Anterior spinal cord syndrome from a spinal epidural hematoma following removal of an epidural catheter.

PURPOSE: Spinal epidural hematoma (SEH) is a rare yet significant complication associated with neuraxial anesthesia. Here, we present the case of a 74-yr-old male who underwent open repair of an abdominal aortic aneurysm. Following the removal of an epidural catheter, the patient developed anterior spinal cord syndrome due to an SEH despite having a normal coagulation profile. CLINICAL FEATURES: This patient's neurologic presentation was marked by a loss of motor function while maintaining fine touch sensation distal to the spinal cord injury. Initial truncal computed tomography (CT) angiography failed to detect vascular compromise or diagnose the SEH. Subsequently, delayed magnetic resonance imaging (MRI) revealed a multilevel thoracic epidural hematoma, spinal cord infarction, and ischemia. Immediate surgical decompression was performed, but unfortunately, the patient had a poor outcome. CONCLUSION: Anterior spinal cord syndrome (ASCS) represents an uncommon neurologic manifestation of SEH, which is typically characterized by a triad of back pain and sensory and motor deficits. Although the initial CT scan was necessary to diagnose the postvascular surgery complication, it did not immediately detect the SEH. In cases of ASCS subsequent to thoracic epidural placement and removal, MRI is the preferred imaging modality for precise diagnosis and assessment of the need for surgical intervention. Despite adherence to anticoagulation guidelines, patients undergoing neuraxial anesthesia may face an elevated risk of developing SEH. Health care professionals should remain vigilant in monitoring for neurologic abnormalities following epidural catheter insertion or removal, particularly in the context of vascular surgery.

RéSUMé: OBJECTIF: L'hématome péridural rachidien est une complication rare mais importante associée à l'anesthésie neuraxiale. Nous présentons ici le cas d'un homme de 74 ans qui a bénéficié d'une réparation ouverte d'un anévrisme de l'aorte abdominale. Après le retrait d'un cathéter péridural, le patient a développé un syndrome médullaire antérieur dû à un hématome péridural rachidien malgré un profil de coagulation normal. CARACTéRISTIQUES CLINIQUES: La présentation neurologique de ce patient était marquée par une perte de la fonction motrice tout en conservant une sensation de toucher fine distale à la lésion médullaire. L'angiographie initiale par tomodensitométrie (TDM) n'a pas permis de détecter d'atteinte vasculaire ni de diagnostiquer un hématome péridural rachidien. Par la suite, une imagerie par résonance magnétique (IRM) retardée a révélé un hématome péridural thoracique à plusieurs niveaux, un infarctus médullaire et une ischémie. Une décompression chirurgicale immédiate a été réalisée, mais malheureusement, l'issue a été mauvaise pour le patient. CONCLUSION: Le syndrome médullaire antérieur représente une manifestation neurologique peu fréquente de l'hématome péridural rachidien, qui se caractérise généralement par une triade de maux de dos et de déficits sensoriels et moteurs. Bien que la tomodensitométrie initiale ait été nécessaire pour diagnostiquer la complication chirurgicale post-vasculaire, elle n'a pas immédiatement détecté l'hématome péridural rachidien. Dans les cas de syndromes médullaires antérieurs consécutifs à la pose et au retrait d'un cathéter péridural thoracique, l'IRM est la modalité d'imagerie privilégiée pour un diagnostic précis et une évaluation de la nécessité d'une intervention chirurgicale. Malgré le respect des directives d'anticoagulation, les patient·es bénéficiant d'une anesthésie neuraxiale peuvent faire face à un risque élevé de développer un hématome péridural rachidien. Les professionnel·les de la santé doivent demeurer vigilant·es dans le monitorage des anomalies neurologiques à la suite de l'insertion ou du retrait d'un cathéter péridural, en particulier dans le contexte d'une chirurgie vasculaire.

Characterization of mononeuropathy of the lateral cutaneous nerve of the calf.

