MR Lymphangiography in Lymphatic Disorders: Clinical Applications, Institutional Experience, and Practice Development.

Lymphatic flow and anatomy can be challenging to study, owing to variable lymphatic anatomy in patients with diverse primary or secondary lymphatic pathologic conditions and the fact that lymphatic imaging is rarely performed in healthy individuals. The primary components of the lymphatic system outside the head and neck are the peripheral, retroperitoneal, mesenteric, hepatic, and pulmonary lymphatic systems and the thoracic duct. Multiple techniques have been developed for imaging components of the lymphatic system over the past century, with trade-offs in spatial, temporal, and contrast resolution; invasiveness; exposure to ionizing radiation; and the ability to obtain information on dynamic lymphatic flow. More recently, dynamic contrast-enhanced (DCE) MR lymphangiography (MRL) has emerged as a valuable tool for imaging both lymphatic flow and anatomy in a variety of congenital and acquired primary or secondary lymphatic disorders. The authors provide a brief overview of lymphatic physiology, anatomy, and imaging techniques. Next, an overview of DCE MRL and the development of an MRL practice and workflow in a hybrid interventional MRI suite incorporating cart-based in-room US is provided, with an emphasis on multidisciplinary collaboration. The spectrum of congenital and acquired lymphatic disorders encountered early in an MRL practice is provided, with emphasis on the diversity of imaging findings and how DCE MRL can aid in diagnosis and treatment of these patients. Methods such as DCE MRL for assessing the hepatic and mesenteric lymphatic systems and emerging technologies that may further expand DCE MRL use such as three-dimensional printing are introduced. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Causes of Perioperative Cardiac Arrest: Mnemonic, Classification, Monitoring, and Actions.

Perioperative cardiac arrest (POCA) is a catastrophic complication that requires immediate recognition and correction of the underlying cause to improve patient outcomes. While the hypoxia, hypovolemia, hydrogen ions (acidosis), hypo-/hyperkalemia, and hypothermia (Hs) and toxins, tamponade (cardiac), tension pneumothorax, thrombosis (pulmonary), and thrombosis (coronary) (Ts) mnemonic is a valuable tool for rapid differential diagnosis, it does not cover all possible causes leading to POCA. To address this limitation, we propose using the preload-contractility-afterload-rate and rhythm (PCARR) construct to categorize POCA, which is comprehensive, systemic, and physiologically logical. We provide evidence for each component in the PCARR construct and emphasize that it complements the Hs and Ts mnemonic rather than replacing it. Furthermore, we discuss the significance of utilizing monitored variables such as electrocardiography, pulse oxygen saturation, end-tidal carbon dioxide, and blood pressure to identify clues to the underlying cause of POCA. To aid in investigating POCA causes, we suggest the Anesthetic care, Surgery, Echocardiography, Relevant Check and History (A-SERCH) list of actions. We recommend combining the Hs and Ts mnemonic, the PCARR construct, monitoring, and the A-SERCH list of actions in a rational manner to investigate POCA causes. These proposals require real-world testing to assess their feasibility.

Association Between Antifibrinolytic Therapy and Perioperative Outcomes in Patients With Coronary Artery Stents Undergoing Noncardiac Surgery.

