Pathophysiology: Concepts of Health and Disease Lecture Notes PDF

Pathophysiology: Concepts of Health and Disease Readings: Chapter 1 & 2 Goodman and Fuller Text Josh TenBensel, PT, DPT 1 Lecture Objectives The student will be able to: Define the following terms: health, impairment, di...

Pathophysiology: Concepts of Health and Disease Readings: Chapter 1 & 2 Goodman and Fuller Text Josh TenBensel, PT, DPT 1 Lecture Objectives The student will be able to: Define the following terms: health, impairment, disability, handicap, illness, disease, pathology, pathophysiology Explain the attributes of acute vs. chronic disease/illness Describe the similarities and differences in the Nagi and ICF Disablement models, and their relevance to PT practice Describe the Biomedical vs. Biopsychosocial Healthcare perspectives of illness and disease Describe the different theories of disease etiology Explain the leading causes of death and the role of disease prevention Know and be able to describe the 3 levels of disease prevention. Discuss the costs of healthcare in the U.S. Explain the role of physical therapists in promoting health Explain why physical therapists need a fundamental understanding of pathology and pathophysiology 2 What is Health? The World Health Organization (WHO) defines health as a state of complete physical, mental and social well-being; not merely the absence of disease. Health is “a resource for everyday life.” Ability and desire to do what one wants to do in life with energy, vitality, enjoyment, and satisfaction Origin of the word “health” comes from words meaning “wholeness” or “wellness.” 3 Health and Wellness Continuum Special Implications for the Therapist 1.1 page 4 Goodman and Fuller 4 Signs, symptoms and syndromes Signs, symptoms, syndrome, disorder, disease. Terms used as a hierarchy to classify how our health is affected. The signs are visible findings that are apparent to the practitioner. The symptoms are the things patients notice that indicate there might be a problem. When a group of signs and symptoms occur together, they may be classified as a syndrome. In therapy we will commonly say a patient has signs and symptoms consistent with a disorder. Example s/s of a clinical syndrome or disorder or a more specific disease process. A disorder might indicate that a specific disease is possible but there may not enough clinical evidence for diagnosis. A disease is a pathological process that healthcare providers are able to see, touch, and measure. Diseases have particular signs and symptoms 5 Syndrome, Disease and Illness Syndrome vs. Disease Syndromes are groups of symptoms associated with a disease. Knowing the syndrome can help diagnose the disease. Disease vs. Illness Illness is a broad concept while disease refers to a specific condition that can be diagnosed by a healthcare provider. In looking at disease versus illness, the term illness is more subjective. You may identify as being ill based on your symptoms. Some of your symptoms can be fleeting like a runny nose, and others can be more serious and long term like high blood pressure. When you have a disease, you have a specific condition that was determined by your healthcare provider, and it is more objective https://www.verywellhealth.com/disease-vs-disorder-5092243 6 Disease vs. Illness Disease Biological or psychological alteration that results in a malfunction of a body organ or system A biomedical condition (objective data) Can occur without an individual perceiving illness Example: Hypertension Illness Is a real or perceived deviation from a healthy state The perception of, and response to, not being well A person can be ill even though no obvious pathologic process can be identified A broader concept than the disease Examples: COVID-19 vs. Dementia 7 Acute vs. Chronic Disease/Illness Acute  Rapid onset, short duration (NOT Necessarily Severe)  Usually self limiting or responds to treatment  Full recovery anticipated  Examples: Infectious disease, trauma Subacute  Describes a time course that is between acute and chronic.  A symptom that is subacute has been present for longer than a few days but less than several months. Chronic  Permanent (perpetual; long lasting) impairment or disability  Residual physical or cognitive disability  Requires special rehabilitation and long-term management  May fluctuate in intensity  Examples: Diabetes mellitus, heart failure 8 Incidence vs. Prevalence & Morbidity vs. Mortality Incidence is a measure of the number of new cases of a characteristic that develop in a population in a specified time period; whereas prevalence is the proportion of a population who have a specific characteristic in a given time period, regardless of when they first developed the characteristic. Morbidity refers to suffering from (being symptomatic) or having a specific illness or health condition It is usually represented or estimated using prevalence or incidence. Mortality refers to the number of deaths that a specific illness or health condition caused. 