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.

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.

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.

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.

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.

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.

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.

Finite element modeling of passive material influence on the deformation and force output of skeletal muscle.

The pattern of deformation of different structural components of a muscle-tendon complex when it is activated provides important information about the internal mechanics of the muscle. Recent experimental observations of deformations in contracting muscle have presented inconsistencies with current widely held assumption about muscle behavior. These include negative strain in aponeuroses, non-uniform strain changes in sarcomeres, even of individual muscle fibers and evidence that muscle fiber cross sectional deformations are asymmetrical suggesting a need to readjust current models of contracting muscle. We report here our use of finite element modeling techniques to simulate a simple muscle-tendon complex and investigate the influence of passive intramuscular material properties upon the deformation patterns under isometric and shortening conditions. While phenomenological force-displacement relationships described the muscle fiber properties, the material properties of the passive matrix were varied to simulate a hydrostatic model, compliant and stiff isotropically hyperelastic models and an anisotropic elastic model. The numerical results demonstrate that passive elastic material properties significantly influence the magnitude, heterogeneity and distribution pattern of many measures of deformation in a contracting muscle. Measures included aponeurosis strain, aponeurosis separation, muscle fiber strain and fiber cross-sectional deformation. The force output of our simulations was strongly influenced by passive material properties, changing by as much as ~80% under some conditions. The maximum output was accomplished by introducing anisotropy along axes which were not strained significantly during a muscle length change, suggesting that correct costamere orientation may be a critical factor in the optimal muscle function. Such a model not only fits known physiological data, but also maintains the relatively constant aponeurosis separation observed during in vivo muscle contractions and is easily extrapolated from our plane-strain conditions into a three-dimensional structure. Such modeling approaches have the potential of explaining the reduction of force output consequent to changes in material properties of intramuscular materials arising in the diseased state such as in genetic disorders.

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.

Asymmetric deformation of contracting human gastrocnemius muscle.

Muscle fiber deformation is related to its cellular structure, as well as its architectural arrangement within the musculoskeletal system. While playing an important role in aponeurosis displacement, and efficiency of force transmission to the tendon, such deformation also provides important clues about the underlying mechanical structure of the muscle. We hypothesized that muscle fiber cross section would deform asymmetrically to satisfy the observed constant volume of muscle during a contraction. Velocity-encoded, phase-contrast, and morphological magnetic resonance imaging techniques were used to measure changes in fascicle length, pinnation angle, and aponeurosis separation of the human gastrocnemius muscle during passive and active eccentric ankle joint movements. These parameters were then used to subsequently calculate the in-plane muscle area subtended by the two aponeuroses and fascicles and to calculate the in-plane (dividing area by fascicle length), and through-plane (dividing muscle volume by area) thicknesses. Constant-volume considerations of the whole-muscle geometry require that, as fascicle length increases, the muscle fiber cross-sectional area must decrease in proportion to the length change. Our empirical findings confirm the definition of a constant-volume rule that dictates that changes in the dimension perpendicular to the plane, i.e., through-plane thickness, (-6.0% for passive, -3.3% for eccentric) equate to the reciprocal of the changes in area (6.8% for passive, 3.7% for eccentric) for both exercise paradigms. The asymmetry in fascicle cross-section deformation for both passive and active muscle fibers is established in this study with a ∼22% in-plane and ∼6% through-plane fascicle thickness change. These fiber deformations have functional relevance, not only because they affect the force production of the muscle itself, but also because they affect the characteristics of adjacent muscles by deflecting their line of pull.

Human soleus muscle architecture at different ankle joint angles from magnetic resonance diffusion tensor imaging.

The orientation of muscle fibers influences the physiological cross-sectional area, the relationship between fiber shortening and aponeurosis shear, and the total force produced by the muscle. Such architectural parameters are challenging to determine particularly in vivo in multicompartment structures such as the human soleus with a complex arrangement of muscle fibers. The objective of this study was to map the fiber architecture of the human soleus in vivo at rest in both neutral and plantarflexed ankle positions using an MRI-based method of diffusion tensor imaging (DTI). Six subjects were imaged at 3 Tesla with the foot at rest in the two ankle positions. Eigenvalues, fractional anisotropy (FA), and eigenvector orientations of fibers in the different soleus subcompartments were evaluated after denoising of the diffusion tensor. The fiber architecture from DTI was similar to earlier studies based on a 3D fiber model from cadavers. The three eigenvalues of the diffusion tensor increased by ∼14% on increasing the joint plantarflexion angle in all of the soleus subcompartments, whereas FA showed a trend to decrease in the posterior and marginal soleus and to increase in the anterior soleus. The angle change in the lead eigenvector between the two foot positions was significant: ∼41° for the posterior soleus and ∼48° for the anterior soleus. Fibers tracked from the subcompartments support these changes seen in the eigenvector orientations. DTI-derived, subject-specific, muscle morphological data could potentially be used to model a more complete description of muscle performance and changes from disease.