To determine whether the use of regional anaesthesia affects surgical time when compared to general anaesthesia.

MEDLINE was searched from 1966 to May 1997. Details of the search strategy are given. Published manuscripts were also sought from sources including textbooks and experts in the field.

Study designs of evaluations included in the review

Randomised controlled trials (RCTs) meeting the following criteria were included: data was given for specific operations; and means and standard deviations of surgical time were reported. Articles not specifically reporting surgical time were excluded. For studies considered to be duplicates, results from the manuscript with the largest number of patients in each group were selected for inclusion.

Specific interventions included in the review

General anaesthesia and regional anaesthesia including epidural, local, retro bulbar, peribulbar, and spinal were studied.

Participants included in the review

Patients undergoing the following types of surgical procedures were included: Caesarean delivery; prostatectomy including transvesical, retro pubic and transurethral; total hip replacement; total knee replacement; laparoscopic tubal ligation; tonsillectomy; cataract; fractured femur; fractured hip; lumbar laminectomy; and knee arthroscopy.

Outcomes assessed in the review

Surgical time was assessed.

How were decisions on the relevance of primary studies made?

The author does not state how the papers were selected for the review, or how many of the reviewers performed the selection.

The author does not state that they assessed validity.

The author does not state how the data were extracted for the review, or how many of the reviewers performed the data extraction. Confidence intervals for differences between mean times were calculated for each study using students' t-test and pooled standard deviations.

How were the studies combined?

Pooled mean differences were calculated using a random-effects meta-analysis (unweighted variance method).

How were differences between studies investigated?

The effect of the type of regional anaesthesia on mean difference was assessed by repeating the analysis after excluding local anaesthesia and retro bulbar block and the effect of the type of surgery assessed by analysing separately data from patients undergoing total hip replacement.

Twenty-six RCTs were included (N = 1874 patients).

Regional anaesthesia was not found to significantly decrease surgical time. Summary mean difference (regional anaesthesia minus general): 1.7 minutes (95%CI: - 0.05, 3.9 minutes).

After exclusion of patients undergoing local or retro bulbar block: mean difference = 1.8 minutes: (95%CI: - 1.2, 4.9 minutes).

There was a trend for regional anaesthesia to decrease surgical time for studies of total hip replacement. Patients undergoing total hip replacement (5 studies, 3 epidural and 2 spinal): mean difference was statistically significant: 7.0 minutes (95%CI: 3.0, 11.1 minutes).

Overall, the use of regional analgesia does not significantly decrease surgical time.

The aims and inclusion criteria were stated. Some investigation of the influence of study characteristics on results was undertaken. Heterogeneity among studies was demonstrated graphically, though not assessed statistically. The following potential limitations of the review were considered: publication bias; and inaccurate measurement of surgical time.

By limiting the literature search to one database, albeit with consultation with experts, some relevant studies may have been omitted. It is not clear whether language restrictions were applied. No details were given of methods used to select primary studies or extract data and it appears that only one reviewer was involved. No definition of 'surgical time' was given. Validity was not assessed.

In view of the lack of validity assessment and lack of definition of the outcome 'surgical time', the author's conclusions cannot be considered supported by the evidence presented.

Practice: The author considers that the use of regional anaesthesia in unlikely to affect labour costs in operating rooms.

Research: The author does not mention any research implications of the review.

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.