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National Clinical Guideline Centre (UK). The Management of Hip Fracture in Adults [Internet]. London: Royal College of Physicians (UK); 2011. (NICE Clinical Guidelines, No. 124.)

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The Management of Hip Fracture in Adults [Internet].

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8Regional (spinal or epidural) versus general anaesthesia

8.1. Introduction

Patients who have a proximal femoral fracture are usually offered surgery to treat the injury. The vast majority of these operations will require some type of anaesthesia. Anaesthesia may be general anaesthesia or regional anaesthesia.

General anaesthesia involves complete loss of consciousness. This may be achieved by either inhalational agents or intravenous anaesthetic agents. Regional anaesthesia is conducted by numbing the nerves that supply sensation to the lower limbs, with the injection of local anaesthetic solution into the fluid surrounding the spinal cord. There are two types of regional anaesthesia, spinal and epidural. During a spinal, local anaesthetic drugs, sometimes in combination with opioid painkillers are injected directly into the cerebro-spinal fluid of the spinal cord. The majority regional anaesthesia administered to hip fracture patients is spinal anaesthesia rather than epidural.

Hip fracture patients are generally elderly and have significant comorbidities. This increases the risks from all types of anaesthesia. At present both regional and general anaesthesia are administered but the eventual choice is the preference and experience of the anaesthetist in discussion with the patient and their carers.

The aim of this review is to identify whether regional anaesthesia confers any benefit compared to general anaesthesia with regards to reducing complications and improving patient outcomes after surgery.

8.2. Regional versus general anaesthesia

8.2.1. Review question

In patients undergoing surgical repair or replacement for hip fractures, what is the clinical and cost-effectiveness of regional (spinal/epidural) anaesthesia compared to general anaesthesia in reducing complications such as mortality, cognitive dysfunction, thromboembolic events, postoperative respiratory morbidity, renal failure and length of stay in hospital?

8.2.1.1. Clinical evidence

The literature search retrieved one Cochrane review (Parker et al 2004)266 including 22 RCTs with a total of 2567 participants. A further update search was then conducted to search for any papers that may have been published since the publication of this review. No additional studies were retrieved and therefore the clinical evidence presented in this chapter is based on the Parker et al results with the addition of the GRADE analysis.

In addition, we conducted a systematic review on patient views to look for evidence on patient preference as this was one of the main outcomes.

See evidence table 4, Appendix E, forest plots G38 to G49.

Table 8-26General vs. regional anaesthesia – Clinical study characteristics

OutcomeNumber of studiesDesignLimitationsInconsistencyIndirectnessOther considerations/imprecision
Mortality (early up to 1 month)1,20,23,65,66,167,210,211,277,334,33911RCTSerious limitations (a), (b)No serious inconsistencyNo serious indirectnessSerious Imprecision (c)
Mortality at 1 month20,65,66,167,210,211,277,3398RCTSerious limitations (a), (b)No serious inconsistency (d)No serious indirectnessSerious Imprecision (c)
Length of stay in hospital210,2772RCTSerious limitations (a), (b)No serious inconsistencyNo serious indirectnessSerious imprecision
Vomiting23,2112RCTSerious limitations (a), (b)No serious inconsistencyNo serious indirectnessSerious Imprecision (c)
Acute confusional state20,23,46,169,2775RCTSerious limitations (a), (b)No serious inconsistencyNo serious indirectnessSerious imprecision (c)
Pneumonia1,20,23,65,66,167,210,211,2779RCTSerious limitations (a), (b)No serious inconsistencyNo serious indirectnessSerious Imprecision (c)
Myocardial infarction65,66,167,210,211,2776RCTSerious limitations (a), (b)No serious inconsistencyNo serious indirectnessSerious Imprecision (c)
Pulmonary embolism1,20,23,36,65,66,210,211,2779RCTSerious limitations (a), (b)No serious inconsistency (e)No serious indirectnessSerious Imprecision (c)
Deep vein thrombosis36,65,210,2114RCTSerious limitations (a), (b)No serious inconsistencyNo serious indirectnessSerious Imprecision (c)
a

Some of the studies did not report definite allocation concealment

b

None of the trials clearly stated whether it was an intention to treat analysis

c

The relatively few events and few patients give wide confidence intervals around the estimate of effect. This makes it difficult to know the true effect size for this outcome.

d

Pooling of the results showed some but not statistically significant heterogeneity: I2 = 31% (p= 0.18)

e

The results of pooling all pulmonary embolism events showed statistical heterogeneity I2 = 47% (p= 0.06). The authors suggest this is mainly due to the significantly different in trials presenting results for fatal and non fatal pulmonary embolism. These were subsequently analysed in separate meta-analyses.

