The respiratory system is composed of the upper and lower respiratory tracts. Together, the two tracts are responsible for ventilation (movement of air in and out of the airways). The upper tract, known as the upper airway, warms and ﬁlters inspired air so that the lower respiratory tract (the lungs) can accomplish gas exchange. Gas exchange involves delivering oxygen to the tissues through the bloodstream and expelling waste gases, such as carbon dioxide, during expiration.
RA is commonly used as the prototype for inﬂammatory arthritis. The incidence rate is approximately 3%, with a two to three times greater incidence in women (Ruddy et al., 2001). In RA, the autoimmune reaction (Fig. 54-3) primarily occurs in the synovial tissue. Phagocytosis produces enzymes within the joint. The enzymes break down collagen, causing edema, proliferation of the synovial membrane, and ultimately pannus formation. Pannus destroys cartilage and erodes the bone. The consequence is loss of articular surfaces and joint motion. Muscle ﬁbers undergo degenerative changes. Tendon and ligament elasticity and contractile power are lost.
Older adults who are dying in the critical care setting need the same quality care as is given to any patient who is facing his or her final days in critical care. Where the care of older adults differs is often in decision making, the consequences of care decisions, and in modifications to symptom management to account for the physiologic changes seen with aging. Good end-of-life care in any setting requires effective communication with the patient and the family, facilitation of decision making, management of complications of the treatment and the disease, symptom control, psychosocial– spiritual care of the patient and the family, and holistic care at the time of death (Foley & Gelband, 2001).
A cerebrovascular accident, or stroke, occurs when a sudden decrease in cerebral blood circulation as a result of thrombosis, embolus, or hemorrhage leads to hypoxia of brain tissues, causing swelling and death. When circulation is impaired or interrupted the small area of the brain becomes infarcted and this changes membrane permeability resulting in increased edema and intracranial pressure (ICP). The clinical symptoms may vary depending on the area and extent of the injury.
Disseminated intravascular coagulation, also known as consumptive coagulopathy, defibrinogenation syndrome, or DIC, is an acute disorder that accelerates the activation of the intrinsic and/or extrinsic cascade clotting mechanism and depletes both clotting factors and platelets. DIC is usually a complication of another disease process in which excessive thrombin is produced, converting fibrinogen to fibrin, and the fibrin creates damaging thrombi in the microcirculation. Fibrin blocks the capillary flow to the organs and results in ischemic tissue damage, and as the clotting factors, platelets, and fibrin split products (FSP) are consumed, hemorrhage and shock results. As the fibrin and FSP repolymerize, a secondary fibrin mesh forms in the microcirculation and when blood travels through this, the red blood cells become damaged and a hemolytic anemia can occur.