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BACKGROUND: Spinal cord stimulation (SCS) has demonstrated multiple benefits in treating chronic pain and other clinical disorders related to sensorimotor dysfunctions. However, the underlying mechanisms are still not fully understood, including how electrode placement in relation to the spinal cord neuroanatomy influences epidural spinal recordings (ESRs). To characterize this relationship, this study utilized stimulation applied at various anatomical sections of the spinal column, including at levels of the intervertebral disc and regions correlating to the dorsal root entry zone. METHOD: Two electrode arrays were surgically implanted into the dorsal epidural space of the swine. The stimulation leads were positioned such that the caudal-most electrode contact was at the level of a thoracic intervertebral segment. Intraoperative cone beam computed tomography (CBCT) images were utilized to precisely determine the location of the epidural leads relative to the spinal column. High-resolution microCT imaging and 3D-model reconstructions of the explanted spinal cord illustrated precise positioning and dimensions of the epidural leads in relation to the surrounding neuroanatomy, including the spinal rootlets of the dorsal and ventral columns of the spinal cord. In a separate swine cohort, implanted epidural leads were used for SCS and recording evoked ESRs. RESULTS: Reconstructed 3D-models of the swine spinal cord with epidural lead implants demonstrated considerable distinctions in the dimensions of a single electrode contact on a standard industry epidural stimulation lead compared to dorsal rootlets at the dorsal root entry zone (DREZ). At the intervertebral segment, it was observed that a single electrode contact may cover 20-25% of the DREZ if positioned laterally. Electrode contacts were estimated to be ~0.75 mm from the margins of the DREZ when placed at the midline. Furthermore, ventral rootlets were observed to travel in proximity and parallel to dorsal rootlets at this level prior to separation into their respective sides of the spinal cord. Cathodic stimulation at the level of the intervertebral disc, compared to an 'off-disc' stimulation (7 mm rostral), demonstrated considerable variations in the features of recorded ESRs, such as amplitude and shape, and evoked unintended motor activation at lower stimulation thresholds. This substantial change may be due to the influence of nearby ventral roots. To further illustrate the influence of rootlet activation vs. dorsal column activation, the stimulation lead was displaced laterally at ~2.88 mm from the midline, resulting in variances in both evoked compound action potential (ECAP) components and electromyography (EMG) components in ESRs at lower stimulation thresholds. CONCLUSION: The results of this study suggest that the ECAP and EMG components of recorded ESRs can vary depending on small differences in the location of the stimulating electrodes within the spinal anatomy, such as at the level of the intervertebral segment. Furthermore, the effects of sub-centimeter lateral displacement of the stimulation lead from the midline, leading to significant changes in electrophysiological metrics. The results of this pilot study reveal the importance of the small displacement of the electrodes that can cause significant changes to evoked responses SCS. These results may provide further valuable insights into the underlying mechanisms and assist in optimizing future SCS-related applications.
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Parkinson's disease (PD) is marked by degeneration in the nigrostriatal dopaminergic pathway, affecting motor control via complex changes in the cortico-basal ganglia-thalamic motor network, including the primary motor cortex (M1). The modulation of M1 neuronal activity by dopaminergic inputs, particularly from the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc), plays a crucial role in PD pathophysiology. This study investigates how nigrostriatal dopaminergic degeneration influences M1 neuronal activity in rats using in vivo calcium imaging. Histological analysis confirmed dopaminergic lesion severity, with high lesion level rats showing significant motor deficits. Levodopa treatment improved fine motor abilities, particularly in high lesion level rats. Analysis of M1 calcium signals based on dopaminergic lesion severity revealed distinct M1 activity patterns. Animals with low dopaminergic lesion showed increased calcium events, while high lesion level rats exhibited decreased activity, partially restored by levodopa. These findings suggest that M1 activity is more sensitive to transient fluctuations in dopaminergic transmission, rather than to chronic high or low dopaminergic signaling. This study underscores the complex interplay between dopaminergic signaling and M1 neuronal activity in PD symptoms development. Further research integrating behavioral and calcium imaging data can elucidate mechanisms underlying motor deficits and therapeutic responses in PD.