Table 8-27General vs. regional anaesthesia - Clinical summary of findings

OutcomeInterventionControlRelative risk (95% CI)Absolute effectQuality
Mortality (early up to 1 month)64/912 (7%)93/966 (9.6%)RR 0.73 (0.54-0.99)26 fewer per 1000 (from 1 fewer to 44 fewer)Low
Mortality at 1 month56/811 (6.9%)86/857 (10%)RR 0.69 (0.50, 0.95)31 fewer per 1000 (from 5 fewer to 50 fewer)Low
Length of stay in hospital108110N/AMean Difference 0.21 (-5.21-4.78)Low
Vomiting2/46 (4.3%)3/49 (6.1%)RR 0.7 (0.12-3.94)18 fewer per 1000 (from 54 fewer to 179 more)Low
Acute confusional state11/117 (9.4%)23/120 (19.2%)RR 0.5 (0.26-0.95)96 fewer per 1000 (from 10 fewer to 142 fewer)Low
Pneumonia21/574 (3.7%)29/612 (4.7%)RR 0.76 (0.44-1.3)11 fewer per 1000 (from 26 fewer to 14 more)Low
Myocardial infarction5/502 (1%)11/531 (2.1%)RR 0.55 (0.22-1.37)9 fewer per 1000 (from 16 fewer to 8 more)Low
Pulmonary embolism9/605 (1.5%)13/640 (2%)RR 0.88 (0.32-2.39)2 fewer per 1000 (from 14 fewer to 28 more)Low
Deep vein thrombosis39/129 (30.2%)61/130 (36.9%)RR 0.64 (0.48-0.86)169 fewer per 1000 (from 66 fewer to 244 fewer)Low

8.2.1.2. Economic evidence

One study was identified. Chakladar 201048 is a cost study of general vs. spinal anaesthesia based on a survey. Please see Economic Evidence Table 13 in Appendix F for further details.

Table 8-28General anaesthesia vs regional anaesthesia- Economic study characteristics

StudyLimitationsApplicabilityOther Comments
Chakladar 201048Potentially serious limitations (a)Partially applicable (b)Cost analysis of general anaesthesia vs. spinal anaesthesia.
a

Not a full economic evaluation – costs but not health effects. Cost analysis based on responses to a questionnaire, not on a direct audit of equipment usage. Overhead costs and cost of treating side effects were not included. No sensitivity analysis.

b

UK study but does not estimate QALYs.

Table 8-29General anaesthesia vs regional anaesthesia - Economic summary of findings

StudyIncremental cost (£)Incremental effectsICERUncertainty
Chakladar 20104876.77(a)NANANR
a

General anaesthesia more costly than regional anaesthesia (SD):£270.58 (44.68) vs 193.81 (44.68); p<0.0001

8.2.1.3. Evidence statement (s)

ClinicalThere is a statistically and clinically significant reduction in early mortality (up to 1 month) in patients having regional anaesthesia compared to those having general anaesthesia (LOW QUALITY).

There is a statistically significant but not clinically significant improvement in postoperative confusion and reduction in incidence of deep vein thrombosis in patients receiving regional compared to general anaesthesia (LOW QUALITY).

There were no statistically significant differences in length of stay in hospital, vomiting, pneumonia, myocardial infarction and pulmonary embolism (LOW QUALITY).
EconomicOne study found general anaesthesia to be more costly than spinal anaesthesia. This evidence has very serious limitations since it did not evaluate effectiveness and may not have included all important cost differences.

8.2.2. Recommendations and link to evidence

RecommendationOffer patients a choice of spinal or general anaesthesia after discussing the risks and benefits.
Relative values of different outcomesThe GDG considered early mortality (up to 1 month) and patient preference to be the most important outcomes.
Trade off between clinical benefits and harmsMost clinical benefit was seen in patients undergoing regional anaesthesia. However, there is a small chance of nerve damage following regional anaesthesia.

Potential benefits with regional also include, reduction in venous thromboembolic (VTE) complications but studies were conducted in patients not receiving VTE prophylaxis which may lead to some false positive results. However, this finding is supported by a more comprehensive review of DVT and PE across all surgical patients in the NICE guideline on venous thromboembolism prophylaxis225.

A potential benefit of general anaesthesia includes lack of awareness throughout the surgical procedure. Indeed some patients perceive unconsciousness during general anaesthesia as a benefit. However, others fear the loss of control. A potential disadvantage of general anaesthesia is that recovery on the first postoperative day may be slower.
Economic considerationsThe GDG felt that because of the potentially serious limitations of the study included as economic evidence there were insufficient data to claim that the overall costs of the general and regional anaesthesia are substantially different.

