Venous and Arterial Bubbles at Rest after No-Decompression Air Dives

Ljubković, Marko; Dujić, Željko; Møllerløkken, Andreas; Baković, Darija; Obad, Ante; Brešković, Toni; Brubakk, Alf O.

doi:10.1249/mss.0b013e31820618d3

Cited by 49 publications

(49 citation statements)

References 19 publications

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“…Also, as in our recent studies, we found crossing of gas bubbles to systemic arterial side. These arterializations occurred more often after air dives as compared to nitrox (seven vs. two arterializations, respectively), which could be explained by the higher overall bubble load after air diving (Ljubkovic et al , 2011. However, despite higher gas bubbling after air dives, nitrox diving had greater impact on endothelial function, as evidenced by signiWcantly reduced FMD response after nitrox diving.…”

Section: Figmentioning

confidence: 93%

Effects of successive air and nitrox dives on human vascular function

et al. 2011

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SCUBA diving is regularly associated with asymptomatic changes in cardiac, pulmonary and vascular function. The aim of this study was to evaluate the changes in vascular/endothelial function following SCUBA diving and to assess the potential difference between two breathing gases: air and nitrox 36 (36% oxygen and 64% nitrogen). Ten divers performed two 3-day diving series (no-decompression dive to 18 m with 47 min bottom time with air and nitrox, respectively), with 2 weeks pause in between. Arterial/endothelial function was assessed using SphygmoCor and flow-mediated dilation measurements, and concentration of nitrite before and after diving was determined in venous blood. Production of nitrogen bubbles post-dive was assessed by ultrasonic determination of venous gas bubble grade. Significantly higher bubbling was found after all air dives as compared to nitrox dives. Pulse wave velocity increased slightly (~6%), significantly after both air and nitrox diving, indicating an increase in arterial stiffness. However, augmentation index became significantly more negative after diving indicating smaller wave reflection. There was a trend for post-dive reduction of FMD after air dives; however, only nitrox diving significantly reduced FMD. No significant differences in blood nitrite before and after the dives were found. We found that nitrox diving affects systemic/vascular function more profoundly than air diving by reducing FMD response, most likely due to higher oxygen load. Both air and nitrox dives increased arterial stiffness, but decreased wave reflection suggesting a decrease in peripheral resistance due to exercise during diving. These effects of nitrox and air diving were not followed by changes in plasma nitrite.

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Section: Figmentioning

confidence: 93%

Effects of successive air and nitrox dives on human vascular function

et al. 2011

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“…These studies were conducted at rest and after arm or leg exercise to elicit bubble release from vascular margins, exactly as described in our previous report (25). Bubble grading employed a modified Brubakk scale that has been used in several studies (12). The grading system is as follows: 0, no bubbles; 1, occasional bubbles; 2, at least one bubble every four cardiac cycles; 3, at least one bubble every cardiac cycle; 4, continuous bubbling with modifiers [(a ϭ at least one bubble per cm 2 in all frames), (b ϭ at least three bubbles per cm 2 in all frames), or (c ϭ almost complete "whiteout" but individual bubbles can still be discerned)] and 5, whiteout where individual bubbles cannot be discerned.…”

Section: Subjectsmentioning

confidence: 99%

“…The central place of bubbles as an inciting factor for DCS is widely accepted, yet most decompression procedures generate asymptomatic blood-borne bubbles (4,12,13). Inert gases inhaled while breathing are taken up by tissues in proportion to the ambient pressure, and when pressure is reduced, some of the gas released from tissues forms bubbles due to the presence of gas cavitation nuclei (6,33,34).…”

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confidence: 99%

Ascorbic acid supplementation diminishes microparticle elevations and neutrophil activation following SCUBA diving

