20,679 results match your criteria tidal volume

Simultaneous decoding of cardiovascular and respiratory functional changes from pig intraneural vagus nerve signals.

J Neural Eng 2021 Jun 21. Epub 2021 Jun 21.

Center for Neuroprosthetics and Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Chemin de Mines 9, Geneva, 1202, SWITZERLAND.

Objective: Bioelectronic medicine is opening new perspectives for the treatment of some major chronic diseases through the physical modulation of autonomic nervous system activity. Being the main peripheral route for electrical signals between central nervous system and visceral organs, the vagus nerve (VN) is one of the most promising targets. Closed-loop VN stimulation would be crucial to increase effectiveness of this approach. Read More

View Article and Full-Text PDF

Physiological Factors Affecting Lung Deposition.

Chong S Kim

J Aerosol Med Pulm Drug Deliv 2021 Jun;34(3):147-154

Senior Research Scientist, Public Health and Integrated Tocxicology Division, Center for Public Health and Environmental Effects, U.S. Environmental Protection Agency, Reserach Triangle Park, North Carolina, USA.

Ventilation and mechanics of breathing are an integral part of respiratory physiology that directly affect aerosol transport and deposition in the lung. Although natural breathing pattern varies widely among individuals, breathing pattern is controllable, and by using an appropriate breathing pattern, aerosol deposition can be substantially modified for desired purposes. Effects of breathing pattern have been investigated under carefully controlled inhalation conditions covering a wide range of tidal volumes (V) and breathing frequencies (f) or respiratory times (T = 1/f). Read More

View Article and Full-Text PDF

Assisted ventilation immediately after birth with self-inflating bag versus T-piece resuscitator in preterm infants.

J Neonatal Perinatal Med 2021 Jun 17. Epub 2021 Jun 17.

New York Presbyterian Morgan Stanley Children's Hospital, New York, NY, USA.

Objective: To compare proportions of target range tidal volumes achieved with the self-inflating bag vs. the T-piece in resuscitation of preterm newborns at delivery.

Study Design: This randomized controlled trial was conducted at a tertiary Children's Hospital. Read More

View Article and Full-Text PDF

Respiratory Physiology of Prone Positioning With and Without Inhaled Nitric Oxide Across the Coronavirus Disease 2019 Acute Respiratory Distress Syndrome Severity Spectrum.

Crit Care Explor 2021 Jun 15;3(6):e0471. Epub 2021 Jun 15.

Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA.

Importance: Prone positioning improves clinical outcomes in moderate-to-severe acute respiratory distress syndrome and has been widely adopted for the treatment of patients with acute respiratory distress syndrome due to coronavirus disease 2019. Little is known about the effects of prone positioning among patients with less severe acute respiratory distress syndrome, obesity, or those treated with pulmonary vasodilators.

Objectives: We characterize the change in oxygenation, respiratory system compliance, and dead-space-to-tidal-volume ratio in response to prone positioning in patients with coronavirus disease 2019 acute respiratory distress syndrome with a range of severities. Read More

View Article and Full-Text PDF

Efficacy of budesonide in the prevention and treatment of bronchopulmonary dysplasia in premature infants and its effect on pulmonary function.

Am J Transl Res 2021 15;13(5):4949-4958. Epub 2021 May 15.

Department of Neonatology, Qinghai Red Cross Hospital Xining, Qinghai Province, China.

Objective: This study was designed to explore the efficacy of budesonide (BUD) in preventing and treating bronchopulmonary dysplasia (BPD) in premature infants and its effect on pulmonary function.

Methods: A total of 94 premature infants with BPD who were born in our hospital were selected as the research subjects and divided into the control group (47 cases) for routine treatment and the research group (47 cases) for BUD therapy on the basis of routine treatment according to the random number table method. The incidence of BPD and the time of oxygen inhalation, ventilator ventilation, extubation and hospitalization were recorded in the two groups. Read More

View Article and Full-Text PDF

Comparison of Two Metabolic Simulators Used for Gas Exchange Verification in Cardiopulmonary Exercise Test Carts.

