Waddell (Nonorganic) Signs and Their Association With Interventional Treatment Outcomes for Low Back Pain.

BACKGROUND: The rising use of injections to treat low back pain (LBP) has led to efforts to improve selection. Nonorganic (Waddell) signs have been shown to portend treatment failure for surgery and other therapies but have not been studied for minimally invasive interventions. METHODS: We prospectively evaluated the association between Waddell signs and treatment outcome in 3 cohorts: epidural steroid injections (ESI) for leg pain and sacroiliac joint (SIJ) injections and facet interventions for LBP. Categories of Waddell signs included nonanatomic tenderness, pain during sham stimulation, discrepancy in physical examination, overreaction, and regional disturbances divulging from neuroanatomy. The primary outcome was change in patient-reported "average" numerical rating scale for pain intensity (average NRS-PI), modeled as a function of the number of Waddell signs using simple linear regression. Secondary outcomes included a binary indicator of treatment response. We conducted secondary and sensitivity analyses to account for potential confounders. RESULTS: We enrolled 318 patients: 152 in the ESI cohort, 102 in the facet cohort, and 64 in the SIJ cohort, having sufficient data for primary analysis on 308 patients. Among these, 62% (n = 192) had no Waddell signs, 18% (n = 54) had 1 sign, 11% (n = 33) had 2, 5% (n = 16) had 3, 2% (n = 7) had 4, and about 2% (n = 6) had all 5 signs. The mean change in average NRS-PI in each of these 6 groups was -1.6 ± 2.6, -1.1 ± 2.7, -1.5 ± 2.5, -1.6 ± 2.6, -1 ± 1.5, and 0.7 ± 2.1, respectively, and their corresponding treatment failure rates were 54% (102 of 192), 67% (36 of 54), 70% (23 of 33), 75% (12 of 16), 71% (5 of 7), and 83% (5 of 6). In the primary analysis, an increasing number of Waddell signs were not associated with a significant decrease in average NRS-PI (coefficient [Coef] = 0.19; 95% confidence interval [CI], -0.43 to 0.05; P = .12). A higher number of Waddell signs were associated with treatment failure, with a 1.35 increased odds of treatment failure per cumulative number of signs (P = .008). CONCLUSIONS: Whereas this study found no consistent relationship between Waddell signs and decreased mean pain scores, a significant relationship between the number of Waddell signs and treatment failure was observed.

Point-of-Care Ultrasound Aids in the Management of Patient Taking Semaglutide Before Surgery: A Case Report.

Semaglutide, a glucagon-like peptide-1 (GLP-1) analog, has various effects on the gastrointestinal tract. In patients undergoing anesthesia delayed gastric emptying time can have sequelae if not identified preoperatively. Modalities include thorough history regarding the last dose administration of a GLP-1 analog and ultrasound of gastric contents before induction of anesthesia. We present a case in which gastric ultrasound identified a patient at increased risk for aspiration on induction and allowed for appropriate alterations in the anesthetic plan.

Patient selection in ambulatory surgery.

Patient selection is important for ambulatory surgical practices. Proper patient selection for ambulatory practices will optimize resources and lead to increased patient and provider satisfaction. As the number and complexity of procedures in ambulatory surgical centers increase, it is important to ensure that patients are best cared for in facilities that can provide appropriate levels of care. This review addresses the multiple variables and resources that should be considered when selecting patients for anesthesia in ambulatory centers and offices.

Endovascular Plug for Endobronchial Management of an Expectorated Pulmonary Artery Embolization Coil: A Case Report.

Pulmonary artery aneurysms are frequently managed with endovascular embolization. Rare but serious complications of coil embolization are erosion and migration of the coils into the adjacent airways, posing a risk for massive hemoptysis. We report the case of a medically complex patient with a left main pulmonary artery aneurysm treated with coil embolization who ultimately experienced transbronchial migration and expectoration of the coil. We discuss the challenging anesthetic and surgical management of these serious complications, including the use of an endovascular plug to occlude the erosion site and distal airways.

