A Systematic Review of Postoperative Pain Outcome Measurements Utilised in Regional Anesthesia Randomized Controlled Trials.
Regional anesthesia is a rapidly growing subspecialty, with a widening spectrum of applications and uses. Despite growth in this area of research, there have been few published regional anesthesia systematic reviews, meta-analyses, Cochrane reviews, or National Institute for Health and Care Excellence (NICE) guidelines exploring pain outcomes. This maybe due to the heterogeneity of outcome variables chosen in regional anesthesia studies, making it difficult to combine and analyse data.
The Cochrane Collaboration, which aims to give the "clinical bottom line" through its reviews, has 39 reviews, which mention regional anesthesia. These reviews commonly cite the outcomes chosen as "incomplete," "poor quality," and "heterogeneous," which impeded the authors' ability to draw meaningful conclusions [1-4]. Additionally, there are four NICE guidelines centered on regional anesthesia [5-8], and of these, only one deals specifically with the use of regional anesthesia to manage surgical or postoperative pain .
Identification of outcomes utilised can subsequently help to create a definitive list of core outcomes, which may guide future researchers when designing studies. This systematic review aimed to explore outcomes utilised in regional anesthesia randomized controlled trials (RCTs) to measure postoperative pain.
We have adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards in this article .
We performed a literature search using three search engines (Medline, Embase, and CINAHL). These databases were searched for RCTs published between 2005 and 2017. The search strategy included manual searching of citations for further relevant articles. The search was initially performed in mid December 2016 and repeated on January 5th 2017. An example of the exact search terms used for each database is included in Appendix A. The review was limited to published English language RCTs exploring regional anesthesia, with a primary outcome of postoperative pain. Articles were included if published between 2005 and 2017, in one of the top 20 impact factor journals (Appendix B, Table 4). Since it was felt that the assessment of pain within the adult population is significantly different to the pediatric and obstetric populations, this review was limited only to adult studies (participants aged 18 years and over).
The selected studies were analysed by two of the authors (E. Pushpanathan and T. Setty). Each study was read and the following data were extracted and tabulated: authors, year of publication, postoperative pain outcome measures utilised, times of postoperative pain assessment, nerve block studied, and personnel collecting the data. The two primary outcomes explored in this systematic review were the type of pain outcome measured and the time of measurement.
The quality of studies included in this systematic review was evaluated using the Cochrane Collaboration's tool for assessing risk of bias . Areas of methodological quality assessed included concealment of allocation, random sequence generation, blinding of the assessors and participants, and accounting for all subjects. Overall quality was graded as low (low risk of bias), high (high risk of bias), or unclear risk of bias for each domain entry . The quality of each study was also assessed using the Jadad score, which examines withdrawals, blinding, and randomization of a study , although studies were not excluded on the basis of this assessment. At least two individuals extracted the study data independently utilizing a standardised review protocol and recorded the information on a data spreadsheet. Differences were resolved by reexamination of the original manuscripts and by discussion. The data were then entered into a Microsoft Excel for Mac 2016 spreadsheet (Microsoft Corporation, Redmond, WA) by one of the authors (E. Pushpanathan) and checked by a second investigator (T. Setty).
The search identified 407 articles. One author screened the titles and abstracts of these articles, and 308 were excluded. Two authors reviewed the full text of the remaining 99 articles. Of those excluded, 20 were duplicates and 18 were not RCTs. Of the remaining excluded articles, 5 were pediatric studies, 2 were obstetric, 3 were systematic reviews or meta-analyses, 2 were foreign language, 7 did not have postoperative pain as a primary outcome, and 11 were abbreviated studies in supplements so lacked sufficient detail. The results of the literature search are summarised in Figure 1. Thirty-one articles met the inclusion criteria and were included in this systematic review [12-42]. A detailed description of the pain outcomes utilised and timings of measurements in the included studies is provided in Table 1. Table 2 summarises the number of studies utilizing each pain outcome identified from included studies. Median Jadad score of included studies was 3 (range 2-5). The majority of studies demonstrated a low risk of bias in the 7 domains. A summary of risk of bias assessment is provided in Figure 2.
3.1. Postoperative Pain Measurement Tool. Fifteen different outcome measures in total were used in the 31 included studies to assess postoperative pain. The outcome measures utilised in the included studies are summarised in Table 2. The majority of studies (27/31) utilised two or more pain outcomes. The most commonly used outcome measures were numerical grading of pain/numerical reporting scale (NRS) out of 10 (16 studies) [12, 17, 20-24, 27-29, 32-35, 38, 40], opioid consumption (16 studies), and visual analogue scale 10 cm (VAS; 12 studies) [13-16, 25, 26, 31, 36, 37, 39, 41, 42]. Other than reporting total opioid consumption, analgesia usage was also measured with the following outcomes: nonopioid analgesic requirement [14, 16, 32, 33, 36], total supplementary analgesic requirement [34, 35], and cumulative opioid consumption [26, 37]. Other pain outcome measures utilised included: time to first episode of pain [22, 33] and first analgesia or opioid request [18, 28-30, 35-37]. If a study did not use a scoring system to rate pain, the need for analgesia was utilised instead as an outcome measure. There was an evident understanding amongst the selected studies that pain may be worse on movement with separate pain scores (NRS or VAS) taken on activity in 10 of the included studies (Table 2). In the studies that utilised a scoring system to measure pain, there were two groups; those that reported scores at individual time points [12, 14-16, 19, 21, 23-26, 28, 29, 31, 32, 34-37, 39-42] and studies that recorded the worst (or maximum) pain score during the study period [17, 20, 22, 27, 33]. Average pain scores were reported in only one study .
3.2. Time of Measurement. Time of measurement of pain outcomes also varied with a total of 51 different time points utilised in the 31 studies (Table 1). The time points ranged from immediately following surgery [20,26,27,29, 31, 34, 37,41] to 12 months postoperatively . Intervals between measurements ranged from every 5 minutes  to 6 months . Twenty-two out of 31 of the studies (71%) only evaluated pain over the first 24 hours postoperatively [12, 14, 16, 17, 19, 20, 22-24, 26, 27, 29, 31-34, 36, 38-42].
3.3. Nerve Blocks Studied. A variety of nerve blocks were studied (16 in total), which are summarised in Table 3 and may indicate which blocks were seen as important over the study period. Six studies explored continuous infusions [12, 16, 20, 23, 29, 38] with either peripheral nerve or epidural infusions. The remaining studies evaluated single-shot peripheral nerve blocks.
