Pressure hyperbaric chamber

Increased pressure [hyperbaric chamber, respiratory ventilators (eg, PEEP or CPPB)] P02 polarographic electrode "error" due to halogenated hydrocarbons (eg, llalothane) t P02 usually <50... 

Solubility affected by pressnre. (a) SCUBA divers must pay attention to the solubility of gases in die blood and die fact diat solubility increases with pressure, (b) A hyperbaric chamber. People who have problems breathing can be placed in a hyperbaric chamber where they are exposed to a higher partial pressure of oxygen. 

Thom and coworkers published results on the stimulation of perivascular NO synthesis by oxygen [127], To perform this study a 200 pm diameter electrode (ISONOP200) was placed between the aorta and vena cava of anesthetized rats and mice (rodents) and then the rodents were placed inside a hyperbaric chamber. Inside the hyperbaric chamber the partial pressure of 02 was regulated/changed as NO concentration was monitored. Figure 1.11 shows that NO concentration increased as a function of 02 partial pressure. This experiment is important for understanding how NO synthesis, by NOS, is altered and regulated by 02. 

Divers who ascend too quickly can develop the bends, a condition caused by the formation of nitrogen bubbles in the blood. Treatment involves placement in this high-pressure tank called a hyperbaric chamber, and a slow, controlled change to atmospheric pressure. 

CO is bound to hemoglobin and does not allow it to carry oxygen. Oxygen under high pressure in the hyperbaric chamber is dissolved in the plasma and is carried to the tissues without the aid of hemoglobin. 

The binding of CO to hemoglobin is fully dissociable, and dissociation requires ventilation. After removal from exposure to CO, administration of O reverses CO binding to hemoglobin. Utilization of 100 percent accelerates the washout of CO. Use of hyperbaric chambers with pressures up to 2 atmospheres speeds up the CO washout process even more. Addition of 5 to 7 percent CO to the O is sometimes used as a prompt to ventilatory exchange. One disadvantage of the addition of CO is the serious acidosis that results when the respiratory acidosis produced by CO inhalation is added to the metabolic acidosis produced by O deprivation in the tissues because of CO poisoning. 

Carbon monoxide poisoning is treated by administration of pure O2 which promotes the shift of the above equilibrium to the left. This can be made even more effective by placing the victim in a hyperbaric chamber in which the pressure of O2 can be made greater than 1 atm. 

Figure 1 During HBOT, the patient iies in a hyperbaric chamber. A technician controls the pressure and oxygen levels.

If a diver does surface too quickly, some hospitals have hyperbaric chambers, where the sea depth pressures are reapplied and slowly reduced while the victim breathes oxygen as pure as 100 percent. 

Victims of carbon monoxide poisoning are placed in a hyperbaric chamber where the pressure is raised above 1 atm and a richer oxygen environment exists. If the pressure is raised from 1 atm to 3 atm, what will be the proportional change in oxygen solubility in blood Use Henry s law and assume blood behaves like water. 

Hyperbaric chambers in medical facilities for performing certain procedures operate under elevated atmospheric pressure. They are another example of high pressure environments. Some hyperbaric chambers have solid enclosures and some are simply plastic bubbles. The thicker the walls of the enclosure, the greater the pressure it can contain. Medical hyperbaric chambers have uses in elevated oxygen therapy for bmns, gangrene, air embolisms, and other diseases and conditions. 

Eichers P. Hyperbaric chamber and pressure vessel tests. Medtronic Design Assurance Rep 1992 PE92-292. 

Hyperbaric chambers must be strongly built to resist significant internal gas pressure. 

The Catalina Hyperbaric Chamber at the University of Southern California s Wrigley Marine Science Center treats mostly victims of diving accidents. In one treatment protocol, the chamber is pressurized to 6.0 atm with compressed air and the patient breathes a mixture of gases that is 47 percent O2 by volume. In another protocol, the chamber is pressurized with compressed air to 2.8 atm and the patient breathes pure O2. Determine the partial pressure of O2 in each treatment protocol and compare the results. 

Strategy Because the gas the patient breathes is inside the hyperbaric chamber, its total pressure is the same as the chamber pressure. To obtain the partial pressure of O2, multiply the mole ftaction of O2 in the breathing gas in each protocol by the total pressure (Equation 11.13). 

A patient undergoing treatment in a hyperbaric chamber must also undergo decompression (reduction of pressure) at a rate that slowly reduces the concentration of dissolved oxygen in the blood. If decompression is too rapid, the oxygen dissolved in the blood may form gas bubbles in the circulatory system. 

Student Annotation "Monoplace" hyperbaric chambers, which are large enough to accommodate only one person, typically are pressurized with pure oxygen, although monoplace chambers are not used to treat decompression injuries. 

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