scholarly journals Effects of Breath-Holding Tests on PetCO2 and Arterial Blood Oxygenation in Men

2021 ◽  
Vol 6 (5) ◽  
pp. 423-429
Author(s):  
A. A. Pytel ◽  
◽  
S. O. Kovalenko
Keyword(s):  
Recovery Period ◽  
Statistical Processing ◽  
Blood Oxygenation ◽  
Breath Holding ◽  
Breath Hold ◽  
External Respiration ◽  
Group Iii ◽  
Arterial Blood ◽  
Individual Features ◽  
Level I

To evaluate the state of external respiration system, breath-holding tests are usually used. However, there are few studies of the peculiarities of the gas exchange in breath-holding with previous hyperventilation. The purpose of the study was to analyze the dynamics of changes in the PetCO2 level and arterial blood oxygenation during breath-holding tests with and without previous hyperventilation in healthy young men. Materials and methods. The СО2 level was recorded in the side stream on the Datex Normocap capnograph (Datex, Finland). This value was recorded for 5 minutes at rest, 5 minutes after half-breath hold, for 5 minutes of regulated breathing with a frequency of 30 cycles per minute, 5 minutes after half-breath hold. The capnogram, atmospheric pressure level and humidity were used to assess the level of СО2 at the end of exhalation (PetCO2), respiratory rate, the ratio of inspiratory duration to expiratory duration (Rie). Statistical processing of the results was performed by parametric methods. According to the method of sigmoid deviation, three groups of individuals were distinguished by the PetCO2 level: I – PetCO2 < 32.7 mmHg, II – PetCO2 – 32.7-36.2 mmHg, III – PetCO2 > 36.2 mmHg. Results and discussion. Breath-holding during the test after hyperventilation was significantly greater than in the first attempt (62.99±3.31 s and 33.78±2.24 s, p <0.001). Visual qualitative and quantitative analysis of capnograms and graphs of arterial blood oxygenation revealed significant inter-individual features of the reactions of these indicators to tests. Therefore, changes in PetCO2 were compared depending on its initial level. After the breath-holding test, the PetCO2 levels on average during the 5-minute recovery reliably decreased in groups II and III compared with I. During the test with hyperventilation, a natural significant increase in its level of reactivity was registered, most pronounced in group III (-13.48 mmHg, p <0.001). After the second breath-holding, there was a decrease in PetCO2 compared to the level after the first breath-holding in all groups. However, the level of HbO2 in the tests differed only in group II. Thus, after a breath-holding test, individuals with relatively low PetCO2 did not have its decrease in contrast to those with relatively medium and high levels. The use of hyperventilation potentiates these reactions before breath-holding, and aligns their level after a long recovery period in different groups. Conclusion. The study shows that breath-holding tests without and after hyperventilation significantly affect the level of CO2 stress and arterial blood oxygenation; the breath-holding test after hyperventilation potentiates the decrease in PetCO2 and HbO2 in arterial blood by increasing breath-holding time. There are significant individual features in the reactivity of such physiological parameters

scholarly journals Cerebrovascular reactivity assessment with O2-CO2 exchange ratio under brief breath hold challenge

2019 ◽  
Author(s):  
Suk Tak Chan ◽  
Karleyton C. Evans ◽  
Tian Yue Song ◽  
Juliett Selb ◽  
Andre van der Kouwe ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Partial Pressure ◽  
Cerebral Arteries ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Breath Holding ◽  
Breath Hold ◽  
Bold Signal ◽  
Signal Changes