Front Physiol 2021 3;12:667386. Epub 2021 Jun 3.

Vyaire Medical, Mettawa, IL, United States.

Introduction: Metabolic simulators (MS) produce simulated human breaths for the purpose of verification of cardiopulmonary exercise test (CPET) equipment. MS should produce consistent identical breaths with known CO and O gas concentrations over a range of breath rates and tidal volumes. Reliability of a CPET metabolic cart depends on ongoing quality control and maintenance of the device, including intermittent verification with a MS. Read More

View Article and Full-Text PDF

Gastric and urinary bladder pressures correlate with intra-abdominal pressure in patients with morbid obesity.

J Clin Monit Comput 2021 Jun 17. Epub 2021 Jun 17.

Ruth & Bruce Rappaport Faculty of Medicine, Technion- Israel Institute of Technology, Haifa, Israel.

Intra-abdominal pressure (IAP) affects cardio-respiratory and hemodynamic parameters and can be measured directly or indirectly by measuring gastric or urinary bladder pressure. The aim of this study was to investigate the correlation between IAP, gastric pressure and urinary bladder pressure in patients with morbid obesity, at normal and elevated levels of IAP in two positions. As well, to examine the effects of increasing IAP and patient's position on hemodynamic and respiratory parameters. Read More

View Article and Full-Text PDF

Relationship Between Cerebrovascular Reactivity and Cognition Among People With Risk of Cognitive Decline.

Front Physiol 2021 31;12:645342. Epub 2021 May 31.

Department of Biomedical Engineering, University of California, Davis, Davis, CA, United States.

Vascular risk factors (e.g., obesity and hypertension) are associated with cerebral small vessel disease, Alzheimer's disease (AD) pathology, and dementia. Read More

View Article and Full-Text PDF

Safety Pharmacology Study of ET-26 Hydrochloride, a Potential Drug for Intravenous General Anesthesia, in Rats and Beagle Dogs.

Front Pharmacol 2021 31;12:679381. Epub 2021 May 31.

Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China.

ET-26 hydrochloride (ET-26HCl), a class 1 new drug, was developed to reserve the advantages of etomidate with a mild adrenocortical inhibition. this study was to evaluate the potential adverse effects on the cardiovascular system of beagle dogs and the respiratory and central nervous systems of rats. three established methods, the whole-body plethysmography for respiratory function, the prototype telemetry transmitter for cardiovascular function, and the standardized functional observational battery for central nervous system function, were accomplished with Good Laboratory Practice standards. Read More

View Article and Full-Text PDF

Introduction to the theme issue: Measuring physiology in free-living animals.

Philos Trans R Soc Lond B Biol Sci 2021 Aug 14;376(1830):20200210. Epub 2021 Jun 14.

Atmosphere and Ocean Research Institute, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba Prefecture 277-8564, Japan.

By describing animals go, biologging technologies (i.e. animal attached logging of biological variables with small electronic devices) have been used to document the remarkable athletic feats of wild animals since the 1940s. Read More

View Article and Full-Text PDF

Early vs. late tracheostomy in ventilated COVID-19 patients - A retrospective study.

Am J Otolaryngol 2021 Jun 7;42(6):103102. Epub 2021 Jun 7.

Department of Otolaryngology Head and Neck Surgery, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.

Background: Tracheostomy is one of the most common surgical procedures performed on ventilated COVID-19 patients, yet the appropriate timing for operating is controversial.

Objectives: Assessing the effect of early tracheostomy on mortality and decannulation; elucidating changes in ventilation parameters, vasopressors and sedatives dosages immediately following the procedure.

Methods: A retrospective cohort of 38 ventilated COVID-19 patients, 19 of them (50%) underwent tracheostomy within 7 days of intubation (early tracheostomy group) and the rest underwent tracheostomy after 8 days or more (late tracheostomy group). Read More

View Article and Full-Text PDF

Menstrual phase does not influence ventilatory responses to group III/IV afferent signaling in eumenorrheic young females.