INTRODUCTION/AIMS: Isolated injuries to the lateral cutaneous nerve of the calf (LCNC) branch of the common peroneal nerve can cause obscure chronic posterolateral knee and upper calf pain and sensory symptoms. Routine examination and electrodiagnostic testing do not detect them because the LCNC has no motor distribution and it is not interrogated by the typical peroneal nerve conduction study. There are only about 10 prior cases, thus scant physician awareness, so most LCNC injuries remain misdiagnosed or undiagnosed, hindering care. METHODS: We extracted pertinent records from seven patients with unexplained posterolateral knee/calf pain, six labeled as complex regional pain syndrome, to investigate for mononeuropathies. Patients were asked to outline their skin area with abnormal responses to pin self-examination independently. Three underwent an LCNC-specific electrodiagnostic study, and two had skin-biopsy epidermal innervation measured. Cadaver dissection of the posterior knee nerves helped identify potential entrapment sites. RESULTS: Initiating events included knee surgery (three), bracing (one), extensive kneeling (one), and other knee trauma. All pin-outlines included the published LCNC neurotome. One oftwo LCNC-specific electrodiagnostic studies revealed unilaterally absent potentials. Longitudinal, controlled skin biopsies documented profound LCNC-neurotome denervation then re-innervation contemporaneous with symptom recovery. Cadaver dissection identified the LCNC traversing through the dense fascia of the proximolateral gastrocnemius muscle insertion. DISCUSSION: Isolated LCNC mononeuropathy can cause unexplained posterolateral knee/calf pain syndromes. This series characterizes presentations and supports patient pin-mappings as a sensitive, globally available, low-cost diagnostic aid. Improved recognition may facilitate more rapid, accurate diagnosis and, thus, optimize management and improve outcomes.

High-Frequency Heart Rate Variability Index: A Prospective, Observational Trial Assessing Utility as a Marker for the Balance Between Analgesia and Nociception Under General Anesthesia.

BACKGROUND: Maintaining a balance between nociception and analgesia perioperatively reduces morbidity and improves outcomes. Current intraoperative analgesic strategies are based on subjective and nonspecific parameters. The high-frequency heart rate (HR) variability index is purported to assess the balance between nociception and analgesia in patients under general anesthesia. This prospective observational study investigated whether intraoperative changes in the high-frequency HR variability index correlate with clinically relevant nociceptive stimulation and the addition of analgesics. METHODS: Instantaneous and mean high-frequency HR variability indexes were measured continuously in 79 adult subjects undergoing general anesthesia for laparoscopic cholecystectomy. The indexes were compared just before and 2 minutes after direct laryngoscopy, orogastric tube placement, first skin incision, and abdominal insufflation and just before and 6 minutes after the administration of IV hydromorphone. RESULTS: Data from 65 subjects were included in the final analysis. The instantaneous index decreased after skin incision ([SEM], 58.7 [2.0] vs 47.5 [2.0]; P < .001) and abdominal insufflation (54.0 [2.0] vs 46.3 [2.0]; P = .002). There was no change in the instantaneous index after laryngoscopy (47.2 [2.2] vs 40.3 [2.3]; P = .026) and orogastric tube placement (49.8 [2.3] vs 45.4 [2.0]; P = .109). The instantaneous index increased after hydromorphone administration (58.2 [1.9] vs 64.8 [1.8]; P = .003). CONCLUSIONS: In adult subjects under general anesthesia for laparoscopic cholecystectomy, changes in the high-frequency HR variability index reflect alterations in the balance between nociception and analgesia. This index might be used intraoperatively to titrate analgesia for individual patients. Further testing is necessary to determine whether the intraoperative use of the index affects patient outcomes.

Effects of fresh gas flow, tidal volume, and charcoal filters on the washout of sevoflurane from the Datex Ohmeda (GE) Aisys, Aestiva/5, and Excel 210 SE Anesthesia Workstations.

