The recommended daily oral dose for adults is 900 mg, which should be taken in 2-3 divided doses. For severe asthma or COPD, the initial intravenous dose is 5 mg/kg and should be administered over 10-20 minutes. This can be followed by a continuous infusion of 0.5 mg/kg/hour. In the case of a 60 kg patient, the appropriate infusion rate would be 30 mg/hour. It is important to note that the therapeutic range for aminophylline is narrow, ranging from 10-20 microgram/ml. Therefore, it is beneficial to estimate the plasma concentration of aminophylline during long-term treatment.

This patient is displaying symptoms and signs that are consistent with community-acquired pneumonia (CAP). The most common cause of CAP in an adult patient who is otherwise in good health is Streptococcus pneumoniae.

When it comes to treating community-acquired pneumonia, the first-line antibiotic of choice is amoxicillin. According to the NICE guidelines, patients who are allergic to penicillin should be prescribed a macrolide (such as clarithromycin) or a tetracycline (such as doxycycline).

For more information, you can refer to the NICE guidelines on the diagnosis and management of pneumonia in adults.

This patient exhibits signs of potentially life-threatening asthma. In adults, acute severe asthma is characterized by a peak expiratory flow (PEF) of 33-50% of the best or predicted value, a respiratory rate exceeding 25 breaths per minute, a heart rate over 110 beats per minute, and an inability to complete sentences in one breath. On the other hand, life-threatening asthma is indicated by a PEF below 33% of the best or predicted value, a blood oxygen saturation (SpO2) below 92%, a partial pressure of oxygen (PaO2) below 8 kPA, a normal partial pressure of carbon dioxide (PaCO2) within the range of 4.6-6.0 kPa, a silent chest, cyanosis, poor respiratory effort, exhaustion, altered consciousness, and hypotension.

To address acute asthma in adults, the recommended drug doses include administering 5 mg of salbutamol through an oxygen-driven nebulizer, delivering 500 mcg of ipratropium bromide via an oxygen-driven nebulizer, providing 40-50 mg of prednisolone orally, administering 100 mg of hydrocortisone intravenously, and infusing 1.2-2 g of magnesium sulfate intravenously over a period of 20 minutes.

According to the current Advanced Life Support (ALS) guidelines, it is advisable to seek senior advice before considering the use of intravenous aminophylline in cases of severe or life-threatening asthma. If used, a loading dose of 5 mg/kg should be given over 20 minutes, followed by a continuous infusion of 500-700 mcg/kg/hour. To prevent toxicity, it is important to maintain serum theophylline levels below 20 mcg/ml.

In situations where inhaled therapy is not feasible, intravenous salbutamol can be considered, with a slow administration of 250 mcg. However, it should only be used when a patient is receiving bag-mask ventilation.

It is worth noting that there is currently no evidence supporting the use of leukotriene receptor antagonists, such as montelukast, or Heliox in the management of acute severe or life-threatening asthma.

The recommended daily oral dose for adults is 900 mg, which should be taken in 2-3 divided doses. For severe asthma or COPD, the initial intravenous dose is 5 mg/kg and should be administered over 10-20 minutes. This can be followed by a continuous infusion of 0.5 mg/kg/hour. In the case of a patient weighing 60 kg, the appropriate loading dose would be 300 mg. It is important to note that the therapeutic range for aminophylline is narrow, ranging from 10-20 microgram/ml. Therefore, it is beneficial to estimate the plasma concentration of aminophylline during long-term treatment.

The clinical history and examination strongly suggest that the patient has a pulmonary embolism caused by a deep vein thrombosis in his right leg.

The typical symptoms of a pulmonary embolism include shortness of breath, chest pain that worsens with breathing, coughing, and/or coughing up blood. There may also be symptoms indicating the presence of a deep vein thrombosis. Other signs include rapid breathing and heart rate, fever, and in severe cases, signs of shock, an abnormal heart rhythm, and increased pressure in the jugular veins.

Given the patient’s high probability Wells score, it is recommended that an immediate CT pulmonary angiogram (CPTA) be performed. This test is considered the most reliable method for diagnosing a pulmonary embolism. A d-dimer test would not provide any additional benefit in this case. While a chest X-ray and ECG may provide useful information, they alone cannot confirm the diagnosis.

For patients who have an allergy to contrast media, renal impairment, or are at high risk from radiation exposure, a ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) scan or a V/Q planar scan can be offered as an alternative to CTPA.

In order to achieve satisfactory bronchodilation, most individuals require a plasma theophylline concentration of 10-20 mg/litre (55-110 micromol/litre). However, it is possible for a lower concentration to still be effective. Adverse effects can occur within the range of 10-20 mg/litre, and their frequency and severity increase when concentrations exceed 20 mg/litre.