Respir Physiol Neurobiol 2021 Jun 9;292:103712. Epub 2021 Jun 9.

Division of Physical Therapy, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN, 55455, United States; Division of Rehabilitation Science, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN, 55455, United States.

Estrogen can reduce sympathetic activity, but its effects on minute ventilation (V) with group III/IV afferent activation remain unclear. This study examined the influence of estrogen on V during lower-extremity exercise with group III/IV activation. Females completed two identical visits in follicular and ovulatory menstrual phases. Read More

View Article and Full-Text PDF

How does cervical spinal cord injury impact the cardiopulmonary response to exercise?

Respir Physiol Neurobiol 2021 Jun 9;293:103714. Epub 2021 Jun 9.

International Collaboration on Repair Discoveries, Vancouver, BC, V5Z 1M9, Canada; Canadian Sport Institute - Pacific, Victoria, BC, V9E 2C5, Canada; Faculty of Medicine, University of British Columbia, Kelowna, BC, V1Y 1T3, Canada. Electronic address:

We compared cardiopulmonary responses to arm-ergometry in individuals with cervical spinal cord injury (C-SCI) and able-bodied controls. We hypothesized that individuals with C-SCI would have higher respiratory frequency (f) but lower tidal volume (VT) at a given work rate and dynamically hyperinflate during exercise, whereas able-bodied individuals would not. Participants completed pulmonary function testing, an arm-ergometry test to exhaustion, and a sub-maximal exercise test consisting of four-minute stages at 20, 40, 60, and 80% peak work rate. Read More

View Article and Full-Text PDF

Tidal volume measurements in the delivery room in preterm infants requiring positive pressure ventilation via endotracheal tube-feasibility study.

J Perinatol 2021 Jun 10. Epub 2021 Jun 10.

Division of Newborn Medicine, Department of Pediatrics, Tufts Children's Hospital, Boston, MA, USA.

Objective: Current delivery room (DR) resuscitation utilizes pressure-limited devices without tidal volume (TV) measurements. Clinicians use chest expansion as a surrogate, which is a poor indicator of TV. TV in early life can be highly variable due to rapidly changing lung compliance. Read More

View Article and Full-Text PDF

Diaphragm neurostimulation during mechanical ventilation reduces atelectasis and transpulmonary plateau pressure, preserving lung homogeneity and PaO2/FiO2.

J Appl Physiol (1985) 2021 Jun 10. Epub 2021 Jun 10.

grid.61971.38Simon Fraser University, British Columbia, Canada.

Tidal volume delivered by mechanical ventilation to a sedated patient is distributed in a non-physiological pattern, causing atelectasis (underinflation) and overdistension (overinflation). Activation of the diaphragm during mechanical ventilation provides a way to reduce atelectasis and alveolar inhomogeneity, protecting the lungs from ventilator-induced lung injury while also protecting the diaphragm by preventing ventilator-induced diaphragm dysfunction. We studied the hypothesis that diaphragm contractions elicited by transvenous phrenic nerve stimulation, delivered in synchrony with volume-control ventilation, would reduce atelectasis and lung inhomogeneity in a healthy, normal-lung pig model. Read More

View Article and Full-Text PDF

Effect of portable non-invasive ventilation on thoracoabdominal volumes in recovery from intermittent exercise in patients with COPD.

J Appl Physiol (1985) 2021 Jun 10. Epub 2021 Jun 10.

Department of Sport, Exercise and Rehabilitation, grid.42629.3bNorthumbria University, Newcastle Upon-Tyne, United Kingdom.

