Respiratory system
Respiratory system is the human body system that is concerned with the what is termed as the pulmonary gaseous exchange; the process involve in the taking in of air containing oxygen and the exchange of such air with that containing carbon dioxide ( Johnson&Lamb,1999). The whole process is a complex process involving the transfer of the oxygenated air from the external sources through the conducting organs and structure to the alveoli where the perfusion takes place. The perfusion is accompanied by the exchange of carbon dioxide, which are a waste product of tissue metabolism and the removal of that gas to the exterior. To achieve the basic goal of the respiratory system, which is, the supply of oxygen to the tissues and the removal of the carbon dioxide to the exterior, the role of the system can be divided into four major functions, which are:
1. Pulmonary ventilation
2. Diffusion of oxygen and carbon dioxide between the lung alveoli and the exterior
3. Transportation of oxygen and carbon dioxide in the blood and body fluid (plasma) to the tissues and away from it
4. Coordination of the ventilation and the other facets of respiration
Respiratory system is made up of different structures, which I will classify as the conducting structures, the structures for the gaseous exchange. The conducting structure are basically those involve in the transition of the gases from or to the exterior to the lungs lobes where the gaseous exchange takes place while those of the gaseous exchange are the structures that takes part in the proper gaseous exchange process( perfusion). Conducting structures are the larynx, trachea, main bronchi, left and right bronchi and then the terminal bronchioles. The structure for the gaseous exchange starts from the respiratory bronchioles, the alveolar ducts, alveolar sacs, pulmonary alveoli.
Respiratory processes
Respiratory process is an intricate process involving various pulmonary and extra-pulmonary structures. The process involves structures like the lungs, the conducting system, the diaphragm, the muscles such as the intercostals muscles and the associated nerves and blood supply and venous drainage. The lungs usually expand in two ways. These are by the downward and upward movement of the thoracic diaphragm to reduce or increase the length of the thoracic or chest cavity, while the second movement entails the elevation and the depression of the ribs to cause expansion and decrease in the anteroposterior diameter of the thoracic cavity. Movement of the diaphragm that is usually the first mostly accompanies normal quiet breathing. The contraction of the diaphragm will cause a downward pull on the inferior surface of the lungs, a process occurring during inspiration. However, during expiration, there is usually relaxation of the diaphragm leading to the elastic recoil of the lung parenchyma, the chest wall and contiguous abdominal structures, which also helps the lungs to propel or expel the gaseous content.
In deep breathing, especially in deep inspiration, the muscle that act during the quite breathing will not be able to expand the lungs so as to raise the rib cage, hence it action is being accompanied by the contraction of some thoracic musculature which are usually termed the accessory muscles of inspiration. Some of these muscles are the serratus anterior, pectoralis minor and the abdominal muscles. These muscles help to the pushes the abdominal contents against the inferior surface of the lungs to forcefully expel the gaseous content of the lungs.
The second method of the thoracic cavity size elevation entails the raising of the ribs to allow the falling back of the sternum hence affecting the anteroposterior diameter of the thoracic cavity. Hence, all the muscles termed muscles of inspiration involves the muscles that help elevate the thoracic cavity while those that reduces the diameter of the rib cage are termed the muscles of expiration. Muscles of inspiration are external intercostals muscles, sternocleidomastoid, serratus anterior, and scalene muscles while those of the expiration involve abdominal recti and the internal intercostals muscles.
Pulmonary ventilation
The movement of air in and out of the lungs is meant for effective gaseous exchange, and one of the basic principles underlying the movement of such air is effect of the difference in the atmospheric pressure and since lungs resemblance to balloons. The following pressures have an effect on the movement of air in and out of the lungs: pleural pressure, alveolar pressure, and transpulmonary pressure.
