Question

Explain the physiological differences between hyperoxic acute lung injury (HALI) and oxygen therapy in the context of:

1. Airways disease
2. Diving
3. Exercise intervention in diabetes

Answer 1

Hyperoxic acute lung injury

Prolonged breathing of very high FIO2 (FIO2 ≥ 0.9) uniformly causes severe hyperoxic acute lung injury (HALI) and, without a reduction of FIO2, is usually fatal. The severity of HALI is directly proportional to PO2 (particularly above 450 mm Hg, or an FIO2 of 0.6) and exposure duration.

Oxygen therapy is essential in airway disease, diving accidents, and in exercise intervention in diabetes.Oxygen therapy, or O2 therapy, is a medical therapy wherein supplemental oxygen is given to anyone suffering from oxygen deficiency. The purpose of oxygen treatment is to help patients breathe better and improve their blood oxygen levels.

Need of oxygen is varies in different conditions, in case of airway disease, Oxygen)(O2) is gas used as a drug/medication and a such should be prescribed and administered in the right manner with regards to presenting indications for it's use; which is always in the case of hypoxaemia. It has side effects and specific risks, but, with objective monitoring and administration, it is a potent therapy for the patient with respiratory condition. Oxygen is an expensive medication; thus, it's indication must be met before use.it is used in case of hypoxemia,.. in some airway diseases need less oxygen as compared with other diseases such as copd.

Patients exposed to high oxygen levels for a prolonged period of time have lung damage. The extent of lung damage is dependent on FiO2 and duration of exposure. It is due to intracellular free radicals (such as superoxide, activated hydroxyl ions, singlet O2 and hydrogen peroxide) formed which can damage alveolar-capillary membrane. It starts with increased permeability of the capillaries with resultant edema, thickened membranes and finally to pulmonary fibrosis.thereby hyperoxic lung injury occurs.

oxygen is the only medication with a proven effect in the treatment of diving accidents. After a typical diving accident, administration of oxygen at an inspired concentration (F(I)O(2) 1.0) as high as possible is recommended. Many divers bring along their own oxygen administration systems to the diving sites and these are often better suited for the treatment of diving accidents than the oxygen systems of many emergency responders. Pressure regulators supplying low constant flow oxygen, nasal prongs and inhalation masks are inappropriate. When using artificial ventilation bags with face masks, an oxygen flow of at least 15 l/min should be used.the inspired oxygen concentration should not be decreased, rather the duration of the oxygen administration should be reduced.

In diabetes patients they have low oxygen level in the bloodWhether this lower oxygen uptake capacity is attributed to a low habitual physical activity level, reduced mitochondrial content or an intrinsic mitochondrial defect is a topic of intense debate. indicates that mitochondrial respiration is not abnormal when normalized for mitochondrial content which implies that low habitual physical activity level and/or cardiovascular dysfunction may explain the generally deconditioned state in the Type 2 diabetes patient. Aerobic exercises helps in improving cardiopulmonary functions.