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Objective Deep extubation refers to endotracheal extubation performed while a patient is deeply anesthetized and without airway reflexes. After deep extubation, patients are sent to the post-anesthesia care unit (PACU) to recover, an area with notably different management and staffing than the operating room (OR). One of the most frequent and concerning complications to occur in the PACU is hypoxemia. As such, this study seeks to evaluate the incidence of desaturation, defined by SpO2 Results Following deep extubation, 4.3% of patients (13/300) experienced desaturation in the PACU. Every episode was notably minor, with patients reverting to normal saturation levels within a minute. Of the 26 case factors assessed, 24 had no significant association desaturation in the PACU, including the amount of time spent in the PACU. History of asthma was the only statistically significant factor found to be positively associated with desaturation. We find that PACU desaturation episodes following deep extubation are rare. Our findings suggest that deep extubation is a viable and safe option for patients without significant respiratory tract pathology.

BackgroundRegional anesthetic techniques have become increasingly used for the purpose of pain management following mastectomy. Although a variety of beneficial techniques have been described, the delivery of regional anesthesia following mastectomy has yet to be examined for racial or ethnic disparities. We aimed to examine the association of race and ethnicity on the delivery of regional anesthesia in patients undergoing surgical mastectomy using a large national database.MethodsWe used the American College of Surgeons–National Surgical Quality Improvement Program database to identify adult patients aged ≥18 years old who underwent mastectomy from 2014 to 2016. We reported unadjusted estimates of regional anesthesia accordingly to race and ethnicity and examined differences in sociodemographic characteristics and health status. Multivariable logistic regression was used to report the association of race and ethnicity with use of regional anesthesia.ResultsA total of 81 345 patients who underwent mastectomy were included, 14 887 (18.3%) of whom underwent regional anesthesia. The unadjusted rate of use of regional anesthesia was 18.9% for white patients, 16.8% for black patients, 15.6% for Asian patients, 16.5% for Native Hawaiian/Pacific Islander patients, 17.8% for American Indian or Alaska Native and 17.4% for unknown race (pConclusionBlack and Asian patients had lower odds of undergoing regional anesthesia following mastectomy compared with white counterparts. In addition, Hispanic patients had lower odds of undergoing regional anesthesia than non-Hispanic counterparts. These differences underlie the importance of working to deliver equitable healthcare irrespective of race or ethnicity.

Orai1, the first identified member of the Orai protein family, is ubiquitously expressed in the animal kingdom. Orai1 was initially characterized as the channel responsible for the store-operated calcium entry (SOCE), a major mechanism that allows cytosolic calcium concentration increments upon receptor-mediated IP3 generation, which results in intracellular Ca2+ store depletion. Furthermore, current evidence supports that abnormal Orai1 expression or function underlies several disorders. Orai1 is, together with STIM1, the key element of SOCE, conducting the Ca2+ release-activated Ca2+ (CRAC) current and, in association with TRPC1, the store-operated Ca2+ (SOC) current. Additionally, Orai1 is involved in non-capacitative pathways, as the arachidonate-regulated or LTC4-regulated Ca2+ channel (ARC/LRC), store-independent Ca2+ influx activated by the secretory pathway Ca2+-ATPase (SPCA2) and the small conductance Ca2+-activated K+ channel 3 (SK3). Furthermore, Orai1 possesses two variants, Orai1α and Orai1β, the latter lacking 63 amino acids in the N-terminus as compared to the full-length Orai1α form, which confers distinct features to each variant. Here, we review the current knowledge about the differences between Orai1α and Orai1β, the implications of the Ca2+ signals triggered by each variant, and their downstream modulatory effect within the cell.

Supplemental Digital Content is available in the text., Background: Hutchinson-Gilford progeria syndrome (HGPS) is a rare disorder characterized by premature aging and death mainly because of myocardial infarction, stroke, or heart failure. The disease is provoked by progerin, a variant of lamin A expressed in most differentiated cells. Patients look healthy at birth, and symptoms typically emerge in the first or second year of life. Assessing the reversibility of progerin-induced damage and the relative contribution of specific cell types is critical to determining the potential benefits of late treatment and to developing new therapies. Methods: We used CRISPR-Cas9 technology to generate LmnaHGPSrev/HGPSrev (HGPSrev) mice engineered to ubiquitously express progerin while lacking lamin A and allowing progerin suppression and lamin A restoration in a time- and cell type–specific manner on Cre recombinase activation. We characterized the phenotype of HGPSrev mice and crossed them with Cre transgenic lines to assess the effects of suppressing progerin and restoring lamin A ubiquitously at different disease stages as well as specifically in vascular smooth muscle cells and cardiomyocytes. Results: Like patients with HGPS, HGPSrev mice appear healthy at birth and progressively develop HGPS symptoms, including failure to thrive, lipodystrophy, vascular smooth muscle cell loss, vascular fibrosis, electrocardiographic anomalies, and precocious death (median lifespan of 15 months versus 26 months in wild-type controls, P