Oxygen administration
Oxygen administration simply means the administration of oxygen as a form of therapeutic modality, pre or postoperative purpose. The administration of oxygen for either of all the stated use state can be life saving or life threatening hence the administration of oxygen in any clinical or home settings must be done with great care. The major goal of oxygen administration is to supply the lungs adequate oxygen in case of shortage to help provide adequate tissue perfusion. Administration of oxygen can either be in low concentration or high concentration and each depending on where indicated. Excessive or inappropriate use of oxygen can lead to blindness in children, reduction of respiratory drive in the case of emphysema and hypercapnea.
Oxygen can be used as first aid, this mostly seen with patient with obstructive respiratory diseases such COPD and with type II respiratory failure. Patients with myocardiac infarction and hypoxia are assisted with the oxygen administration or therapy. Oxygen for therapeutic purpose are usually in different forms such as liquid form in tanks, compressed gaseous oxygen in cylinders and oxygen concentrator where nitrogen is electrically removed from the air so as to have air with higher concentration of oxygen.
In oxygen administration, there are certain devices that are used. Such devices are categorized under two subheadings as low-flow devices and the high flow devices. Low flow rate devices deliver the oxygen to the patient at a speed or rate, which is quite low, compare the patient inspiratory flow rate, hence the patient can inhale low or high dose of oxygen depending on the patients needs. The low flow devices are nasal cannula, simple oxygen facemask, partial rebreathing mask and non-rebreather masks.
High flow devices deliver the administered oxygen at a very high flow rate, which is usually greater than the patient inspiratory flow rate. The device that is usually used during high flow oxygen administration is the Air-entrainment masks, aerosols mask while tracheostomy collars, T-tube adapters and face tents can also be use with the aerosol masks to deliver high flow rate oxygen (RCJournal.com, 2002). Other special devices are neither classified as high or low flow devices but are important. Those devices are bag-valve-mask, pocket mask, and anesthetic machine.
Oxygen therapy
It involves the administration of oxygen at a concentration greater that of the normal atmospheric air with intent of treating or preventing the symptoms of certain diseases or the manifestations of hypoxia (RCjournal.com, 2002). There are certain indications that bring about the need for oxygen administration such indications are Documented Hypoxia, Acute care situation leading to hypoxemia, severe trauma, acute myocardial infarction, post anesthesia recovery (RCJournal.com, 2002)
Oxygen masks
Oxygen administration can only be achieved effectively only with the use of proper facemask with the indicated oxygen flow rate needed by the patient. The mask represents the means of transferring breathing oxygen gas from the tank where it is stored to the lungs. It can be made up of plastic, silicone or rubber and it can be made to cover the nose and mouth only or the entire face. The types of masks and it use are as follows; plastic masks, usually used in the medical settings where it is mostly used as a therapeutic device. Silicone and rubber masks are used mostly by aviators with the reasons that it provides oxygen supply for longer duration. Most anesthesia oxygen mask are made of rubber and silicone
There is another type of facemask that is known as the aviation passenger masks which is used in most commercial aircraft. This is actually used when there is failure of the cabin pressurization fails which often lead to increase in the risks of hypoxia. There are other types of oxygen facemasks such as those used by the space astronauts, and divers.
Suctioning
Suctioning is part of the procedures under airway management. It is usually performed as a sterile procedure, must be indicated before it is done, and must not be done as a routine procedure. During the procedure evidence of hypoxemia, atelectasis, bronchospasm, cardiac arythmias must be observed. The procedure of endotracheal suctioning is as follows:
· washing of hands so as to reduce cross-infection,
· assessment of the patients needs,
· goggles or face mask uses so as prevent contamination,
· turn on the suctioning apparatus and do the necessary configurations,
· prepare the suction apparatus,
· use in-line suctioning catheter,
· prepare the catheter to be used so also to prevent cross-infection,
· ensure equipment functioning
· open the oxygen device
· replace the oxygen delivery device or reconnect the patient to the ventilator
· applying intermittent suctioning
· replenish the oxygen
· wash the catheter and other associated tubes with normal saline
· monitor the patient vital signs
· after the whole suctioning procedure, keep the catheter
· reposition and reassess the patient
· dispose the suction liners
Trachea care
The care of trachea involves tracheostomy to ease breathing in some patient with respiratory difficulty. Tracheostomy care starts prior to leaving the hospital, that is the patient and his or her family is made to practice the care to show the knowledge and proficiency of the whole procedure
The nurse in charge will have to explain some certain variation that is seen with some type of tube and it accessories. This will help reduce anxiety that accompany transition from hospital to home. The patient should also be made to demonstrate his or her ability to remove and clean the inner cannula. The patient and family will be taught how to clean, change, or use suctioning machine and the signs they should check for when doing it. They should also be taught to take observations of signs like bleeding, signs of infection such as pus, swelling redness warmth. Subcutaneous emphysema and any sign of obstruction must be checked for and report to the doctor if any is seen.