3.4. Personnel Collecting Data. Twelve out of the 31 included studies (39%) used an independent or blinded assessor or independent assessment (i.e., postal survey) to assess patients' pain [12, 14, 17, 19, 22, 25-27, 33, 34, 36, 42].
3.5. Acute Pain Studies. All but two of the included studies focused on acute pain outcomes. Choi et al. assessed pain outcomes of acute and chronic pain  NRS at 4.5 months postoperatively and Wegener et al.  looked at the WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) score and VAS at two different time points (3 months and 12 months).
This systematic review demonstrates that postoperative pain in regional anesthesia RCTs is reported inconsistently. The 31 studies included in this review utilised 15 different types of postoperative pain outcomes, measured at 51 different time points. Therefore at present, there appears to be multiple analyses of different nerve blocks in different centers using different acute pain outcome measures.
Heterogeneity in pain outcomes chosen in the included studies was high. One of the difficulties in deciding which pain outcomes to study in regional anesthesia trials is that there is no reliable method of objectively measuring postoperative pain . Physiological parameters, such as heart rate and skin conductance, appear to correlate poorly with pain levels [44, 45]. Instead, pain is often measured by patient-reported intensity, surrogate measures such as the use of supplemental analgesia, or measures of the impact of pain on functioning including the following: sleep, coughing, or ability to perform activities of daily living. Each of these assessment strategies has strengths and limitations, which are demonstrated in this review by the majority of studies using two or more outcome measures to assess pain.
The visual analogue scale (VAS) is a widely used tool to assess postoperative pain. It is considered by some to be more sensitive to fine changes in pain score than numerical scales and four point scales . It also has been shown to demonstrate generally high usability and acceptance; however, elderly patients have been found to not engage with this tool as well as younger patients, since lengthy explanations may be necessary and inconsistent marking along the line has previously been reported . The NRS is another widely used tool to measure pain. Both VAS and NRS are one-dimensional pain tools that are easy to measure and largely reproducible, and thus it may explain why these are often chosen in preference to lengthier multidimensional tools, such as the McGill Pain Questionnaire. Since NRS is a verbal tool, requiring no writing or marking (in contrast to VAS), and is simple to perform by clinical and research team members , it should perhaps be considered as an ideal core outcome rather than VAS in studies involving elderly age groups.
Total opioid consumption over the study period (excluding daily and cumulative opioid consumption) was another popular outcome choice, which was utilised in 12 of the 31 studies reporting postoperative pain in this review. This outcome can be interpreted in different ways. A higher total opioid consumption value over a study period is presumed to indicate a higher pain state, necessitating requirement for supplemental opioid-based analgesia. Total opioid consumption could also reflect average pain scores (either NRS or VAS), with higher scores indicating greater opioid requirement. The psychological factors involved in patients requesting additional analgesia warrant further consideration. This involves evaluation of anticipated pain outcome with and without further analgesia, and in order for the request to be made, the patient must feel the treatment of pain outweighs the potential risk of side effects from the drug. This has been shown to be a key decision-making factor when patients are in pain . Total opioid consumption as an outcome may therefore result in patients with different pain states, intensities, and satisfaction levels with analgesia being inappropriately grouped together.
Regional anesthesia is gaining popularity, partly due to improvements in safety and success attributed to ultrasound-guided techniques . The Sprint National Anaesthesia Project (SNAP-1) examined patient-reported outcomes related to satisfaction with anesthesia . Anxiety was found to be the worst part of the perioperative experience. With regard to anesthesia, specific reasons for dissatisfaction: thirst, drowsiness, pain at the surgical site, and hoarseness, were found to be among the most troubling for patients. Regional anesthesia (as a whole) was found to be associated with a reduced burden of side effects. It is unclear what level of pain correlates to adequate patient satisfaction in this population. Nine studies included in this systematic review utilised outcomes consisting of a variant of determinant of effective block duration such as time to first pain or time to first analgesic/opioid request. This suggests that some researchers value the importance of duration of patient being pain-free or experiencing a low enough pain level not to require additional analgesia. However, it should also be noted that a prolonged, dense block may not be in the patients' best interests and may be associated with worse patient satisfaction in this population.
Adequate assessment of pain, using validated tools appropriate to the population or individual, is an essential prerequisite of successful pain management. It has been shown in many countries that inadequate pain assessment is common, with resultant failings in management of pain . Although our review may prove helpful to clinicians and researchers in the future, by summarizing some of the available measures, there are still unanswered questions in this field. In order to assimilate multiple studies with meta-analysis and to derive meaningful clinical conclusions, this review highlights the need for the formulation of a minimum set of outcomes that can be used in future regional anesthesia studies. Use of such a "core set of outcomes" would allow for comparison of outcomes from studies. The COMET or (Core Outcome Measures in Effectiveness Trials) group is a United Kingdom initiative set up in 2010 in response to disjointed outcome measures in clinical research as a whole . Their aim is to standardize outcomes and provide a database from which researchers can access existing outcome sets to design future trials. Specific analysis into the subset of patients undergoing regional anesthesia requires further research. The perspective of patients of the correct demographic ("key stakeholders") must be considered when deciding core outcomes for postoperative pain assessment in regional anesthesia. This would require exploration of what patients expect following regional anesthesia, including pain expectations following surgery performed with regional anesthesia.
The core outcome set for chronic pain studies may help researchers decide which outcomes to utilize in future regional anesthesia pain studies. A core outcome set of six outcomes for chronic pain was formalised in 2005 by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) group . This group formalised outcomes to be used for physical functioning, emotional functioning, participant rating for improvement and satisfaction, symptoms and adverse events, and participant disposition, as well as for the assessment of pain. With regards to pain, recommendations included an 11 point 0-10 scale, usage of rescue analgesics, and categorical scale if the patient was unable to use a verbal scale. This systematic review has shown that the IMMPACT recommended pain outcomes for chronic pain are also the most commonly used in the acute pain setting in regional anesthesia RCTs. The 2005 IMMPACT recommendations, which are primarily for improving clinical trial methodology of chronic pain treatments, do not seem to have made any impact on outcomes in regional anesthesia efficacy studies. This may be because the pain outcomes considered clinically important in recovery following elective surgery are different to those important in patients with chronic pain. Acute pain can be reliably assessed, both at rest (important for comfort) and during movement (important for function and risk of postoperative complications), with one-dimensional tools such as NRS or VAS. Chronic pain assessment however and its impact on physical, emotional, and social functions require multidimensional qualitative tools and health-related quality of life instruments . For example, it should be noted that while VAS was found to be one of the most commonly utilised acute pain outcomes identified in this review, it was omitted as an assessment for chronic pain outcomes.