To measure plasma theophylline concentration, a blood sample should be taken five days after starting oral treatment and at least three days after any dose adjustment. For modified-release preparations, the blood sample should typically be taken 4-6 hours after an oral dose (specific sampling times may vary, so it is advisable to consult local guidelines). If aminophylline is administered intravenously, a blood sample should be taken 4-6 hours after initiating treatment.

This question discusses the prioritization of patient care, specifically focusing on the initial management of acutely unwell patients. The sequence followed in such cases is known as ‘ABCDE’, which stands for airway, breathing, circulation, disability, and exposure. It is crucial to call for help as soon as possible, as the patient’s condition may deteriorate rapidly. If a patient’s consciousness level is dropping, urgent assistance is required, and it is unlikely that you will be able to handle the situation independently.

While waiting for the resuscitation team to arrive, you will be occupied with managing the patient. Therefore, it is not appropriate to make a phone call to the Emergency Department consultant for advice. Although the Emergency Department nurses may be helpful, it is essential to call the resuscitation team first. Continuing to handle the situation alone, regardless of the patient’s clinical condition, indicates a failure to recognize the need for assistance in this scenario.

Q fever is a highly contagious infection caused by Coxiella burnetii, which can be transmitted from animals to humans. It is commonly observed as an occupational disease among individuals working in farming, slaughterhouses, and animal research. Approximately 50% of cases do not show any symptoms, while those who are affected often experience flu-like symptoms such as headache, fever, muscle pain, diarrhea, nausea, and vomiting.

In some cases, patients may develop an atypical pneumonia characterized by a dry cough and minimal chest signs. Q fever can also lead to hepatitis and enlargement of the liver (hepatomegaly), although jaundice is not commonly observed. Typical blood test results for Q fever include an elevated white cell count (30-40%), ALT/AST levels that are usually 2-3 times higher than normal, increased ALP levels (70%), reduced sodium levels (30%), and reactive thrombocytosis.

It is important to check patients for heart murmurs and signs of valve disease, as these conditions increase the risk of developing infective endocarditis. Treatment for Q fever typically involves a two-week course of doxycycline.

This patient is displaying symptoms of life-threatening asthma, and the only available option for treatment with the correct dosage is an aminophylline loading dose.

The signs of acute severe asthma in adults include a peak expiratory flow (PEF) of 33-50% of the best or predicted value, a respiratory rate of over 25 breaths per minute, a heart rate of over 110 beats per minute, and an inability to complete sentences in one breath.

On the other hand, life-threatening asthma is characterized by a PEF of less than 33% of the best or predicted value, a blood oxygen saturation level (SpO2) below 92%, a partial pressure of oxygen (PaO2) below 8 kPA, a normal partial pressure of carbon dioxide (PaCO2) within the range of 4.6-6.0 kPa, a silent chest, cyanosis, poor respiratory effort, exhaustion, altered consciousness, and hypotension.

The recommended drug doses for adult acute asthma are as follows: 5 mg of salbutamol delivered through an oxygen-driven nebulizer, 500 mcg of ipratropium bromide via an oxygen-driven nebulizer, 40-50 mg of prednisolone taken orally, 100 mg of hydrocortisone administered intravenously, and 1.2-2 g of magnesium sulfate given intravenously over a period of 20 minutes. Intravenous salbutamol may be considered (250 mcg administered slowly) only when inhaled therapy is not possible, such as in a patient receiving bag-mask ventilation.

According to the current ALS guidelines, IV aminophylline can be considered in cases of severe or life-threatening asthma, following consultation with a senior medical professional. If used, a loading dose of 5 mg/kg should be administered over 20 minutes, followed by a continuous infusion of 500-700 mcg/kg/hour. It is important to maintain serum theophylline levels below 20 mcg/ml to prevent toxicity.

For more information, please refer to the BTS/SIGN Guideline on the Management of Asthma.

Ipratropium bromide is a medication that falls under the category of antimuscarinic drugs. It is commonly used to manage acute asthma and chronic obstructive pulmonary disease (COPD). While it can provide short-term relief for chronic asthma, it is generally recommended to use short-acting β2 agonists as they act more quickly and are preferred.

According to the guidelines set by the British Thoracic Society (BTS), nebulized ipratropium bromide (0.5 mg every 4-6 hours) can be added to β2 agonist treatment for patients with acute severe or life-threatening asthma, or those who do not respond well to initial β2 agonist therapy.