Chest drainage
This involves the removal of unwanted fluid accumulations such as secretions, blood, air mucus that has accumulated in the lungs airways. The aim of the therapy is to relieve pressure that might be hindering the expansion of the lungs and the removal fluid that might predispose the cavity to developing bacteraemia while whole process can start as an emergency or a planned procedure.
The removal or drainage is usually done by inserting a tube through the skin, thoracic musculature and into the thoracic cavity. The tube meant for this purpose is then made to go directly into the pleural portion or cavity of the thoracic cavity. Indications for the therapy include emphysemas, tuberculosis, pyothorax, pneumothorax, hemothorax and surgical procedures. Chest X-rays must be done to view the changes within the pleural cavity and know the extent of the fluid or gaseous collection. The rule of thumb is this, never insert a chest tube when a collapse lung is not life threatening or patient with bleeding disorders.
Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease state characterized by an airflow limitation that is not fully reversible. The airflow limitation is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking. Although COPD affects the lungs, it also produces significant systemic consequences (COPD international, 2004). The disease has been ranked as the fourth leading single cause of death in the world. By year 2000 WHO estimated 2.74 million deaths from COPD (COPD international, 2004).
The pathogenesis of COPD can be classified as reversible and irreversible. Irreversible pathogenesis involves fibrosis and narrowing of the airways, loss of elastic recoil because of alveolar destruction, and destruction of the alveolar support that maintains patency of small airways. Reversible involves accumulation of the inflammatory cells, mucus, and plasma exudates in the bronchi, smooth muscle contraction in peripheral and central airways and subsequent dynamic hyperinflation during exercise.
Management of COPD entails administration of oxygen therapy, use of antioxidants, and pulmonary rehabilitation.
Asthma is chronic inflammatory disease of the airways that causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough. This is associated with widespread and variable bronchoconsrtiction and airflow limitation that is partially reversible. Developed economies might expect to spend 1-2 percent of total health care expenditures on asthma. Developing economies are likely to face increased demand and poorly controlled asthma is expensive; investment in prevention medication likely to yield cost savings in emergency care. It has two components in its pathology; these are hyperactivity and hyperresponsponsivess of the airways leading to inflammation.
Treatment involves the use of three types of drugs, which are preventers, relievers and combination therapy. Preventers are the antileukotrienes, while the controllers are the glucocorticoids. The current statistics are 1 out of 4 Americans have asthma or allergies, approximately 20 million Americans have asthma (AAAA&I, 2008).
References
AAAA&I, (2008). Asthma Statistics. American Academy of Allergy Asthma and Immunology.
Retrieved Nov 28, 2008 from http://www.aaaai.org/media/resources/media_kit/asthma_statistics.stm
Annette, L, Larry J,(1999). Respiratory system; the basics.
Retrieved Nov 28, 2008 from http://42explore.com/respsyst.htm
Bartolome R, (2007). Oxygen therapy.
Retrieved Nov 28, 2008 from http://www.merck.com/mmhe/sec04/ch040/ch040g.html
COPD international, (2004). COPD Statistical Information
Retrieved Nov 28, 2008 from http://www.copd-international.com/library/statistics.htm
RCJournal, (2002). Oxygen Therapy for Adults in the Acute Care Facility — 2002 Revision & Update. AARC Clinical Practice Guideline
Retrieved Nov 28, 2008 from www.rcjournal.com