9 Natural History, prognosis and outcomes The natural history of a condition, disorder, or disease describes how it progresses over time. Predictive factors assist with prognosis and outcome Predictive factors can be both positive and negative 10 Disease Prevention Primary Prevention – removing or reducing disease risk factors Regular Exercise, calcium supplementation Secondary Prevention – efforts of early detection and prevention of further complication Colon cancer screening, regular physical examinations (hypertension) Tertiary prevention – limiting impact of established disease Goal: Return patient to highest level of function possible and prevent severe disabilities One of the main dimension in which PTs participate Special Implications for the Therapist 1.2 page 8 Goodman and Fuller 11 Disease Prevention Primary Prevention – removing or reducing disease risk factors Regular Exercise, calcium supplementation Primary prevention involves preventing disease in a susceptible or potentially susceptible population through general health promotion. Secondary Prevention – efforts of early detection and prevention of further complication Colon cancer screening, regular physical examinations (hypertension) Secondary Prevention-Risk factor assessment to determine appropriate intervention strategies focused on reducing or preventing the chance of progression to disease. Tertiary prevention – limiting impact of established disease Goal: Return patient to highest level of function possible and prevent severe disabilities One of the main dimension in which PTs participate Tertiary care/prevention is provided in highly specialized, complex, and technologically based settings (e.g., transplant services, burn units, emergency departments) or when supplying specialized services (e.g., to clients with spinal cord lesions or closed-head trauma) in response to requests for consultation made by other health care practitioners after the patient has the disease or condition. Special Implications for the Therapist 1.2 page 8 Goodman and Fuller 12 13 The Leading Killers 70% of all deaths Heart Disease Respiratory Accidents Diabetes Disease Cancer Stroke Tobacco Use 435,000 Physical Inactivity Unhealthy Diet } 400,000 Excessive Alcohol Use 85,000 Lifestyle factors are the primary contributors to 6 of the leading causes of death 14 https://www.cdc.gov/nchs/data/databriefs/db492-tables.pdf#4 Cost of Healthcare in U.S. U.S. spends more on healthcare per person than any other industrialized nation Annual healthcare costs exceeded $10,000 per person for first time in 2015 Were projected to be > $12,000 by 2025, currently > $13,000 in 2022 In 2000 the U.S. healthcare system ranked 37th in world (WHO) Last among the 11 high income countries in 2021 Emphasis (over-emphasis?) on state-of-the-art cures rather than disease prevention Lifestyle-related disease is the single biggest cost in the U.S. healthcare system https://www.cms.gov/data-research/statistics-trends-and-reports/national-health-expenditure-data/nhe-fact-sheet https://www.commonwealthfund.org/publications/fund-reports/2021/aug/mirror-mirror-2021-reflecting-poorly 15  How are Americans Doing? Reeves and Rafferty – survey of more than 153,000 American adults Index with 4 healthy lifestyle characteristics Nonsmoking Healthy weight (BMI of 18.5 to 25.0) Consuming 5 or more servings of fruits and vegetables per day Regular physical activity (equal to or greater than 30 minutes, 5 or more times per week). Now Identified as 5 with 3 being emerging Physical activity: Getting at least 150 minutes of moderate physical activity per week Diet: Eating a healthy diet with a Healthy Eating Index score of at least 60.0 Weight: Maintaining a healthy body weight with a body mass index (BMI) of 18.5–24.9 Alcohol: Limiting alcohol consumption to 7 drinks per week for women and 14 drinks per week for men Smoking: Avoiding tobacco use and exposure Sleep: Getting enough restorative sleep Mental health: Managing mental health and reducing stress Other healthy behaviors include getting an annual physical examination. https://www.cdc.gov/nchs/data-linkage/mortality-public.htm 16 Reeves and Rafferty Arch Intern Med. 2005;165:854-857  How are Americans Doing? Results: 24% were smokers11.5% 60% were overweight or obese 72% 77% consumed < 5 fruits and vegetables per day90% 78% reported not enough regular physical activity50% How many Americans reported following all 4 healthy lifestyle