Known Allergies: Shellfish. Symptoms: abdominal pain, nausea, diarrhea, or vomiting. congestion, trouble breathing, or wheezing.

Transcription

1 CSTAR CASE STUDIES: BLOCK B Asthma or COPD? Setting: Walk in clinic. Dan: I havi g that cough thi g agai HPI: Dan is a 49-year-old male teacher who reports having had episodes of cough with mucus production and SOB 1 to 3 times a year during the past 4 years. He can speak in full sentences, does not appear to be in acute respiratory distress and denies any fever. His cough wakes him up a few times a night, and he is becoming concerned that this is happening more frequently. Previously Dan has been treated with a variety of medications. Symptoms used to be seasonal (Late Summer and Fall), but now seem sporadic throughout the year. Dan thinks this is all due to old age. Known Allergies: Shellfish. Symptoms: abdominal pain, nausea, diarrhea, or vomiting. congestion, trouble breathing, or wheezing. Habits: He has smoked a pack a day for the past 10 years. Used to walk 3-4 times a week, but because of breathing difficulties now walks once a week with a friend. FHx: Sister has asthma. Grandfather (a smoker) died of emphysema at the age of 70. Physical Exam: Regular heart rate and rhythm. No fever (37C), blood pressure is in normal range. Decreased breath sounds with scattered, end-respiratory wheeze. Discussion Questions: What points to asthma, and what to COPD? What test could guide you to a Dx? What therapy would you recommend?

2 Discussion Q Answers: Differential for Asthma and COPD: As expected for asthma, Dan has nocturnal symptoms, a history of allergies and FHx of asthma. Dan also fits the age criteria for COPD, with late onset of symptoms, progressing symptoms that are now year-round, and modified lifestyle to accommodate reduced exercise tolerance. Smoking and coughing symptoms are not definitive for either disorder. TESTS: allergy testing or CXR, might be useful later but not for diagnosis itself. Order spirometry testing. Need to determine amount of reversibility of any airway flow obstruction pre and post bronchodilator. Spirometry measures how much air is inhaled, exhaled and how quickly one exhales. COPD = FEV1/FEV post bronchodilator < 0.7 MRC Dyspnea Scale Forced expiratory volume (FEV) measures how much air a person can exhale during a forced breath (FEV1 = air expelled in 1 sec). Forced vital capacity (FVC) is the total amount of air exhaled during the FEV test. The normal values for FEV1 vary from person to person. They re based on standards for an average healthy person of your age, race, height, and gender. Each person has their own predicted FEV1 value. TREATMENT: Core treatment is bronchodilators Shifts the flow-volume curve right, expiratory flow rates improve IC (inspiratory capacity) increases because a larger vol. of air can be inspired because peak flow has improved. Mild COPD: SABD (short acting bronchodilator) Moderate: LAAC/LABA (long-acting anticholinergics, beta-agonist) + SABD Severe: LAAC + ICS/LABA (inhaled corticosteroid/long-acting beta-agonist) + SABD Vaccination Status: People with COPD have inflamed and narrowed airways and damaged air sacs, which makes them more prone to developing lung infections

3 Extra Info: COPD: Largely caused by smoking, partially reversible airway obstruction, mortality has increased (#1 cause of rehospitalization) RISK FACTORS: childhood infections, asthma all increase susceptibility to COPD. Aging pop., socio-economic status, genes Symptoms: shortness of breath, chronic cough, sputum Exposure to risk factors: tobacco, occupation, indoor/outdoor pollution Pathophysiology: Flow limitation: EXPIRATORY airflow limited = HALLMARK of COPD. Small airways collapse and compromise ability to expel air, trapping air in lungs and hyper-inflating lungs -Because of EFL, alveolar emptying critically dependent on expiratory time: needs to be long enough of results in hyperinflation (breathing in before done breathing out) Note: EFL Expiratory Flow Limitation (when flow ceases to increase with increasing expiratory effort) -a decrease in lung elastic recoil pressure, airway tethering, increased airway resistance (mucus) all lead to dynamic compression of airways and EFL. Lung hyperinflation: PRINCIPLE CAUSE of dyspnea, physiological mechanism that links expiratory airflow to patient outcomes. Dyspnea: sense of increased effort to breath, heaviness, air hunger/gasping. Exacerbations: infections (so vaccines are a good idea) Approach: DIAGNOSIS (evaluation) SPIROMETRY required to establish diagnosis: FEV1/FEV post bronchodilator < 0.7. doesn t consider the impact on life quality though. MANAGEMENT: Goals of COPD management -prevent disease progression (stop smoking), -reduce freq. & severity of exacerbations, -alleviate symptoms, -improve health status, -reduce mortality Exacerbations of COPD: ACUTE exacerbation: sustained worsening of dyspnea, cough or sputum production in LESS THAN 48 HOURS I crease use of ai te a ce edicatio s a d/or supple e tatio ith additio al eds. MOST COMMON exacerbations: infections (80%), noninfectious (20%, noncompliance or environmental factors)

4 Asthma: syndrome characterized by AIRWAY INFLAMMATION, different phenotypes that vary with age. Complex interaction between genetic predisposition (this isn t inheritance) & environmental exposures CHARACTERISTICS: Variable expression clinically (wheezing), variable airway OBSTRUCTION, variable inflammation (can depend on allergies), remodeling, genetic multicomponent susceptibility. 3 KEY FACTORS of ASTHMA: it is a chronic inflammatory disorder associated with: 1. Reversible airway obstruction 2. Bronchial hyper- responsiveness: too twitchy inhale an allergen and airway constricts more than a normal person (too sensitive) 3. Airway inflammation SIGNS: Recurrent episodes of wheezing, coughing NIGHT TIME, cough/wheeze after EXERCISE, hypersensitive to allergens/pollutants, colds tend to go to chest and take 10+ days to clear (note: these symptoms are seen in other diseases) TRIGGERS: respiratory infections. **Rhinovirus in infancy in #1 trigger for asthma exacerbation, allergens, pollutants, medications, physical factors (exercise or cold air), physiological factors (obesity, stress, etc.) typically a predisposition PLUS early exposure to resp. infection starts asthma in kids. In adults will have a strong exposure to trigger it. DIAGNOSIS: -History and pattern of symptoms, measuring lung function (SPIROMETRY, PEAK FLOW), airway responsiveness, inflammatory status of airways (look at sputum) -Peak Flow: reflects larger airway patterns (not small), huge dip in night time flow. **Spirometry: mostly use this to measure (30% of physician diagnosed asthma is mistaken when not using this) Key Points: FEV1 and PEF decreased, FVC decreased or unchanged, FEV1/FVC ratio decreased In well controlled patients above stats can be normal Treatment: REVERSIBILITY: characteristic of most asthma, significant reversibility: Improvement in FEV1 of at least 12% AND at least 200ml within 30 minutes (must have both). Measure airway responsiveness (to see if patient has asthma): provocation test, constricts airways of someone with potential for asthma, keep administering allergen (until FEV falls 20%) Long term goal is to control/maintain symptoms also earl i ter e tio s to pre e t e posure to risk factors that sensitized the airway may help improve the control of asthma HIGH YIELD: What is considered to constitute acceptable control of asthma in Canada? Canadian Asthma Control Criteria: 1. Daytime symptoms <4 days/week 2. Night time symptoms <1 night/week 3. Normal physical activity

5 4. Mild, infrequent exacerbations 5. No absenteeism due to asthma 6. Fewer than 4 doses/week of SABA needed 7. FEV1 or PEF >85% of personal best or greater 8. Diurnal (daytime) variability in PEF less than 15%