When deciding what should be a "core outcome set," one must consider if there is an implied core set or if there are outcomes that are chosen more commonly among regional anesthesia studies. Until a core outcome set for regional anesthesia pain studies has been formulated, researchers may wish to consider utilizing the most commonly used outcomes identified in this review in order to allow for comparisons between existing data in the literature. It should however be noted that this assumes that the most commonly used outcomes represent what clinicians and researchers believe to be the most important. Based on frequency of utilization, this review suggests that the core outcomes for regional studies exploring acute pain should include NRS (verbal out of 10) at rest, NRS on activity, VAS at rest, total opioid consumption over the study period, analgesic consumption, and time to first analgesic request. The most commonly utilised time points of pain outcome data measurement in the descending order of frequency were 24, 4, 6, 12, and 48 hours postoperatively.
This review does have some limitations. Restricting included RCTs to English language studies may have reduced the number of clinically useful studies analysed. Additionally, the restriction to the top 20 impact factor journals may not reflect the outcome measures utilised in the majority of regional anesthesia studies. This did however serve as a marker of study quality and peer review, which we felt was required in this review. However, there are always risks inherent in limiting groups to be studied. The year of publication of included studies is important to note, and established blocks such as femoral nerve blocks may have already been extensively studied prior to 2005. Use of ultrasound guidance may have made some small differences to pain assessment outcome choice and the debate surrounding adductor canal versus femoral nerve block may continue; however, 2005 to 2017 is a relatively short period of time for major changes in clinical practice to have occurred. We limited the search to articles published over this 12-year period as our intention was to provide the reader with information regarding regional anesthesia studies that would be most relevant to current practice. Finally, although we have attempted to locate all relevant articles by using a robust search methodology, it is possible that with a review of this size, some relevant articles may have been missed. Furthermore, since these studies explore different peripheral nerve and plexus blocks, this may make it more difficult to derive an implied core outcome set from the included group of studies. We appreciate that different surgeries have different temporal pain profiles. Some surgeries for example may peak in pain immediately after surgery, whereas others may have pain that peaks when the nerve block wears off or during days following surgery. However, despite the apparent heterogeneity among the included studies, the vast majority of the RCTs included utilised generic outcomes and only one study used a scoring system specific to the type of surgery performed (the Western Ontario and McMasters Universities Osteoarthritis Index) [25, 54].
In summary, this robust review of the postoperative pain outcomes used in regional anesthesia RCTs between 2005 and 2017 demonstrates significant heterogeneity in choice of outcomes and times of measurements utilised. These findings represent a starting point for further work into developing a core outcome set for future regional anesthesia studies.
A: Literature Search Terms
The basic components of the search were as follows:
Postoperative pain (ti.ab) AND regional anaesthesia (ti.ab) AND randomised controlled trial (ti.ab) AND top 20 impact factor journals (j.n.) [limited to 2005-2017]
These were the search terms used in OpenAthens to formulate the final search:
(1) EMBASE, Medline, CINAHL; (((postoperative pain adj4 pain*) OR (post-operative adj4 pain*) OR postoperative-pain* OR (post* NEAR pain*) OR (postoperative adj4 analgesi*) OR (post-operative adj4 analgesi*) OR (post-operative adj4 analgesi*))) ti.ab
(2) EMBASE, Medline, CINAHAL; (((post-surgical adj4 pain*) OR ("post-surgical" adj4 pain*) OR (post-surgery adj4 pain*))) ti.ab
(3) EMBASE, Medline, CINAHL; ((("pain-relief after surgery") OR ("pain following surg") OR ("pain control after"))) ti.ab
(4) EMBASE, Medline, CINAHL; ((("post surg*" OR post-surg*) AND (pain* OR discomfort))) ti.ab
(5) EMBASE, Medline, CINAHL; (((pain* adj4 "after surg$") OR (pain* adj4 "follow* operat") OR (pain* adj4 "follow* surg*"))) ti.ab
(6) EMBASE, Medline, CINAHL; (((analgesi* adj4 "after surg*") OR (analgesi* adj4 "after operat*") OR (analgesi* adj4 "follow* operat*") OR (analgesi* adj4 "follow* surg*"))) ti.ab
(7) 1 OR 2 OR 3 OR 4 OR 5 OR 6
(8) "Anesthesia, Conduction" ti.ab
(9) "Anesthesia, Spinal" ti.ab
(10) "Analgesi, Epidural" ti.ab
(11) "Anesthesia, Epidural" ti.ab
(12) "Anesthesia, Caudal" ti.ab
(13) "Nerve Block" ti.ab
(14) "regional anesthesia" ti.ab
(15) "conduction anesthesia" ti.ab
(16) "spinal block" ti.ab
(17) "Epidural block" ti.ab
(18) "epidural anesthesia" ti.ab
(19) "plexus block" ti.ab
(20) (plexus AND block) ti.ab
(21) (bier AND block) ti.ab
(22) 8 OR 9 OR 10 OR 11 OR 12 OR 13 OR 14 OR 15 OR 16 OR 17 OR 18 OR 19 OR 20 OR 21
(23) ("randomi?ed controlled trial") OR ("randomi?ed trial") OR ("controlled trial") ti.ab
(24) EMBASE, Medline, CINAHL; ("anesthesiology" OR "pain" OR "british journal of anaesthesia" OR "pain physician"OR "anesthesia and analgesia" OR "anaesthesia" OR "regional anesthesia and pain medicine" OR "journal of neurosurgical anesthesia" OR "european journal of anaesthesia" OR "european journal of pain" OR "canadian journal of anesthesia" OR "clinical journal of pain" OR "pain practice" OR "acta anaesthesia scandinavia" OR "Minerva anesthesiology" OR "journal of clinical monitoring and computing" OR "current opinion anesthesiology" OR "journal of cardiothoracic and vascular anaesthesia" OR "BMC anesthesiology").jn
(25) 7 AND 22 AND 23 AND 24 [Limit to: Publication Year 2005-2017]
B: Top Impact Factor Journal List
These are the current impact factors of all the top international anesthesia journals as of 21st October 2015  and were used as limiting functions in the literature review.