Competency-Based Assessments: Leveraging Artificial Intelligence to Predict Subcompetency Content.

PURPOSE: Faculty feedback on trainees is critical to guiding trainee progress in a competency-based medical education framework. The authors aimed to develop and evaluate a Natural Language Processing (NLP) algorithm that automatically categorizes narrative feedback into corresponding Accreditation Council for Graduate Medical Education Milestone 2.0 subcompetencies. METHOD: Ten academic anesthesiologists analyzed 5,935 narrative evaluations on anesthesiology trainees at 4 graduate medical education (GME) programs between July 1, 2019, and June 30, 2021. Each sentence (n = 25,714) was labeled with the Milestone 2.0 subcompetency that best captured its content or was labeled as demographic or not useful. Inter-rater agreement was assessed by Fleiss' Kappa. The authors trained an NLP model to predict feedback subcompetencies using data from 3 sites and evaluated its performance at a fourth site. Performance metrics included area under the receiver operating characteristic curve (AUC), positive predictive value, sensitivity, F1, and calibration curves. The model was implemented at 1 site in a self-assessment exercise. RESULTS: Fleiss' Kappa for subcompetency agreement was moderate (0.44). Model performance was good for professionalism, interpersonal and communication skills, and practice-based learning and improvement (AUC 0.79, 0.79, and 0.75, respectively). Subcompetencies within medical knowledge and patient care ranged from fair to excellent (AUC 0.66-0.84 and 0.63-0.88, respectively). Performance for systems-based practice was poor (AUC 0.59). Performances for demographic and not useful categories were excellent (AUC 0.87 for both). In approximately 1 minute, the model interpreted several hundred evaluations and produced individual trainee reports with organized feedback to guide a self-assessment exercise. The model was built into a web-based application. CONCLUSIONS: The authors developed an NLP model that recognized the feedback language of anesthesiologists across multiple GME programs. The model was operationalized in a self-assessment exercise. It is a powerful tool which rapidly organizes large amounts of narrative feedback.

Computer-controlled, MR-compatible foot-pedal device to study dynamics of the muscle tendon complex under isometric, concentric, and eccentric contractions.

PURPOSE: To design a computer-controlled, magnetic resonance (MR)-compatible foot pedal device that allows in vivo mapping of changes in morphology and in strain of different musculoskeletal components of the lower leg under passive, isometric, concentric, and eccentric contractions. MATERIALS AND METHODS: A programmable servomotor in the control room pumped hydraulic fluid to rotate a foot-pedal inside the magnet. To validate the performance of the device, six subjects were imaged with gated velocity-encoded phase-contrast (VE-PC) imaging to investigate the dynamics of muscle and aponeurotic structures. RESULTS: Artifact-free VE-PC imaging clearly delineated different muscle compartments by differences in distribution of mechanical strains. High repeatability of contraction cycles allowed establishing that fascicles lengthened 6.1% more during passive compared with eccentric contractions. Aponeurosis separation during passive (range between three locations: -2.6≈1.3 mm) and active (range: -2.4≈1.6 mm) contractions were similar but significantly different from concentric (range: -0.9≈3.3 mm), with proximal and distal regions showing mostly negative values for the first two modes, but positive for the last. CONCLUSION: The device was sufficiently robust and artifact-free to accurately assess, using VE-PC imaging, physiologically important structure and dynamics of the musculotendon complex.

Intraoperative Management of Tracheal Cautery Injury in a Post-Bypass Cardiac Surgery Patient.

We present the case of a tracheal injury that occurred during a Maze procedure performed via sternotomy that was not initially detected by ventilator air leak, but rather by the visual presence of gas bubbles escaping the trachea during chest irrigation. Careful investigation and machine check did reveal a subsequent air leak that would have otherwise been overlooked. Furthermore, the use of intraoperative bronchoscopy was essential in guiding and confirming surgical repair. This case underscores the need for ongoing vigilance and suggests the utility of chest irrigation with Valsalva maneuvers after procedures performed in the vicinity of the trachea to exclude injury.