PURPOSE: We investigated the effects of tidal volume (VT), fresh gas flow (FGF), and a charcoal filter in the inspiratory limb on the washout of sevoflurane from the following Datex Ohmeda (GE) Anesthesia Workstations (AWSs): Aisys, Aestiva/5, and Excel 210SE. METHODS: After equilibrating the AWSs with 2% sevoflurane, the anesthetic was discontinued, and the absorbent anesthesia breathing circuit (ABC), reservoir bag, and test lung were changed. The lung was ventilated with 350 or 200 mL·breath(-1), 15 breaths·min(-1), and a FGF of 10 L·min(-1) while the washout of sevoflurane was performed in triplicate using a calibrated Datex Ohmeda Capnomac Ultima™ and a calibrated MIRAN SapphIRe XL ambient air analyzer until the concentration was ≤ 10 parts per million (ppm). The effects of decreasing the FGF to 5 and 2 L·min(-1) after the initial washout and of a charcoal filter in the ABC were recorded separately. RESULTS: The median washout times with the Aisys AWS (14 min, P < 0.01) and the Aestiva/5 (17 min, P < 0.001) with VT 350 mL·breath(-1) were significantly less than that with the Excel 210SE (32 min). The mean (95% confidence interval) washout time with the Aisys increased to 23.5 (21.5 to 25.5) min with VT 200 mL·breath(-1) (P < 0.01). Decreasing the FGF from 10 to 5 and 2 L·min(-1) with the Aisys caused a rebound in sevoflurane concentration to ≥ 50 ppm. Placement of a charcoal filter in the inspiratory limb reduced the sevoflurane concentration to < 2 ppm in the Aisys and Aestiva/5 AWSs within two minutes. CONCLUSION: The GE AWSs should be purged with large FGFs and VTs ~350 mL·breath(-1) for ~25 min to achieve 10 ppm sevoflurane. The FGF should be maintained to avoid a rebound in anesthetic concentration. Charcoal filters rapidly decrease the anesthetic concentration to < 2 ppm.

The Analgesic Effects of the Thoracic Paravertebral Block on Post-percutaneous Nephrolithotripsy: A Retrospective Study.

INTRODUCTION: Percutaneous nephrolithotripsy (PCNL) is a minimally invasive procedure for treating large and complex kidney stones, often resulting in significant post-operative pain and increased opioid use. This study aims to compare pain scores between patients undergoing PCNL who did and did not receive a preoperative single-shot thoracic paravertebral block (PVB) at the post-anesthesia care unit (PACU) as the primary outcome. Secondary outcomes were patient-controlled analgesia (PCA) usage on post-operative day 1 (POD 1), total opioid consumption on PACU and POD 1, and post-operative nausea and vomiting (PONV). METHODS: A retrospective cohort study was conducted on the medical records of 341 patients who underwent PCNL from July 2014 to April 2016 in a single major academic center. PVB was administered at thoracic levels T7-9 using a volume of 20 cc of bupivacaine, ranging from 0.25% to 0.5%, to achieve the desired analgesic effect. RESULTS: After excluding 34 patients, the study included 123 in the no block (NB) group and 149 in the regional anesthesia (RA) group. There were no differences in demographics, including age, sex, weight and height, BMI, and indication for PCNL. The results revealed that the RA group experienced a statistically significant reduction in PCA usage in both crude and adjusted models (adjusted logistic regression analysis: OR = 0.19, 95% CI = 0.05-0.60; p = 0.008). However, there were no significant changes in total opioid consumption, pain scores, or incidents of PONV. CONCLUSION: The retrospective analysis did not reveal any discernible advantage in pain management associated with the use of PVB for post-PCNL analgesia, except for reducing the percentage of PCA narcotics used. Future investigations with larger sample sizes and meticulous control for surgical indications and complexity are imperative to accurately assess the efficacy of this block in the context of post-PCNL surgery.

Determination of optimal tip position of peripherally inserted central catheters using electrocardiography: a retrospective study.

BACKGROUND: Accurate tip positioning of a peripherally inserted central catheter (PICC) is crucial for optimal drug delivery and avoiding complications. The objective of this study was to evaluate the amplitude ratios of intravascular electrocardiography (ivECG) and external electrocardiography (exECG) according to the tip location. METHODS: This retrospective study analyzed ivECG, exECG, and chest X-ray (CXR) of 278 patients who underwent a PICC procedure. The tip-to-carina distance (TCD) was measured using vertebral body units (VBU) on CXR. Tip locations were categorized as follows: Zone 1, malposition (TCD < 0.8 VBU); Zone 2, suboptimal (0.8 VBU ≤ TCD < 1.5 VBU); Zone 3, optimal (1.5 VBU ≤ TCD ≤ 2.4 VBU); Zone 4, deep (TCD > 2.4 VBU). The amplitude ratios between ivECG and exECG and within ivECG were compared in each zone. RESULTS: The ivECG/exECG amplitude ratios of P-wave (Piv/Pex) and QRS-complex (QRiv/QRex and RSiv/RSex) in Zone 3 were significantly higher than in Zones 1 and 2 (adjusted P < 0.05). The ivECG amplitude ratios of the P-wave and QRS-complex (Piv/QRiv and Piv/RSiv) were significantly lower in Zone 3 than in Zones 1 and 2 (adjusted P < 0.001). The calculated TCD using stepwise multiple regression analysis was estimated to be 1.121 + 0.078 × Piv/Pex - 0.172 × Piv/QRiv. CONCLUSIONS: Though caution is required, amplitude ratios such as Piv/Pex and Piv/QRiv can help determine tip location during the PICC catheterization procedure.

