Nerve blocks for initial pain management of thigh bone fractures in children

Fractures (breaks) of the thigh bone can be very painful, particularly when a child arrives in a stressful emergency environment and is undergoing assessment. Moving the child to get X-rays or transferring the child to a special bed to support the leg in traction (keeping the leg straight) can cause additional pain, as can placing traction (a pulling force) on the broken thigh. This means that prompt provision of pain relief is an essential part of initial emergency management. This review investigated whether a nerve block, involving the injection of a freezing/numbing medication at the top of the thigh, would provide more effective pain relief than pain medicine given by mouth or into a vein (intravenously, e.g. morphine).

We searched several medical databases and trial registries up to January 2013 and contacted researchers. We found one study that looked at the comparison we were interested in. This study was potentially biased, mainly because the care providers, parents and children were aware of the type of pain relief the children received. The study was small, involving 55 children aged 16 months to 15 years, and showed that the children who received one of the two main types of nerve block tended to have less pain after 30 minutes than those who received intravenous morphine for initial pain control. The nerve blocks led to some pain and redness at the injection site in a few cases, while intravenous morphine caused more serious problems such as depressed breathing (lack of oxygen), excessive sleepiness and vomiting in a small number of children.

Moreover, children who had nerve blocks continued to have lower pain scores over a six-hour period with less need for additional pain relief. There was insufficient evidence to determine whether children or parents were more satisfied with one method of pain relief than the other. Use of resources (e.g. nursing time, cost of medications) was not measured.

The quality of the study included in this review was low and so these conclusions are not certain. Further well designed studies investigating whether nerve blocks are more effective and safer than other means of pain relief are needed.

Authors' conclusions: 

Low quality evidence from one small trial suggests that FICB provides better and longer lasting pain relief with fewer adverse events than intravenous opioids for femur fractures in children. Well conducted and reported randomised trials that compare nerve blocks (both FNB and FICB) with systemic analgesia and that use validated pain scores are needed.

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Background: 

Children and adolescents with femoral fractures are almost always admitted to hospital. They invariably start their hospital experience in the Emergency Department, often requiring transfer to a specialist children's hospital. They require analgesia or anaesthesia so that radiographs can be obtained and for management of their fractures. The initial care process involves from two to six transfers from stretcher to stretcher/imaging/operating-suite table or hospital bed within the first few hours, so prompt pain relief is essential. Systemic analgesia can be provided orally or parenterally. Alternatively, a nerve block may be used where local anaesthetic is injected around a nerve to block sensation or freeze the involved area.

Objectives: 

To assess the effects (benefits and harms) of femoral nerve block (FNB) or fascia iliaca compartment block (FICB) for initial pain management of children with fractures of the femur (thigh bone) in the pre-hospital or in-hospital emergency setting, with or without systemic analgesia.

Search strategy: 

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (11 January 2013), the Cochrane Central Register of Controlled Trials (2012 Issue 12), MEDLINE (1946 to January Week 1 2013), EMBASE (1980 to 2013 Week 01), Google Scholar (31 January 2013) and trial registries (31 January 2013). We handsearched recent issues of specialist journals and references of relevant articles.

Selection criteria: 

Randomised and quasi-randomised controlled trials assessing the effects of FNB or FICB for initial pain management compared with systemic opiates in children (aged under 18 years) with fractures of the femur receiving pre-hospital or in hospital emergency care. Primary outcomes included failure of analgesia at 30 minutes, pain levels during procedures and transfers (e.g. to a stretcher or hospital ward) for up to eight hours, and adverse effects.

Data collection and analysis: 

Two review authors independently extracted data using a pre-piloted form. Two authors independently assessed the risk of bias for the included study and assessed quality of the evidence for each outcome using the GRADE approach; i.e. as very low, low, moderate or high. Meta-analysis of results was not possible as we found only one trial that could be included in the review.

Main results: 

We included one randomised trial of 55 children aged between 16 months to 15 years. It compared anatomically-guided FICB versus systemic analgesia with intravenous morphine sulphate. The small sample size and the high risk of bias relating to lack of blinding resulted in a low quality rating for all outcomes.

Overall, the trial provided low quality evidence for better pain management in the FICB group. Fewer children in the FICB group had analgesia failure at 30 minutes than in the morphine group (2/26 (8%) versus 8/28 (29%); risk ratio (RR) 0.33, 95% confidence interval (CI) 0.09 to 1.20; P value 0.09). The trial did not report on pain during procedures or transfers, or application of analgesia. The trial provided low quality evidence that FICB has a better safety profile than morphine, with only four (15%) reports of redness and pain at the injection site, and no reports of the type of adverse effects of systematic analgesia that occurred in the morphine group, such as respiratory depression (six cases (21%)) and vomiting (four cases (14%)). No long-term adverse events were reported for either intervention. Clinically significant pain relief was achieved in both groups at five minutes; with limited evidence of greater initial pain relief in the FICB group. Based on an inspection of graphically-presented data, at least 46% (12/26) of children in the FICB group had no supplementary medication (mainly analgesia) for the six hours of the study, while only 5% (1 or 2/28) of children in the intravenous morphine group went without additional analgesia. There was insufficient evidence to determine whether child or parental satisfaction with the method of analgesia favoured either method. Resource use was not measured.

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