characteristics? Only 3%  2.7% How many of these characteristics do you personally practice? Li Y, Xia PF, Geng TT, Tu ZZ, Zhang YB, Yu HC, Zhang JJ, Guo K, Yang K, Liu G, Shan Z, Pan A. Trends in Self-Reported Adherence to Healthy Lifestyle Behaviors Among US Adults, 1999 to March 2020. JAMA Netw Open. 2023 Jul 3;6(7):e2323584. Reeves and Rafferty Arch Intern Med. 2005;165:854-857 17 APTA Positions on Health Promotion and Wellness “PTs are uniquely qualified to assume leadership positions in efforts to prevent injury and disability, and fully supports the positive roles that PTs play in the promotion of healthy lifestyles, wellness, and injury prevention.” – APTA House of Delegates Priority Goals of the Association Goal II - “Physical Therapists are universally recognized and promoted as providers of fitness, health promotion, wellness and risk reduction programs for persons across the life-span to enhance quality of life.” 18 Theories of Disease Etiology Etiology is the study of causation or origination Germ Theory Disease caused by specific pathogens Biomedical Model Malfunctioning organs and cells Psychosocial Theory Psychosocial interactions influence susceptibility to disease Homeostasis Theory Body’s ability to maintain its internal environment in a constant state of equilibrium despite external influences that promote imbalance (i.e., steady state) 19 Theories of Disease Etiology Psychoneuroimmunology (Mind-body connection) Neural, endocrine and immune system interactions Genes (genetic variations, defects or alterations) increase susceptibility or cause disease ≈ 4,000 diseases thought to be caused by inherited gene mutations Most diseases are a combination of genetic, environmental and behavioral interactions “Genetics loads the gun, environment and lifestyle pull the trigger.” Multicausal Theory 20 Multicausal Disease Theory 21  Multicausal Disease Theory Applied to Cardiovascular Disease http://file.scirp.org/Html/5-1910299_42122.htm 22 Biomedical vs. Biopsychosocial Healthcare Biomedical perspective Focus is on physical/physiological symptoms and illness (i.e., the diagnosis and treatment of disease) Lifestyle and prevention are not a main focus Responds very effectively to infectious disease, acute illness, and trauma Health and disease often viewed independently from other dimensions of life Not a “holistic” model of care Biopsychosocial perspective (wellness model) Takes a multidimensional approach to health Emotional, social, and spiritual areas of a person’s life influence health and well-being Focus is on quality of life and vitality 23 The Biopsychosocial Model Biologic Overall structure and function of the individual’s cells, tissues, organs and body systems Psychologic Individual’s mood, emotions, and personality Sociologic Individual’s relationships and interactions with others and the environment Spiritual (Biopsychosociospiritual) Individual’s sense of meaning and purpose for existence; personal values and morals; religious beliefs 24 Disablement Models Describe the effects of disease and injury at the level for the person and at the level of society Different models try to define inter-relationships between: Diseases, Impairments, Functional limitations, Disabilities, Handicaps, Effects of the patients environment A helpful way to classify individuals from a PT (rehab) perspective Provides a basis for patient management Disease, Illness, Health and Disability 25 Impairment, Disability, Handicap The words impairment, disability and handicap are often used interchangeably; however, they have different meanings. The differences in meaning are important for understanding the effects of a disease or injury. The most commonly cited definitions are those provided by the World Health Organization (1980), as defined in the following slide. These are the "testable" definitions 26 Impairment, Disability, Handicap Impairment: any loss or abnormality of psychological, physiological, or anatomical structure or function Disability: any restriction or lack of ability (resulting from an impairment) to perform an activity in the manner or within the range considered normal for a human being Handicap: a disadvantage for a given individual that limits or prevents the fulfillment of a role that is normal 27 Impairment, Disability, Handicap As traditionally used: Impairment refers to a problem with a structure or organ of the body Disability is a functional limitation with regard to a particular activity Handicap is a disadvantage in filling a role in life relative to a peer group. http://www.pediatrics.emory.edu/divisions/neonatology/dpc/Impairment%20MX.html 28 Cerebral Palsy Example David is a 4-yr.