[Acute pain management in proximal femoral fractures: femoral nerve block (catheter technique) vs. systemic pain therapy using a clinic internal organisation model].

BACKGROUND: The aim of this study was to compare safety and efficacy of catheter-mediated femoral nerve block analgesia with systemic pain therapy in patients with proximal femoral fractures in the pre-operative and post-operative setting using a protocol for coordinating pain management.

METHODS: In a prospective randomised trial of patients attending the emergency department, 100 individuals were selected with a clinically diagnosed proximal femoral fracture. Patients were divided into two equal groups A and B. Group A (n=50) received a catheter-mediated femoral nerve block with 1% prilocaine (40 ml) and post-operatively 0.2% ropivacaine (30 ml) 6 hourly. Group B (n=50) initially received intravenous metamizol (1 g) and a fixed combination of oral tilidine (100 mg) + naloxone (8 mg). Patients aged 90 years or more received a reduced dose (tilidine 75 mg + naloxone 6 mg). In the post-operative period regular oral ibuprofen (400 mg, 8 hourly) in addition to oral tilidine (50 mg) + naloxone (4 mg) was given as required for break through pain. Pain intensity was measured using a verbal rating scale (VRS) from 1 to 5: pain free (=1), mild pain (=2), moderate pain (=3), severe pain (=4), excruciating pain (=5). Pain scores were recorded at rest (R), during passive anteflection (30 degrees) of the hip (PA) on arrival and at 15 and 30 min after initial administration of analgesia. Thereafter, recordings were made 4 times a day up to the third post-operative day.

RESULTS: Pain scores were comparable for both groups on admission (VRS in R 2.50 vs. 2.46; VRS during PA 4.30 vs. 4.34). Significant pain relief was achieved in both groups following initial administration of analgesia, but the total pain scores in group A were significantly lower than in group B (VRS in R 1.22 vs. 1.58, p<0.01 and VRS during PA 2.66 vs. 3.26; p<0.001). No difference was noted between the two groups during the first 3 post-operative days. No severe complications occurred as a result of analgesia, however, the catheter was dislodged in 20% of patients in group A resulting in the need for systemically administered analgesia.

CONCLUSION: All patients presenting with proximal femoral fractures should receive adequate analgesia within the emergency department even prior to radiographic imaging. Femoral nerve block should be considered as the method of choice. The insertion of a femoral nerve block catheter has the dual advantage of early analgesia permitting repeated clinical examination in addition to continued post-operative pain management. The cumbersome logistics inherent in this technique within the clinical setting limits its practical application. An initial single-shot regional nerve block followed by a systemic post-operative analgesia protocol was considered an appropriate alternative. The execution of safe, consistent and appropriate regional nerve block anaesthesia is reliant on formal guidelines and protocols as agreed by the multidisciplinary teams involved with patient-directed pain management and good clinical practice.