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.

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.

When medical therapy fails to improve COPD exacerbations, patients should be given BiPAP non-invasive ventilation. Before starting non-invasive ventilation, an arterial blood gas should be taken. BiPAP delivers two different pressures for inhalation and exhalation, making it a useful tool for patients who need help with ventilation, such as those in type II respiratory failure. On the other hand, CPAP delivers one pressure setting and is more helpful in increasing oxygen saturation and intrathoracic pressure to reduce preload and cardiac workload in chronic heart failure or sleep apnea. While intravenous magnesium sulfate is part of the management for severe asthma exacerbation, there is currently insufficient evidence to support its use in COPD exacerbation. If non-invasive ventilatory support fails, intubation and ventilation may be necessary.

Acute exacerbations of COPD are a common reason for hospital visits in developed countries. The most common causes of these exacerbations are bacterial infections, with Haemophilus influenzae being the most common culprit, followed by Streptococcus pneumoniae and Moraxella catarrhalis. Respiratory viruses also account for around 30% of exacerbations, with human rhinovirus being the most important pathogen. Symptoms of an exacerbation include an increase in dyspnea, cough, and wheezing, as well as hypoxia and acute confusion in some cases.

NICE guidelines recommend increasing the frequency of bronchodilator use and giving prednisolone for five days. Antibiotics should only be given if sputum is purulent or there are clinical signs of pneumonia. Admission to the hospital is recommended for patients with severe breathlessness, acute confusion or impaired consciousness, cyanosis, oxygen saturation less than 90%, social reasons, or significant comorbidity.

For severe exacerbations requiring secondary care, oxygen therapy should be used with an initial saturation target of 88-92%. Nebulized bronchodilators such as salbutamol and ipratropium should also be administered, along with steroid therapy. IV hydrocortisone may be considered instead of oral prednisolone, and IV theophylline may be used for patients not responding to nebulized bronchodilators. Non-invasive ventilation may be used for patients with type 2 respiratory failure, with bilevel positive airway pressure being the typical method used.

The most likely diagnosis for this patient is lung abscess, as they are presenting with a subacute productive cough, foul-smelling sputum, and night sweats. The duration of a cough can be categorized as acute, subacute, or chronic, and this patient falls under the subacute category. The patient’s recent history of aspiration pneumonia and examination findings, such as dullness on percussion, bronchial breath sounds, and fever, support the diagnosis of lung abscess.

Lung cancer is not the most likely diagnosis for this patient, as they do not have weight loss and have other findings that point towards lung abscess. Pulmonary fibrosis is also unlikely, as it is rare to have unilateral pulmonary fibrosis, and the patient’s examination findings do not support this diagnosis. Recurrent pneumonia is a good differential, but the presence of bronchial breath sounds and night sweats make lung abscess a more likely diagnosis.

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.

This patient is at a high risk of having a PE, scoring 7 points on her Wells’ score and presenting with a typical history of PE, along with several risk factors such as immobilisation and being on the COCP. Ideally, a CT pulmonary angiogram would be performed, but a contrast allergy is an absolute contraindication. Giving fluids or hydrocortisone and chlorphenamine would not reduce the risk of contrast allergy. A CT chest without contrast is not diagnostic for a PE. In such cases, a V/Q scan is the best option, but it may not be available out of hours. Therefore, given the strong suspicion of a PE, the patient should be started on treatment dose anticoagulation while awaiting the scan. NICE recommends using DOACs like apixaban as interim therapeutic anticoagulation. It is important to note that prophylactic heparin is used to prevent a PE, not to treat a PE.