-old who has a form of cerebral palsy (CP) called spastic diplegia. David's CP causes his legs to be stiff, tight, and difficult to move. He cannot stand or walk. Impairment: Inability to move legs easily at joints and inability to bear weight on feet due to the structural issues is an impairment. Without orthotics and surgery to release abnormally contracted muscles, David's level of impairment may increase as imbalanced muscle contraction over a period of time can cause hip dislocation and deformed bone growth. http://www.pediatrics.emory.edu/divisions/neonatology/dpc/Impairment%20MX.html 29 Cerebral Palsy Example David is a 4-yr.-old who has a form of cerebral palsy (CP) called spastic diplegia. David's CP causes his legs to be stiff, tight, and difficult to move. He cannot stand or walk. Disability: David's inability to stand or walk are one type of disability. His level of disability can be improved with physical therapy and special equipment. For example, if he learns to use a walker or with braces, his level of disability will improve considerably. http://www.pediatrics.emory.edu/divisions/neonatology/dpc/Impairment%20MX.html 30 Cerebral Palsy Example David is a 4-yr.-old who has a form of cerebral palsy (CP) called spastic diplegia. David's CP causes his legs to be stiff, tight, and difficult to move. He cannot stand or walk. Handicap: David's CP is handicapping in that it prevents him from fulfilling a normal role at home, in preschool and in community. His handicap level presently is very mild as he has been well-supported to be able to play with other children, interact normally with family members and participate fully in family and community activities. As he gets older, his handicap will increase where certain sports and physical activities are considered "normal" activities for children of the same age. http://www.pediatrics.emory.edu/divisions/neonatology/dpc/Impairment%20MX.html 31 Disablement Models Nagi International Classification of Functioning, Disability and Health (ICF) Previously referred to as “International Classification of Impairments, Disabilities, and Handicaps” 32 Nagi's Disablement Model Describes process of disablement, dating from Nagi's publications in the 1960's Nagi described four categories of disablement: Active Pathology Impairment Functional limitations Disability 33 Nagi's Disablement Model 34 Nagi's Disablement Model Active Pathology – interruption or interference with normal processes, and efforts of the organism to regain normal state Primarily identified at the cellular level (Tissue) Typically a physician diagnosis Example: diabetes, coronary artery disease, etc. 35 Nagi's Disablement Model Impairment – a loss or abnormality at the tissue, organ, and body system level. An abnormality in structure or function. The anatomical, physiological, mental or emotional abnormalities or loss. Results from underlying changes in the normal state Indicated by signs/symptoms Examples: abnormal muscle strength, abnormal range of motion, abnormal gait 36 Nagi's Disablement Model Functional limitations – restrictions in the performance of specific tasks by a person. The result of inability to perform actions, tasks and activities that constitute “usual activities” for an individual How active pathology and impairment affects function and the ability to move. Measured at the level of the person (movements that the person needs to perform) Examples: Difficulty getting out of bed 37 Nagi's Disablement Model Disability – limitations in performing socially defined roles and tasks expected of an individual within a sociocultural and physical environment. The inability or restricted ability to perform actions, tasks and activities related to self-care, work, community, leisure, etc. Occurs when person cannot overcome functional limitations to perform “normal” activities and roles How the injury, disease or illness affects person's role and participation in society Example: Inability to bathe oneself. How does this affect the person's role in society? 38 International Classification of Functioning, Disability and Health (ICF) World Health Organization (WHO) Universal classification from 1980; modified slightly since (2001 & 2003) Describes health and function in a more “neutral” language Similar concepts as Nagi but the terminology differs Classifies functioning and disability associated with health conditions Health condition: is there an underlying disorder or disease? Functioning: non-problematic or neutral aspects of health Disability: impairments, activity limitations or participation restrictions Videos on Sakai-ICF models 39 ICF http://www.who.int/classifications/icf/en/ 40 ICF Health Condition – diagnosis of disease Similar to active pathology in Nagi Disorder, disease, injury, trauma or congenital anomaly