Maintaining One-Lung Ventilation With an Endobronchial Blocker Through a Damaged Left-Sided Double-Lumen Tube: A Case Report.

One-lung ventilation (OLV) can be accomplished utilizing a double-lumen tube (DLT) and an endobronchial blocker (EBB) or intentionally placing a standard endotracheal tube (ETT) into a mainstem bronchus. However, secondary options must be available should the primary method fail. We present a case where an EBB and a fiberoptic bronchoscope (FOB) were successfully passed through a left-sided DLT to reestablish right-lung isolation after the DLT bronchial cuff was surgically damaged. We advocate competency in placing both DLTs and EBBs, as well as having EBBs readily accessible as a secondary isolation method during OLV.

Fast-Track Cardiac Anesthesia Aids in the Early Diagnosis of Lower Extremity Compartment Syndrome: A Case Report.

A 21-year-old otherwise healthy male with severe asymptomatic mitral regurgitation underwent a mitral valve repair via right thoracotomy and right femoral cannulation for cardiopulmonary bypass. Due to his age and health status, the anesthetic was planned to facilitate early extubation. Immediately on arrival to the intensive care unit, the patient complained of severe right calf pain with decreased sensation of the plantar foot. He was diagnosed with compartment syndrome and was taken back to the operating room for emergent 4-compartment fasciotomy. The fast-track anesthetic allowed for early diagnosis and treatment and prevented a likely catastrophic outcome.

Not Your Average Mediastinal Mass: A Case of a Large Mediastinal Teratoma in a Patient With a History of Polio Disease.

Mediastinal masses can be challenging to the surgical team and anesthetic considerations vary according to the location, pathology, surgical approach, and patient comorbidities. We report the case of a 21 cm symptomatic intrathoracic teratoma in a postpartum patient with a history of poliomyelitis. Significant challenges were presented for anesthetic induction, potential extracorporeal membrane oxygenation, and the use of neuraxial pain techniques and neuromuscular blockade. This case report demonstrates techniques to safely manage a patient with a large symptomatic mediastinal mass and potential neuromuscular disease.

Postoperative Thyroid Storm After Evacuation of a Complete Hydatidiform Mole: A Case Report.

Gestational trophoblastic disease can lead to excess thyroid hormone release and rarely, thyroid storm. We present a case of complete molar pregnancy with hyperthyroidism that was not identified or treated before surgical evacuation of uterine contents. Untreated hyperthyroidism preoperatively led to unanticipated thyroid storm immediately after emergence from anesthesia. It is important for anesthesia providers to recognize the link between gestational trophoblastic disease and thyrotoxicosis, and appreciate the severe consequences than can occur if left untreated. Anesthesia providers should strongly consider preoperative consultation and treatment. Being prepared to treat intraoperative symptoms and thyroid storm is paramount.

Practice Variation in Regional Anesthesia Utilization by Current and Former U.S. Military Anesthesiology Residents.

INTRODUCTION: Per Joint Trauma System guidelines, military anesthesiologists are expected to be ready to lead an Acute Pain Service with regional anesthesia in combat casualty care. However, regional anesthesia practice volume has not been assessed in the military. The objective of this study was to assess regional anesthesia utilization among current residents and graduates of U.S. military anesthesiology residency programs. MATERIALS AND METHODS: All current and former active duty military anesthesiology program residents, trained at any of the four military anesthesiology residency programs between 2013 and 2019, were anonymously surveyed about their regional anesthesia practice. Bivariate statistics described the total single-injection and catheter block techniques utilized in the last month. Cluster analysis assessed for the presence of distinct practice groups within the sample. Follow-up analyses explored potential associations between cluster membership and other variables (e.g., residency training site, residency graduation year, overall confidence in performing regional anesthesia, etc.). This protocol received exemption determination separately from each site's institutional review board. RESULTS: Current and former residents reported broad variation in regional anesthesia practice and clustered into four distinct practice groups. Less than half of respondents utilized a moderate to high number of different single-injection and catheter blocks. CONCLUSIONS: These findings highlight the need for creative solutions to increase regional anesthesia training in military anesthesiology programs and continued ability to implement skills, such that all military anesthesiologists have adequate practice for deployed responsibilities.

