Myths and Facts about Asthma Diagnosis and Treatment

Cough is a crucial diagnostic feature in asthma, especially if it occurs at night. However, it is not the only symptom, and other factors must be considered to reach a diagnosis. While asthma often presents in childhood, it can also appear later in life, and some patients may experience a recurrence of symptoms after a period of remission. The 15% reversibility test is useful but not essential for diagnosis, and there is no single test that can definitively diagnose asthma. Inhaled corticosteroids are not bronchodilators and do not have an immediate effect, but they are essential for managing inflammation and preventing irreversible airway damage. Finally, family history is a crucial factor in asthma diagnosis, as there is a strong genetic component to the disease.

Symptoms and Signs of Pulmonary Embolism

Pulmonary embolism (PE) is a serious condition that can be life-threatening. It is important to recognize the symptoms and signs of PE to ensure prompt diagnosis and treatment. Here are some of the common symptoms and signs of PE:

Dyspnoea: This is the most common symptom of PE, present in about 75% of patients. Dyspnoea can occur at rest or on exertion.

Tachypnoea: This is defined as a respiratory rate of more than 20 breaths per minute and is present in about 55% of patients with PE.

Tachycardia: This is present in about 25% of cases of PE. It is important to note that a transition from tachycardia to bradycardia may suggest the development of right ventricular strain and potentially cardiogenic shock.

New-onset atrial fibrillation: This is a less common feature of PE, occurring in less than 10% of cases. Atrial flutter, atrial fibrillation, and premature beats should alert the doctor to possible right-heart strain.

Bradycardia: This is not a classic feature of PE. However, if a patient with PE transitions from tachycardia to bradycardia, it may suggest the development of right ventricular strain and potentially cardiogenic shock.

In summary, dyspnoea, tachypnoea, tachycardia, and new-onset atrial fibrillation are some of the common symptoms and signs of PE. It is important to have a high level of suspicion for PE, especially in high-risk patients, to ensure prompt diagnosis and treatment.

Pneumonia is a serious respiratory infection that requires prompt assessment and management. In the primary care setting, the CRB65 criteria are used to stratify patients based on their risk of mortality. Patients with a score of 0 are considered low risk and may be treated at home, while those with a score of 3 or 4 are high risk and require urgent admission to hospital. The use of a point-of-care CRP test can help guide antibiotic therapy. In the secondary care setting, the CURB65 criteria are used, which includes an additional criterion of urea > 7 mmol/L. Chest x-rays and blood and sputum cultures are recommended for intermediate or high-risk patients. Treatment for low-severity community acquired pneumonia typically involves a 5-day course of amoxicillin, while moderate and high-severity cases may require dual antibiotic therapy for 7-10 days. Discharge criteria and advice post-discharge are also provided, including information on expected symptom resolution timeframes and the need for a repeat chest x-ray at 6 weeks.

Understanding PEFR and Its Role in Diagnosing Asthma

Peak expiratory flow rate (PEFR) is a valuable tool in both the diagnosis and management of asthma. It is measured by a maximal forced expiration through a peak-flow meter and correlates well with forced expiratory volume in one second (FEV1), providing an estimate of airway calibre. Patients with asthma can monitor their PEFR at home to track disease control. A PEFR <80% of predicted is a strong indicator of obstructive airway disease, such as asthma. However, it’s important to note that PEFR is not affected by restrictive defects, such as those caused by kyphoscoliosis. Bronchial carcinoma itself does not cause airflow limitation, but a co-morbid obstructive lung disease, such as asthma or COPD, could produce abnormal PEFR readings. Bronchiectasis can cause an obstructive pattern on spirometry, but it would not typically cause a reduction in PEFR. Whooping cough, despite causing inflammation of the airways, would not typically result in the markedly reduced PEFR readings seen in asthma. In conclusion, understanding PEFR and its role in diagnosing asthma is crucial for both patients and healthcare providers. By monitoring PEFR at home and seeking medical attention when necessary, individuals with asthma can better manage their condition and improve their quality of life.

Identifying the Probable Cause of Pulmonary Fibrosis

Methotrexate is the correct answer as it is a well-known drug-related cause of pulmonary fibrosis, which is the probable cause of the patient’s symptoms. Hydroxychloroquine, azathioprine, ciclosporin, and penicillamine are not known to cause pulmonary fibrosis, although some of them have the potential to cause pneumonitis. Ciclosporin has been studied as a treatment for the disease, but it is not recommended by NICE. Therefore, it is important to identify the probable cause of pulmonary fibrosis to provide appropriate treatment and prevent further complications.