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BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a well-established treatment for the motor symptoms of Parkinson's disease (PD). While PD is primarily characterized by motor symptoms such as tremor, rigidity, and bradykinesia, it also involves a range of non-motor symptoms, and anxiety is one of the most common. The relationship between PD and anxiety is complex and can be a result of both pathological neural changes and the psychological and emotional impacts of living with a chronic progressive condition. Managing anxiety in PD is critical for improving the patients' quality of life. However, patients undergoing STN DBS can occasionally experience increased anxiety. METHODS: This study investigates changes in risk-avoidant behavior following STN DBS in a pre-motor animal model of PD under chronic and acute unilateral high frequency stimulation. RESULTS: No significant changes in risk-avoidant behaviors were observed in rats who underwent STN DBS compared with sham stimulation controls. Chronic stimulation prevented sensitization in the elevated zero maze. CONCLUSIONS: These results suggest that unilateral stimulation of the STN may have minimal effects on risk-avoidant behaviors in PD. However, additional research is required to fully understand the mechanisms responsible for changes in anxiety during STN DBS for PD.
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Estimulación Encefálica Profunda , Modelos Animales de Enfermedad , Oxidopamina , Núcleo Subtalámico , Animales , Oxidopamina/farmacología , Masculino , Conducta Animal/fisiología , Trastornos Parkinsonianos/terapia , Trastornos Parkinsonianos/fisiopatología , Ansiedad/etiología , Ansiedad/fisiopatología , Ratas , Ratas Sprague-Dawley , Reacción de Prevención/fisiología , Enfermedad de Parkinson/terapia , Enfermedad de Parkinson/fisiopatologíaRESUMEN
BACKGROUND: The enhanced view totally extraperitoneal (eTEP) approach is becoming increasingly more widely accepted as a promising technique in the treatment of ventral hernia. However, evidence is still lacking regarding the perioperative, postoperative and long-term outcomes of this technique. The aim of this meta-analysis is to summarize the current available evidence regarding the perioperative and short-term outcomes of ventral hernia repair using eTEP. STUDY DESIGN: A systematic search was performed of PubMed, EMBASE, Cochrane Library and Web of Science electronic databases to identify studies on the laparoscopic or robotic-enhanced view totally extraperitoneal (eTEP) approach for the treatment of ventral hernia. A pooled meta-analysis was performed. The primary end point was focused on short-term outcomes regarding perioperative characteristics and postoperative parameters. RESULTS: A total of 13 studies were identified involving 918 patients. Minimally invasive eTEP resulted in a rate of surgical site infection of 0% [95% CI 0.0-1.0%], a rate of seroma of 5% [95% CI 2.0-8.0%] and a rate of major complications (Clavien-Dindo III-IV) of 1% [95% CI 0.0-3.0%]. The rate of intraoperative complications was 2% [95% CI 0.0-4.0%] with a conversion rate of 1.0% [95% CI 0.0-3.0%]. Mean hospital length of stay was 1.77 days [95% CI 1.21-2.24]. After a median follow-up of 6.6 months (1-24), the rate of recurrence was 1% [95% CI 0.0-1.0%]. CONCLUSION: Minimally invasive eTEP is a safe and effective approach for ventral hernia repair, with low reported intraoperative complications and good outcomes.
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Hernia Ventral , Hernia Incisional , Laparoscopía , Humanos , Herniorrafia/efectos adversos , Herniorrafia/métodos , Mallas Quirúrgicas , Hernia Ventral/cirugía , Laparoscopía/efectos adversos , Laparoscopía/métodos , Complicaciones Intraoperatorias , Hernia Incisional/cirugíaRESUMEN
Fast Scan Cyclic Voltammetry (FSCV) has been used for decades as a neurochemical tool for in vivo detection of phasic changes in electroactive neurotransmitters in animal models. Recently, multiple research groups have initiated human neurochemical studies using FSCV or demonstrated interest in bringing FSCV into clinical use. However, there remain technical challenges that limit clinical implementation of FSCV by creating barriers to appropriate scientific rigor and patient safety. In order to progress with clinical FSCV, these limitations must be first addressed through (1) appropriate pre-clinical studies to ensure accurate measurement of neurotransmitters and (2) the application of a risk management framework to assess patient safety. The intent of this work is to bring awareness of the current issues associated with FSCV to the scientific, engineering, and clinical communities and encourage them to seek solutions or alternatives that ensure data accuracy, rigor and reproducibility, and patient safety.
