Understanding The Respiratory System PDF

Understanding the Respiratory System Before we delve into the knowledge of asthma, it is crucial to understand how our respiratory system functions. Watch the following 11-minute video to gain a clear understanding of the respiratory system. https://youtu.be/7FhzSSQxM54 Now that you have a basic und...

Understanding the Respiratory System Before we delve into the knowledge of asthma, it is crucial to understand how our respiratory system functions. Watch the following 11-minute video to gain a clear understanding of the respiratory system. https://youtu.be/7FhzSSQxM54 Now that you have a basic understanding of the respiratory system, let's look into what asthma is. What is asthma: o Is a chronic lung condition caused by narrowing of the airways when they become inflamed. o Can be controlled but not cured. Once people develop asthma, they're likely to have it for life. Even if they don't have any symptoms - even if they feel just fine - asthma is still there and can flare up at any time. Asthma is characterised by: o Chronic airway hyperresponsiveness. o Intermittent airway narrowing due to bronchoconstriction, congestion or oedema of bronchial mucosa or mucus. o More likely to be diagnosed as ‘allergic asthma’ if person has history of allergies including atopic dermatitis (eczema) or allergic rhinitis (‘hay fever’) and family history of asthma and allergies. (AIHW, 2024) Symptoms of asthma: The symptoms of asthma are different for different people. Most people who have asthma have one or more of these symptoms: Coughing: Coughing from asthma is often worse at night, making it hard to sleep. Sometimes coughing brings up mucus. Wheezing: Wheezing is a whistling or squeaky sound when you breathe. Chest tightness: This can feel like something is squeezing or sitting on your chest. Shortness of breath: Some people say they can’t catch their breath, or they feel out of breath— like they can’t get enough air out of their lungs. Other conditions can cause these symptoms. But in asthma, the symptoms often follow a pattern: o They come and go over time or within the same day. o They start or get worse with viral infections, such as a cold. o They are triggered by exercise, allergies, cold air, or breathing too fast from laughing or crying. o They are worse at night or in the morning (WHO, 2024). o How asthma affects people's airways:  o The airways in people's lungs are very sensitive to substances such as tobacco smoke, dust, chemicals and pollen, or to getting a cold or the flu. These substances are called "asthma triggers" because people's immune systems overreact to them by triggering the release of cells and chemicals that cause asthma: o The inner linings of the airways to become more inflamed (swollen), leaving even less room in the airways for the air to move through. The muscles surrounding the airways to get bigger and tighten. This squeezes the airways and makes them smaller. (This is called bronchospasm.) Glands in the airways to produce lots of thick mucus, which further blocks the airways. o If asthma-related inflammation is not properly managed, repeated exposure to asthma triggers will exacerbate the inflammation, leading to worsening symptoms. (AIHW, 2024) What causes asthma? The exact causes for developing asthma are unknown and may be different from person to person. However, asthma can also occur when the body’s natural defenses against germs and sickness react strongly to a new substance in the lungs. Asthma usually starts during childhood when the body’s defense system is still taking shape. However, some people don’t show signs of asthma until adulthood — this is known as adult- onset asthma. Certain factors can affect how a person's lungs develop or how the body fights germs. Many factors may work together to cause people to develop asthma, such as: o Things in the environment (called allergens) that affected you as a baby or young child, including cigarette smoke or certain germs o Viral infections that affect breathing o Family history, such as a parent who has asthma (especially your mother) The following may also raise the risk of developing asthma. What causes asthma? The following may also raise the risk of developing asthma: o Allergies: Asthma is usually a type of allergic reaction. People who have asthma often have other types of allergies, such as food or pollen allergies. o Obesity: Being overweight can raise the risk of developing asthma or make your asthma symptoms worse. o Race or ethnicity: Puerto Rican people and Black or African American people have a higher risk of developing asthma than people of other racial or ethnic groups. Black or African American and Hispanic children are more likely than non-Hispanic White children to die from asthma. o Sex: More boys than girls have asthma as children. In adults, asthma is more common among women. o Occupational hazards: Breathing in chemicals or industrial dust in the workplace can raise your risk of developing asthma.  