Evaluation of pulse oximetry as a surrogate for PaO 2 in awake dogs breathing room air and anesthetized dogs on mechanical ventilation

2019 ◽  
Vol 29 (6) ◽  
pp. 622-629
Author(s):  
Kate S. Farrell ◽  
Kate Hopper ◽  
Laura A. Cagle ◽  
Steven E. Epstein
Keyword(s):  
Mechanical Ventilation ◽  
Pulse Oximetry ◽  
Anesthetized Dogs ◽  
Breathing Room

Comparison of canine cardiovascular response to inhaled and intraperitoneally infused CO

1985 ◽  
Vol 58 (2) ◽  
pp. 558-563 ◽  
Author(s):  
G. Gutierrez ◽  
H. H. Rotman ◽  
C. M. Reid ◽  
D. R. Dantzker
Keyword(s):  
Cardiovascular Response ◽  
Systemic Blood Pressure ◽  
Base Line ◽  
Peripheral Tissues ◽  
Significant Difference ◽  
Anesthetized Dogs ◽  
Peritoneal Space ◽  
Time Required ◽  
O2 Delivery ◽  
Breathing Room

We compared the hemodynamic and blood gas data from anesthetized dogs given 0.15% carbon monoxide (CO) to breathe (INH group) and from dogs injected with 100% CO intraperitoneally while breathing room air (ITP group). The animals were observed for a period of 150 min after reaching a level of 50% carboxyhemoglobin (HbCO). The time required to reach this level was similar for both groups, i.e., 102 +/- 54 and 90 +/- 21 min for the ITP and INH groups, respectively. The average HbCO% for the duration of the experiment was 58.3 +/- 2.4 and 62.9 +/- 1.5% for the ITP and INH groups, respectively. All the animals survived in each group. There was no significant difference in their hemodynamic response to CO, except for a higher mean systemic blood pressure in the INH group. This difference was also present during the base-line measurements, suggesting that it was not related to the effects of CO. Following the 150-min comparison period, we attempted to precipitate a terminal cardiovascular crisis by increasing the amount of CO given. The animals in the ITP group lived indefinitely as the result of a “plateau” effect in the level of HbCO%. The measured HbCO% level did not rise above 70% regardless of the amount of CO injected into the peritoneal space. Those in the inhalation group died with an average HbCO% of 80.0 +/- 3.5%. It is concluded that the toxic effect of CO is the result of impaired O2 delivery to the peripheral tissues.

In vivo regional diaphragm function in dogs

1989 ◽  
Vol 67 (2) ◽  
pp. 655-662 ◽  
Author(s):  
J. Sprung ◽  
C. Deschamps ◽  
R. D. Hubmayr ◽  
B. J. Walters ◽  
J. R. Rodarte
Keyword(s):  
Mechanical Ventilation ◽  
Chest Wall ◽  
Spontaneous Breathing ◽  
Considerable Variability ◽  
Diaphragm Function ◽  
Left Hemidiaphragm ◽  
Anesthetized Dogs ◽  
Abdominal Surface ◽  
Crural Diaphragm

A biplane videofluorographic system was used to track the position of metallic markers affixed to the abdominal surface of the left hemidiaphragm in supine anesthetized dogs. Regional shortening was determined from intermarker distances of rows of markers placed along muscle bundles in the ventral, middle, and dorsal regions of the costal diaphragm and of one row on the crural diaphragm. Considerable variability of regional shortening was seen in a given row, which was reproducible on repeat study in individual dogs but which differed between mechanical ventilation and spontaneous breathing. There were no consistent patterns among dogs. Regional shortening obtained from the change in length of rows extending from chest wall to central tendon showed no consistent differences among dogs during spontaneous breathing. At equal tidal volumes, all regions (except the ventral costal diaphragm) shortened more during spontaneous breathing than during mechanical ventilation.