However, there was agreement in acknowledging that spinal anaesthesia usually involves lower costs for drugs, anaesthesia equipment and airway equipment than general anaesthesia.

Nevertheless, these lower costs of regional anaesthesia could be offset by its longer administration time. The GDG debated at length whether regional anaesthesia required more time to be administered compared to general anaesthesia, but no agreement was reached.
Quality of evidenceThe studies comparing the two types of anaesthesia were mainly of low methodological quality. They included small numbers of participants and only reported a few outcome measures. These varied between studies making pooling of the data difficult. The studies lacked methodological rigour in particular regarding allocation concealment, assessor blinding and intention to treat analysis. The studies are now considered to be out of date and no longer relevant to current anaesthesia and perioperative care. In addition, they do not account for the advances in safety in the field of anaesthesia. For example in some of the studies patients allocated to general anaesthesia did not receive thrombo-prophylaxis as part of routine care.

The economic evidence has very serious limitations, as it is based on responses to a questionnaire on a hypothetical anaesthetic technique, and not a direct audit of actual equipment usage. Moreover, the analysis did not look at whether there are any potential savings linked to a reduction in the cases of confusion when regional anaesthesia is used.
Other considerationsThe GDG also considered the evidence for other outcomes such as length of stay in hospital and adverse events including vomiting, acute confusional state and respiratory and cardiac complications. In the absence of any strong evidence favouring one method over the other, the GDG decided that the choice of anaesthesia should be based on the patient preference after being given sufficient information about the options available and the expertise of the anaesthetist.
RecommendationConsider intraoperative nerve blocks for all patients undergoing surgery.
Relative values of different outcomesThe GDG considered pain relief, postoperative mobility and reduction in opioid usage to be the main outcomes.
Trade off between clinical benefits and harmsAs discussed in chapter 7 on using nerve blocks for hip fracture analgesia, local nerve blocks may serve as a means of reducing the need for, and side effects of, opioids and other analgesia. However, they are associated with a very rare incidence of nerve damage and must be admisitered by trained health care professionals.
Economic considerationsThe GDG agreed this likely to be cost-effective because the administration of nerve blocks avoids the complications and side effects of opioids, and therefore might result in a reduced length of hospital stay. Please see the analgesia chapter for evidence on the cost-effectiveness of nerve blocks in general.
Quality of evidenceThe evidence that nerve blocks reduce the degree of pain and the requirement for opioid analgesics compared to other forms of analgesia alone, and that they may have fewer side effects compared to systemic analgesia, is presented under Analgesia (Chapter 7). This includes several studies studies that have investigated the effectiveness of nerve blocks in conjunction with general anaesthesia to determine if this reduces the requirements for opioid analgesics and improve pain management. These studies show that nerve blocks reduce the degree of pain compared to systemic analgesia alone and that they may have fewer side effects compared to systemic analgesia. However, these studies could not be subgrouped in a meaningful way as they looked at different outcomes and differed in the way they reported them. Therefore, this recommendation was partly based on consensus.
Other considerationsNerve blocks are often administered before a spinal anaesthetic, in order to position the patient. They are usually administered before a general anaesthetic and many are now conducted using ultrasound guidance. This reduces the chance of complications, such as an intraneural injection and also enables the dose of local anaesthetic administered to be lower. The use of nerve blocks in surgery has increased in recent years and has almost become routine practice. Therefore, studies to show any benefit may now be difficult to conduct, as withholding analgesia from such patients may be unethical. Administration of nerve blocks should not delay surgery.

8.3. Research recommendation on anaesthesia

The GDG recommended the following research question:

What is the clinical and cost effectiveness of regional versus general anaesthesia on postoperative morbidity in patients with hip fracture?

Why this is important

No recent randomised controlled trials were identified that fully address this question. The evidence is old and does not reflect current practice. In addition, in most of the studies the patients are sedated before regional anaesthesia is administered and this is not taken into account when analysing the results. The study design for the proposed research would be best addressed by a randomised controlled trial. This would ideally be a multi-centred trial including 3,000 participants in each arm. This is achievable if one considers that there are 70, 000 hip fractures a year in the UK39. The study should have three arms which look at spinal anaesthesia versus spinal anaesthesia plus sedation versus general anaesthesia, this would separate those with regional anaesthesia from those with regional anaesthesia plus sedation. The study would also need to control for surgery, especially type of fracture, prosthesis and grade of surgeon.

A qualitative research component would also be helpful to study patient preference for type of anaesthesia.

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Copyright © 2011, National Clinical Guideline Centre.

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Bookshelf ID: NBK83023

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