BACKGROUND: Patients with existing coronary artery stents are at an increased risk for major adverse cardiac events (MACEs) when undergoing noncardiac surgery (NCS). Although the use of antifibrinolytic (AF) therapy in NCS has significantly increased in the past decade, the relationship between perioperative AF use and its association with MACEs among patients with existing coronary artery stents has yet to be assessed. In this study, we aim to evaluate the association of MACEs in patients with existing coronary artery stents who receive perioperative AF therapy during orthopedic surgery. METHODS: A single-center retrospective cohort study was conducted in adult patients with existing coronary artery stents who underwent orthopedic surgery from 2008 to 2018. Two cohorts were established: patients with existing coronary artery stents who did not receive perioperative AF and patients with coronary artery stents who received perioperative AF. Associations between AF use and the primary outcome of MACEs within 30 days postoperatively and the secondary outcomes of thrombotic complications, excessive surgical bleeding, and intensive care unit (ICU) admissions were analyzed using logistic regression models. Inverse probability of treatment weighting was used to control for confounding. Secondary analyses examining the association between coronary stent type/timing and the outcomes of interest were performed using unadjusted logistic regression models. RESULTS: A total of 473 patients met study criteria, including 294 who did not receive AF and 179 patients who received AF. MACEs occurred in 15 (5.1%) patients who did not receive AF and 1 (0.6%) who received AF (P = .007). In weighted analyses, no significant difference was found in patients who received AF with regard to MACEs (odds ratio [OR] = 0.13, 95% confidence interval [CI], 0.01-1.74, P = .12), thrombotic complications (OR = 1.19, 95% CI, 0.53-2.68, P = .68), or excessive surgical bleeding (OR = 0.13, 95% CI, 0.01-2.23, P = .16) compared to patients who did not receive AF. CONCLUSIONS: The results of this study are inconclusive whether an association exists between perioperative AF use in patients with coronary artery stents and the outcome of MACEs compared to patients who did not receive perioperative AF therapy. The authors acknowledge that the imprecise CI hinders the ability to definitively determine whether an association exists in the study population. Further large prospective studies, powered to detect differences in MACEs, are needed to assess the safety of perioperative AF in patients with existing coronary artery stents and to clarify the mechanism of perioperative MACEs in this high-risk population.

Labor Analgesia in a Patient with Severe Dystrophic Calcinosis Cutis.

INTRODUCTION: Calcinosis cutis is a condition characterized by pathologic calcium deposition into superficial dermal skin layers. It is often associated with an autoimmune disease. However, it may also occur after minor localized trauma and infection. DESCRIPTION OF PROBLEM: We report a case of lumbar epidural placement of labor analgesia in a parturient with severe dystrophic calcinosis cutis without apparent complications. CLINICAL SOLUTION: We recommend fastidious optimization of epidural placement conditions for all patients who may be at high risk for neuraxial anesthesia, including consideration of ultrasound use, use of an experienced anesthesia provider for neuraxial placement, and placement in early labor. Additionally, judicious discussion of risks, benefits, and alternatives when obtaining informed consent is critical, ideally with the patient identified for a comprehensive visit in a preoperative obstetric anesthesia clinic before delivery.

Anesthesia With and Without Nitrous Oxide and Long-term Cognitive Trajectories in Older Adults.

BACKGROUND: We evaluated the hypothesis that the rate of postoperative decline in global cognition is greater in older adults exposed to general anesthesia with nitrous oxide (N2O) compared to general anesthesia without N2O. METHODS: Longitudinal measures of cognitive function were analyzed in nondemented adults, 70-91 years of age, enrolled in the Mayo Clinic Study of Aging. Linear mixed-effects models with time-varying covariates assessed the relationship between exposure to surgery with general anesthesia (surgery/GA) with or without N2O and the rate of long-term cognitive changes. Global cognition and domain-specific cognitive outcomes were defined using z scores, which measure how far an observation is, in standard deviations, from the unimpaired population mean. RESULTS: The analysis included 1819 participants: 280 exposed to GA without N2O following enrollment and before censoring during follow-up (median [interquartile range {IQR}] follow-up of 5.4 [3.9-7.9] years); 256 exposed to GA with N2O (follow-up 5.6 [4.0-7.9] years); and 1283 not exposed to surgery/GA (follow-up 4.1 [2.5-6.4] years). The slope of the global cognitive z score was significantly more negative following exposure to surgery/GA after enrollment (change in slope of -0.062 [95% confidence interval {CI}, -0.085 to -0.039] for GA without N2O, and -0.058 [95% CI, -0.080 to -0.035] for GA with N2O, both P < .001). The change in slope following exposure to surgery/GA did not differ between those exposed to anesthesia without versus with N2O (estimated difference -0.004 [95% CI, -0.035 to 0.026], P = .783). CONCLUSIONS: Exposure to surgery/GA is associated with a small, but statistically significant decline in cognitive z scores. Cognitive decline did not differ between anesthetics with and without N2O. This finding provides evidence that the use of N2O in older adults does not need to be avoided because of concerns related to decline in cognition.

Anesthesia and the brain after concussion.

