scholarly journals A method for measuring the molecular ratio of inhalation to exhalation and effect of inspired oxygen levels on oxygen consumption

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Koichiro Shinozaki ◽  
Yu Okuma ◽  
Kota Saeki ◽  
Santiago J. Miyara ◽  
Tomoaki Aoki ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Respiratory Quotient ◽  
New Method ◽  
Mechanically Ventilated ◽  
Oxygen Levels ◽  
Molecular Ratio ◽  
High Fraction ◽  
Fraction Of Inspired Oxygen ◽  
Inspired Oxygen

AbstractUsing a new method for measuring the molecular ratio (R) of inhalation to exhalation, we investigated the effect of high fraction of inspired oxygen (FIO2) on oxygen consumption (VO2), carbon dioxide generation (VCO2), and respiratory quotient (RQ) in mechanically ventilated rats. Twelve rats were equally assigned into two groups by anesthetics: intravenous midazolam/fentanyl vs. inhaled isoflurane. R, VO2, VCO2, and RQ were measured at FIO2 0.3 or 1.0. R error was ± 0.003. R was 1.0099 ± 0.0023 with isoflurane and 1.0074 ± 0.0018 with midazolam/fentanyl. R was 1.0081 ± 0.0017 at an FIO2 of 0.3 and 1.0092 ± 0.0029 at an FIO2 of 1.0. There were no differences in VCO2 among the groups. VO2 increased at FIO2 1.0, which was more notable when midazolam/fentanyl was used (isoflurane-FIO2 0.3: 15.4 ± 1.1; isoflurane-FIO2 1.0: 17.2 ± 1.8; midazolam/fentanyl-FIO2 0.3: 15.4 ± 1.1; midazolam/fentanyl-FIO2 1.0: 21.0 ± 2.2 mL/kg/min at STP). The RQ was lower at FIO2 1.0 than FIO2 0.3 (isoflurane-FIO2 0.3: 0.80 ± 0.07; isoflurane-FIO2 1.0: 0.71 ± 0.05; midazolam/fentanyl-FIO2 0.3: 0.79 ± 0.03; midazolam/fentanyl-FIO2 1.0: 0.59 ± 0.04). R was not affected by either anesthetics or FIO2. Inspired 100% O2 increased VO2 and decreased RQ, which might be more remarkable when midazolam/fentanyl was used.

scholarly journals Nebulized in-line endotracheal dornase alfa and albuterol administered to mechanically ventilated COVID-19 patients: a case series

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Andrew G. Weber ◽  
Alice S. Chau ◽  
Mikala Egeblad ◽  
Betsy J. Barnes ◽  
Tobias Janowitz
Keyword(s):  
Case Series ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Dornase Alfa ◽  
Extracellular Traps ◽  
Dnase 1 ◽  
Fraction Of Inspired Oxygen ◽  
Oxygen Requirements ◽  
Inspired Oxygen ◽  
Ventilated Patients

Abstract Background Mechanically ventilated patients with COVID-19 have a mortality of 24–53%, in part due to distal mucopurulent secretions interfering with ventilation. DNA from neutrophil extracellular traps (NETs) contribute to the viscosity of mucopurulent secretions and NETs are found in the serum of COVID-19 patients. Dornase alfa is recombinant human DNase 1 and is used to digest DNA in mucoid sputum. Here, we report a single-center case series where dornase alfa was co-administered with albuterol through an in-line nebulizer system. Methods Demographic and clinical data were collected from the electronic medical records of five mechanically ventilated patients with COVID-19—including three requiring veno-venous extracorporeal membrane oxygenation—treated with nebulized in-line endotracheal dornase alfa and albuterol, between March 31 and April 24, 2020. Data on tolerability and response were analyzed. Results The fraction of inspired oxygen requirements was reduced for all five patients after initiating dornase alfa administration. All patients were successfully extubated, discharged from hospital and remain alive. No drug-associated toxicities were identified. Conclusions Results suggest that dornase alfa will be well-tolerated by patients with severe COVID-19. Clinical trials are required to formally test the dosing, safety, and efficacy of dornase alfa in COVID-19, and several have been recently registered.