For mild cases of chronic obstructive pulmonary disease, aerosol inhalation of ipratropium can be used for short-term relief, as long as the patient is not already using a long-acting antimuscarinic drug like tiotropium. The maximum effect of ipratropium occurs within 30-60 minutes after use, and its bronchodilating effects can last for 3-6 hours. Typically, treatment with ipratropium is recommended three times a day to maintain bronchodilation.

The most common side effect of ipratropium bromide is dry mouth. Other potential side effects include constipation, cough, paroxysmal bronchospasm, headache, nausea, and palpitations. It is important to note that ipratropium can cause urinary retention in patients with prostatic hyperplasia and bladder outflow obstruction. Additionally, it can trigger acute closed-angle glaucoma in susceptible patients.

For more information on the management of asthma, it is recommended to refer to the BTS/SIGN Guideline on the Management of Asthma.

If a patient with breathing difficulty does not show improvement after removing the inner tracheostomy tube, it is recommended to use a suction catheter to remove any secretions. This can help clear any blockage caused by secretions or debris in or near the tube. If this does not improve the situation, the next step would be to deflate the cuff. If deflating the cuff stabilizes or improves the patient’s condition, it suggests that air can flow around the tube within the airway, indicating that the tracheostomy tube may be obstructed or displaced.

Further Reading:

Patients with tracheostomies may experience emergencies such as tube displacement, tube obstruction, and bleeding. Tube displacement can occur due to accidental dislodgement, migration, or erosion into tissues. Tube obstruction can be caused by secretions, lodged foreign bodies, or malfunctioning humidification devices. Bleeding from a tracheostomy can be classified as early or late, with causes including direct injury, anticoagulation, mucosal or tracheal injury, and granulation tissue.

When assessing a patient with a tracheostomy, an ABCDE approach should be used, with attention to red flags indicating a tracheostomy or laryngectomy emergency. These red flags include audible air leaks or bubbles of saliva indicating gas escaping past the cuff, grunting, snoring, stridor, difficulty breathing, accessory muscle use, tachypnea, hypoxia, visibly displaced tracheostomy tube, blood or blood-stained secretions around the tube, increased discomfort or pain, increased air required to keep the cuff inflated, tachycardia, hypotension or hypertension, decreased level of consciousness, and anxiety, restlessness, agitation, and confusion.

Algorithms are available for managing tracheostomy emergencies, including obstruction or displaced tube. Oxygen should be delivered to the face and stoma or tracheostomy tube if there is uncertainty about whether the patient has had a laryngectomy. Tracheostomy bleeding can be classified as early or late, with causes including direct injury, anticoagulation, mucosal or tracheal injury, and granulation tissue. Tracheo-innominate fistula (TIF) is a rare but life-threatening complication that occurs when the tracheostomy tube erodes into the innominate artery. Urgent surgical intervention is required for TIF, and management includes general resuscitation measures and specific measures such as bronchoscopy and applying direct digital pressure to the innominate artery.

One of the diagnostic criteria for ARDS is the presence of hypoxemia. Other criteria include the onset of symptoms within 7 days of a clinical insult or new/worsening respiratory symptoms, bilateral opacities on chest X-ray that cannot be fully explained by other conditions, and respiratory failure that cannot be fully attributed to cardiac failure or fluid overload.

Further Reading:

ARDS is a severe form of lung injury that occurs in patients with a predisposing risk factor. It is characterized by the onset of respiratory symptoms within 7 days of a known clinical insult, bilateral opacities on chest X-ray, and respiratory failure that cannot be fully explained by cardiac failure or fluid overload. Hypoxemia is also present, as indicated by a specific threshold of the PaO2/FiO2 ratio measured with a minimum requirement of positive end-expiratory pressure (PEEP) ≥5 cm H2O. The severity of ARDS is classified based on the PaO2/FiO2 ratio, with mild, moderate, and severe categories.

Lung protective ventilation is a set of measures aimed at reducing lung damage that may occur as a result of mechanical ventilation. Mechanical ventilation can cause lung damage through various mechanisms, including high air pressure exerted on lung tissues (barotrauma), over distending the lung (volutrauma), repeated opening and closing of lung units (atelectrauma), and the release of inflammatory mediators that can induce lung injury (biotrauma). These mechanisms collectively contribute to ventilator-induced lung injury (VILI).

The key components of lung protective ventilation include using low tidal volumes (5-8 ml/kg), maintaining inspiratory pressures (plateau pressure) below 30 cm of water, and allowing for permissible hypercapnia. However, there are some contraindications to lung protective ventilation, such as an unacceptable level of hypercapnia, acidosis, and hypoxemia. These factors need to be carefully considered when implementing lung protective ventilation strategies in patients with ARDS.