Conflicts of Interest
No study-related external funding or competing interests declared.
All authors are responsible for data collection and data analysis and wrote the manuscript.
Received 24 March 2018; Accepted 24 June 2018; Published 29 July 2018
Please Note: Illustration(s) are not available due to copyright restrictions.
 A. Atchabahian, G. Schwartz, C. Hall, C. Lajam, and M. Andreae, Regional Analgesia for Improvement of Long-Term Functional Outcome after Elective Large Joint Replacement, The Cochrane Collaboration, London, UK, 2015.
 M. Andreae and D. Andreae, Local Anaesthetics and Regional Anaesthesia for Preventing Chronic Pain after Surgery, The Cochrane Collaboration, London, UK, 2012.
 M. Parker, H. Handoll, and R. Griffiths, Anaesthesia for Hip Fracture in Adults, The Cochrane Collaboration, London, UK, 2004.
 B. Afolabi and E. A. Foluso, Regional versus General Anaesthesia for Caesarean Section, The Cochrane Collaboration, London, UK, 2012.
 NICE, Ultrasound-Guided Regional Nerve Block (ipg285), National Institute of Clinical Excellence Guidance, London, UK, 2009.
 NICE, Hip Fracture: Managment, National Institute of Clinical Excellence Guidance, London, UK, 2011.
 NICE, Hip Fracture in Adults qs16, National Institute of Clinical Excellence Guidance, London, UK, 2012.
 NICE, Fractures (Non-Complex): Assessment and Managment (ng38), National Institute of Clinical Excellence Guidance, London, UK, 2016.
 A. Liberati, D. G. Altman, J. Tetzlaff et al., "The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration," British Medical Journal, vol. 339, no. 1, p. b2700, 2009.
 J. P. T. Higgins, D. G. Altman, and J. A. C. Sterne, Chapter 8: Assessing Risk of Bias in Included Studies, John Wiley & Sons Ltd., London, UK, 2011.
 A. R. Jadad, R. A. Moore, D. Carroll et al., "Assessing the quality of reports of randomized clinical trials: is blinding necessary?," Controlled Clinical Trials, vol. 17, no. 1, pp. 1-12, 1996.
 A. L. Ambrosoli, L. Guzzeti, M. Chiaranda, S. Cuffari, M. Gemma, and G. Cappelleri, "A randomised controlled trial comparing two popliteal nerve catheter tip positions for postoperative analgesia after day-case hallux valgus repair," Anaesthesia, vol. 71, no. 11, pp. 1317-1323, 2016.
 H. Andersen, J. Gym, L. Moller, B. Christensen, and D. Zaric, "Continuous saphenous nerve block as supplement to single dose local infiltration analgesia for postoperative pain management after total knee arthroplasty," Regional Anaesthesia and Pain Medicine, vol. 38, no. 2, pp. 106-111, 2013.
 N. Bharti, D. K. Sardana, and I. Bala, "The analgesic efficacy of dexmedetomidine as an adjunct to local anesthetics in supraclavicular brachial plexus block: a randomized, controlled trial," Anesthesia and Analgesia, vol. 121, no. 6, pp. 1655-1660, 2015.
 M. Boussofara, M. Carles, M. Raucoules-Aime, M. R. Sellam, and J. L. Horn, "Effects of intrathecal midazolam on postoperative analgesia when added to a bupivicaine-clonidine mixture," Regional Anaesthesia and Pain Medicine, vol. 31, no. 6, pp. 501-505, 2006.
 X. Capdevilla, C. Dadure, S. Bringuier et al., "Effect of patient controlled perineural analgesia on rehabilitation and pain after ambulatory orthopaedic surgery: a multicentre randomized trial," Anesthesiology, vol. 105, no. 3, pp. 566-573, 2006.
 S. Choi, T. O'Hare, J. Gollish et al., "Optimizing pain and rehabilitation after knee arthroplasty: a two-center, randomized trial," Anesthesia and Analgesia, vol. 123, no. 5, pp. 1316-1324, 2016.
 M. Diakomi, M. Papaioannou, A. Mela, E. Kouskoni, and A. Makris, "Preoperative fascia iliaca compartment block for positioning patients with hip fractures for central nervous blockade: a randomized trial," Regional Anaesthesia and Pain Medicine, vol. 39, no. 5, pp. 394-398, 2014.
 N. M. Elkassabany, S. Antosh, M. Ahmed et al., "The risk of falls after total knee arthroplasty with the use of a femoral nerve block versus an adductor canal block: a double-blinded randomized controlled study," Anesthesia & Analgesia, vol. 122, no. 5, pp. 1696-1703, 2016.
 M. J. Fredrickson, C. M. Ball, and A. J. Dalgleish, "Posterior versus anterolateral approach interscalene catheter placement: a prospective randomized trial," Regional Anaesthesia and Pain Medicine, vol. 36, no. 2, pp. 125-133, 2011.
 G. Fritsch, T. Danninger, K. Allerberger, A. Tsodikov, and T. K. Felder, "Dexmedetomidine added to ropivicaine extends the duration of interscalene brachial plexus blocks for elective shoulder surgery when compared with ropivicaine alone: a single-centre, prospective, triple-blind, randomized controlled trial," Regional Anaesthesia and Pain Medicine, vol. 39, no. 1, pp. 37-47, 2014.
 W. Zhai, X. Wang, Y. Rong, M. Li, and H. Wang, "Effects of a fixed low-dose ropivicaine with different volume and concentrations on interscalene brachial plexus block: a randomized controlled trial," BMC Anesthesiology, vol. 16, no. 1, p. 80, 2015.
 M. Wongyingsinn, G. Baldini, P. Charlebois, S. Liberman, B. Stein, and F. Carli, "Intravenous lidocaine versus thoracic epidural analgesia: a randomized controlled trial in patients undergoing laparoscopic colorectal surgery using an enhanced recovery program," Regional Anaesthesia and Pain Medicine, vol. 36, no. 3, pp. 241-248, 2011.
 J. T. Wegener, B. Van Ooij, C. Van Dijket al., "Value of single-injection or continuous sciactic nerve block in addition to a continuous femoral nerve block in patients undergoing total knee arthroplasty: a prospective, randomized, controlled trial," Regional Anaesthesia and Pain Medicine, vol. 36, no. 5, pp. 481-488, 2011.