Emphysema: Imbalance between Proteases and Anti-Proteases in the Lungs

Emphysema is a lung disease that results from an imbalance between proteases and anti-proteases within the lung. This imbalance is often caused by a1-antitrypsin deficiency, which is associated with the development of emphysema in young people with no history of smoking and a positive family history. The interplay between environmental and genetic factors determines the onset of emphysema. Patients typically present with worsening dyspnoea, and weight loss, cor pulmonale, and polycythaemia occur later in the course of the disease. Chest radiographs show bilateral basal emphysema with paucity and pruning of the basal pulmonary vessels. Early onset of liver cirrhosis, often in combination with emphysema, is also associated with a1-antitrypsin deficiency.

Understanding Metabolic Acidosis and Anion Gap

Metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not able to remove enough acid from the body. It is commonly classified according to the anion gap, which can be calculated by subtracting the sum of chloride and bicarbonate levels from the sum of sodium and potassium levels. The normal range for anion gap is 10-18 mmol/L. If a question supplies the chloride level, it may be a clue that the anion gap should be calculated.

There are two types of metabolic acidosis based on anion gap levels. Normal anion gap or hyperchloraemic metabolic acidosis is caused by gastrointestinal bicarbonate loss, prolonged diarrhea, ureterosigmoidostomy, fistula, renal tubular acidosis, drugs, ammonium chloride injection, and Addison’s disease. On the other hand, raised anion gap is caused by lactate, ketones, urate, acid poisoning, and other factors.

Metabolic acidosis secondary to high lactate levels may be subdivided into two types: lactic acidosis type A and lactic acidosis type B. Lactic acidosis type A is caused by sepsis, shock, hypoxia, and burns, while lactic acidosis type B is caused by metformin. Understanding the different types of metabolic acidosis and anion gap levels can help in diagnosing and treating the condition.

Understanding Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic lung condition that causes progressive fibrosis of the interstitium of the lungs. Unlike other causes of lung fibrosis, IPF has no underlying cause. It is typically seen in patients aged 50-70 years and is more common in men.

The symptoms of IPF include progressive exertional dyspnoea, dry cough, clubbing, and bibasal fine end-inspiratory crepitations on auscultation. Diagnosis is made through spirometry, impaired gas exchange tests, and imaging such as chest x-rays and high-resolution CT scans.

Management of IPF includes pulmonary rehabilitation, but very few medications have been shown to be effective. Some evidence suggests that pirfenidone, an antifibrotic agent, may be useful in selected patients. Many patients will eventually require supplementary oxygen and a lung transplant.

The prognosis for IPF is poor, with an average life expectancy of around 3-4 years. CT scans can show advanced pulmonary fibrosis, including honeycombing. While there is no cure for IPF, early diagnosis and management can help improve quality of life and potentially prolong survival.

The recommended initial investigation for suspected occupational asthma is serial peak expiratory flow rates at home and at work, according to SIGN (Scottish Intercollegiate Guidelines Network) referenced by NICE. CT of the thorax is inappropriate due to high radiation doses and chest radiograph is not part of the initial work-up for occupational asthma as it is unlikely to show specific evidence. Skin-prick testing is only recommended for high-molecular-weight agents and spirometry is not recommended as an initial investigation for occupational asthma, but may be appropriate for surveillance in industries with risk of the condition.

If a patient with chest wall trauma presents with elevated JVP, persistent hypotension, and tachycardia despite fluid resuscitation, cardiac tamponade should be considered. In such cases, pericardial needle aspiration is the correct course of action. Beck’s triad, which includes hypotension, muffled (distant) heart sounds, and elevated JVP, is a characteristic feature of cardiac tamponade. Urgent aspiration of the pericardium is necessary to prevent further haemodynamic compromise and save the patient’s life. Although the patient may have associated rib fractures, managing the cardiac tamponade should take priority as it poses the greatest threat in this scenario. CT scan of the chest, chest drain insertion into the triangle of safety, and needle decompression 2nd intercostal space, midclavicular line are not appropriate management options in this case.

Cardiac tamponade is a condition where there is an accumulation of fluid in the pericardial sac, which puts pressure on the heart. This can lead to a range of symptoms, including hypotension, raised JVP, muffled heart sounds, dyspnoea, tachycardia, and pulsus paradoxus. One of the key features of cardiac tamponade is the absence of a Y descent on the JVP, which is due to limited right ventricular filling. Other diagnostic criteria include Kussmaul’s sign and electrical alternans on an ECG. Constrictive pericarditis is a similar condition, but it can be distinguished from cardiac tamponade by the presence of an X and Y descent on the JVP, the absence of pulsus paradoxus, and the presence of pericardial calcification on a chest X-ray. The management of cardiac tamponade involves urgent pericardiocentesis to relieve the pressure on the heart.