Background: Andersen-Tawil syndrome type 1 (ATS1), caused by trafficking deficient mutations in the gene KCNJ2 coding the inward rectifier K + channel Kir2.1, is associated with life-threatening arrhythmias, which in some patients resemble catecholaminergic polymorphic ventricular tachycardia (CPVT), but the mechanisms are poorly understood. We tested the hypothesis that dysfunction of two different populations of mutant Kir2.1 channels, one at the sarcolemma, and the other at the sarcoplasmic reticulum (SR) membrane, directly alters conduction and intracellular calcium dynamics, respectively, to promote the ATS1 phenotype and arrhythmias that resemble CPVT. Methods: We generated a new mouse model of ATS1 by a single i.v. injection of cardiac specific adeno-associated viral (AAV) transduction with Kir2.1 Δ314-315 . In-vivo and cellular, structural and functional analyses of the model were carried out by electrocardiogram (ECG), magnetic resonance imaging (MRI), intracardiac stimulation, patch-clamping, membrane fractionation, western blot, immunolocalization and live calcium imaging. Results: Our mouse model carrying mutant Kir2.1 Δ314-315 recapitulated the ATS1 phenotype without modifying ventricular function. On ECG, Kir2.1 Δ314-315 mice had prolonged PR, QRS and QT intervals and occasional U waves. They showed significantly slower conduction velocities than wildtype mice in response to flecaidine-induced Na + -channel blockade, additional QT prolongation in response to isoproterenol, and increased vulnerability to cardiac fibrillation. Cardiomyocytes from Kir2.1 Δ314-315 mice had significantly reduced inward rectifier K + and Na + inward currents, depolarized resting membrane potential and prolonged action potential duration. Immunolocalization in wildtype cardiomyocytes and skeletal muscle cells revealed a novel SR microdomain of functional Kir2.1 channels contributing to intracellular Ca 2+ homeostasis. Kir2.1 Δ314-315 cardiomyocytes showed defects in SR Kir2.1 localization and function, which contributed to abnormal spontaneous Ca 2+ release events. Conclusions: Cardiac-specific AAV transduction with Kir2.1 Δ314-315 in mice recapitulates the ATS1 phenotype by disrupting localization and function of Kir2.1 channels at the SR, and the Kir2.1-Na V 1.5 channelosome at the sarcolemma. These results reveal a novel dual mechanism of arrhythmogenesis in ATS1 involving defects in Kir2.1 channel trafficking and function at two different microdomains. They also provide the first demonstration at the molecular level of the mechanism underlying the overlap between ATS1 and CPVT associated with defects in intracellular calcium homeostasis.

Ventilation during microlaryngoscopy previously included jet ventilation, microlaryngeal endotracheal tubes, and extended apnea. Historically, apneic oxygenation provided a tubeless field but limited operative time. Increased utilization of high-flow nasal cannula in intensive care units and operating rooms has created new opportunities to expand tubeless microlaryngoscopy. Although few studies have described high-flow nasal cannula for microlaryngoscopy, there remains much to be explored. In this case report, we describe the unique setting of utilizing high-flow nasal cannula in a spontaneously breathing patient to create an optimal tubeless surgical field for both microlaryngoscopy and vocal cord electromyography.

This paper addresses the design of a systemic management to improve the energetic efficiency of an open cathode proton exchange membrane fuel cell (PEMFC) in a hybrid system. Unlike the other similar works, the proposed approach capitalizes on the usage of both thermal management strategy and current control to meet the requested power from the system by the minimum fuel consumption. To do so, firstly, an experimentally based 3D mapping is performed to relate the requested power form the PEMFC to its operating temperature and current. Secondly, the reference temperature which leads to gaining the demanded power by the minimum current level is determined to minimize the hydrogen consumption. Finally, the temperature control is formulated by an optimized fuzzy logic scheme to reach the determined reference temperature by acting on the cooling fan of the PEMFC system, whilst the current is being regulated by its controller. The inputs of the fuzzy controller are the PEMFC current and temperature error and the sole output is the duty factor of the fan. The proposed methodology is tested on an experimental test bench to be better evaluated in a real condition. The obtained results from the proposed systemic management indicate promising enhancement of the system efficiency compared to a commercial controller. The proposed method of this work is extendable and applicable in fuel cell hybrid electric vehicles.

Andersen-Tawil Syndrome (ATS) is associated with life threatening arrhythmias of unknown mechanism. We report on a mouse model carrying the trafficking-deficient mutant Kir2.1Δ314-315. The mouse recapitulates the electrophysiological phenotype of type 1 (ATS1), with slower conduction velocities in response to flecainide, QT prolongation exacerbated by isoproterenol, and increased vulnerability to calcium-mediated arrhythmias resembling catecholaminergic polymorphic ventricular tachycardia (CPVT). Kir2.1Δ314-315 expression significantly reduced inward rectifier K+ and Na+ inward currents, depolarized resting membrane potential and prolonged action potential duration. Immunolocalization in wildtype cardiomyocytes and skeletal muscle cells revealed a novel sarcoplasmic reticulum (SR) microdomain of functional Kir2.1 channels contributing to intracellular Ca2+ homeostasis. Kir2.1Δ314-315 cardiomyocytes showed defects in SR Kir2.1 localization and function, which contributed to abnormal spontaneous Ca2+ release events. This is the first in-vivo demonstration of a dual arrhythmogenic mechanism of ATS1 defects in Kir2.1 channel function at the sarcolemma and the SR, with overlap between ATS1 and CPVT.

Aims The aim of this study was to study changes in coronary microcirculation status during and after several cycles of anthracycline treatment. Methods and results Large-white male pigs (n=40) were included in different experimental protocols (ExPr.) according to anthracycline cumulative exposure [0.45 mg/kg intracoronary (IC) doxorubicin per injection] and follow-up: control (no doxorubicin); single injection and sacrifice either at 48 h (ExPr. 1) or 2 weeks (ExPr. 2); 3 injections 2 weeks apart (low cumulative dose) and sacrifice either 2 weeks (ExPr. 3) or 12 weeks (ExPr. 4) after third injection; five injections 2 weeks apart (high cumulative dose) and sacrifice 8 weeks after fifth injection (ExPr. 5). All groups were assessed by serial cardiac magnetic resonance (CMR) to quantify perfusion and invasive measurement of coronary flow reserve (CFR). At the end of each protocol, animals were sacrificed for ex vivo analyses. Vascular function was further evaluated by myography in explanted coronary arteries of pigs undergoing ExPr. 3 and controls. A single doxorubicin injection had no impact on microcirculation status, excluding a direct chemical toxicity. A series of five fortnightly doxorubicin injections (high cumulative dose) triggered a progressive decline in microcirculation status, evidenced by reduced CMR-based myocardial perfusion and CFR-measured impaired functional microcirculation. In the high cumulative dose regime (ExPr. 5), microcirculation changes appeared long before any contractile defect became apparent. Low cumulative doxorubicin dose (three bi-weekly injections) was not associated with any contractile defect across long-term follow-up, but provoked persistent microcirculation damage, evident soon after third dose injection. Histological and myograph evaluations confirmed structural damage to arteries of all calibres even in animals undergoing low cumulative dose regimes. Conversely, arteriole damage and capillary bed alteration occurred only after high cumulative dose regime. Conclusion Serial in vivo evaluations of microcirculation status using state-of-the-art CMR and invasive CFR show that anthracyclines treatment is associated with progressive and irreversible damage to the microcirculation. This long-persisting damage is present even in low cumulative dose regimes, which are not associated with cardiac contractile deficits. Microcirculation damage might explain some of the increased incidence of cardiovascular events in cancer survivors who received anthracyclines without showing cardiac contractile defects., Graphical Abstract

