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end tidal expired co2

Weishuai Bian, Wei Chen, Yangong Chao, Lan Wang, Liming Li, Jian Guan, Xuefeng Zang, Jie Zhen, Bo Sheng, Xi Zhu
This study aimed to apply the dead space fraction [ratio of dead space to tidal volume (VD/VT)] to titrate the optimal positive end-expiratory pressure (PEEP) in a swine model of acute respiratory distress syndrome (ARDS). Twelve swine models of ARDS were constructed. A lung recruitment maneuver was then conducted and the PEEP was set at 20 cm H2O. The PEEP was reduced by 2 cm H2O every 10 min until 0 cm H2O was reached, and VD/VT was measured after each decrement step. VD/VT was measured using single-breath analysis of CO2, and calculated from arterial CO2 partial pressure (PaCO2) and mixed expired CO2 (PeCO2) using the following formula: VD/VT = (PaCO2 - PeCO2)/PaCO2...
April 2017: Experimental and Therapeutic Medicine
David Mangin, Emilie Bequignon, Francoise Zerah-Lancner, Daniel Isabey, Bruno Louis, Serge Adnot, Jean-François Papon, André Coste, Laurent Boyer, Marie Devars du Mayne
OBJECTIVES/HYPOTHESIS: Patients with empty nose syndrome (ENS) following turbinate surgery often complain about breathing difficulties. We set out to determine if dyspnea in patients with ENS was associated with hyperventilation syndrome (HVS). We hypothesized that lower airway symptoms in ENS could be explained by HVS. STUDY DESIGN: Observational prospective study. METHODS: All consecutive patients referred to our center for ENS over 1 year were invited to participate...
April 13, 2017: Laryngoscope
Steffen Wirth, Sebastian Springer, Johannes Spaeth, Silke Borgmann, Ulrich Goebel, Stefan Schumann
BACKGROUND: Traditionally, mechanical ventilation is achieved via active lung inflation during inspiration and passive lung emptying during expiration. By contrast, the novel FLEX (FLow-controlled EXpiration) ventilator mode actively decreases the rate of lung emptying. We investigated whether FLEX can be used during intraoperative mechanical ventilation of lung-healthy patients. METHODS: In 30 adult patients scheduled for neurosurgical procedures, we studied respiratory system mechanics, regional ventilation, oxygenation, and hemodynamics during ventilation with and without FLEX at positive end-expiratory pressure (PEEP) of 5 and 7 cm H2O...
March 31, 2017: Anesthesia and Analgesia
Monica Rocco, Luigi Maggi, Giorgio Ranieri, Giovanni Ferrari, Cesare Gregoretti, Giorgio Conti, Roberto A DE Blasi
BACKGROUND: The diaphragm is the most important respiratory muscle in humans, and the close relationship between inspired volume and diaphragmatic movement in normal subjects has led to investigations into diaphragmatic activity using ultrasound, during spontaneous breathing and sedative drug infusion. METHODS: A total of 36 consecutive patients undergoing diagnostic procedures under deep propofol sedation were studied. Ultrasound measurements included the following: diaphragmatic thickening end-inspiration (TEI) and end-expiration (TEE)...
March 2017: Minerva Anestesiologica
Shreyas Harita, Patrick W Stroman
PURPOSE: Resting-state functional MRI (rs-fMRI) has been used to investigate networks within the cortex, but its use in the brainstem (BS) and spinal cord (SC) has been limited. This region presents challenges for fMRI, partly because of sources of physiological noise. This study aims to quantify noise contributions to rs-fMRI, and to obtain evidence of resting-state blood oxygenation level-dependent (BOLD) fluctuations. METHODS: Resting-state-fMRI data were obtained from the BS/SC in 16 participants, at 3 Tesla, with T2 -weighted single-shot fast spin-echo imaging...
January 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Justin S Phillips, Lance P Pangilinan, Earl R E Mangalindan, Joseph L Booze, Richard H Kallet
BACKGROUND: Accurately measuring the partial pressure of end-tidal CO2 (PETCO2 ) in non-intubated patients is problematic due to dilution of expired CO2 at high O2 flows and mask designs that may either cause CO2 rebreathing or inadequately capture expired CO2. We evaluated the performance of 2 capnographic O2 masks (Cap-ONE and OxyMask) against a clinically expedient method using a standard O2 mask with a flow-directed nasal cannula used for capnography (CapnoLine) in a spontaneous breathing model of an adult and child under conditions of normal ventilation, hypoventilation, and hyperventilation...
January 2017: Respiratory Care
Natalie Napolitano, Akira Nishisaki, Hayley S Buffman, Jessica Leffelman, Matthew R Maltese, Vinay M Nadkarni
BACKGROUND: Partial pressure of end-tidal carbon dioxide (PETCO2 ) monitoring in children is important to detect apnea or hypopnea early to intervene before hypoxemia develops. Monitoring PETCO2 in children without a tracheal tube is challenging. To improve PETCO2 measurement accuracy in a commercially available mask with a mainstream CO2 detector, we implemented design changes with deform-and-hold shaping technology and anterior-posterior adjustment of the expiratory gas flow cup. METHODS: Two sizes of redesigned face masks (small for 7-20 kg, medium for 10-40 kg) were evaluated...
