Enterovirus Meningitis: The Commonest Cause of Viral Meningitis in Adults

Enterovirus meningitis is the most common cause of viral meningitis in adults. The symptoms of a mild diarrhoeal illness and a runny nose, along with the lumbar puncture findings, are consistent with this diagnosis. The management of viral meningitis is conservative, with adequate hydration and analgesia.

Understanding Hepatitis A: Symptoms, Transmission, and Prevention

Hepatitis A is a viral infection caused by the RNA picornavirus. It is typically spread through faecal-oral transmission, often in institutions. The incubation period is around 2-4 weeks, and symptoms include a flu-like prodrome, abdominal pain (usually in the right upper quadrant), tender hepatomegaly, jaundice, and deranged liver function tests. However, the disease is usually self-limiting and benign, with serious complications being rare.

Unlike other forms of hepatitis, hepatitis A does not cause chronic disease or increase the risk of hepatocellular cancer. An effective vaccine is available, and it is recommended for people who are travelling to or residing in areas of high or intermediate prevalence, those with chronic liver disease, patients with haemophilia, men who have sex with men, injecting drug users, and individuals at occupational risk (such as laboratory workers, staff of large residential institutions, sewage workers, and people who work with primates). After the initial dose, a booster dose should be given 6-12 months later.

Understanding the symptoms, transmission, and prevention of hepatitis A is important for individuals who may be at risk of contracting the virus. By taking appropriate precautions and getting vaccinated, individuals can protect themselves and others from this viral infection.

To determine the cause of a pleural effusion, the effusion fluid protein/serum protein ratio can be used. An effusion is considered exudative if the ratio is >0.5, indicating that there is more protein in the effusion than in the serum. In this patient’s case, the ratio is 0.73, indicating an exudative effusion. Only one of the listed options can cause an exudative effusion.

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 posterior anterior (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.

Gallstones: Symptoms, Diagnosis, and Treatment

Gallstones are a common condition, with up to 24% of women and 12% of men affected. Local infection and cholecystitis may develop in up to 30% of cases, and 12% of patients undergoing surgery will have stones in the common bile duct. The majority of gallstones are of mixed composition, with pure cholesterol stones accounting for 20% of cases. Symptoms typically include colicky right upper quadrant pain that worsens after fatty meals. Diagnosis involves abdominal ultrasound and liver function tests, with magnetic resonance cholangiography or intraoperative imaging used to confirm the presence of stones in the bile duct. Treatment options include expectant management for asymptomatic gallstones, laparoscopic cholecystectomy for symptomatic gallstones, and early ERCP or surgical exploration for stones in the bile duct. Intraoperative cholangiography or laparoscopic ultrasound may be used to confirm anatomy or exclude CBD stones during surgery. ERCP carries risks such as bleeding, duodenal perforation, cholangitis, and pancreatitis.

Donepezil is classified as an acetylcholinesterase inhibitor and is considered a first-line treatment option for managing mild to moderate Alzheimer’s dementia, along with galantamine and rivastigmine. Memantine, on the other hand, is an NMDA receptor antagonist and is typically used as a second-line or adjunctive treatment for mild to moderate Alzheimer’s dementia, although it may be used as a first-line option for severe cases. Oxybutynin and tolterodine are anti-muscarinic medications that are commonly prescribed for urge incontinence, but immediate release oxybutynin should be avoided in frail older women, according to NICE guidelines. Finally, rotigotine is a dopamine agonist that is used to treat Parkinson’s disease and restless legs syndrome.

Managing Alzheimer’s Disease: Non-Pharmacological and Pharmacological Approaches

Alzheimer’s disease is a type of dementia that progressively affects the brain and is the most common form of dementia in the UK. To manage this condition, there are both non-pharmacological and pharmacological approaches available.

Non-pharmacological management involves offering a range of activities that promote wellbeing and are tailored to the patient’s preferences. Group cognitive stimulation therapy is recommended for patients with mild to moderate dementia, while group reminiscence therapy and cognitive rehabilitation are also options to consider.