Background: Endotracheal extubation is the most crucial step during emergence from general anesthesia. In the vast majority of cases, this is carried out when patients are awake with return of airway reflexes. Alternatively, extubations can also be accomplished while patients are deeply anesthetized, a technique known as “deep extubation”, in order to provide a “smooth” emergence from anesthesia. This smooth emergence is particularly important for procedures that require maintenance of stable levels of intraocular and intracranial pressures, such as in neurologic, ophthalmic, and head-and-neck surgery [1]. Reluctance to performing deep extubation in adults, even in appropriate circumstances, is common and likely derives both from concerns for potential respiratory complications [2] and limited research supporting its safety. It is in this context that we designed our prospective study to understand the factors that contribute to the success or failure of deep extubation in adults. Methods: In this prospective observational study, 300 patients, age ≥ 18, American Society of Anesthesiologists Physical Status (ASA PS) Classification I - III, who underwent head-and-neck and ocular surgeries. Patients’ demographic, comorbidity, airway assessment, O2 saturation, end tidal CO2 levels, time to exit OR, time to eye opening, and respiratory complications after deep extubation in the OR were analyzed. Results: Forty (13%) out of 300 patients had at least one complication in the OR, as defined by persistent coughing, desaturation SpO2 < 90% for longer than 10s, laryngospasm, stridor, bronchospasm and reintubation. When comparing the complication group to the no complication group, the patients in the complication group had significantly higher BMI (30 vs 26), lower O2 saturation pre and post extubation, and longer time from end of surgery to out of OR (pConclusions: The complication rate during deep extubation in adults was low and all easily reversible. And patient factors and extubation conditions may influence probability of success in deep extubation.

Aims Hutchinson–Gilford progeria syndrome (HGPS) is an ultrarare laminopathy caused by expression of progerin, a lamin A variant, also present at low levels in non-HGPS individuals. HGPS patients age and die prematurely, predominantly from cardiovascular complications. Progerin-induced cardiac repolarization defects have been described previously, although the underlying mechanisms are unknown. Methods and results We conducted studies in heart tissue from progerin-expressing LmnaG609G/G609G (G609G) mice, including microscopy, intracellular calcium dynamics, patch-clamping, in vivo magnetic resonance imaging, and electrocardiography. G609G mouse cardiomyocytes showed tubulin-cytoskeleton disorganization, t-tubular system disruption, sarcomere shortening, altered excitation–contraction coupling, and reductions in ventricular thickening and cardiac index. G609G mice exhibited severe bradycardia, and significant alterations of atrio-ventricular conduction and repolarization. Most importantly, 50% of G609G mice had altered heart rate variability, and sinoatrial block, both significant signs of premature cardiac aging. G609G cardiomyocytes had electrophysiological alterations, which resulted in an elevated action potential plateau and early afterdepolarization bursting, reflecting slower sodium current inactivation and long Ca+2 transient duration, which may also help explain the mild QT prolongation in some HGPS patients. Chronic treatment with low-dose paclitaxel ameliorated structural and functional alterations in G609G hearts. Conclusions Our results demonstrate that tubulin-cytoskeleton disorganization in progerin-expressing cardiomyocytes causes structural, cardiac conduction, and excitation–contraction coupling defects, all of which can be partially corrected by chronic treatment with low dose paclitaxel., Graphical Abstract

Study objective It is unclear what the body mass index (BMI) should be when performing surgery involving the airway at an outpatient surgery facility. The objective of this study was to evaluate the association of Class 3 obesity versus a composite cohort of Class 1 and 2 obesity with same-day hospital admission following outpatient tonsillectomy in adults. Design Retrospective cohort study. Setting Multi-institutional. Patients Patients undergoing outpatient tonsillectomy. Intervention None. Measurements We used the National Surgical Quality Improvement Program (NSQIP) to analyze association of BMI to same-day admission and 30-day readmission following outpatient tonsillectomy from 2017 to 2019. We looked at six BMI cohorts: 1) ≥30 and Main results There were 12,287 patients included in the final analysis, at which 697 (5.7%) and 283 (2.3%) had a same-day admission or 30-day readmission, respectively. On Poisson regression with robust standard errors, the relative risks for BMI ≥40 kg/m2 and Conclusion These results contribute data that may help practices – especially freestanding ambulatory surgery centers – decide appropriate BMI cutoffs for surgery involving the airway. Whether this is considered clinically significant enough to rule out eligibility will differ from practice-to-practice and will depend on surgical volume, resources available and financial interests.