o Climate change: Air pollution and changing weather patterns contribute to asthma onset and exposure to allergens. (National Heart, Lung, and Blood Institution, 2024) Asthma triggersHow is Asthma Classified? Asthma is classified into four levels based upon frequency of symptoms and objective measures, such as peak flow measurementsLinks to an external site. and/or spirometry results. These categories are mild intermittent; mild persistent; moderate persistent; and severe persistent. Physicians assess the severity and control of patients' asthma by evaluating the frequency of symptoms and conducting lung function tests. It is crucial to recognise that an individual's asthma symptoms can transition between different severity categories over time. Mild Intermittent Asthma Symptoms occur less than twice a week, and nighttime symptoms occur less than two times per month. Lung function tests are 80% or more above predicted values. Predictions are often made on the basis of age, sex, and height. No medications are needed for long-term control. Mild Persistent Asthma Symptoms occur three to six times per week. Lung function tests are 80% or more above predicted values. Nighttime symptoms occur three to four times a month. Moderate Persistent Asthma Symptoms occur daily. Nocturnal symptoms occur 5 or more times per month. Asthma symptoms affect activity, occur more than two times per week, and may last for days. There is a reduction in lung function, with a lung function test range above 60% but below 80% of normal values. Severe Persistent Asthma Symptoms occur continuously, with frequent nighttime asthmaLinks to an external site.. Activities are limited. Lung function is decreased to less than 60% of predicted values (National Heart, Lung, and Blood Institution, 2024). Asthma triggers are things that set off or make asthma symptoms worse. Common triggers include: o Indoor allergens, such as dust mites, mold, and pet dander or fur. o Outdoor allergens, such as pollens and mold. o Emotional stress. o Physical activity, although with treatment you or your child should still be able to stay active.  o Infections, such as colds, the flu, or COVID-19. o Certain medicines, such as aspirin, which may cause serious breathing problems in people with asthma that is difficult to treat. o Poor air quality or very cold air. (National Heart, Lung, and Blood Institution, 2024) o What are the different types of asthma? o Asthma may also be classified by healthcare professionals into various types based on their causes or triggers. o Allergic Asthma: Allergic asthma is triggered by allergens such as pet dander, mold, dust mites, and pollen. o Eosinophilic Asthma: Eosinophilic asthma is characterized by high levels of eosinophils, a type of white blood cell, in the airways. This category includes nearly 70% of severe asthma cases. o Exercise-Induced Asthma: Exercise-induced asthma occurs when the airways constrict, leading to airflow obstruction during or after physical activity. Cold, dry air is a common trigger for this type of asthma. o Cough Variant Asthma: Cough variant asthma is a form of asthma where a chronic, recurring cough is the primary symptom. Individuals with this type of asthma may experience other symptoms such as wheezing and shortness of breath, although these occur less frequently. o Nighttime (Nocturnal) Asthma: Nighttime asthma symptoms occur during sleep, potentially due to hormonal changes. Approximately 30 to 70% of individuals with asthma report experiencing nighttime symptoms at least once a month. o Occupational (Work-Related) Asthma: Occupational asthma is caused by inhaling allergens, chemicals, and irritants in the workplace. (American Lung Association, 2022) What Is Childhood Asthma? Childhood asthma is the same lung disease that adults get, but kids often have different symptoms. Doctors may also call this pediatric asthma. Signs and Symptoms of Childhood Asthma During an asthma attack in children, the bronchial tubes, which transport air to the lungs, become inflamed and produce excess mucus. This inflammation and mucus production constrict the airways, resulting in breathing difficulties. The following signs and symptoms are commonly observed: A cough that doesn’t go away. Coughing spells that happen often, especially during play or exercise, at night, in cold air, or while laughing or crying (young kids may say that they "cough all the time"). A cough that gets worse after a viral infection, such as a cold or the flu. Less energy during play and stopping to catch their breath during activities. Avoiding sports or social activities. Trouble sleeping because of coughing or breathing problems. Rapid breathing.  Chest tightness or pain (young kids may say their chest "hurts" or "feels funny"). Wheezing, a whistling sound when breathing in or out. Seesaw motions in their chest (retractions). Shortness of breath. Tight neck and chest muscles. Feeling weak or tired. Trouble eating or grunting while eating (in infants). Childhood Asthma Risk Factors o Genetic Risk Factors. o Environmental Risk Factors: I. Maternal Tobacco Smoking: Increases the risk of childhood asthma. II. Maternal Diet: Higher intake of vitamin E, zinc, and polyunsaturated fatty acids during pregnancy is protective against childhood asthma, whereas high sugar intake is associated with increased risk. III. Other Perinatal Factors: Neonatal jaundice, maternal preeclampsia, and cesarean section delivery are associated with higher risk of childhood asthma development. o Natal Risk Factors: I. Chronic Lung Disease of Prematurity: Increases the risk of asthma development in children. II. Extreme Preterm Birth: Associated with an increased risk of asthma into young adulthood. III. Cesarean Section Delivery and Low Birth Weight: Linked with asthma diagnosis in mid-childhood, with symptoms potentially persisting into adult life. o Gender: ▪ Boys are more likely to develop childhood asthma than girls until puberty, possibly due to smaller airway size in boys, which predisposes them to worsened airway reactivity. o Family History: ▪ Both maternal and paternal histories of asthma are linked to an increased risk of asthma in offspring, with maternal history showing a stronger association. o Medical History: ▪ Atopy: The presence of IgE antibodies to specific allergens is strongly associated with childhood asthma. The “atopic march” often begins with atopic dermatitis in infancy, progressing to allergic rhinitis and then asthma.  ▪ Indoor Allergen Sensitization: Sensitization to house dust mite, alternaria mold, and cockroach allergens increases asthma risk. Early life exposure to cat and dog allergens has shown mixed results. o Medication Exposure: ▪ Exposure to antibiotics and antipyretics in infancy has been associated with an increased risk of developing childhood asthma, though the data is conflicting and may be influenced by uncontrolled confounding factors. Further studies are needed to clarify these associations. (Trivedi & Denton, 2019) What Is Adult-onset Asthma? Many people are first diagnosed with asthma in childhood, but it can present at any age. Adult- onset asthma is typically defined as asthma that begins any time after the age of 20 (Burdon, 2015). Among those who may be more likely to get adult-onset asthma are: Women who are having hormonal changes, such as those who are pregnant or who are experiencing menopause. Women who take estrogen following menopause for 10 years or longer. People who have just had certain viruses or illnesses, such as a cold or flu. People with allergies, especially to cats. People who have GERD, a type of chronic heartburn with reflux. People who are exposed to environmental irritants, such as tobacco smoke, mold, dust, feather beds, or perfume. Signs and Symptoms of Adult-onset Asthma Asthma causes inflammation and narrowing in the airways. Narrowed airways cause chest tightness and difficulty breathing. Symptoms of adult-onset asthma include: o wheezing. o coughing. o chest pain. o increased mucus secretion in the airways. o tightness or pressure in the chest. o shortness of breath after physical activity. o difficulty sleeping. o delayed recovery from a respiratory infection, such as the flu or a cold. Adult-onset Asthma Risk factors o Genetic Predisposition  ▪ The role of genetic predisposition in adult-onset asthma is less clear compared to childhood-onset asthma. ▪ A family history of asthma is often lacking in adult-onset cases. o Environmental and Occupational Factors ▪ Workplace Exposure: Occupational asthma is the most common type of adult- onset asthma in industrialised countries, comprising 9–15% of cases. It includes sensitiser-induced asthma and irritant-induced asthma (e.g., reactive airway syndrome). ▪ Environmental Pollutants: Active and passive cigarette smoking is a significant risk factor for adult-onset asthma. Persistent exposure to airborne allergens and cigarette smoke can have additive or synergistic effects. o Hormonal Influences ▪ Female Sex Hormones: Adult-onset asthma is more common in females, particularly during reproductive years. Hormonal changes related to menstruation, pregnancy, and menopause can influence asthma onset. ▪ Hormone Replacement Therapy: In post-menopausal females, hormone replacement therapy is associated with an increased risk of asthma onset. o Upper Airway Diseases ▪ Rhinitis: A well-recognised risk factor for adult-onset asthma. ▪ Chronic Rhinosinusitis and Nasal Polyposis: Positively associated with adult- onset asthma, with underlying mechanisms still being researched. o Medication and Drug Exposure ▪ Aspirin: Long-term intake of low-dose aspirin may reduce the risk of developing asthma in healthy individuals. ▪ Paracetamol: Use is associated with increased risk of developing asthma, potentially due to glutathione depletion and increased oxidative stress. o Respiratory Infections ▪ Acute lower respiratory infections are strongly linked to the risk of developing adult-onset asthma. Early exposures to common infections in childhood may decrease asthma risk later in life. o Obesity  ▪ Obesity significantly increases the risk of asthma onset in adults. The mechanisms include increased adipokines, mechanical factors affecting lung function, and the influence of obesity-related conditions like sleep-disordered breathing and gastro-esophageal reflux disease. o Stressful Life Events ▪ High levels of stress are associated with a two- to three-fold higher risk of self- reported asthma incidence. Stressful events include family illness, marital problems, and work-related stress, which can modulate biological pathways and contribute to asthma onset. (de Nijs, Venekamp, & Bel, 2013) Key Differences Between Childhood and Adult-onset Asthma: o Gender Prevalence: Childhood asthma is more common in boys, while adult asthma is more common in women. o Remission Rates: Childhood asthma often goes into remission, whereas adult asthma rarely does o Disease Stability: Adult asthma is generally less stable, with more relapses and less quiescent periods compared to childhood asthma. o Severity Indicators: Different factors are associated with asthma severity in children and adults, reflecting the complexity and variability of the condition across the life course. o Lung Function Decline: Forced expiratory volume (FEV1) tends to decrease in adults after middle age due to changes in muscles and stiffening of chest walls. This decreased lung function may cause doctors to miss the diagnosis of adult-onset asthma. (Trivedi & Denton, 2019) Childhood Asthma: Severity Factors: o o Duration of Symptoms: Longer symptom duration is linked to increased severity. o Medication Use: The need for medication often indicates more severe asthma. o Lung Function: Poor lung function is associated with more severe asthma. o Socioeconomic Status: Low socioeconomic status is a risk factor for severe asthma. o Racial/Ethnic Minorities: Minority groups may experience more severe asthma. o Neutrophilic Phenotype: A specific inflammatory pattern (neutrophilia) is linked to severity. (Trivedi & Denton, 2019) Adult-onset Asthma: Severity Factors:  o Increased IgE: Higher levels of IgE, an antibody related to allergic reactions, are associated with severe asthma. o Elevated FeNO: Higher levels of fractional exhaled nitric oxide (FeNO) indicate inflammation and severity. o