Pharmacological management involves the use of medications. The three acetylcholinesterase inhibitors (donepezil, galantamine, and rivastigmine) are options for managing mild to moderate Alzheimer’s disease. Memantine, an NMDA receptor antagonist, is considered a second-line treatment and is recommended for patients with moderate Alzheimer’s who are intolerant of or have a contraindication to acetylcholinesterase inhibitors. It can also be used as an add-on drug to acetylcholinesterase inhibitors for patients with moderate or severe Alzheimer’s or as monotherapy in severe Alzheimer’s.

When managing non-cognitive symptoms, NICE does not recommend antidepressants for mild to moderate depression in patients with dementia. Antipsychotics should only be used for patients at risk of harming themselves or others or when the agitation, hallucinations, or delusions are causing them severe distress.

It is important to note that donepezil is relatively contraindicated in patients with bradycardia, and adverse effects may include insomnia. By utilizing both non-pharmacological and pharmacological approaches, patients with Alzheimer’s disease can receive comprehensive care and management.

The recommended course of action is to order a combination test for HIV p24 antigen and HIV antibody. The patient is exhibiting symptoms of HIV seroconversion and had unprotected intercourse 4 weeks ago. Combination tests are now the standard for HIV diagnosis and screening, with p24 antigen tests typically turning positive between 1 and 4 weeks post-exposure and antibody tests turning positive between 4 weeks and 3 months post-exposure. If a patient at risk tests positive, the diagnosis should be confirmed with a repeat test before starting treatment.

Offering post-exposure prophylaxis is not appropriate in this case, as the patient had unprotected intercourse 3 weeks ago. Two NRTIs and an NNRTI should not be prescribed as treatment, as the patient has not yet tested positive. Ordering only a p24 antigen or antibody test alone is also not recommended, as combination tests are now standard practice.

Understanding HIV Seroconversion and Diagnosis

HIV seroconversion is a process where the body develops antibodies to the HIV virus after being infected. This process is symptomatic in 60-80% of patients and usually presents as a glandular fever type illness. Symptoms may include sore throat, lymphadenopathy, malaise, myalgia, arthralgia, diarrhea, maculopapular rash, mouth ulcers, and rarely meningoencephalitis. The severity of symptoms is associated with a poorer long-term prognosis and typically occurs 3-12 weeks after infection.

Diagnosing HIV involves testing for HIV antibodies, which may not be present in early infection. However, most people develop antibodies to HIV at 4-6 weeks, and 99% do so by 3 months. The diagnosis usually consists of both a screening ELISA test and a confirmatory Western Blot Assay. Additionally, a p24 antigen test may be used to detect a viral core protein that appears early in the blood as the viral RNA levels rise. Combination tests that test for both HIV p24 antigen and HIV antibody are now standard for the diagnosis and screening of HIV. If the combined test is positive, it should be repeated to confirm the diagnosis. Testing for HIV in asymptomatic patients should be done at 4 weeks after possible exposure, and after an initial negative result, a repeat test should be offered at 12 weeks.

Chlamydia trachomatis infection is a common cause of non-specific urethritis, which presents with dysuria and urethral discharge.

The most probable diagnosis in this case is chlamydia, which may also be accompanied by gonorrhea infection. Nucleic acid amplification tests (NAAT) are used to diagnose chlamydia, and both urethral swab and first-catch urine samples can be used for this purpose. However, first-catch urine is preferred as it is less invasive and equally sensitive as a urethral swab.

While midstream urinalysis is appropriate for diagnosing urinary tract infections, the absence of haematuria or abdominal pain and the presence of urethral discharge make it less likely than chlamydia infection. Collecting discharge for microscopy and culture may be helpful in diagnosing bacterial vaginosis.

Full blood count and liver function tests are not useful in diagnosing chlamydia. However, in female patients with advanced chlamydia who have developed pelvic inflammatory disease, these tests may be crucial in diagnosing Fitz Hugh Curtis syndrome.

