Blood Oxygen Research Articles

Modeling refined differences of cortical folding patterns via spatial, morphological, and temporal fusion representations.

The gyrus, a pivotal cortical folding pattern, is essential for integrating brain structure-function. This study focuses on 2-Hinge and 3-Hinge folds, characterized by the gyral convergence from various directions. Existing voxel-level studies may not adequately capture the precise spatial relationships within cortical folding patterns, especially when relying solely on local cortical characteristics due to their variable shapes and homogeneous frequency-specific features. To overcome these challenges, we introduced a novel model that combines spatial distribution, morphological structure, and functional magnetic resonance imaging data. We utilized spatio-morphological residual representations to enhance and extract subtle variations in cortical spatial distribution and morphological structure during blood oxygenation, integrating these with functional magnetic resonance imaging embeddings using self-attention for spatio-morphological-temporal representations. Testing these representations for identifying cortical folding patterns, including sulci, gyri, 2-Hinge, and 2-Hinge folds, and evaluating the impact of phenotypic data (e.g. stimulus) on recognition, our experimental results demonstrate the model's superior performance, revealing significant differences in cortical folding patterns under various stimulus. These differences are also evident in the characteristics of sulci and gyri folds between genders, with 3-Hinge showing more variations. Our findings indicate that our representations of cortical folding patterns could serve as biomarkers for understanding brain structure-function correlations.

An assessment of cardiac nurses' knowledge and practices regarding patient safety after cardiac catheterization

Cardiac catheterization is a medical procedure that helps doctors examine the heart and its blood vessels in detail. It involves inserting catheters (thin tubes) into a blood vessel in the arm or leg and guiding them to the heart with the help of X-ray images. This process allows for the collection of data on blood flow, pressure, and oxygen levels in the heart, as well as taking samples and imaging the heart's arteries and chambers. Ensuring patient safety, which means preventing harm during healthcare, is crucial, especially after this procedure. The team performing cardiac catheterization must prioritize safety and quality care to avoid complications. This study, the first of its kind in the Northern Region of Saudi Arabia, aims to evaluate the knowledge and practices of cardiac nurses regarding patient safety after cardiac catheterization. It employs a descriptive, correlational, cross-sectional design and analyzes data using frequency and percentages. Conducted from July to September 2023 at a Cardiac Center in Hail, Saudi Arabia, it involves nurses with varying levels of education and experience in cardiac care. The research tools include a questionnaire on potential complications post-catheterization and an observation tool for nursing care. The findings indicate that experience affects knowledge levels, with nurses having over five years of experience showing higher knowledge. The study also finds that most nurses have moderate to adequate knowledge about patient safety post-catheterization, but there's room for improvement. Compared to similar studies, this research underscores the importance of experienced nursing care in preventing complications. It suggests the need for enhanced training and education focusing on care after cardiac catheterization to improve patient outcomes.

Therapeutic efficacy of adrenergic agents on systemic and spinal hemodynamics in an acute cervical spinal cord injury rodent model

BACKGROUNDCervical spinal cord injury usually results in cardiorespiratory dysfunctions due to interruptions of the bulbospinal pathways innervating the cervical phrenic motoneurons and thoracic sympathetic preganglionic neurons. PURPOSEThe present study aimed to evaluate the therapeutic effects of adrenergic agents on systemic and spinal hemodynamics during acute cervical spinal cord injury. STUDY DESIGNIn vivo animal study. METHODSThe cardiorespiratory function and spinal cord blood flow and oxygenation level were monitored in response to cervical spinal cord contusion and intravenous infusion of three types of adrenergic agents (phenylephrine, dobutamine, and norepinephrine). RESULTSCervical spinal cord contusion resulted in immediate reduction of respiratory airflow, arterial blood pressure, and spinal cord blood flow. The arterial blood pressure and spinal cord blood flow remained lower than the pre-injury value in contused animals infused with saline at 60 min post-injury. Infusion of phenylephrine (500, 1000, and 2000 μg/kg) and norepinephrine (125, 250, and 500 μg/kg) significantly increased the arterial blood pressure, while only norepinephrine augmented the spinal cord blood flow. Conversely, dobutamine (1000 and 2000 μg/kg) reduced both arterial blood pressure and spinal cord blood flow. Notably, administration of adrenergic agents tended to increase spinal cord hemorrhage in contused animals. CONCLUSIONSInfusion of norepinephrine can effectively maintain the blood pressure and improve spinal cord blood flow during acute spinal cord injury. CLINICAL SIGNIFICANCENorepinephrine may be a superior medicine for hemodynamic management; however, the potential hemorrhage should be considered when utilizing the vasopressor to regulate systemic and spinal hemodynamics at the acute injured stage.