AbstractHypercapnia during breath holding is believed to be the dominant driver behind the modulation of cerebral blood flow (CBF). Here we showed that the cerebrovascular responses to brief breath hold epochs were coupled not only with increased partial pressure of carbon dioxide (PCO2), but also with a decrease in partial pressure of oxygen (PO2). We used transcranial Doppler ultrasound to evaluate the CBF changes during breath holding by measuring the cerebral blood flow velocity (CBFv) in the middle cerebral arteries, a pair of cerebral arteries that supply most parts of the brain. The regional CBF changes during breath hold epochs were mapped with blood oxygenation level dependent (BOLD) signal changes as surrogate of CBF changes using functional magnetic resonance imaging (fMRI) technique. Given the interdependence of the dynamic changes between PCO2 and PO2, we found that the breath-by-breath O2-CO2 exchange ratio (bER), namely the ratio of changes in PO2 (ΔPO2) to changes in PCO2 (ΔPCO2) between end inspiration and end expiration, was superior to either ΔPO2 or ΔPCO2 alone in coupling with the changes of CBFv and BOLD signals under breath hold challenge. The regional cerebrovascular reactivity (CVR) results derived by regressing BOLD signal changes on bER under breath hold challenge resembled those derived by regressing BOLD signal changes on end-tidal partial pressure of CO2 (PETCO2) under exogenous CO2 challenge. Our findings provide a novel insight on the potential of using bER to better quantify CVR changes under breath hold challenge, although the physiological mechanisms of cerebrovascular changes underlying breath hold and exogenous CO2 challenges are potentially different.

Leucocyte depletion during cardiac surgery: a comparison of different filtration strategies

Perfusion ◽  
2003 ◽  
Vol 18 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Adrianus J de Vries ◽  
Y John Gu ◽  
Wendy J Post ◽  
Paulien Vos ◽  
Ietse Stokroos ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Blood Oxygenation ◽  
Low Flow ◽  
Control Group ◽  
Pressure Group ◽  
Group Iii ◽  
Arterial Blood ◽  
Clinical Difference ◽  
Group I ◽  
Scanning Electronmicroscopy

The results of leucocyte filtration during cardiac surgery are conflicting. This may be due to timing and duration of the filtration procedure, and to flow and pressure conditions in the filter. Therefore, we prospectively compared three major leucocyte filtration strategies in cardiac surgical patients. Forty patients were randomly divided into four groups. Group I: leucofiltration of arterial blood throughout cardiopulmonary bypass (CPB) (associated with high-flow and pressure gradients), Group II: leucofiltration of a part of the venous return blood in the re-warming phase during CPB (associated with intermediate flow, but high pressure), Group III: leucofiltration of residual heart-lung machine blood during transfusion into the patient after CPB (associated with low flow and low pressure), Group IV: control group without leucofiltration. We measured circulating leucocyte counts, plasma elastase levels and arterial blood oxygenation. Filters were postoperatively examined using scanning electronmicroscopy (SEM). Leucocyte counts increased over time and oxygenation decreased in all groups, without significant differences between the groups. SEM demonstrated extensive protein deposits and damaged leucocytes in the deeper layers of the filters from Group I. This was not observed in the filters from Group III. The postoperative plasma elastase levels increased in Groups II and IV and decreased in Groups I and III. In conclusion, we could not demonstrate a clinical difference among the three leucocyte depletion strategies. However, our laboratory results suggest that leucocyte filtration at low flow and pressure conditions is associated with less leucocyte damage and less release of elastase.

Man as a breath-hold diver

1988 ◽  
Vol 66 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Suk Ki Hong
Keyword(s):  
Cold Water ◽  
Decompression Sickness ◽  
Surrounding Medium ◽  
Subcutaneous Fat ◽  
Breath Holding ◽  
Breath Hold ◽  
Limiting Factor ◽  
Arterial Blood ◽  
Subcutaneous Fat Thickness ◽  
Body Heat

There are many thousands of both recreational and professional divers daily engaged in breath-hold diving throughout the world. The most widely known breath-hold divers are found among males and females in Japan and Korea, collectively called the ama. However, compared with many diving animals, man's ability as a breath-hold diver is very much limited. The average duration of a dive is 30–60 s, although one can dive for a period of up to 2–3 min. Usual depths of dive are 5–20 m. However, Jacques Mayol dove to 105 m in 1983, setting a new world record. It is still not clearly understood how one can reach such a depth without developing a pulmonary "squeeze." Human divers also display a mild but significant diving bradycardia which is often accompanied by cardiac arrhythmias. Although the cardiac output decreases slightly, the arterial blood pressure increases during breath holding. It has been suggested, but not unequivocally demonstrated that these cardiovascular changes observed during diving in man subserve to conserve O2 as in diving animals. Human divers descend to the bottom while retaining a considerable amount of air in the lung, thus allowing diffusion of N2 into the blood. As a result, human breath-hold divers can develop decompression sickness if they dive to deeper depths frequently enough. The major limiting factor for human divers is the loss of body heat to the surrounding medium (water) which has a high thermoconductivity. The subcutaneous fat thickness of human divers is much less than that in diving animals and thus human divers are at a great disadvantage. Although repetitive exposures to cold water stress are known to induce a significant cold acclimatization in man, these changes are rather ineffective in prolonging cold water diving time.

