A practical guide to adopting Bayesian analyses in clinical research.

Background: Bayesian statistical approaches are extensively used in new statistical methods but have not been adopted at the same rate in clinical and translational (C&T) research. The goal of this paper is to accelerate the transition of new methods into practice by improving the C&T researcher's ability to gain confidence in interpreting and implementing Bayesian analyses. Methods: We developed a Bayesian data analysis plan and implemented that plan for a two-arm clinical trial comparing the effectiveness of a new opioid in reducing time to discharge from the post-operative anesthesia unit and nerve block usage in surgery. Through this application, we offer a brief tutorial on Bayesian methods and exhibit how to apply four Bayesian statistical packages from STATA, SAS, and RStan to conduct linear and logistic regression analyses in clinical research. Results: The analysis results in our application were robust to statistical package and consistent across a wide range of prior distributions. STATA was the most approachable package for linear regression but was more limited in the models that could be fitted and easily summarized. SAS and R offered more straightforward documentation and data management for the posteriors. They also offered direct programming of the likelihood making them more easily extendable to complex problems. Conclusion: Bayesian analysis is now accessible to a broad range of data analysts and should be considered in more C&T research analyses. This will allow C&T research teams the ability to adopt and interpret Bayesian methodology in more complex problems where Bayesian approaches are often needed.

Comparing liposomal bupivacaine plus bupivacaine to bupivacaine alone in interscalene blocks for rotator cuff repair surgery: a randomized clinical trial.

BACKGROUND: Single-injection interscalene brachial plexus blocks are used for analgesia for rotator cuff repair (RCR) but have limited duration. The value of adding liposomal bupivacaine (LB) to prolong single-injection interscalene blocks is unclear. The purpose of this trial is to evaluate the addition of LB to regular bupivacaine interscalene blocks for patients undergoing arthroscopic RCR. METHODS: In this prospective, randomized trial, 70 patients undergoing primary RCR with equal group allocation were randomized by random number generator to receive an interscalene block with 20 mL of 0.5% bupivacaine or 10 mL 0.5% bupivacaine plus 133 mg LB. The primary outcome was cumulative opioid consumption within 72 hours of the procedure. Secondary outcomes included maximum pain scores and quality of recovery 15 survey scores. RESULTS: 70 of the 80 randomized patients were included in final analysis following exclusion for protocol violations and loss to follow-up. Cumulative opioid consumption (oral morphine equivalents) within 72 hours in patients receiving LB was a median (IQR) of 31.9 mg (0, 73.1) compared with 45.0 mg (15.0, 108.8) among patients receiving bupivacaine alone (p=0.312). Patients receiving LB demonstrated mixed results regarding worst pain scores with improvements at 24 hours and 72 hours, but not 48 hours. CONCLUSIONS: LB added to bupivacaine interscalene blocks does not reduce opioid consumption within 72 hours following arthroscopic RCR. TRIAL REGISTRATION NUMBER: NCT03587584.

Evaluation of Diaphragmatic Function after Interscalene Block with Liposomal Bupivacaine: A Randomized Controlled Trial.

BACKGROUND: Interscalene blocks provide analgesia for shoulder surgery but also cause phrenic nerve paralysis. Liposomal bupivacaine is approved for use in interscalene blocks with the potential to provide longer pain control. However, the impact of liposomal bupivacaine on the phrenic nerve has not been evaluated. It was hypothesized that patients who received an interscalene block with both bupivacaine and liposomal bupivacaine would have a decreased diaphragmatic excursion when compared to bupivacaine alone at 24 h. METHODS: This was a double-blinded study of adult patients who were randomized to receive an interscalene block with either 20 ml 0.5% bupivacaine (bupivacaine group) or 10 ml 0.5% bupivacaine plus 10 ml liposomal bupivacaine (liposomal bupivacaine group). Twenty-six patients were randomized with 22 included in the analysis. Diaphragmatic excursion (via ultrasound) and spirometry were assessed before the block, in the postanesthesia care unit, and at 24 h postblock. The primary outcome was diaphragm excursion with sigh. No adverse events were observed. RESULTS: At 24 h, the liposomal bupivacaine group median [25th, 75th], had a greater percent change in diaphragmatic excursion during sigh breath compared to the bupivacaine group, -24% [-30, -9] versus 9% [-8, 26], difference in location, 32 (95% CI, 12 to 52), P = 0.007. Five patients in the liposomal bupivacaine group had a greater than 25% reduction in diaphragmatic excursion at 24 h versus zero in the bupivacaine group. They also had a significantly greater percent reduction in forced expiratory volume in 1 s and forced vital capacity compared with the bupivacaine group at 24 h (median decrease of 22% vs. 2%, P = 0.006, and median decrease of 19% vs. 1%, P = 0.049, respectively). CONCLUSIONS: The addition of liposomal bupivacaine to bupivacaine in an interscalene block results in statistically significant reductions in diaphragm excursion and pulmonary function testing 24 h after block placement when compared to bupivacaine alone. This reduction, however, falls within the range of normal diaphragmatic function.