The recommended daily oral dose for adults is 900 mg, which should be taken in 2-3 divided doses. For severe asthma or COPD, the initial intravenous dose is 5 mg/kg and should be administered over 10-20 minutes. This can be followed by a continuous infusion of 0.5 mg/kg/hour. In the case of a 50 kg individual, the appropriate infusion rate would be 25 mg/hour. It is important to note that the therapeutic range for aminophylline is narrow, ranging from 10-20 microgram/ml. Therefore, it is beneficial to estimate the plasma concentration of aminophylline during long-term treatment.

The British Thoracic Society (BTS) advises that chest drains should be inserted within the safe triangle to minimize the risk of harm to underlying structures and prevent damage to muscle and breast tissue, which can result in unsightly scarring. The safe triangle is defined by the base of the axilla, the lateral border of the latissimus dorsi, the lateral border of the pectoralis major, and the 5th intercostal space.

There are several potential complications associated with the insertion of small-bore chest drains. These include puncture of the intercostal artery, accidental perforation of organs due to over-introduction of the dilator into the chest cavity, hospital-acquired pleural infection caused by a non-aseptic technique, inadequate stay suture that may lead to the chest tube falling out, and tube blockage, which may occur more frequently compared to larger bore Argyle drains.

For more information on this topic, please refer to the British Thoracic Society pleural disease guidelines.

The patient presents with a medical history and physical examination findings that are consistent with a diagnosis of Löfgren’s syndrome, which is a specific subtype of sarcoidosis. This syndrome is most commonly observed in women in their 30s and 40s, and it is more prevalent among individuals of Nordic and Irish descent.

Löfgren’s syndrome is typically characterized by a triad of clinical features, including bilateral hilar lymphadenopathy seen on chest X-ray, erythema nodosum, and arthralgia, with a particular emphasis on ankle involvement. Additionally, other symptoms commonly associated with sarcoidosis may also be present, such as a dry cough, breathlessness, fever, night sweats, malaise, weight loss, Achilles tendonitis, and uveitis.

In order to further evaluate this patient’s condition, it is recommended to refer them to a respiratory specialist for additional investigations. These investigations may include measuring the serum calcium level, as it may be elevated, and assessing the serum angiotensin-converting enzyme (ACE) level, which may also be elevated. A high-resolution CT scan can be performed to assess the extent of involvement and identify specific lymph nodes for potential biopsy. If there are any atypical features, a lymph node biopsy may be necessary. Lung function tests can be conducted to evaluate the patient’s vital capacity, and an MRI scan of the ankles may also be considered.

Fortunately, the prognosis for Löfgren’s syndrome is generally very good, and it is considered a self-limiting and benign condition. The patient can expect to recover within a timeframe of six months to two years.

This individual, who has been smoking for a long time, is likely to have squamous cell carcinoma of the lung located at the right apex. This particular type of cancer is causing Pancoast’s syndrome. Pancoast’s syndrome typically presents with rib erosion, leading to severe shoulder pain, as well as Horner’s syndrome due to the infiltration of the lower part of the brachial plexus. Additionally, there may be hoarseness of the voice and a ‘bovine cough’ due to a concurrent recurrent laryngeal nerve palsy.

The classic description of Horner’s syndrome includes the following clinical features on the same side as the tumor: miosis (constricted pupil), ptosis (drooping eyelid), anhidrosis (lack of sweating), and enophthalmos (sunken appearance of the eye). A chest X-ray would be able to detect the presence of the apical tumor and confirm the diagnosis.

Ipratropium bromide is a medication that falls under the category of antimuscarinic drugs. It is commonly used to manage acute asthma and chronic obstructive pulmonary disease (COPD). While it can provide short-term relief for chronic asthma, it is generally recommended to use short-acting β2 agonists as they act more quickly and are preferred.

According to the guidelines set by the British Thoracic Society (BTS), nebulized ipratropium bromide (0.5 mg every 4-6 hours) can be added to β2 agonist treatment for patients with acute severe or life-threatening asthma, or those who do not respond well to initial β2 agonist therapy.

For mild cases of chronic obstructive pulmonary disease, aerosol inhalation of ipratropium can be used for short-term relief, as long as the patient is not already using a long-acting antimuscarinic drug like tiotropium. The maximum effect of ipratropium occurs within 30-60 minutes after use, and its bronchodilating effects can last for 3-6 hours. Typically, treatment with ipratropium is recommended three times a day to maintain bronchodilation.

