COPD PDF

Clinical Sciences: Medical and Neurological conditions Chronic Obstructive Pulmonary Disease COPD Tony Wong Assistant Professor of Practice, PolyU Intended Learning Outcome After this lecture, the students should be able to understand: the normal proce...

Clinical Sciences: Medical and Neurological conditions Chronic Obstructive Pulmonary Disease COPD Tony Wong Assistant Professor of Practice, PolyU Intended Learning Outcome After this lecture, the students should be able to understand: the normal process of Respiration what is COPD Pathology Clinical course Features Assessment of COPD management of COPD Pharmalogical management Non-pharmalogical management  Healthy Lungs vs COPD Lungs https://images.squarespace-cdn.com/content/v1/5e9e7873f15ec443bd66cd3c/1601241609055-VABM12M4GGLWCCSJXUP9/Healthy+vs+COPD+lungs+960px.jpg Healthy Lungs VS COPD Lungs Obstructive Chronic Bronchitis Airway size marked decrease to 20 – 25 % = lumen Emphysema Damage of lung tissue of alveoli, making the air sacs unable to maintain the shape upon exhalation Air exchange cannot take place and air becomes trapped Spirometry Most of the setting checked by nurse Spirometry is a method of assessing lung function by measuring the total volume of air the patient can exhaled from the lungs after a maximal inhalation Even inhale a lot, insufficient O2 -> affect daily life * Terminology about Lung Function test FEV1 – Forced Expiratory Volume in One second: The volume of air expired in the first second of the blow FVC - Forced Vital Capacity: The total volume of air that can be forcibly exhaled in one breath (X time limitation) FEV1/FVC ratio: The fraction of air exhaled in the first second relative to the total volume exhaled VC - Vital Capacity: A volume of a full breath exhaled in the patient’s own time and not forced. Often slightly greater than the FVC, particularly in COPD FEV6 – Forced expired volume in six seconds: Often approximates the FVC. Easier to perform in older and COPD Insufficient exhale effort -> use max time to check how is affected patients but role in COPD diagnosis remains under investigation EELV - End Expiratory Lung Volume Minimise the capacity of total lung function DH - Dynamic Hyperinflation “ can be defined as “a fixed increase of EELV above the normal or resting value during exertion The nearby lung muscles may not be strong enough to carry out strong exertion Obstructive pattern (X 100% bcz lung shape) Bronchodilator Reversibility test for symptom relief General rule: spirometry that becomes normal after bronchodilator is NOT COPD To determine whether fixed airway narrowing is present For patient with COPD, post-bronchodilator FEV1/FVC remains symptoms will subside Increased airway responsiveness to a variety of stimuli Symptoms Diffuse wheezing Dyspnea Cough Resulting from spasmodic contractions of the bronchi  Differential Diagnosis: COPD and Asthma COPD Asthma Onset in mid-life >50yo Onset early in life (often childhood) Symptoms slowly progressive Symptoms vary from day to day Relatively low temp + accumulation of mucus Long smoking history Symptoms worse at night/early morning Allergy, rhinitis, and/or eczema also present Family history of asthma *Classification of Severity of airflow limitation Highlight in red is very important in COPD Stage Features Lung function I: Mild COPD Intermittent symptoms FEV1 ≥ 80% predicted II: Moderate COPD Persistent symptoms; with disability 50% ≤ FEV1 ≤ 80% predicted III: Sever COPD Frequent exacerbations 30% ≤ FEV1 ≤ 50% predicted IV: Very Severe COPD Chronic respiratory failure FEV1 < 30% predicted Based on Post-bronchodilator FEV1 (GOLD-Global Initiative for Chronic Obstructive Pulmonary Diseases, 2011) Assessment of Symptoms COPD Assessment Test (CAT): An 8-item measure of health status impairment in COPD (http://catestonline.org) Stage 3&4: difficulty in bathing and other ADLs Assessment of Symptoms (2) Breathlessness Measurement using the Modified British Medical Research Council (mMRC) Questionnaire: relates well to other measures of health status and predicts future mortality