January 2017: Respiratory Care
Andreas Fahlman, Johnny Madigan
We measured esophageal pressures (n = 4), respiratory flow rates (n = 5), and expired O2 and CO2 (n = 4) in five adult Patagonia sea lions (Otaria flavescens, body mass range 94.3-286.0 kg) during voluntary breaths while laying down out of water. The data were used to estimate the dynamic specific lung compliance (sCL), the O2 consumption rate ([Formula: see text]O2) and CO2 production rates ([Formula: see text]CO2) during rest. Our results indicate that the resting tidal volume in Patagonia sea lions is approximately 47-73% of the estimated total lung capacity...
2016: Frontiers in Physiology
Yi Liu, Jing-Sheng Lou, Wei-Dong Mi, Wei-Xiu Yuan, Qiang Fu, Min Wang, Jing Qu
BACKGROUND: The settings of mechanical ventilation, like tidal volume (VT), occasionally need to be adjusted in the process of anesthesia for some special reasons. The aim of this study was therefore to assess the relationship between pulse pressure variations (PPVs) in different settings of VT in anesthetized healthy patients under mechanical ventilation. METHODS: Sixty nine ASA I-II patients scheduled for gastrointestinal surgery under general anesthesia were included in this prospective study...
September 8, 2016: BMC Anesthesiology
L W Sturesson, G Malmkvist, S Allvin, M Collryd, M Bodelsson, B Jonson
BACKGROUND: In acute lung injury, CO2 exchange is enhanced by prolonging the volume-weighted mean time for fresh gas to mix with resident alveolar gas, denoted mean distribution time (MDT), and by increasing the flow rate immediately before inspiratory flow interruption, end-inspiratory flow (EIF). The objective was to study these effects in human subjects without lung disease and to analyse the results with respect to lung-protective ventilation of healthy lungs. METHODS: During preparation for intracranial surgery, the lungs of eight subjects were ventilated with a computer-controlled ventilator, allowing breath-by-breath modification of the inspiratory flow pattern...
August 2016: British Journal of Anaesthesia
S E Rees, S Larraza, N Dey, S Spadaro, J B Brohus, R W Winding, C A Volta, D S Karbing
Incomplete expiration of tidal volume can lead to dynamic hyperinflation and auto-PEEP. Methods are available for assessing these, but are not appropriate for patients with respiratory muscle activity, as occurs in pressure support. Information may exist in expiratory flow and carbon dioxide measurements, which, when taken together, may help characterize dynamic hyperinflation. This paper postulates such patterns and investigates whether these can be seen systematically in data. Two variables are proposed summarizing the number of incomplete expirations quantified as a lack of return to zero flow in expiration (IncExp), and the end tidal CO2 variability (varETCO2), over 20 breaths...
June 25, 2016: Journal of Clinical Monitoring and Computing
Silvia Maria Doria da Silva, Ilma Aparecida Paschoal, Eduardo Mello De Capitani, Marcos Mello Moreira, Luciana Campanatti Palhares, Mônica Corso Pereira
BACKGROUND: Computed tomography (CT) phenotypic characterization helps in understanding the clinical diversity of chronic obstructive pulmonary disease (COPD) patients, but its clinical relevance and its relationship with functional features are not clarified. Volumetric capnography (VC) uses the principle of gas washout and analyzes the pattern of CO2 elimination as a function of expired volume. The main variables analyzed were end-tidal concentration of carbon dioxide (ETCO2), Slope of phase 2 (Slp2), and Slope of phase 3 (Slp3) of capnogram, the curve which represents the total amount of CO2 eliminated by the lungs during each breath...
2016: International Journal of Chronic Obstructive Pulmonary Disease
X Zhang, P Wargocki, Z Lian
Twenty-five subjects were exposed to different levels of carbon dioxide (CO2 ) and bioeffluents. The ventilation rate was set high enough to create a reference condition of 500 ppm CO2 with subjects present; additional CO2 was then added to supply air to reach levels of 1000 or 3000 ppm, or the ventilation rate was reduced to allow metabolically generated CO2 to reach the same two levels (bioeffluents increased as well). Heart rate, blood pressure, end-tidal CO2 (ETCO2 ), oxygen saturation of blood (SPO2 ), respiration rate, nasal peak flow, and forced expiration were monitored, and the levels of salivary α-amylase and cortisol were analyzed...
January 2017: Indoor Air
Randy F Crossland, Alex Mitchell, Antoni R Macko, James K Aden, James E Campbell, Forest R Sheppard
BACKGROUND: Heart rate (HR), systolic blood pressure (SBP) and mean arterial pressure (MAP) are traditionally used to guide patient triage and resuscitation; however, they correlate poorly to shock severity. Therefore, improved acute diagnostic capabilities are needed. Here, we correlated acute alterations in tissue oxygen saturation (StO2) and end-tidal carbon dioxide (ETCO2) to mortality in a rhesus macaque model of uncontrolled hemorrhage. METHODS: Uncontrolled hemorrhage was induced in anesthetized rhesus macaques by a laparoscopic 60% left-lobe hepatectomy (T = 0 minute)...