Background Hypothermia is common in many plastic surgery procedures, but few measures to prevent its occurrence are taken. Objectives This study evaluated the effect of hypothermia in patients undergoing plastic surgery procedures and the effect of utilizing simple and inexpensive measures to prevent patient hypothermia during surgery. Methods A randomized controlled clinical trial was performed among 3 groups of patients who underwent body contouring surgery for longer than 3.5 hours. In group 1, no protective measures were taken to prevent hypothermia; in group 2, maneuvers were applied intraoperatively for the duration of the entire surgical procedure; and in group 3, measures were taken preoperatively and intraoperatively. The results were quantified and analyzed through a bivariate analysis, including degree of hypothermia, anesthesia recovery time, time spent in the recovery area, intensity of pain, cold perception, response to opioids, and nausea. Results There were 122 patients included in the study: 43 in group 1, 39 in group 2, and 40 in group 3. All patients in group 1 had a higher degree of hypothermia, longer recovery time from anesthesia, longer overall recovery time, increased pain, increased feeling of cold, and more nausea. These patients also required a greater amount of opioids compared with the patients in groups 2 and 3. Many of the results were statistically significant. Conclusions The adoption of simple and inexpensive measures before and during plastic surgery can prevent patient hypothermia during the procedures, leading to a shorter anesthesia recovery time and avoiding the undesirable effects associated with hypothermia. In addition, these measures may have significant economic savings. Level of Evidence 2

Aging is the main risk factor for cardiovascular and metabolic diseases, which have become a global concern as the world population ages. These diseases and the aging process are exacerbated in Hutchinson–Gilford progeria syndrome (HGPS or progeria). Here, we evaluated the cardiometabolic disease in animal models of premature and normal aging with the aim of identifying alterations that are shared or specific to each condition. Despite differences in body composition and metabolic markers, prematurely and normally aging mice developed heart failure and similar cardiac electrical abnormalities. High‐throughput proteomics of the hearts of progeric and normally aged mice revealed altered protein oxidation and glycation, as well as dysregulated pathways regulating energy metabolism, proteostasis, gene expression, and cardiac muscle contraction. These results were corroborated in the hearts of progeric pigs, underscoring the translational potential of our findings, which could help in the design of strategies to prevent or slow age‐related cardiometabolic disease., We have evaluated cardiac and metabolic disease in animal models of aging. Despite differences in body composition, progeric and normally aged mice developed heart failure and similar cardiac electrical alterations. High‐throughput proteomics of the hearts of these animals revealed dysregulation of energy metabolism, proteostasis, gene expression, and cardiac contraction pathways. These results were corroborated in progeric pigs, underscoring the translational potential of our findings.

Gluteal augmentation with fat has become one of the most common cosmetic procedures worldwide. Gluteal augmentation is designed to increase the volume and contour of the gluteal region. Intramuscular lipoinjection has been linked to multiple reports of severe complications, including death due to macro fat embolism (MAFE). The authors present the first reported case of survival and successful recovery after MAFE secondary to gluteal augmentation with fat. A 41-year-old woman, ASA II, was scheduled for augmentation mammaplasty, liposuction, and gluteal augmentation with fat. The patient was operated under general anesthesia with a total intravenous anesthesia technique. A total of 3.5 liters of fat was liposuctioned with no complications. The patient was then positioned in a lateral decubitus position for gluteal augmentation with fat. Right after the last injection, the anesthesiologist noticed a sudden change in capnography followed by hypotension, bradycardia, and hypoxemia. The first reaction in the operating room was to consider that the patient was experiencing a severe episode of fat embolism. She was then resuscitated and transferred to a tertiary facility for intensive care management. To our knowledge, this is the first case report of successful resuscitation in a patient experiencing severe MAFE after gluteal augmentation with fat. We believe that this patient survived the event due to early detection, aggressive management, and proper transfer to an intensive care unit. Level of Evidence: 5

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder for which no cure exists. The disease is characterized by premature aging and inevitable death in adolescence due to cardiovascular complications. Most HGPS patients carry a heterozygous de novo LMNA c.1824C > T mutation, which provokes the expression of a dominant-negative mutant protein called progerin. Therapies proven effective in HGPS-like mouse models have yielded only modest benefit in HGPS clinical trials. To overcome the gap between HGPS mouse models and patients, we have generated by CRISPR-Cas9 gene editing the first large animal model for HGPS, a knockin heterozygous LMNA c.1824C > T Yucatan minipig. Like HGPS patients, HGPS minipigs endogenously co-express progerin and normal lamin A/C, and exhibit severe growth retardation, lipodystrophy, skin and bone alterations, cardiovascular disease, and die around puberty. Remarkably, the HGPS minipigs recapitulate critical cardiovascular alterations seen in patients, such as left ventricular diastolic dysfunction, altered cardiac electrical activity, and loss of vascular smooth muscle cells. Our analysis also revealed reduced myocardial perfusion due to microvascular damage and myocardial interstitial fibrosis, previously undescribed readouts potentially useful for monitoring disease progression in patients. The HGPS minipigs provide an appropriate preclinical model in which to test human-size interventional devices and optimize candidate therapies before advancing to clinical trials, thus accelerating the development of effective applications for HGPS patients. This project was mainly supported by an Established Investigator Award from the Progeria Research Foundation (2014-52), and from the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU), and the European Regional Development Fund (FEDER, “A way to build Europe”) (SAF2016-79490-R, CB16/11/00405). Ana Barettino has a predoctoral contract from MCIU (BES-2017-079705). Work at Universidad de Murcia is supported by Fundación Seneca-Agencia de Ciencia y Tecnología de la Región de Murcia (20040/GERM/16). The CNIC is supported by the MCIU and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505). Sí

Introduction Hypothermia is perhaps the most frequent undesirable event in elective surgery. It is estimated that 1 h after surgery has initiated 70–90% of patients will experience hypothermia. In elective surgery, there are several factors leading to temperatures under 34 °C. Hypothermia may increases infections, bleeding and need for transfusion as well as the occurrence of an undesirable effect of discomfort and feared such as cold and postoperative shivering that can lead to cardiac complications due to increased of sympathetic influence. Objectives Review the causes of these low temperatures within intraoperative elective surgery and check if the current alternatives to prevent hypothermia are effective. Methods Review of non-systematic literature in PubMed and Medline was performed. Results Hypothermia is the most common and least diagnosed undesirable event of patients undergoing surgery although it is easy to detect and preventive measures do not present major difficulties in their implementation. Conclusions There are effective measures easy to set up, economical and effective to prevent hypothermia; the most important is the patient warm with hot air under pressure for 1 h and maintenance of air conditioning in the room above 22 °C. We just need to understand these measures and start to implement them.