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Modern techniques for estimating basal levels of electroactive neurotransmitters rely on the measurement of oxidative charges. This requires time integration of oxidation currents at certain intervals. Unfortunately, the selection of integration intervals relies on ad-hoc visual identification of peaks on the oxidation currents, which introduces sources of error and precludes the development of automated procedures necessary for analysis and quantification of neurotransmitter levels in large data sets. In an effort to improve charge quantification techniques, here we present novel methods for automatic selection of integration boundaries. Our results show that these methods allow quantification of oxidation reactions both in vitro and in vivo and of multiple analytes in vitro.
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Dopamina/aislamiento & purificación , Técnicas Electroquímicas , Neurotransmisores/aislamiento & purificación , Serotonina/aislamiento & purificación , Adenosina/metabolismo , Animales , Dopamina/metabolismo , Epinefrina/metabolismo , Humanos , Microelectrodos , Neuroquímica , Neurotransmisores/metabolismo , Norepinefrina/metabolismo , Oxidación-Reducción , Ratas , Serotonina/metabolismoRESUMEN
BACKGROUND: Adrenomedullin (AM) is a vasoactive peptide mostly secreted by endothelial cells with an important role in preserving endothelial integrity. The relationship between AM and hereditary hemorrhagic telangiectasia (HHT) is unknown. We aimed to compare the serum levels and tissue expression of AM between HHT patients and controls. METHODS: Serum AM levels were measured by radioimmunoassay and compared between control and HHT groups. AM levels were also compared among HHT subgroups according to clinical characteristics. The single nucleotide polymorphism (SNP) rs4910118 was assessed by restriction analysis and sequencing. AM immunohistochemistry was performed on biopsies of cutaneous telangiectasia from eight HHT patients and on the healthy skin from five patients in the control group. RESULTS: Forty-five HHT patients and 50 healthy controls were included, mean age (SD) was 50.7 (14.9) years and 46.4 (9.9) years (p = 0.102), respectively. HHT patients were mostly female (60% vs 38%, p = 0.032). Median [Q1-Q3] serum AM levels were 68.3 [58.1-80.6] pg/mL in the HHT group and 47.7 [43.2-53.8] pg/mL in controls (p<0.001), with an optimal AM cut-off according to Youden's J statistic of 55.32 pg/mL (J:0.729). Serum AM levels were similar in the HHT subgroups. No patient with HHT had the SNP rs4910118. AM immunoreactivity was found with high intensity in the abnormal blood vessels of HHT biopsies. CONCLUSIONS: We detected higher AM serum levels and tissue expression in patients with HHT than in healthy controls. The role of AM in HHT, and whether AM may constitute a novel biomarker and therapeutic target, needs further investigation.
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Telangiectasia Hemorrágica Hereditaria , Adrenomedulina/genética , Biomarcadores , Células Endoteliales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Telangiectasia Hemorrágica Hereditaria/genéticaRESUMEN
Tactics to increase the number of underrepresented (UR) students in biomedical research PhD training programs have not yet translated to UR faculty numbers that reflect the diversity of the United States. Continued interventions are required to build skills beyond those that result in placement into a PhD program. We hypothesize that successful interventions must build skills that give UR students foundations for confident self-efficacy in leadership. We seek interventions that allow UR students to envision themselves as successful faculty. We posit that development of such skills is difficult in the classroom or laboratory alone. Therefore, novel interventions are required. As part of the NIH-funded Post-baccalaureate Research Education Program (PREP) and Initiative for Maximizing Student Development (IMSD) at the Mayo Clinic Graduate School of Biomedical Sciences, we designed and implemented a unique intervention to support development of student leadership skills: a biannual student-organized and student-led national research conference titled "Scientific Innovation Through Diverse Perspectives" (SITDP). This initiative is based on the concept that students who actively live out realistic roles as scientific leaders will be encouraged to persist to scientific leadership as faculty. Here we describe the motivation for, design of, and outcomes from, the first three pilot conferences of this series. We further discuss approaches needed to rigorously evaluate the effectiveness of such interventions in the future.