Bilateral Carotid Calcification Correlates with Regional Cerebral Glucose Metabolism: Insights from PET/CT Imaging of Patients with Cardiovascular Risk Factors

Bilateral Carotid Calcification Correlates with Regional Cerebral Glucose Metabolism: Insights from PET/CT Imaging of Patients with Cardiovascular Risk Factors

Physiologically based modeling reveals different risk of respiratory depression after fentanyl overdose between adults and children.

Despite a rapid increase in pediatric mortality rate from prescription and illicit opioids, there is limited research on the dose-dependent impact of opioids on respiratory depression in children, the leading cause of opioid-associated death. In this article, we extend a previously developed translational model to cover pediatric populations by incorporating age-dependent pharmacokinetic, pharmacodynamic, and physiological changes compared to adults. Our model reproduced previous perioperative clinical findings that adults and children have similar risk of respiratory depression at the same plasma fentanyl concentration when specific endpoints (minute ventilation, CO2 tension in the blood) were used. However, our model points to a potential caveat that, in a perioperative setting, routine use of mechanical ventilation and supplemental oxygen maintained the blood and tissue oxygen partial pressures in patients and prevented the use of oxygen-related endpoints to evaluate the consequences of respiratory depression. In a community setting when such oxygenation procedures are not immediately available, our model suggests that the higher oxygen demand and reduced cerebrovascular reactivity could make children more susceptible to severe hypoxemia and brain hypoxia, even with the same plasma fentanyl concentration as adults. Our work indicates that when developing intervention strategies to protect children from opioid overdose in a community setting, these pediatric-specific factors may need to be considered.

Incidence of dreaming during ciprofol anesthesia for painless gastroscopy.

Dreaming is often reported by patients who undergo propofol-based sedation, but there have not been any studies to date focused on the incidence of dreaming and factors associated therewith following the administration of ciprofol anesthesia in patients undergoing painless gastroscopy. The present study was thus developed with the goal of assessing the incidence of dreaming. In total, this study enrolled 200 patients undergoing painless gastroscopy. During the procedure, patients' electroencephalographic Bispectral Index (BIS), blood pressure (BP), heart rate (HR), blood oxygen saturation (SpO<inf>2</inf>), and PETCO<inf>2</inf> were monitored. When their MOAA/S score reached five after the procedure, patients were administered questionnaires including the Brice questionnaire and a five-point Likert Scale, and the content of any recalled dreams was also recorded. Overall, 27.5% of the participants in this study reported dreaming during the procedure, with most having experienced simple, pleasant dreams about everyday life. Identified predictors of dreaming during painless gastroscopy included lower ASA grade, preoperative knowledge of painless examination, a higher frequency of dreams in the month before the procedure, poor sleep quality during the month before the procedure, and shorter awakening time. Dreamers showed significantly lower BIS values at 2 min after endoscope insertion and following endoscope removal, and also showed lower minimum BIS values compared with non-dreamers. The postoperative dream recall incidence in this study was 27.5% among patients undergoing painless gastroscopy under ciprofol sedation anesthesia.

Folic Acid Functionalized AQ4N/Gd@PDA Nanoplatform with Real-Time Monitoring of Hypoxia Relief and Enhanced Synergistic Chemo/Photothermal Therapy in Glioma.

