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Regional Anesthesia Articles of the Year, 2017

Jul 30, 2018, 09:10 AM by Christopher Lam, MD; Priyanka Ghosh, MD; Thomas Cochran, MD; Brian F.S. Allen, MD

The field of regional anesthesia expands and improves thanks to the work of countless investigators who pour tremendous effort into crafting well-designed studies. Knowledge creation races ahead; every year, we have more and more to know. To support the increased pace of regional anesthesia research, in 2018, Regional Anesthesia and Pain Medicine is expanding from six to now eight issues per year. Staying up to date can be a challenge, requiring delving into multiple journals and selecting studies to read based on titles, abstracts, or peer recommendations. To assist your reading, we have conducted an informal survey of all United States and Canadian regional anesthesiology fellowship directors, asking them to identify the most important articles of 2017, excluding editorials.


“The article should serve as an invaluable aid to those designing a total joint protocol or contemplating their institution's current practices.”


None of the four top articles selected describes a novel technique. Rather, they use various methods to help guide care and block selection in common clinical conditions. This theme highlights the lack of agreement in the regional anesthesia literature around what constitutes optimal care or if one therapy can be shown to be superior to others. The methods employed in these articles also vary, including a randomized controlled trial (RCT), a large retrospective database analysis, a scoping review, and a network meta-analysis. Interestingly, the study design choices can result in different conclusions, as illustrated by the two total knee arthroplasty (TKA) studies selected.

Following are brief synopses of the selected top articles of 2017, in no particular order.

Auyong DB, Yuan SC, Choi DS, Pahang JA, Slee AE, Hanson NA. A double-blind randomized comparison of continuous interscalene, supraclavicular, and suprascapular blocks for total shoulder arthroplasty. Reg Anesth
Pain Med 2017;42(3):302–309. https://doi.org/10.1097/AAP.0000000000000578

Auyong et al investigated the respiratory and analgesic effects of three different brachial plexus blocks for shoulder arthroplasty. They conducted a 75-patient RCT of continuous interscalene, supraclavicular, or suprascapular blocks, randomizing in a 1:1:1 ratio with 25 patients per group. The primary outcome was the assessment of vital capacity by spirometry after 24 hours of continuous nerve block infusion at 6 mL/h of 0.2% ropivacaine without an initial bolus. The continuous interscalene and supraclavicular groups had large decreases in vital capacity, with mean decreases of 991 mL and 803 mL, respectively. Differences between the interscalene and supraclavicular groups were not statistically significant. The continuous suprascapular group fared better, with a mean vital capacity reduction of only 464 mL, which was significantly better than either of the other groups. Secondary outcomes studied included diaphragm excursion by ultrasound, pain scores, opioid consumption, and adverse effects. Significantly decreased diaphragmatic excursion was identified in the interscalene group compared with the supraclavicular group (p = .012) and the suprascapular group (p < .001). Pain scores by numeric rating scale (2.2, 1.6, and 2.6) and 24-hour opioid consumption (13.8 mg, 9.9 mg, and 21.8 mg intravenous morphine equivalents) for groups interscalene, supraclavicular, and suprascapular, respectively, were not significantly different. Fewer adverse effects (ie, Horner syndrome, dyspnea, and hoarseness) were noted in the suprascapular group compared with the interscalene group (p = .002). The findings suggested that continuous suprascapular blockade can preserve pulmonary function for shoulder arthroscopy patients better than interscalene or supraclavicular approaches, without increasing pain or opioid use.


“The article should serve as an invaluable aid to those designing a total joint protocol or contemplating their institution's current practices.”