Examples: Spinal cord injury; diabetes 41  ICF Body Functions – physiological functions of body systems (including psychological functions), such as hearing, vision, pain sensation, muscle strength, joint mobility Includes all physical, physiological and psychological factors that impact a person’s body in the orientation process. An impairment (aka Nagi) of body function  something doesn’t work correctly in the body Examples: Reduced shoulder range of motion; impaired somatosensation in feet 42 ICF Body Structures – anatomical parts of the body such as organs, limbs and their components Examples: brain, peripheral nerves, cardiovascular system, muscles Something is missing or altered – amputation 43 ICF Activity – the execution of a task or action by an individual Activity Limitations – difficulties an individual may have in executing activities Examples: difficulty walking up stairs, unable to lift a glass of water, unable to safely walk in house, unable to dress self 44 ICF Participation – involvement in life situations Are the interactions between features of person (body and mind) and features of the overall context in which the person lives (social, environmental). Examples: working, attending a social event, doing house chores, driving a car Participation restrictions Example: inability to perform a job, drive car to store How issues of structure and function can impair/limit participation Example: Brain injury  short-term memory loss  can’t perform duties at job. Example: Spinal cord injury  can't care for infant child 45 ICF Environmental Factors – composed of the physical, social and attitudinal environment in which people conduct their lives Examples: Natural environment and human-made environment; social support and relationships; patient attitudes Personal Factors – background of person’s life Example: Age – ability to heal, declining endurance, muscle power, heart rate, etc. Example: Gender – relate between genders Example: Coping styles – premorbid psychological profile Example: Education – ability to interpret the world around Example: Past and current experience 46 ICF Implementation: Example http://www.cram.com/flashcards/pt6001-physical-therapist-practice-2604257 47 Dimensions of Disability Disability has three dimensions: 1.Impairment in a person’s body structure or function, or mental functioning; examples of impairments include loss of a limb, loss of vision or memory loss. 2.Activity (Abilities)/Activity limitation, such as difficulty seeing, hearing, walking, or problem solving. 3.Participation (Abilities)/Participation restrictions in normal daily activities, such as working, engaging in social and recreational activities, and obtaining health care and preventive services. 48  Nagi ICF Active pathology – interruption or Health conditions – diseases, disorders, and interference with normal processes, and injuries effort of the organism to regain normal state Body function – physiological functions of body systems Impairment – anatomical, physiological, Body structures – anatomical parts of the body mental, or emotional abnormalities Impairments – problems in body functions or structure Activity – the execution of a task or action by Functional limitation – limitation in an individual performance at the level of the whole organism or person Activity limitation – difficulties an individual may have in executing activities Participation – involvement in a life situation Disability – limitation in performance of socially defined roles and tasks within a Participation restriction – problems a person sociocultural and physical environment may experience in involvement in life situations 49 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759568/ What is Pathology and Pathophysiology? Pathology From Greek pathos = suffering and logos = study of Study and understand structural and functional changes in cells, tissues, organs and body systems that underlie human disease A departure or deviation from a healthy, normal, or efficient condition or function Disruption of homeostasis Causes, progression, and consequences of disease Clinical manifestations or signs and symptoms of disease Pathophysiology – is the physiology of disordered function that arises from pathology 50 Why Study Pathology/ Pathophysiology? How does this particular disorder or disease effect this person’s functional abilities and functional outcomes? What precautions should be taken when someone with this condition is exercising or when applying therapeutic modalities? For this disease, what vital signs should be monitored during therapy? How will understanding normal physiology and pathology affect the treatment plan or intervention? When should I refer this patient? 51 Questions? 52