scholarly journals Role of cerebral blood flow in extreme breath holding

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Anthony R. Bain ◽  
Philip N. Ainslie ◽  
Ryan L. Hoiland ◽  
Chris K. Willie ◽  
David B. MacLeod ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Oral Administration ◽  
Blood Gases ◽  
Breath Holding ◽  
Breath Hold ◽  
Cyclooxygenase Inhibitor ◽  
Arterial Blood Gases ◽  
Arterial Blood

AbstractThe role of cerebral blood flow (CBF) on a maximal breath-hold (BH) in ultra-elite divers was examined. Divers (n = 7) performed one control BH, and one BH following oral administration of the non-selective cyclooxygenase inhibitor indomethacin (1.2 mg/kg). Arterial blood gases and CBF were measured prior to (baseline), and at BH termination. Compared to control, indomethacin reduced baseline CBF and cerebral delivery of oxygen (CDO

scholarly journals Large Lung Volumes Delay the Onset of the Physiological Breaking Point During Simulated Diving

2021 ◽  
Vol 12 ◽  
Author(s):  
Paul F. McCulloch ◽  
B. W. Gebhart ◽  
J. A. Schroer
Keyword(s):  
Lung Volume ◽  
Blood Gases ◽  
Breaking Point ◽  
Breath Holding ◽  
Breath Hold ◽  
Lung Volumes ◽  
Arterial Blood ◽  
Face Immersion ◽  
Residual Capacity ◽  
End Tidal

During breath holding after face immersion there develops an urge to breathe. The point that would initiate the termination of the breath hold, the “physiological breaking point,” is thought to be primarily due to changes in blood gases. However, we theorized that other factors, such as lung volume, also contributes significantly to terminating breath holds during face immersion. Accordingly, nine naïve subjects (controls) and seven underwater hockey players (divers) voluntarily initiated face immersions in room temperature water at Total Lung Capacity (TLC) and Functional Residual Capacity (FRC) after pre-breathing air, 100% O2, 15% O2 / 85% N2, or 5% CO2 / 95% O2. Heart rate (HR), arterial blood pressure (BP), end-tidal CO2 (etCO2), and breath hold durations (BHD) were monitored during all face immersions. The decrease in HR and increase in BP were not significantly different at the two lung volumes, although the increase in BP was usually greater at FRC. BHD was significantly longer at TLC (54 ± 2 s) than at FRC (30 ± 2 s). Also, with each pre-breathed gas BHD was always longer at TLC. We found no consistent etCO2 at which the breath holding terminated. BDHs were significantly longer in divers than in controls. We suggest that during breath holding with face immersion high lung volume acts directly within the brainstem to actively delay the attainment of the physiological breaking point, rather than acting indirectly as a sink to produce a slower build-up of PCO2.

scholarly journals Hemodynamic Changes after Visual Stimulation and Breath Holding Provide Evidence for an Uncoupling of Cerebral Blood Flow and Volume from Oxygen Metabolism

2008 ◽  
Vol 29 (1) ◽  
pp. 176-185 ◽  
Author(s):  
Manus J Donahue ◽  
Robert D Stevens ◽  
Michiel de Boorder ◽  
James J Pekar ◽  
Jeroen Hendrikse ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Blood Volume ◽  
Visual Stimulation ◽  
Functional Neuroimaging ◽  
Oxygen Metabolism ◽  
Blood Oxygenation ◽  
Breath Holding ◽  
Breath Hold ◽  
Bold Signal