Background Although intraoperative nerve monitoring (IONM) is utilized increasingly, the information on the related anesthesia technique is limited. This study presents an up-to-date clinical algorithm, including setup and troubleshooting of an IONM system, endotracheal tube placement, and anesthetic parameters. To our knowledge, this is the first interdisciplinary collaborative protocol for monitored neck surgery based on the published evidence and clinical experience. Methods The Departments of Otolaryngology Head and Neck Surgery, Anesthesiology, and Audiology collaboratively developed a protocol for IONM of the recurrent laryngeal nerve (RLN) based on published evidence and our experience with 3000 patients over a 16-year period. Results No complications related to monitoring or endotracheal tube placement were noted when the IONM protocol was implemented at Massachusetts Eye and Ear Infirmary (MEEI). The IONM protocol has proven to be vital in standardizing care and in avoiding intraoperative errors. Conclusion An IONM system entails an anesthesiologist who understands the challenges posed by this technique; muscle relaxation must be minimized/eliminated to optimize IONM. © 2016 Wiley Periodicals, Inc. Head Neck 38: First–1494, 2016

Background: Isoflurane may be protective in preclinical models of lung injury, but its use in patients with lung injury remains controversial and the mechanism of its protective effects remains unclear. The authors hypothesized that this protection is mediated at the level of alveolar tight junctions and investigated the possibility in a two-hit model of lung injury that mirrors human acute respiratory distress syndrome. Methods: Wild-type mice were treated with isoflurane 1 h after exposure to nebulized endotoxin (n = 8) or saline control (n = 9) and then allowed to recover for 24 h before mechanical ventilation (MV; tidal volume, 15 ml/kg, 2 h) producing ventilator-induced lung injury. Mouse lung epithelial cells were similarly treated with isoflurane 1 h after exposure to lipopolysaccharide. Cells were cyclically stretched the following day to mirror the MV protocol used in vivo. Results: Mice treated with isoflurane following exposure to inhaled endotoxin and before MV exhibited significantly less physiologic lung dysfunction. These effects appeared to be mediated by decreased vascular leak, but not altered inflammatory indices. Mouse lung epithelial cells treated with lipopolysaccharide and cyclic stretch and lungs harvested from mice after treatment with lipopolysaccharide and MV had decreased levels of a key tight junction protein (i.e., zona occludens 1) that was rescued by isoflurane treatment. Conclusions: Isoflurane rescued lung injury induced by a two-hit model of endotoxin exposure followed by MV by maintaining the integrity of the alveolar–capillary barrier possibly by modulating the expression of a key tight junction protein.

High mobility group (HMG) proteins are a family of architectural transcription factors, with HMGA1 playing a role in the regulation of genes involved in promoting systemic inflammatory responses. We speculated that blocking HMGA1-mediated pathways might improve outcomes from sepsis. To investigate HMGA1 further, we developed genetically modified mice expressing a dominant negative (dn) form of HMGA1 targeted to the vasculature. In dnHMGA1 transgenic (Tg) mice, endogenous HMGA1 is present, but its function is decreased due to the mutant transgene. These mice allowed us to specifically study the importance of HMGA1 not only during a purely pro-inflammatory insult of endotoxemia, but also during microbial sepsis induced by implantation of a bacterial-laden fibrin clot into the peritoneum. We found that the dnHMGA1 transgene was only present in Tg and not wild-type (WT) littermate mice, and the mutant transgene was able to interact with transcription factors (such as NF-κB), but was not able to bind DNA. Tg mice exhibited a blunted hypotensive response to endotoxemia, and less mortality in microbial sepsis. Moreover, Tg mice had a reduced inflammatory response during sepsis, with decreased macrophage and neutrophil infiltration into tissues, which was associated with reduced expression of monocyte chemotactic protein-1 and macrophage inflammatory protein-2. Collectively, these data suggest that targeted expression of a dnHMGA1 transgene is able to improve outcomes in models of endotoxin exposure and microbial sepsis, in part by modulating the immune response and suggest a novel modifiable pathway to target therapeutics in sepsis. High mobility group A1 is a modifiable pathway for therapeutics in sepsis, using a dominant negative approach to regulate the immune response.

This study was supported by MINECO (SAF2010-14916 and SAF2013-45800-R), FIS-RECAVA (RD06/0014/0006) and FISRIC (RD12/0042/0019) grants to C. V. A. M. and A. P. hold JAE-Predoc and FPI fellowships respectively. A. dlC. and T. G. hold RIC and R&C contracts respectively

