Gas bubble disease

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Gas bubble disease is a disease of fish that are exposed to water supersaturated with natural gases like oxygen, carbon dioxide, or nitrogen. [1] Bubbles of gas may form in the eyes, skin, gills, and fins. [2] It becomes prominent whenever there is a change in temperature and pressure in environments, aquatic turbulence, and a disturbance in biotic metabolisms. [3]

Contents

Signs and symptoms

Gas bubble disease can be detected by the formation of small gas bubbles under the epidermis which includes the formation of gas bubbles in the skin, the gills and eyeballs causing exophtalmia. Gas bubbles may also form in extremities (fins), in the vascular system where they often cause embolism and in their mouth opening. The gas bubble disease may cause floating problems due to the excessive amount of gas in their bodies, ultimately leading to upside-down swimming and death. [3]

Gas bubble disease may also occur in humans and is commonly known as decompression sickness. It generally occurs in divers when they resurface without using proper decompression procedures. The supersaturation of nitrogen in the body tissues is causing an unbalanced gas saturation in blood vessels and organs. [3] The main concern with this disease in particular is when it develops and transforms into air embolism, which causes severe blockades in the lung and in the blood vessels, which is especially dangerous in arteries. Expanding gases can rupture the small air-cavities located in the lungs (alveoli), thus causing pulmonary barotrauma which can ultimately lead to death due to pulmonary failure. [4]

Origin and causes

The gas bubble disease is a result of an over-saturation of nitrogen or other gases in the body tissues caused by a supersaturation of gases in the water. This supersaturation is mainly caused by the changes of abiotic environmental factors including pressure, temperature and salinity since these factors influence the amount of gases dissolving in water. [5]

Pressure

The decrease in the pressure of the environment will causes the supersaturation of the water. [5]

Temperature

An increase in temperature of the environment will cause a supersaturation of the water. [5]

Salinity

An increase in salinity of water may cause gas supersaturation. [5] Therefore, a difference in the salinity levels of lakes or rivers is one of the causes of the gas bubble disease. [6]

Other natural causes

Other natural causes of gas bubble disease the gas saturation caused by an increase of the concentration of nitrogen in natural water resources due to the increasing nitrogen concentration in underground rivers and lakes or the supersaturation of water caused by cascades or waterfalls. [3] When the water falls into the pool it is forcing the nitrogen into the water of the pool. [3]

Diagnosis

"The resulting abnormal physical presence of gases can block blood vessels (hemostasis) or tear tissues, and may result in death" (Bouck 2011). [6]

Gas bubble disease may develop in three different stages:

Prevention

The gas bubble disease can generally be prevented by avoiding the factor that cause the disease.

Small gas bubbles in fish can be prevented and somewhat cured by relocating fish into deep water that contains higher pressures and therefore a higher amount of gases can be dissolved in the water. This will cause nitrogen excess to be dissolved into the body tissues and the gas bubbles will eventually disappear. [3]

Aeration is an effective method to stabilise nitrogen and oxygen in water, since it is able to absorb equal quantities of oxygen and nitrogen and forces them into the water to maintain a balance for "rearing fish" (Rucker, 1972). [3]  

Related Research Articles

<span class="mw-page-title-main">Decompression sickness</span> Disorder caused by dissolved gases forming bubbles in tissues

Decompression sickness is a medical condition caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompression. DCS most commonly occurs during or soon after a decompression ascent from underwater diving, but can also result from other causes of depressurisation, such as emerging from a caisson, decompression from saturation, flying in an unpressurised aircraft at high altitude, and extravehicular activity from spacecraft. DCS and arterial gas embolism are collectively referred to as decompression illness.

<span class="mw-page-title-main">Air embolism</span> Vascular blockage by air bubbles

An air embolism, also known as a gas embolism, is a blood vessel blockage caused by one or more bubbles of air or other gas in the circulatory system. Air can be introduced into the circulation during surgical procedures, lung over-expansion injury, decompression, and a few other causes. In flora, air embolisms may also occur in the xylem of vascular plants, especially when suffering from water stress.

Diving physics, or the physics of underwater diving is the basic aspects of physics which describe the effects of the underwater environment on the underwater diver and their equipment, and the effects of blending, compressing, and storing breathing gas mixtures, and supplying them for use at ambient pressure. These effects are mostly consequences of immersion in water, the hydrostatic pressure of depth and the effects of pressure and temperature on breathing gases. An understanding of the physics behind is useful when considering the physiological effects of diving, breathing gas planning and management, diver buoyancy control and trim, and the hazards and risks of diving.

