An increase in breath-hold time appearing after breath-holding

1968 ◽  
Vol 4 (1) ◽  
pp. 73-77 ◽  
Author(s):  
J.R. Heath ◽  
C.J. Irwin
Keyword(s):  
Hold Time ◽  
Breath Holding ◽  
Breath Hold

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.

scholarly journals Effect of gravity on aerosol dispersion and deposition in the human lung after periods of breath holding

2000 ◽  
Vol 89 (5) ◽  
pp. 1787-1792 ◽  
Author(s):  
Chantal Darquenne ◽  
Manuel Paiva ◽  
G. Kim Prisk
Keyword(s):  
Flow Rate ◽  
Turbulent Mixing ◽  
Direct Evidence ◽  
Human Lung ◽  
Hold Time ◽  
Aerosol Deposition ◽  
Breath Holding ◽  
Breath Hold ◽  
Constant Flow Rate ◽  
Aerosol Dispersion

To determine the extent of the role that gravity plays in dispersion and deposition during breath holds, we performed aerosol bolus inhalations of 1-μm-diameter particles followed by breath holds of various lengths on four subjects on the ground (1G) and during short periods of microgravity (μG). Boluses of ∼70 ml were inhaled to penetration volumes (Vp) of 150 and 500 ml, at a constant flow rate of ∼0.45 l/s. Aerosol concentration and flow rate were continuously measured at the mouth. Aerosol deposition and dispersion were calculated from these data. Deposition was independent of breath-hold time at both Vp in μG, whereas, in 1G, deposition increased with increasing breath hold time. At Vp = 150 ml, dispersion was similar at both gravity levels and increased with breath hold time. At Vp = 500 ml, dispersion in 1G was always significantly higher than in μG. The data provide direct evidence that gravitational sedimentation is the main mechanism of deposition and dispersion during breath holds. The data also suggest that cardiogenic mixing and turbulent mixing contribute to deposition and dispersion at shallow Vp.

Measurement of temporal changes in DLSBCO-3EQ from small alveolar samples in normal subjects

1994 ◽  
Vol 76 (4) ◽  
pp. 1494-1501 ◽  
Author(s):  
G. R. Soparkar ◽  
J. T. Mink ◽  
B. L. Graham ◽  
D. J. Cotton
Keyword(s):  
Hold Time ◽  
Normal Subjects ◽  
Gas Diffusion ◽  
Phase Iii ◽  
Mixing Efficiency ◽  
Breath Holding ◽  
Breath Hold ◽  
Inspiratory Capacity ◽  
Ventilation Inhomogeneity ◽  
Single Breath

The dynamic changes in CO concentration [CO] during a single breath could be influenced by topographic inhomogeneity in the lung or by peripheral inhomogeneity due to a gas mixing resistance in the gas phase of the lung or to serial gradients in gas diffusion. Ten healthy subjects performed single-breath maneuvers by slowly inhaling test gas from functional residual capacity to one-half inspiratory capacity and slowly exhaling to residual volume with target breath-hold times of 0, 1.5, 3, 6, and 9 s. We calculated the three-equation single-breath diffusing capacity of the lung for CO (DLSBCO-3EQ) from the mean [CO] in both the entire alveolar gas sample and in four successive equal alveolar gas samples. DLSBCO-3EQ from the entire alveolar gas sample was independent of breath-hold time. However, with 0 s of breath holding, from early alveolar gas samples DLSBCO-3EQ was reduced and from late alveolar gas samples it was increased. With increasing breath-hold time, DLSBCO-3EQ from the earliest alveolar gas sample rapidly increased, whereas from the last alveolar gas sample it rapidly decreased such that all values from the small alveolar gas samples approached DLSBCO-3EQ from the entire alveolar sample. These changes correlated with ventilation inhomogeneity, as measured by the phase III He concentration slope and the mixing efficiency, and were larger for maneuvers with inspired volumes to one-half inspiratory capacity vs. total lung capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Single-breath breath-holding estimate of pulmonary blood flow in man: comparison with direct Fick cardiac output

1989 ◽  
Vol 76 (6) ◽  
pp. 673-676 ◽  
Author(s):  
A. H. Kendrick ◽  
A. Rozkovec ◽  
M. Papouchado ◽  
J. West ◽  
G. Laszlo
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Pulmonary Blood Flow ◽  
Hold Time ◽  
Normal Subjects ◽  
Breath Holding ◽  
Breath Hold ◽  
Single Breath ◽  
Significant Difference ◽  
Cardiac Disorders

1. Resting pulmonary blood flow (Q.), using the uptake of the soluble inert gas Freon-22 and an indirect estimate of lung tissue volume, has been estimated during breath-holding (Q.c) and compared with direct Fick cardiac output (Q.f) in 16 patients with various cardiac disorders. 2. The effect of breath-hold time was investigated by comparing Q.c estimated using 6 and 10 s of breath-holding in 17 patients. Repeatability was assessed by duplicate measurements of Q.c in the patients and in six normal subjects. 3. Q.c tended to overestimate Q.f, the bias and error being 0.09 l/min and 0.59, respectively. The coefficient of repeatability for Q.c in the patients was 0.75 l/min and in the normal subjects was 0.66 1/min. For Q.f it was 0.72 l/min. There was no significant difference in Q.c measured at the two breath-hold times. 4. The technique is simple to perform, and provides a rapid estimate of Q., monitoring acute and chronic changes in cardiac output in normal subjects and patients with cardiac disease.