 J. T. Wegener, B. Van, C. Van, S. A. Karayeva, and M. W. Hollman, "Long-term pain and functional disability after total knee arthroplasty with and without single-injection or continuous sciatic nerve block in addition to continuous femoral nerve block: a prospective, 1 year follow-up of a randomized controlled trial," Regional Anaesthesia and Pain Medicine, vol. 38, no. 1, pp. 1098-7339, 2013.
 K. H. Thybo, H. Schmidt, and D. Hagi-Pedersen, "Effect of lateral femoral cutaneous nerve block on pain after total hip arthroplasty: a randomised, blinded, placebo-controlled trial," BMC Anesthesiology, vol. 16, no. 1, p. 21, 2016.
 O. Stundner, M. Meissnitzer, C. M. Brummett et al., "Comparison of tissue distribution, phrenic nerve involvement, and epidural spread in standard vs low-volume ultrasound-guided interscalene plexus block using contrast magnetic resonance imaging: a randomized, controlled trial," British Journal of Anaesthesia, vol. 116, no. 3, pp. 405-412, 2016.
 R. Subramanyam, V. Vaishnave, V. W. Chan, D. Brown-Shreves, and R. Brull, "Lateral versus medial needle approach for ultrasound-guided supraclavicular block: a randomized controlled trial," Regional Anaesthesia and Pain Medicine, vol. 36, no. 4, pp. 387-392, 2011.
 K. Schoenmakers, M. Fenten, J. Louwerens, J. Scheffer, and R. Stiensra, "The effects of adding epinephrine to ropivicain for popliteal nerve block on the duration of postoperative analgesia: a randomized controlled trial," BMC Anesthesiology, vol. 15, no. 1, pp. 1471-2253, 2015.
 R. Sindjelic, G. Vlajkovic, L. Davidovic, D. Markovic, and D. Markovic, "The addition of fentanyl to local anesthetics affects the quality and duration of the cervical plexus block: a randomized, controlled trial," Anesthesia and Analgesia, vol. 111, no. 1, pp. 234-237, 2010.
 K. Sato, T. Adachi, N. Shirai, and N. Naoi, "Continuous versus single injection sciatic nerve block added to continuous femoral nerve block for analgesia after total knee arthroplasty: a prospective, randomised, double-blind study," Regional Anaesthesia and Pain Medicine, vol. 39, no. 3, pp. 225-229, 2014.
 M. Sawhney, H. Mehdian, B. Kashin et al., "Pain after unilateral total knee arthroplasty: a prospective randomized controlled trial examining the analgesic effectiveness of a combined adductor canal peripheral nerve block with periarticular infiltration versus adductor canal nerve block alone versus periarticular infiltration alone," Anesthesia and Analgesia, vol. 122, no. 6, pp. 2040-2046, 2016.
 E. Salviz, D. Xu, A. Frulla et al., "Continuous interscalene block in patients having outpatient rotator cuff repair surgery: a prospective randomized trial," Anesthesia and Analgesia, vol. 117, no. 6, pp. 1485-1492, 2013.
 M. Nagafuchi, T. Sato, T. Sakuma et al., "Femoral nerve blocksciatic nerve block vs. femoral nerve block-local infiltration analgesis for total knee arthroplasty: a randomized controlled trial," BMC Anesthesiology, vol. 15, no. 1, p. 182, 2015.
 E. C. Moura, C. A. de Oliveira Honda, R. C. Bringel, C. Leal Pda, J. Filho Gde, and R. K. Sakata, "Minimum effective concentration of bupivicaine in ultrasound-guided femoral nerve block after arthroscopic knee meniscectomy: a randomized, double-blind, controlled trial," Pain Physician, vol. 19, no. 1, pp. E79-E86, 2016.
 S. Kulhari, N. Bharti, I. Bala, S. Arora, and G. Singh, "Efficacy of pectoral nerve block versus thoracic paravertebral block for postoperative analgesia after radical mastectomy: a randomized controlled trial," British Journal of Anaesthesia, vol. 117, no. 3, pp. 382-386, 2016.
 V. S. Karthikeyan, S. C. Sistla, A. S. Badhe et al., "Randomized controlled trial on the efficacy of bilateral superficial cervical plexus block in thyroidectomy," Pain Practice, vol. 13, no. 7, pp. 539-546, 2013.
 M. Hamdani, O. Chassot, and R. Fournier, "Ultrasound-guided continuous interscalene block: the influence of local anesthetic background delivery method on postoperative analgesia after shoulder surgery: a randomized trial," Regional Anaesthesia and Pain Medicine, vol. 39, no. 5, pp. 387-393, 2014.
 Z. K. Bengisun, P. Ekmekci, B. Akan, A. Korotlu, and F. Tuzuner, "The effect of adding dexmedetomidine to levobupivicaine for interscalene block for postoperative pain managment after arthroscopic shoulder surgery," Clinical Journal of Pain, vol. 30, no. 12, pp. 1057-1061, 2014.
 J. T. YaDeau, T. Tedore, E. Goytizolo et al., "Lumbar plexus blockade reduces pain after hip arthroscopy: a prospective randomized controlled trial," Anesthesia and Analgesia, vol. 115, no. 4, pp. 968-972, 2012.
 Z. Siddiqui, M. Cepeda, W. Denman, R. Schumann, and D. Carr, "Continuous lumbar plexus block provided improved analgesia with fewer side effects compared with systemic opioids after hip arthroplasty: a randomized controlled trial," Regional Anaesthesia and Pain Medicine, vol. 32, no. 5, pp. 393-398, 2007.
 J. S. Kim, J. Lee, E. Y. Soh et al., "Analgesic effects of-ultrasound-guided serratus-intercostal plane block and ultrasound-guided intermediate cervical plexus block after single-incision transaxillary robotic thyroidectomy: a prospective, randomized, controlled trial," Regional Anesthesia and Pain Medicine, vol. 41, no. 5, pp. 584-588, 2016.
 J. Younger, R. McCue, and S. Mackey, "Pain outcomes: A brief review of the instruments and techniques," Current Pain and Headache Reports, vol. 13, no. 1, pp. 39-43, 2009.
 P. Bossart, D. Fosnocht, and E. Swanson, "Changes in heart rate do not correlate with changes in pain intensity in emergency department patients," Journal of Emergency Medicine, vol. 32, no. 1, pp. 19-22, 2007.
 D. Harrison, S. Boyce, and P. Loughnan, "Skin conductance as a measure of pain and stress in hospitalised infants," Early Human Developement, vol. 82, no. 9, pp. 603-608, 2006.