risk. *Modified British Medical Research Council Highlight red (mMRC) Questionnaire Grade 0-4, Stageing 1-4  Symptoms may be Combined Assessment of COPD easily subsided by medications Patient is in one of 4 categories: A: Less symptoms, low risk B: More symptoms, low risk C: Less symptoms, high risk D: More symptoms, high risk GOLD 2011 Additional Investigations Chest X-ray: Seldom diagnostic but valuable to exclude alternative diagnoses and establish presence of significant comorbidities Lung Volumes and Diffusing Capacity: Help to characterize severity, but not essential to patient management Oximetry and Arterial Blood Gases (ABG): Pulse oximetry can be used to evaluate a patient’s oxygen saturation and need for supplemental oxygen therapy Exercise Testing: Objectively measured exercise impairment, assessed by a reduction in self-paced walking distance (such as the 6 min walk test) or during incremental exercise testing in a laboratory, is a powerful indicator of health status impairment and predictor of prognosis Exacerbations An acute change in dyspnea, cough and/or sputum sufficient enough to warrant therapy change Symptom at least TWO of: Increase in SOB, 痰 Sputum purulence, Sputum volume Or any one of above and one of: URTI, Wheeze, Cough, Increase in resp/pulse rate Risk of Exacerbations To assess risk of exacerbations use history of exacerbations and spirometry: TWO or more exacerbations within the last year OR an FEV1 < 50% of predicted value are indicators of high risk Common cause of Acute Exacerbation (AECOPD) Viral, bacterial infection Environmental factors such as Temp, Air quality Sudden drop of temp -> more severe contractions of airways Quit Smoking Smoking cessation has the greatest capacity to influence the natural history of COPD. Health care providers should encourage ALL patients who smoke to quit Pharmacotherapy and nicotine replacement reliably increase long- term smoking abstinence rates Pathology for Acute Exacerbation of COPD Normal trace showing FEV1 & FVC (Vol-Time chart-spirometry) chronic obstructive pulmonary disease (COPD) Major cause for COPD is SMOKING COPD refers to the obstruction or narrowing of respiratory tract caused by long- term damage to the respiratory system. causes symptoms such as hypoxia (lack of oxygen), breathlessness and coughing. COPD patients may even have difficulties in their normal daily activities. NO CURE for COPD & deteriorate gradually over time. the condition can be improved by early treatment. or to quit smoking help prevent the disease. -> stabilise (e.g. stay @stage 1 & X proceed further worse) Pathology COPD is mainly the condition of airways obstruction caused by emphysema or chronic bronchitis. Emphysema refers to the swelling and damaging of alveoli (air sacs) at the tips of bronchioles, reducing the area for gases exchange of O2 & CO2 effectively. =/= COPD bcz bronchitis is reversible Chronic bronchitis refers to the inflammation of mucus membranes in the bronchi, causing an increased production of secretion which blocks the airways. it leads to symptoms of coughing and shortness of breath. lung tissues and function cannot recover completely once they are damaged, therefore COPD cannot be cured completely. Risk factors of COPD Smoking Passive smoking Air pollution Indoor pollution Long term exposure to fumes and dust in the working environment Congenital anti-protein enzyme deficiency Common symptoms Coughing for long term (more than months) Lots of sputum Shortness of breath, especially during physical exercises (on exertion) Difficult in breathing Decreased physical capacity and activity tolerance Hypoxia (severe lack of oxygen) with blue discolouration of lips, hands and feet Early COPD does NOT have obvious symptoms. But as the lung function is increasingly damaged, patient with moderate to severe stage of disease would experience shortness of breath, decreased activity or even hypoxia. Diagnosis Pulmonary function test common way to diagnose COPD. By the data obtained from blowing air into the Spirometry for a few times, patient’s lung capacity and the exhalation