Angiotensin II receptor blockers may be considered for hypertension patients who experience cough as a side effect of ACE inhibitors. This is especially relevant for elderly patients, as ACE inhibitors or angiotensin II receptor blockers are the preferred initial treatment options for hypertension.

Angiotensin II receptor blockers are a type of medication that is commonly used when patients cannot tolerate ACE inhibitors due to the development of a cough. Examples of these blockers include candesartan, losartan, and irbesartan. However, caution should be exercised when using them in patients with renovascular disease. Side-effects may include hypotension and hyperkalaemia.

The mechanism of action for angiotensin II receptor blockers is to block the effects of angiotensin II at the AT1 receptor. These blockers have been shown to reduce the progression of renal disease in patients with diabetic nephropathy. Additionally, there is evidence to suggest that losartan can reduce the mortality rates associated with CVA and IHD in hypertensive patients.

Overall, angiotensin II receptor blockers are a viable alternative to ACE inhibitors for patients who cannot tolerate the latter. They have a proven track record of reducing the progression of renal disease and improving mortality rates in hypertensive patients. However, as with any medication, caution should be exercised when using them in patients with certain medical conditions.

Dealing with Choking Emergencies

Choking is a serious medical emergency that can be life-threatening. It occurs when the airway is partially or completely blocked, often while eating. The first step in dealing with a choking victim is to ask them if they are choking. If they are able to speak and breathe, it may be a mild obstruction. However, if they are unable to speak or breathe, it is a severe obstruction and requires immediate action.

According to the Resus Council, mild airway obstruction can be treated by encouraging the patient to cough. However, if the obstruction is severe and the patient is conscious, up to five back-blows and abdominal thrusts can be given. If these methods are unsuccessful, the cycle should be repeated. If the patient is unconscious, an ambulance should be called and CPR should be started.

It is important to note that choking can happen to anyone, so it is important to be prepared and know how to respond in an emergency. By following these steps, you can help save a life.

The PESI score is suggested by BTS guidelines for identifying patients with pulmonary embolism who can be treated as outpatients. It predicts long-term morbidity and mortality in PE patients. The ABCD2 is used for triaging acute Transient Ischaemic Attack cases. The CHA2DS2-VASc score aids in deciding whether to start prophylactic anticoagulation in atrial fibrillation patients. The GRACE score estimates mortality in those who have had Acute Coronary Syndrome.

Management of Pulmonary Embolism: NICE Guidelines

Pulmonary embolism (PE) is a serious condition that requires prompt management. The National Institute for Health and Care Excellence (NICE) updated their guidelines on the management of venous thromboembolism (VTE) in 2020, with some key changes. One of the significant changes is the recommendation to use direct oral anticoagulants (DOACs) as the first-line treatment for most people with VTE, including those with active cancer. Another change is the increasing use of outpatient treatment for low-risk PE patients, determined by a validated risk stratification tool.

Anticoagulant therapy is the cornerstone of VTE management, and the guidelines recommend using apixaban or rivaroxaban as the first-line treatment following the diagnosis of a PE. If neither of these is suitable, LMWH followed by dabigatran or edoxaban or LMWH followed by a vitamin K antagonist (VKA) can be used. For patients with active cancer, DOACs are now recommended instead of LMWH. The length of anticoagulation is determined by whether the VTE was provoked or unprovoked, with treatment typically stopped after 3-6 months for provoked VTE and continued for up to 6 months for unprovoked VTE.

In cases of haemodynamic instability, thrombolysis is recommended as the first-line treatment for massive PE with circulatory failure. Patients who have repeat pulmonary embolisms, despite adequate anticoagulation, may be considered for inferior vena cava (IVC) filters. However, the evidence base for IVC filter use is weak.

Overall, the updated NICE guidelines provide clear recommendations for the management of PE, including the use of DOACs as first-line treatment and outpatient management for low-risk patients. The guidelines also emphasize the importance of individualized treatment based on risk stratification and balancing the risks of VTE recurrence and bleeding.

According to the British Thoracic Society (BTS), chest tube placement in pleural infection is mainly indicated for patients with purulent or cloudy pleural fluid, positive Gram stain and/or culture results from non-purulent pleural fluid, and pleural fluid pH below 7.2. Among these indications, pleural fluid pH is considered the most valuable test.

Investigating and Managing Pleural Effusion: BTS Guidelines

Pleural effusion is a condition where fluid accumulates in the pleural space, the area between the lungs and the chest wall. To investigate and manage this condition, the British Thoracic Society (BTS) has provided guidelines.