Eosinophilia: An increased number of eosinophils (a type of white blood cell) is linked to more severe asthma. o Obesity and Smoking: Both are significant risk factors for severe asthma. o Socioeconomic Status: Low socioeconomic status remains a risk factor in adults (Trivedi & Denton, 2019) How common is asthma? Around 2.8 million (11%) people in Australia were estimated to be living with asthma, according to self-reported data in the 2022 Australian Bureau of Statistics (ABS) National Health Survey (NHS) (Australian Bureau of Statistics [ABS], 2023). In 2022, the prevalence of asthma was (Figure 1): higher for boys compared with girls aged 0–14 (10% and 6.2%, respectively) higher for females compared with males over the age of 15 (ABS, 2023). This change in prevalence for males and females over the age of 15 is likely to be due to a complex interaction between changing airway size and hormonal changes that occur during adolescent development, as well as differences in environmental exposures (Dharmage et al. 2019). After adjusting for different population age structures over time, the prevalence of asthma has remained relatively stable, at 12% in 2001 and 11% in 2022 (ABS, 2023). Based on the 2022 NHS, there was little difference in the prevalence of asthma by remoteness area or level of disadvantage (also known as socioeconomic area) (ABS, 2023). Prevalence in Aboriginal and Torres Strait Islander (First Nations) people The Australian Institute of Health and Welfare (AIHW) uses ‘First Nations people’ to refer to Aboriginal and/or Torres Strait Islander people in this report. In 2018–19, around 128,000 (16%) First Nations people were estimated to be living with asthma, based on the National Aboriginal and Torres Strait Islander Health survey (NATSIHS) (Figure 2), down from 18% in 2012–13 (ABS, 2019). How many deaths were associated with asthma? Asthma was recorded as an underlying cause of death for 467 deaths or 1.8 deaths per 100,000 population in Australia in 2022. This represented 0.2% of all deaths and 3.1% of all respiratory deaths in 2022. Asthma was more likely to be recorded as an associated cause of death and was recorded as such for an additional 2,005 deaths, resulting in a total of 2,472 deaths due to, or associated with, asthma. This represented 1.3% of all deaths and 4.5% of respiratory deaths. Variation by age and sex In 2022, asthma mortality rates (as the underlying cause of death):  increased with increasing age and were highest for people aged 85 and over (39 per 100,000 population) were higher for females compared with males for most age groups. Differences by sex were more pronounced with age (with females aged 85 and over having the highest mortality rate, 46 per 100,000 population, compared with males of the same age, 27 per 100,000 population). Variation between population groups In 2022, after adjusting for age differences, mortality rates for asthma (as the underlying cause of death) changed little by remoteness or level of disadvantage (also known as socioeconomic area). Rates were: 1.5 deaths per 100,000 population for people living in Outer regional areas and 1.3 per 100,000 population for those living in Major cities 2.0 per 100,000 population for people living in areas of most disadvantage (lowest socioeconomic areas), and 1.1 per 100,000 population for those living in the least disadvantaged areas (highest socioeconomic areas). Impact of asthma Asthma has varying degrees of impact on the physical, psychological, and social wellbeing of people living with the condition, depending on disease severity and their level of control. People with asthma are more likely to report poor quality of life, especially those with severe asthma (Kharaba et al. 2020). Measures of impact presented in this section include burden of disease, health expenditure and mortality data. Burden of disease In 2023, asthma accounted for 2.5% of total disease burden (also known as disability adjusted life years or DALY), 4.4% of non-fatal burden (also known as ‘years lived with disability’ or YLD) and 0.3% of fatal burden (also known as years of life lost, or YLL) (Figure 3). Within the respiratory disease group, asthma accounted for: 35% of total burden (DALY) 52% of non-fatal burden (YLD) 5.4% of fatal burden (YLL) (AIHW 2023b). Variation by age and sex In 2023: the overall rate of burden from asthma was 1.2 times as high for females compared with males (5.8 and 4.9 DALY per 1,000 population, respectively) asthma was the leading cause of burden for children aged 1–4 and 5–9 years (11%, and 13% of total burden (DALY), respectively). Variation between population groups In 2018, after adjusting for age differences, the rate of burden from asthma was highest for people living in:  Remote and very remote areas and lowest for people living in Major cities (7.3 and 5.0 DALY per 1,000 population, respectively) areas of most disadvantage (lowest socioeconomic areas) and lowest for people living in the least disadvantaged areas (highest socioeconomic areas) (6.9 and 3.7 DALY per 1,000 population, respectively) (AIHW, 2021). Comorbidities of asthma Some people living with asthma also live with other long-term conditions, known as ‘comorbidity’. For people with asthma, living with a comorbid chronic condition can have implications for their health outcomes, quality of life and treatment choices. According to the NHS, in 2022, an estimated 1.8 million (65%) people who were living with asthma also had one or more other chronic conditions – the top 3 comorbidities were mental and behavioural conditions (41%), back problems (25%) and arthritis (23%) (NHS 2023). Emergency department presentations for asthma Data from the National Non-Admitted Patient Emergency Department Care Database (NAPEDC) show that in 2021–22: there