Phase-contrast MRI reveals mechanical behavior of superficial and deep aponeuroses in human medial gastrocnemius during isometric contraction.

The behavior of the entire medial gastrocnemius (MG) superficial and deep aponeurosis structure was investigated with velocity-encoded phase-contrast, spin-tag, and three-dimensional morphometric magnetic resonance imaging. The displacements and strain of both these aponeuroses, muscle length, and the cross-sectional segment length of the deep aponeurosis were measured during isometric plantarflexion at 20% and 40% of maximal voluntary contraction (MVC). The length of the entire MG shortened during 20% and 40% MVC. All regions of interest in both aponeuroses moved proximally. Positive strain (lengthening) occurred in both ends of the deep aponeurosis and in the proximal region of the superficial aponeurosis. In contrast, negative strain (shortening) was observed in the middle region of the deep aponeurosis and in the distal region of the superficial aponeurosis. Consistent with this shortening of the deep aponeurosis length along the proximal-distal axis was expansion of the aponeuroses in the medial-lateral and anterior-posterior directions in the cross-sectional plane. It is concluded that at low to moderate force levels of isometric contraction, regional differences in strain occur along the proximal-distal axis of both aponeuroses, and some regions of both aponeuroses shorten.

Effect of chronic unloading and rehabilitation on human Achilles tendon properties: a velocity-encoded phase-contrast MRI study.

The objective of this study was to measure and monitor changes in Achilles tendon mechanical properties and force production capability of triceps surae muscles after 4 wk of limb suspension and 6 wk of physical rehabilitation. Five healthy volunteers underwent unilateral lower limb suspension followed by weekly physiotherapy. A velocity-encoded, phase-contrast magnetic resonance imaging (VE-PC-MRI) technique was used to estimate the tendon strain as a function of force produced during the submaximal isometric contractions. After limb suspension, triceps surae muscle strength decreased to 53.2 +/- 15.6% (mean +/- SD) of the presuspension level (P < 0.05). Young's modulus, estimated from the slope of the tendon stress-strain relationship, decreased by 17.1% (from 140.50 +/- 29.33 to 119.95 +/- 36.07 MPa, P < 0.05), while the tendon transition point, reflecting the "toe region," increased by 55.7% (from 2.2 +/- 1.0% to 3.4 +/- 1.24%). Muscle strength, tendon stiffness, and transition point recovered to presuspension levels by the end of 6 wk of rehabilitation. Calcaneus movement was significant during the "isometric" contraction, accounting for 52.13 +/- 7.63% of the tendon displacement. Tendon cross-sectional area determined from anatomic magnetic resonance axial images remained unchanged, suggesting that the altered tendon elastic modulus and transition point were largely due to material deterioration. The increase in the transition point following chronic unloading as measured by the VE-PC-MRI technique has not been previously reported and offers new insights into the biomechanical changes that may occur in the tendon crimp structure.

Soleus aponeurosis strain distribution following chronic unloading in humans: an in vivo MR phase-contrast study.