Imaging is an essential part of the investigation process, and the BTS recommends performing posterioranterior (PA) chest x-rays in all patients. Ultrasound is also recommended as it increases the likelihood of successful pleural aspiration and is sensitive for detecting pleural fluid septations. Contrast CT is increasingly performed to investigate the underlying cause, particularly for exudative effusions.

Pleural aspiration is another crucial step in the investigation process. The BTS recommends using ultrasound to reduce the complication rate. A 21G needle and 50ml syringe should be used, and fluid should be sent for pH, protein, lactate dehydrogenase (LDH), cytology, and microbiology. Light’s criteria can help distinguish between a transudate and an exudate. Other characteristic pleural fluid findings include low glucose in rheumatoid arthritis and tuberculosis, raised amylase in pancreatitis and oesophageal perforation, and heavy blood staining in mesothelioma, pulmonary embolism, and tuberculosis.

In cases of pleural infection, diagnostic pleural fluid sampling is required for all patients with a pleural effusion in association with sepsis or a pneumonic illness. If the fluid is purulent or turbid/cloudy, a chest tube should be placed to allow drainage. If the fluid is clear but the pH is less than 7.2 in patients with suspected pleural infection, a chest tube should be placed.

For managing recurrent pleural effusion, options include recurrent aspiration, pleurodesis, indwelling pleural catheter, and drug management to alleviate symptoms such as opioids to relieve dyspnoea. The BTS guidelines provide a comprehensive approach to investigating and managing pleural effusion.

Understanding SIADH: The Syndrome of Inappropriate Antidiuretic Hormone Secretion

SIADH, or the syndrome of inappropriate antidiuretic hormone secretion, is a condition where the body produces too much vasopressin (ADH), leading to overhydration in both the intracellular and extracellular compartments. This can result in dilutional hyponatraemia, where the sodium concentration falls to dangerous levels. Symptoms may include drowsiness, lethargy, irritability, mental confusion, and disorientation, with seizures and coma being the most severe features.

SIADH can develop as a paraneoplastic syndrome, most commonly in patients with small-cell carcinoma of the lung. However, it can also be associated with various other neoplastic and non-neoplastic pathologies, as well as certain medications. Treatment for SIADH may involve restriction of fluids, demeclocycline, or other interventions, but caution must be taken to avoid complications such as cardiac failure, cerebral oedema, or central pontine myelinolysis.

While a sodium-restricted diet or sodium-reduced water drinking may contribute to hyponatraemia, they are unlikely to cause such severe levels in the absence of other medical conditions. Liver metastases and bone metastases may also be associated with hyponatraemia, but in the context of a known diagnosis of small-cell lung cancer, SIADH is the most likely explanation.

Overall, understanding SIADH and its potential causes and treatments is crucial for managing hyponatraemia and preventing serious complications.

While the combined oral contraceptive pill may increase the risk of breast and cervical cancer, it has been found to provide protection against ovarian and endometrial cancer. In fact, studies have shown that the pill can actually decrease the risk of ovarian cancer.

Pros and Cons of the Combined Oral Contraceptive Pill

The combined oral contraceptive pill is a highly effective method of birth control with a failure rate of less than 1 per 100 woman years. It does not interfere with sexual activity and its contraceptive effects are reversible upon stopping. Additionally, it can make periods regular, lighter, and less painful, and may reduce the risk of ovarian, endometrial, and colorectal cancer. It may also protect against pelvic inflammatory disease, ovarian cysts, benign breast disease, and acne vulgaris.

However, there are also some disadvantages to the combined oral contraceptive pill. One of the main issues is that people may forget to take it, which can reduce its effectiveness. It also offers no protection against sexually transmitted infections. There is an increased risk of venous thromboembolic disease, breast and cervical cancer, stroke, and ischaemic heart disease, especially in smokers. Temporary side-effects such as headache, nausea, and breast tenderness may also be experienced.

It is important to weigh the pros and cons of the combined oral contraceptive pill before deciding if it is the right method of birth control for you. While some users report weight gain while taking the pill, a Cochrane review did not support a causal relationship. Overall, the combined oral contraceptive pill can be an effective and convenient method of birth control, but it is important to discuss any concerns or potential risks with a healthcare provider.

Treatment options for Mycoplasma pneumoniae infection

Mycoplasma pneumoniae is a bacterium that causes atypical pneumonia and is transmitted through respiratory droplets. The symptoms vary but can include fever, malaise, myalgia, headache, and a rash. Diagnosis is usually confirmed with serology, and treatment typically involves a macrolide antibiotic such as clarithromycin for at least 10-14 days. Penicillin and other beta-lactam antibiotics are ineffective as Mycoplasma pneumoniae lacks a cell wall. Tetracycline can be used but macrolides are preferred due to a better side-effect profile. Rifampicin is mostly limited to the treatment of tuberculosis and leprosy, while co-trimoxazole is not indicated for Mycoplasma pneumoniae infection. Extrapulmonary involvement is possible and may suggest the diagnosis in a patient presenting with pneumonia. A chest radiograph is non-specific and typically shows a reticulonodular or patchy consolidation pattern.