Investigating Pulmonary Embolism: Key Features and Diagnostic Criteria

Pulmonary embolism (PE) can be challenging to diagnose as it can present with a wide range of cardiorespiratory symptoms and signs depending on its location and size. The PIOPED study in 2007 found that tachypnea, crackles, tachycardia, and fever were the most common clinical signs associated with PE. To aid in the diagnosis of PE, NICE updated their guidelines in 2020 to include the use of the pulmonary embolism rule-out criteria (PERC) and the 2-level PE Wells score. The PERC rule should be used when there is a low pre-test probability of PE, and a negative PERC result reduces the probability of PE to less than 2%. The 2-level PE Wells score should be performed if a PE is suspected, with a score of more than 4 points indicating a likely PE and a score of 4 points or less indicating an unlikely PE.

If a PE is likely, an immediate computed tomography pulmonary angiogram (CTPA) should be arranged, and interim therapeutic anticoagulation should be given if there is a delay in getting the CTPA. If a PE is unlikely, a D-dimer test should be arranged, and if positive, an immediate CTPA should be performed. The consensus view from the British Thoracic Society and NICE guidelines is that CTPA is the recommended initial lung-imaging modality for non-massive PE. However, V/Q scanning may be used initially if appropriate facilities exist, the chest x-ray is normal, and there is no significant symptomatic concurrent cardiopulmonary disease.

Other diagnostic tools include age-adjusted D-dimer levels, ECG, chest x-ray, V/Q scan, and CTPA. It is important to note that a chest x-ray is recommended for all patients to exclude other pathology, but it is typically normal in PE. While investigating PE, it is crucial to consider other differential diagnoses and to tailor the diagnostic approach to the individual patient’s clinical presentation and risk factors.

According to the 2010 NICE guidelines, patients who experience frequent exacerbations of COPD should be provided with a home supply of corticosteroids and antibiotics. It is important to advise the patient to inform you if they need to use these medications and to assess if any further action is necessary. Antibiotics should only be taken if the patient is producing purulent sputum while coughing.

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.

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.

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.

Palliative care prescribing for pain is guided by NICE and SIGN guidelines. NICE recommends starting treatment with regular oral modified-release or immediate-release morphine, with immediate-release morphine for breakthrough pain. Laxatives should be prescribed for all patients initiating strong opioids, and antiemetics should be offered if nausea persists. Drowsiness is usually transient, but if it persists, the dose should be adjusted. SIGN advises that the breakthrough dose of morphine is one-sixth the daily dose, and all patients receiving opioids should be prescribed a laxative. Opioids should be used with caution in patients with chronic kidney disease, and oxycodone is preferred to morphine in patients with mild-moderate renal impairment. Metastatic bone pain may respond to strong opioids, bisphosphonates, or radiotherapy, and all patients should be considered for referral to a clinical oncologist for further treatment. When increasing the dose of opioids, the next dose should be increased by 30-50%. Conversion factors between opioids are also provided. Opioid side-effects are usually transient, such as nausea and drowsiness, but constipation can persist. In addition to strong opioids, bisphosphonates, and radiotherapy, denosumab may be used to treat metastatic bone pain.

Overall, the guidelines recommend starting with regular oral morphine and adjusting the dose as needed. Laxatives should be prescribed to prevent constipation, and antiemetics may be needed for nausea. Opioids should be used with caution in patients with chronic kidney disease, and oxycodone is preferred in patients with mild-moderate renal impairment. Metastatic bone pain may respond to strong opioids, bisphosphonates, or radiotherapy, and referral to a clinical oncologist should be considered. Conversion factors between opioids are provided, and the next dose should be increased by 30-50% when adjusting the dose. Opioid side-effects are usually transient, but constipation can persist. Denosumab may also be used to treat metastatic bone pain.

Guidelines for Emergency Oxygen Therapy

The British Thoracic Society has updated its guidelines for emergency oxygen therapy in 2017. The guidelines recommend that in critically ill patients, such as those experiencing anaphylaxis or shock, oxygen should be administered via a reservoir mask at 15 l/min. However, certain conditions, such as stable myocardial infarction, are excluded from this recommendation.

