Is the mortality frequency of the neuraxial anesthesia lower than mortality frequency of the general anesthesia for orthopedic surgeries?

MEDLINE (Medical Analysis and Retrieval System Online) via PubMed (1966 to 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 9, 2012), Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) available at http://regional.bvsalud.org/php/index.php from 1982 to 2012, and SCIELO (Scientific Electronic Library Online) available at http://www.scielo.br, the reference lists of included studies, and the reference list of the systematic reviews in this area published before this research. There will not be restrictions for any language, date, and document format.

Search strategy for MEDLINE via PubMed will be: ((“Anesthesia, General”[MESH]) OR (Anesthesias, General) OR (General Anesthesia) OR (General Anesthesias) OR (Anesthesia, Inhalation) OR (Inhalation Anesthesia) OR (Insufflation Anesthesia) OR (Anesthesia, Insufflation) OR (Anesthesia, Intravenous) OR (Anesthesias, Intravenous) OR (Intravenous Anesthesia) OR (Intravenous Anesthesias)) AND ((neuraxial anesthesia) OR (“Anesthesia, Conduction”[MESH]) OR (Conduction Anesthesia) OR (Anesthesia, Regional) OR (Regional Anesthesia) OR (“Anesthesia, Epidural”[MESH]) OR (Anesthesia, Peridural) OR (Peridural Anesthesia) OR (Anesthesia, Extradural) OR (Extradural Anesthesia) OR (Epidural Anesthesia) OR ("anesthesia, spinal"[MeSH]) OR (Anesthesias, Spinal) OR (Spinal Anesthesia) OR (Spinal Anesthesias)) AND ((“Orthopedics”[MESH]) OR (Orthopedic) OR (Orthopedic Surgery) OR (Orthopedic Surgeries) OR (Surgeries, Orthopedic) OR (Surgery, Orthopedic)).

Inclusion criteria: randomized controlled trials.

Exclusion criteria: quasi randomized controlled trials, and observational studies.

Patients with orthopedical injuries that require surgeries to improve quality in their health.

Inclusion criteria: participants aged 18 years or older with orthopedic disorders, and treated surgically.

Exclusion criteria: participants for orthopedic surgery performed together with other type of surgery.

The intervention group will be participants for neuraxial anesthesia (spinal anesthesia, epidural anesthesia or both).

The control group will be participants for general anesthesia.

Orthopedic surgery can be conducted under various anesthetic techniques but the most important is improving outcomes and reducing mortality. There is no agreement about which is the best anesthetic technique for surgeries in the inferior half of the body. Hence, in this systematic review we will assess randomised controlled trials evidence about the link between the choice of anesthetic technique and mortality frequency for othopedic surgeries.

Primary outcomes

The primary outcome will be mortality.

Secondary outcomes

The secondary outcomes will be: stroke, myocardial infarction, length of hospitalization, quality of life, satisfaction degree, postoperative cognitive dysfunction, and blood transfusion requirements.

Titles, abstracts, or both identified by the search strategy for PubMed and other databases will be independently reviewed by two investigators (Barbosa FT and Castro AA). Afterwards, RCTs identified as answering our research question will be requested for reading in full text. Data from RCTs will be recorded on a standardized form developed by the authors. Disagreements will be resolved by consensus meeting.

Data that will be extracted are: date of publication, types of participants, types of studies, types of surgeries, types of intervantions, method of randomization, allocation concealment, participants baseline characteristics, eligibility criteria, blinding, points estimates of the outcomes, statistical analysis, folow-up time, withdrawals and dropouts.

The study validity of the randomized controlled trials will be determined using several scales: the Jadad score, the Risk of Bias Table (Rob table), and the Delphi List.

The Jadad score is based on three topics: first, one point was given when the randomization was cited, an additional point was added if the randomization method was described and appropriate, and one point was deducted if this step was described incorrectly; second, one point was given when the study was double-blind, an additional point was added if this method was described and appropriate, and one point was deducted if this step was described incorrectly and third, one point was given when the numbers and reasons for withdrawals and dropouts were reported. Trials scoring three or more points were considered to having good validity.

The Rob table is based on topics: sequence generation, allocation sequence concealment, blinding, incomplete outcome data, selective outcome reporting and other sources of bias. Each item was judged subjectively looking for bias. Three possibilities of answers were possible: low risk of bias, high risk of bias, or unclear risk of bias.

The Delphi List has several questions: '1. Was a method of randomization performed?', '2. Was the treatment allocation concealed?', '3. Were the groups similar at baseline regarding the most important prognostic indicators?', '4. Were the eligibility criteria specified?', '5. Was the outcome assessor blinded?', '6. Was the care provider blinded?', '7. Was the patient blinded?', '8. Were point estimates and measures of variability presented for the primary outcome measures?', '9. Did the analysis include an intention-to-treat analysis?'. The answers could be yes, no, and do not know. Disagreements between the authors will be resolved by consensus meeting.

A priori studies identified as having poor methodological validity will not be excluded, but after pooling the results we will explore heterogeneity and withdraw studies that can mislead the result.

Meta-analyses will be performed using the Review Manager statistics: for dichotomous outcomes calculating relative risk and the number needed to treat with 95% confidence interval (95% CI) using random-effect model (REM); and for continuous outcomes calculating weighted mean difference with 95% CI using REM. Statistical heterogeneity would be assessed by using tests of heterogeneity: standard chi-squared test, and by the I-squared test where I-squared > 50% implies significant heterogeneity. The concordance between the authors was analyzed with the Kappa statistic coefficient.

None planned.

We will submit the review to a peer reviewed international journal and results will be presented at national and international conferences.

Fabiano Timb Barbosa

Comendador Palmeira Street, number 113 Farol, Maceió/AL. Brazil ZIP CODE 57051150

fabianotimbo@yahoo.com.br

None

Mr Fabiano Timbó Barbosa,
Mr Aldemar Araujo Castro,

01 August 2012

15 January 2013

None.

None known

Portuguese-Brazil

Brazil

Subject indexing assigned by CRD

Anesthesia; Humans; Mortality; Orthopedic Procedures

19 July 2012

13 February 2013