PURPOSE OF REVIEW: To provide an overview of acute and chronic repeated concussion. We address epidemiology, pathophysiology, anesthetic utilization, and provide some broad-based care recommendations. RECENT FINDINGS: Acute concussion is associated with altered cerebral hemodynamics. These aberrations can persist despite resolution of signs and symptoms. Multiple repeated concussions can cause chronic traumatic encephalopathy, a disorder associated with pathologic findings similar to some organic dementias. Anesthetic utilization is common following concussion, especially soon after injury, a time when the brain may be most vulnerable to secondary injury. SUMMARY: Brain physiology may be abnormal following concussion and these abnormalities may persist despite resolutions of clinical manifestations. Those with recent concussion or chronic repeated concussion may be susceptible to secondary injury in the perioperative period. Clinicians should suspect concussion in any patient with recent trauma and strive to maintain cerebral homeostasis in the perianesthetic period.

Procedure-Focused Escape Room: A Pilot Study on Teaching High-Stakes Technical Skills in Anesthesia Residents.

Background: High-stakes yet clinically infrequent procedures are challenging to teach. Escape rooms may offer an innovative solution through game-based learning. There is limited guidance on how to design an escape room focused on physical puzzles. We designed and implemented a procedure-focused escape room to teach high-stakes procedures to anesthesiology residents. Methods: We selected 5 procedural skills relevant to anesthesiology residents through a modified Delphi technique: fiberoptic intubation, rapid infuser setup, intraosseous line placement, flexible bronchoscopy, and supraglottic airway exchange. We designed associated skills stations and linked them in sequence using an elaborate series of puzzles, locks, keys, and codes. The total cost of puzzle equipment was $169.53. After pilot testing, we implemented the escape room from July to November 2022. We assessed residents using a single group pretest-posttest study design. Results: Forty-three of 55 (78%) eligible anesthesiology residents participated in the escape room. Thirty-one residents completed the surveys. Resident self-efficacy significantly improved for each of the 5 procedures. Twenty-six of 27 (96%) residents preferred the escape room over a typical procedural skills workshop. Conclusions: This pilot study demonstrated the feasibility of a procedure-focused escape room for teaching high-stakes technical skills. We identified 3 lessons in procedure-focused escape room design: set participant caps intentionally, optimize resource usage, and maximize reproducibility. Participating in a single escape room session significantly increased resident self-efficacy. Residents strongly preferred the escape room format over a traditional procedural skills workshop.

A human cadaveric model for venous air embolism tool development.

Purpose: A human cadaveric model combining standard lung protective mechanical ventilation and modified cardiac bypass techniques was developed to allow investigation into automated modes of detection of venous air emboli (VAE) prior to in vivo human or animal investigations. Methods: In this study, in order to create an artificial cardiopulmonary circuit in a cadaver that could mimic VAE physiology, the direction of flow was reversed from conventional cardiac bypass. Saline was circulated in isolation through the heart and lungs as opposed to the peripheral organs by placing the venous cannula into the aorta and the arterial cannula into the inferior vena cava with selective ligation of other vessels. Results: Mechanical ventilation and this reversed cardiac bypass scheme allowed preliminary detection of VAE independently but not in concert in our current simulation scheme due to pulmonary edema in the cadaver. A limited dissection approach was used initially followed by a radical exposure of the great vessels, and both proved feasible in terms of air signal detection. We used electrical impendence as a preliminary tool to validate detection in this cadaveric model however we theorize that it would work for echocardiographic, intravenous ultrasound or other novel modalities as well. Conclusion: A cadaveric model allows monitoring technology development with reduced use of animal and conventional human testing.

Postgraduate-Year-1 Residents' Perceptions of Social Media and Virtual Applicant Recruitment: Cross-sectional Survey Study.