The guidelines also provide specific oxygen saturation targets for different patient groups. Acutely ill patients should aim for a saturation range of 94-98%, while patients at risk of hypercapnia, such as those with COPD, should aim for a lower range of 88-92%. Oxygen therapy should be reduced in stable patients with satisfactory oxygen saturation.

For COPD patients, a 28% Venturi mask at 4 l/min should be used prior to availability of blood gases. The target oxygen saturation range for these patients should be 88-92% if they have risk factors for hypercapnia but no prior history of respiratory acidosis. If the pCO2 is normal, the target range can be adjusted to 94-98%.

The guidelines also highlight situations where oxygen therapy should not be used routinely if there is no evidence of hypoxia. These include myocardial infarction and acute coronary syndromes, stroke, obstetric emergencies, and anxiety-related hyperventilation.

Overall, these guidelines provide clear recommendations for the administration of emergency oxygen therapy in different patient groups and situations.

Antibiotics may be prescribed for acute bronchitis if the patient has co-existing co-morbidities or is at high risk of complications. NICE guidelines advise against the use of antibiotics for those who are not systemically very unwell and not at high risk of complications. However, if the patient is very unwell or at risk of complications, antibiotics should be offered. In this case, the patient’s age, diabetes, and heart failure put him at high risk, so antibiotics should be offered in accordance with NICE guidelines. While local guidelines should be consulted, NICE recommends oral doxycycline as the first-line treatment. Inhaled bronchodilators should not be offered unless the patient has an underlying airway disease such as asthma. Oral flucloxacillin is not commonly used for respiratory tract infections, and IV co-amoxiclav is not necessary in this stable patient who can be managed without admission.

Acute bronchitis is a chest infection that typically resolves on its own within three weeks. It occurs when the trachea and major bronchi become inflamed, leading to swollen airways and the production of sputum. The primary cause of acute bronchitis is viral infection, with most cases occurring in the autumn or winter. Symptoms include a sudden onset of cough, sore throat, runny nose, and wheezing. While most patients have a normal chest examination, some may experience a low-grade fever or wheezing. It is important to differentiate acute bronchitis from pneumonia, which presents with different symptoms and chest examination findings.

Diagnosis of acute bronchitis is typically based on clinical presentation, but CRP testing may be used to determine if antibiotic therapy is necessary. Management involves pain relief and ensuring adequate fluid intake. Antibiotics may be considered for patients who are systemically unwell, have pre-existing health conditions, or have a CRP level between 20-100mg/L. Doxycycline is the recommended first-line treatment, but it cannot be used in children or pregnant women. Alternatives include amoxicillin.

Respiratory Manifestations of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory arthritis that can affect various parts of the body, including the respiratory tract. One common manifestation of RA in the respiratory system is pleural involvement, which can present as pleural effusion, pleural nodules, or pleurisy. Other respiratory complications associated with RA include pulmonary fibrosis and bronchiolitis obliterans.

It is important to note that other types of arthritis, such as ankylosing spondylitis, Behçet’s disease, gout, and psoriatic arthritis, do not typically present with respiratory complications like pleural effusion. Ankylosing spondylitis is associated with apical fibrosis, while Behçet’s disease is known for neurological complications. Gout is caused by purine metabolism abnormality and affects the joints and renal tract, while psoriatic arthritis is strongly associated with psoriasis and can lead to ocular and cardiovascular complications.

Overall, if a patient with RA presents with respiratory symptoms, it is important to consider the possibility of pleural involvement and other respiratory complications associated with the disease.

Arterial Blood Gas Interpretation Made Easy

Arterial blood gas interpretation can be a daunting task for healthcare professionals. However, the Resuscitation Council (UK) has provided a simple 5-step approach to make it easier. The first step is to assess the patient’s overall condition. The second step is to determine if the patient is hypoxaemic, which is indicated by a PaO2 level of less than 10 kPa on air. The third step is to check if the patient is acidaemic or alkalaemic, which is determined by the pH level. A pH level of less than 7.35 indicates acidaemia, while a pH level of more than 7.45 indicates alkalaemia.