Understanding Urethritis in Men

Urethritis is a condition that primarily affects men and is characterized by dysuria and/or urethral discharge. However, it can also be asymptomatic in some cases. The condition is traditionally divided into two types: gonococcal and non-gonococcal urethritis (NGU), which is now referred to as non-specific urethritis (NSU). The most common causes of NSU are Chlamydia trachomatis, Ureaplasma urealyticum, and Mycoplasma genitalium.

To diagnose NSU, a urethral swab is taken and Gram stained to check for the presence of leukocytes and Gram-negative diplococci. Chlamydia is now increasingly diagnosed using urinary nucleic acid amplification tests. If left untreated, NSU can lead to complications such as epididymitis, subfertility, and reactive arthritis.

The management of NSU involves either a seven-day course of oral doxycycline or a single dose of oral azithromycin.

For patients under 65 years old with subclinical hypothyroidism and a TSH level between 5.5-10mU/L, a 6-month trial of thyroxine should be offered if they have hypothyroidism symptoms and their TSH remains elevated on two separate occasions 3 months apart. This is because subclinical hypothyroidism increases the risk of cardiovascular disease and progression to overt hypothyroidism, and treatment with levothyroxine generally resolves symptoms. Repeat thyroid autoantibody tests and thyroid function testing after 3 months are unnecessary if the patient has already had negative autoantibody results and two elevated TSH levels 3 months apart. Prescribing levothyroxine only if further symptoms develop is not recommended as it delays treatment and increases the risk of negative impacts on the patient’s quality of life.

Understanding Subclinical Hypothyroidism

Subclinical hypothyroidism is a condition where the thyroid-stimulating hormone (TSH) is elevated, but the levels of T3 and T4 are normal, and there are no obvious symptoms. However, there is a risk of the condition progressing to overt hypothyroidism, especially in men, with a 2-5% chance per year. This risk is further increased if thyroid autoantibodies are present.

Not all patients with subclinical hypothyroidism require treatment, and guidelines have been produced by NICE Clinical Knowledge Summaries (CKS) to help determine when treatment is necessary. If the TSH level is above 10mU/L and the free thyroxine level is within the normal range, levothyroxine may be offered. If the TSH level is between 5.5 – 10mU/L and the free thyroxine level is within the normal range, a 6-month trial of levothyroxine may be considered if the patient is under 65 years old and experiencing symptoms of hypothyroidism. For older patients, a ‘watch and wait’ strategy is often used, and asymptomatic patients may simply have their thyroid function monitored every 6 months.

In summary, subclinical hypothyroidism is a condition that requires careful monitoring and consideration of treatment options based on individual patient factors.

If a patient with distal ulcerative colitis experiences a mild-moderate flare that does not respond to topical aminosalicylates, oral aminosalicylates should be added as an adjunct therapy. In this case, the patient’s symptoms are typical of a mild flare according to Truelove and Witt’s criteria. As his symptoms are not improving with topical treatment, oral mesalazine should be added while continuing the topical mesalazine. Oral steroids are not currently indicated for this patient’s mild flare. It is important to continue the topical therapy alongside the oral therapy for optimal management. If symptoms do not improve within two weeks, the patient should schedule a follow-up appointment.

Ulcerative colitis can be managed through inducing and maintaining remission. The severity of the condition is classified as mild, moderate, or severe based on the number of stools and presence of systemic upset. Treatment for mild-to-moderate cases of proctitis involves using topical aminosalicylate, while proctosigmoiditis and left-sided ulcerative colitis may require a combination of oral and topical medications. Extensive disease may require a high-dose oral aminosalicylate and topical treatment. Severe colitis should be treated in a hospital with intravenous steroids or ciclosporin. Maintaining remission can involve using a low maintenance dose of an oral aminosalicylate or oral azathioprine/mercaptopurine. Methotrexate is not recommended, but probiotics may prevent relapse in mild to moderate cases.

Possible Diagnosis for a Man with Chronic Alcohol Abuse

This man, who has a history of chronic alcohol abuse, is exhibiting symptoms of a fever and left-sided hemiparesis. The most probable diagnosis for this individual would be cerebral abscess. It is unlikely that a subdural hematoma or a simple cerebrovascular accident (CVA) would explain the fever, nor would they be associated with hemiparesis. Delirium tremens or encephalopathy would not be linked to the hemiparesis either. Therefore, cerebral abscess is the most likely diagnosis for this man with chronic alcohol abuse who is experiencing a fever and left-sided hemiparesis.