Hypoxia is often associated with glioma chemoresistance, and alleviating hypoxia is also crucial for improving treatment efficacy. However, although there are already some methods that can improve efficacy by alleviating hypoxia, real-time monitoring that can truly achieve hypoxia relief and efficacy feedback still needs to be explored. AQ4N/Gd@PDA-FA nanoparticles (AGPF NPs) were synthesized using a one-pot method and were characterized. The effects of AGPF NPs on cell viability, cellular uptake, and apoptosis were investigated using the U87 cell line. Moreover, the effectiveness of AGPF NPs in alleviating hypoxia was explored in tumor-bearing mice through photoacoustic imaging. In addition, the diagnosis and treatment effect of AGPF NPs were evaluated by magnetic resonance imaging (MRI) and bioluminescent imaging (BLI) on orthotopic glioma mice respectively. In vitro experiments showed that AGPF NPs had good dispersion, stability, and controlled release. AGPF NPs were internalized by cells through endocytosis, and could significantly reduce the survival rate of U87 cells and increase apoptosis under irradiation. In addition, we monitored blood oxygen saturation at the tumor site in real-time through photoacoustic imaging (PAI), and the results showed that synergistic mild-photothermal therapy/chemotherapy effectively alleviated tumor hypoxia. Finally, in vivo anti-tumor experiments have shown that synergistic therapy can effectively alleviate hypoxia and inhibit the growth of orthotopic gliomas. This work not only provides an effective means for real-time monitoring of the dynamic feedback between tumor hypoxia relief and therapeutic efficacy, but also offers a potential approach for the clinical treatment of gliomas.

Evaluation of calibrated and uncalibrated optical imaging approaches for relative cerebral oxygen metabolism measurements in awake mice

Objective. The continuous delivery of oxygen is critical to sustain brain function, and therefore, measuring brain oxygen consumption can provide vital physiological insight. In this work, we examine the impact of calibration and cerebral blood flow (CBF) measurements on the computation of the relative changes in the cerebral metabolic rate of oxygen consumption (rCMRO2) from hemoglobin-sensitive intrinsic optical imaging data. Using these data, we calculate rCMRO2, and calibrate the model using an isometabolic stimulus. Approach. We used awake head-fixed rodents to obtain hemoglobin-sensitive optical imaging data to test different calibrated and uncalibrated rCMRO2 models. Hypercapnia was used for calibration and whisker stimulation was used to test the impact of calibration. Main results. We found that typical uncalibrated models can provide reasonable estimates of rCMRO2 with differences as small as 7%–9% compared to their calibrated models. However, calibrated models showed lower variability and less dependence on baseline hemoglobin concentrations. Lastly, we found that supplying the model with measurements of CBF significantly reduced error and variability in rCMRO2 change calculations. Significance. The effect of calibration on rCMRO2 calculations remains understudied, and we systematically evaluated different rCMRO2 calculation scenarios that consider including different measurement combinations. This study provides a quantitative comparison of these scenarios to evaluate trade-offs that can be vital to the design of blood oxygenation sensitive imaging experiments for rCMRO2 calculation.

Exposure to persistent hemodynamically significant patent ductus arteriosus is associated with retinopathy of prematurity

BackgroundHemodynamically significant patent ductus arteriosus (hsPDA) shunt may predispose infants to retinopathy of prematurity (ROP) because of its higher preductal cardiac output and blood oxygen content, which may augment ocular oxygen delivery. MethodsA retrospective cohort study of preterm infants, born at <27 weeks’ gestation and admitted at <24h postnatal age to a large quaternary referral was conducted. The primary composite outcome was death at <32 weeks or moderate-to-severe ROP (≥stage 2 or requiring treatment) in either eye. Secondary outcomes included ROP requiring treatment, and any ROP. Univariate analysis of patient characteristics and outcomes was performed as well as logistic regression. A receiver operating characteristics curve was generated for the outcome of ROP ≥stage 2 or requiring treatment. ResultsA total of 91 patients were screened, of whom 86 (54 hsPDA, 32 controls) were eligible for inclusion. hsPDA patients were younger and lighter at birth and had a higher burden of hyperglycemia and respiratory illness. The rates of the composite outcome (death <32 weeks or moderate-to-severe ROP) and of any ROP were more frequent in the hsPDA group. hsPDA shunt exposure was independently associated with development of any ROP among survivors to assessment (P = 0.006). PDA cumulative exposure score of 78 (clinical equivalent = 7 days high-volume shunt exposure) predicts moderate-to-severe ROP with 80% sensitivity and 78% specificity. ConclusionsAmong infants <27 weeks, hsPDA shunt is associated with increased risks of a composite outcome of death or moderate-to-severe ROP, as well as ROP of any stage. Shunt modulation as a strategy to reduce ROP represents a biologically plausible avenue for investigation.

