A prospective, randomized trial of liposomal bupivacaine compared to conventional bupivacaine on pain control and postoperative opioid use in adults receiving adductor canal blocks for total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is a commonly performed procedure to alleviate pain and improve functional limitations caused by end-stage joint damage. Effective management of postoperative pain following TKA is crucial to the prevention of complications and enhancement of recovery. Adductor canal blocks (ACB) with conventional bupivacaine (CB) provide adequate analgesia after TKA, but carry a risk of rebound pain following block resolution. Liposomal bupivacaine (LB) is an extended-release local anesthetic that can provide up to 72 h of pain relief. The objective of this study was to compare postoperative outcomes between ACBs using LB and CB after TKA. METHODS: This single institution, prospective, randomized, clinical trial enrolled patients scheduled for TKA. Participants were randomized to receive ACB with either LB or CB. Pain scores up to 72 h postoperatively were assessed as the primary outcome. Opioid consumption and length of stay were evaluated as secondary outcomes. RESULTS: A total of 80 patients were enrolled. Demographic and clinical characteristics were similar between the two groups. LB group showed significantly lower cumulative opioid use during the 72 h evaluated (P = 0.016). There were no differences in pain scores or length of stay between the groups. CONCLUSION: The study demonstrated that LB ACBs led to significantly lower opioid consumption in the days following TKA without affecting pain scores or length of stay. This finding has important implications for improving postoperative outcomes and reducing opioid use in TKA patients. Previous studies have reported inconsistent results regarding the benefits of LB, highlighting the need for further research. TRIAL REGISTRATION: This project was retrospectively registered with clinicaltrials.gov ( NCT05635916 ) on 2 December 2022.

Use of machine learning theory to predict the need for femoral nerve block following ACL repair.

OBJECTIVE: We report on a classification approach using machine learning (ML) algorithms for prediction of postoperative femoral nerve block (FNB) requirement following anterior cruciate ligament (ACL) reconstruction. BACKGROUND: FNBs are commonly performed for ACL reconstruction to control postoperative pain. Ideally, anesthesiologists would target preoperative FNB only to ACL reconstruction patients expected to experience severe postoperative pain. Perioperative factors associated with postoperative FNB placement following ACL reconstruction remain unclear, may differ among separate surgical facilities, and render such predictions difficult. METHODS: We conducted a chart review of 349 patients who underwent ACL reconstruction at a single outpatient surgical facility. Standard perioperative data commonly available during routine preoperative examination were recorded. ML classifiers based on logistic regression, BayesNet, multilayer perceptron, support vector machine, and alternating decision tree (ADTree) algorithms were then developed to predict which patients would require postoperative FNB. RESULTS: Each of the ML algorithms outperformed traditional logistic regression using a very limited data set as measured by the area under the receiver operating curve, with ADTree achieving the highest score of 0.7 in the cross-validated sample. Logistic regression outperformed all other classifiers with regard to kappa statistics and percent correctly classified. All models were prone to overfitting in comparisons of training vs cross-validated samples. CONCLUSION: ML classifiers may offer improved predictive capabilities when analyzing medical data sets compared with traditional statistical methodologies in predicting severe postoperative pain requiring peripheral nerve block.

Neurogenic thoracic outlet syndrome: A case report and review of the literature.

Neurogenic thoracic outlet syndrome (NTOS) is an oft-overlooked and obscure cause of shoulder pain, which regularly presents to the office of shoulder surgeons and pain specialist. With this paper we present an otherwise healthy young female patient with typical NTOS. She first received repeated conservative treatments with 60 units of botulinium toxin injected into the anterior scalene muscle at three-month intervals, which providing excellent results of symptom-free periods. Later a trans-axillary first rib resection provided semi-permanent relief. The patient was followed for 10 years after which time the symptoms reappeared. We review the literature and elaborate on the anatomy, sonoanatomy, etiology and characteristics, symptoms, diagnostic criteria and treatment modalities of NTOS. Patients with NTOS often get operated upon - even if just a diagnostic arthroscopy, and an interscalene or other brachial plexus block may be performed. This might put the patient in jeopardy of permanent nerve injury, and the purpose of this review is to minimize or prevent this.