The 2015 Resus Council guidelines for adult advanced life support outline the steps to be taken when dealing with patients with shockable and non-shockable rhythms. For both types of patients, chest compressions are a crucial part of the process, with a ratio of 30 compressions to 2 ventilations. Defibrillation is recommended for shockable rhythms, with a single shock for VF/pulseless VT followed by 2 minutes of CPR. Adrenaline and amiodarone are the drugs of choice for non-shockable rhythms, with adrenaline given as soon as possible and amiodarone administered after 3 shocks for VF/pulseless VT. Thrombolytic drugs should be considered if a pulmonary embolus is suspected. Atropine is no longer recommended for routine use in asystole or PEA. Oxygen should be titrated to achieve saturations of 94-98% following successful resuscitation. The Hs and Ts should be considered as potential reversible causes of cardiac arrest.

This presentation is characteristic of acute sickle chest syndrome.

Sickle cell anaemia is a condition that involves periods of good health with intermittent crises. There are several types of crises that can occur, including thrombotic or painful crises, sequestration, acute chest syndrome, aplastic, and haemolytic. Thrombotic crises, also known as painful crises or vaso-occlusive crises, are triggered by factors such as infection, dehydration, and deoxygenation. These crises are diagnosed clinically and can result in infarcts in various organs, including the bones, lungs, spleen, and brain.

Sequestration crises occur when sickling occurs within organs such as the spleen or lungs, leading to pooling of blood and worsening of anaemia. This type of crisis is associated with an increased reticulocyte count. Acute chest syndrome is caused by vaso-occlusion within the pulmonary microvasculature, resulting in infarction in the lung parenchyma. Symptoms include dyspnoea, chest pain, pulmonary infiltrates on chest x-ray, and low pO2. Management involves pain relief, respiratory support, antibiotics, and transfusion.

Aplastic crises are caused by infection with parvovirus and result in a sudden fall in haemoglobin. Bone marrow suppression leads to a reduced reticulocyte count. Haemolytic crises are rare and involve a fall in haemoglobin due to an increased rate of haemolysis. It is important to recognise and manage these crises promptly, as they can lead to serious complications and even death.

Understanding the Two-Level PE Wells Score: Clinical Signs and Symptoms of DVT

The Two-Level PE Wells Score is a tool used to assess the likelihood of a patient having a pulmonary embolism (PE). One of the key factors in this score is the presence of clinical signs and symptoms of a deep-vein thrombosis (DVT), which includes leg swelling and pain on palpation of the deep veins. This carries three points in the score, and is a crucial factor in determining the likelihood of a PE.

Other factors in the score include an alternative diagnosis being less likely than a PE, heart rate over 100 beats/min, immobilization or recent surgery, previous DVT/PE, haemoptysis, and malignancy. Each of these factors carries a certain number of points, and a score of over 4 points indicates a high likelihood of a PE, while a score of 4 points or less indicates a lower likelihood.

Overall, understanding the Two-Level PE Wells Score and the clinical signs and symptoms of DVT is important in accurately assessing the likelihood of a patient having a PE and determining the appropriate course of treatment.

Differential Diagnosis for a Patient with Cough and Fever: Bronchopneumonia vs. Other Conditions

Bronchopneumonia is a common condition that presents with a cough and fever, along with other symptoms such as sputum production, dyspnea, and pleuritic pain. Examination findings may include decreased breath sounds and focal chest signs. A chest radiograph can confirm the diagnosis. In primary care, a CRB-65 score is used to assess mortality risk and determine where to treat the patient: one point each for acute confusion, respiratory rate (RR) ≥30/min, systolic blood pressure (BP) <90 mmHg or diastolic BP <60 mmHg, age >65 years).
CRB-65 score Mortality risk (%) – Where to treat
0 <1 At home
1-2 1-10 Hospital advised, particularly score of 2
3-4 >10 Hospital advised, may require stay in intensive therapy unit (ITU).

Other conditions that may present with similar symptoms include pneumothorax, pulmonary embolism, malignant mesothelioma, and tuberculosis. However, these conditions have distinct features that differentiate them from bronchopneumonia. For example, pneumothorax involves partial or full collapse of a lung, while pulmonary embolism results from obstruction of one or more of the pulmonary arteries. Malignant mesothelioma is a cancer that affects the pleura and peritoneum, and tuberculosis usually presents with a persistent productive cough, weight loss, night sweats, fevers, lymphadenopathy, and general malaise.

