CRD summary

The authors concluded there was insufficient evidence on the effects of regional versus general anaesthesia for a range of outcomes in patients undergoing total hip arthroplasty, but regional anaesthesia may reduce blood loss, post-operative pain, morphine consumption, nausea and vomiting. Given inadequate reporting of the review methods and poor study quality, it is difficult to be confident of these findings.

Authors' objectives

To compare general anaesthesia versus regional anaesthesia and systemic versus regional analgesia in patients undergoing total hip arthroplasty.

Searching

MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from 1990 to October 2008, for studies published in English. Search terms were reported. In addition, reference lists of retrieved studies were handsearched.

Study selection

Randomised controlled trials (RCTs) were included if they compared general anaesthesia versus regional anaesthesia for surgery, or compared systemic versus regional analgesia, for postoperative analgesia in patients undergoing total hip arthroplasty. Eligible trials had to evaluate one of the following outcomes: mortality; cardiovascular morbidity; deep vein thrombosis and pulmonary embolism; blood loss; duration of surgery; pain; opioid-related adverse effects; cognitive defects; or length of hospital stay. Trials of hip or knee arthroplasty were included only if data on total hip arthroplasty were presented separately. Trials that evaluated opioid-only neuraxial methods were excluded.

The included trials evaluated general anaesthesia, various types of regional anaesthesia (including spinal anaesthesia, continuous spinal, epidural anaesthesia and lumbar plexus block) and combinations of general anaesthesia plus regional anaesthesia. Trials used a variety of different types of analgesia (including continuous forms of psoas block, lumbar plexus block, epidural analgesia, femoral nerve block and spinal analgesia) and systemic analgesia (including systemic opioids, intramuscular and intravenous opioids, intravenous opioid infusions, and acetaminophen). Where reported, the mean age of patients ranged from 52 to 74 years, the percentage of males ranged from 0 to 68% and the American Society of Anesthesiologists grade (for patient fitness before surgery) ranged from I (normal/healthy) to III (severe systemic disease).

Two reviewers conducted the searches but no other details of the study selection process were reported.

Assessment of study quality

Trial quality was assessed using the Jadad criteria (randomisation, blinding and withdrawals), allocation concealment and follow-up rates of less than 80%. Trials scoring 3 or more out of the maximum possible 5 points were considered to be of satisfactory quality. It was not clear how many reviewers performed this part of the validity assessment. Two reviewers independently graded each RCT as level I (high-quality) or level II (lesser-quality).

Data extraction

Data were extracted onto a templated form. For each trial, outcome data were presented in supplementary tables as numbers or percentages for dichotomous outcomes and means with p values for continuous outcomes.

The authors did not state how many reviewers performed the data extraction.

Methods of synthesis

The studies were combined in a narrative synthesis. Differences between trials were apparent from tables and the text.

Results of the review

Eighteen RCTs were included (n=1,239 patients). Only two RCTs were graded level I. Ten RCTs scored 2 or less out of 5 points on the Jadad score. In 13 RCTs, allocation concealment was unclear. Follow-up was adequate in all trials. The follow-up period for mortality ranged from 48 hours to 16 days.

There was insufficient evidence of the effects of general anaesthesia versus regional anaesthesia on the following: mortality (two RCTs reported no difference); cardiovascular morbidity (six RCTs reported effects of different interventions on different outcomes); or deep vein thrombosis and pulmonary embolism when thromboprophylaxis was used (two RCTs reported no difference in proximal deep vein thrombosis).

Four of 10 RCTs reported reduced blood loss in regional anaesthesia compared to general anaesthesia groups; the other six RCTs reported no significant difference.

There was no difference between general anaesthesia and regional anaesthesia for duration of surgery (12 RCTs).

Compared to systemic analgesia, regional analgesia was associated with a reduction in post-operative pain or morphine consumption (in 10 out of 11 RCTs) and nausea and vomiting (four of nine RCTs, the other five reported no significant difference).

There was no difference between regional anaesthesia, regional analgesia or both versus general anaesthesia plus systemic analgesia for length of stay in hospital (four RCTs) or rehabilitation outcomes (three RCTs).

Some results were reported in supplementary online tables (see URL for Additional Data).

Authors' conclusions

There was insufficient evidence to determine if the method of anaesthesia influenced mortality, cardiovascular morbidity, or deep vein thrombosis and pulmonary embolism when combined with thromboprophylaxis, in patients undergoing total hip arthroplasty. Regional analgesia may reduce blood loss compared with general anaesthesia, as well as post-operative pain, morphine consumption, nausea and vomiting compared with systemic analgesia. There was no improvement in length of stay or rehabilitation associated with regional anaesthesia or analgesia.

CRD commentary

The review question was clearly stated and inclusion criteria were appropriately defined. Several relevant sources were searched, but no attempts were made to minimise publication or language bias. The potential for language bias was acknowledged by the authors. Methods were used to minimise reviewer errors and bias in the grading of study validity, but it was not clear whether similar steps were taken in study selection or data extraction.

Only RCTs were included; their validity was assessed and results were reported, and the limitations of the quality of the trials were discussed. In view of the differences between trials, a narrative synthesis was appropriate.

Evidence appeared to support the authors’ conclusions. However, although much of the review was clearly reported, inadequate reporting of review methods and generally poor quality of the small included studies make it difficult to be confident of the reliability of the conclusions.

Implications of the review for practice and research

Practice: The authors did not state any implications for practice.

Research: The authors stated that larger higher-quality RCTs are required to evaluate the effects of regional anaesthesia on patients undergoing total hip arthroplasty, including effects on deep vein thrombosis in the presence of thrombolysis and cardiovascular morbidity.

Funding

Not stated.

Bibliographic details

Macfarlane AJ, Prasad GA, Chan VW, Brull R. Does regional anaesthesia improve outcome after total hip arthroplasty: a systematic review. British Journal of Anaesthesia 2009; 103(3): 335-345. [PubMed: 19628483]

Original Paper URL

http://bja.oxfordjournals.org/content/103/3/335.abstract

Indexing Status

Subject indexing assigned by NLM

MeSH

Aged; Aged, 80 and over; Analgesia /methods; Anesthesia, Conduction /adverse effects; Arthroplasty, Replacement, Hip /adverse effects /rehabilitation; Cardiovascular Diseases /etiology; Female; Humans; Length of Stay; Male; Middle Aged; Pain, Postoperative /prevention & control; Randomized Controlled Trials as Topic; Treatment Outcome

AccessionNumber

12009107883

Database entry date

21/04/2010

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.