A comparative evaluation of capnometry versus pulse oximetry during procedural sedation and analgesia on room air

CJEM ◽  
2010 ◽  
Vol 12 (05) ◽  
pp. 397-404 ◽  
Author(s):  
Marco L.A. Sivilotti ◽  
David W. Messenger ◽  
Janet van Vlymen ◽  
Paul E. Dungey ◽  
Heather E. Murray
Keyword(s):  
Carbon Dioxide ◽  
Pulse Oximetry ◽  
Pulse Oximeter ◽  
Oxygen Desaturation ◽  
Procedural Sedation And Analgesia ◽  
Respiratory Events ◽  
End Tidal Carbon Dioxide ◽  
Sedation And Analgesia ◽  
End Tidal ◽  
Breathing Room

ABSTRACTObjective:Important questions remain regarding how best to monitor patients during procedural sedation and analgesia (PSA). Capnometry can detect hypoventilation and apnea, yet it is rarely used in emergency patients. Even the routine practice of performing preoxygenation in low-risk patients is controversial, as supplementary oxygen can delay the detection of respiratory depression by pulse oximetry. The purpose of this study was to determine whether the capnometer or the pulse oximeter would first detect respiratory events in adults breathing room air.Methods:During a randomized clinical trial comparing fentanyl with low-dose ketamine for PSA with titrated propofol, patients were monitored using pulse oximetry and continuous oral–nasal sampled capnography. Supplemental oxygen was administered only for oxygen desaturation. Sedating physicians identified prespecified respiratory events, including hypoventilation (end-tidal carbon dioxide > 50 mm Hg, rise of 10 mm Hg from baseline or loss of waveform) and oxygen desaturation (pulse oximetry < 92%). These events and their timing were corroborated by memory data retrieved from the monitors.Results:Of 63 patients enrolled, 57% (36) developed brief oxygen desaturation at some point during the sedation. All responded to oxygen, stimulation or interruption of propofol. Measurements of end-tidal carbon dioxide varied substantially between and within patients before study intervention. Hypoventilation (19 patients, 30%) was only weakly associated with oxygen desaturation (crude odds ratio 1.4 [95% confidence interval 0.47 to 4.3]), and preceded oxygen desaturation in none of the 12 patients in whom both events occurred (median lag 1:50 m:ss [interquartile range 0:01 to 3:24 m:ss]).Conclusion:During PSA in adults breathing room air, desaturation detectable by pulse oximeter usually occurs before overt changes in capnometry are identified.

Vasopressin in plasma and cerebrospinal fluid of dogs during hypoxia or acidosis

1984 ◽  
Vol 247 (4) ◽  
pp. E449-E455 ◽  
Author(s):  
B. C. Wang ◽  
W. D. Sundet ◽  
K. L. Goetz
Keyword(s):  
Mechanical Ventilation ◽  
Cerebrospinal Fluid ◽  
Metabolic Acidosis ◽  
Synergistic Effects ◽  
Muscle Paralysis ◽  
Arterial Ph ◽  
Anesthetized Dogs ◽  
Vasopressin Secretion ◽  
Slow Intravenous Infusion ◽  
Mild Hypoxia

Hypoxia and hypercapnia have been shown to cause an increase in the concentration of vasopressin in plasma, but their effects on vasopressin in cerebrospinal fluid (CSF) are not known. In addition, the effect of metabolic acidosis on plasma and CSF vasopressin has not been reported. In this study, plasma and CSF vasopressin levels were measured in anesthetized dogs subjected to either hypoxia, hypercapnia, or metabolic acidosis. Rate and depth of respiration were closely regulated with the aid of muscle paralysis and mechanical ventilation. Vasopressin increased markedly in both plasma and CSF during severe hypoxia (10% O2) and during hypercapnia (10% CO2) but did not change during either mild (15% O2) or moderate (12.5% O2) hypoxia. Although mild hypoxia by itself did not affect either plasma or CSF vasopressin, it did potentiate the increase in plasma and CSF vasopressin that was induced by severe hypercapnia, thus suggesting that hypoxia and hypercapnia may exert synergistic effects on vasopressin secretion. Metabolic acidosis produced by slow intravenous infusion of 1 N hydrochloric acid decreased arterial pH to values comparable to those induced by hypercapnia and increased vasopressin in plasma; CSF vasopressin was unchanged. These results are consistent with the concept that the source of vasopressin secreted into plasma may be different from that secreted into CSF.