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

scholarly journals Knobmanship: Dialing Up Understanding of VAE Triggers

2021 ◽  
Vol 1 (S1) ◽  
pp. s80-s81
Author(s):  
Kelly Cawcutt ◽  
Mark Rupp ◽  
Lauren Musil
Keyword(s):  
Chart Review ◽  
Clinical Care ◽  
Trigger Points ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Review Period ◽  
Fraction Of Inspired Oxygen ◽  
Provider Bias ◽  
Inspired Oxygen ◽  
Ventilated Patients

Background: Mechanical ventilation is a lifesaving therapy for critically ill patients. Hospitals perform surveillance for the NHSN for ventilator-associated events (VAE) by monitoring mechanically ventilated patients for metrics that are generally thought to be objective and preventable and that lead to poor patient outcomes. The VAE definition is met in a stepwise manner; initially, a ventilator-associated condition (VAC) is triggered with an increase in positive end-expiratory pressure (PEEP, >3 cm H2O) or fraction of inspired oxygen (FIO2, 0.20 or 20 points) after a period of stability or improvement on the ventilator. We believe that many reported VAEs could be avoided by provider and respiratory therapy attention to “knobmanship.” We define knobmanship as knowledge of the VAE definition and trigger points combined with appropriate clinical care for mechanically ventilated patients while avoiding unnecessary triggering of the VAE definition by avoiding small unneeded changes in PEEP or FIO2. Methods: We performed a chart review of 283 patients who had a reported VAE to the NHSN between January 1, 2019, and December 31, 2020. We collected data including type of VAE, VAE triggering criteria, and clinical course. Results: Of the 283 VAEs, 59 were triggered by a PEEP increase from 5 to 8 with stable or decreasing FIO2. Of the 59 VAEs, 33 were VACs, 18 were infection-related ventilator- associated complications (IVACs), and 8 were possible ventilator-associated pneumonia (PVAP). Most of these transient changes in PEEP were deemed clinically unnecessary. A 21% reduction of VAEs reported to the NSHN over the 2-year review period could have been avoided by knobmanship. Conclusions: The VAE definition may often be triggered by provider bias to the ventilator settings rather than what the patient’s clinical-condition requires. Attention to knobmanship may result in substantial decrease in reported VAE.Funding: NoDisclosures: None

A high fraction of inspired oxygen may increase mortality in intubated trauma patients – A retrospective cohort study

Injury ◽  
2021 ◽  
Author(s):  
Josefine S. Baekgaard ◽  
Volkert Siersma ◽  
Rasmus Ejlersgaard Christensen ◽  
Camilla Ikast Ottosen ◽  
Katrine Bennett Gyldenkærne ◽  
...  
Keyword(s):  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Trauma Patients ◽  
High Fraction ◽  
Fraction Of Inspired Oxygen ◽  
Inspired Oxygen

Energy metabolism in hypnotic trance and sleep

1965 ◽  
Vol 20 (2) ◽  
pp. 308-310 ◽  
Author(s):  
Hrishikesh Jana
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Energy Metabolism ◽  
Respiratory Quotient ◽  
Metabolic Rates ◽  
Carbon Dioxide Elimination ◽  
Natural Sleep ◽  
Healthy Males

The energy metabolism of 14 healthy males was studied before and during a hypnotic trance in the basal state. Metabolic rates during the basal waking, the basal hypnotic trance and the basal sleep were also determined in three subjects for 3 consecutive days, respectively. It was observed that a hypnotic trance does not significantly influence the metabolic rates in a basal condition while natural sleep lowers the basal metabolic rates by 8.73%. hypnosis; oxygen consumption; carbon dioxide; elimination; respiratory quotient Submitted on April 7, 1964

Neuromuscular Blockade Does Not Decrease Oxygen Consumption or Energy Expenditure Beyond Sedation in the Mechanically Ventilated Child

1997 ◽  
Vol 12 (6) ◽  
pp. 321-323
Author(s):  
Robert L. Sheridan ◽  
Kathy Prelack ◽  
Stanislaw K. Szyfelbein
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Energy Expenditure ◽  
Neuromuscular Blockade ◽  
The Body ◽  
Controlled Study ◽  
Average Weight ◽  
Mechanically Ventilated ◽  
Significant Difference ◽  
Expired Gas

Minimizing the high oxygen consumption and energy expenditure of the critically ill is an important therapeutic goal. This study was done to determine if neuromuscular blockade decreases oxygen consumption or energy expenditure more than sedation alone in the mechanically ventilated child. Twelve burned children, with an average age of 5.1- 1.6 yrs, average weight of 22.8 − 6.5 kg, and average burn size of 28.3 − 5.8% of the body surface, scheduled for a planned surgical procedure under general anesthesia were enrolled in this prospective self-controlled study. In conjunction with planned operative procedures and using an intravenous anesthetic technique, the children underwent expired gas collection before and after neuromuscular blockade was induced. Expired gas was collected and analyzed for the fractional concentration of oxygen and carbon dioxide. Oxygen consumption (VO2), carbon dioxide production (VCO2), energy expenditure (EE), and respiratory quotient (RQ) were calculated. We found no significant difference in EE, VO2, VCO2, or RQ between the well-sedated and mechanically ventilated and the well-sedated, mechanically ventilated and paralyzed states. We therefore concluded that neuromuscular blockade does not decrease energy expenditure in the otherwise well-sedated burned child.