Decompression Illness (DCI) comprises two different conditions caused by rapid decompression of the body. These conditions present similar symptoms and require the same initial first aid. Scuba divers are trained to ascend slowly from depth to avoid DCI. Although the incidence is relatively rare, the consequences can be serious and potentially fatal, especially if untreated.

Dysbarism refers to medical conditions resulting from changes in ambient pressure. Various activities are associated with pressure changes. Underwater diving is the most frequently cited example, but pressure changes also affect people who work in other pressurized environments, and people who move between different altitudes.

Diving disorders, or diving related medical conditions, are conditions associated with underwater diving, and include both conditions unique to underwater diving, and those that also occur during other activities. This second group further divides into conditions caused by exposure to ambient pressures significantly different from surface atmospheric pressure, and a range of conditions caused by general environment and equipment associated with diving activities.

In physiology, isobaric counterdiffusion (ICD) is the diffusion of different gases into and out of tissues while under a constant ambient pressure, after a change of gas composition, and the physiological effects of this phenomenon. The term inert gas counterdiffusion is sometimes used as a synonym, but can also be applied to situations where the ambient pressure changes. It has relevance in mixed gas diving and anesthesiology.

<span class="mw-page-title-main">Decompression (diving)</span> Pressure reduction and its effects during ascent from depth

The decompression of a diver is the reduction in ambient pressure experienced during ascent from depth. It is also the process of elimination of dissolved inert gases from the diver's body which accumulate during ascent, largely during pauses in the ascent known as decompression stops, and after surfacing, until the gas concentrations reach equilibrium. Divers breathing gas at ambient pressure need to ascend at a rate determined by their exposure to pressure and the breathing gas in use. A diver who only breathes gas at atmospheric pressure when free-diving or snorkelling will not usually need to decompress. Divers using an atmospheric diving suit do not need to decompress as they are never exposed to high ambient pressure.

Hypobaric decompression is the reduction in ambient pressure below the normal range of sea level atmospheric pressure. Altitude decompression is hypobaric decompression which is the natural consequence of unprotected elevation to altitude, while other forms of hypobaric decompression are due to intentional or unintentional release of pressurization of a pressure suit or pressurized compartment, vehicle or habitat, and may be controlled or uncontrolled, or the reduction of pressure in a hypobaric chamber.

<span class="mw-page-title-main">Decompression practice</span> Techniques and procedures for safe decompression of divers

To prevent or minimize decompression sickness, divers must properly plan and monitor decompression. Divers follow a decompression model to safely allow the release of excess inert gases dissolved in their body tissues, which accommodated as a result of breathing at ambient pressures greater than surface atmospheric pressure. Decompression models take into account variables such as depth and time of dive, breathing gasses, altitude, and equipment to develop appropriate procedures for safe ascent.

<span class="mw-page-title-main">History of decompression research and development</span> Chronological list of notable events in the history of diving decompression.

Decompression in the context of diving derives from the reduction in ambient pressure experienced by the diver during the ascent at the end of a dive or hyperbaric exposure and refers to both the reduction in pressure and the process of allowing dissolved inert gases to be eliminated from the tissues during this reduction in pressure.

<span class="mw-page-title-main">Decompression theory</span> Theoretical modelling of decompression physiology

Decompression theory is the study and modelling of the transfer of the inert gas component of breathing gases from the gas in the lungs to the tissues and back during exposure to variations in ambient pressure. In the case of underwater diving and compressed air work, this mostly involves ambient pressures greater than the local surface pressure, but astronauts, high altitude mountaineers, and travellers in aircraft which are not pressurised to sea level pressure, are generally exposed to ambient pressures less than standard sea level atmospheric pressure. In all cases, the symptoms caused by decompression occur during or within a relatively short period of hours, or occasionally days, after a significant pressure reduction.

<span class="mw-page-title-main">Haldane's decompression model</span> Decompression model developed by John Scott Haldane

Haldane's decompression model is a mathematical model for decompression to sea level atmospheric pressure of divers breathing compressed air at ambient pressure that was proposed in 1908 by the Scottish physiologist, John Scott Haldane, who was also famous for intrepid self-experimentation.