Patient Complications after Interscalene Block: A Retrospective Comparison of Liposomal Bupivacaine to Nonliposomal Bupivacaine.

BACKGROUND: The purpose of this study was to investigate if the addition of liposome bupivacaine (LB) to an interscalene block (ISB) had an effect on the number of patients with surgical- or block-related complications. METHODS: This was a single-center retrospective chart view performed by identifying patients who received an ISB from January 1, 2014, through April 26, 2018, at the University of Minnesota. 1,518 patients were identified who received an ISB (LB = 784, nonliposomal bupivacaine = 734). Patients were divided into two groups those who did receive liposome bupivacaine in their ISB and those who did not receive liposome bupivacaine in their ISB. Medical records were individually reviewed for surgical procedure, block medications, complications related to the block or surgical procedure, phone calls to the healthcare system for issues related to opioids or pain within 3 and within 30 days, readmissions within 30 days, and emergency room visits for complications within 3 and 30 days. RESULTS: There was no significant difference in the number of patients with surgical or anesthetic complications. Only phone calls for pain within 3 days were significantly different. The LB group had 3.2% of patients call compared to 5.6% in the nonliposomal bupivacaine group (aOR = 1.71 (95% CI: 1.04-2.87), p=0.036). We found no significant difference in any of the other secondary outcomes. CONCLUSIONS: The use of LB in an ISB demonstrated no significant difference compared to nonliposomal bupivacaine in numbers of complications, emergency room visits, and readmissions.

The addition of intrathecal morphine to a transversus abdominis plane block with liposome bupivacaine provides more effective analgesia than transversus abdominis plane block with liposome bupivacaine alone: a retrospective study.

OBJECTIVE: The purpose of this study was to determine if the standardization of using liposomal bupivacaine in transversus abdominis plane (LB TAP) blocks eliminated the benefit of intrathecal morphine (ITM) in patients after undergoing a cesarean section. METHODS: This was a retrospective review of 358 patients who underwent cesarean section over an 11-month period. Patients were divided into two groups: those who received only an LB TAP (67 patients) vs those who received an LB TAP and ITM (291 patients). All blocks were placed bilaterally under ultrasound guidance after closure of the surgical incision, and morphine was added to the spinal used for the case. RESULTS: The group that received ITM in addition to the LB TAP received less opioids in the first 24 hours (median 5 range 0-150 mg morphine equivalents [ME] vs 15 range 0-76 mg ME; P<0.001) and less opioids overall (35 mg range 0-450 mg ME vs 47.5 mg range 0-189 mg ME; P=0.041) when compared to the LB TAP block only group. There was no difference between the two groups in opioid use from 24 to 48 hours or 48 to 72 hours. CONCLUSION: Patients who received ITM in addition to an LB TAP block received less opioids in the first 24 hours and overall when compared to those who received an LB TAP alone. This suggests that ITM still plays a role in providing analgesia to patients who have also received an LB TAP block as a part of their multimodal pain regimen for cesarean sections.

Using a Mobile Device "App" and Proximal Remote Sensing Technologies to Assess Soil Cover Fractions on Agricultural Fields.

Quantifying the amount of crop residue left in the field after harvest is a key issue for sustainability. Conventional assessment approaches (e.g., line-transect) are labor intensive, time-consuming and costly. Many proximal remote sensing devices and systems have been developed for agricultural applications such as cover crop and residue mapping. For instance, current mobile devices (smartphones & tablets) are usually equipped with digital cameras and global positioning systems and use applications (apps) for in-field data collection and analysis. In this study, we assess the feasibility and strength of a mobile device app developed to estimate crop residue cover. The performance of this novel technique (from here on referred to as "app" method) was compared against two point counting approaches: an established digital photograph-grid method and a new automated residue counting script developed in MATLAB at the University of Guelph. Both photograph-grid and script methods were used to count residue under 100 grid points. Residue percent cover was estimated using the app, script and photograph-grid methods on 54 vertical digital photographs (images of the ground taken from above at a height of 1.5 m) collected from eighteen fields (9 corn and 9 soybean, 3 samples each) located in southern Ontario. Results showed that residue estimates from the app method were in good agreement with those obtained from both photograph-grid and script methods (R² = 0.86 and 0.84, respectively). This study has found that the app underestimates the residue coverage by -6.3% and -10.8% when compared to the photograph-grid and script methods, respectively. With regards to residue type, soybean has a slightly lower bias than corn (i.e., -5.3% vs. -7.4%). For photos with residue <30%, the app derived residue measurements are within ±5% difference (bias) of both photograph-grid- and script-derived residue measurements. These methods could therefore be used to track the recommended minimum soil residue cover of 30%, implemented to reduce farmland topsoil and nutrient losses that impact water quality. Overall, the app method was found to be a good alternative to the point counting methods, which are more time-consuming.