Oxygen reserve index

Pulse oximetry (SpO2 ) identifies a decrease in the partial pressure of oxygen (PaO2 ) when it falls below 80 mmHg, while oxygen reserve index (ORi), a dimensionless index ranging from 0 to 1, detects PaO2 changes between 100 and 200 mmHg. This study investigates the usefulness of ORi in detecting impending deoxygenation before traditional SpO2 . Fifty-one dogs undergoing anesthesia were mechanically ventilated maintaining a fraction of inspired oxygen of 0.50 and an ORi of 1. Animals were classified according to their body condition score (BCS) as normal-fit (BCS 4-5/9), overweight (BCS 6-7/9), or obese (BCS 8-9/9)...

OBJECTIVES: Fetuses with single ventricle physiology (SVP) exhibit reductions in fetal cerebral oxygenation with associated delays in fetal brain growth and neurodevelopmental outcomes. Maternal supplemental oxygen (MSO) has been proposed to improve fetal brain growth but current evidence on dosing, candidacy, and outcomes are limited. In this pilot study, we evaluated the safety and feasibility of continuous low-dose MSO in the setting of SVP. METHODS: This single-centre, open-label, pilot phase 1 safety and feasibility clinical trial included 25 pregnant individuals with a fetal diagnosis of SVP...

BACKGROUND: Exercise intolerance is a common symptom associated with atrial fibrillation (AF). However, echocardiographic markers that can predict impaired exercise capacity are lacking. OBJECTIVE: To investigate the association between echocardiographic parameters and exercise capacity assessed via cardiopulmonary exercise testing (CPET) in patients with AF. METHODS: This single-center prospective study enrolled patients with AF who underwent echocardiography and CPET to evaluate exercise capacity at a tertiary center for AF management from 2020 to 2022...

PURPOSE: Robot-assisted radical prostatectomy (RARP) is a common surgical procedure for the treatment of prostate cancer. Although beneficial, it can lead to intraoperative hypoxia due to high-pressure pneumoperitoneum and Trendelenburg position. This study explored the use of oxygen reserve index (ORi) to monitor and predict hypoxia during RARP. METHODS: A retrospective analysis was conducted on 329 patients who underwent RARP at the Seoul National University Bundang Hospital between July 2021 and March 2023...

With the advantages of lightweight and low thermal conductivity properties, polymeric foams are widely employed as thermal insulation materials for energy-saving buildings but suffer from inherent flammability. Flame-retardant coatings hold great promise for improving the fire safety of these foams without deteriorating mechanical-physical properties of the foam. In this work, four kinds of sulfur-based flame-retardant copolymers are synthesized via a facile radical copolymerization. The sulfur-containing monomers serve as flame-retardant agents, including vinyl sulfonic acid sodium (SPS), ethylene sulfonic acid sodium (VS), and sodium p-styrene sulfonate (VSS)...

BACKGROUND: Premature ovarian insufficiency (POI) is a major cause of infertility. In this study, we aimed to investigate the effects of the combination of bone marrow mesenchymal stem cells (BMSCs) and moxibustion (BMSCs-MOX) on POI and evaluate the underlying mechanisms. METHODS: A POI rat model was established by injecting different doses of cyclophosphamide (Cy). The modeling of POI and the effects of the treatments were assessed by evaluating estrous cycle, serum hormone levels, ovarian weight, ovarian index, and ovarian histopathological analysis...

Central sleep apnea (CSA) is rare in older children. Although CSA mostly arises from neurological diseases such as Chiari malformation, the frequency of CSA is significantly higher in obese children. Herein, we describe the case of a 14-yr-old boy who presented with CSA secondary to severe obesity and a history of traumatic lateral medullary syndrome at 8 yr of age. Polysomnography revealed severe sleep apnea syndrome with apnea-hypopnea index of 41.4 per hour and central apnea index of 8.9 per hour. Magnetic resonance imaging of the head showed no new brainstem or cerebellar infarcts; however, old changes in the cerebellar infarction persisted...

INTRODUCTION: Continuous monitoring of the pressure reactivity index (PRx) provides an estimation of dynamic cerebral autoregulation (CA) at the bedside in traumatic brain injury (TBI) patients. Visualising the time-trend of PRx with a risk bar chart in ICM + software at the bedside allows for better real-time interpretability of the autoregulation status. When PRx>0.3 is sustained for long periods, typically of at least half an hour, the bar shows a pattern called "red solid line" (RSL)...

BACKGROUND: Contemporary radiotherapy for the treatment of lung cancer is effective in targeting tumor tissue while limiting heart exposure, yet cardiac toxicity still occurs, often becoming clinically apparent years later. Cardiorespiratory fitness (CRF) is an independent predictor of cardiovascular, cancer-related, and overall mortality and may serve as a sensitive measure of subclinical cardiac toxicity following anti-cancer treatments. Prior work has demonstrated a significant relationship between reduced CRF and impaired left-ventricular (LV) diastolic reserve in cancer survivors following thoracic radiotherapy...

Increased left atrial (LA) size and reduced LA function have been associated with heart failure and atrial fibrillation (AF) in at risk populations. However, atrial remodeling has also been associated with exercise training and the relationship between fitness, LA size and function has not been defined across the fitness spectrum. In a cross-sectional study of 559 ostensibly healthy participants, comprising 304 males (mean age 46 ± 20 years) and 255 females (mean age 47 ± 15 years), we sought to define the relationship between cardiorespiratory fitness (CRF), LA size and function...