The fourth step is to assess the respiratory component by checking the PaCO2 level. A PaCO2 level of more than 6.0 kPa suggests respiratory acidosis, while a PaCO2 level of less than 4.7 kPa suggests respiratory alkalosis. The fifth and final step is to evaluate the metabolic component by checking the bicarbonate level or base excess. A bicarbonate level of less than 22 mmol/l or a base excess of less than -2mmol/l indicates metabolic acidosis, while a bicarbonate level of more than 26 mmol/l or a base excess of more than +2mmol/l indicates metabolic alkalosis.

To make it easier to remember, healthcare professionals can use the ROME acronym. Respiratory is opposite, which means that low pH and high PaCO2 indicate acidosis, while high pH and low PaCO2 indicate alkalosis. Metabolic is equal, which means that low pH and low bicarbonate indicate acidosis, while high pH and high bicarbonate indicate alkalosis. By following this simple approach, healthcare professionals can easily interpret arterial blood gas results and provide appropriate treatment for their patients.

What spirometry result is expected in alpha-1 antitrypsin deficiency?

Alpha-1 antitrypsin deficiency will result in an obstructive pattern on spirometry, similar to chronic obstructive pulmonary disease (COPD). The two important factors to consider in spirometry are the FEV1 and the FEV1/FVC ratio. In obstructive disease, the FEV1 is reduced due to narrowed airways, while the FVC remains normal. This results in a reduced FEV1/FVC ratio. Therefore, in alpha-1 antitrypsin deficiency, we would expect to see a reduced FEV1 and FEV1/FVC ratio on spirometry.

Understanding Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency is a genetic condition that occurs when the liver fails to produce enough of a protein called alpha-1 antitrypsin (A1AT). A1AT is responsible for protecting cells from enzymes that can cause damage, such as neutrophil elastase. This deficiency is inherited in an autosomal recessive or co-dominant fashion, with alleles classified by their electrophoretic mobility as M for normal, S for slow, and Z for very slow. The normal genotype is PiMM, while heterozygous individuals have PiMZ. Homozygous PiSS individuals have 50% normal A1AT levels, while homozygous PiZZ individuals have only 10% normal A1AT levels.

The classic manifestation of A1AT deficiency is emphysema, which is a type of chronic obstructive pulmonary disease. This condition is most commonly seen in young, non-smoking patients. However, the evidence base is conflicting regarding the risk of emphysema. Non-smokers with A1AT deficiency are at a lower risk of developing emphysema, but they may pass on the A1AT gene to their children. Patients with A1AT deficiency who manifest disease usually have the PiZZ genotype.

In addition to emphysema, A1AT deficiency can also cause liver problems such as cirrhosis and hepatocellular carcinoma in adults, and cholestasis in children. Diagnosis is made by measuring A1AT concentrations and performing spirometry, which typically shows an obstructive pattern. Management includes avoiding smoking, supportive measures such as bronchodilators and physiotherapy, and intravenous A1AT protein concentrates. In severe cases, lung volume reduction surgery or lung transplantation may be necessary.

Risk Factors for Lung Cancer

Lung cancer is a deadly disease that can be caused by various factors. The most significant risk factor for lung cancer is smoking, which increases the risk by a factor of 10. However, other factors such as exposure to asbestos, arsenic, radon, nickel, chromate, and aromatic hydrocarbon can also increase the risk of developing lung cancer. Additionally, cryptogenic fibrosing alveolitis has been linked to an increased risk of lung cancer.

It is important to note that not all factors are related to lung cancer. For example, coal dust exposure has not been found to increase the risk of lung cancer. However, smoking and asbestos exposure are synergistic, meaning that a smoker who is also exposed to asbestos has a 50 times increased risk of developing lung cancer (10 x 5). Understanding these risk factors can help individuals make informed decisions about their health and take steps to reduce their risk of developing lung cancer.