Dry cupping as an adjuvant treatment of individuals with severe pneumonia: study protocol for a placebo-controlled, randomised study

BackgroundSevere pneumonia (SP) stands as one of the most prevalent critical illnesses encountered in clinical practice, characterised by its rapid onset and progression, numerous complications and elevated mortality rates. While...

The epidemiology and treatment outcomes of COVID-19 patients admitted to an intensive care unit in an Iranian hospital in Neyshabur city.

The COVID-19 pandemic and the infection of numerous individuals from diverse societies have emerged as major global challenges. Given the limited resources in intensive care units, effective bed management and resource allocation require a deep understanding of the disease. This study aimed to assess the epidemiology and treatment outcomes of COVID-19 patients admitted to an intensive care unit in an Iranian hospital in Neyshabur city. This cross-sectional study was conducted on COVID-19 patients hospitalized in intensive care units in Razavi Khorasan, Iran in 2021. Census sampling was used to include all intensive care units. Of the initial 480 cases, 54 cases were excluded based on the exclusion criteria, leaving 426 cases for the study. Data were collected with the help of a data collection form that was designed by the researcher and its content validity and reliability were measured with Cronbach's alpha coefficient (α = 89%.). Data were analyzed with SPSS version 20 software. Descriptive and inferential statistics were used to analyze the data. Mean, standard deviation, and interquartile range indicators were used for descriptive statistics, and absolute frequency and relative frequency (percentage) were used to show numbers and ratios. The mean (SD) age of the patients was 66.33 (15.05) years, and 49.3% were female. The results showed that arterial blood oxygen saturation, respiratory rate, and Alzheimer's disease were significant variables for predicting mortality. Furthermore, arterial blood oxygen saturation, respiratory rate, and the need for transfusion of blood products were significant variables in predicting hospitalization and the risk of acute respiratory distress syndrome (ARDS). This study demonstrated that arterial blood oxygen saturation, respiratory rate, and Alzheimer's disease are crucial variables for predicting death. Furthermore, arterial blood oxygen saturation and respiratory rate are significant factors in predicting the risk of ARDS.

300 Psilocybin-induced changes in neural reactivity to alcohol and emotional cues in patients with alcohol use disorder: An fMRI pilot study

OBJECTIVES/GOALS: This pilot study investigated psilocybin-induced changes in neural reactivity to alcohol and emotional cues in patients with alcohol use disorder (AUD). METHODS/STUDY POPULATION: Participants were recruited from a phase II, randomized, double-blind, placebo-controlled clinical trial investigating psilocybin-assisted therapy (PAT) for the treatment of AUD (NCT02061293). Eleven adult patients completed task-based blood oxygen dependent functional magnetic resonance imaging (fMRI) approximately 3 days before and 2 days after receiving 25 mg of psilocybin (n = 5) or 50 mg of diphenhydramine (n = 6). Visual alcohol and emotionally valanced (positive, negative, or neutral) stimuli were presented in block design. RESULTS/ANTICIPATED RESULTS: Across both alcohol and emotional cues, psilocybin increased activity in the medial and lateral prefrontal cortex (PFC) and left caudate, and decreased activity in the insular, motor, temporal, parietal, and occipital cortices, and cerebellum. Unique to negative cues, psilocybin increased supramarginal gyrus activity; unique to positive cues, psilocybin increased right hippocampus activity and decreased left hippocampus activity. DISCUSSION/SIGNIFICANCE: Greater PFC and caudate engagement and concomitant insula, motor, and cerebellar disengagement suggests enhanced goal-directed action, improved emotional regulation, and diminished craving. The robust changes in brain activity observed in this pilot study warrant larger neuroimaging studies to elucidate neural mechanisms of PAT.