Background: We previously showed that use of portable non-invasive ventilation (pNIV) during recovery periods within intermittent exercise improved breathlessness and exercise tolerance in COPD patients compared to pursed-lip breathing (PLB). However, in a minority of patients recovery from dynamic hyperinflation (DH) was better with PLB, based on inspiratory capacity. We further explored this using Optoelectronic Plethysmography to assess total and compartmental thoracoabdominal volumes. Read More

View Article and Full-Text PDF

Reference equations for tidal breathing parameters using structured light plethysmography.

ERJ Open Res 2021 Apr 7;7(2). Epub 2021 Jun 7.

Lung Function and Sleep, Queen Elizabeth Hospital, Birmingham, UK.

Tidal breathing measurements can be used to identify changes in respiratory status. Structured light plethysmography (SLP) is a non-contact tidal breathing measurement technique. Lack of reference equations for SLP parameters makes clinical decision-making difficult. Read More

View Article and Full-Text PDF

An appraisal of respiratory system compliance in mechanically ventilated covid-19 patients.

Crit Care 2021 06 9;25(1):199. Epub 2021 Jun 9.

Critical Care Research Group, The Prince Charles Hospital, Chermside, Australia.

Background: Heterogeneous respiratory system static compliance (C) values and levels of hypoxemia in patients with novel coronavirus disease (COVID-19) requiring mechanical ventilation have been reported in previous small-case series or studies conducted at a national level.

Methods: We designed a retrospective observational cohort study with rapid data gathering from the international COVID-19 Critical Care Consortium study to comprehensively describe C-calculated as: tidal volume/[airway plateau pressure-positive end-expiratory pressure (PEEP)]-and its association with ventilatory management and outcomes of COVID-19 patients on mechanical ventilation (MV), admitted to intensive care units (ICU) worldwide.

Results: We studied 745 patients from 22 countries, who required admission to the ICU and MV from January 14 to December 31, 2020, and presented at least one value of C within the first seven days of MV. Read More

View Article and Full-Text PDF

Effects of The Prone Position on Regional Neutrophilic Lung Inflammation According To 18F-FDG PET In An Experimental Ventilator-Induced Lung Injury Model.

Shock 2021 Jun 8. Epub 2021 Jun 8.

Department of Emergency and Critical Care Center, Mie University Hospital, Tsu, Japan Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan Department of Molecular Imaging, Institute for Medical Photonics Research, Hamamatsu University School of Medicine, Hamamatsu, Japan Department of Surgery, National Defense Medical College, Tokorozawa, Japan Division of Acute and Critical Care Medicine, Department of Anesthesiology and Critical Care Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan Division of Anesthesia and Perioperative Medicine, Department of Anesthesiology and Critical Care Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan Department of Acute and Critical Care Medicine, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.

Abstract: Ventilator-induced lung injury (VILI) can be life-threatening and it is important to prevent the development of VILI. It remains unclear whether the prone position affects neutrophilic inflammation in the lung regions in vivo, which plays a crucial role in the pathogenesis of VILI. This study aimed to assess the relationship between the use of the prone position and the development of VILI-associated regional neutrophilic lung inflammation. Read More

View Article and Full-Text PDF

Target volume-guarantee in high-frequency oscillatory ventilation for preterm respiratory distress syndrome: Low volumes and high frequencies lead to adequate ventilation.

Pediatr Pulmonol 2021 Jun 9. Epub 2021 Jun 9.

Division of Neonatology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.

Background And Objectives: Respiratory distress syndrome (RDS) and ventilation-induced lung injury lead to significant morbidity in preterm infants. High-frequency oscillatory ventilation with volume-guarantee (HFOV-VG) has been used as a rescue therapy and might lead to lower rates of death and bronchopulmonary dysplasia, especially when using low tidal volumes and high frequencies. The aim of the study was to define HFOV-VG parameters leading to adequate ventilation in the first 72 h of preterm RDS using a low volume and high-frequency strategy. Read More

View Article and Full-Text PDF

Pleural Pressure Targeted Positive Airway Pressure Improves Cardiopulmonary Function in Spontaneously Breathing Patients With Obesity.