 R. A. Seymour, "The use of pain scales in assessing the efficacy of analgesics in post-operative dental pain," European Journal of Clinical Pharmacology, vol. 23, no. 5, pp. 441-444, 1982.
 M. A. Williams, M. T. Oberst, B. C. Bjorklund, H. A. Kruse, and S. A. Coggon, "Response formats in questionnaires used with older adults," in Proceedings of the 12th Annual Midwest Nursing Research Society Conference, Wichita, KS, USA, December 1988.
 T. J. Gan, D. A. Lubarsky, E. M. Flood et al., "Patient preferences for acute pain treatment," British Journal of Anaesthesia, vol. 92, no. 5, pp. 681-688, 2004.
 F. Mirza and A. R. Brown, "Ultrasound-guided regional anesthesia for procedures of the upper extremity," Anesthesiology Research and Practice, vol. 2011, Article ID 579824, 6 pages, 2011.
 E. Walker, M. Bell, T. M. Cook, M. P. Grocott, and S. R. Moonesinghe, "Patient reported outcome of adult perioperative anaesthesia in the United Kingdom: a cross-sectional observational study," British Journal of Anaesthesia, vol. 117, no. 6, pp. 758-766, 2016.
 H. Breivik, P. Borchgrevink, S. Allen et al., "Assessment of pain," British Journal of Anaesthesia, vol. 101, no. 1, pp. 17-24, 2008.
 "Core outcome measures in effectiveness trials initiative," September 2015, http://www.comet-initiative.org/about/ overview.
 R. Dworkin, D. Turk, J. Farrar et al., "Core outcome measure for chronic pain clinical trials: IMMPACT recommendations," Pain, vol. 113, no. 1, pp. 9-19, 2005.
 N. Bellamy, J. Campbell, J. Stevens, L. Pilcher, C. Stewart, and Z. Mahmood, "Validation study of a computerized version of the Western Ontario and McMaster Universities VA3.0 Osteoarthritis Index," Journal of Rheumatology, vol. 24, no. 12, pp. 2413-2415, 1997.
 M. Wang, J. P. Smith, R. Choy et al., "Impact factor list 2014," July 2018, http://www.citefactor.org/journal-impact-factorlist-2014.html.
E. Pushpanathan, (1) T. Setty, (2) B. Carvalho, (3) and P. Sultan (4)
(1) Department of Anaesthesia, Guy's and St. Thomas' NHS Foundation Trust, London, UK
(2) Department of Anaesthesia, University College Hospitals London NHS Foundation Trust, London, UK
(3) Department of Anesthesia, Stanford University School of Medicine, Stanford, CA, USA
(4) Department of Anaesthesia, University College Hospitals London NHS Foundation Trust, University College London, London, UK
Correspondence should be addressed to E. Pushpanathan; firstname.lastname@example.org
Academic Editor: Enrico Camporesi
Caption: FIGURE 1: Summary of literature search and included studies.
Caption: FIGURE 2: Risk of bias assessment in included studies.
TABLE 1: Summary of measurement timings of pain outcomes utilised in included studies. Author/year Country Measurement tool of study Ambrosoli Not NRS (not stated; 0-10) et al.  stated NRS at rest (0-10) NRS on activity (0-10) Number of occasions sleep was disturbed by pain Andersen Denmark Worst pain during knee et al.  movement VAS (10 cm) at rest Time from surgery to VAS score 3 (not stated) Sleep disturbance due to pain (yes/no) Total opioid consumption Bengisun Turkey VAS (10 cm; not stated) et al.  Bharti VAS (10 cm; not stated) et al.  India Total analgesic requirement (opiate and nonopiate) Boussofara Tunisia VAS (10 cm; not stated) et al.  Total opioid consumption Capdevilla France VAS (10 cm; not stated) et al.  Total analgesic consumption (nonopiate) Choi Canada NRS on activity (0-10) et al.  Total opioid consumption NRS at rest (0-10) NRS on activity (0-10) Worst NRS (0-10) NRS (0-10; not stated) Diakomi Greece Time to first IV et al.  opioid request (hours) Total opioid consumption Elkassabany USA Pain scores (type of pain score not stated) et al.  Pain scores (type of pain score not stated) Pain scores (aPS-POQ-R) Total opioid consumption Fredrickson New NRS (not stated; 0-10) et al.  Zealand Fritsch Austria NRS at rest (0-10) et al.  NRS on activity (0-10) Hamdani Switzerland Average pain score et al.  (NRS; 0-10) (not stated) Average pain score (NRS; 0-10) (not stated) Total opioid consumption Total opioid consumption Maximum pain score (NRS; 0-10) (not stated) Maximum pain score (NRS; 0-10) (not stated) Karthikeyan India VAS (10 cm) et al.  (not stated) Time to first analgesic request Total analgesic consumption (opioid consumption) Kim Republic VAS (10 cm; not stated) et al.  of Korea Kulhari Not stated Time to first rescue et al  analgesia Total analgesic consumption (opioid consumption) VAS (10 cm; not stated) Moura Brazil NRS (not stated; 0-10) et al.  Total dose of supplementary analgesia (opioid and nonopioid) Time to first analgesic supplementation Nagafuchi Japan NRS (not stated; 0-10) et al.  Total dose of diclofenac Salviz USA Time to first pain et al.  Analgesic consumption (opioid) Maximum NRS (not stated; 0-10) Sawhney Canada NRS on activity (0-10) et al.  NRS at rest and with knee bending (0-10) NRS on activity (0-10) NRS at rest and with knee bending (0-10) Analgesic consumption (opioid and nonopioid) per day Sato Japan VAS (10 cm) at rest et al.  Morphine consumption Siddiqui USA VAS (10 cm) at rest et al.  Sindjelic Serbia Time to first analgesic et al.  request Total opioid consumption Schoenmakers Netherlands Time to first et al.  analgesic request NRS at rest (0-10) NRS on activity (0-10) Subramanyam Canada NRS (not stated; 0-10) et al.  Time to first analgesic request NRS at rest (0-10) Stundner Austria NRS on activity (0-10) et al.  