height adjustable Mayo stand, foam head prone pillows, and tilt capabilities of OR tables. With the patient in the supine position, the Mayo stand is placed above the lower extremities so that the most cephalad edge is above the popliteal fossa. Prone foam head pillows were placed so that the cylindrical cavities aligned with the leg and cradled the legs and ankles. Velcro straps were used to secure the foam to the Mayo stand (figure 1). In a neutral supine position, the Mayo stand first was positioned in a range of heights to allow for different degrees of knee flexion. With the Mayo stand set at a desirable height for the lower extremity, the operating table was then tilted laterally to allow external rotation of the lower extremity (figure 2).
With the combined use of adjusting the height difference between the mayo stand and the OR table we were able to achieve 90 degrees of flexion. Tilting the operating room table, we were able to provide external rotation allowing further access to the posterior fossa and in turn the sciatic nerve. This setup allowed for unimpeded US probe manipulation leading to optimal image quality with easily discernable anatomical structures.
We describe an immediate and easily accessible setup which allows optimal positioning for the supine placement of an ultrasound guided popliteal nerve block. All items are readily available and cost effective. The setup is particularly useful for providing leg stability in those with large body habitus and limited mobility. The Mayo stand can be sterilized between cases or draped with a sterile sleeve. Prone foam pillows and straps are disposable. Ease of sterility and usage of disposable equipment aids in reducing the risk of infectious complications from repeat use of equipment. We have begun to routinely utilize this technique when performing a supine US guided popliteal nerve block.
We would like to acknowledge, Ashley Mendoza, a surgical scrub nurse at our institution, who helped in the formation of this setup.