Alveolar gas exchange during breath holding with air

Lanphier, EH; Rahn, Hermann

doi:10.1152/jappl.1963.18.3.478

Cited by 34 publications

(26 citation statements)

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“…A similar reversal of CO 2 flux has been observed during apnoea in resting humans and animals (Lanphier and Rahn 1963;Hesser et al 1968;Hong et al 1971;Ferretti et al 1991) and in breath-hold divers (Ferretti 2001).…”

Section: Reduced Pulmonary _ V V O 2 During Apnoeasupporting

confidence: 74%

Pulmonary gas exchange during apnoea in exercising men

Lindholm

Linnarsson

2002

Eur J Appl Physiol

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There is indirect evidence that cardiovascular responses to apnoea result in a temporary slowing of the O(2) uptake in the lungs in exercising humans. The present study was undertaken in an attempt to determine directly to what extent this occurs, and whether the magnitude of this slowing is such that it must be the result of concomitant cardiovascular readjustments and not merely a result of an isolated apnoea-induced fall in the arterial O(2) saturation ( S(a)O(2)). Eight men performed 120 W leg exercise and performed repeated apnoeas of 10-40 s duration. Heart rate, S(a)O(2), and breath-by-breath gas exchange were determined. Pulmonary O(2) uptake fell gradually as breath-holds proceeded by [mean (SEM)] 74 (3)% of the pre-apnoea O(2) uptake. This decrease was significantly larger than could be accounted for by the fall in S(a)O(2) alone [ S(a)O(2) fall -30 (3)%], which it is estimated would have resulted in a fall of pulmonary O(2) uptake of -54 (5)%. We conclude that cardiovascular responses to apnoea contribute significantly to reducing pulmonary O(2) uptake during apnoea in exercising men.

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Section: Reduced Pulmonary _ V V O 2 During Apnoeasupporting

confidence: 74%

Pulmonary gas exchange during apnoea in exercising men

Lindholm

Linnarsson

2002

Eur J Appl Physiol

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“…3). This is at variance with what is commonly observed in non-divers, who show identical DVLO 2 and _ V O 2r values during dry breath-holding (Lanphier and Rahn 1963b;Craig and Harley 1968;Hong et al 1971). Conversely, DVLCO 2 is almost equal to zero, and is sometimes even negative (reversal of carbon dioxide¯ow), in both divers and non-divers.…”

Section: Studycontrasting

confidence: 48%

Extreme human breath-hold diving

Ferretti¹

2001

Eur J Appl Physiol

148

155

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In this paper, the respiratory, circulatory and metabolic adjustments to human extreme breath-hold diving are reviewed. A survey of the literature reveals that in extreme divers, adaptive mechanisms take place that allow prolongation of apnoea beyond the limits attained by non-diving subjects, and preservation of oxygen stores during the dives. The occurrence of a diving response, including peripheral vasoconstriction, increased arterial blood pressure, bradycardia and lowered cardiac output, is strongly implicated. Some peripheral regions may be excluded from perfusion, with consequent reliance on anaerobic metabolism. In addition, extreme breath-hold divers show a blunted ventilatory response to carbon dioxide breathing, possibly as a consequence of frequent exposure to high carbon dioxide partial pressures during the dives. These mechanisms allow the attainment of particularly low alveolar oxygen (< 30 mmHg) and high alveolar carbon dioxide (> 50 mmHg) partial pressures at the end of maximal dry breath-holds, and reduce oxygen consumption during the dive at the expense of increased anaerobic glycolysis (rate of blood lactate accumulation > 0.04 mM.s-1). The current absolute world record for depth in breath-hold diving is 150 m. Its further improvement depends upon how far the equilibrium between starting oxygen stores, the overall rate of energy expenditure, the fraction of energy provided by anaerobic metabolism and the diving speed can be pushed, with consciousness upon emersion. The ultimate limit to breath-hold diving records may indeed be imposed by an energetic constraint.

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“…Note that: (a) t BH was shorter at higher WRs, declining in this example from 43 s at 30 W to 16 s at 150 W; and (b) for the ®rst post-breath-hold expiration, P ET CO 2 was higher and P ET O 2 lower than the values obtained immediately prior to the breath-hold, consistent with retention of metabolically-produced carbon dioxide and continual extraction of oxygen from the trapped lung gas during the breath-hold (e.g. Otis et al 1948;Lanphier and Rahn 1963;Mithoefer 1965b;Ferrigno and Lundgren 1999).…”

Section: Resultsmentioning

confidence: 53%

“…assumed to be 100%, with thè`1 00'' being unchanged at the various end-points), but also the rate of change of the stimuli (including both humoral and respiratory-mechanical) during the breathhold (e.g. A Ê strand 1960; Lanphier and Rahn 1963;Mithoefer 1965b). It is this latter component that is likely to be variable at dierent WRs, and highly variable among subjects at any particular WR.…”

Section: Discussionmentioning

confidence: 99%

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Is breath-hold time an objective index of exertional dyspnoea in humans?

Ward

Macias

Whipp

2001

European Journal of Applied Physiology

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Since dyspnoeic sensation (d) increases progressively with work rate (WR) and the duration of a volitional breath-hold (t BH ) shortens, we wished to explore whether t BH might correlate suciently closely with d to provide a quantitative and descriptor-free index of respiratory sensation during dynamic exercise. Nine healthy males exercised on a cycle ergometer at a series of constant WRs, above and below the lactate threshold. Ventilatory and gas exchange variables were measured breath-by-breath. At each WR, breath-holds to the limit of tolerance were taken; d was recorded (visual-analog scale) immediately prior to and throughout each breath-hold. During breath-holds, d increased with time as a``break-away'' monoexponential characteristic, reaching the maximum (100%) at the breakpoint. Despite end-tidal partial pressure of carbon dioxide at the break-point being higher and end-tidal partial pressure of oxygen being lower with increasing WR, the relationship between WR and t BH declined curvilinearly (i.e. with large falls in t BH occurring in the low WR range, but far smaller reductions at higher WRs). The t BH /minute ventilation relationship had a similar form. The relationship between pre-breath-hold d and t BH was also complex: the large reductions in t BH in the low WR range were associated with only modest increases in pre-BH d while, at higher WRs, the progressively smaller decrements in t BH were associated with progressively larger increases in d. We therefore conclude that breath-hold duration is unlikely to provide a useful correlate of exertional dyspnoea during dynamic exercise. Furthermore, the relative prolongation of t BH at high WRs (accounting for the moreextreme levels of end-tidal gas tensions) may re¯ect the attention-diverting in¯uence of the exercise per se.

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Alveolar gas exchange during breath holding with air

Cited by 34 publications

References 0 publications

Pulmonary gas exchange during apnoea in exercising men

Pulmonary gas exchange during apnoea in exercising men

Extreme human breath-hold diving

Is breath-hold time an objective index of exertional dyspnoea in humans?

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