The most common side effect of ipratropium bromide is dry mouth. Other potential side effects include constipation, cough, paroxysmal bronchospasm, headache, nausea, and palpitations. It is important to note that ipratropium can cause urinary retention in patients with prostatic hyperplasia and bladder outflow obstruction. Additionally, it can trigger acute closed-angle glaucoma in susceptible patients.

For more information on the management of asthma, it is recommended to refer to the BTS/SIGN Guideline on the Management of Asthma.

Legionella pneumophila, a Gram-negative bacterium, can be found in natural water supplies and soil. It is responsible for causing Legionnaires’ disease, a serious illness. Outbreaks of this disease have been associated with poorly maintained air conditioning systems, whirlpool spas, and hot tubs.

The pneumonic form of Legionnaires’ disease presents with specific clinical features. Initially, there may be a mild flu-like prodrome lasting for 1-3 days. A non-productive cough, occurring in approximately 90% of cases, is also common. Pleuritic chest pain, haemoptysis, headache, nausea, vomiting, diarrhoea, and anorexia are other symptoms that may be experienced.

Fortunately, Legionella pneumophila infections can be effectively treated with macrolide antibiotics like erythromycin, or quinolones such as ciprofloxacin. Tetracyclines, including doxycycline, can also be used as a treatment option.

While the majority of Legionnaires’ disease cases are caused by Legionella pneumophila, there are several other species of Legionella that have been identified. One such species is Legionella longbeachae, which is less commonly encountered. It is primarily found in soil and potting compost and has been associated with outbreaks of Pontiac fever, a milder variant of Legionnaires’ disease that does not primarily affect the respiratory system.

The two-level PE Wells score has been simplified to determine the likelihood of a pulmonary embolism (PE) into two outcomes: likely or unlikely. A score of over 4 indicates that a PE is likely, while a score of 4 points or less indicates that a PE is unlikely.

The allocation of points is as follows:

– Clinical symptoms and signs of deep vein thrombosis (DVT) = 3 points
– An alternative diagnosis that is less likely than a PE = 3 points
– Heart rate greater than 100 = 1.5 points
– Immobilization for more than 3 days or recent surgery within 4 weeks = 1.5 points
– Previous history of DVT or PE = 1.5 points
– Presence of haemoptysis = 1 point
– Malignancy (currently on treatment, treated in the last 6 months, or palliative care) = 1 point.

The BTS guidelines for acute asthma in children recommend administering oral steroids early in the treatment of asthma attacks. It is advised to give a dose of 20 mg prednisolone for children aged 2–5 years and a dose of 30–40 mg for children over 5 years old. If a child is already taking maintenance steroid tablets, they should receive 2 mg/kg prednisolone, up to a maximum dose of 60 mg. If a child vomits after taking the medication, the dose of prednisolone should be repeated. In cases where a child is unable to keep down orally ingested medication, intravenous steroids should be considered. Typically, treatment for up to three days is sufficient, but the duration of the course should be adjusted based on the time needed for recovery. Tapering off the medication is not necessary unless the steroid course exceeds 14 days. For more information, refer to the BTS/SIGN Guideline on the Management of Asthma.

When rescuing drowning patients, it is important to extricate them from the water in a horizontal position whenever possible. This is because the pressure of the water on the body when submerged increases the flow of blood back to the heart, which in turn increases cardiac output. However, when the patient is removed from the water, this pressure effect is lost, which can lead to a sudden drop in blood pressure and circulatory collapse due to the loss of peripheral resistance and pooling of blood in the veins. By extricating the patient in a horizontal position, we can help counteract this effect.

It is worth noting that the amount of water in the lungs after drowning is typically small, usually less than 4 milliliters per kilogram of body weight. Therefore, attempting to drain the water from the lungs is ineffective and not recommended.

In cases of fresh water drowning, pneumonia may occur due to unusual pathogens such as aeromonas spp, burkholderia pseudomallei, chromobacterium spp, pseudomonas species, and leptospirosis.

If the patient experiences bronchospasm, nebulized bronchodilators can be used as a treatment.

To prevent secondary brain injury, it is important to prevent hyperthermia. This can be achieved by maintaining the patient’s core body temperature below 36 degrees Celsius during the rewarming process.

Further Reading:

Drowning is the process of experiencing respiratory impairment from submersion or immersion in liquid. It can be classified as cold-water or warm-water drowning. Risk factors for drowning include young age and male sex. Drowning impairs lung function and gas exchange, leading to hypoxemia and acidosis. It also causes cardiovascular instability, which contributes to metabolic acidosis and cell death.