Ventilation-perfusion relationship during high-frequency ventilation

1984 ◽  
Vol 56 (2) ◽  
pp. 454-458 ◽  
Author(s):  
V. Brusasco ◽  
T. J. Knopp ◽  
E. R. Schmid ◽  
K. Rehder
Keyword(s):  
Mechanical Ventilation ◽  
High Frequency ◽  
Conventional Mechanical Ventilation ◽  
Regional Perfusion ◽  
High Frequency Ventilation ◽  
Regional Ventilation ◽  
Frequency Ventilation ◽  
Anesthetized Dogs

The efficiency of oxygenation and the uniformity of the distribution of regional ventilation (Vr) to regional perfusion (Qr) along the vertical and horizontal axes was compared in anesthetized dogs between conventional mechanical ventilation (CMV) and high-frequency ventilation (HFV) at 5.8, 15.0, and 29.8 Hz. Both CMV and HFV were adjusted to result in similar arterial CO2 tensions. The distribution of Vr/Qr during HFV at 5.8 Hz tended to be more uniform than during HFV at 15.0 or 29.8 Hz or during CMV. Consistent with this observation, arterial O2 tension (PaO2) tended to be higher during HFV at 5.8 Hz (means +/- SD, 90 +/- 9 Torr) than during HFV at 15.0 Hz (83 +/- 9 Torr) or 29.8 Hz (78 +/- 10 Torr); PaO2 was significantly higher during HFV at 5.8 Hz than during CMV (83 +/- 7 Torr).

Forehead Pulse Oximetry

2006 ◽  
Vol 105 (6) ◽  
pp. 1111-1116 ◽  
Author(s):  
Geeta S. Agashe ◽  
Joseph Coakley ◽  
Paul D. Mannheimer
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Healthy Volunteers ◽  
Trendelenburg Position ◽  
Hemoglobin Oxygen Saturation ◽  
Reading Accuracy ◽  
Reading Errors ◽  
Significant Difference ◽  
Consistent Performance ◽  
Breathing Room

Background This study investigated whether a tensioning headband that applies up to 20 mmHg pressure over a forehead pulse oximetry sensor could improve arterial hemoglobin oxygen saturation reading accuracy in presence of venous pooling and pulsations at the forehead site. Methods Healthy volunteers were studied breathing room air in supine and various levels of negative incline (Trendelenburg position) using the forehead sensor with the headband adjusted to its maximum and minimum recommended pressure limits. Saturation readings obtained from the forehead sensor with the subjects supine and the headband in place were used as a baseline to compare the effects of negative incline on reading accuracy when using and not using the headband. Occurrences of false low-saturation readings detected by forehead sensors were compared with those from digit sensors. Results No difference was observed between saturation readings obtained from the forehead sensor in supine and negative incline positions when the headband was applied. Forehead sensor readings obtained while subjects were inclined and the headband was not used were significantly lower (P < 0.05) than the supine readings. There was no statistically significant difference between the digit and forehead sensor in reporting false low-saturation readings when the headband was applied, regardless of body incline. Conclusions Application of up to 20 mmHg pressure on the forehead pulse oximetry sensor using an elastic tensioning headband significantly reduced reading errors and provided consistent performance when subjects were placed between supine and up to 15 degrees head-down incline (Trendelenburg position).

scholarly journals Optimization of choice of respiratory support the intensive care severe community-acquired pneumonia.