BACKGROUND: The dissemination of information about residency programs is a vital step in residency recruitment. Traditional methods of distributing information have been printed brochures, websites, in-person interviews, and increasingly, social media. Away rotations and in-person interviews were cancelled, and interviews were virtual for the first time during the COVID-19 pandemic. OBJECTIVE: The purpose of our study was to describe postgraduate-year-1 (PGY1) residents' social media habits in regard to residency recruitment and their perceptions of the residency programs' social media accounts in light of the transition to virtual interviews. METHODS: A web-based 33-question survey was developed to evaluate personal social media use, perceptions of social media use by residency programs, and perceptions of the residency program content. Surveys were sent in 2021 to PGY1 residents at Mayo Clinic in Arizona, Florida, and Minnesota who participated in the 2020-2021 interview cycle. RESULTS: Of the 31 program directors contacted, 22 (71%) provided permission for their residents to complete the survey. Of 219 residents who received the survey, 67 (30%) completed the survey. Most respondents applied to a single specialty, and greater than 61% (41/67) of respondents applied to more than 30 programs. The social media platforms used most regularly by the respondents were Instagram (42/67, 63%), Facebook (36/67, 54%), and Twitter (22/67, 33%). Respondents used the program website (66/67, 99%), residents (47/67, 70%), and social media (43/67, 64%) as the most frequent resources to research programs. The most commonly used social media platforms to research programs were Instagram (38/66, 58%), Twitter (22/66, 33%), and Doximity (20/66, 30%). The type of social media post ranked as most interesting by the respondents was "resident life outside of the hospital." In addition, 68% (39/57) of the respondents agreed or strongly agreed that their perception of a program was positively influenced by the residency program's social media account. CONCLUSIONS: In this multispecialty survey of PGY1 residents participating in the 2020-2021 virtual interview season, respondents preferred Instagram to Twitter or Facebook for gathering information on prospective residency programs. In addition, the program website, current residents, and social media platforms were the top-ranked resources used by prospective applicants. Having an up-to-date website and robust social media presence, particularly on Instagram, may become increasingly important in the virtual interview environment.

Under the Helmet: Perioperative Concussion-Review of Current Literature and Targets for Research.

Patients with recent concussion experience disruption in neurocellular and neurometabolic function that may persist beyond symptom resolution. Patients may require anesthesia to facilitate diagnostic or surgical procedures following concussion; these procedures may or may not be related to the injury that caused the patient to sustain a concussion. As our knowledge about concussion continues to advance, it is imperative that anesthesiologists remain up to date with current principles. This Focused Review will update readers on the latest concussion literature, discuss the potential impact of concussion on perianesthetic care, and identify knowledge gaps in our understanding of concussion.

Atypical dermatologic manifestations in complex regional pain syndrome: a case report.

BACKGROUND: Complex regional pain syndrome is a chronic pain condition characterized by autonomic dysfunction, changes in sympathetic and vasomotor activity, and sensory and motor changes. Complex regional pain syndrome is a clinical diagnosis and may occur after trauma or surgery. Complex regional pain syndrome-related pain may occur spontaneously and is out of proportion with the inciting event. We report herein the rare case of a man who developed concomitant painful generalized ulcerations after diagnosis of complex regional pain syndrome. CASE PRESENTATION: A 43-year-old Caucasian male with history of four-extremity complex regional pain syndrome type 2 secondary to right rotator cuff surgery performed at an outside hospital presented to a tertiary care center for treatment of generalized ulcerations on all extremities of unknown etiology. Dermatology performed an extensive work-up including laboratory evaluations and biopsies, which were relatively unremarkable. His ulcers were treated with vinegar-based dressings, hydrotherapy, and irrigation and debridements. He was started on methadone (replacing a home fentanyl patch), ketamine infusion, and amitriptyline in addition to his home adjuncts. He obtained good symptom control, improved sleep, and diminished cognitive slowing, compared with his fentanyl patches. CONCLUSION: This case report emphasizes an atypical case of generalized ulceration formation in the setting of complex regional pain syndrome. This case highlights the challenging nature of treating complex regional pain syndrome and using multimodal analgesia to target various nociceptive receptors to successfully reduce symptoms.

Getting the First Thousand-Optimizing Instagram Residency Content to Increase Followers During the COVID-19 Pandemic.

BACKGROUND: Social media remains a growing platform for physicians to facilitate learning, network, and disseminate information. The Coronavirus Disease 2019 (COVID-19) pandemic has challenged traditional medical student recruitment and outreach. Instagram is a platform that can be used by residency programs to increase engagement and as a potential recruitment tool. The authors present social media failed and successful strategies used to increase engagement and gain new followers. METHODS: In June 2020, an initiative began to use Instagram on a more frequent and intentional basis. Three different strategies were implemented during the pandemic: mirroring Twitter posts, increasing multimedia, and leveraging Instagram Stories. The outcomes of interest included number of followers and engagement on posts. Data were collected October 2020. RESULTS: After June 1, 2020, the @mayoanesthesia account gained 1000 followers through 127 days, an average of 4.26 new followers each day. Before June 1, there were 24 total posts over 3.3 years with a total of 458 followers. Three different strategies were implemented at different times during the pandemic. During the mirroring Twitter posts period, the mean number of interactions per post was 14.5. During the second phase after separating the Twitter and Instagram strategy, the mean number of interactions per post increased to 57.8. CONCLUSION: Residency programs can creatively, yet methodically, use Instagram posts to increase social media engagement during resident recruitment season during the COVID-19 pandemic and likely beyond.

