Also found in: Dictionary, Thesaurus, Financial, Acronyms, Encyclopedia, Wikipedia.
Severe curtailment of oxygen, as during ascent to high altitudes or in certain illnesses, may bring on a variety of symptoms of hypoxia, or oxygen lack. A number of poisons, such as cyanide and carbon monoxide,, as well as large overdoses of sedatives, disrupt the oxygen distribution system of the body. Such disruption occurs also in various illnesses, such as anemia and diseases of lungs, heart, kidneys, and liver.
Another serious complication of high-oxygen concentration therapy is the development of a hyaline membrane because of a deficiency of pulmonary surfactant; surfactant is vitally important to normal expansion and deflation of the alveoli. Prolonged exposure to inspired oxygen concentrations in excess of 50 per cent can impair the production of this surfactant in a patient of any age. The result is a loss of lung compliance and reduction of the transport of oxygen across the alveolar membrane.
The danger of oxygen toxicity can be minimized by careful assessment of each patient's need for oxygen therapy and systematic blood gas analysis to determine patient response and effectiveness of treatment. Symptoms of oxygen toxicity are substernal distress, nausea and vomiting, malaise, fatigue, and numbness and tingling of the extremities.
The delivery of appropriate and effective oxygen therapy requires frequent monitoring of arterial blood gases. An initial blood gas analysis at the time the therapy is started provides baseline data with which to evaluate changes in the patient's status.
In addition to monitoring blood gases to assess the patient's need for and response to supplemental oxygen, it is helpful to observe the patient closely for signs of hypoxemia. However, these signs are not as reliable as blood gas analysis because the clinical manifestations of hypoxemia vary widely in individual patients. The typical clinical manifestations of hypoxemia are confusion, impaired judgment, restlessness, tachycardia, central cyanosis, and loss of consciousness.
The clinical signs and symptoms of hypoxemia may vary from patient to patient, and they should not be depended upon as valid indications of oxygen insufficiency. This is especially true of cyanosis, a symptom that depends on local circulation to the area, the red cell count, and hemoglobin level. In addition to the data obtained from blood gas analyses, an oxygen analyzer should be used occasionally to check inspired oxygen concentration.
In general, the dosage and mode of administration fall into the following categories. High concentrations above 50 per cent usually are prescribed when there is a need for the delivery of high levels of oxygen for a short period of time to overcome acute hypoxemia, as in cardiovascular failure and pulmonary edema. The flow rate may be as high as 12 liters per minute, administered through a close-fitting face mask with or without a rebreathing bag, or via an endotracheal tube.
Moderate concentrations of oxygen are indicated when the patient is suffering from impaired circulation of oxygen, as in congestive heart failure and pulmonary embolism, or from increased need for oxygen, as in thyrotoxicosis, in which the increased metabolic rate creates a need for more oxygen. The rate of flow should be 4 to 8 liters per minute, administered through an air entrainment mask that delivers concentrations above 23 per cent, or in a dosage of 3 to 5 liters per minute through a nasal cannula.
Low concentrations of oxygen are indicated when the patient is receiving oxygen therapy over an extended period of time, as in chronic obstructive pulmonary disease, and there is the possibility of hypoventilation and the danger of increased CO2 retention. The rate of flow should be 1 to 2 liters per minute, administered through a nasal cannula, or via an air entrainment mask that delivers 24 to 35 per cent oxygen.
Other methods of oxygen administration include the nasal catheter and the oxygen tent. The nasal catheter can cause some discomfort to the patient, and since it is no more and no less effective than the cannula, most therapists and patients prefer not to use it. The oxygen tent is considered by many to be obsolete, its use being limited to the administration of oxygen to children who cannot or will not tolerate other modes of delivery, and to children in whom the objective is to provide oxygen and humidity or humidity alone.
Oxygen is not an explosive gas, but it does support combustion and presents a serious fire hazard. All electrical equipment should be checked for defects that could produce sparks. All appliances that transmit house current must be kept outside an oxygen tent, and all equipment with exposed switches and meters must be considered potential sources of fire. Static electricity is a minimal risk which can be further reduced by maintaining a relatively high humidity in the oxygen tent. Smoking in the immediate area of oxygen administration is prohibited and there should be signs informing visitors and others of this restriction.
When the patient is wearing a mask for an extended period of time, discomfort can be minimized by removing the mask and washing and drying the face at least every eight hours. To be effective the mask must fit snugly and follow the contour of the face. This means that reddened areas will appear where the mask has pressed against the skin. These areas should be gently massaged and the skin lightly powdered to reduce friction.
A program of infection control is especially important in the prevention of cross-infection from the equipment that is used to administer oxygen. Humidifiers and nebulizers may serve as sources of infection because they provide a medium for the growth of bacteria and molds. There is less danger of this happening when disposable equipment is used, but this does not preclude the need for a systematic development of policies and procedures to prevent and control the spread of infection. Every person involved in the care of the patient must be aware of this program and cooperate in its implementation.
The transcutaneous electrodes are heated to encourage an adequate supply of blood to the area of skin to which they are attached and remain in place to permit continuous monitoring of arterial oxygen levels. To avoid burns, the electrode site can be changed every two hours. An ongoing record provides information about the neonate's oxygen level at any given moment. It allows caregivers to observe the neonate's response to handling and other procedures that may require modification to avoid severe anoxia. Placing the electrodes at specific sites can also aid the diagnosis of patent ductus arteriosus.
Patient discussion about O
Q. My 11 y/o son eyes appear to have a slight yellow in the whites toward the corners. I am assuming he will need blood work, but does anyone have any idea what may be the cause?
If your child is generally healthy, and this change appeared without any overt problem (e.g. liver disease or blood problem), or your child had fever or fasted recently, this jaundice may represents Gilbert syndrome. It's a syndrome of slightly elevated levels of bilirubin, and considered not dangerous.
You may read more here:http://www.nlm.nih.gov/medlineplus/ency/article/000301.htm
Q. How can you tell that your depressed? and when you find out you are, can you get treatment w/o parents consent I believe i am depressed.. i want to get help but i don't want to go to my parents. They are not the greatest and i want some sort of medicine. I was just wondering if i could get a over the counter medicine for cheap...