Depth limits of breath hold diving(an example of fennology)

Craig, Albert B.

doi:10.1016/0034-5687(68)90073-x

Cited by 48 publications

(36 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…He was able to reach a personal depth record of 50 m. Thus the use of GI permits breath-hold divers to reach, and in some situations to exceed, the depth limits set by their individual TLC/RV ratio. Indeed, the more recent depth records have well surpassed previous predictions based on theory not taking GI into account [9,10].…”

Section: Lung Hyperinflation: Foe or Friend?mentioning

confidence: 94%

Lung hyperinflation: foe or friend?

Eichinger

Walterspacher²,

Scholz³

et al. 2008

European Respiratory Journal

View full text Add to dashboard Cite

Breath-hold divers employ glossopharyngeal insufflation (GI) in order to prevent the lungs from compressing at great depth and to increase intrapulmonary oxygen stores, thus increasing breath-hold time.The presented case study shows the physiological data and dynamic magnetic resonance imaging (dMRI) findings of acute hyperinflation, deliberately induced by GI, in a breath-hold diver and discusses the current state of knowledge regarding the associated hazards of this unique competitive sport.Static and dynamic lung volumes and expiratory flows were within the normal range, with vital capacity and peak expiratory flow being higher than the predicted values. Airway resistance and diffusing capacity of the lung for carbon monoxide were normal. Static compliance was normal and increased five-fold with hyperinflation. dMRI revealed a preserved shape of the thorax and diaphragm with hyperinflation. A herniation of the lung beneath the sternum and enlargement of the costodiaphragmatic angle were additional findings during the GI manoeuvre. After expiration, complete resolution to baseline was demonstrated.Hyperinflation can be physiological and even protective under abnormal physical conditions in the sense of acute adaptation to deep breath-hold diving. Dynamic magnetic resonance imaging is adequate for visualisation of the sequence of the glossopharyngeal insufflation manoeuvre and the complete reversibility of deliberate hyperinflation.

show abstract

Section: Lung Hyperinflation: Foe or Friend?mentioning

confidence: 94%

Lung hyperinflation: foe or friend?

Eichinger

Walterspacher²,

Scholz³

et al. 2008

European Respiratory Journal

View full text Add to dashboard Cite

show abstract

“…An arterial rete has limited ability to expand, and its tortuosity and interconnections may trap bubbles or emboli and guarantee alternative flow pathways (collateral circulation) to prevent neural emboli and possible trauma (Vogl and Fisher, 1982;Blix et al, 2013). By contrast, the venous rete, being far more distensible, can engorge with blood and reduce the volume of gas-filled spaces, thereby protecting against lung squeeze [similar to the thoracic blood pooling reported in human breath-hold divers (Harrison and Tomlinson, 1956;Murdaugh et al, 1962;Craig, 1968;Hui, 1975;Ridgway et al, 1984)]. It has also been suggested that venous retes may help regulate pressure, flow or pulse, and affect blood composition (Hui, 1975).…”

Section: Chest Compliancementioning

confidence: 98%

“…lung squeeze) (Lundgren and Miller, 1999). In humans, these negative pressures cause blood to be drawn into the thoracic cavity (thoracic blood pooling) -this reduces the gas space volume and helps to reduce the pressure difference (Craig, 1968;Schaefer et al, 1968;Leith, 1989). In human breath-hold divers, pulmonary edema and hemorrhage are common; in the case of extreme negative intrathoracic pressures, cardiac arrhythmias and rupture of the vena cava have been reported (Scholander et al, 1962;Leith, 1989;Hansel et al, 2008;Lindholm et al, 2008;Linér and Andersson, 2008;Lindholm and Lundgren, 2009).…”

Section: Chest Compliancementioning

confidence: 99%

Respiratory function and mechanics in pinnipeds and cetaceans

Fahlman

Moore

García-Párraga

2017

Journal of Experimental Biology

View full text Add to dashboard Cite

In this Review, we focus on the functional properties of the respiratory system of pinnipeds and cetaceans, and briefly summarize the underlying anatomy; in doing so, we provide an overview of what is currently known about their respiratory physiology and mechanics. While exposure to high pressure is a common challenge among breath-hold divers, there is a large variation in respiratory anatomy, function and capacity between species -how are these traits adapted to allow the animals to withstand the physiological challenges faced during dives? The ultra-deep diving feats of some marine mammals defy our current understanding of respiratory physiology and lung mechanics. These animals cope daily with lung compression, alveolar collapse, transient hyperoxia and extreme hypoxia. By improving our understanding of respiratory physiology under these conditions, we will be better able to define the physiological constraints imposed on these animals, and how these limitations may affect the survival of marine mammals in a changing environment. Many of the respiratory traits to survive exposure to an extreme environment may inspire novel treatments for a variety of respiratory problems in humans.

show abstract

“…As the lungs are heterogeneous, alveolar collapse is also possible at volumes above RV. Still, it was concluded that the ratio between TLC and RV would determine the BH diver’s maximum dive depth [16]. Using typical values (TLC = 6.0 L; RV = 1.2 L), a total pressure of 5 bar (= 40 m) would be tolerable.…”

Section: Pulmonary Volumes Versus Ambient Pressurementioning

confidence: 99%

Effects of Breath-Hold Deep Diving on the Pulmonary System

Schipke¹,

Lemaître²,

Cleveland³

et al. 2019

Respiration

View full text Add to dashboard Cite

This short review focuses on pulmonary injury in breath-hold (BH) divers. When practicing their extreme leisure sport, they are exposed to increased pressure on pulmonary gas volumes, hypoxia, and increased partial gas pressures. Increasing ambient pressures do present a serious problem to BH deep divers, because the semi-rigid thorax prevents the deformation required by the Boyle-Mariotte law. As a result, a negative-pressure barotrauma (lung squeeze) with acute hemoptysis is not uncommon. Respiratory maneuvers such as glossopharyngeal insufflation (GI) and glossopharyngeal exsufflation (GE) are practiced to prevent lung squeeze and to permit equalizing the paranasal sinuses and the middle ear. GI not only impairs venous return, thereby provoking hypotension and even fainting, but also produces intrathoracic pressures likely to induce pulmonary barotrauma that is speculated to induce long-term injury. GE, in turn, further increases the already negative intrapulmonary pressure, thereby favoring alveolar collapse (atelectasis). Finally, hypoxia seemingly not only induces brain injury but initiates the opening of intrapulmonary shunts. These pathways are large enough to permit transpulmonary passage of venous N₂ bubbles, making stroke-like phenomena in deep BH divers possible.

show abstract

Depth limits of breath hold diving(an example of fennology)

Cited by 48 publications

References 19 publications

Lung hyperinflation: foe or friend?

Lung hyperinflation: foe or friend?

Respiratory function and mechanics in pinnipeds and cetaceans

Effects of Breath-Hold Deep Diving on the Pulmonary System

Contact Info

Product

Resources

About