Functional neuroimaging is most commonly performed using the blood-oxygenation-level-dependent (BOLD) approach, which is sensitive to changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and the cerebral metabolic rate of oxygen (CMRO2). However, the precise mechanism by which neuronal activity elicits a hemodynamic response remains controversial. Here, visual stimulation (14 secs flashing checkerboard) and breath-hold (4 secs exhale + 14 secs breath hold) experiments were performed in alternating sequence on healthy volunteers using BOLD, CBV-weighted, and CBF-weighted fMRI. After visual stimulation, the BOLD signal persisted for 33 ± 5 secs (n = 9) and was biphasic with a negative component (undershoot), whereas CBV and CBF returned to baseline without an undershoot at 20 ± 5 and 20 ± 3 secs, respectively. After breath hold, the BOLD signal returned to baseline (23 ±7 secs) at the same time ( P < 0.05) as CBV (21 ± 6 secs) and CBF (18 ±3 secs), without a poststimulus undershoot. These data suggest that the BOLD undershoot after visual activation reflects a persistent increase in CMRO2. These observations support the view that CBV and CBF responses elicited by neuronal activation are not necessarily coupled to local tissue metabolism.

Oxygen Fraction Adjustment According to Body Surface Area during Extracorporeal Circulation

2015 ◽  
Vol 18 (3) ◽  
pp. 098
Author(s):  
Cem Arıtürk ◽  
Serpil Ustalar Özgen ◽  
Behiç Danışan ◽  
Hasan Karabulut ◽  
Fevzi Toraman
Keyword(s):  
Body Temperature ◽  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Extracorporeal Circulation ◽  
Group Iii ◽  
Oxygen Fraction ◽  
Arterial Blood ◽  
Group I ◽  
Group Ii

<p class="p1"><span class="s1"><strong>Background:</strong> The inspiratory oxygen fraction (FiO<sub>2</sub>) is usually set between 60% and 100% during conventional extracorporeal circulation (ECC). However, this strategy causes partial oxygen pressure (PaO<sub>2</sub>) to reach hyperoxemic levels (&gt;180 mmHg). During anesthetic management of cardiothoracic surgery it is important to keep PaO<sub>2</sub> levels between 80-180 mmHg. The aim of this study was to assess whether adjusting FiO<sub>2</sub> levels in accordance with body temperature and body surface area (BSA) during ECC is an effective method for maintaining normoxemic PaO<sub>2</sub> during cardiac surgery.</span></p><p class="p1"><span class="s1"><strong>Methods:</strong> After approval from the Ethics Committee of the University of Acıbadem, informed consent was given from 60 patients. FiO<sub>2</sub> adjustment strategies applied to the patients in the groups were as follows: FiO<sub>2</sub> levels were set as 0.21 × BSA during hypothermia and 0.21 × BSA + 10 during rewarming in Group I; 0.18 × BSA during hypothermia and 0.18 × BSA + 15 during rewarming in Group II; and 0.18 × BSA during hypothermia and variable with body temperature during rewarming in Group III. Arterial blood gas values and hemodynamic parameters were recorded before ECC (T1); at the 10th minute of cross clamp (T2); when the esophageal temperature (OT) reached 34°C (T3); when OT reached 36°C (T4); and just before the cessation of ECC (T5).</span></p><p class="p1"><span class="s1"><strong>Results:</strong> Mean PaO<sub>2</sub> was significantly higher in Group I than in Group II at T2 and T3 (<em>P</em> = .0001 and <em>P</em> = .0001, respectively); in Group I than in Group III at T1 (<em>P</em> = .02); and in Group II than in Group III at T2, T3, and T4 <br /> (<em>P</em> = .0001 for all). </span></p><p class="p1"><span class="s1"><strong>Conclusion: </strong>Adjustment of FiO<sub>2</sub> according to BSA rather than keeping it at a constant level is more appropriate for keeping PaO<sub>2</sub> between safe level limits. However, since oxygen consumption of cells vary with body temperature, it would be appropriate to set FiO<sub>2</sub> levels in concordance with the body temperature in the <br /> rewarming period.</span></p>

scholarly journals Comparison of Compressed Sensing and Gradient and Spin-Echo in Breath-Hold 3D MR Cholangiopancreatography: Qualitative and Quantitative Analysis