The National Institute for Clinical Excellence (NICE) recommends that patients suspected of having an exacerbation of COPD undergo several tests, including arterial blood gases, chest X-ray, electrocardiogram, full blood count and urea and electrolytes, and theophylline level (if applicable). Sputum microscopy and culture should also be done if the sputum is purulent, and blood cultures if the patient has a fever. Medical therapy should include oxygen to maintain the patient within their individualized target range, nebulized bronchodilators, steroid therapy, antibiotics if necessary, and chest physiotherapy. If the patient does not respond well to nebulized bronchodilators, intravenous theophyllines may be considered. For patients with persistent hypercapnic ventilatory failure despite optimal medical therapy, non-invasive ventilation should be considered. In this case, a trial of BIPAP would be the best option since intravenous theophylline is not available. BIPAP is a form of non-invasive ventilation that has been proven effective in acute type two respiratory failure. It works by stenting alveoli open to increase the surface area available for ventilation and gas exchange. CPAP is another form of non-invasive ventilation but is not as effective as BIPAP in COPD. Intubation and ventilation may be necessary in some patients with COPD, but a trial of non-invasive ventilation is the most appropriate next step. It is important to set a ceiling of care for all patients presenting with an exacerbation of COPD. Regular arterial blood gas analysis is necessary to assess the patient’s response to NIV.

Acute exacerbations of COPD are a common reason for hospital visits in developed countries. The most common causes of these exacerbations are bacterial infections, with Haemophilus influenzae being the most common culprit, followed by Streptococcus pneumoniae and Moraxella catarrhalis. Respiratory viruses also account for around 30% of exacerbations, with human rhinovirus being the most important pathogen. Symptoms of an exacerbation include an increase in dyspnea, cough, and wheezing, as well as hypoxia and acute confusion in some cases.

NICE guidelines recommend increasing the frequency of bronchodilator use and giving prednisolone for five days. Antibiotics should only be given if sputum is purulent or there are clinical signs of pneumonia. Admission to the hospital is recommended for patients with severe breathlessness, acute confusion or impaired consciousness, cyanosis, oxygen saturation less than 90%, social reasons, or significant comorbidity.

For severe exacerbations requiring secondary care, oxygen therapy should be used with an initial saturation target of 88-92%. Nebulized bronchodilators such as salbutamol and ipratropium should also be administered, along with steroid therapy. IV hydrocortisone may be considered instead of oral prednisolone, and IV theophylline may be used for patients not responding to nebulized bronchodilators. Non-invasive ventilation may be used for patients with type 2 respiratory failure, with bilevel positive airway pressure being the typical method used.

The treatment of tuberculosis is a complex process that requires the expertise of a specialist in the field, such as a respiratory physician or an infectivologist. The first-line drugs used for active tuberculosis without CNS involvement are isoniazid, rifampicin, pyrazinamide, and ethambutol. These drugs are given together for the first 2 months of therapy, followed by continued treatment with just isoniazid and rifampicin for an additional 4 months. Pyridoxine is added to the treatment regimen to reduce the risk of isoniazid-induced peripheral neuropathy. If there is CNS involvement, the four drugs (and pyridoxine) are given together for 2 months, followed by continued treatment with isoniazid (with pyridoxine) and rifampicin for an additional 10 months. It is important to monitor liver function tests before and during treatment, and to educate patients on the potential side effects of the drugs and when to seek medical attention. Treatment-resistant tuberculosis cases are becoming more common and require special management and public health considerations.

Once the predicted values are obtained, the FEV1:FVC ratio can be evaluated. If this ratio is less than 70, it indicates a potential issue.

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.