Malekpour M, Hashmi A, Dove J, Torres D, Wild J. Analgesic choice in management of rib fractures. Anesth Analg 2017;124(6):1906–1911. https://doi.org/10.1213/ANE.0000000000002113

Malekpour et al explored the role of epidural analgesia (EA) compared to paravertebral block (PVB) in treating rib fractures via a retrospective review of the National Trauma Data Bank (NTDB). More than a million records were screened, and patients were included based on the presence of an ICD-9 code indicating rib fractures. Patients were excluded for age less than 18 years or the presence of concurrent sternal, tracheal, or laryngeal trauma. A total of 194,766 patient records were selected, of which 1,110 received paravertebral blocks, 1,073 received epidural analgesia, and 192,583 received no interventions. Patients were then propensity matched twice (scoring the probability of receiving a PVB and probability of requiring any procedure) to eliminate potential confounding variables. This allowed two comparisons: (1) epidural versus paravertebral and (2) procedure (EA or PVB) versus nonprocedure. After 1:1 propensity matching, 557 patients in the EA and PVB groups and 1,114 patients in the nonprocedure group remained for analysis. No significant differences between EA and PVB were found regarding in-hospital mortality, length of stay (LOS),
intensive care unit (ICU) admission, ICU LOS, duration of mechanical ventilation, development of pneumonia, or other complications.

In contrast, the nonprocedure group suffered increased mortality compared with patients receiving either EA or PVB (odds ratio = 2.25; 95% confidence interval: 1.14–3.84). However, the procedure group experienced an increase in hospital LOS and more frequent ICU admissions. Study limitations included dependency on accuracy and completeness of data, the inability to evaluate for comorbidities from the procedures themselves, and the potential for selection bias (despite propensity matching) of more severely injured patients because of the characteristics of the hospitals participating in the NTDB.

Terkawi AS, Mavridis D, Sessler DI, et al. Pain management modalities after total knee arthroplasty: a network
meta-analysis of 170 randomized controlled trials. Anesthesiology 2017;126(5):923–937. https://doi.org/10.1097/ALN.0000000000001607

Terkawi et al performed a network meta-analysis of 170 trials of analgesic regimens for TKA to evaluate efficacy and rank the various modalities available to control pain. A network meta-analysis aggregates study data across multiple studies in much the same way as a conventional meta-analysis, but instead of comparing two treatment arms, it seeks to use direct and indirect comparisons between multiple groups to stratify and rank treatments. Terkawi et al made comparisons between neuraxial analgesia, various combinations of peripheral nerve blocks, periarticular local anesthetic infiltration, auricular acupuncture, patient-controlled analgesia, and placebo. Trials included in the analysis spanned 30 years, represented 12,530 patients from 35 countries, and included 17 different treatment modalities. Pain
at rest, pain with movement, opioid consumption, and range of motion in the first 72 hours after operation were used as primary outcome measures. As with other meta-analyses, the included trials varied in quality, risk of bias, patient population, and types of data present, as well as surgical anesthetic technique and adjuvant analgesic medications. The authors sought to rank the 17 identified treatments for each of the four primary outcomes using a surface under the cumulative ranking curve method of analysis to compare interventions against a theoretical optimal regimen. What emerged was a ranking of interventions. Their conclusions suggested that multiple nerve blocks work better than any single nerve block and are superior to neuraxial or periarticular techniques. The combination of femoral and sciatic nerve blocks was rated the best overall option, although that conclusion masks a great deal of nuance.

Kopp SL, Børglum J, Buvanendran A, et al. Anesthesia and analgesia practice pathway options for total knee arthroplasty. Reg Anesth Pain Med 2017;42(6):683–697. https://doi.org/10.1097/AAP.0000000000000673

Kopp et al approached the complexity of literature surrounding analgesic options in TKA by structuring their investigation as a scoping review. This technique focuses more on describing the literature, in this case the breadth of analgesic options available for TKA, rather than providing any quantitative analysis. Although the expert panel that authored this study initially sought to define optimal practice and create a practice pathway, the approach changed when the heterogeneity in clinical practice became apparent. Instead, the authors compiled and evaluated the risks and benefits of currently available treatment options. Different modalities discussed included neuraxial anesthesia, general anesthesia, peripheral nerve blocks, local anesthetic infiltration, wound catheters, and various oral and intravenous analgesics. The TKA protocol goals are detailed. A sample TKA pathway is provided to illustrate integration of preoperative, intraoperative, and postoperative care. The article highlights the advantages of neuraxial over general anesthesia, and decreases in mortality; reduction of pulmonary, renal, and gastrointestinal complications; and improvements of length of stay and cost are discussed. The article should serve as an invaluable aid to those designing a total joint protocol or contemplating their institution's current practices.

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