Potassium channels modulate macrophage physiology. Blockade of voltage-dependent potassium channels (Kv) by specific antagonists decreases macrophage cytokine production and inhibits proliferation. In the presence of aspirin, acetylated cyclooxygenase-2 loses the activity required to synthesize PGs but maintains the oxygenase activity to produce 15R-HETE from arachidonate. This intermediate product is transformed via 5-LOX into epimeric lipoxins, termed 15-epi-lipoxins (15-epi-lipoxin A4 [e-LXA4]). Kv have been proposed as anti-inflammatory targets. Therefore, we studied the effects of e-LXA4 on signaling and on Kv and inward rectifier potassium channels (Kir) in mice bone marrow-derived macrophages (BMDM). Electrophysiological recordings were performed in these cells by the whole-cell patch-clamp technique. Treatment of BMDM with e-LXA4 inhibited LPS-dependent activation of NF-κB and IκB kinase ß activity, protected against LPS activation-dependent apoptosis, and enhanced the accumulation of the Nrf-2 transcription factor. Moreover, treatment of LPS-stimulated BMDM with e-LXA4 resulted in a rapid decrease of Kv currents, compatible with attenuation of the inflammatory response. Long-term treatment of LPS-stimulated BMDM with e-LXA4 significantly reverted LPS effects on Kv and Kir currents. Under these conditions, e-LXA4 decreased the calcium influx versus that observed in LPS-stimulated BMDM. These effects were partially mediated via the lipoxin receptor (ALX), because they were significantly reverted by a selective ALX receptor antagonist. We provide evidence for a new mechanism by which e-LXA4 contributes to inflammation resolution, consisting of the reversion of LPS effects on Kv and Kir currents in macrophages., This work was supported by Grants BFU2011-24760 (to L.B.), SAF2010-14916 (to C.V.), and PIB2010BZ-00540 (to L.B.) from Ministerio de Ciencia e Innovación; S2010/BMD2378 (to L.B.) from Comunidad de Madrid; and FIS-RECAVA RD06/0014/0025 and FIS-RIC RD12/0042/0019 (to L.B. and C.V.). Red de Investigación Cardiovascular and Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas are supported by the Instituto de Salud Carlos III. C.M. and M.P.-S. hold Formación de Personal Investigador fellowships, and A.M. holds a Junta para la Ampliación de Estudios Predoctoral fellowship.

Anesthetic management of patients presenting for urgent or emergent eye surgery after penetrating eye injury is challenging primarily because of the risk of extrusion of ocular contents if intraocular pressure becomes elevated. Additional concerns include risk of aspiration in patients with a full stomach, and the possibility of associated traumatic injuries (e.g., orbital or cranial trauma). A foreign body in the eye is the most common type of eye trauma, accounting for 35% of all eye injuries. Open wounds and contusions each account for about 25% of injuries, while the rest are burns. Nearly 35% of eye injuries occur in patients ≤17 years old. Although eye injury is not a significant cause of total blindness, it is the most common cause of monocular blindness.

Introduction: Hypothermia is perhaps the most frequent undesirable event in elective surgery. It is estimated that 1 h after surgery has initiated 70-90% of patients will experience hypothermia. In elective surgery, there are several factors leading to temperatures under 34 °C. Hypothermia may increases infections, bleeding and need for transfusion as well as the occurrence of an undesirable effect of discomfort and feared such as cold and postoperative shivering that can lead to cardiac complications due to increased of sympathetic influence. Objectives: Review the causes of these low temperatures within intraoperative elective surgery and check if the current alternatives to prevent hypothermia are effective. Methods: Review of non-systematic literature in PubMed and Medline was performed. Results: Hypothermia is the most common and least diagnosed undesirable event of patients undergoing surgery although it is easy to detect and preventive measures do not present major difficulties in their implementation. Conclusions: There are effective measures easy to set up, economical and effective to prevent hypothermia; the most important is the patient warm with hot air under pressure for 1 h and maintenance of air conditioning in the room above 22 °C. We just need to understand these measures and start to implement them. Resumen Introducción: La hipotermia es tal vez el evento indeseable mas frecuente en los pacientes que van a cirugía programada. Se considera que 1 hora después de iniciada la cirugía el 70 al 90% de los pacientes se encuentran hipotérmicos. En cirugía Electiva en pacientes sanos hay varios factores que llevan a que nuestros pacientes mantengan cifras de temperaturas de 34 °C e inclusive menores. El problema está en que la hipotermia aumenta las infecciones, el sangrado y la necesidad de trasfusión, la aparición de un efecto indeseable y temido por el paciente como es el frío y temblor postoperatorio que puede llevar a complicaciones cardiacas debido al aumento del influjo simpático. Objetivos: Revisarlas causas que llevan a estas bajas temperaturas intraoperatorias en cirugía programada y revisar si las opciones que tenemos hoy en día para prevenir la hipotermia pueden ser efectivas. Métodos: Se realizó una revisión de la literatura no sistemática en las bases de datos PubMed y Medline. Resultados: La hipotermia es el evento indeseable más frecuente y menos diagnosticado en el paciente que va a cirugía a pesar que es fácil de detectar y las medidas preventivas son relativamente fáciles de instaurar. Conclusiones: Hay medidas efectivas, fáciles de instaurar, económicas y efectivas para evitar la hipotermia y entre ellas la más importante es el precalentamiento del paciente con aire caliente a presión por 1 hora, el mantenimiento del aire acondicionado de la sala por encima de 22 grados centígrados. Solo necesitamos entender cuales son estas medidas e iniciar a ponerlas en practica.

Little is known about the mechanisms of persistent airflow obstruction that result from chronic occupational endotoxin exposure. We sought to analyze the inflammatory response underlying persistent airflow obstruction as a result of chronic occupational endotoxin exposure. We developed a murine model of daily inhaled endotoxin for periods of 5 days to 8 weeks. We analyzed physiologic lung dysfunction, lung histology, bronchoalveolar lavage fluid and total lung homogenate inflammatory cell and cytokine profiles, and pulmonary gene expression profiles. We observed an increase in airway hyperresponsiveness as a result of chronic endotoxin exposure. After 8 weeks, the mice exhibited an increase in bronchoalveolar lavage and lung neutrophils that correlated with an increase in proinflammatory cytokines. Detailed analyses of inflammatory cell subsets revealed an expansion of dendritic cells (DCs), and in particular, proinflammatory DCs, with a reduced percentage of macrophages. Gene expression profiling revealed the up-regulation of a panel of genes that was consistent with DC recruitment, and lung histology revealed an accumulation of DCs in inflammatory aggregates around the airways in 8-week-exposed animals. Repeated, low-dose LPS inhalation, which mirrors occupational exposure, resulted in airway hyperresponsiveness, associated with a failure to resolve the proinflammatory response, an inverted macrophage to DC ratio, and a significant rise in the inflammatory DC population. These findings point to a novel underlying mechanism of airflow obstruction as a result of occupational LPS exposure, and suggest molecular and cellular targets for therapeutic development.