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Astrocytes are actively involved in a neuroprotective role in the brain, which includes scavenging reactive oxygen species to minimize tissue damage. They also modulate neuroinflammation and reactive gliosis prevalent in several brain disorders like epilepsy, Alzheimer's, and Parkinson's disease. In animal models, targeted manipulation of astrocytic function via modulation of their calcium (Ca2+ ) oscillations by incorporating light-sensitive cation channels like Channelrhodopsin-2 (ChR2) offers a promising avenue in influencing the long-term progression of these disorders. However, using adult animals for Ca2+ imaging poses major challenges, including accelerated deterioration of in situ slice health and age- related changes. Additionally, optogenetic preparations necessitate usage of a red-shifted Ca2+ indicator like Rhod-2 AM to avoid overlapping light issues between ChR2 and the Ca2+ indicator during simultaneous optogenetic stimulation and imaging. In this article, we provide an experimental setting that uses live adult murine brain slices (2-5 months) from a knock-in model expressing Channelrhodopsin-2 (ChR2(C128S)) in cortical astrocytes, loaded with Rhod-2 AM to elicit robust Ca2+ response to light stimulation. We have developed and standardized a protocol for brain extraction, sectioning, Rhod-2 AM loading, maintenance of slice health, and Ca2+ imaging during light stimulation. This has been successfully applied to optogenetically control adult cortical astrocytes, which exhibit synchronous patterns of Ca2+ activity upon light stimulation, drastically different from resting spontaneous activity. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Experimental preparation, setup, slice preparation and Rhod-2 AM staining Basic Protocol 2: Image acquisition and analysis.
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Astrocitos/fisiología , Señalización del Calcio/fisiología , Corteza Cerebral/citología , Corteza Cerebral/fisiología , Optogenética/métodos , Imagen de Lapso de Tiempo/métodos , Factores de Edad , Animales , Astrocitos/química , Corteza Cerebral/química , Ratones , Técnicas de Cultivo de Órganos/métodosRESUMEN
Scientific societies aiming to foster inclusion of scientists from underrepresented (UR) backgrounds among their membership often delegate primary responsibility for this goal to a diversity-focused committee. The National Science Foundation has funded the creation of the Alliance to Catalyze Change for Equity in STEM Success (ACCESS), a meta-organization bringing together representatives from several such STEM society committees to serve as a hub for a growing community of practice. Our goal is to coordinate efforts to advance inclusive practices by sharing experiences and making synergistic discoveries about what works. ACCESS has analyzed the approaches by which member societies have sought to ensure inclusivity through selection of annual meeting speakers. Here we discuss how inclusive speaker selection fosters better scientific environments for all and identify challenges and promising practices for societies striving to maximize inclusivity of speakers in their scientific programming.
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Diversidad Cultural , Investigadores/ética , Sociedades Científicas/tendencias , Demografía , Humanos , Sociedades Científicas/ética , Habla/éticaRESUMEN
After decades of study in humans and animal models, there remains a lack of consensus regarding how the action of electrical stimulation on neuronal and non-neuronal elements - e.g. neuropil, cell bodies, glial cells, etc. - leads to the therapeutic effects of neuromodulation therapies. To further our understanding of neuromodulation therapies, there is a critical need for novel methodological approaches using state-of-the-art neuroscience tools to study neuromodulation therapy in preclinical models of disease. In this manuscript we outline one such approach combining chronic behaving single-photon microendoscope recordings in a pathological mouse model with electrical stimulation of a common deep brain stimulation (DBS) target. We describe in detail the steps necessary to realize this approach, as well as discuss key considerations for extending this experimental paradigm to other DBS targets for different therapeutic indications. Additionally, we make recommendations from our experience on implementing and validating the required combination of procedures that includes: the induction of a pathological model (6-OHDA model of Parkinson's disease) through an injection procedure, the injection of the viral vector to induce GCaMP expression, the implantation of the GRIN lens and stimulation electrode, and the installation of a baseplate for mounting the microendoscope. We proactively identify unique data analysis confounds occurring due to the combination of electrical stimulation and optical recordings and outline an approach to address these confounds. In order to validate the technical feasibility of this unique combination of experimental methods, we present data to demonstrate that 1) despite the complex multifaceted surgical procedures, chronic optical recordings of hundreds of cells combined with stimulation is achievable over week long periods 2) this approach enables measurement of differences in DBS evoked neural activity between anesthetized and awake conditions and 3) this combination of techniques can be used to measure electrical stimulation induced changes in neural activity during behavior in a pathological mouse model. These findings are presented to underscore the feasibility and potential utility of minimally constrained optical recordings to elucidate the mechanisms of DBS therapies in animal models of disease.