were 59,200 emergency department (ED) presentations for asthma, about 240 presentations per 100,000 population ED presentation rates were higher for females compared with males overall (260 and 225 per 100,000 population, respectively) boys aged 0–14 were 1.6 times as likely as girls of the same age to present to the ED for asthma. Between 2018–19 and 2021–22, ED presentation rates decreased from 300 to 240 per 100,000 population and were higher for females compared with males. In 2021–22, asthma ED presentations rates were around twice as high for: people living in Remote areas compared with people living in Major cities (420 and 215 per 100,000 population, respectively) people living in areas of most disadvantage (lowest socioeconomic areas) compared with people living in the least disadvantaged areas (highest socioeconomic areas) (320 and 160 per 100,000 population). Like asthma hospitalisations, asthma ED presentations can also be impacted by seasonal variation. However, differences observed between 2019 and 2020 are more likely to be due to the 2019–20 bushfire season and the COVID-19 pandemic. In 2020, ED presentation rates decreased significantly during the nationwide lockdown from March and increased again from May. Rates for most of 2020 were lower than observed in 2019, likely due to the impact of health protection measures implemented for the pandemic. Health system expenditure In 2020–21, an estimated $851.7 millions of expenditure in the Australian health system was attributed to asthma, representing 0.6% of total health expenditure and 19% of expenditure of all respiratory conditions (AIHW, 2023). In 2020–21, asthma accounted for:  2.6% ($450.6 million) of all PBS expenditure – ranking 11th of all diseases/conditions. 1.4 % ($152.0 million) of all GP expenditure. What is asthma attack? Asthma attacks, or flare-ups, happen when swelling or tightening narrows the airways, making it harder to breathe. During an asthma attack, symptoms get much worse. Attacks can come on quickly or gradually and may be life- threatening. People with asthma that is difficult to treat may get asthma attacks more often. Who is 'at risk'? People who have Frequent visits to the GP or emergency department with acute asthma or hospital admission in past 12 months. Previous life-threatening attack or admission to an intensive care unit. No preventive medications/excessive reliance on inhaled bronchodilators. Patient denial. Poor adherence/insight. Failure to perceive asthma symptoms. Immediate hypersensitivity to foods, especially nuts. Asthma triggered by aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs). Poor access to health services. The following video (0.51 mins) shows what happens to the body during an asthma attack. Initial management of life-threatening acute asthma in adults and children What is Thunderstorm Asthma? Thunderstorm asthma refers to episodes of asthma symptoms that occur when high pollen levels combine with a thunderstorm. These episodes require very specific weather conditions and are rare. Only a few thunderstorms that occur during times of high pollen levels have a significant health impact. When these conditions happen near highly populated areas, many people can be affected simultaneously. Watch the following 2-minute video to get an understanding of what thunderstorm asthma is. Occurrence in NSW Thunderstorm asthma events have occurred in some areas of NSW, such as the region surrounding Wagga Wagga. However, the Sydney Metropolitan Region has not experienced a significant thunderstorm asthma event. Symptoms of Thunderstorm Asthma The symptoms associated with thunderstorm asthma can escalate quickly and may become life- threatening. They include:  Wheeze Chest tightness Difficulty breathing Cough Causes of Thunderstorm Asthma The exact cause of thunderstorm asthma is not fully understood. Exposure to high concentrations of very small pollen fragments appears to be an important factor. During a thunderstorm, moisture in the air swells pollen grains, causing them to burst and release tiny fragments. Airflows in some thunderstorms can concentrate these fragments at ground level, where they may be inhaled and trigger asthma symptoms. In NSW, high levels of rye grass pollen are associated with thunderstorm asthma in some areas. Who is at Risk? People at risk of thunderstorm asthma include: Individuals with asthma Individuals with undiagnosed asthma Individuals with hay fever (allergic rhinitis) Individuals who experience wheezing and sneezing during spring When are People Most at Risk? In NSW, the period from October to November is a time of higher risk for thunderstorm asthma. Being outside when pollen levels are high and thunderstorms are in the area increases the risk of exposure, potentially leading to thunderstorm asthma. Diagnosis of asthma Diagnosis - Adults: No single reliable test ('gold standard') and no standardised diagnostic criteria for asthma. Asthma cannot be diagnosed with a single test; instead, a combination of assessments is used to confirm the condition. The diagnosis is based on a detailed medical history and physical examination, focusing on the chest and airways Lung Function Tests: Lung function tests, also known as pulmonary function tests, measure how well a patient can inhale (breathe in) and exhale (breathe out) air from their lungs. These tests are often conducted before and after the administration of a bronchodilator, a medication that opens the airways. If there is significant improvement in lung function after using a bronchodilator, it is indicative of asthma. Common lung function tests used to assess airways include: 1. Spirometry: Spirometry is the best lung function test for diagnosing asthma and for measuring lung function when assessing asthma control. This test measures the volume of air a patient breathes in and out and the speed at which they exhale. It helps to evaluate the overall lung capacity and airflow. Spirometry can: 1) detect airflow limitation; 2) measure the degree of airflow limitation compared with predicted normal airflow (or with personal best); 3) demonstrate whether airflow limitation is reversible. This test is suitable for most adults and kids aged six and older. Common lung function tests used to assess airways also include: 2. Peak Expiratory Flow (PEF) Tests: PEF tests measure the speed at which a person can exhale air using maximum effort. These tests can be performed during spirometry or with a small handheld device. PEF tests provide valuable information about the patient's lung function and airway capacity. 