When a patient presents with new-onset atrial fibrillation (AF), the management plan depends on the duration and recurrence of symptoms, as well as risk stratification. If symptoms have been present for less than 48 hours, electrical cardioversion is recommended, but anticoagulation should be started beforehand. Heparin is a good choice for rapid onset anticoagulation. However, if symptoms have been present for more than 48 hours, there is a higher risk of atrial thrombus, which may cause thromboembolic disease. In this case, a transoesophageal echocardiogram (TOE) should be obtained to exclude a thrombus before cardioversion, or anticoagulation should be started for 3 weeks prior to cardioversion. Amiodarone oral therapy is not adequate for cardioversion in acute AF. If cardioversion is not possible, a DOAC such as apixaban or rivaroxaban should be started. Discharge home is appropriate for patients with chronic AF or after cardioversion. While pharmacological cardioversion with intravenous amiodarone is an option, electrical cardioversion is preferred according to NICE guidelines, especially in patients with structural heart disease.

Atrial Fibrillation and Cardioversion: Elective Procedure for Rhythm Control

Cardioversion is a medical procedure used in atrial fibrillation (AF) to restore the heart’s normal rhythm. There are two scenarios where cardioversion may be used: as an emergency if the patient is haemodynamically unstable, or as an elective procedure where a rhythm control strategy is preferred. In the elective scenario, cardioversion can be performed either electrically or pharmacologically. Electrical cardioversion is synchronised to the R wave to prevent delivery of a shock during the vulnerable period of cardiac repolarisation when ventricular fibrillation can be induced.

According to the 2014 NICE guidelines, rate or rhythm control should be offered if the onset of the arrhythmia is less than 48 hours, and rate control should be started if it is more than 48 hours or is uncertain. If the AF is definitely of less than 48 hours onset, patients should be heparinised and may be cardioverted using either electrical or pharmacological means. However, if the patient has been in AF for more than 48 hours, anticoagulation should be given for at least 3 weeks prior to cardioversion. An alternative strategy is to perform a transoesophageal echo (TOE) to exclude a left atrial appendage (LAA) thrombus. If excluded, patients may be heparinised and cardioverted immediately.

NICE recommends electrical cardioversion in this scenario, rather than pharmacological. If there is a high risk of cardioversion failure, it is recommended to have at least 4 weeks of amiodarone or sotalol prior to electrical cardioversion. Following electrical cardioversion, patients should be anticoagulated for at least 4 weeks. After this time, decisions about anticoagulation should be taken on an individual basis depending on the risk of recurrence.

Controlled hyperventilation can be employed for patients with elevated ICP by increasing CO2 expiration. This leads to constriction of cerebral arteries due to low blood CO2 levels. As a result, blood flow decreases, reducing the volume inside the cranium and ultimately lowering intracranial pressure. Therefore, the other options are incorrect.

Understanding Raised Intracranial Pressure

As the brain and ventricles are enclosed by a rigid skull, any additional volume such as haematoma, tumour, or excessive cerebrospinal fluid (CSF) can lead to a rise in intracranial pressure (ICP). In adults, the normal ICP is between 7-15 mmHg in the supine position. The net pressure gradient causing cerebral blood flow to the brain is known as cerebral perfusion pressure (CPP), which can be calculated by subtracting ICP from mean arterial pressure.

Raised intracranial pressure can be caused by various factors such as idiopathic intracranial hypertension, traumatic head injuries, infections, meningitis, tumours, and hydrocephalus. Its symptoms include headache, vomiting, reduced levels of consciousness, papilloedema, and Cushing’s triad, which is characterized by widening pulse pressure, bradycardia, and irregular breathing.

To investigate the underlying cause, neuroimaging such as CT or MRI is key. Invasive ICP monitoring can also be done by placing a catheter into the lateral ventricles of the brain to monitor the pressure, collect CSF samples, and drain small amounts of CSF to reduce the pressure. A cut-off of >20 mmHg is often used to determine if further treatment is needed to reduce the ICP.