Thybo Denmark VAS (10 cm) during et al.  30[degrees] hip flexion Pain at rest VAS (10 cm) and during 30[degrees] hip flexion Pain at rest VAS (10 cm) and during 30[degrees] hip flexion Pain at rest VAS (10 cm) and during 30[degrees] hip flexion Pain at rest VAS (10 cm) and during 30[degrees] hip flexion Pain at rest VAS (10 cm) and during 30[degrees] hip flexion Pain at rest VAS (10 cm) and during 30[degrees] hip flexion Pain at rest VAS (10 cm) and during 30[degrees] hip flexion Cumulative oxycodone consumption Wegener Netherlands WOMAC score et al.  VAS (10 cm) Oxford knee score (inc. pain) Wegener Netherlands NRS at rest (0-10) et al.  NRS on mobilisation 0-10) Total morphine consumption Wongyingsinn Canada NRS at rest (0-10) et al.  NRS on walking (0-10) NRS on coughing (0-10) NRS at rest (0-10) Ya Deau USA NRS on movement (0-10) et al.  Zhai Not stated NRS at rest (0-10) et al.  Worst NRS (0-10) Time of first shoulder pain Author/year Time measured Nerve block Ambrosoli 4 hours post-op Sciatic nerve catheter et al.  Upon discharge 24 hours 48 hours 24 hours 48 hours 24 hours 48 hours Andersen On day of surgery Saphenous nerve block et al.  Hours D1 post-op D2 post-op D3 post-op 48 hours Bengisun 2 hours post-op et al.  4 hours post-op Interscalene block 6 hours post-op 12 hours post-op 24 hours post-op Bharti Every 30 min for 2 hours Supraclavicular brachial et al.  Every 1 hour for 6 hours plexus block Every 2 hours for 12 hours 24 hours post-op 24 hours post-op Boussofara Every 15 min post-op whilst Spinal anaesthetic block et al.  in PACU Whilst in PACU Capdevilla 10 min post-op Interscalene and et al.  1 hour post-op popliteal infusions 4 hours post-op 12 hours post-op AM D1 post-op during physiotx AM D2 post-op during physiotx AM D3 post-op during physiotx AM D4 post-op during physiotx Over 72 hours Choi AM D2 post-op Femoral nerve block et al.  continuous versus single 48 hours AM D1 post-op D1 post-op D1 post-op 4.5 months post-op Diakomi No. of hours Fascia iliaca block et al.  Over first 24 hours Elkassabany Before physiotherapy Femoral nerve block versus adductor canal block et al.  After physiotherapy At 24 hours AM D1 post-op AM D2 post-op Fredrickson Emergence Interscalene catheters et al.  Worst in 24 hours on movement Worst in 24 hours at rest Worst in second 24 hours on movement Worst in second 24 hours at rest Fritsch 4 hours post-op Interscalene brachial et al.  6 hours post-op plexus block 8 hours post-op 10 hours post-op 12 hours post-op 14 hours post-op 4 hours post-op 6 hours post-op 8 hours post-op 10 hours post-op 12 hours post-op 14 hours post-op Hamdani Over first 24 hours Continuous et al.  interscalene Over first 48 hours Over first 24 hours Over first 48 hours Over first 24 hours Over first 48 hours Karthikeyan Admission to PACU Bilateral cervical et al.  2 hours post-op plexus block 4 hours post-op 6 hours post-op 8 hours post-op 16 hours post-op 24 hours post-op Min 24 hours post-op Kim 1 hour post-op Serratus-intercostal et al.  3 hours post-op plane block and 6 hours post-op intermediate cervical 9 hours post-op plexus block 24 hours post-op versus control Kulhari After administration of Pectoral nerve block et al  block versus thoracic paravertebral block 24 hours post-op 0 hours post-op 0.5 hours post-op 1 hour post-op 2 hours post-op 4 hours post-op 6 hours post-op 8 hours post-op 12 hours post-op 24 hours post-op Moura T0 (after recovering Femoral et al.  consciousness) nerve block 1 hour post-op 2 hours post-op First 2 hours Nagafuchi Exiting operating room Femoral nerve et al.  3 hours post-op block-sciatic nerve 12 hours post-op block versus femoral nerve block-LIA 24 hours post-op Salviz Hours Interscalene brachial et al.  plexus block D1 post-op D2 post-op D3 post-op D4 post-op D5 post-op D6 post-op D7 post-op D1 post-op D2 post-op D3 post-op D4 post-op D5 post-op D6 post-op D7 post-op Sawhney D1 post-op Combined adductor et al.  canal block with periarticular infiltration versus adductor canal nerve block D1 post-op D2 post-op D2 post-op Sato At rest just after surgery Sciatic and femoral et al.  6 hours after surgery continuous versus AM D1 post-op single shot PM D1 post-op AM D2 post-op PM D2 post-op Over first 48 hours Siddiqui Every 5 min first hour Lumbar plexus block et al.  4 hours post-op 8 hours post-op 16 hours post-op 20 hours post-op 24 hours post-op 28 hours post-op 32 hours post-op 36 hours post-op Sindjelic Min Cervical plexus block et al.  24 hours post-op Schoenmakers Min Popliteal continuous et al.  Immediately post-op 24 hours Immediately post-op 24 hours Subramanyam 30 min post-op Supraclavicular et al.  60 min post-op brachial plexus block 90 min post-op Min Baseline before ISB Immediately post-op 6 hours post-op worst pain 8 hours post-op worst pain 10 hours post-op worst pain 12 hours post-op worst pain 14 hours post-op worst pain AM D1 post-op worst pain Stundner Baseline before ISB Interscalene brachial et al.  Immediately post-op plexus block 6 hours post-op worst pain 8 hours post-op worst pain 10 hours post-op worst pain 12 hours post-op worst pain 14 hours post-op worst pain AM D1 post-op worst pain Thybo 4 hours post-op (T4) at T0 et al.  (pts able to move toes but before SAB worn off) T0 Lateral cutaneous femoral nerve block T1 (after T0) T2 (after T0) T4 (after T0) T8 (after T0) T12 (after T0) T24 (after T0) 0-24 hours post-op Wegener At rest at 3 months Sciatic nerve block et al.  On mobilising at 3 months At rest 12 months On mobilising at 12 months At rest 3 months On mobilising at 3 months At rest 12 months On mobilising at 12 months Wegener AM D1 post-op Sciatic and femoral et al.  