Real-time monitoring tool for heart rate and oxygen saturation in young adults

Health monitoring is crucial to maintain optimal well-being, especially for young adults. Wearable sensors have become popular for collecting healthcare data, but there are concerns regarding their reliability and safety, particularly with wireless sensors that use radio-frequency (RF) based devices. Researchers have proposed real-time monitoring systems for measuring heart rate beats per minute (BPM) and blood oxygen saturation (SpO2) saturation levels, but more studies are needed to determine the accuracy and user acceptance of these tools among young adults. To address these concerns, this study proposes a real-time monitoring tool that incorporates MAX 30100 sensors to collect heart rate BPM and SpO2 data. The collected data is then connected to a visualization platform, i.e., InfluxDB and Grafana, to provide valuable insights of the body’s physiological state. By testing the feasibility and usability of the tool, we found motivating differences in resting heart rates and changes in heart rate after activity between male and female participants. By developing this real-time monitoring tool and investigating gender-specific differences in heart rate and activity-induced changes, our study contributes to the advancement of health monitoring technologies for young adults, ultimately promoting personalized healthcare and well-being.

Dynamic Functional Hyperconnectivity After Psilocybin Intake Is Primarily Associated With Oceanic Boundlessness

BackgroundPsilocybin is a widely studied psychedelic substance that leads to the psychedelic state, a specific altered state of consciousness. To date, the relationship between the psychedelic state’s neurobiological and experiential patterns remains undercharacterized because they are often analyzed separately. We investigated the relationship between neurobiological and experiential patterns after psilocybin by focusing on the link between dynamic cerebral connectivity and retrospective questionnaire assessment. MethodsHealthy participants were randomized to receive either psilocybin (n = 22) or placebo (n = 27) and scanned for 6 minutes in an eyes-open resting state during the peak subjective drug effect (102 minutes posttreatment) in ultrahigh field 7T magnetic resonance imaging. The 5-Dimensional Altered States of Consciousness Rating Scale was administered 360 minutes after drug intake. ResultsUnder psilocybin, there were alterations across all dimensions of the 5-Dimensional Altered States of Consciousness Rating Scale and widespread increases in averaged brain functional connectivity. Time-varying functional connectivity analysis unveiled a recurrent hyperconnected pattern characterized by low blood oxygen level–dependent signal amplitude, suggesting heightened cortical arousal. In terms of neuroexperiential links, canonical correlation analysis showed higher transition probabilities to the hyperconnected pattern with feelings of oceanic boundlessness and secondly with visionary restructuralization. ConclusionsPsilocybin generates profound alterations at both the brain and the experiential levels. We suggest that the brain’s tendency to enter a hyperconnected-hyperarousal pattern under psilocybin represents the potential to entertain variant mental associations. These findings illuminate the intricate interplay between brain dynamics and subjective experience under psilocybin, thereby providing insights into the neurophysiology and neuroexperiential qualities of the psychedelic state.

Antarctic station Vostok as an analogue of a future lunar base: physiological reactions of the human cardiorespiratory system during a year-long exposure to the conditions of hypobaric hypoxia, isolation and hypokinesia

A number of physiological investigations focused on human cardiorespiratory system have been conducted at Vostok station in Central Antarctica during the wintering of 2019.During the one-year expedition at the Vostok station, the cardiorespiratory system gradually adapted to the unusual conditions of life and work in the isolated, confined and extreme (ICE) environment of Central Antarctica.We hypothesized that during a long stay in the conditions of the Central Antarctica the adaptation strategy to physical environmental conditions for representatives of two age groups will differ, which will be evident from the dynamics of indicators of the functioning of the cardiovascular system and when assessing the autonomic nervous system status.The level of blood oxygen saturation stabilized by the second month and was in the range of 86.0-91.0%, which corresponded to a reduced partial pressure of oxygen in the inhaled air. In terms of the respiratory system, central sleep apnea was noted in all subjects throughout the study. Quantitative analysis revealed that the average number of apneas per hour was 43, and their average duration was 25.2 seconds. The maximum apnea number was recorded at the beginning and middle of wintering, while before the end of the expedition the episodes became rarer. In all age groups there was a shortening of the PQ interval, with a tendency towards normalization by the end of wintering, while in the first age group the shortening of the interval was more significant than in the second, which apparently can be explained by a more pronounced active reaction of the sympathetic nervous system of polar explorers of the first age group.Adaptive Potential Index (API) level remained practically unchanged throughout the wintering period in 9 out of 11 members of the expedition. The API value was predominantly in the range from 2.11 to 3.20 points, which corresponds to the level of “adaptation stress”. The autonomous nervous system (ANS) status was assessed by Kerdo Index (KI) values. KI positive dynamic was noted in 90% of cases by the 5th month of wintering. A direct correlation was found between the degree of positive shift in the KI value and the age of the participant. The gained results do not allow us to state that ANS has fully adapted to the conditions of life and work at the station. The results of this investigation demonstrate stable and positive adaptation trend to the ICE environment of Central Antarctica throughout the study period, regardless of age and wintering experience.