3. Bronchodilator Responsiveness Tests: These tests assess how much improvement in airflow a patient experiences after inhaling a fast-acting bronchodilator. This medication relaxes the muscles around the airways, helping to open them up. The test compares spirometry or PEF results before and after administering the bronchodilator. A significant improvement in airflow indicates a positive response to the bronchodilator, which is a strong indicator of asthma. 4. FeNO Test (Exhaled Nitric Oxide): This test assesses the level of inflammation in the airways by measuring the amount of nitric oxide in the exhaled breath. 5. Bronchial Provocation or “Trigger” Tests: These tests determine if the lungs are sensitive to specific irritants or triggers. They help in identifying substances that may provoke asthma symptoms. Challenge Tests: Challenge tests, also known as bronchial provocation tests, evaluate the sensitivity of the airways. These tests measure the speed of exhalation before and after exposure to a challenge agent. Challenge agents are substances or activities that may induce airway constriction in sensitive individuals, such as: o Inhaled medicines like methacholine, mannitol, or histamine o Allergens or irritants that do not affect individuals without asthma o Exercise, which can cool and dry the airways o Hyperventilation, involving rapid, shallow breathing Other Diagnostic Tests: Healthcare providers may conduct additional tests to diagnose asthma and assess the risk of asthma flare-ups. These tests can also predict the patient's response to medications. o Allergy Tests: Consultation with an allergy specialist may be beneficial, as most individuals with asthma have allergies that can trigger or exacerbate their condition. Allergy tests can help identify specific allergens that need to be managed to control asthma symptoms. o Blood Tests: Blood tests are used to evaluate the immune system by checking the levels of certain white blood cells and antibodies. Specifically, the tests measure eosinophils and immunoglobulin E (IgE). Elevated levels of these markers may indicate severe asthma, providing additional information for diagnosis and treatment planning. Diagnosis - Children:  Difficult to diagnose in children under 5 years as: Wheezing and cough are common in children, particularly under 3 years – ‘small airway syndrome’. Many children who respond to bronchodilator treatment do not go on to develop asthma. Infants (age 0 -12 months): asthma should not be diagnosed. Preschool (age 1 -5years): Difficult to diagnose in this age group, because: o Episodic respiratory symptoms such as wheezing, and cough is very common in young children. o Spirometry is usually hard to perform in children. Many children who respond to bronchodilator treatment do not go on to develop asthma Medicines Medications are a crucial component of asthma management. The primary goals of asthma medication are to control symptoms, prevent asthma attacks, and improve lung function. While there is no cure for asthma, proper medication and support can help individuals live symptom-free. Asthma medications are generally categorised into three main groups: 1. Preventers: These medications treat asthma to help maintain symptom-free periods. They include preventers, combination preventers, and non-steroidal preventers. 2. Relievers: These medications address symptoms triggered by asthma. They encompass relievers and dual-purpose relievers. 3. Add-On Medicines: These helps manage persistent asthma symptoms or severe asthma. They include long-acting bronchodilators, oral corticosteroids, and monoclonal antibodies (Asthma Australia, 2024). What are we looking for as nurses? Chest discomfort. Dyspnea. Chest tightness. Cough. Blue lips and fingers. Tachypnea, tachycardia. Tripod position. Wheezing. The following two-minute video provides an auditory demonstration of the lung sounds of asthma. Nursing management of asthma Check oxygen status Listen to lungs  Assess for respiratory distress Position patient upright Administer medications as prescribed When To Seek Help Respiratory distress. No air entry in lungs during auscultation. Low oxygen saturation. Patient cyanotic. (Hashmi, Cataletto & Hoover, 2024) What is evidence-based practice? Evidence-Based Practice (EBP) is an interdisciplinary approach to patient care and treatment. Originating in medicine as evidence-based medicine (EBM), it has since expanded to fields such as nursing, psychology, education, and information services. The currently accepted definition of EBP is "the integration of the best available research evidence with clinical expertise and the patient's unique values and circumstances". The purpose of EBP is to assist in clinical decision-making (Hoffman, 2017). Whether consciously or not, every time a decision is made—be it personal or clinical—alternatives are identified, information is collected, and the quality of this information is assessed and integrated to make an informed choice. An evidence-based practice approach acknowledges that the most robust clinical decisions are made by integrating information from three key sources: 1. Clinical expertise and experience – This encompasses your knowledge, skills, and experience, as well as the context and resources available to you. 2. Patients’ values, preferences, and circumstances – This includes the values and preferences of patients and their families, as well as financial considerations. 