Spirometry: The Best Diagnostic Tool for COPD

Chronic obstructive pulmonary disease (COPD) is a common respiratory condition that can significantly impact a patient’s quality of life. To diagnose COPD, spirometry is the best diagnostic tool. According to NICE guidelines, a diagnosis of COPD should be made based on symptoms and signs, but supported by spirometry results. Post-bronchodilator spirometry should be performed to confirm the diagnosis. Airflow obstruction is confirmed by a forced expiratory volume in 1 s (FEV1):forced vital capacity (FVC) ratio of <0.7 and FEV1 <80% predicted. Other diagnostic tools, such as CT of the chest, serial peak flow readings, and trials of beclomethasone or salbutamol, may have a role in the management of COPD, but they are not used in the diagnosis of the condition. CT of the chest may be used to investigate symptoms that seem disproportionate to the spirometric impairment, to investigate abnormalities seen on a chest radiograph, or to assess suitability for surgery. Serial peak flow readings may be appropriate if there is some doubt about the diagnosis, in order to exclude asthma. Inhaled corticosteroids and short-acting beta agonists may be used in the management of COPD for breathlessness/exercise limitation, but they are not used in the diagnosis of COPD. In summary, spirometry is the best diagnostic tool for COPD, and other diagnostic tools may have a role in the management of the condition.

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.

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.

Patient has exacerbation of COPD with maximal treatment for an hour. Remains acidotic with high PCO2 and respiratory acidosis. BTS guidelines suggest starting NIV.

Guidelines for Non-Invasive Ventilation in Acute Respiratory Failure

The British Thoracic Society (BTS) and the Royal College of Physicians have published guidelines for the use of non-invasive ventilation (NIV) in acute respiratory failure. NIV can be used in patients with COPD and respiratory acidosis with a pH of 7.25-7.35. However, patients with a pH lower than 7.25 require greater monitoring and a lower threshold for intubation and ventilation. NIV is also recommended for type II respiratory failure due to chest wall deformity, neuromuscular disease, or obstructive sleep apnea, as well as for cardiogenic pulmonary edema unresponsive to continuous positive airway pressure (CPAP) and weaning from tracheal intubation.

For patients with COPD, the recommended initial settings for bi-level pressure support include an expiratory positive airway pressure (EPAP) of 4-5 cm H2O, an inspiratory positive airway pressure (IPAP) of 10-15 cm H2O, a back-up rate of 15 breaths/min, and a back-up inspiration-to-expiration ratio of 1:3. These guidelines aim to improve patient outcomes and reduce the need for invasive mechanical ventilation.

Management of Acute Asthma

Acute asthma is classified by the British Thoracic Society (BTS) into three categories: moderate, severe, and life-threatening. Patients with any of the life-threatening features should be treated as having a life-threatening attack. A fourth category, Near-fatal asthma, is also recognized. Further assessment may include arterial blood gases for patients with oxygen saturation levels below 92%. A chest x-ray is not routinely recommended unless the patient has life-threatening asthma, suspected pneumothorax, or failure to respond to treatment.

Admission criteria include a previous near-fatal asthma attack, pregnancy, an attack occurring despite already using oral corticosteroid, and presentation at night. All patients with life-threatening asthma should be admitted to the hospital, and patients with features of severe acute asthma should also be admitted if they fail to respond to initial treatment. Oxygen therapy should be started for hypoxaemic patients. Bronchodilation with short-acting beta₂-agonists (SABA) is recommended, and all patients should be given 40-50mg of prednisolone orally daily. Ipratropium bromide and IV magnesium sulphate may also be considered for severe or life-threatening asthma. Patients who fail to respond require senior critical care support and should be treated in an appropriate ITU/HDU setting. Criteria for discharge include stability on discharge medication, checked and recorded inhaler technique, and PEF levels above 75% of best or predicted.

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.

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.

Different Types of Lung Diseases and their Spirometry Patterns

Scoliosis and Lung Function
Severe scoliosis can affect the respiratory muscles and the natural movements of the thoracic cage, leading to a restrictive pattern in pulmonary function tests. This can prevent the lungs from expanding correctly, compromising their function.

