Jeff Holoman, D.O. | EM/FM PGY 3
The Article:
The Idea:
To compare the efficacy of US guided three-in-one femoral nerve blocks to standard treatment with IV morphine for pain control in elderly patients with hip fractures in the Emergency Department.
The Study:
A blinded, randomized control clinical trial at Rhode Island Hospital which included all patients over the age of 55 with radiographic findings of a femoral neck fracture or intertrochanteric fracture. Identified patients were also neurovascular intact, in moderate to severe pain (numerical pain rating scale > 5), and were able to consent to the study. After consent, the patients were randomized using sequentially numbered cards in sealed envelopes to one of two groups: femoral nerve block plus morphine (FNB) or standard care, morphine alone + sham injection (SC). Each participant in the FNB group received an US-guided femoral nerve block performed by physicians who had prior experience performing the technique and underwent a 30-minute training session to standardize the approach. FNB procedures were standardized according to patient positioning, injections of 25mL of bupivacaine, as well as holding manual pressure post injection for 5 minutes, 1 cm below the injection site. Each patient in the SC group received a sham injection that was intended to blind the participant and the treating physician. Set up and procedure of the SC group was also standardized to entail a 3mL 0.9% injection of saline, given subcutaneously over 5 minutes. Following administration of the FNB or sham injection, it was then left to the physician caring for the patient to choose analgesia dosing and frequency for the remainder of their ED stay. To assess the primary goal of pain relief, a patient reported pain scoring system was used. The summed pain-intensity difference (SPID) was used over a 4 hour study period. Trained professionals then asked participants to report their pain using an 11 point numerical rating scale (NRS), 0 being “no pain,” up to 10 being “worst pain imaginable.” Repeat measurements were then taken at the 15 minute, 1, 2 and 4 hour periods after the study procedure was performed. A pain – intensity difference (PID) was calculated at each time point. The PID was calculated as the change from baseline NRS for each measurement in time for the two groups. Secondly, review of the dose and amount of opioids used were measured to assess if those in the FNB group received less opioids. This secondary efficient variable was the total amount of opioid received after the study procedure, while the patient was in the Emergency Department. Rescue analgesia and SPID measurements for each group were also tested and compared.
The Findings:
Sixty-four patients were screened for the study with 38 being enrolled, with two patients from each arm dropping out after randomization. Eighteen patients in each arm completed the study. There was no significant difference between treatment groups with respect to age, sex, fracture type and vital signs or length of stay in the ED. There was also no significant difference between pre-enrollment analgesia or baseline pain intensity. Of note, there was a significant decrease in pain intensity in the patients in the FNB group over time ( p < 0.01 ), whereas those in the SC did not have any change in pain reduction over time ( p = 0.882 ). The SPID over 4 hours was significant greater in the FNB group ( 11.0 vs. 4.0). In addition, a significantly higher proportion of individuals in the FNB group achieved as least 33% reduction in pain intensity over time, 33% SPID, (12 vs. 0). 1/3 of the patients in the SC group had a negative %SPID, indicating that they had increasing pain throughout the study period. Regarding the second measure of the study, opioid use, patients in the FNB group received far less than the SC group (0.0 to 6.0 mg vs. 0.0 to 21.0 mg). Five patients in the FNB group received rescue analgesia versus 14 patients in the SC group. There was no significant association between dose of rescue analgesia and %SPID in the FNB group (r=-.-7, r^2=0.005) and only a weak association in the SC group (r=0.20 , r^2=0.04). There were no differences in the adverse effects of hypotension, hypoxia, or nausea/vomiting.
The Takeaway:
Usage of bedside US guided femoral three-in-one nerve blocks seemingly provides superior pain relief in comparison to parenteral opioids alone and requires less rescue analgesia while in the Emergency Department.