3. Best scientific evidence – This involves utilizing published literature and research, including systematic reviews, primary research (e.g., randomised controlled trials, cohort studies), and clinical practice guidelines. Why is this important for nurses? According to the Registered Nurse Standards for Practice, "Registered nurse practice is person- centred and evidence-based, encompassing preventative, curative, formative, supportive, restorative, and palliative elements." Standard 1 states that registered nurses need to "access, analyse, and utilise the best available evidence, including research findings, to ensure safe and high-quality practice" (Nursing and Midwifery Board of Australia, 2016). The 5 Steps of Evidence-Based Practice The five steps of EBP offer a structured approach to navigating the vast amount of research literature available and finding the best evidence to inform your practice. These steps are as follows: 1. Ask - Formulate a well-defined and answerable clinical question. 2. Acquire - Develop the knowledge and skills to find relevant evidence. 3. Appraise - Assess the trustworthiness and believability of the evidence.  4. Apply - Interpret the findings and their significance to apply them in practice. 5. Assess - Evaluate your effectiveness and efficiency in performing steps 1-4. (Clinical Information Access Portal, 2016) Quantitative research Quantitative research, with its focus on numerical data and statistical analysis, is one of the main research types that provides essential evidence for evidence-based practice in nursing, offering reliable data to guide clinical decisions and enhance patient care. Watch the following 8-minute video to get a basic understanding of what quantitative research is. Types of research in Quantitative Research There are four main types of Quantitative research: Descriptive, Correlational, Causal- Comparative/Quasi-Experimental, and Experimental Research (Barroga et al., 2023). Descriptive Objective: To examine characteristics of a particular situation or group. Approach: Provides systematic information about a phenomenon. Researchers often do not begin with a hypothesis but may develop one after data collection. The analysis and synthesis of data test the hypothesis. Method: Requires careful selection of the units studied and precise measurement of variables. Cross-Sectional Studies o Definition: Studies that analyse data from a population, or a representative subset, at a specific point in time. o Purpose: To describe the prevalence of an outcome or to identify the relationships between variables at a single point in time. o Example: Surveying patients to assess the prevalence of hypertension in a community. Correlational Objective: To determine the extent of a relationship between two or more variables using statistical data. Approach: Seeks and interprets relationships between variables. Recognises trends and patterns in data without proving cause and effect. Method: Observational research that interprets data, relationships, and variable distributions without establishing causality. Cohort Studies o Definition: Observational studies where subjects are followed over time to observe the occurrence of outcomes. o Purpose: To identify relationships and risk factors associated with certain health outcomes. o Example: Following a group of smokers and non-smokers over several years to compare the incidence of lung cancer. Case-Control Studies o Definition: Observational studies that compare individuals with a specific condition (cases) to those without the condition (controls). o Purpose: To identify factors that may contribute to the condition by comparing the exposure history of both groups. o Example: Comparing patients with a history of myocardial infarction to those without to identify lifestyle factors that may contribute to heart attacks. Casual comparative Quasi-Experimental Studies o Definition: Studies that aim to evaluate the cause-effect relationship between an intervention and an outcome without random assignment. o Purpose: To determine the effectiveness of an intervention when randomization is not feasible. o Example: Evaluating the impact of a new nursing protocol on patient recovery times in different hospital units where random assignment is not possible. o Quasi-Experimental Studies o Definition: Studies that aim to evaluate the cause-effect relationship between an intervention and an outcome without random assignment. o Purpose: To determine the effectiveness of an intervention when randomization is not feasible. o Example: Evaluating the impact of a new nursing protocol on patient recovery times in different hospital units where random assignment is not possible. o Experimental Objective: To establish cause-effect relationships among variables. Approach: Uses the scientific method to identify and control variables, except one (independent variable), to determine its effects on the dependent variables. Subjects are randomly assigned to each variable. Method: Often considered a laboratory study but can occur in various settings. Effort is made to impose control over all variables except the one being studied. Randomised Controlled Trials (RCTs) o Definition: Experimental studies where participants are randomly assigned to either an intervention group or a control group. o Purpose: To determine the effectiveness of an intervention by minimising bias and establishing causality. o Example: Testing the effectiveness of a new drug for asthma by randomly assigning patients to receive either the drug or a placebo. Controlled Clinical Trials o Definition: Similar to RCTs but without random assignment. Groups are assigned based on specific criteria. o Purpose: To assess the efficacy of treatments or interventions under controlled conditions. o Example: Comparing outcomes of patients receiving standard care versus an alternative therapy in clinical settings where randomisation is not applied. Type of research Quantitative Research Research that focuses on quantifying data and using statistical methods to identify patterns, relationships, and generalisations. Data type: Numeric data Example: Surveys with Likert scales, statistical data from experiments. Qualitative Research Research that seeks to understand phenomena through detailed descriptions and interpretations of non-numeric data. Data type: Non-numeric data Example: Interviews, focus groups, and observational notes P (Population) – Who are the people or patients of interest? I (Intervention) – What treatment, prevention or other health care intervention are we interested in knowing about? C (Comparison) – The alternative intervention or treatment You use this to check whether your intervention is working. This can be no treatment. O (Outcome) – What is the desired outcome? What are you hoping to achieve? RCT People who are interested to participate in the study are screened to make sure they are appropriate. 2. Participants are randomised into an intervention group or comparison/control group. 3. Intervention group receives new intervention/treatment and control group receives usual care or no intervention at all. 4. Participants in both intervention and control groups are followed up for a certain period of time. 5. Participants in intervention and control group are compared in regard with the study outcomes. Better results in intervention group shows the effectiveness of the new intervention/treatment. Screening & sampling Randomization Intervention Follow- up Outcome Assessment 18 COHORT An observational study A defined group of people (cohort) is followed over time Prospective cohort study examines the occurrence of an outcome of interest in participants wo are exposed to a particular risk. Retrospective cohort study examines the exposures and outcomes that have already occurred. Usually includes a control group to allow for the control of the effects of con-founding factors. 19 CASE CONTROL Compares people with a specific disease or outcome of interest (cases) to people from the same population without that disease or outcome (control) Looks for associations between the outcome and exposure to risk factors Usually retrospective CROSS SECTIONAL A cross-sectional study is an observational study that analyses data from a population at a specific point in time. Key Characteristics: Observes a snapshot of a specific moment Measures prevalence, not incidence Useful for assessing the burden of diseases and health conditions Case studies: A case study is an in-depth examination of a certain phenomena in an individual or in small number of individuals. Case studies examine complex phenomena in the natural setting to increase understanding of them. Case reports: A detailed report of the diagnosis, treatment, and follow-up of an individual patient. Provides a comprehensive account of the patient's condition and the clinical management. Highlights unique or rare conditions, unexpected responses to treatment, or novel treatment approaches. HIERARCHY OF EVIDENCE PAEDIATRIC ASTHMA RISK FACTORS History of poorly controlled asthma  Previous ICU admission for asthma  Re-presentation after discharge from hospital  Recurrent admissions  Poor compliance with preventer medication eg. Flixotide  Overuse of reliever medication eg. Short Acting Beta Agonists such as Ventolin  Nocturnal symptoms  Two or more courses of oral steroids eg. Prednisoslone or one or more asthma hospitalisations in the last 12 months  Social factors and vulnerabilities eg. poor health literacy NSW Health (2023) Assessment Airway- Patency, audible wheeze may be present, cough, ability to speak in sentences/cry  Breathing- Resp rate, work of breathing/use of accessory muscles, O2 saturations, supplementary O2 requirement, air entry, adventitious breath sounds  Circulation- Heart rate, BP, colour, cap refill  Disability- GCS, pain  Exposure- Temperature  Fluids- Hydration status, intake/output  Glucose- BGL  Holistic/social- Parent/carer Discharge Asthma education  Asthma Action plan  Ventolin weaned to 3 hourly or less  Follow up with GP or High Risk Asthma Clinic Salbutamol What is Salbutamol? What does it do? What are side effects? Prednisolone What is Prednisolone? What does it do? What are the side effects? 18 Group work: asthma medications Symptom control: achieve good control of symptoms maintain normal activity levels Risk reduction- minimise: risk of lung-attacks fixed airflow limitation medication adverse effects 21 Goals of asthma management? Medications Self-Monitoring Education and Skills Knowledge, inhaler technique, adherence, written asthma action plans Avoiding triggers Regular review (every 6 months) Symptoms often deteriorate before PEF, therefore symptom monitoring can be more reliable than PEF 23 Self-monitoring Symptoms Facilitates early detection and treatment of an asthma exacerbation Personalised instructions for self-management of deteriorating asthma Example of asthma action plan When to increase treatment 2. How to increase treatment 3. How long to stay on increased treatment 4. When to seek urgent medical assessment 5. Patient engagement and acceptance