Respiratory Insufficiency—Pathophysiology, Diagnosis, Oxygen Therapy

Assuming a lung Po2 of about 3000 mm Hg (4 atm pressure), what is the approximate total oxygen content in each 100 ml of blood, as represented by point A in Figure 45-2?

What is the primary danger associated with breathing oxygen at 4 atm pressure for a period of 30 to 60 minutes?

What is the primary mechanism that causes nervous system oxygen toxicity when tissue PO2 levels become extremely high?

Under what condition can a person develop chronic oxygen poisoning, leading to pulmonary disability such as lung passageway congestion and pulmonary edema?

According to the text, why does chronic oxygen poisoning primarily affect the lungs and not other body tissues when breathing 1 atm O2?

What is the maximum alveolar CO2 pressure (PCO2) a diver can typically tolerate before the situation becomes intolerable and the respiratory center begins to be depressed?

What is the primary gas responsible for causing decompression sickness when a diver ascends too quickly?

How many times more soluble is nitrogen in body fat than it is in body water?

Which tissue in the body takes the longest to become saturated with nitrogen during a deep dive?

What is the volume of nitrogen dissolved in the body of a diver saturated at a depth of 100 feet?

Pain in the joints and muscles, known as 'the bends', affects what percentage of individuals who experience decompression sickness?

What is the condition called 'the chokes' in the context of decompression sickness?

According to the example decompression schedule for a diver at 190 feet for 60 minutes, how much time is spent at the 10-feet depth stop?

Which of the following is NOT a reason for using helium instead of nitrogen in gas mixtures for very deep dives?

At a depth of 700 feet (22 atm pressure), what percentage of oxygen in the breathing mixture is sufficient to provide all the O2 required by a diver while avoiding toxicity?

What is the function of the 'demand' valve in an open-circuit SCUBA system?

What is the most significant limiting factor for the amount of time a SCUBA diver can remain at a depth like 200 feet?

What is a major physiological problem a person must prevent during an escape from a submerged submarine?

For which of the following conditions has hyperbaric oxygen therapy been shown to be particularly successful, often converting a previously fatal condition into one that is cured?

At what PO2 pressure do the clostridial organisms that cause gas gangrene stop growing?

What is the critical alveolar PO2 level above which the hemoglobin-O2 buffer mechanism fails, leading to a rapid rise in tissue PO2?

According to Figure 45-1, what is the atmospheric pressure experienced by a diver at a depth of 100 feet (30.5 meters)?

What happens to a gas volume of 1 liter at sea level when it is taken down to a depth of 233 feet, according to Figure 45-1?

Which factor greatly increases a diver's susceptibility to acute oxygen toxicity, causing symptoms to appear much earlier and with greater severity?

Why are nervous tissues especially susceptible to the lethal effects of acute oxygen toxicity?

If a diver remains underwater at a deep level for only a few minutes, what is the expected level of nitrogen dissolution in their tissues?

What is the collective term for the multiple problems, including 'the bends' and 'the chokes,' that arise from the removal of nitrogen from tissues during ascent?

Approximately what percentage of the total dissolved nitrogen in the body is liberated within the first hour of a diver being brought to the surface slowly?

What is the primary purpose of 'saturation diving'?

What is the primary component of the gas inside the bubbles that form during decompression sickness?

The open-circuit demand type of SCUBA is used in what percentage of all sports and commercial diving?

What action must a person take to prevent air embolism when escaping from a submerged submarine?

What is believed to be responsible for both the toxicity and the therapeutic benefits of hyperbaric oxygen therapy?

In hyperbaric oxygen therapy, at what typical PO2 values is the oxygen administered to the patient?

What is the primary difference between the effect of depth on CO2 partial pressure versus O2 partial pressure in a diver breathing compressed air?

When a diver experiences CO2 toxicity due to buildup in a rebreathing apparatus, what is the eventual effect on the respiratory center at very high PCO2 levels?

When treating a patient with decompression sickness who has already surfaced, what is the immediate and crucial first step in tank decompression?

What is the primary reason that fat tissue reaches equilibrium with dissolved nitrogen much slower than the water of the body?

Which of the following conditions is NOT listed as being valuable or possibly valuable for treatment with hyperbaric oxygen therapy?

What is the total pressure of gases inside the body fluids of a diver equilibrated at a depth where the outside pressure is 5000 mm Hg?

When a diver suddenly ascends from a depth with 5000 mm Hg external pressure to sea level (760 mm Hg), what happens to the gases dissolved in their body?

Which tissue's high susceptibility to damage from oxidizing free radicals is the primary cause of the acute lethal effects of oxygen toxicity?

What is the normal, safe range for tissue PO2 that the hemoglobin-O2 buffer mechanism is responsible for maintaining?

According to Figure 45-2, the oxygen-hemoglobin dissociation curve shows that beyond a certain PO2, the amount of oxygen combined with hemoglobin plateaus. What happens to the amount of dissolved oxygen as PO2 continues to increase to 3040 mm Hg?

What is the approximate volume of nitrogen dissolved in the entire body at sea level?

What causes the symptoms of decompression sickness, such as joint pain or 'the chokes'?

What is the third reason provided for using helium instead of nitrogen in gas mixtures for very deep dives?

What is the primary physiological principle that limits dive time on an open-circuit SCUBA system at increasing depth?

What is the theoretical escape depth from a submarine that could be achieved using a proper rebreathing device with helium?

What happens to the tissue PO2 once the alveolar PO2 rises above a critical level like 2 atm?