scholarly journals Conservative oxygen supplementation versus usual oxygen supplementation among septic medical intensive care units patients: A before-after investigation

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110169
Author(s):  
Ying Peng ◽  
Xiaoyan Yuan ◽  
Yi Zhang ◽  
Lei Wang
Keyword(s):  
Intensive Care ◽  
Partial Pressure ◽  
Outcome Measures ◽  
Partial Pressure Of Oxygen ◽  
Oxygen Supplementation ◽  
Number Of Patients ◽  
Target Values ◽  
High Fraction ◽  
Fraction Of Inspired Oxygen ◽  
Inspired Oxygen

Patients admitted in the intensive care unit (ICU) are always managed with excessive high fraction of inspired oxygen and have hyperoxia for a significant period of time, which has potential harms. The guidelines for the management of patients in ICUs do not provide the target values for partial pressure of oxygen or arterial oxyhemoglobin saturations. The study was a before-after investigation comparing two time periods in which different oxygenation strategies were applied. Data of oxygen control, outcome measures, and mortality of a total of 273 patients (>18 years) admitted at least for 2 days in ICUs and received treatment for the sepsis were retrospectively collected and analyzed. Patients were received usual oxygen supplementation (targeted partial pressure of oxygen: 150 mmHg; a high fraction of inspired oxygen: 0.4; UOS cohort; n = 142) or conservative oxygen supplementation (targeted partial pressure of oxygen: 70–100 mmHg; a high fraction of inspired oxygen as low as possible; COS cohort; n = 131). Mechanical ventilation-free hours were significantly higher for patients of COS cohort than those of UOS cohort (77.99 ± 21.26 h/patient vs 70.01 ± 23.57 h/patient, p = 0.016). ICUs length of stays of patients of COS cohort was fewer than those of UOS cohort (7.05 ± 2.13 days/patient vs 7.69 ± 2.43 days/patients, p = 0.016). The probability of survival of patients was higher among patients of COS cohort than those of UOS cohort ( p = 0.049). A higher number of patients from UOS cohort needed vasopressors than those from COS cohort (55 vs 35, p = 0.039). Conservative oxygen supplementation to maintain partial pressure of oxygen was improved outcome measures and decreases mortality as compared to that of usual oxygen supplementation. Level of Evidence: III. Technical Efficacy Stage: 4.

scholarly journals Factors associated with successful extubation following the use of systemic dexamethasone in ventilator dependent extremely preterm infants with bronchopulmonary dysplasia

2021 ◽  
Author(s):  
Kristin O'Connor ◽  
Cameron Hurst ◽  
Stacey Llewellyn ◽  
Mark Davies
Keyword(s):  
Bronchopulmonary Dysplasia ◽  
Binary Logistic Regression ◽  
Mechanically Ventilated ◽  
Extremely Preterm ◽  
Extremely Preterm Infants ◽  
Average Fraction ◽  
Fraction Of Inspired Oxygen ◽  
Oxygen Requirements ◽  
Inspired Oxygen ◽  
Successful Extubation

Objectives The aim of our study was to identify, in mechanically ventilated neonates <30 weeks GA with clinical evidence of bronchopulmonary dysplasia (BPD), factors likely to be predictive of a first course of systemic dexamethasone leading to extubation within 14 days and remaining extubated for at least 7 days. Methods We studied a retrospective cohort of neonates (23+0-29+6 weeks GA), with evidence of BPD, prescribed their first course of systemic dexamethasone to aid in extubation from mechanical ventilation. The data collected only pertained to the first course of dexamethasone for any given neonate, with the primary outcome of interest of successful extubation within 14 days (i.e., extubated within 14 days of starting dexamethasone and remaining extubated for at least seven days). Binary logistic regression was employed. Results A total of 287 neonates were included. Each additional week of GA at birth led to a 1.53 increase in the odds of successful extubation (95% CI 1.122-2.096, p<0.01). Higher average fraction of inspired oxygen (FiO2) requirements in the preceding 24 hours resulted in a 0.94 decrease in the odds of successful extubation (p<0.05) and higher mean airway pressure (MAP) resulted in 0.76 decrease in odds of successful extubation (p<0.01). Conclusions Mechanically ventilated neonates born at <30 week GA, with evidence of BPD requiring dexamethasone to facilitate extubation, had a lower likelihood of successful extubation by day 14 if at the time of commencing steroids they were less mature at birth, had higher MAPs and higher oxygen requirements.

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