Local anesthetics are useful probes of ion channel function and structure. Stereoselective interactions are especially interesting because they can reveal three-dimensional relationships between drugs and channels with otherwise identical biophysical and physicochemical properties. Furthermore, stereoselectivity suggests direct and specific receptor-mediated action, and identification of such stereospecific interactions may have important clinical consequences. The fact that drug targets are able to discriminate between the enantiomers present in a racemic drug is the consequence of the ordered asymmetric macromolecular units that form living cells. However, almost 25% of the drugs used in the clinical practice are racemic mixtures, and their individual enantiomers frequently differ in both their pharmacodynamic and pharmacokinetic profiles. Moreover, their effects can be similar to or different from the pharmacological effect of the drug and may contribute to the undesired effects of the drug. In other cases, the pharmacological effects induced by the two enantiomers on the molecular target are opposite. In the present manuscript, we will review the stereoselective effects of bupivacaine-like local anesthetics on cardiac sodium and potassium channels.

Kv1.5 channels are the primary channels contributing to the ultrarapid outward potassium current (IKur). The regulatory Kvβ1.3 subunit converts Kv1.5 channels from delayed rectifiers with a modest degree of slow inactivation to channels with both fast and slow inactivation components. Previous studies have shown that inhibition of PKC with calphostin C abolishes the fast inactivation induced by Kvβ1.3. In this study, we investigated the mechanisms underlying this phenomenon using electrophysiological, biochemical, and confocal microscopy approaches. To achieve this, we used HEK293 cells (which lack Kvβ subunits) transiently cotransfected with Kv1.5+Kvβ1.3 and also rat ventricular and atrial tissue to study native α-β subunit interactions. Immunocytochemistry assays demonstrated that these channel subunits colocalize in control conditions and after calphostin C treatment. Moreover, coimmunoprecipitation studies showed that Kv1.5 and Kvβ1.3 remain associated after PKC inhibition. After knocking down all PKC isoforms by siRNA or inhibiting PKC with calphostin C, Kvβ1.3-induced fast inactivation at +60 mV was abolished. However, depolarization to +100 mV revealed Kvβ1.3-induced inactivation, indicating that PKC inhibition causes a dramatic positive shift of the inactivation curve. Our results demonstrate that calphostin C-mediated abolishment of fast inactivation is not due to the dissociation of Kv1.5 and Kvβ1.3. Finally, immunoprecipitation and immunocytochemistry experiments revealed an association between Kv1.5, Kvβ1.3, the receptor for activated C kinase (RACK1), PKCβI, PKCβII, and PKCθ in HEK293 cells. A very similar Kv1.5 channelosome was found in rat ventricular tissue but not in atrial tissue.

et al., Neutral sphingomyelinase (nSMase)-derived ceramide has been proposed as a mediator of hypoxic pulmonary vasoconstriction (HPV), a specific response of the pulmonary circulation. Voltage-gated K+ (Kv) channels are modulated by numerous vasoactive factors, including hypoxia, and their inhibition has been involved in HPV. Herein, we have analyzed the effects of ceramide on Kv currents and contractility in rat pulmonary arteries (PA) and in mesenteric arteries (MA). The ceramide analog C6-ceramide inhibited Kv currents in PA smooth muscle cells (PASMC). Similar effects were obtained after the addition of bacterial sphingomyelinase (SMase), indicating a role for endogenous ceramide in Kv channel regulation. Kv current was reduced by stromatoxin and diphenylphosphine oxide-1 (DPO-1), selective inhibitors of Kv2.1 and Kv1.5 channels, respectively. The inhibitory effect of ceramide was still present in the presence of stromatoxin or DPO-1, suggesting that this sphingolipid inhibited both components of the native Kv current. Accordingly, ceramide inhibited Kv1.5 and Kv2.1 channels expressed in Ltk- cells. Ceramide-induced effects were reduced in human embryonic kidney 293 cells expressing Kv1.5 channels but not the regulatory subunit Kvβ2.1. The nSMase inhibitor GW4869 reduced the thromboxane-endoperoxide receptor agonist U46619-induced, but not endothelin-1-induced pulmonary vasoconstriction that was partly restored after addition of exogenous ceramide. The PKC-ζ pseudosubstrate inhibitor (PKCζ-PI) inhibited the Kv inhibitory and contractileé effects of ceramide. In MA ceramide had no effect on Kv currents and GW4869 did not affect U46619-induced contraction. The effects of SMase were also observed in human PA. These results suggest that ceramide represents a crucial signaling mediator in the pulmonary vasculature. © 2011 the American Physiological Society., This work was supported by Fundación Mutua Madrileña to A. Cogolludo, by the Spanish Ministerio de Ciencia e Innovación (Research Grants SAF2010-22066-C02-02 to A. Cogolludo; SAF2008-03948, AGL2007-66108 to F. Perez-Vizcaino; SAF2007-65868, SAF2010-14916, and FIS RD06/0014/0006 to C. Valenzuela; JAE-Doc contract to T. Gonzalez; RECAVA contract to M. David; SAF2008-03113 to J. Cortijo; Juan de la Cierva contract to L. Moreno and predoctoral FPI grant to C. Menendez) the Spanish Ministerio de Educación (predoctoral FPU grant to J. Moral-Sanz), and European Union FP7-PEOPLE (AOR-PERG05-GA-2009-249165) to F. Perez-Vizcaino and L. Moreno.