PM D1 post-op continuous AM D2 post-op versus single PM D2 post-op AM D3 post-op PM D3 post-op AM D1 post-op PM D1 post-op AM D2 post-op PM D2 post-op AM D3 post-op PM D3 post-op D0 post-op D1 post-op D2 post-op D3 post-op Wongyingsinn 24 hours post-op Thoracic et al.  48 hours post-op epidural block 72 hours post-op 24 hours post-op 48 hours post-op 72 hours post-op 24 hours post-op 48 hours post-op 72 hours post-op 30 min post-op 1 hour post-op 2 hours post-op 3 hour post-op 4 hours post-op 24 hours post-op Ya Deau 30 min post-op Lumbar plexus block et al.  1 hour post-op 2 hours post-op 3 hour post-op 4 hours post-op 24 hours post-op Zhai Before block Interscalene brachial et al.  Right before discharge from plexus block PACU 4 hours after block 8 hours after block 24 hours after block 24 hours after block D0 post-op = Day 0 postoperatively; D1 post-op = Day 1 postoperatively; D2 post-op = Day 2 postoperatively; D3 post-op = Day 3 postoperatively; D4 post-op = Day 4 postoperatively; D5 post-op = Day 5 postoperatively; D6 post-op = Day 6 postoperatively; D7 post-op = Day 7 postoperatively; min- = minutes; NRS = numeric (verbal) rating scale (0 = no pain to 10 = worst imaginable pain); VAS = visual analogue scale (0 mm = no pain to 100 mm = worst imaginable pain); APS-POQ-R = American Pain Society Patient Outcome Questionnaire Revised; WOMAC score = Western Ontario and McMaster Universities Osteoarthritis Index (5 pain questions included) OA specific; Oxford Knee Score 12-item knee questionnaire on pain; for measurement tool, "not stated" = whether pain score recorded at rest or on movement not stated in methods. TABLE 2: Summary of pain outcomes reported in included studies. Pain outcome No. of studies Studies utilising outcome VAS 11 Andersen et al. ; Bengisun et al. ; Bharti et al. ; Boussofara et al. ; Capdevilla et al. ; Karthikeyan et al. ; Kim et al. ; Kulhari et al. ; Sato et al. ; Siddiqui et al. ; Wegener et al.  VAS on a 1 Thybo et al.  specified activity Time to VAS 3 1 Andersen et al.  cm NRS at rest 10 Ambrosoli et al. ; Choi et al. ; Fritsch et al. ; Sawhney et al. ; Schoenmakers et al. ; Stundner et al. ; Wegener et al. ; Wongyingsinn et al. ; YaDeau et al. ; Subramanyam et al.  NRS on activity 9 Ambrosoli et al. ; Choi et al. ; Fritsch et al. ; Sawhney et al. ; Schoenmakers et al. ; Stundner et al. ; Wegener et al. ; Wongyingsinn et al. ; YaDeau et al.  Maximum NRS 3 Hamdani et al. ; Salviz et score al. ; Zhai et al.  Average NRS 1 Hamdani et al.  Analgesic 7 Bharti et al. ; Capdevilla et consumption al. ; Kulhari et al. ; Moura et al. ; Nagafuchi et al. ; Salviz et al. ; Sawhney et al.  Opioid 16 Andersen et al. ; Bharti et consumption al. ; Boussofara et al. ; Choi et al. ; Diakomi et al. ; Elkassabany et al. ; Hamdani et al. ; Karthikeyan et al. ; Kulhari et al. ; Moura et al. ; Salviz et al. ; Sawhney et al. ; Sato et al. ; Sindjelic et al. ; Thybo et al. ; Wegener et al.  Time to 1st 2 Salviz et al. ; Zhai et al. pain  Time to 1st 6 Karthikeyan et al. ; Kulhari analgesic et al. ; Moura et al. ; request Schoenmakers et al. ; Sindjelic et al. ; Subramanyam et al.  Time to 1st 1 Diakomi et al.  opioid request Sleep 2 Ambrosoli et al. ; Andersen disturbance et al.  WOMAC 1 Wegener et al.  APS-POQ-R 1 Elkassabany et al.  TABLE 3: Summary of regional techniques investigated in included studies. Blocks studied Number Studies of studies Supraclavicular 2 Subramanyam et al. ; Bharti et al.  Interscalene 5 Bengisun et al. ; Fritsch et al. ; Salviz et al. ; Stundner et al. ; Zhai et al.  Pectoral 1 Kulhari et al.  Serratus-intercostal 1 Kim et al.  Fascia iliaca 1 Diakomi et al.  Femoral 6 Sato et al. ; Wegener et al. ; Choi et al. ; Thybo et al. ; Nagafuchi et al. ; Elkassabany et al.  Sciatic 4 Sato et al. ; Wegener et al. ; Wegener et al. ; Moura et al.  Adductor 1 Sawhney et al.  Saphenous 1 Andersen et al.  Cervical plexus 2 Sindjelic et al. ; Karthikeyan et al.  Lumbar plexus 2 YaDeau et al. ; Siddiqui et al.  Thoracic epidural 1 Wongyingsinn et al.  Spinal 1 Boussofara et al.  Interscalene catheter 3 Hamdani et al. ; Capdevilla et al. ; Fredrickson et al.  Popliteal catheter 2 Capdevilla et al. ; Schoenmakers et al.  Sciatic catheter 1 Ambrosoli et al.  TABLE 4 Rank Impact factor 1 Anesthesiology 5.879 2 Pain 5.213 3 British Journal of Anaesthesia 4.853 4 Pain physician 3.542 5 Anesthesia and Analgesia 3.472 6 Anaesthesia 3.382 7 Regional Anaesthesia and Pain management 3.089 8 Journal of Neurosurgical Anaesthesia 2.99 9 European Journal of Anaesthesia 2.942 10 European Journal of Pain 2.928 11 Canadian Journal of Anesthesia 2.527 12 Clinical Journal of Pain 2.527 13 Pain Practice 2.361 14 Acta Anaesthesia Scandinavia 2.322 15 Minerva Anesthesiology 2.134 16 Journal of Clinical Monitoring and Computing 1.985 17 Current Opinion Anesthesiology 1.979 18 * Pediatric Anesthesia 1.85 19 * International Journal of Obstetric Anesthesia 1.598 20 Journal of Cardiothoracic and Vascular Anaesthesia 1.463 21 BMC Anesthesiology 1.375 22 Anaesthesia and Intensive Care 1.296 * These journals cover obstetric and pediatric anesthesia; hence, they were not used in this study (owing to the inclusion criteria of general adult population).
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|Author:||Pushpanathan, E.; Setty, T.; Carvalho, B.; Sultan, P.|
|Publication:||Anesthesiology Research and Practice|
|Date:||Jan 1, 2018|
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