Chest 2021 Jun 8;159(6):2373-2383. Epub 2021 May 8.

Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA; Department of Respiratory Care, Massachusetts General Hospital and Harvard Medical School, Boston, MA. Electronic address:

Background: Increased pleural pressure affects the mechanics of breathing of people with class III obesity (BMI > 40 kg/m).

Research Question: What are the acute effects of CPAP titrated to match pleural pressure on cardiopulmonary function in spontaneously breathing patients with class III obesity?

Study Design And Methods: We enrolled six participants with BMI within normal range (control participants, group I) and 12 patients with class III obesity (group II) divided into subgroups: IIa, BMI of 40 to 50 kg/m; and IIb, BMI of ≥ 50 kg/m. The study was performed in two phases: in phase 1, participants were supine and breathing spontaneously at atmospheric pressure, and in phase 2, participants were supine and breathing with CPAP titrated to match their end-expiratory esophageal pressure in the absence of CPAP. Read More

View Article and Full-Text PDF

Flow Index: a novel, non-invasive, continuous, quantitative method to evaluate patient inspiratory effort during pressure support ventilation.

Crit Care 2021 06 7;25(1):196. Epub 2021 Jun 7.

Department of Anesthesia and Intensive Care, Fondazione Poliambulanza, Brescia, Italy.

Background: The evaluation of patient effort is pivotal during pressure support ventilation, but a non-invasive, continuous, quantitative method to assess patient inspiratory effort is still lacking. We hypothesized that the concavity of the inspiratory flow-time waveform could be useful to estimate patient's inspiratory effort. The purpose of this study was to assess whether the shape of the inspiratory flow, as quantified by a numeric indicator, could be associated with inspiratory effort during pressure support ventilation. Read More

View Article and Full-Text PDF

Closed-Loop Versus Conventional Mechanical Ventilation in COVID-19 ARDS.

J Intensive Care Med 2021 Jun 8:8850666211024139. Epub 2021 Jun 8.

Institute of Intensive Care Medicine, 27243University Hospital of Zurich, Zurich, Switzerland.

Background: Lung-protective ventilation is key in bridging patients suffering from COVID-19 acute respiratory distress syndrome (ARDS) to recovery. However, resource and personnel limitations during pandemics complicate the implementation of lung-protective protocols. Automated ventilation modes may prove decisive in these settings enabling higher degrees of lung-protective ventilation than conventional modes. Read More

View Article and Full-Text PDF

Identification and analysis of stable breathing periods in electrical impedance tomography recordings.

Physiol Meas 2021 Jun 7. Epub 2021 Jun 7.

Department of Anaesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein Campus Kiel, Kiel, GERMANY.

Objective: In this paper, an automated stable tidal breathing period (STBP) identification method based on processing Electrical Impedance Tomography (EIT) waveforms is proposed and the possibility of detecting and identifying such periods using EIT waveforms is analyzed. In wearable chest EIT, patients breathe spontaneously, and therefore, their breathing pattern might not be stable. Since most of the EIT feature extraction methods are applied to STBPs, this renders their automatic identification of central importance. Read More

View Article and Full-Text PDF

Protective ventilation and outcomes of critically ill patients with COVID-19: a cohort study.

Ann Intensive Care 2021 Jun 7;11(1):92. Epub 2021 Jun 7.

Divisao de Pneumologia, Instituto Do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo, Brazil.

Background: Approximately 5% of COVID-19 patients develop respiratory failure and need ventilatory support, yet little is known about the impact of mechanical ventilation strategy in COVID-19. Our objective was to describe baseline characteristics, ventilatory parameters, and outcomes of critically ill patients in the largest referral center for COVID-19 in Sao Paulo, Brazil, during the first surge of the pandemic.

Methods: This cohort included COVID-19 patients admitted to the intensive care units (ICUs) of an academic hospital with 94 ICU beds, a number expanded to 300 during the pandemic as part of a state preparedness plan. Read More

View Article and Full-Text PDF

Management of hypercapnia in critically ill mechanically ventilated patients-A narrative review of literature.