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BACKGROUND: Weight loss after bariatric surgery varies among patients. Patients who do not complete long-term follow-up are considered to loose less weight than those with regular follow-up visits. OBJECTIVE: To evaluate the influence of patients' follow-up compliance on long-term excess weight loss (%EWL) and total weight loss (%TWL) after bariatric surgery, comparing results between gastric bypass (GB) and sleeve gastrectomy (SG). METHODS: Patients with up to 5 years of follow-up data after bariatric surgery were included in this retrospective analysis. Patients were divided in 2 groups: those in group 1 who had attended every scheduled postoperative appointment and those in group 2 who had been lost to follow-up before 1 year and were later contacted by telephone. %EWL and %TWL were compared to determine the possible relationship between type of surgery and regularity of the follow-up. RESULTS: A total of 385 patients were included. A significant difference in EWL was observed at 5 years in the SG group (78% for group 1 versus 39% for group 2; p = 0.02) and GB group (75% for group 1 versus 62% for group 2; p = 0.01). No significant differences between surgeries were found when comparing long-term EWL in group 1 patients 77% for SG versus 75% for GB. For group 2 patients, GB achieved greater EWL than SG; p = 0.005. %TWL patients in group 2 showed significant differences in all periods of study (p < 0.05). CONCLUSION: Bariatric surgery patients who attended all scheduled follow-up appointments experienced significantly greater long-term EWL and TWL than those who did not. GB has apparent increased benefits for weight loss in long-term follow-up when compared with SG for patients who did not attend long-term follow-up. Therefore, continued long-term follow-up of bariatric patients should be encouraged to increase postoperative weight loss results.
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Cirugía Bariátrica , Derivación Gástrica , Obesidad Mórbida , Estudios de Seguimiento , Gastrectomía , Humanos , Obesidad Mórbida/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Pérdida de PesoRESUMEN
Diversity-focused committees continue to play essential roles in the efforts of professional scientific societies to foster inclusion and facilitate the professional development of underrepresented minority (URM) young scientists in their respective scientific disciplines. Until recently, the efforts of these committees have remained independent and disconnected from one another. Funding from the National Science Foundation has allowed several of these committees to come together and form the Alliance to Catalyze Change for Equity in STEM Success, herein referred to as ACCESS. The overall goal of this meta-organization is to create a community in which diversity-focused committees can interact, synergize, share their collective experiences, and have a unified voice on behalf of URM trainees in science, technology, engineering, and mathematics disciplines. In this Essay, we compare and contrast the broad approaches that scientific societies in ACCESS use to implement and assess their travel award programs for URM trainees. We also report a set of recommendations, including both short- and long-term outcomes assessment in populations of interest and specialized programmatic activities coupled to travel award programs.
