Enhanced recovery after vascular surgery: protocol for a systematic review

Background The enhanced recovery after surgery (ERAS) programme is a multimodal evidence-based approach to surgical care which begins in the preoperative setting and extends through to patient discharge in the postoperative period. The primary components of ERAS include the introduction of preoperative patient education; reduction in perioperative use of nasogastric tubes and drains; the use of multimodal analgesia; goal-directed fluid management; early removal of Foley catheter; early mobilization, and early oral nutrition. The ERAS approach has gradually evolved to become the standard of care in colorectal surgery and is presently being used in other specialty areas such as vascular surgery. Currently there is little evidence available for the implementation of ERAS in this field. We plan to conduct a systematic review of this literature with a view to incorporating ERAS principles into the management of major elective vascular surgery procedures. Methods We will search EMBASE (OVID, 1947 to June 2012), Medline (OVID, 1948 to June 2012), and Cochrane Central Register of Controlled Trials (Wiley, Issue 1, 2012). Searches will be performed with no year or language restrictions. For inclusion, studies must look at adult patients over 18 years. Major elective vascular surgery includes carotid, bypass, aneurysm and amputation procedures. Studies must have evaluated usual care against an ERAS intervention in the preoperative, perioperative or postoperative period of care. Primary outcome measures are length of stay, decreased complication rate, and patient satisfaction or expectations. Only randomized controlled trials will be included. Discussion Most ERAS approaches have been considered in the context of colorectal surgery. Given the increasing use of multiple yet different aspects of this pathway in vascular surgery, it is timely to systematically review the evidence for their independent or combined outcomes, with a view to implementing them in this clinical setting. Results from this review will have important implications for vascular surgeons, anaesthetists, nurses, and other health care professionals when making evidenced-based decisions about the use of ERAS in daily practice.


Background
The enhanced recovery after surgery (ERAS) programme is a multimodal evidence-based approach to surgical care which begins in the preoperative setting and extends through to patient discharge in the post operative period. This interprofessional, goal-directed pathway, involves surgeons, nurses, anaesthetists, and physiotherapists. It aims to accelerate the recovery of surgical patients while decreasing complications and reducing hospital length of stay. Since the early 1990s, the ERAS approach has gradually evolved to become the standard of care in colorectal surgery [1]. Advanced primarily by the Danish surgeon Dr. Henrik Kehlet [1][2][3][4][5][6][7][8][9], concepts in ERAS or fast-track surgery for colorectal patients have been studied and implemented internationally [10][11][12][13][14][15]. Evidence from randomized controlled trials suggests that ERAS protocols effectively and safely hasten the recovery of patients undergoing surgical colorectal procedures [14,[16][17][18]. The primary components of ERAS include the introduction of preoperative patient education; reduction in perioperative use of nasogastric tubes and drains; the use of multimodal analgesia; goal-directed fluid management; early removal of Foley catheter; early mobilization, and early oral nutrition.
The use of ERAS protocols is reported in other surgical specialty areas, such as vascular [19,20], cardiac [21] and orthopaedic surgery [22][23][24]. In vascular surgery, ERAS implementation is reported for aortic [19,20,[25][26][27][28] and carotid procedures [29]. Observational studies of elective vascular surgery patients (abdominal aortic aneurysm repair, aortobifemoral bypass grafting) using enhanced recovery pathways demonstrate reduced length of stay when compared with usual care [25,26,28]. A recent limited review of ERAS in open upper abdominal and thoracoabdominal surgery finds three studies evaluating ERAS in abdominal aortic surgery with positive outcomes for use of early oral nutrition and mobilization [30].
While there are a handful of general reviews on the topic of ERAS in vascular surgery [27,31,32] there is relatively little evidence for the use of an ERAS pathway in vascular surgery [33]. A systematic review of the literature is therefore timely with a view to incorporating ERAS principles into the management of major elective vascular surgery procedures. Our research question is: in adults over 18 years, what is the impact of enhanced recovery after surgery procedures in major elective vascular surgery in terms of reduced hospital length of stay, decreased complications, and improved patient expectations?