Anesthesia During Positive-pressure Myelogram: A New Role for Cerebral Oximetry.

BACKGROUND: Positive-pressure myelogram (PPM) is an emerging radiologic study used to localize spinal dural defects. During PPM, cerebrospinal fluid pressure (CSFp) is increased by injecting saline with contrast into the cerebrospinal fluid. This has the potential to increase intracranial pressure and compromise cerebral perfusion. METHODS: We performed a retrospective chart review and analysis of 11 patients. The aim was to describe the periprocedural anesthetic management of patients undergoing PPM. RESULTS: All patients underwent PPM with general anesthesia and intra-arterial blood pressure and near-infrared spectroscopy monitoring of regional cerebral tissue oxygen saturation. Mean±SD maximum lumbar CSFp was 58±12 mm Hg. Upon intrathecal injection, mean systolic blood pressure increased from 115±21 to 142±32 mm Hg (P<0.001), diastolic blood pressure from 68±12 to 80±20 mm Hg (P≤0.001), and mean blood pressure from 87±10 to 98±14 mm Hg (P=0.02). Ten of 11 patients received blood pressure augmentation with phenylephrine to minimize the risk of reduced cerebral perfusion secondary to increased CSFp after intrathecal injection. The mean heart rate before and following injection was similar (68±15 vs. 70±15 bpm, respectively; P=0.16). There was a decrease in regional cerebral oxygen saturation after positioning from supine to prone position (79±10% to 74±9%, P=0.02) and a further decrease upon intrathecal injection (75±10% to 69±9%, P≤0.01). CONCLUSIONS: Systemic blood pressure increased following intrathecal injection during PPM, possibly due to a physiologic response to intracranial hypertension/reduced cerebral perfusion or administration of phenylephrine. Regional cerebral oxygen saturation decreased with the change to prone position and further decreased upon intrathecal injection. Cerebral near-infrared spectroscopy has a potential role to monitor the adequacy of cerebral perfusion and guide adjustment of systemic blood pressure during PPM.

Recent Preoperative Concussion and Postoperative Complications: A Retrospective Matched-cohort Study.

BACKGROUND: Physiological alterations during the perianesthetic period may contribute to secondary neurocognitive injury after a concussion. METHODS: Patients exposed to concussion and who received an anesthetic within 90 days were matched to unexposed patients without concussion. Intraoperative and postoperative events were compared. Subgroup analyses assessed relationships among patients with a concussion in the prior 30, 31 to 60, and 61 to 90 days and their respective unexposed matches. To facilitate identification of potential targets for further investigation, statistical comparisons are reported before, as well as after, correction for multiple comparisons. RESULTS: Sixty concussion patients were matched to 176 unexposed patients. Before correction, 28.3% postconcussion versus 14.8% unexposed patients reported postanesthesia care unit pain score≥7 (P=0.02); 16.7% concussion versus 6.5% unexposed patients reported headache within 90 days of anesthesia (P=0.02) and 23.5% of patients who received surgery and anesthesia within 30 days of concussion experienced headache within 90 days of anesthesia compared with 7.1% in the unexposed group (P=0.01). Patients who experienced concussion and had anesthesia between 31 and 60 days after injury had a postanesthesia care unit Richmond Agitation and Sedation Scale score of -1.61±1.29 versus a score of -0.2±0.45 in unexposed patients (P=0.002). After adjusting the P-value threshold for multiple comparisons, the P-value for significance was instead 0.0016 for the overall cohort. Our study revealed no significant associations with application of adjusted significance thresholds. CONCLUSIONS: There were no differences in intraoperative and postoperative outcomes in patients with recent concussion compared with unexposed patients. Before correction for multiple comparisons, several potential targets for further investigation are identified. Well-powered studies are warranted.

