A national survey of acute hospitals in England on their current practice in the use of femoral nerve blocks when splinting femoral fractures

Abstract

Introduction: Missed compartment syndrome can have devastating long-term impact on a patient's function. Femoral fracture has been reported in 52-58% of acute thigh compartment syndromes in the existing literature. Time to diagnosis of compartment syndrome is cited as a key determinant of outcome. Use of femoral nerve blocks in splinting of femoral fractures may mask signs of early compartment syndrome. We present the attitudes of emergency department and orthopaedic staff in NHS trusts in England with regard to this issue.

Methods and materials: Survey of all 171 acute hospitals in the United Kingdom accepting trauma admissions. On-call middle grade doctors in emergency and orthopaedic department completed a telephone survey into departmental protocol and their experience of femoral nerve blocks for lower limb fractures.

Results: Middle grades from all 171 trusts completed the survey (100% response rate). 54 emergency departments (30.8%) had a protocol for the use of femoral nerve blocks. Middle grades in the ED reported using a nerve block routinely in 95 hospitals (54%) with 63 using a long-acting and 32 a short-acting agent. Of those that did not 70% (n=53) felt they were unnecessary, 21% (n=16) were not confident in the technique and 9% (n=7) had worries over compartment syndrome. 68% would be worried about compartment syndrome in high-energy injuries. Orthopaedic departmental protocols for nerve block use were reported in 16 trusts (9%). 45 orthopaedic middle grades (26%) indicated that they would use them routinely with 17 using long-acting and 28 using short-acting agents. 59.5% (n=75) of orthopaedic middle grades felt nerve blocks were unnecessary, whilst 22% (n=28) had worries about compartment syndrome and 18% (n=23) were not confident with the technique. 77% orthopaedic middle grades would be more worried about compartment syndrome in high energy injuries.

Conclusion: Femoral nerve block is an under-utilised, effective mode of analgesia following femoral fractures. There is a low risk of associated compartment syndrome, but clinicians should be especially vigilant in high-energy injuries. We recommend that all acute trusts receiving trauma should have a protocol for the use of femoral nerve blocks agreed by the emergency and orthopaedic departments.