Maximum effort breath-hold times for males and females of similar pulmonary capacities during sudden face-only immersion at water temperatures from 0 to 33 °C

2006 ◽  
Vol 31 (5) ◽  
pp. 549-556 ◽  
Author(s):  
Ollie Jay ◽  
Matthew D. White
Keyword(s):  
Water Temperature ◽  
Hold Time ◽  
Breath Holding ◽  
Breath Hold ◽  
Main Effect ◽  
Before And After ◽  
Maximum Effort ◽  
Males And Females ◽  
End Tidal ◽  
Air Control

For non breath-hold-trained males and females matched for pulmonary capacity and body size, the effects of sex, water temperature, and end-tidal gas tensions were studied for their potential influences on breath-holding ability. Maximum breath-hold time (BHTmax) was measured a total of 546 times in 13 males and 13 females, each repeating 3 trials of sudden face immersion (i.e., no prior hyperventilation) in water at 0, 5, 10, 15, 20, and 33 °C and in an air control condition (AIR). End-tidal carbon dioxide (PETCO2) and oxygen (PETO2) gas tensions were measured before and after breath-holding in a subset of 11 males and 11 females. For BHTmax there was no main effect of sex (p = 0.20), but there was a main effect of immersion condition (p < 0.001). Relative to pre-immersion rest values, end-tidal gas tensions were significantly higher in males than in females (p ≤ 0.05) and significantly lower at decreased water temperatures relative to AIR (p ≤ 0.05). In conclusion, for these matched groups (i) sex did not influence BHTmax; (ii) irrespective of sex, decreases in water temperature at 0, 5, 10, and 15 °C gave proportionate decreases of BHTmax; (iii) significantly greater deviations in both PETCO2 and PETO2 following breath-holding were evident in males relative to females; and (iv) irrespective of sex, there were significantly smaller changes in both PETCO2 and PETO2 at lower water temperatures relative to AIR, with or without removing the variance due to breath holding.

Voluntary breath holding in the obese

1987 ◽  
Vol 62 (6) ◽  
pp. 2371-2376 ◽  
Author(s):  
A. N. Hurewitz ◽  
M. G. Sampson
Keyword(s):  
Body Weight ◽  
Important Determinant ◽  
Hold Time ◽  
Breath Holding ◽  
Breath Hold ◽  
O2 Consumption ◽  
Excellent Correlation ◽  
Residual Capacity ◽  
Arterial O2 Saturation ◽  
Voluntary Breath Holding

Alveolar gas tensions and arterial O2 saturation (Sao2) during a voluntary breath hold at functional residual capacity (FRC) were examined in 13 healthy seated subjects. An excellent correlation (r = 0.80) was found between the fall of alveolar O2 tensions (delta PETo2) and body weight, expressed as the ratio of weight to height (wt/ht, kg/cm). An even greater correlation (r = 0.89) was found between delta PETo2 and the ratio of breath-hold time X O2 consumption/FRC. Alveolar Po2 decreased to 70 mmHg in the obese group after just 15 s of apnea, whereas this degree of hypoxia did not occur in the nonobese until the breath hold was sustained for 30 s. This variable rate of fall of alveolar Po2 during a breath hold can be ascribed to the changes of O2 consumption (Vo2) and FRC associated with changing body weight. In the obese, Vo2/FRC was twice as large as in the nonobese, thus accounting for the differences of breath-hold time needed to obtain the same alveolar Po2. Sao2 measured at the end of the breath hold was the same as that value predicted from the reduction of PETo2. This suggests that the fall of alveolar Po2 can entirely account for the observed fall of O2 saturation and that venous admixture had not increased during the 15-s apnea. In patients with sleep apnea, the ratio of Vo2/(initial lung volume) may also be an important determinant of the severity of hypoxemia observed.

Effect of breath-hold time on DLCO(SB) in patients with airway obstruction

1985 ◽  
Vol 58 (4) ◽  
pp. 1319-1325 ◽  
Author(s):  
B. L. Graham ◽  
J. T. Mink ◽  
D. J. Cotton
Keyword(s):  
Hold Time ◽  
Phase Iii ◽  
Breath Holding ◽  
Breath Hold ◽  
Single Breath ◽  
Incomplete Mixing ◽  
Capillary Membrane ◽  
Phase Iii Slope ◽  
Alveolar Capillary ◽  
Short Breath