Intraoperative Ultrasound-Guided Transversus Abdominis Plane Catheters Placed for Post-operative Analgesia Following Pedicled Transverse Rectus Abdominis Myocutaneous Flap Breast Reconstruction: A Case Report.

Transverse rectus abdominis (TRAM) flap reconstruction of the breast is a procedure in which a flap of skin, fat, and underlying rectus abdominis muscle is used to reconstruct the breast. This procedure is commonly performed after mastectomy and results in significant pain at the donor abdominal site. We present this case of a 50-year-old female undergoing pedicled TRAM flap surgery in which ultrasound-guided transversus abdominis plane (TAP) catheters were placed intraoperatively, in a novel fashion: under ultrasound guidance, directly on the abdominal musculature, without overlying fat, subcutaneous tissue, or dressing. Our case-reported numeric pain scores ranged from 0-5/10 during postoperative days one to two. The patient's IV morphine requirement on postoperative days zero to two ranged between 1.34 mg to 2.6 mg per day, representing a significant decrease compared to literature-reported opioid consumption after such surgery. Her pain and opioid consumption increased significantly after catheter removal, suggesting the efficacy of our intraoperative TAP catheters.

Unilateral Right-Sided Ultrasound-Guided Erector Spinae Plane Block for Post-Laparoscopic Cholecystectomy Analgesia: A Randomized Control Trial.

Background: Post-laparoscopic cholecystectomy (LC) pain control is still an issue postoperatively. Objectives: We investigated the effectiveness of the unilateral right-side ultrasound-guided erector spinae plane block (ESPB) on post-LC pain intensity and opioid consumption. Methods: This is a parallel-arm randomized control trial on 62 adult patients with an American Society of Anesthesiologists (ASA) physical status ≤ 2 who underwent LC. The patients were randomized into 2 groups (the block group [BG] and the control group [CG]; n = 31 per group). BG received a single-shot right-sided T7 ESPB with 20 mL of 0.2% ropivacaine at arrival time in the post-anesthesia care unit (PACU). CG) received no regional anesthesia. Both groups received patient-controlled intravenous fentanyl and rescue meperidine for analgesia. The primary outcome was the pain intensity determined using a Numerical Rating Scale (NRS) in the first 24 hours after surgery. Secondary outcomes included total fentanyl and meperidine consumption within 24 hours. Results: Median pain scores were significantly higher in CG at rest and with coughing up to 12 hours after surgery compared with BG. Pain scores were higher in CG with a cough at 24 hours compared with BG (median 1 [interquartile range (IQR) 1, 2] vs. 1 [1, 0]; P = 0.0005). Total fentanyl consumption and meperidine consumption within 24 hours were significantly lower in BG compared with CG (median 60 µg [IQR 60, 90] vs 250 µg [90, 300]; P < 0.0001 and median 20 µg [IQR 10, 20] vs 25 [20, 25]; P = 0.002, respectively). Conclusions: A single-shot, right-sided, unilateral ESPB decreases post-LC opioid consumption and pain.

Placement of a Peripherally Inserted Central Catheter in a Prone Patient With COVID-19: Feasibility and Case Report.

The emergence of the coronavirus disease 2019 (COVID-19) virus has increased in patients with acute respiratory distress syndrome (ARDS). The use of prone positioning during COVID-19-associated ARDS has led to improved oxygenation and decreased mortality. Extended hours of proning may delay or prevent traditional approaches to central vascular access, such as jugular, subclavian, or femoral cannulation. A peripherally inserted central catheter (PICC) is a viable option for prone patients. This article presents a PICC placement in a 56-year-old man with COVID-19 ARDS who required 20- to 24-hour prone positioning during his care in the intensive care unit. Insertion of a PICC while the patient is prone expedites lifesaving medications and infusions without waiting for the patient to be stable enough to be turned to the supine position.