<span class="mw-page-title-main">Thermodynamic model of decompression</span> Early model in which decompression is controlled by volume of gas bubbles forming in tissues

The thermodynamic model was one of the first decompression models in which decompression is controlled by the volume of gas bubbles coming out of solution. In this model, pain only DCS is modelled by a single tissue which is diffusion-limited for gas uptake and bubble-formation during decompression causes "phase equilibration" of partial pressures between dissolved and free gases. The driving mechanism for gas elimination in this tissue is inherent unsaturation, also called partial pressure vacancy or the oxygen window, where oxygen metabolised is replaced by more soluble carbon dioxide. This model was used to explain the effectiveness of the Torres Straits Island pearl divers empirically developed decompression schedules, which used deeper decompression stops and less overall decompression time than the current naval decompression schedules. This trend to deeper decompression stops has become a feature of more recent decompression models.

<span class="mw-page-title-main">Physiology of decompression</span> The physiological basis for decompression theory and practice

The physiology of decompression is the aspect of physiology which is affected by exposure to large changes in ambient pressure. It involves a complex interaction of gas solubility, partial pressures and concentration gradients, diffusion, bulk transport and bubble mechanics in living tissues. Gas is breathed at ambient pressure, and some of this gas dissolves into the blood and other fluids. Inert gas continues to be taken up until the gas dissolved in the tissues is in a state of equilibrium with the gas in the lungs, or the ambient pressure is reduced until the inert gases dissolved in the tissues are at a higher concentration than the equilibrium state, and start diffusing out again.

Diving hazards are the agents or situations that pose a threat to the underwater diver or their equipment. Divers operate in an environment for which the human body is not well suited. They face special physical and health risks when they go underwater or use high pressure breathing gas. The consequences of diving incidents range from merely annoying to rapidly fatal, and the result often depends on the equipment, skill, response and fitness of the diver and diving team. The classes of hazards include the aquatic environment, the use of breathing equipment in an underwater environment, exposure to a pressurised environment and pressure changes, particularly pressure changes during descent and ascent, and breathing gases at high ambient pressure. Diving equipment other than breathing apparatus is usually reliable, but has been known to fail, and loss of buoyancy control or thermal protection can be a major burden which may lead to more serious problems. There are also hazards of the specific diving environment, and hazards related to access to and egress from the water, which vary from place to place, and may also vary with time. Hazards inherent in the diver include pre-existing physiological and psychological conditions and the personal behaviour and competence of the individual. For those pursuing other activities while diving, there are additional hazards of task loading, of the dive task and of special equipment associated with the task.

<span class="mw-page-title-main">Built-in breathing system</span> System for supply of breathing gas on demand within a confined space

A built-in breathing system is a source of breathing gas installed in a confined space where an alternative to the ambient gas may be required for medical treatment, emergency use, or to minimise a hazard. They are found in diving chambers, hyperbaric treatment chambers, and submarines.

Inner ear decompression sickness, (IEDCS) or audiovestibular decompression sickness is a medical condition of the inner ear caused by the formation of gas bubbles in the tissues or blood vessels of the inner ear. Generally referred to as a form of decompression sickness, it can also occur at constant pressure due to inert gas counterdiffusion effects.

References

  1. Bohl, M (May 1997). "Gas bubble disease of fish". Tierarztliche Praxis. 25 (3): 284–288. PMID   9289892.
  2. Gültepe, N; Ateş, O; Hisar, O (Sep 2011). "Carbonic anhydrase activities from the rainbow trout lens correspond to the development of acute gas bubble disease". Journal of Aquatic Animal Health. 23 (3): 134–139. Bibcode:2011JAqAH..23..134G. doi:10.1080/08997659.2011.616848. PMID   22216712.
  3. 1 2 3 4 5 6 7 Rucker, Robert R. (1972). Gas-bubble Disease of Salmonids: A Critical Review. Bureau of Sport Fisheries and Wildlife.
  4. Hulst, Robert A. van; Klein, Jan; Lachmann, Burkhard (2003). "Gas embolism: pathophysiology and treatment". Clinical Physiology and Functional Imaging. 23 (5): 237–246. doi:10.1046/j.1475-097X.2003.00505.x. ISSN   1475-097X. PMID   12950319. S2CID   24087721.
  5. 1 2 3 4 "Fish Diseases". aun.edu.eg. Retrieved 2019-12-08.
  6. 1 2 3 4 5 Bouck, Gerald R. (1980-11-01). "Etiology of Gas Bubble Disease". Transactions of the American Fisheries Society. 109 (6): 703–707. Bibcode:1980TrAFS.109..703B. doi:10.1577/1548-8659(1980)109<703:eogbd>2.0.co;2. ISSN   0002-8487.