Effects of Butorphanol on Respiration in White Rhinoceros (Ceratotherium simum) Immobilized with Etorphine-Azaperone.

This article reports on respiratory function in white rhinoceros (Ceratotherium simum) immobilized with etorphine-azaperone and the changes induced by butorphanol administration as part of a multifaceted crossover study that also investigated the effects of etorphine or etorphine-butorphanol treatments. Six male white rhinoceros underwent two immobilizations by using 1) etorphine-azaperone and 2) etorphine-azaperone-butorphanol. Starting 10 min after recumbency, arterial blood gases, limb muscle tremors, expired minute ventilation, and respiratory rate were evaluated at 5-min intervals for 25 min. Alveolar to arterial oxygen gradient, expected respiratory minute volume, oxygen consumption, and carbon dioxide production were calculated. Etorphine-azaperone administration resulted in hypoxemia and hypercapnia, with increases in alveolar to arterial oxygen gradient, oxygen consumption, and carbon dioxide production, and a decrease in expired minute ventilation. Muscle tremors were also observed. Intravenous butorphanol administration in etorphine-azaperone-immobilized white rhinoceros resulted in less hypoxemia and hypercapnia; a decrease in oxygen consumption, carbon dioxide production, and expired minute ventilation; and no change in the alveolar to arterial oxygen gradient and rate of breathing. We show that the immobilization of white rhinoceros with etorphine-azaperone results in hypoxemia and hypercapnia and that the subsequent intravenous administration of butorphanol improves both arterial blood oxygen and carbon dioxide partial pressures.

ПРОГНОЗИРОВАНИЕ ПРОГРЕССИРОВАНИЯ ИНТЕРСТИЦИАЛЬНОГО ЗАБОЛЕВАНИЯ ЛЁГКИХ У ПАЦИЕНТОВ С СИСТЕМНОЙ СКЛЕРОДЕРМИЕЙ: АНАЛИЗ ДАННЫХ КОГОРТНОГО ИССЛЕДОВАНИЯ

Introduction. Systemic sclerosis (scleroderma) is an autoimmune disease that often causes inflammatory fibrosing lesions of the pulmonary interstitial tissue, referred to as interstitial lung disease. It is associated with a significant reduction in survival and is the leading immediate cause of the systemic scleroderma patients’ death. Progression rate of interstitial lung disease varies greatly. Since the specific immunosuppressive and antifibrotic treatment is only justified in case of progressive lesions, predicting the interstitial lung disease progression is of great practical importance. Aim: To develop approaches to predicting the progression of interstitial lung disease in systemic scleroderma patients. Materials and Methods. Our analysis included the data of patients observed in the Registry of Myositis, Systemic Scleroderma and Mixed Diseases (REMISSiZ). Inclusion criteria: Age 18+ years, the proven case of systemic scleroderma, eligibility for ACR/EULAR (2013), and the repeated high-resolution computed tomography of lungs with an interval of at least 1 year. All patients underwent 6-minute walking tests. Results and Discussion. The study included 44 patients (43 women) aged 62.9 ± 11.5 years in average. The average follow-up duration was 530 ± 231 days. Radiological progression was associated with younger age, p=0.03, severity of Raynaud’s phenomenon, p=0.032, shorter disease duration, p=0.038, and shorter distance covered in the 6-minute walk test, p=0.05. The progression of functional impairment, determined by the dynamics of the distance covered in the 6-minute walk test, was associated with a decrease in blood oxygen saturation at rest (p=0.003), the severity of breath shortness according to the Borg scale (p=0.006), the initial distance of the 6-minute walk test (p &lt;0.001), the presence of topoisomerase I antibodies (anti-Scl-70, p=0.034), and complaints of breath shortness (p=0.043) and dysphagia (p=0.034). As a result of reverse stepwise selection of variables, three independent significant predictors were selected from the above indicators: Dysphagia, anti-Scl-70, and the initial walking distance in the 6-minute walk test. Based on these indicators, a regression formula is presented for predicting the progression of functional impairment in systemic scleroderma patients. Conclusions. X-ray-detected progression of interstitial lung disease in systemic sclerosis patients is associated with younger age and Raynaud’s phenomenon severity. To predict the decline in the systemic sclerosis patients’ functionality, it is advisable to consider the presence of dysphagia and topoisomerase I antibodies (anti-Scl-70).