The in vivo strain properties of human skeletal muscle-tendon complexes are poorly understood, particularly following chronic periods of reduced load bearing. We studied eight healthy volunteers who underwent 4 wk of unilateral lower limb suspension (ULLS) to induce chronic unloading. Before and after the ULLS, maximum isometric ankle plantar flexion torque was determined by using a magnetic resonance (MR)-compatible dynamometry. Volumes of the triceps surae muscles and strain distribution of the soleus aponeurosis and the Achilles tendon at a constant submaximal plantar flexion (20% pre-maximal voluntary contraction) were measured by using MRI and velocity-encoded, phase-contrast MRI techniques. Following ULLS, volumes of the soleus and the medial gastrocnemius and the maximum isometric ankle plantar flexion (maximum voluntary contraction) decreased by 5.5+/-1.9, 7.5+/-2.7, and 48.1+/-6.1%, respectively. The strain of the aponeurosis along the length of the muscle before the ULLS was 0.3+/-0.3%, ranging from -1.5 to 2.7% in different locations of the aponeurosis. Following ULLS, the mean strain was -6.4+/-0.3%, ranging from -1.6 to 1.3%. The strain distribution of the midregion of the aponeurosis was significantly influenced by the ULLS, whereas the more distal component showed no consistent changes. Achilles tendon strain was not affected by the ULLS. These results raise the issue as to whether these changes in strain distribution affect the functional properties of the triceps surae and whether the probability of strain injuries within the triceps surae increases following chronic unloading in those regions of this muscle complex in which unusual strains occur.

Influence of structure on the tissue dynamics of the human soleus muscle observed in MRI studies during isometric contractions.

This article investigates how the internal structure of muscle and its relationship with tendon and even skeletal structures influence the translation of muscle fiber contractions into movement of a limb. Reconstructions of the anatomy of the human soleus muscle from the Visible Human Dataset (available from the National Library of Medicine), magnetic resonance images (MRI), and cadaver studies revealed a complex 3D connective tissue structure populated with pennate muscle fibers. The posterior aponeurosis and the median septum of the soleus form the insertion of the muscle and are continuous with the Achilles tendon. The distal extremities of the pennate muscle fibers attach to these structures. The anterior aponeurosis is located intramuscularly, between the posterior aponeurosis and the median septum. It forms the origin of the muscle and contacts the proximal extremities of the soleus muscle fibers. MRI measurements of in vivo tissue velocities during isometric contractions (20% and 40% maximum voluntary contractions) revealed a similarly complex 3D distribution of tissue movements. The distribution of velocities was similar to the distribution of major connective tissue structures within the muscle. During an isometric contraction, muscle fiber contractions move the median septum and posterior aponeurosis proximally, relative to the anterior aponeurosis. The pennate arrangement of muscle fibers probably amplifies muscle fiber length changes but not sufficiently to account for the twofold difference in muscle fiber length changes relative to excursion of the calcaneus. The discrepancy may be accounted for by an additional gain mechanism operating directly on the Achilles tendon by constraining the posterior movement of the tendon, which would otherwise occur due to the increasingly posterior location of the calcaneus in plantarflexeion.

Muscle synergism during isometric plantarflexion in achilles tendon rupture patients and in normal subjects revealed by velocity-encoded cine phase-contrast MRI.

BACKGROUND: The triceps surae muscle is often considered to be the sole contributor to the plantarflexion torque although the deeper plantarflexor muscles may also be activated in the plantarflexion task. METHODS: We measured coordinative strategies and muscle synergism during isometric plantarflexion task from 11 volunteers. Velocities from the distal end of the medial gastrocnemius, soleus, and flexor hallucis longus muscles were encoded in the superior-inferior direction using cine phase-contrast magnetic resonance imaging. Eight of the subjects were healthy and served as controls for subject to subject variability. Three of the subjects had experienced an Achilles tendon rupture followed by surgical repair and they were measured up to 8 weeks of rehabilitation. RESULTS: There were marked individual differences in the use of the different muscles during plantarflexion task in control subjects. Soleus to flexor hallucis longus displacement ratio during contraction varied from 0.4 to 9.6 while the moment arm ratio between Achilles tendon and flexor hallucis longus tendons was 1.9 (standard deviation 0.2). In Achilles tendon rupture patients the relative contribution of flexor hallucis longus was very high both in their injured and uninjured leg. This coordinative strategy remained throughout rehabilitation. INTERPRETATION: The findings suggest that early recovery of plantarflexion torque after Achilles tendon rupture may be due to compensation by flexor hallucis longus as well as to normalization of the triceps surae muscle function. Also, this study suggests that the individual differences in coordinative strategies in addition to moment arms and muscle-tendon properties can influence the calculation of forces produced by individual muscles.