Intraoperative Management of Large Resuscitation-Associated Venous Air Embolism (VAE) for Emergent Neurological Surgery.

Venous air embolism (VAE) is a well-described phenomenon that may have life-threatening cardiopulmonary and neurological consequences. Accidental administration of air during resuscitation while using a rapid infuser is rare. Furthermore, there is a paucity of published data describing the intraoperative management of VAE during emergent nonseated neurological surgery. We report a 22-year-old previously healthy female who experienced a motor vehicle accident with severe facial and head trauma, and mixed subdural and epidural hematomas with an 8 mm midline shift. Computed tomography revealed significant air entrainment in the right heart and main pulmonary artery, with venous air tracking from the right axillary vein. Given her age, lack of preexisting cardiac comorbidities, hemodynamic stability, and critical cerebral herniation risk, further cardiac evaluation was deferred, and the patient was transferred to the operating room for emergent decompressive craniotomy. Intraoperatively, she experienced acute decrease in mean arterial pressure and end-expiratory carbon-dioxide with loss of pulse oximetry waveform concerning for obstructive VAE physiology. She was responsive to fluid resuscitation and epinephrine administration and did not experience any recurrence of obstructive VAE. This challenging case report describes positive neurologic and hemodynamic outcomes after resuscitation-associated VAE and cardiopulmonary collapse during emergency neurosurgery. Comprehensive evaluation of risk, urgency of procedure, and need for diagnostic monitoring and treatment should be personalized.

Neuroanesthesia Practice During the COVID-19 Pandemic: Recommendations From Society for Neuroscience in Anesthesiology and Critical Care (SNACC).

The pandemic of coronavirus disease 2019 (COVID-19) has several implications relevant to neuroanesthesiologists, including neurological manifestations of the disease, impact of anesthesia provision for specific neurosurgical procedures and electroconvulsive therapy, and health care provider wellness. The Society for Neuroscience in Anesthesiology and Critical Care appointed a task force to provide timely, consensus-based expert guidance for neuroanesthesiologists during the COVID-19 pandemic. The aim of this document is to provide a focused overview of COVID-19 disease relevant to neuroanesthesia practice. This consensus statement provides information on the neurological manifestations of COVID-19, advice for neuroanesthesia clinical practice during emergent neurosurgery, interventional radiology (excluding endovascular treatment of acute ischemic stroke), transnasal neurosurgery, awake craniotomy and electroconvulsive therapy, as well as information about health care provider wellness. Institutions and health care providers are encouraged to adapt these recommendations to best suit local needs, considering existing practice standards and resource availability to ensure safety of patients and providers.

Outcomes in single-level posterior cervical spine surgeries performed in the sitting and prone positions.

OBJECTIVE: The sitting or semisitting position in neurosurgery allows for several technical advantages, including improved visualization of the surgical field. However, it has also been associated with an increased risk of venous air embolisms and positioning-related complications that limit its commonplace adoption. The authors report a large, single-center series of cervical spine procedures performed with patients in the sitting or prone position in order to assess the perceived risk of intraoperative and postoperative complications associated with the sitting position. METHODS: Noninstrumented, single-level posterior cervical spine procedures performed with patients in the sitting/semisitting or prone position from 2000 to 2016 at a single institution were reviewed. Institutional abstraction tools (DataMart and Chart Plus) were used to collect data from the medical records. The two positions were compared with regard to preoperative factors, intraoperative variables, and postoperative outcomes. Multivariable logistic regression models were fitted for 30-day readmission, 30-day return to the operating room, and complication rates. RESULTS: A total of 750 patients (sitting, n = 480; prone, n = 270) were analyzed. The median age was 53 years for those who underwent surgery in the prone position and 50 years for those who underwent surgery in the sitting position (IQRs 45-62 years and 43-60 years, respectively), and 35% of the patients were female. Sitting cases were associated with significantly longer anesthetic times (221 minutes [range 199-252 minutes] vs 205 minutes [range 179-254 minutes]) and operative times (126 minutes [range 101-163 minutes] vs 149 minutes [120-181 minutes]). Cardiorespiratory events in the postanesthesia care unit (PACU) were comparable between the two groups, with the exception of episodes of apnea (2.6% vs 0.6%, p = 0.041) and hypoventilation (4.4% vs 0.8%, p < 0.003), which were more frequent in the prone-position cohort. On multivariable analysis, the effect of the sitting versus the prone position was not significant for 30-day readmission (OR 0.77, 95% CI 0.34-1.71, p = 0.52) or reoperation (OR 0.71, 95% CI 0.31-1.60, p = 0.40). The sitting position was associated with lower odds of developing any complication (OR 0.31, 95% CI 0.16-0.62, p < 0.001). CONCLUSIONS: Based on the intraoperative and postoperative complications chosen in this study, the sitting position confers a similar safety profile to the prone position. This can be explained by a more anatomic positioning accounting for reduced temporary neurological deficits and reduced PACU-associated hypoventilation noted in this series. Nevertheless, the findings may also reflect institutional familiarity, experience, and mastery of this position type, and outcomes may not reflect practices in general.