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 634
Author(s):  
Weon Jang ◽  
Ji Soo Song ◽  
Sang Heon Kim ◽  
Jae Do Yang
Keyword(s):  
Image Quality ◽  
Compressed Sensing ◽  
Spin Echo ◽  
Contrast Ratio ◽  
Rank Test ◽  
Breath Holding ◽  
Breath Hold ◽  
Background Suppression ◽  
Time Saving ◽  
Noise Ratio

While magnetic resonance cholangiopancreatography (MRCP) is routinely used, compressed sensing MRCP (CS-MRCP) and gradient and spin-echo MRCP (GRASE-MRCP) with breath-holding (BH) may allow sufficient image quality with shorter acquisition times. This study qualitatively and quantitatively compared BH-CS-MRCP and BH-GRASE-MRCP and evaluated their clinical effectiveness. Data from 59 consecutive patients who underwent both BH-CS-MRCP and BH-GRASE-MRCP were qualitatively analyzed using a five-point Likert-type scale. The signal-to-noise ratio (SNR) of the common bile duct (CBD), contrast-to-noise ratio (CNR) of the CBD and liver, and contrast ratio between periductal tissue and the CBD were measured. Paired t-test, Wilcoxon signed-rank test, and McNemar’s test were used for statistical analysis. No significant differences were found in overall image quality or duct visualization of the CBD, right and left 1st level intrahepatic duct (IHD), cystic duct, and proximal pancreatic duct (PD). BH-CS-MRCP demonstrated higher background suppression and better visualization of right (p = 0.004) and left 2nd level IHD (p < 0.001), mid PD (p = 0.003), and distal PD (p = 0.041). Image quality degradation was less with BH-GRASE-MRCP than BH-CS-MRCP (p = 0.025). Of 24 patients with communication between a cyst and the PD, 21 (87.5%) and 15 patients (62.5%) demonstrated such communication on BH-CS-MRCP and BH-GRASE-MRCP, respectively. SNR, contrast ratio, and CNR of BH-CS-MRCP were higher than BH-GRASE-MRCP (p < 0.001). Both BH-CS-MRCP and BH-GRASE-MRCP are useful imaging methods with sufficient image quality. Each method has advantages, such as better visualization of small ducts with BH-CS-MRCP and greater time saving with BH-GRASE-MRCP. These differences allow diverse choices for visualization of the pancreaticobiliary tree in clinical practice.

Effect of lung volume on breath holding

1987 ◽  
Vol 62 (5) ◽  
pp. 1962-1969 ◽  
Author(s):  
W. A. Whitelaw ◽  
B. McBride ◽  
G. T. Ford
Keyword(s):  
Lung Volume ◽  
Hold Time ◽  
Esophageal Pressure ◽  
Breath Holding ◽  
Breath Hold ◽  
Pressure Waves ◽  
Expiratory Muscle ◽  
Inspiratory Muscles ◽  
Consistent Change ◽  
Rhythmic Contractions

The mechanism by which large lung volume lessens the discomfort of breath holding and prolongs breath-hold time was studied by analyzing the pressure waves made by diaphragm contractions during breath holds at various lung volumes. Subjects rebreathed a mixture of 8% CO2–92% O2 and commenced breath holding after reaching an alveolar plateau. At all volumes, regular rhythmic contractions of inspiratory muscles, followed by means of gastric and pleural pressures, increased in amplitude and frequency until the breakpoint. Expiratory muscle activity was more prominent in some subjects than others, and increased through each breath hold. Increasing lung volume caused a delay in onset and a decrease in frequency of contractions with no consistent change in duty cycle and a decline in magnitude of esophageal pressure swings that could be accounted for by force-length and geometric properties. The effect of lung volume on the timing of contractions most resembled that of a chest wall reflex and is consistent with the hypothesis that the contractions are a major source of dyspnea in breath holding.

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