Celecoxib is a COX-2 inhibitor that has been related to an increased cardiovascular risk and that exerts several actions on different targets. The aim of this study was to analyze the effects of this drug on human cardiac voltage-gated potassium channels (Kv) involved on cardiac repolarization Kv1.5 (I(Kur)), Kv4.3+KChIP2 (I(to1)) and Kv7.1+KCNE1 (I(Ks)) and to compare with another COX-2 inhibitor, rofecoxib. Currents were recorded in transfected mammalian cells by whole-cell patch-clamp. Celecoxib blocked all the Kv channels analyzed and rofecoxib was always less potent, except on Kv4.3+KChIP2 channels. Kv1.5 block increased in the voltage range of channel activation, decreasing at potentials positive to 0 mV. The drug modified the activation curve of the channels that became biphasic. Block was frequency-dependent, increasing at fastest frequencies. Celecoxib effects were not altered by TEA(out) in R487Y mutant Kv1.5 channels but the kinetics of block were slower and the degree of block was smaller with TEA(in), indicating that celecoxib acts from the cytosolic side. We confirmed the blocking properties of celecoxib on native Kv currents from rat vascular cells, where Kv1.5 are the main contributors (IC(50)≈ 7 μM). Finally, we demonstrate that celecoxib prolongs the action potential duration in mouse cardiac myocytes and shortens it in guinea pig cardiac myocytes, suggesting that Kv block induced by celecoxib may be of clinical relevance.

Kv1.5 channels are homotetramers of alpha-pore subunits mainly present in human atrium and pulmonary vasculature. Thus, Kv1.5 is a pharmacological target for cardiovascular diseases. Kv beta 1.3 assemblies with Kv alpha 1.5 and modifies its gating and pharmacology. A further knowledge of alpha-beta interactions and pharmacology will lead a better design of new drugs.

High-mobility group box 1 (HMGB1) is a nuclear protein that has been found to be a critical mediator of lethality in endotoxemia and sepsis. During the systemic inflammatory response, circulating levels of HMGB1 are increased, but in a delayed fashion compared with early inflammatory mediators. To counteract the inflammatory response of endotoxemia, a secondary anti-inflammatory response ensues in an attempt to prevent inflammation-induced tissue injury. One such cytoprotective gene that is induced during endotoxemia is heme oxygenase (HO)-1. HO-1, and its products of heme metabolism, possess anti-inflammatory and antioxidant properties to counter the damaging effects of endotoxemia. In the present study, we wanted to determine whether tissue and circulating levels of HMGB1 are increased further in the absence of HO-1 during endotoxemia, and whether this increase may contribute to the pathobiology of endotoxemia. Lung inflammation, HMGB1 protein levels, and expression of HMGB1 in inflammatory cells were increased in HO-1(-/-) mice compared with HO-1+/+ mice. After the administration of LPS, tissue levels of HMGB1 were not increased further in HO-1(-/-) mice; however, circulating levels of HMGB1 were higher when compared with HO-1+/+ mice. HO-1(-/-) mice treated with a carbon monoxide-releasing molecule or biliverdin showed a reduction in plasma HMGB1, which was associated with a marked improvement in survival. HO-1(-/-) mice given HMGB1-neutralizing antibody showed improvement in survival compared with control antibody. These data suggest that exaggerated circulating levels of HMGB1 contribute to endotoxin-induced mortality in the absence of HO-1.

The inducible form of nitric oxide synthase (NOS2) plays an important role in sepsis incurred as a result of infection with Gram-negative bacteria that elaborate endotoxin. The HMGA1 (high-mobility group A1) architectural transcription factor facilitates NOS2 induction by binding a specific AT-rich Oct (octamer) sequence in the core NOS2 promoter via AT-hook motifs. The small-molecule MGB (minor-groove binder) netropsin selectively targets AT-rich DNA sequences and can interfere with transcription factor binding. We therefore hypothesized that netropsin would improve survival from murine endotoxaemia by attenuating NOS2 induction through interference with HMGA1 DNA binding to the core NOS2 promoter. Netropsin improved survival from endotoxaemia in wild-type mice, yet not in NOS2-deficient mice, supporting an important role for NOS2 in the beneficial effects of MGB administration. Netropsin significantly attenuated NOS2 promoter activity in macrophage transient transfection studies and the AT-rich HMGA1 DNA-binding site was critical for this effect. EMSAs (electrophoretic mobility-shift assays) demonstrated that netropsin interferes with HMGA1 NOS2 promoter binding and NMR spectroscopy was undertaken to characterize this disruption. Chemical shift perturbation analysis identified that netropsin effectively competes both HMGA1 DNA-binding AT-hooks from the AT-rich NOS2 promoter sequence. Furthermore, NOESY data identified direct molecular interactions between netropsin and A/T base pairs within the NOS2 promoter HMGA1-binding site. Finally, we determined a structure of the netropsin/NOS2 promoter Oct site complex from molecular modelling and dynamics calculations. These findings represent important steps toward refined structure-based ligand design of novel compounds for therapeutic benefit that can selectively target key regulatory regions within genes that are important for the development of critical illness.

Sepsis is characterized by a systemic response to severe infection. Although the inflammatory phase of sepsis helps eradicate the infection, it can have detrimental consequences if left unchecked. Therapy directed against inflammatory mediators of sepsis has shown little success and has the potential to impair innate antimicrobial defenses. Heme oxygenase-1 (HO-1) and the product of its enzymatic reaction, CO, have beneficial antiinflammatory properties, but little is known about their effects on microbial sepsis. Here, we have demonstrated that during microbial sepsis, HO-1–derived CO plays an important role in the antimicrobial process without inhibiting the inflammatory response. HO-1–deficient mice suffered exaggerated lethality from polymicrobial sepsis. Targeting HO-1 to SMCs and myofibroblasts of blood vessels and bowel ameliorated sepsis-induced death associated with Enterococcus faecalis, but not Escherichia coli, infection. The increase in HO-1 expression did not suppress circulating inflammatory cells or their accumulation at the site of injury but did enhance bacterial clearance by increasing phagocytosis and the endogenous antimicrobial response. Furthermore, injection of a CO-releasing molecule into WT mice increased phagocytosis and rescued HO-1–deficient mice from sepsis-induced lethality. These data advocate HO-1–derived CO as an important mediator of the host defense response to sepsis and suggest CO administration as a possible treatment for the disease.