When someone is submerged or immersed, they will voluntarily hold their breath to prevent aspiration of water. However, continued breath holding causes progressive hypoxia and hypercapnia, leading to acidosis. Eventually, the respiratory center sends signals to the respiratory muscles, forcing the individual to take an involuntary breath and allowing water to be aspirated into the lungs. Water entering the lungs stimulates a reflex laryngospasm that prevents further penetration of water. Aspirated water can cause significant hypoxia and damage to the alveoli, leading to acute respiratory distress syndrome (ARDS).

Complications of drowning include cardiac ischemia and infarction, infection with waterborne pathogens, hypothermia, neurological damage, rhabdomyolysis, acute tubular necrosis, and disseminated intravascular coagulation (DIC).

In children, the diving reflex helps reduce hypoxic injury during submersion. It causes apnea, bradycardia, and peripheral vasoconstriction, reducing cardiac output and myocardial oxygen demand while maintaining perfusion of the brain and vital organs.

Associated injuries with drowning include head and cervical spine injuries in patients rescued from shallow water. Investigations for drowning include arterial blood gases, chest X-ray, ECG and cardiac monitoring, core temperature measurement, and blood and sputum cultures if secondary infection is suspected.

Management of drowning involves extricating the patient from water in a horizontal position with spinal precautions if possible. Cardiovascular considerations should be taken into account when removing patients from water to prevent hypotension and circulatory collapse. Airway management, supplemental oxygen, and ventilation strategies are important in maintaining oxygenation and preventing further lung injury. Correcting hypotension, electrolyte disturbances, and hypothermia is also necessary. Attempting to drain water from the lungs is ineffective.

Patients without associated physical injury who are asymptomatic and have no evidence of respiratory compromise after six hours can be safely discharged home. Ventilation strategies aim to maintain oxygenation while minimizing ventilator-associated lung injury.

The BTS guidelines categorize acute asthma into four classifications: moderate, acute severe, life-threatening, and near-fatal.

Moderate asthma is characterized by increasing symptoms and a peak expiratory flow rate (PEFR) between 50-75% of the best or predicted value. There are no signs of acute severe asthma present in this classification.

Acute severe asthma is identified by any one of the following criteria: a PEFR between 33-50% of the best or predicted value, a respiratory rate exceeding 25 breaths per minute, a heart rate over 110 beats per minute, or the inability to complete sentences in one breath.

Life-threatening asthma is determined by any one of the following indicators: a PEFR below 33% of the best or predicted value, a blood oxygen saturation level (SpO2) below 92%, a partial pressure of oxygen (PaO2) below 8 kilopascals (kPa), a normal partial pressure of carbon dioxide (PaCO2) between 4.6-6.0 kPa, a silent chest, cyanosis, poor respiratory effort, arrhythmia, exhaustion, altered conscious level, or hypotension.

Near-fatal asthma is characterized by elevated PaCO2 levels and/or the need for mechanical ventilation with increased inflation pressures.

The diving reflex occurs when the face comes into contact with cold water, leading to apnoea, bradycardia, and peripheral vasoconstriction. This response helps decrease the workload on the heart, lower oxygen demand in the heart muscle, and ensure adequate blood flow to the brain and vital organs. The trigeminal nerve (CN V) is responsible for transmitting sensory information, while the vagus nerve (CN X) primarily controls the motor response. This reflex is more prominent in young children and is believed to contribute to their improved survival rates in prolonged submersion in cold water.

Further Reading:

Drowning is the process of experiencing respiratory impairment from submersion or immersion in liquid. It can be classified as cold-water or warm-water drowning. Risk factors for drowning include young age and male sex. Drowning impairs lung function and gas exchange, leading to hypoxemia and acidosis. It also causes cardiovascular instability, which contributes to metabolic acidosis and cell death.

When someone is submerged or immersed, they will voluntarily hold their breath to prevent aspiration of water. However, continued breath holding causes progressive hypoxia and hypercapnia, leading to acidosis. Eventually, the respiratory center sends signals to the respiratory muscles, forcing the individual to take an involuntary breath and allowing water to be aspirated into the lungs. Water entering the lungs stimulates a reflex laryngospasm that prevents further penetration of water. Aspirated water can cause significant hypoxia and damage to the alveoli, leading to acute respiratory distress syndrome (ARDS).

Complications of drowning include cardiac ischemia and infarction, infection with waterborne pathogens, hypothermia, neurological damage, rhabdomyolysis, acute tubular necrosis, and disseminated intravascular coagulation (DIC).

In children, the diving reflex helps reduce hypoxic injury during submersion. It causes apnea, bradycardia, and peripheral vasoconstriction, reducing cardiac output and myocardial oxygen demand while maintaining perfusion of the brain and vital organs.