OBJECTIVE: To examine the cardiorespiratory effects of a forced-rate aerobic exercise (FE) intervention among individuals with chronic stroke compared to an upper extremity repetitive task practice (UE RTP) control group. DESIGN: Secondary analysis of data from a randomized clinical trial. SETTING: Research laboratory. PARTICIPANTS: Individuals with chronic stroke (N=60). INTERVENTIONS: Participants completed 24 sessions of FE followed by RTP (FE+RTP, N=30) or time matched RTP alone (N=30)...

The intelligent construction of non-noble metal materials that exhibit reversible oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with bifunctional electrocatalytic performance is greatly coveted in the realm of znic-air batteries (ZABs). Herein, a crafted structure-amorphous MnO2 lamellae encapsulated covalent triazine polymer-derived N, S, P co-doped carbon sphere (A-MnO2 /NSPC) is designed using a self-doped pyrolysis coupled with an in-situ encapsulation strategy. The customized A-MnO2 /NSPC-2 demonstrates a superior bifunctional electrocatalytic performance, confirmed by a small ΔE index of 0...

Intervertebral disc degeneration (IVDD) is invariably accompanied by excessive accumulation of reactive oxygen species (ROS), resulting in progressive deterioration of mitochondrial function and senescence in nucleus pulposus cells (NPCs). Significantly, the main ROS production site in non-immune cells is mitochondria, suggesting mitochondria is a feasible therapeutic target to reverse IVDD. Triphenylphosphine (TPP), which is known as mitochondrial-tropic ligands, is utilized to modify carbon dot-supported Prussian blue (CD-PB) to scavenge superfluous intro-cellular ROS and maintain NPCs at normal redox levels...

INTRODUCTION: There is no consensus on whether cardiopulmonary reserve affects the risk of gravity-induced loss of consciousness (G-LOC) or almost loss of consciousness (A-LOC). Few previous studies have used cardiopulmonary exercise testing (CPET) to assess cardiopulmonary reserve function (CPRF) of fighter aviators. We compared CPET-related parameters in G-LOC/A-LOC and non-G-LOC/A-LOC fighter aviators to explore the effect of cardiopulmonary reserve function on G tolerance. METHODS: A total of 264 male fighter aviators with more than 500 h of flight experience participated in the study, all of whom underwent CPET and human centrifuge testing...

AIM: To assess the effectiveness of fraction of inspired oxygen (FiO2) titration guided by oxygen reserve index (ORi) in preventing hyperoxia in intensive care unit (ICU) patients receiving mechanical ventilator support. METHODS: Patients aged 18 years and older who were admitted to a tertiary ICU and required mechanical ventilator support were randomly divided into two groups: the control group (n=30) and the oxygen saturation (SpO2) +ORi group (n=30). In the SpO2+ORi group, the goal was to maintain SpO2 between 95% and 98% and ORi at 0...

AIMS: This study evaluated the sex differences of sequential changes in coronary blood flows and microvascular function in patients with suspected angina but with no obstructed coronary arteries. METHODS: A total of 202 consecutive patients who experienced chest pain but had no significant coronary artery stenosis and who underwent adenosine stress echocardiography were included in the study. Coronary blood flow (CBF) velocities were measured at 1, 2, and 3 min after adenosine infusion...

Arctic char ( Salvelinus alpinus ) is facing the decline of its southernmost populations due to several factors including rising temperatures and eutrophication. These conditions are also conducive to episodes of cyclic hypoxia, another possible threat to this species. In fact, lack of oxygen and reoxygenation can both have serious consequences on fish as a result of altered ATP balance and an elevated risk of oxidative burst. Thus, fish must adjust their phenotype to survive and equilibrate their energetic budget...

BACKGROUND: Staging of hemodynamic failure (HF) in symptomatic patients with cerebrovascular steno-occlusive disease is required to assess the risk of ischemic stroke. Since the gold standard positron emission tomography-based perfusion reserve is unsuitable as a routine clinical imaging tool, blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR) with CO2 is a promising surrogate imaging approach. We investigated the accuracy of standardized BOLD-CVR to classify the extent of HF...

OBJECTIVE: The aim of this study was to observe the changes in pleth variability index (PVI), perfusion index (PI) and other hemodynamic parameters in adult individuals who had had Coronavirus disease 2019 (COVID-19) and were currently living a normal life. A further aim was to draw attention to the fact that some hemodynamic changes after COVID-19 may cause long-term health problems. PATIENTS AND METHODS: A total of 174 adult individuals who had had COVID-19 and were currently living a normal life and 56 healthy individuals with similar demographic characteristics who had not had COVID-19 were included in the study...

INTRODUCTION: We aimed to evaluate the difference in intraoperative oxygen reserve index (ORi) between the sedatives remimazolam (RMMZ) and dexmedetomidine (DEX). METHODS: Seventy-eight adult patients scheduled for sedation under regional anesthesia were randomly assigned to either the DEX ( n = 39) or RMMZ ( n = 39) group. The primary outcome was the difference in perioperative ORi between the groups. The secondary outcomes included respiratory depression, hypo- or hypertension, heart rate (HR), blood pressure, respiratory rate and postoperative outcomes...