speed are shown for diagnosing whether the patient has COPD. Pulmonary function test is also commonly used for assessing the progress of the disease. Chest X-ray Chest X-ray can be used for the diagnosis of advanced stage emphysema. Doctor usually uses chest X-ray to examine and rule out other lung or heart diseases, e.g. tuberculosis and lung cancer. Arterial blood gas (ABG) analysis Doctor will take the blood from patient’s artery to analyze the levels of oxygen and CO2 contained in blood. This test has a certain degree of risk and is usually used to patient with more severe COPD to determine whether the patient needs long-term oxygen therapy (LTOT). Clinical use of oximeter to measure the oxygen level via skin Sputum examination Sputum examination is used to rule out the possibility of other lung diseases, e.g. lung cancer and tuberculosis. When the condition of COPD patient gets exacerbated (i.e. more sputum with pus and difficulty breathing), the sputum can be used for bacterial examination, which helps the diagnosis and treatment. Respiratory tract URTI COPD Definition of COPD COPD, a common preventable and “treatable” disease, is characterized by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases Exacerbations and comorbidities contribute to the overall severity in individual patients Features Air-flow obstruction that is NOT fully reversible and usually progressive Related to clinical diseases, e.g. chronic bronchitis, emphysema Associated with systemic manifestation Muscle wasting Co-morbidities, e.g. cor-pulmonale Symptoms Cough, sputum, dyspnea (shortness of breath, SOB) Pathology Related to abnormal inflammatory responses to noxious stimuli, e.g. smoking Problems for people with COPD (ICF) Long term insufficient O2 to organs and muscles will affect overall health Treatment** highlight in red only relieve Ssx, X return to normal Medication can help improve the condition of patient and mitigate the impact of the disease to the patient’s daily life. Common medication includes: Bronchodilators: relax the muscles in the airway, resulting in airway dilatation and ease the symptoms. There are two types of bronchodilators, oral and metered dose inhalers. Metered dose inhaler can deliver the puff of medication into the airway directly. If the inhalation method is correct, the dosage needed can be smaller than that of oral bronchodilator, and also the side effects of medication, e.g. palpitation, shaky hands, sleeplessness, headache, dry mouth and muscle cramp can be reduced. Suppress immune system (bcz mucus and sputum which are produced due to inflammation blocks the airway) Steroids: can reduce airway inflammation, but not all patients will get better after using it. Prolonged use of oral steroids may have side effects of weakened immunity and osteoporosis; while using spray steroids may cause sore throat, but it has fewer side effects on the whole body than those of oral steroids. Antibiotics: doctor will prescribe drugs to patient with bacterial infections to control the condition. Long-term oxygen therapy (LTOT) long-term oxygen therapy to patient with severe insufficiency of oxygen. After assessment by therapist, patient should install oxygen concentrator and carry portable equipment when going out. Patient should follow the prescription on using the appropriate concentration of oxygen (Litre) and should not adjust it on his/her own discretion. Pulmonary rehabilitation How to cope with ADL e.g. bathing, esp stage 3-4 It can reduce the need for hospitalization and improve the quality of life. The treatment generally includes teaching of skills of controlling asthma, breathing exercise, methods of removing sputum (e.g. expectoration posture and skills), coordination of respiration and body movements, physical exercise, energy saving, stress managing skills and recommendations for diet. Pulmonary rehabilitation team included physiotherapists, occupational therapists Surgery Some of the patients with severe emphysema may need surgery to remove part of the lungs. there is new surgery treatment by using bronchoscope to implant a