Mean airway pressure as a parameter of lung-protective and heart-protective ventilation

Mean airway pressure (MAP) is the mean pressure generated in the airway during a single breath (inspiration + expiration), and is displayed on most anaesthesia and intensive care ventilators. This parameter, however, is not usually monitored during mechanical ventilation because it is poorly understood and usually only used in research. One of the main determinants of MAP is PEEP. This is because in respiratory cycles with an I:E ratio of 1:2, expiration is twice as long as inspiration. Although MAP can be used as a surrogate for mean alveolar pressure, these parameters differ considerably in some situations. Recently, MAP has been shown to be a useful prognostic factor for respiratory morbidity and mortality in mechanically ventilated patients of various ages. Low MAP has been associated with a lower incidence of 90-day mortality, shorter ICU stay, and shorter mechanical ventilation time. MAP also affects haemodynamics: there is evidence of a causal relationship between high MAP and low perfusion index, both of which are associated with poor prognosis in mechanically ventilated patients. Elevated MAP values have also been associated with high central venous pressure and lactate, which are indicative of ventilator-associated right ventricular failure and tissue hypoperfusion, respectively. MAP, therefore, is an important parameter to measure in clinical practice. The aim of this review has been to identify the determinants of MAP, the pros and cons of using MAP instead of traditional protective ventilation parameters, and the evidence that supports the use of MAP in clinical practice.

Association of the perfusion index with postoperative acute kidney injury: a retrospective study.

Association of the perfusion index with postoperative acute kidney injury: a retrospective study.

Sacubitril/valsartan reversal of left ventricular remodeling is associated with improved hemodynamics in resistant hypertension

BackgroundSacubitril/valsartan (S/V) has been shown to be an effective antihypertensive drug combination. However, its therapeutic effects on blood pressure (BP), hemodynamics, and left ventricular (LV) remodeling in resistant hypertension (RHTN) remain unclear. MethodsEighty-six patients completed this self-control study, during which olmesartan was administered within the first 8 weeks (phase 1), followed by S/V within the second 8 weeks (phase 2), with nifedipine and hydrochlorothiazide taken as background medications. Office BP, echocardiography, and hemodynamics assessment using impedance cardiography were performed at baseline and at the eighth and sixteenth weeks. ResultsThe reduction in office BP was larger in phase 2 than in phase 1 (19.59/11.66 mmHg vs. 2.88/1.15 mmHg). Furthermore, the treatment in phase 2 provided greater reductions in systemic vascular resistance index (SVRI) and thoracic blood saturation ratio (TBR), with differences between the two phases of −226.59 (−1212.80 to 509.55) dyn·s/cm5/m2 and −0.02 (−0.04 to 0.02). Switching from olmesartan to S/V also significantly reduced E/E′, LV mass index, LV end-diastolic volume index, and LV end-systolic volume index (all P < 0.05). Decreases in arterial stiffness, SVRI, and TBR were correlated with changes in indicators of LV remodeling (all P < 0.05). This correlation persisted even after adjusting for confounders including changes in BP. ConclusionsSwitching from olmesartan to S/V effectively lowered BP and reversed ventricular remodeling in RHTN. In addition, hemodynamic improvement was also observed. Changes in hemodynamics played an important role in reversing LV remodeling of S/V, and were independent of its antihypertensive effect.