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Distinciones y Premios , Sociedades Científicas , Ingeniería , Ambiente , ViajeRESUMEN
Engineering technology plays a pivotal role in the delivery of health care in under-resourced countries by providing an infrastructure to improve patient outcomes. However, sustainability of these technologies is difficult in these settings oftentimes due to limited resources or training. The framework presented in this editorial focuses on establishing medical and laboratory equipment sustainability in developing countries and is comprised of four steps: 1) establishing reliable in-country relationships with stakeholders, 2) identifying needs for sustainable solutions locally, 3) exploring potential solutions and assessing their effort-to-impact ratios, and 4) working with strategic partners to implement solutions with clear performance metrics. By focusing on the sustainability of donated equipment instead of the equipment itself, this method presented distinguishes itself from other philanthropic endeavors in the field by seeking to establish preventive maintenance habits that can impact clinical outcomes of a community long term. Application of this methodology is reported in the Original Research Article "A Low-Cost Humidity Control System to Protect Microscopes in a Tropical Climate" by Asp et. al.
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Países en Desarrollo , Equipos y Suministros , Recursos en Salud , Evaluación de Programas y Proyectos de Salud , Utilización de Equipos y Suministros , Humanos , Mantenimiento , Evaluación de Necesidades , Organizaciones sin Fines de Lucro , Participación de los Interesados , EnseñanzaRESUMEN
BACKGROUND: Gender differences in organ involvement and clinical severity have been poorly described in hereditary hemorrhagic telangiectasia (HHT). The aim of this study was to describe differences in the severity of HHT manifestations according to gender. METHODS: Severity was measured according to Epistaxis Severity Score (ESS), Simple Clinical Scoring Index for hepatic involvement, a general HHT-score, needing for invasive treatment (pulmonary or brain arteriovenous malformations -AVMs- embolization, liver transplantation or Young's surgery) or the presence of adverse outcomes (severe anemia, emergency department -ED- or hospital admissions and mortality). RESULTS: One hundred forty-two (58.7%) women and 100 (41.3%) men were included with a mean age of 48.9 ± 16.6 and 49 ± 16.5 years, respectively. Women presented hepatic manifestations (7.1% vs 0%) and hepatic involvement (59.8% vs 47%), hepatic AVMs (28.2% vs 13%) and bile duct dilatation (4.9% vs 0%) at abdominal CT, and pulmonary AVMs at thoracic CT (35.2% vs 23%) more often than men. The Simple Clinical Scoring Index was higher in women (3.38 ± 1.2 vs 2.03 ± 1.2), and more men were considered at low risk of harboring clinically significant liver disease than women (61% vs 25.3%). These differences were mantained when considering HHT1 and HHT2 patients separetely. Duodenal telangiectasia were more frequent in men than women (21% vs 9.8%). Invasive treatments were more frequently needed in women (28.2% vs 16%) but men needed attention at the ED more often than women (48% vs 28.2%), with no differences in ESS, HHT-score, anemia hospital admissions or mortality. CONCLUSIONS: HHT women showed more severe hepatic involvement than men, also among HHT1 and HHT2 patients. Women had higher prevalence of pulmonary AVMs and needed invasive procedures more frequently, while men needed attention at the ED more often. These data might help physicians to individualize HHT patients follow-up.
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Malformaciones Arteriovenosas , Hepatopatías , Telangiectasia Hemorrágica Hereditaria , Adulto , Anciano , Epistaxis , Femenino , Humanos , Masculino , Persona de Mediana Edad , Caracteres SexualesRESUMEN
Introduction: A clean and functional microscope is necessary for accurate diagnosis of infectious diseases. In tropical climates, high humidity levels and improper storage conditions allow for the accumulation of debris and fungus on the optical components of diagnostic equipment, such as microscopes. Objective: Our objective was to develop and implement a low-cost, sustainable, easy to manage, low-maintenance, passive humidity control chamber to both reduce debris accumulation and microbial growth onto the optical components of microscopes. Methods: Constructed from easily-sourced and locally available materials, the cost of each humidity control chamber is approximately $2.35 USD. Relative humidity levels were recorded every 30 minutes over a period of 10 weeks from two chambers deployed at the Belize Vector and Ecology Center and the University of Belize. Results: The humidity control chamber deployed at the University of Belize maintained internal relative humidity at an average of 35.3% (SD = 4.2%) over 10 weeks, while the average external relative humidity was 86.4% (SD = 12.4%). The humidity control chamber deployed at the Belize Vector and Ecology Center effectively maintained internal relative humidity to an average of 54.5% (SD = 9.4%) over 10 weeks, while the average external relative humidity was 86.9% (SD = 12.9%). Conclusions: Control of relative humidity is paramount for the sustainability of medical equipment in tropical climates. The humidity control chambers reduced relative humidity to levels that were not conducive for fungal growth while reducing microscope contamination from external sources. This will likely extend the service life of the microscopes while taking advantage of low-cost, locally sourced components.