Associated injuries with drowning include head and cervical spine injuries in patients rescued from shallow water. Investigations for drowning include arterial blood gases, chest X-ray, ECG and cardiac monitoring, core temperature measurement, and blood and sputum cultures if secondary infection is suspected.

Management of drowning involves extricating the patient from water in a horizontal position with spinal precautions if possible. Cardiovascular considerations should be taken into account when removing patients from water to prevent hypotension and circulatory collapse. Airway management, supplemental oxygen, and ventilation strategies are important in maintaining oxygenation and preventing further lung injury. Correcting hypotension, electrolyte disturbances, and hypothermia is also necessary. Attempting to drain water from the lungs is ineffective.

Patients without associated physical injury who are asymptomatic and have no evidence of respiratory compromise after six hours can be safely discharged home. Ventilation strategies aim to maintain oxygenation while minimizing ventilator-associated lung injury.

The typical pH range for blood is 7.35-7.45. The blood gases indicate a condition called respiratory acidosis, which is partially corrected by metabolic processes. This condition may also be referred to as type 2 respiratory failure, characterized by low oxygen levels and high carbon dioxide levels in the blood.

Further Reading:

Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.

To reduce the risk of harm to the patient, it is important to test for collateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.

Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.

The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.

The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.

The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.

Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.

The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.

The BTS guidelines for managing acute asthma in children over the age of 2 recommend the following approaches:

Bronchodilator therapy is the first-line treatment for acute asthma. Inhaled β agonists are preferred, and a pmDI + spacer is the recommended option for children with mild to moderate asthma. It is important to individualize drug dosing based on the severity of the condition and adjust it according to the patient’s response. If initial β agonist treatment does not alleviate symptoms, ipratropium bromide can be added to the nebulized β2 agonist solution. In cases where children with a short duration of acute severe asthma symptoms have an oxygen saturation level below 92%, it is advisable to consider adding 150 mg of magnesium sulfate to each nebulized salbutamol and ipratropium within the first hour.

Long-acting β2 agonists should be discontinued if short-acting β2 agonists are required more frequently than every four hours.

Steroid therapy should be initiated early in the treatment of acute asthma attacks. For children aged 2-5 years, a dose of 20 mg prednisolone is recommended, while children over the age of 5 should receive a dose of 30-40 mg. Children already on maintenance steroid tablets should receive 2 mg/kg prednisolone, up to a maximum dose of 60 mg. If a child vomits after taking the initial dose of prednisolone, the dose should be repeated. In cases where a child is unable to retain orally ingested medication, intravenous steroids should be considered. Typically, treatment with oral steroids for up to three days is sufficient, but the duration of the course should be adjusted based on the time needed for recovery. Tapering is not necessary unless the course of steroids exceeds 14 days.

In cases where initial inhaled therapy does not yield a response in severe asthma attacks, the early addition of a single bolus dose of intravenous salbutamol (15 micrograms/kg over 10 minutes) should be considered. Aminophylline is not recommended for children with mild to moderate acute asthma, but it may be considered for those with severe or life-threatening asthma that is unresponsive to maximum doses of bronchodilators and steroids. The use of IV magnesium sulfate as a treatment for acute asthma in children is considered safe, although its role in management is not yet fully established.

Bronchiolitis is a respiratory infection that primarily affects infants aged 2 to 6 months. It is typically caused by a viral infection, with respiratory syncytial virus (RSV) being the most common culprit. RSV infections are most prevalent during the winter months, from November to March. In fact, bronchiolitis is the leading cause of hospitalization among infants in the UK.

The symptoms of bronchiolitis include poor feeding (consuming less than 50% of their usual intake in the past 24 hours), lethargy, a history of apnea, a respiratory rate exceeding 70 breaths per minute, nasal flaring or grunting, severe chest wall recession, cyanosis (bluish discoloration of the skin), and low oxygen saturation levels. For children aged 6 weeks and older, oxygen saturation levels below 90% indicate a need for medical attention. For babies under 6 weeks or those with underlying health conditions, oxygen saturation levels below 92% require medical attention.

To confirm the diagnosis of bronchiolitis, a nasopharyngeal aspirate can be taken for rapid testing of RSV. This test is useful in preventing unnecessary further testing and allows for the isolation of the infected infant.

Most infants with bronchiolitis experience a mild, self-limiting illness that does not require hospitalization. Treatment primarily focuses on supportive measures, such as ensuring adequate fluid and nutritional intake and controlling the infant’s temperature. The illness typically lasts for 7 to 10 days.