April 2016: Journal of Trauma and Acute Care Surgery
Elliott Shang-shun Li, Po-Yin Cheung, Megan O'Reilly, Joseph LaBossiere, Tze-Fun Lee, Shaun Cowan, David L Bigam, Georg Marcus Schmölzer
BACKGROUND: End-tidal CO2 (ETCO2), partial pressure of exhaled CO2 (PECO2), and volume of expired CO2 (VCO2) can be continuously monitored non-invasively to reflect pulmonary ventilation and perfusion status. Although ETCO2 ≥14 mmHg has been shown to be associated with return of an adequate heart rate in neonatal resuscitation and quantifying the PECO2 has the potential to serve as an indicator of resuscitation quality, there is little information regarding capnometric measurement of PECO2 and ETCO2 in detecting return of spontaneous circulation (ROSC) and survivability in asphyxiated neonates receiving cardiopulmonary resuscitation (CPR)...
2016: PloS One
Clara Conde Ruiz, Inga-Catalina Cruz Benedetti, Isabelle Guillebert, Karine Genevieve Portier
This prospective blinded randomized study aimed to determine whether the timing of morphine and phenylbutazone administration affects the breathing response to skin incision, recovery quality, behavior, and cardiorespiratory variables in horses undergoing fetlock arthroscopy. Ten Standardbred horses were premedicated with acepromazine (0.04 mg kg(-1) IM) and romifidine (0.04 mg kg(-1) IV). Anesthesia was induced with diazepam (0.05 mg kg(-1)) and ketamine (2.2 mg kg(-1)) IV at T0. Horses in group PRE (n = 5) received morphine (0...
2015: Frontiers in Veterinary Science
Marie-Cécile Nierat, Anna L Hudson, Joël Chaskalovic, Thomas Similowski, Louis Laviolette
In awake humans, breathing depends on automatic brainstem pattern generators. It is also heavily influenced by cortical networks. For example, functional magnetic resonance imaging and electroencephalographic data show that the supplementary motor area becomes active when breathing is made difficult by inspiratory mechanical loads like resistances or threshold valves, which is associated with perceived respiratory discomfort. We hypothesized that manipulating the excitability of the supplementary motor area with repetitive transcranial magnetic stimulation would modify the breathing pattern response to an experimental inspiratory load and possibly respiratory discomfort...
2015: Frontiers in Physiology
Ling Liu, Daijiro Takahashi, Haibo Qui, Arthur S Slutsky, Christer Sinderby, Jennifer Beck
BACKGROUND: During conventional Neurally Adjusted Ventilatory Assist (NAVA), the electrical activity of the diaphragm (EAdi) is used for triggering and cycling-off inspiratory assist, with a fixed PEEP (so called "Triggered Neurally Adjusted Ventilatory Assist" or "tNAVA"). However, significant post-inspiratory activity of the diaphragm can occur, believed to play a role in maintaining end-expiratory lung volume. Adjusting pressure continuously, in proportion to both inspiratory and expiratory EAdi (Continuous NAVA, or cNAVA), would not only offer inspiratory assist for tidal breathing, but also may aid in delivering a "neurally adjusted PEEP", and more specific breath-by-breath unloading...
2015: BMC Anesthesiology
Odette O, Sarah M Churgin, Kurt K Sladky, Lesley J Smith
Inland bearded dragons (Pogona vitticeps, n=6) were anesthetized for 1 hr using isoflurane in either 100% oxygen or 21% oxygen (FI 21; medical-grade room air). Parameters of anesthetic depth were recorded throughout both induction and recovery by an observer blinded to the fraction of inspired oxygen (FiO2), including the loss and return of withdrawal and righting reflexes, muscle tone, ability to intubate or extubate, and return to spontaneous respiration. Physiologic data were recorded every 5 min throughout the anesthetic procedures, including heart rate, body temperature, end-tidal CO2, hemoglobin oxygen saturation (SpO2), and percent expired isoflurane...
September 2015: Journal of Zoo and Wildlife Medicine: Official Publication of the American Association of Zoo Veterinarians
Jeroen J van Vonderen, Gianluca Lista, Francesco Cavigioli, Stuart B Hooper, Arjan B te Pas
OBJECTIVE: To measure tidal volume, plethysmography changes and gas exchange during respiratory support at birth. DESIGN: The following parameters were measured: (1) expired tidal volumes (Vte (mL/kg)) using respiratory function monitoring, (2) changes in plethysmography (AU/kg) per breath using respiratory inductance plethysmography (bands placed around rib cage (RC) and abdomen (AB)) and (3) expired CO2 (ECO2) levels using a volumetric CO2 monitor. For respiratory support, a T-piece resuscitator and facemask were used with peak inspiratory pressure (PIP) 25 cm H2O and positive end expiratory pressure 5 cm H2O...
November 2015: Archives of Disease in Childhood. Fetal and Neonatal Edition
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