It is important to consider these differentials when evaluating a patient with cough and fever, and to use appropriate diagnostic tools to confirm the diagnosis and determine the best course of treatment.

Treatment Options for COPD Exacerbations: Antibiotics and Corticosteroids

COPD exacerbations are characterized by a sudden worsening of symptoms beyond the patient’s usual stable state. These symptoms include increased breathlessness, cough, sputum production, and changes in sputum color. To treat exacerbations, a combination of antibiotics and corticosteroids is often used.

Oral corticosteroids, such as prednisolone, should be prescribed for five days to patients experiencing a significant increase in breathlessness that interferes with daily activities. Antibiotics are recommended for exacerbations associated with purulent sputum, with first-line agents including amoxicillin, doxycycline, and clarithromycin.

It is important to follow local microbiologist guidance when initiating empirical antibiotic treatment. Flucloxacillin and clindamycin are not useful in treating COPD exacerbations and are recommended for other conditions such as skin infections and bacterial vaginosis, respectively. Nitrofurantoin and trimethoprim are used for urinary tract infections and may be considered as first or second-line agents depending on antibiotic resistance and previous sensitivity.

According to NICE 2017 guidelines, if a patient with asthma is not effectively managed with a SABA + ICS, the first step should be to add a LTRA rather than a LABA.

The management of asthma in adults has been updated by NICE in 2017, following the 2016 BTS guidelines. One of the significant changes is in ‘step 3’, where patients on a SABA + ICS whose asthma is not well controlled should be offered a leukotriene receptor antagonist instead of a LABA. NICE does not follow the stepwise approach of the previous BTS guidelines, but to make the guidelines easier to follow, we have added our own steps. The steps range from newly-diagnosed asthma to SABA +/- LTRA + one of the following options, including increasing ICS to high-dose, a trial of an additional drug, or seeking advice from a healthcare professional with expertise in asthma. Maintenance and reliever therapy (MART) is a form of combined ICS and LABA treatment that is only available for ICS and LABA combinations in which the LABA has a fast-acting component. It should be noted that NICE does not recommend changing treatment in patients who have well-controlled asthma simply to adhere to the latest guidance. The definitions of what constitutes a low, moderate, or high-dose ICS have also changed, with <= 400 micrograms budesonide or equivalent being a low dose, 400 micrograms - 800 micrograms budesonide or equivalent being a moderate dose, and > 800 micrograms budesonide or equivalent being a high dose for adults.

Bacterial Causes of Acute COPD Exacerbation

Acute exacerbation of chronic obstructive pulmonary disease (COPD) can be caused by various bacterial pathogens. Among them, Haemophilus influenzae is the most common, followed by Streptococcus pneumoniae and Moraxella catarrhalis. Staphylococcus aureus and Staphylococcus epidermidis are less likely to cause COPD exacerbation unless there is an underlying immunodeficiency. Symptoms of bacterial infection include breathlessness, productive cough, and malaise. Treatment with doxycycline can effectively manage Haemophilus influenzae infection.

Pleural plaques are benign and do not develop into cancerous growths, so there is no need for any follow-up. These plaques are the most common form of lung disease caused by asbestos exposure, but they do not increase the risk of lung cancer or mesothelioma. While ongoing monitoring of the patient’s lung disease is recommended, there is no need to specifically monitor the pleural plaques. It is important to note that pleural plaques are a sign of past asbestos exposure, which could increase the risk of mesothelioma, but the plaques themselves are not a cause for concern. Therefore, the patient does not require a specialist referral for the pleural plaques alone. However, if the patient experiences worsening shortness of breath or frequent exacerbations, a specialist referral may be necessary to assess for disease progression or malignancy.

Asbestos-Related Lung Diseases

Asbestos exposure can lead to various lung diseases, ranging from benign pleural plaques to malignant mesothelioma. Pleural plaques are non-cancerous and do not require any follow-up, but they are the most common form of asbestos-related lung disease and typically appear after a latent period of 20-40 years. Asbestos exposure may also cause diffuse pleural thickening, which is similar to the pattern seen after an empyema or haemothorax, but the underlying pathophysiology is not fully understood.

Asbestosis is a lung disease that is related to the length of exposure to asbestos. It causes lower lobe fibrosis and is typically characterized by dyspnea, reduced exercise tolerance, clubbing, bilateral end-inspiratory crackles, and a restrictive pattern with reduced gas transfer on lung function tests. Asbestosis is treated conservatively, as no interventions offer significant benefits. The latent period for asbestosis is typically 15-30 years.