The Role of Integrative Educational Intervention Package (Monthly ITE, Mentoring, Mocked OSCE) in Improving Successfulness for Anesthesiology Residents in the National Board Exam.

BACKGROUND: National Board of Anesthesiology (NBA) pass rate is an important and critical step in clinical residency programs. OBJECTIVES: This study was designed to assess the relationship between an integrative educational intervention (IEI) and the relative annual pass rate (RAPR). RAPR is defined as ratio of NBA pass rate of Shahid Beheshti University of Medical Sciences (SBMU) to the NBA pass rate of all the anesthesiology residency programs across Iran. METHODS: In a descriptive-analytic retrospective study from 2012 to 2019, RAPR was calculated. IEI was implanted in the latter 4years period of this time interval includes: (1) individualized mentorship for residents by faculty members; (2) monthly in-training examination (ITE) in written; and (3) periodical mocked OSCE exam. Spearman's correlation coefficient was used to assess correlation between integrative educational intervention and RAPR results. P value less than 0.05 was considered statistically significant. RESULTS: There was a statistically significant relationship between "integrative educational intervention program" and the RAPR results: Spearman's correlation coefficient = 0.655 (P value = 0.039). CONCLUSIONS: The IEI package of Anesthesiology Department, SBMU showed a significant relationship with improvements in successfulness for anesthesiology residents in the National Board Exam (RAPR trend). More prolonged studies could prevail further aspects of these interventions.

Attitudes of Anesthesiology Residents Toward a Small Group Blended Learning Class.

BACKGROUND: Accreditation Council for Graduate Medical Education (ACGME) has been used to evaluate the residents' competency; however, the thriving of residents needs especial training methods and techniques. Small group learning has been used for this propose. OBJECTIVES: This study assessed the attitudes of CA-1 to CA-3 anesthesiology residents toward level-specific small-group blended learning. METHODS: Anesthesiology residents from Department of Anesthesiology, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran participated in this cross-sectional attitude assessment descriptive-analytical study throughout the 2nd academic semester (May-October 2019). They took part in a level-specific small-group blended learning program and filled out an attitude assessment questionnaire. The questionnaire included eight closed questions and was filled out anonymously. RESULTS: The residents believed that this program made important contributions to their theory training and clinical skills of anesthesia; while created a greater sense of solidarity. In addition, nearly the majority of the respondents did not believe that participating in the classes made interference in their clinical duties or was a difficult task. Instead, the majority of residents believed that these classes were in favor of reducing their burnout. The reliability of the questionnaire based on Cronbach's Alpha was 0.885. CONCLUSIONS: Anesthesiology residents are in favor of small-group learning, especially when considering their clinical setting and the degree of burnout they tolerate.

Intraoperative Placement of Paravertebral Catheters to Manage Postoperative Pain in Opioid-Dependent Patients After Thoracolumbar Spine Fusion Surgery: A Case Report.

We introduce a regional technique that involves the intraoperative placement of bilateral paravertebral catheters under direct visualization. The patient had stage IV lung cancer and was on chronic oxycodone therapy. He presented with a T10 metastatic lesion, and underwent spinal decompression with T7-L1 fusion and T10 corpectomy. Before fascial closure, catheters were advanced into the T10 paravertebral space under direct visualization by the surgeon bilaterally. Postoperatively, his pain was well controlled, and narcotic requirements were decreased. Our case report demonstrates that for patients undergoing posterior spine surgery, intraoperative placement of bilateral paravertebral catheters can be used to help manage postoperative pain.

Is a Retrolaminar Approach to the Thoracic Paravertebral Space Possible?: A Human Cadaveric Study.