Yang

Barak

Dujić

et al. 2015

American Journal of Physiology-Regulatory, Integrative and Comp

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-Predicated on evidence that diving-related microparticle generation is an oxidative stress response, this study investigated the role that oxygen plays in augmenting production of annexin V-positive microparticles associated with open-water SCUBA diving and whether elevations can be abrogated by ascorbic acid. Following a cross-over study design, 14 male subjects ingested placebo and 2-3 wk later ascorbic acid (2 g) daily for 6 days prior to performing either a 47-min dive to 18 m of sea water while breathing air (ϳ222 kPa N2/59 kPa O2) or breathing a mixture of 60% O2/balance N2 from a tight-fitting face mask at atmospheric pressure for 47 min (ϳ40 kPa N2/59 kPa O2). Within 30 min after the 18-m dive in the placebo group, neutrophil activation, and platelet-neutrophil interactions occurred, and the total number of microparticles, as well as subgroups bearing CD66b, CD41, CD31, CD142 proteins or nitrotyrosine, increased approximately twofold. No significant elevations occurred among divers after ingesting ascorbic acid, nor were elevations identified in either group after breathing 60% O2. Ascorbic acid had no significant effect on post-dive intravascular bubble production quantified by transthoracic echocardiography. We conclude that high-pressure nitrogen plays a key role in neutrophil and microparticle-associated changes with diving and that responses can be abrogated by dietary ascorbic acid supplementation.

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“…DCS is the term used when clinical symptoms of this transition manifest in humans. While bubbles are thought to be the precursor for the development of DCS, particularly if within the arterial circulation (Ljubkovic et al, 2011), the presence of gas bubbles alone does not indicate that DCS has, or will, develop (Brubakk and Eftedal, 2001; Barak and Katz, 2005; Ljubkovic et al, 2011). Symptoms experienced in human DCS cases are very varied and non-specific, and are dependent on where gas bubbles lodge and the degree of tissue damage caused.…”

Section: Introductionmentioning

confidence: 99%

“…Secondary mechanisms include activation of the complement cascade or activation of inflammatory pathways (Kayar et al, 1997; Thom et al, 2011). These pathways are an area of great interest in human DCS studies and are triggered via endothelial damage and the release of microparticles (small vesicles or fragments that are released from stressed or damaged endothelium and circulate in the blood) in response to decompression stress (Barak and Katz, 2005; Brubakk et al, 2005; Ljubkovic et al, 2011; Thom et al, 2011). Multiple risk factors have been modeled to investigate what factors result in the development of DCS in humans subsequent to gas bubble formation, but the process remains poorly understood (Weathersby et al, 1984, 1992; Pilmanis et al, 2004; Barak and Katz, 2005).…”

Section: Introductionmentioning

confidence: 99%

The use of Diagnostic Imaging for Identifying Abnormal Gas Accumulations in Cetaceans and Pinnipeds

Dennison¹,

Fahlman²,

Moore³

2012

Front. Physio.

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Recent dogma suggested that marine mammals are not at risk of decompression sickness due to a number of evolutionary adaptations. Several proposed adaptations exist. Lung compression and alveolar collapse that terminate gas-exchange before a depth is reached where supersaturation is significant and bradycardia with peripheral vasoconstriction affecting the distribution, and dynamics of blood and tissue nitrogen levels. Published accounts of gas and fat emboli and dysbaric osteonecrosis in marine mammals and theoretical modeling have challenged this view-point, suggesting that decompression-like symptoms may occur under certain circumstances, contrary to common belief. Diagnostic imaging modalities are invaluable tools for the non-invasive examination of animals for evidence of gas and have been used to demonstrate the presence of incidental decompression-related renal gas accumulations in some stranded cetaceans. Diagnostic imaging has also contributed to the recognition of clinically significant gas accumulations in live and dead cetaceans and pinnipeds. Understanding the appropriate application and limitations of the available imaging modalities is important for accurate interpretation of results. The presence of gas may be asymptomatic and must be interpreted cautiously alongside all other available data including clinical examination, clinical laboratory testing, gas analysis, necropsy examination, and histology results.

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Venous and Arterial Bubbles at Rest after No-Decompression Air Dives

Cited by 49 publications

References 19 publications

Effects of successive air and nitrox dives on human vascular function

Effects of successive air and nitrox dives on human vascular function

Ascorbic acid supplementation diminishes microparticle elevations and neutrophil activation following SCUBA diving

The use of Diagnostic Imaging for Identifying Abnormal Gas Accumulations in Cetaceans and Pinnipeds

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