However, hospital referral and admission are recommended in cases of poor feeding, lethargy, a history of apnea, a respiratory rate exceeding 70 breaths per minute, nasal flaring or grunting, severe chest wall recession, cyanosis, and oxygen saturation levels below 94%. If hospitalization is necessary, treatment involves supportive measures, supplemental oxygen, and nasogastric feeding as needed. There is limited or no evidence supporting the use of antibiotics, antivirals, bronchodilators, corticosteroids, hypertonic saline, or adrenaline nebulizers for the treatment of bronchiolitis.

The BTS guidelines for acute asthma in children recommend administering oral steroids early in the treatment of asthma attacks. It is advised to give a dose of 20 mg prednisolone for children aged 2–5 years and a dose of 30–40 mg for children over 5 years old. If a child is already taking maintenance steroid tablets, they should receive 2 mg/kg prednisolone, up to a maximum dose of 60 mg. If a child vomits after taking the medication, the dose of prednisolone should be repeated. In cases where a child is unable to keep down orally ingested medication, intravenous steroids should be considered. Typically, treatment for up to three days is sufficient, but the duration of the course should be adjusted based on the time needed for recovery. Tapering off the medication is not necessary unless the steroid course exceeds 14 days. For more information, refer to the BTS/SIGN Guideline on the Management of Asthma.

The guidelines from the British Thoracic Society (BTS) recommend conducting investigations for Legionella infection in the following cases: severe community-acquired pneumonia, patients with specific risk factors, and during outbreaks of community-acquired pneumonia. To confirm a case, the Public Health England (PHE) requires one of the following: isolation and culture of Legionella species from clinical specimens (typically sputum), seroconversion with a four-fold increase in titre of indirect immunofluorescent antibody test (IFAT) using a validated technique, or confirmation of Legionella pneumophila urinary antigen using validated reagents or kits. The gold standard for confirmation is the isolation and culture of Legionella species, while cases of Pontiac fever are usually culture-negative. The HPA considers a case presumptive if there is a clinical diagnosis of pneumonia with a single high titre of 128 using IFAT, or a single titre of 64 in an outbreak. A positive result by direct immunofluorescence on a clinical specimen using validated monoclonal antibodies is also considered a presumptive case.

This individual has presented with an episode of acute asthma. Their PaCO2 levels are elevated at 6.3 kPa, indicating a near-fatal exacerbation. According to the BTS guidelines, acute asthma can be classified as moderate, acute severe, life-threatening, or near-fatal.

Moderate asthma is characterized by increasing symptoms and a PEFR (peak expiratory flow rate) of 50-75% of the best or predicted value. There are no features of acute severe asthma present in this classification.

Acute severe asthma can be identified by any one of the following criteria: a PEFR of 33-50% of the best or predicted value, a respiratory rate exceeding 25 breaths per minute, a heart rate surpassing 110 beats per minute, or the inability to complete sentences in one breath.

Life-threatening asthma is determined by any one of the following indicators: a PEFR below 33% of the best or predicted value, an SpO2 (oxygen saturation) level below 92%, a PaO2 (partial pressure of oxygen) below 8 kPa, normal PaCO2 levels (ranging from 4.6-6.0 kPa), a silent chest, cyanosis, poor respiratory effort, arrhythmia, exhaustion, altered conscious level, or hypotension.

Near-fatal asthma is characterized by a raised PaCO2 level and/or the need for mechanical ventilation with elevated inflation pressures.

Bronchiolitis is a common respiratory infection that primarily affects infants. It typically occurs between the ages of 3-6 months and is most prevalent during the winter months from November to March. The main culprit behind bronchiolitis is the respiratory syncytial virus, accounting for about 70% of cases. However, other viruses like parainfluenza, influenza, adenovirus, coronavirus, and rhinovirus can also cause this infection.

The clinical presentation of bronchiolitis usually starts with symptoms resembling a common cold, which last for the first 2-3 days. Infants may experience poor feeding, rapid breathing (tachypnoea), nasal flaring, and grunting. Chest wall recessions, bilateral fine crepitations, and wheezing may also be observed. In severe cases, apnoea, a temporary cessation of breathing, can occur.

Bronchiolitis is a self-limiting illness, meaning it resolves on its own over time. Therefore, treatment mainly focuses on supportive care. However, infants with oxygen saturations below 92% may require oxygen administration. If an infant is unable to maintain oral intake or hydration, nasogastric feeding should be considered. Nasal suction is recommended to clear secretions in infants experiencing respiratory distress due to nasal blockage.

It is important to note that there is no evidence supporting the use of antivirals (such as ribavirin), antibiotics, beta 2 agonists, anticholinergics, or corticosteroids in the management of bronchiolitis. These interventions are not recommended for this condition.