small valve in a specific bronchus which collapses the corresponding lobe of lung to alleviate symptoms and enhance the endurance of activities. Stage 4 requires lung transplant  Bronchodilators Bronchodilator is the key medications to control the symptoms of COPD when symtpoms may not be controlled well Bronchodilators are prescribed on an as-needed or on a regular basis to prevent or reduce symptoms SOB may relate to env/activity, may not be necessary to use regularly The principal bronchodilator treatments are beta2-agonists, anticholinergics, * theophylline or combination therapy dosage shd be strictly under the prescription by medical officer The choice of treatment depends on each patient’s response in terms of symptom relief and side effects last for few hours, stabilise Long-acting inhaled bronchodilators are convenient and more effective for symptom relief than short-acting bronchodilators immediate relief, but not be able to stabilise the whole disease Long-acting inhaled bronchodilators reduce exacerbations and related hospitalizations Combining bronchodilators of different pharmacological classes may improve efficacy and decrease the risk of side effects compared to increasing the dose of a single bronchodilator Inhaled Corticosteroids Regular treatment with inhaled corticosteroids (ICS) improves symptoms, lung function and quality of life and reduces frequency of exacerbations for COPD patients with an FEV1 < 60% predicted Inhaled corticosteroid therapy is associated with an increased risk of pneumonia Withdrawal from treatment with inhaled corticosteroids may lead to exacerbations in some patients * Combined Formulation For Quick Relief For Prevention (β2 agonist + Anticholinergic) Bronchodilator + Corticosteroid To act as Quick relievers; rapid To achieve control of symptoms, onset, but short duration of less side-effects than using a action (4 – 6hr) higher dose of corticosteroids Combivent (Ventolin + Atrovent) controllers * Summary of Inhaled Medications for COPD Blue: short- acting Green: long- acting Red: corticosteriods Orientaldaily.on.cc/content/20241022 調查：依賴短效氣管舒張劑 增死亡風險 據統計，本港有超過33萬人患哮喘，不少患者發作時會使用短效氣管舒張劑（SABA）紓緩不適，但 若長期過度依賴恐不利控制病情。有研究發現，近六成受訪患者過度依賴短效氣管舒張劑，入院及死 亡風險更分別因而高達4倍及1.8倍，用量愈多死亡風險愈高。原文網址：調查：依賴短效氣管舒張劑 增死亡風險 | 東方日報 | 要聞港聞 https://orientaldaily.on.cc/content/news/odn-20241022- 1022_00176_063/ SABA無抗炎 反增哮喘發作 呼吸系統專科醫生盧浩然表示，控制哮喘藥物以吸入式藥物為主，可分為兩大類，即時紓緩性藥物可用作迅速擴張 支氣管，傳統處方多為短效支氣管舒張劑；長期預防性藥物的主要作用則為減少呼吸道炎症，以長遠控制病情，常 見選擇有吸入式類固醇（ICS）、結合ICS及長效支氣管舒張劑（LABA）的吸入式混合型藥物。雖然SABA起效作用迅 速，但並沒有抗炎作用，單獨使用無法處理氣管炎症，有機會增加哮喘發作機會，最終導致過度依賴，形成惡性循 環。所謂過度依賴SABA，即患者一年內需要使用3支或以上SABA，香港大學早前進行研究，共有17,782名12歲或以 上哮喘患者參與，發現本港哮喘患者每年平均獲處方5支SABA吸入器，有59.1%受訪患者出現過度依賴情況，約30% 患者更每年平均獲處方多於11支SABA吸入器，以長者情況最嚴重。研究亦發現，過度依賴SABA組別的入院及死亡風 險，比沒有過度依賴的組別分別高達2至4倍及1.2至1.8倍。全球哮喘倡議組織早年已針對哮喘治療策略更新治療指引， 建議哮喘患者不再單獨使用SABA治療，並建議應首選結合吸入式類固醇的混合性氣管舒張劑（ICS-formoterol）。香 港哮喘會亦作出3大建議，包括必須要跟從醫護人員指示用藥，切勿自行停藥或更改用藥劑量；其次，盡早了解吸入 器使用方法，以免誤用影響病情控制；以及使用哮喘日記簿記錄個人使用SABA次數。原文網址：調查：依賴短效氣 管舒張劑 增死亡風險 | 東方日報 | 要聞港聞 https://orientaldaily.on.cc/content/news/odn-20241022-1022_00176_063/ OT intervention for COPD LTOT Home Oxygen Therapy Definition: A low flow oxygen system for use by patients with chronic conditions at Low flow system; flow rates less than the patient’s inspiratory demand & not for supporting life in acute situations, e.g. nasal cannula pump into the lung High flow system; flow rates high enough to completely satisfy the patient’s inspiratory demand by entrainment of ambient air or by a high flow of gas, e.g. Venturi mask Use of Home O2 Therapy – LONG TERM Continuous Exhibit chronic hypoxaemia (PaO290% for dose titration on all ADL tasks. In general, the flow-rate may need to be increased by 1 L/min (or more) above the resting flow setting for exertional ADL tasks. Sleep Overnight oximetry is recommended to determine the best sleep oxygen flow setting. Routine increase of flow-rate by 1L/min above the daytime resting flow-rate is NOT recommended. With early signs Maintain original regime; increasing oxygen flow-rate automatically is NOT of AECOPD recommended flow-rate cannot be adjusted