Cystic Fibrosis and Lung Function
In early stage cystic fibrosis, the presence of inflammation and thick secretions in the airways can cause an obstructive pattern in spirometry tests. As damage to the lung tissue occurs, a restrictive component can also develop, resulting in a combined obstructive and restrictive pattern.

Emphysema and Lung Function
Emphysema is a type of obstructive lung disease characterized by abnormal and irreversible enlargement of air spaces and alveolar wall destruction. This leads to airflow limitation and a spirometry pattern typical of obstructive lung disease.

Asthma and Lung Function
Asthma is an inflammatory disorder of the airways that causes hyperresponsiveness and constriction of the airways in response to various stimuli. This leads to airflow limitation and a spirometry pattern typical of obstructive lung disease.

Bronchiectasis and Lung Function
Bronchiectasis is characterized by abnormal and irreversible dilatation of the bronchial walls, leading to accumulation of secretions and recurrent inflammation of the airways. This produces an obstructive pattern in pulmonary function tests.

In summary, different types of lung diseases can affect lung function in various ways, leading to different spirometry patterns. Understanding these patterns can help in the diagnosis and management of these conditions.

Sarcoidosis is a condition where non-caseating granulomata develop in at least two organs, causing systemic inflammation. It is most common in African-Caribbean women and often affects the lungs, causing symptoms such as dry cough, dyspnea, and weight loss. Erythema nodosum is also frequently seen in patients with sarcoidosis. Histoplasmosis, Goodpasture’s syndrome, adenocarcinoma of the lung, and systemic lupus erythematosus are all possible differential diagnoses, but the absence of specific features makes sarcoidosis more likely in this case.

To manage symptoms in individuals with non-CF bronchiectasis, a combination of inspiratory muscle training and postural drainage can be effective.

Managing Bronchiectasis

Bronchiectasis is a condition where the airways become permanently dilated due to chronic inflammation or infection. Before starting treatment, it is important to identify any underlying causes that can be treated, such as immune deficiency. The management of bronchiectasis includes physical training, such as inspiratory muscle training, which has been shown to be effective for patients without cystic fibrosis. Postural drainage, antibiotics for exacerbations, and long-term rotating antibiotics for severe cases are also recommended. Bronchodilators may be used in selected cases, and immunizations are important to prevent infections. Surgery may be considered for localized disease. The most common organisms isolated from patients with bronchiectasis include Haemophilus influenzae, Pseudomonas aeruginosa, Klebsiella spp., and Streptococcus pneumoniae.

Spacing:

Bronchiectasis is a condition where the airways become permanently dilated due to chronic inflammation or infection. Before starting treatment, it is important to identify any underlying causes that can be treated, such as immune deficiency.

The management of bronchiectasis includes physical training, such as inspiratory muscle training, which has been shown to be effective for patients without cystic fibrosis. Postural drainage, antibiotics for exacerbations, and long-term rotating antibiotics for severe cases are also recommended. Bronchodilators may be used in selected cases, and immunizations are important to prevent infections. Surgery may be considered for localized disease.

The most common organisms isolated from patients with bronchiectasis include Haemophilus influenzae, Pseudomonas aeruginosa, Klebsiella spp., and Streptococcus pneumoniae.

Patients with COPD who have frequent exacerbations with sputum production, prolonged exacerbations with sputum production, or hospitalizations from exacerbations may be recommended prophylaxis with oral azithromycin if they are non-smokers and have optimized therapy. Before starting azithromycin, the patient should undergo CT thorax, ECG, liver function testing, and sputum cultures. Amoxicillin is not recommended for prophylaxis in COPD patients. Although doxycycline is one of the mainstay antibiotics used to treat acute exacerbations of COPD, it is not used in prophylactic management according to NICE guidelines. Ramipril is used in the management of pulmonary hypertension, which can occur secondary to COPD, but it is not indicated for a patient who experiences frequent exacerbations like the one in this vignette.

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.