An Interventional Pain Algorithm for the Treatment of Postmastectomy Pain Syndrome: A Single-Center Retrospective Review.

OBJECTIVE: Breast cancer is the most common female malignancy worldwide. Breast surgery and adjuvant oncological therapies are often required to increase survival. Treatment-related pain may persist and evolve into postmastectomy pain syndrome (PMPS) in a significant subset of breast cancer survivors. In this retrospective investigation, we will present our experience in applying an interventional algorithmic approach to treat PMPS. DESIGN: A retrospective study. SETTING: An academic cancer hospital. SUBJECTS: Adult females with PMPS diagnosis. METHODS: We reviewed 169 records with the diagnosis of PMPS from 2015 to 2019 within our health system. Pre- and post-injection pain scores, relief duration, and medication usage changes were collected. The decision to perform each procedure was based on the anatomic location of the painful area with the corresponding peripheral sensory innervation. Decision-making flow diagrams were created to present our experience in managing PMPS beyond peripheral nerve blocks. RESULTS: Ultrasound-guided peripheral nerve block results (n=350) were analyzed. The mean baseline pain score was 7, compared with the post-treatment mean score of 3 (95% confidence interval: 3.58 to 3.98, P = 0.0001). Among the responders, the mean pain relief duration was 45 days, with a median of 84 days. Opioid medication consumption was reduced by 11% (t = 0.72, P = 0.47). CONCLUSIONS: Ultrasound-guided nerve blocks of this area could be performed safely and effectively after breast surgeries. We also present our proposed algorithm to provide a stepwise application for selecting the appropriate therapies in the management of more complex PMPS.

Evaluation of an Intrathecal Drug Delivery Protocol Leads to Rapid Reduction of Systemic Opioids in the Oncological Population.

Objective: The article that follows is purposed at demonstrating how IT opioid plus bupivacaine achieves sustained acceptable pain relief while simultaneously rapidly reducing oral morphine equivalents (OME). Background: Cancer patients represent a population with significant morbidity, pain, and limited life expectancy. It is, therefore, vital to achieve satisfactory analgesia quickly and safely. To date, there is limited data in the literature that discusses efficacy of combined intrathecal (IT) medication therapy in reducing systemic opioids in the oncological population. Methods: This was a retrospective analysis that reviewed cancer pain patients from day of IT pump implantation through the six-month postoperative time point. A cohort of 50 oncological patients who had intrathecal drug delivery systems (IDDSs) implanted at Memorial Sloan Kettering Cancer Center between 2017 and 2019 were studied. Median OMEs were the primary modality of analysis for this review. Mean visual analogue scale scores were secondarily reviewed. Results: Median OMEs decreased from 503 preoperative to 105 at six months postoperative time point. Median time to discharge was 6.5 days. Unfortunately, due to malignant mortality, 27 patients did not make it to the 6-month postoperative time point. Discussion: IDDSs with opioid plus bupivacaine represent a safe and efficient route toward expeditious pain relief and decreased OMEs in the cancer pain population.

The Use of L2 and L3 Lumbar Sympathetic Blockade for Cancer-Related Pain, an Experience and Recommendation in the Oncologic Population.

OBJECTIVE: The sympathetic nervous system has a recognized role in transmission of pain, and the lumbar sympathetic blockade is intended to provide analgesia. We share our experiences of lumbar sympathetic blockade in the treatment of cancer-related pain. METHODS: We performed a retrospective analysis of patients with cancer-related pain in the back, abdomen, pelvis, or legs treated at Memorial Sloan Kettering Cancer Center between 2000 and 2018 undergoing lumbar sympathetic blockade at L2 or L3. Blocks were accomplished by injection of local anesthetic or local anesthetic with steroid under fluoroscopy. We measured numerical rating scale scores, percent relief, and relief time. The primary end point was defined as "effective" or "ineffective" pain relief. Effective pain relief was defined as ≥30% relief for at least one day. RESULTS: We identified 124 data points of lumbar sympathetic blockade at L2 or L3, of which 57 were with complete data and used for analysis. Peri-injection, 42 data points had active disease whereas 15 were in remission. Lumbar sympathetic blockade was 67% effective in the back pain cohort, 82% effective in the abdominopelvic pain cohort, and 75% effective in the leg pain cohort. Seventeen data points went on to neurolysis, two to neuromodulation, and eight to intrathecal pump implantation. CONCLUSIONS: Lumbar sympathetic blockade is effective for back, abdominopelvic, and leg pain related to cancer and its treatments. Future research should be aimed at refining its role within multimodal pain management.

Metabolic Disorders and Anesthesia.

PURPOSE OF REVIEW: Metabolic disorders encompass a group of inherited inborn errors of metabolism that are uncommonly encountered but can pose challenges when encountered during the perioperative period. Hence, it is paramount that anesthesiologists are experienced and familiar with management of these conditions. RECENT FINDINGS: Hundreds of inborn errors of metabolism have already been identified, yet new metabolic disorders continue to be discovered with advancements in genomic science. SUMMARY: In our general review, we define the more common metabolic disorders encountered in perioperative medicine and discuss the perioperative anesthetic considerations and challenges associated with each disorder. The following disorders are covered in our review: disorders of carbohydrate metabolism, disorders of amino acid metabolism, disorders of branched-chain amino acid metabolism, organic acidemias, mitochondrial disorders, lysosomal storage disorders, metal metabolism disorders, and urea cycle disorders.

PERIOPERATIVE PAIN CONTROL IN GASTROINTESTINAL SURGERY.

Perioperative pain control in the setting of gastrointestinal surgery presents unique challenges for the clinician, including the incidence of ileus and its potential exacerbation by analgesics, large incisions, patient characteristics and a wide variety of other factors. At the same time, optimizing postoperative pain control is of key significance in this patient population and has implications for both medical and surgical outcomes, length of hospital stay and associated costs and risks of developing chronic postsurgical pain. Data from recent clinical trials and other studies have highlighted the impact of specific surgical and anesthetic techniques on post-operative pain for several types of abdominal surgeries, including pancreatoduodenectomy, hepatectomy, gastric bypass, cholecystectomy, colectomy, and appendectomy. The management of pain may be optimized through the multidisciplinary and concerted efforts between clinicians involved in the perioperative care of patients undergoing gastrointestinal surgery.

The invertebrate microtubule-associated protein PTL-1 functions in mechanosensation and development in Caenorhabditis elegans.

PTL-1, a microtubule-associated protein of the structural MAP2/tau family, is the sole member of this gene family in Caenorhabditis elegans. Sequence analysis of available invertebrate genomes revealed a number of single, putative tau-like genes with high similarity to ptl-1. The ptl-1 gene is expressed in a number of cells, most notably mechanosensory neurons. We examined the role of ptl-1 in C. elegans in adult neurons as well as during development. A ptl-1 knockout strain of worms exhibited an egg-hatching defect, as well as a reduced sensitivity to touch stimuli. In addition, the knockout allele ptl-1(ok621) acts as a dominant enhancer of several temperature-sensitive alleles of mec-7 and mec-12, which code the isoforms of beta-tubulin and alpha-tubulin that together form the unusual 15 protofilament microtubules involved in touch sensation. These results demonstrate for the first time a functional role for this microtubule-associated protein in nematodes and suggest that PTL-1 is involved in mechanosensation as well as some aspect of embryogenesis.