Page 124 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

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Chapter 5
availability of a skilled anesthesiologist or resident.
Before the ultrasound-guided femoral nerve block or FICB was performed, oral informed consent was obtained as part of the standard operating procedure (SOP). No sedative pre- medication was administered prior to the procedure.
The ED SOP was jointly written by anesthesiologists and EPs, in accordance with the exist- ing SOP for ultrasound-guided femoral nerve blocks performed by anesthesiologists in the operating room. It prescribes a sterile procedure and a conservative maximal LA dosage to minimize risks of local anesthetic systemic toxicity (LAST). Vital parameters (continuous electrocardiogram, pulse rate, oxygen saturation, respiratory rate, and blood pressure) are monitored and continued for 30 min after the procedure. The skin is prepped and draped, and face masks, caps, sterile gloves, and a sterile probe cover are donned. Sterile ultrasound trans- mission gel and a Stimuplex® Ultra 22G 0.64 × 50 mm, 30°, short bevel (B. Braun, Melsungen, Germany) non-traumatic needle are used. The LA consists of ropivacaine 0.375%, in (four) la- beled 10 ml syringes, to allow for a high-volume block without exceeding the maximum dos- age. Alternatively, ropivacaine 0.75%, which is also used by anesthesiologists for providing surgical pain relief, can be used. The maximum allowed dose of LA is 2 mg kg–1 body weight of ropivacaine, injected in 1–2 ml increments under direct ultrasound guidance to confirm the optimal spread of LA around the femoral nerve or below the iliac fascia (FICB). Negative aspiration is confirmed at least every 5 ml to prevent intravascular injection.
In addition to the EPs and EPs in training, all ED nurses were trained to be familiar with the SOP and to be able to assist in the procedures.
The procedure was recorded in the electronic medical record (EMR) according to the SOP. Relevant and additional data were recorded on a dedicated case report form, including gen- der, age, fracture type and location, and prehospitally administered analgesics (type, dosage, and route of administration). The indication and type of the nerve block, LA dosage, scores on physician and patient satisfaction, pain scores, any rescue medication, adverse events, and any reason to abandon the procedure were also recorded. Vital signs were recorded only in the EMR.
Pain scores were taken in rest on a numeric rating scale (NRS; 0–10) on arrival at the ED (t0) and after the procedure at 30, 60, and 120 min (t30, t60, and t120, respectively), but only if still in the ED. We considered a nerve block to be successful whenever there was a pain reduc- tion of at least two points after 30 min compared to baseline. We considered a pain reduction of at least 33% to be clinically important, as inspired by the work of Farrar.18 An absolute pain score of 4 or less, though, was considered acceptable pain.