J Intensive Care Soc 2020 Nov 30;21(4):327-333. Epub 2020 Mar 30.

ANZIC-RC, Department of Epidemiology & Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.

The use of lower tidal volume ventilation was shown to improve survival in mechanically ventilated patients with acute lung injury. In some patients this strategy may cause hypercapnic acidosis. A significant body of recent clinical data suggest that hypercapnic acidosis is associated with adverse clinical outcomes including increased hospital mortality. Read More

View Article and Full-Text PDF
November 2020

Use of pressure-regulated volume control in the first 48 hours of hospitalization of mechanically ventilated patients with sepsis or septic shock, with or without ARDS.

J Intensive Care Soc 2020 Nov 21;21(4):305-311. Epub 2019 Oct 21.

Department of Medicine, Pulmonary & Critical Care, Santa Barbara Cottage Hospital, Santa Barbara, CA, USA.

Purpose: To evaluate the impact of pressure-regulated volume control (PRVC/VC+) use on delivered tidal volumes in patients with acute respiratory distress syndrome (ARDS) or at risk for ARDS.

Materials And Methods: Retrospective study of mechanically ventilated adult patients with severe sepsis or septic shock.

Results: A total of 272 patients were divided into patients with recognized ARDS, patients without ARDS, and patients with unrecognized ARDS. Read More

View Article and Full-Text PDF
November 2020

Effect of Two Regimens of Fluid Administration on Airway Edema in Prone-Position Surgery.

Anesth Essays Res 2020 Jul-Sep;14(3):467-473. Epub 2021 Mar 22.

Department of Anesthesiology and Perioperative Medicine, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia.

Background: Surgeries in prone position expose a patient to multitude of complications including laryngeal edema which may be related to the volume of fluid administered. Administering larger volumes of fluid intraoperatively may contribute to significant tissue edema, leading many anesthesiologists to practice a restrictive fluid infusion strategy. Although previous studies have compared fluid infusion strategies, changes in airway dimensions leading to airway edema have not been extensively investigated. Read More

View Article and Full-Text PDF

Supraglottic Airway Devices for Elective Pediatric Anesthesia: I-gel versus Air-Q, Which is the Best?

Anesth Essays Res 2020 Jul-Sep;14(3):461-466. Epub 2021 Mar 22.

Department of Anesthesia and ICU, Faculty of Medicine, Ain Shams University, Cairo, Egypt.

Objectives: The objectives of the study were to compare the insertion facility, the effect on hemodynamic parameters, and effective ventilation using I-gel versus Air-Q supraglottic airway devices (SADs) for pediatric patients undergoing short-duration surgical procedures.

Patients And Methods: One hundred and fifty children aged 3-10 years were randomly divided into two equal groups: Group I received I-gel and Group Q received Air-Q SAD. All patients were anesthetized by sevoflurane inhalation using a face mask without neuromuscular blockade. Read More

View Article and Full-Text PDF

Effect of total intravenous anesthesia or inhalation anesthesia on postoperative quality of recovery in patients undergoing total laparoscopic hysterectomy: A randomized controlled trial.

J Clin Anesth 2021 Oct 2;73:110374. Epub 2021 Jun 2.

Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, 209 Tongshan, Xuzhou, Jiangsu, China; Department of Anesthesiology, The Affiliated Hospital of Xuzhou Medical University, No.99 Huaihai West Road, Xuzhou, Jiangsu, China. Electronic address:

Study Objective: To investigate the effect of propofol-based total intravenous anesthesia (TIVA) or sevoflurane-based inhalation anesthesia on postoperative quality of recovery in patients undergoing total laparoscopic hysterectomy.

Design: A prospective randomized controlled trial.

Setting: An operating room, a postoperative recovery area, and a hospital ward. Read More

View Article and Full-Text PDF
October 2021