2018 ◽  
Vol 96 (2) ◽  
pp. 152-157
Author(s):  
Elena A. Borodulina ◽  
G. Yu. Chernogayeva ◽  
B. E. Borodulin ◽  
E. S. Vdoushkina ◽  
L. V. Povalyaeva ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Pulse Oximetry ◽  
Blood Gas Analysis ◽  
Community Acquired Pneumonia ◽  
Gas Analysis ◽  
Respiratory Support ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Arterial Blood Gas Analysis

The purpose of study is the optimization of the choice of method of respiratory support in patients with severe community-acquired pneumonia (CAP) on admission to intensive care unit (ICU) on the basis of acid-alkaline indicators and arterial blood gas analysis. Material and methods. Depending on the method of the choice of respiratory support two groups of 350 people were formed. The first group (n = 350) - by the results of pulse oximetry (SatO2). The second group (n = 350) - in terms of acid-base and arterial blood gas analysis (pH, PO2, PCO2). To determine hypoxemia, pulse oximetry (heart monitor GOLDWAY G40), acid-alkali and gas composition of arterial blood (gas analyzer «MEDICA EasyStat») were used. In the ICU there were conducted three types of respiratory support: 1) oxygen therapy via orinasal mask 2) non-invasive mechanical ventilation (respirators «VENTimotion 2» and «Bipap Vision») 3) mechanical ventilation («Engstrom Carestation»). The criterion of effectiveness: recovery performance pulse oximetry, acid-base balance, and arterial blood gas analysis, the presence of positive clinical dynamics. Results. Choice of method of respiratory support in the gas composition of blood allowed to expand the indications for use NIV as a method of respiratory support in the treatment of patients with severe CAP, to ensure timely transfer and reduce the time finding patients on mechanical ventilation, to avoid damage due to hypoxia bodies - «target» with the development of multiple organ failure, and thus 4.3 times to reduce mortality and length of stay in the ICU of 1.7.

scholarly journals Thinking Out-of-the-Box: A Non-Standard Application of Standard Pulse-Oximetry and Standard Near-Infrared Spectroscopy in a COVID-19 Patient

2020 ◽  
pp. 088506662096516
Author(s):  
Patrick Schober ◽  
Erik J. Lust ◽  
Leo M. A. Heunks ◽  
Lothar A. Schwarte
Keyword(s):  
Mechanical Ventilation ◽  
Infrared Spectroscopy ◽  
Pulse Oximetry ◽  
Prone Position ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Clinical Report ◽  
Muscle Tissues ◽  
Standard Application ◽  
Standard Pulse

Purpose: Purpose of this report is to describe the feasibility of lingual pulse oximetry and lingual near-infrared spectroscopy (NIRS) in a COVID-19 patient to assess lingual tissue viability after several days of mechanical ventilation in the prone position. Materials & Methods: In a COVID-19 ICU-patient, the tongue became grotesquely swollen, hardened and protruding from the oral cavity after 20 h of mechanical ventilation uninterrupted in the prone position. To assess the doubtful viability of the tongue, pulse-oximetric hemoglobin O2-saturation (SpO2; Nellcor, OxiMax MAX-NI, Covidien, MA, USA) and NIRS-based, regional tissue O2-saturation measurements (rSO2; SenSmart, Nonin, MN, USA) were performed at the tongue. Results: At the tongue, regular pulse-oximetric waveforms with a pulse-oximetric hemoglobin O2-saturation (SpO2) of 88% were recorded, i.e. only slightly lower than the SpO2 reading at the extremities at that time (90%). Lingual NIRS-based rSO2 measurements yielded stable tissue rSO2-values of 76-78%, i.e. values expected also in other adequately perfused and oxygenated (muscle-) tissues. Conclusion: Despite the alarming, clinical finding of a grotesquely swollen, rubber-hard tongue and clinical concerns on the adequacy of the tongue perfusion and oxygenation, our measurements of both arterial pulsatility (SpO2) and NIRS-based tissue oxygenation (rSO2) suggested adequate perfusion and oxygenation of the tongue, rendering non-vitality of the tongue, e.g. by lingual venous thrombosis, unlikely. To our knowledge, this is the first clinical report of lingual rSO2 measurement.

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