BACKGROUND AND OBJECTIVES: The retrolaminar block (RB) is used for truncal analgesia, but its mechanism of neural blockade remains obscure. We sought to learn the pattern of local anesthetic spread after thoracic RB using cadaveric models. METHODS: In 8 fresh cadavers, an ultrasound-guided T4 RB was performed with 20 mL of methylene blue 1% and bupivacaine 0.5%. For comparison, an RB at T9 in 1 cadaver and a T4 thoracic paravertebral block in another cadaver were performed. Subsequently, posterior and anterior thoracic dissections were performed to examination where the dye spread. RESULTS: After T4 RB, dye was noted to spread in the ipsilateral retrolaminar plane (all 8 cadavers, median cephalad spread 3.5 cm, caudad spread 10.7 cm, lateral spread 2.5 cm), the contralateral retrolaminar plane (6 cadavers), the paravertebral space (5 cadavers, median of 3 segments, T3-T5), the intercostal space (5 cadavers, median of 3.5 cm laterally), the T4 epidural space (6 cadavers), and the intervertebral foramina (4 cadavers, median of 2 segments, T4-T5). After T9 retrolaminar injection, dye was noted in the ipsilateral retrolaminar plane (5.5 cm cephalad, 13.5 cm caudad, and 2.5 cm lateral), the contralateral retrolaminar plane, and the epidural space. Dye after T4 traditional paravertebral block spread to T1-T6 paravertebral space with 15-cm lateral spread. CONCLUSIONS: Injectate spread to the paravertebral space, epidural space, intercostal space, and intervertebral foramina is possible in the RB but is quite variable. In comparison to the thoracic paravertebral block, injectate spread within the paravertebral space is more limited.

Association between Bispectral Index System and airway obstruction: an observational prospective cohort analysis during third molar extractions.

BACKGROUND: Sedation regimes during oral procedures frequently associated with airway obstruction. The aim of this study was to define the association of Bispectral Index (BIS) to the depth of sedation and airway obstruction events. METHODS: Forty-seven patients between 14-21 years old, who were candidates for 3rd molar teeth extraction, were enrolled in this study. Patients received a total of 4 mg midazolam, 100 microgram fentanyl followed by titrated incremental propofol in 10 mg. The Richmond Agitation Sedation Score (RASS) was used to assess the depth of sedation. Each patient was attached to BIS monitor, while clinicians were not involved in the data collection process. Apnea, airway obstruction, O2 saturation, timing and interventions for controlling the situation were recorded. All data was synchronized with BIS data monitoring. RESULTS: The results show that 97.5% of cases were ASA 1 and 2, with average age of 17.3 years (±1.4) and a median BMI of 26.1. By using linear regression, for every unit decrease of median RASS (less than zero), there was 1.78 decrease in mean BIS Score (P=0.045, 95% CI: 0.08-3.47). The mean BIS Index (over 1 minute) with airway obstruction was 64 (±10.2), which was significantly lower than the BIS during non-airway obstruction (77±11.6), (P<0.001). By using logistic regression analysis, for every on unit increase in BIS Index, there is 24% decrease in odds in having airway obstruction (P=0.0009, 95% CI: 0.65-8.94). CONCLUSIONS: This study demonstrates that the BIS could potentially be a valid continuous monitoring method to avoid airway obstruction during sedation for patients undergoing dental surgery.

Noise level measurement, a new method to evaluate effectiveness of sedation in pediatric dentistry.

OBJECTIVES: Pediatric dentists perform moderate sedation frequently to facilitate dental treatment in uncooperative children. Assessing the depth and quality of sedation is an important factor in the clinical utilization of moderate sedation. We aimed to determine if the level of noise, created by the children who are undergoing moderate sedation during dental procedures, could be used as a nonsubjective measurement of the depth of sedation and compare it to the Ohio State Behavior Rating Score (OSBRS). METHODS: Following Institutional Review Board approval and after receiving informed consent, we studied 51 children with a mean age of 4.2 years and average weight of 18.5 kg, who were undergoing restorative or extractive dental procedures, requiring moderate sedation. Sedation efficacy was assessed using OSBRS at several stages of the procedure. The noise level was measured by using a NoisePRO logging device to record the noise level at a rate of every second throughout the procedure. RESULTS: The depth of sedation assessed by OSBRS during the operative procedure was significantly correlated with noise level. The act of administering the local anesthesia and the operative procedure itself were two phases of the encounter that were significantly associated with higher OSBRS as well as noise levels. CONCLUSION: Measurement of noise level can be used as an effective guide to quantify the depth of sedation at different stages of the dental procedure. It is a nonsubjective and continuous measurement, which could be useful in clinical practice for the administration of moderate sedation during dental procedures. By using noise level analysis we are able to determine successful, poor, and failed sedation outcome.