OXYGENATION OBJECTIVES Define oxygenationDescribe oxygen transportation and uptake List factors affecting oxygenation Outline signs and symptoms of hypoxia Explain oxygen administration
definition• Oxygenation is the delivery of oxygen to the body tissues and cells.Physiology of oxygenationThe delivery of oxygen to body cells is a process that depends on the interplay of the pulmonary, hematologic and cardiovascular systems.Specifically, the process involved include: ventilation, alveolar gas exchange, oxygen transport and delivery and cellular respiration
Oxygen transport and delivery• Once the diffusion of oxygen across the alveolar- capillary membranes occurs, the oxygen molecules are dissolved in blood plasma. Three factors influence the capacity of blood to carry oxygen and these are:• The amount of oxygen dissolved in plasma• The amount of hemoglobin• The tendency of hemoglobin to with oxygen
• The oxygen carrying capacity of blood is greatly affected by the presence of hemoglobin in the erythrocytes.• The amount of oxygen carried in a sample of blood is measured in two ways:• Oxygen dissolved in plasma (partial pressure)• Normal partial pressure(PaO2) is 80 to 100mmhg.• The vast majority of oxygen is in the blood bound to hemoglobin molecules
• The amount of oxygen bound in hemoglobin is expressed as percentage of hemoglobin that is saturated with oxygen(SaO2) with 100% being fully saturated.• Normal saturation of arterial blood is about 96 to 98%
FACTORS AFFECTING OXYGENATION• Adequate oxygenation is influenced by many factors including: age, environmental and life style factors and disease process• Age: older adults may exhibit a barrel chest and require increased effort to expand the lungs. Older adults are also more susceptible to respiratory infections because of decreased activity of cilia which normally are effective defense mechanism .
Environmental and lifestyle factors• environmental and lifestyle factors can significantly affect clients oxygenation status.• Clients who are exposed to dust, animal dander, chemicals in the home or workplace are at increased risk for alteration in oxygen• Individuals who experience significant physical or emotional stress or who are obese or underweight are also subject to changes in oxygenation status.• Smokers and second hand smokers are also affected
Disease process• Oxygenation alterations can often be traced to alteration in alveolar gas exchange, oxygen uptake or circulation.• Diseases that may affect oxygenation include: obstructive pulmonary disease, atherosclerosis heart failure, anaemia
Clip showing normal, partially and occluded blood vessel
Physiological response to reduced oxygenation• When oxygen delivery is inadequate to meet metabolic needs of the body, various responses to this deficit can be expected and these include: increased oxygen extraction, anaerobic metabolism, tissue ischemia and cell death.• Signs and symptoms of hypoxia:• Early signs: restlessness , dizziness, increased pulse rate
• If hypoxia remains untreated, the respiratory rate may decline and changes in the level of consciousness may progress to stupor or comma• Perfusion deficits resulting in poor circulation can obviously be noted in the skin cyanosis( bluish discoloration of the skin) which can also easily be seen in the tongue, soft palate and conjunctiva of the eye( these indicate hypoxemia)• Cyanosis of extremities, nail beds and earlobes is often as a result of vasoconstriction and stagnant blood flow.
Clubbing of the fingers which manifests as a flattened angle of thenail bed and rounding of fingertips is a sign of chronic hypoxia
Interventions to improve oxygen uptake and delivery• Oxygen administration• Oxygen uptake in the pulmonary capillary beds can be improved by increasing the concentration of oxygen in the alveolar air and this increases partial pressure of oxygen in the alveoli( PaO2) increase the driving pressure for gas diffusion across capillary membranes.
Complications of oxygen administration• Oxygen administration, like administration of any drug is not without hazard. Clients who have chronic pulmonary disease associated with carbon dioxide retention may become sensitive to carbon dioxide levels to their respiratory rate . These may depend upon chronic low oxygen level in the blood to drive their respiratory drive
• Oxygen toxicity• Prolonged administration of high oxygen levels (greater than 50%) for more than 24 hours may damage the tissue and produce severe respiratory difficulties.• Oxygen can be administered as dry or humidified• Dry oxygen irritates respiratory mucosa• Humidified oxygen is preferred• Administration of high pressured oxygen leads to low oxygen uptake
ADMINISTRATION OF OXYGEN• Definition: it is a procedure that involves giving of oxygen to a patient• Its objective is to supplement oxygen to the vital organs for normal functioning where oxygen is insufficient• Requirements: oxygen concentrator, a bag with the following: nebulizer/bottle of distilled water or normal saline, glass rod and tube fixed on the bottle• Oxygen mask/ nasal canula, tubing catheter, strapping for fixing the catheter
procedure• Explain the procedure to the patient and guardians to gain the patients cooperation and allay anxiety• Position the patient comfortably to promote ease breathing difficulties• Wipe and clear the nostrils to ensure that the airway is clear.
Equipment preparation/environment• Remove all articles that can cause fire around the oxygen giving area.• Create enough space to accommodate equipment• Bring the equipment to the patients bed side• Connect the equipment• Put catheters, strapping and scissors on a tray
method• Wash hands to prevent cross infections• Connect nasal canula• Turn on the oxygen source at prescribed rate(2-6 litres /minute in adults and 2litres/minute in children) to ensure that the patient is getting the required amount• Check that oxygen is flowing through the tube by dipping in galipot of water to see if it is bubbling• If using nasal catheter , measure and mark the length of the catheter to be inserted to make sure it is not too long or too short to ensure adequate delivery of oxygen. Insert catheter about 2cm.
Method continued…….• Strap in the cheek to secure it• If using nasal prongs lubricate the prongs to prevent trauma• Place the prongs in the nostrils to ensure adequate supply of oxygen• Adjust according to size to secure the prongs in position• If using a mask, fit in position by fastening the tapes to ensure optimal supply of oxygen
Method ct….• Make sure the mask covers the mouth and nostrils to ensure full supply of oxygen• Observe the patient closely for color, breathing pattern, to monitor response to therapy. Encourage to breathe normally help him to relax.• Wipe and dry patients face to leave patient comfortable.
After procedure• If mask and canula are reusable:• Decontaminate in appropriate solution• Clean well with soap and water and dry• Send for sterilization• Keep the oxygen set in appropriate place• If mask and canulas are disposble, discard• Document the procedure and observations made.