Methods/Design
Eligibility: We will include studies of adult patients over the age of 18 who have undergone major elective vascular surgery and received an ERAS intervention. For this review major elective vascular surgery is defined as a carotid, aneurysm, bypass, or amputation procedure (see Appendix I). Studies must have evaluated the use of one or more ERAS intervention against usual care for patients (Table 1). Only randomized controlled trials will be included.

Search strategy
The databases searched will include: EMBASE (OVID, 1947 to June 2012), Medline (OVID, 1948 to June 2012), and Cochrane Central Register of Controlled Trials (Wiley, Issue 1, 2012). The database search will be supplemented by searching for grey literature (i.e. difficult to locate or unpublished material). Specifically, we will search online (e.g., Google), trial registers (e.g., Prospero), and conference abstracts. Searches will be performed with no year or language restrictions. Relevant non-English language articles will be translated. Literature search strategies will be developed by combining medical subject headings (MeSH terms) and appropriate wildcards. If necessary we will contact study authors to identify additional studies. The literature search will be conducted by an information specialist (LP) and peer-reviewed by another information specialist using Peer Review of Electronic Search Strategy (PRESS) [34]. In addition, we will hand search the references of selected studies. See Appendix II.

Study selection
A pilot test of 50 randomly selected citations will be conducted by all authors to verify the inclusion/exclusion criteria. Subsequently, all studies (citations and full text) will be reviewed by two reviewers independently. Conflicts will be resolved by team discussion.

Data collection
Data from included studies will be abstracted in duplicate by two reviewers using a data collection form. The data collection form will include: a. patient characteristics (e.g., mean age, percent gender, number of patients) b. study characteristics (e.g., study design, country of conduct, randomization procedure) c. details of the intervention (e.g., which ERAS intervention was deliveredpatient education, fluid restriction, early mobilization, etc.) d. details of the comparator (e.g., placebo, usual care) e. primary outcome results (e.g., length of stay, complications rate, patient expectations).
The data abstraction form will be pilot tested on a random sample of studies to ensure high inter-rater agreement between reviewers.

Risk of bias assessment (quality)
Two reviewers will independently assess each selected study for the strengths of the research methods and results using the Cochrane Risk of Bias Tool [35]. This tool is comprised of the following six items: selection bias (sequence generation and allocation concealment), performance bias (blinding of participants and personnel), detection bias (blinding of outcome assessment), attrition bias (incomplete outcome data), selective outcome reporting, and other sources of bias. Disagreements will be discussed and resolved by consensus.

Data synthesis
The results of the literature search will be presented in a flow diagram indicating the number of studies screened, the number of studies excluded, and reasons for exclusions. A synthesis of patient and study characteristics will be provided in separate tables including study citation and collected data items. A synthesis of risk bias results will be presented in a table format for each study as well as across studies. Primary outcomes will be synthesized in table format, including a summary of data for each intervention group, effect estimates, and confidence intervals. A separate subgroup analysis will be conducted for length of stay (LOS) based on the procedure and grouped by: endovascular, abdominal approach, extremity, and amputation.
Complication-type will also be grouped by procedure (Table 2). To account for differences between interventions subgroups analyses by intervention will be conducted. If the interventions are too varied, data will not be pooled. If deemed appropriate, a random effects meta-analysis will be conducted. This will be conducted by type of surgery and individual ERAS intervention. Statistical heterogeneity will be examined using the I 2 statistic [36].

Discussion
ERAS involves specified interventions at preoperative, perioperative, and postoperative points of care. Most ERAS approaches have been considered in the context of colorectal surgery. Given the increasing use of multiple yet different aspects of this pathway in vascular surgery, it is timely to systematically review the evidence for their independent or combined outcomes, with a view to implementing them in this clinical setting. We will disseminate the results of this review in an open access scientific journal and will present results at relevant scientific conferences. We expect our results will have important implications for vascular surgeons, anaesthetists, nurses, and other health care professionals when making evidenced-based decisions about the use of ERAS in their daily practice.

Appendix
Appendix I: Major elective vascular procedures