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Humedad/prevención & control , Higroscópicos , Microscopía/instrumentación , Clima Tropical , Belice , Costos y Análisis de Costo , Contaminación de Equipos/economía , Contaminación de Equipos/prevención & control , Equipos y Suministros , Hongos/crecimiento & desarrollo , Humanos , Humedad/efectos adversos , Higroscópicos/economía , Microscopía/economía , Dióxido de Silicio/economíaRESUMEN
Objective: To assess the correlation between left ventricular outflow tract velocity time integral (LVOT VTI) and stroke volume index (SVI) calculated by thermodilution methods in ventilated critically ill patients. Design: A prospective, descriptive, multicenter study was performed. Setting: Five intensive care units from university hospitals. Patients: Patients older than 17 years needing mechanical ventilation and invasive hemodynamic monitoring were included. Interventions: LVOT VTI was measured by pulsatile Doppler echocardiography. Calculations of SVI were performed through a floating pulmonary artery catheter (PAC) or a Pulse index Contour Cardiac Output (PiCCO(R)) thermodilution methods. Main variables: The relation between LVOT VTI and SVI was tested by linear regression analysis. Results: One hundred and fifty-six paired measurements were compared. Mean LVOT VTI was 20.83±4.86cm and mean SVI was 41.55±9.55mL/m2. Pearson correlation index for these variables was r=0.644, p<0.001; ICC was 0.52 (CI 95% 0.4-0.63). When maximum LVOT VTI was correlated with SVI, Pearson correlation index was r=0.62, p<0.001. Correlation worsened for extreme values, especially for those with higher LVOT VTI. Conclusions: LVOT VTI could be a complementary hemodynamic evaluation in selected patients, but does not eliminate the need for invasive monitoring at the present time. The weak correlation between LVOT VTI and invasive monitoring deserves additional assessment to identify the factors affecting this disagreement
Objetivo: Evaluar la correlación entre la integral velocidad tiempo del tracto de salida del ventrículo izquierdo (IVT TSVI) y el índice volumen sistólico (IVS) calculado por métodos de termodilución en pacientes ventilados críticamente enfermos. Diseño: Se realizó un estudio prospectivo, descriptivo y multicéntrico. Ámbito: Cinco unidades de cuidados intensivos de hospitales universitarios. Pacientes: Se incluyeron pacientes mayores de 17 años que necesitaron ventilación mecánica y monitorización hemodinámica invasiva. Intervenciones: La IVT TSVI se midió mediante Doppler pulsátil. Los cálculos de SVI se realizaron a través de un catéter de arteria pulmonar (CAP) o un método de Pulse index Contour Cardiac Output (PiCCO(R)), con métodos de termodilución. Variables principales: La relación entre IVT TSVI e IVS se evaluó mediante análisis de regresión lineal. Resultados: Se compararon 156 mediciones pareadas. La IVT TSVI media fue de 20,83±4,86cm y la media de IVS fue de 41,55±9,55ml/m2. El índice de correlación de Pearson para estas variables fue r=0,644, p<0,001; ICC fue 0,52 (IC 95%: 0,4-0,63). Cuando la IVT TSVI máxima se correlacionó con el IVS, el índice de correlación de Pearson fue r=0,62, p<0,001. La correlación empeoró para los valores extremos, especialmente para aquellos con mayor IVT TSVI. Conclusiones: La IVT TSVI podría ser una evaluación hemodinámica complementaria en pacientes seleccionados, pero no elimina la necesidad de un control invasivo en la actualidad. La débil correlación entre la IVT TSVI y la monitorización invasiva requiere estudios adicionales para identificar los factores que afectan a este desacuerdo