Failed interleukin-6 signal transduction in murine sepsis: attenuation of hepatic glycoprotein 130 phosphorylation.

OBJECTIVE: Sepsis impairs the activation of the interleukin (IL)-6 dependent transcription factor signal transducer and activator of transcription (STAT)-3. However, the molecular basis for depressed functionality has not been characterized. In this study, we test the hypothesis that altered signal transduction results from a change in the activation state of one or more of the components of the intracellular IL-6-linked pathway. DESIGN: Randomized prospective experimental study. SETTING: University medical laboratory. SUBJECTS: Male, 6-8-week-old C57/Bl6 mice. INTERVENTIONS: Cecal ligation and single puncture (CLP) or cecal ligation and double puncture (2CLP) was used to model mild and fulminant sepsis, respectively. Sham-operated and unoperated animals served as controls. All animals were fluid resuscitated at the time of surgery and every 24 hours thereafter. Surviving animals were euthanized at 3, 6, 16, 24, 48, and 72 hours; blood samples were obtained and liver tissue was harvested. MEASUREMENTS AND MAIN RESULTS: Serum IL-6 levels were elevated in both CLP and 2CLP relative to controls. STAT-3 DNA binding activity and nuclear phosphorylated-STAT-3 levels were elevated in CLP but decreased abruptly 24 hours after 2CLP. This 2CLP-induced alteration was associated with attenuated phosphorylation of the key transcellular glycoprotein (gp) 130. Abundance and phosphorylation of the other key component of IL-6 signal transduction pathway, janus kinase-1, was unchanged following either CLP or 2CLP. 2CLP also did not cause disassociation of the gp130-janus kinase-1 complex. CONCLUSIONS: Impaired gp130 phosphorylation may be responsible for IL-6 hyporesponsiveness during sepsis.

Urgent Repositioning After Venous Air Embolism During Intracranial Surgery in the Seated Position: A Case Series.

BACKGROUND: Venous air embolism (VAE) is a well-described complication of neurosurgical procedures performed in the seated position. Although most often clinically insignificant, VAE may result in hemodynamic or neurological compromise resulting in urgent change to a level position. The incidence, intraoperative course, and outcome in such patients are provided in this large retrospective study. METHODS: Patients undergoing a neurosurgical procedure in the seated position at a single institution between January 2000 and October 2013 were identified. Corresponding medical records, neurosurgical operative reports, and computerized anesthetic records were searched for intraoperative VAE diagnosis. Extreme VAE was defined as a case in which urgent seated to level position change was performed for patient safety. Detailed examples of extreme VAE cases are described, including their intraoperative course, VAE management, and postoperative outcomes. RESULTS: There were 8 extreme VAE (0.47% incidence), 6 during suboccipital craniotomy (1.5%) and 2 during deep brain stimulator implantation (0.6%). VAE-associated end-expired CO2 and mean arterial pressure reductions rapidly normalized following position change. No new neurological deficits or cardiac events associated with extreme VAE were observed. In 5 of 8, surgery was completed. Central venous catheter placement and aspiration during VAE played no demonstrable role in patient outcome. CONCLUSIONS: Extreme VAE during seated intracranial neurosurgical procedures is infrequent. Extreme VAE-associated CO2 exchange and hemodynamic consequences from VAE were transient, recovering quickly back to baseline without significant neurological or cardiopulmonary morbidity.