The single-breath diffusing capacity of the lung for CO [DLCO(SB)] is considered a measure of the conductance of CO across the alveolar-capillary membrane and its binding with hemoglobin. Although incomplete mixing of inspired gas with alveolar gas could theoretically influence overall diffusion, conventional calculations of DLCO(SB) spuriously overestimate DLCO(SB) during short breath-holding periods when incomplete mixing of gas within the lung might have the greatest effect. Using the three-equation method to calculate DLCO(SB) which analytically accounts for changes in breath-hold time, we found that DLCO(SB) did not change with breath-hold time in control subjects but increased with increasing breath-hold time in both patients with asthma and patients with emphysema. The increase in DLCO(SB) with increasing breath-hold time correlated with the phase III slope of the single-breath N2 washout curve. We suggest that in patients with ventilation maldistribution, DLCO(SB) may be decreased for the shorter breath-hold maneuvers because overall diffusion is limited by the reduced transport of CO from the inspired gas through the alveolar gas prior to alveolar-capillary gas exchange.

scholarly journals Standardisation and application of the single-breath determination of nitric oxide uptake in the lung

2017 ◽  
Vol 49 (2) ◽  
pp. 1600962 ◽  
Author(s):  
Gerald S. Zavorsky ◽  
Connie C.W. Hsia ◽  
J. Michael B. Hughes ◽  
Colin D.R. Borland ◽  
Hervé Guénard ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Hold Time ◽  
Haemoglobin Concentration ◽  
Specific Conductance ◽  
Breath Holding ◽  
Breath Hold ◽  
Diffusing Capacity ◽  
Detection Range ◽  
Single Breath ◽  
Alveolar Oxygen

Diffusing capacity of the lung for nitric oxide (DLNO), otherwise known as the transfer factor, was first measured in 1983. This document standardises the technique and application of single-breathDLNO. This panel agrees that 1) pulmonary function systems should allow for mixing and measurement of both nitric oxide (NO) and carbon monoxide (CO) gases directly from an inspiratory reservoir just before use, with expired concentrations measured from an alveolar “collection” or continuously sampledviarapid gas analysers; 2) breath-hold time should be 10 s with chemiluminescence NO analysers, or 4–6 s to accommodate the smaller detection range of the NO electrochemical cell; 3) inspired NO and oxygen concentrations should be 40–60 ppm and close to 21%, respectively; 4) the alveolar oxygen tension (PAO2) should be measured by sampling the expired gas; 5) a finite specific conductance in the blood for NO (θNO) should be assumed as 4.5 mL·min-1·mmHg-1·mL-1of blood; 6) the equation for 1/θCO should be (0.0062·PAO2+1.16)·(ideal haemoglobin/measured haemoglobin) based on breath-holdingPAO2and adjusted to an average haemoglobin concentration (male 14.6 g·dL−1, female 13.4 g·dL−1); 7) a membrane diffusing capacity ratio (DMNO/DMCO) should be 1.97, based on tissue diffusivity.

Skin Cooling on Breath-Hold Duration and Predicted Emergency Air Supply Duration During Immersion

2020 ◽  
Vol 91 (7) ◽  
pp. 578-585
Author(s):  
Victory C. Madu ◽  
Heather Carnahan ◽  
Robert Brown ◽  
Kerri-Ann Ennis ◽  
Kaitlyn S. Tymko ◽  
...  
Keyword(s):  
Minute Ventilation ◽  
Hold Time ◽  
Whole Body ◽  
Breath Hold ◽  
Endurance Time ◽  
Skin Exposure ◽  
Breathing Apparatus ◽  
Air Supply ◽  
Skin Cooling ◽  
Breath Hold Duration

PURPOSE: This study was intended to determine the effect of skin cooling on breath-hold duration and predicted emergency air supply duration during immersion.METHODS: While wearing a helicopter transport suit with a dive mask, 12 subjects (29 ± 10 yr, 78 ± 14 kg, 177 ± 7 cm, 2 women) were studied in 8 and 20°C water. Subjects performed a maximum breath-hold, then breathed for 90 s (through a mouthpiece connected to room air) in five skin-exposure conditions. The first trial was out of water for Control (suit zipped, hood on, mask off). Four submersion conditions included exposure of the: Partial Face (hood and mask on); Face (hood on, mask off); Head (hood and mask off); and Whole Body (suit unzipped, hood and mask off).RESULTS: Decreasing temperature and increasing skin exposure reduced breath-hold time (to as low as 10 ± 4 s), generally increased minute ventilation (up to 40 ± 15 L · min−1), and decreased predicted endurance time (PET) of a 55-L helicopter underwater emergency breathing apparatus. In 8°C water, PET decreased from 2 min 39 s (Partial Face) to 1 min 11 s (Whole Body).CONCLUSION: The most significant factor increasing breath-hold and predicted survival time was zipping up the suit. Face masks and suit hoods increased thermal comfort. Therefore, wearing the suits zipped with hoods on and, if possible, donning the dive mask prior to crashing, may increase survivability. The results have important applications for the education and preparation of helicopter occupants. Thermal protective suits and dive masks should be provided.Madu VC, Carnahan H, Brown R, Ennis K-A, Tymko KS, Hurrie DMG, McDonald GK, Cornish SM, Giesbrecht GG. Skin cooling on breath-hold duration and predicted emergency air supply duration during immersion. Aerosp Med Hum Perform. 2020; 91(7):578–585.

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.

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