Mesothelioma is a malignant disease of the pleura that is caused by asbestos exposure, with crocidolite (blue) asbestos being the most dangerous form. Possible features of mesothelioma include progressive shortness-of-breath, chest pain, and pleural effusion. Patients are usually offered palliative chemotherapy, and there is a limited role for surgery and radiotherapy. Unfortunately, the prognosis for mesothelioma is very poor, with a median survival from diagnosis of 8-14 months.

Although mesothelioma is often associated with asbestos exposure, lung cancer is actually the most common form of cancer related to asbestos exposure. It has a synergistic effect with cigarette smoke, which increases the risk of developing lung cancer.

If a lung abscess is not responding to intravenous antibiotics, percutaneous drainage should be considered as an option.

Correct: Arrange CT-guided percutaneous drainage. This is because the patient’s symptoms, such as swinging fevers, night sweats, pleuritic chest pain, dyspnoea, and cough, are consistent with a lung abscess. The chest x-ray also supports this diagnosis by showing a fluid-filled space within an area of consolidation. If IV antibiotics are not effective, percutaneous drainage can be guided by a CT scan or ultrasound. IV antibiotics may not be able to penetrate the abscess wall, which is why some patients do not respond to this treatment.

Incorrect: Arrange bronchoscopy. This is not commonly used for lung abscesses and is only indicated if an underlying tumour or foreign body is suspected. It is performed for diagnosis only, not drainage.

Incorrect: Arrange sputum cytology. Sputum cultures have already been collected, and a diagnosis of lung abscess has been established. This option could be considered later if the patient still does not respond to treatment to rule out an underlying malignancy.

Incorrect: Prescribe broad-spectrum IV antibiotics. This option is unlikely to be effective since the patient has already received IV antibiotics without success. The next step would be to manually drain the abscess.

Understanding Lung Abscess

A lung abscess is a localized infection that occurs within the lung tissue. It is commonly caused by aspiration pneumonia, which can be triggered by poor dental hygiene, reduced consciousness, or previous stroke. Other potential causes include haematogenous spread, direct extension, and bronchial obstruction. The infection is typically polymicrobial, with Staphylococcus aureus, Klebsiella pneumonia, and Pseudomonas aeruginosa being the most common monomicrobial causes.

The symptoms of lung abscess are similar to pneumonia, but they tend to develop more slowly over several weeks. Patients may experience fever, productive cough, foul-smelling sputum, chest pain, and dyspnea. Some may also have systemic features such as night sweats and weight loss, while a minority may experience haemoptysis. Physical examination may reveal dull percussion and bronchial breathing, as well as clubbing in some cases.

To diagnose lung abscess, a chest x-ray is usually performed, which shows a fluid-filled space within an area of consolidation. Sputum and blood cultures should also be obtained to identify the causative organism. Treatment typically involves intravenous antibiotics, but if the infection does not resolve, percutaneous drainage or surgical resection may be required in rare cases.

Understanding the Indicators of Acute Asthma Exacerbations

Acute asthma exacerbations can range from mild to life-threatening, and it is important to recognize the indicators of each level of severity. In a severe exacerbation, the individual may not be able to complete full sentences, have a peak expiratory flow rate of 33-50% best or predicted, a respiratory rate of ≥25 breaths/min, a heart rate of ≥110 beats/min, use of accessory muscles, and oxygen saturation of ≥92%. A life-threatening exacerbation is characterized by a peak expiratory flow rate of <33% best or predicted, oxygen saturation of <92%, silent chest, cyanosis, cardiac arrhythmia or hypotension, confusion, coma, or altered consciousness. A moderate exacerbation may include talking in full sentences, a peak expiratory flow rate of >50-75% best or predicted, a respiratory rate of <25 breaths per minute, and a heart rate of <110 beats/min. Finally, a life-threatening exacerbation may also include a peak expiratory flow rate of <33% best or predicted, oxygen saturation of <92%, silent chest, cyanosis, cardiac arrhythmia or hypotension, confusion, coma, or altered consciousness, as well as exhaustion and poor respiratory effort. It is important to understand these indicators in order to properly assess and treat acute asthma exacerbations.

Pulmonary Function Tests: Understanding Tidal Volume, Total Lung Capacity, Residual Volume, FEV1/FVC Ratio, and FEV1

Pulmonary function tests (PFTs) are a group of tests that measure how well the lungs are functioning. There are several parameters that are measured during PFTs, including tidal volume (TV), total lung capacity (TLC), residual volume (RV), forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio, and forced expiratory volume in 1 second (FEV1).

Tidal volume refers to the amount of gas inspired or expired with each breath. It can be reduced in both obstructive and restrictive lung disease, but the underlying mechanism causing the reduction is different. In obstructive lung disease, there is airflow limitation, while in restrictive lung disease, there is reduced lung volume or inability to fully expand the thoracic cage.

Total lung capacity is the volume of air in the lungs after a maximal inspiration. It is increased in obstructive lung disease due to air trapping, but is reduced in restrictive lung disease.

Residual volume is the volume of air remaining in the lungs after a maximal expiration. It cannot be measured with spirometry, but it is increased in obstructive lung disease due to air trapping.

The FEV1/FVC ratio is a measure of how much air a person can forcefully exhale in one second compared to the total amount of air they can exhale. A ratio of less than 70% is indicative of obstructive lung disease, while a ratio greater than 70% is indicative of restrictive lung disease.

FEV1 is the amount of air a person can forcefully exhale in one second. It is characteristically reduced in obstructive lung disease, but normal in restrictive lung disease because there is no airflow limitation.

Understanding these parameters can help healthcare professionals diagnose and manage lung diseases.

For an adult with asthma that is not controlled by a short-acting beta-agonist, the appropriate next step is to add a low-dose inhaled corticosteroid. This is in accordance with NICE guidelines. The addition of a combined inhaled corticosteroid and long-acting beta-agonist is not recommended until symptoms cannot be controlled with a low-dose inhaled corticosteroid and a short-acting beta-agonist, with or without a leukotriene receptor antagonist. Similarly, a leukotriene receptor antagonist or long-acting beta-agonist should not be introduced until symptoms are not controlled with a low-dose inhaled corticosteroid and a short-acting beta-agonist, with or without a leukotriene receptor antagonist.

The management of asthma in adults has been updated by NICE in 2017, following the 2016 BTS guidelines. One of the significant changes is in ‘step 3’, where patients on a SABA + ICS whose asthma is not well controlled should be offered a leukotriene receptor antagonist instead of a LABA. NICE does not follow the stepwise approach of the previous BTS guidelines, but to make the guidelines easier to follow, we have added our own steps. The steps range from newly-diagnosed asthma to SABA +/- LTRA + one of the following options, including increasing ICS to high-dose, a trial of an additional drug, or seeking advice from a healthcare professional with expertise in asthma. Maintenance and reliever therapy (MART) is a form of combined ICS and LABA treatment that is only available for ICS and LABA combinations in which the LABA has a fast-acting component. It should be noted that NICE does not recommend changing treatment in patients who have well-controlled asthma simply to adhere to the latest guidance. The definitions of what constitutes a low, moderate, or high-dose ICS have also changed, with <= 400 micrograms budesonide or equivalent being a low dose, 400 micrograms - 800 micrograms budesonide or equivalent being a moderate dose, and > 800 micrograms budesonide or equivalent being a high dose for adults.

In cases where a patient with COPD is still experiencing breathlessness despite using SABA/SAMA and exhibits asthma/steroid responsive features, the next step in treatment would be to add a LABA/ICS inhaler. This is the most appropriate option due to the presence of asthmatic features and indications of steroid responsiveness, such as a raised eosinophil count and diurnal variation. Azithromycin prophylaxis is not recommended at this point, as it is typically reserved for patients who have already optimized standard treatments and continue to experience exacerbations. While a LAMA inhaler may be introduced in the future as part of a triple therapy combination if control remains poor, it is not a stepwise increase in treatment and is less appropriate than a LABA/ICS inhaler in this case. Similarly, a LAMA/LABA inhaler would only be suitable if the patient did not exhibit asthmatic features or indications of steroid responsiveness. The use of theophylline is only recommended after trials of short and long-acting bronchodilators or for patients who cannot use inhaled therapy, and should be done with the input of a respiratory specialist. Therefore, it is not an appropriate next step in treatment for this patient.

NICE guidelines recommend smoking cessation advice, annual influenza and one-off pneumococcal vaccinations, and pulmonary rehabilitation for COPD patients. Bronchodilator therapy is first-line treatment, with the addition of LABA and LAMA for patients without asthmatic features and LABA, ICS, and LAMA for those with asthmatic features. Theophylline is recommended after trials of bronchodilators or for patients who cannot use inhaled therapy. Azithromycin prophylaxis is recommended in select patients. Mucolytics should be considered for patients with a chronic productive cough. Loop diuretics and long-term oxygen therapy may be used for cor pulmonale. Smoking cessation and long-term oxygen therapy may improve survival in stable COPD patients. Lung volume reduction surgery may be considered in selected patients.