Management of raised intracranial pressure involves investigating and treating the underlying cause, head elevation to 30º, IV mannitol as an osmotic diuretic, controlled hyperventilation to reduce pCO2 and vasoconstriction of the cerebral arteries, and removal of CSF through techniques such as drain from intraventricular monitor, repeated lumbar puncture, or ventriculoperitoneal shunt for hydrocephalus.

Weber’s syndrome is a type of midbrain stroke that causes ipsilateral CN III palsy and contralateral hemiparesis. It is caused by a blockage in the branches of the posterior cerebral artery that supply the midbrain. Anterior cerebral artery strokes cause contralateral lower limb weakness, while basilar artery strokes cause bilateral paralysis and locked-in syndrome.

When a stroke occurs, the location of the lesion in the brain can determine the specific effects on the body. Depending on which artery is affected, different symptoms may arise. For example, a stroke in the anterior cerebral artery can lead to contralateral hemiparesis and sensory loss, with the lower extremity being more affected than the upper. On the other hand, a stroke in the middle cerebral artery can cause contralateral hemiparesis and sensory loss, with the upper extremity being more affected than the lower, as well as contralateral homonymous hemianopia and aphasia.

If the stroke occurs in the posterior cerebral artery, the individual may experience contralateral homonymous hemianopia with macular sparing and visual agnosia. In the case of Weber’s syndrome, which involves branches of the posterior cerebral artery that supply the midbrain, the person may have an ipsilateral CN III palsy and contralateral weakness of the upper and lower extremities.

Other types of strokes include those affecting the posterior inferior cerebellar artery, which can lead to ipsilateral facial pain and temperature loss and contralateral limb/torso pain and temperature loss, as well as ataxia and nystagmus. A stroke in the anterior inferior cerebellar artery can cause similar symptoms to Wallenberg’s syndrome, but with the addition of ipsilateral facial paralysis and deafness.

Finally, lacunar strokes are small, localized strokes that often occur in individuals with hypertension. They typically present with isolated hemiparesis, hemisensory loss, or hemiparesis with limb ataxia, and commonly affect the basal ganglia, thalamus, and internal capsule.

Patients who exhibit signs of shock and bradycardia should be administered 500 micrograms of atropine, which can be repeated up to a maximum of 3mg. In the case of this patient, who has experienced syncope and is unstable, atropine is necessary. Amiodarone is used for tachycardias, while bisoprolol is used for rate control in longstanding tachycardias. DC cardioversion is used for tachycardia, and if atropine is ineffective, transcutaneous pacing may be considered. IV saline would not be beneficial in this case, as the patient’s hypotension is caused by bradycardia rather than hypovolemia.

Management of Bradycardia in Peri-Arrest Rhythms

The 2021 Resuscitation Council (UK) guidelines highlight that the management of bradycardia in peri-arrest rhythms depends on two factors. Firstly, identifying adverse signs that indicate haemodynamic compromise, such as shock, syncope, myocardial ischaemia, or heart failure. Secondly, identifying the potential risk of asystole, which can occur in patients with complete heart block with broad complex QRS, recent asystole, Mobitz type II AV block, or ventricular pause > 3 seconds.

If adverse signs are present, Atropine (500mcg IV) is the first line treatment. If there is an unsatisfactory response, interventions such as atropine (up to a maximum of 3mg), transcutaneous pacing, or isoprenaline/adrenaline infusion titrated to response may be used. Specialist help should be sought for consideration of transvenous pacing if there is no response to the above measures.

Even if there is a satisfactory response to atropine, specialist help is indicated to consider the need for transvenous pacing in patients with risk factors for asystole. By following these guidelines, healthcare professionals can effectively manage bradycardia in peri-arrest rhythms and improve patient outcomes.

The patient has type 2 diabetes, coronary artery disease, and stage 3 chronic kidney disease, putting him at risk for cardiovascular events and renal function decline. Ramipril 10 mg is recommended to improve blood pressure control and preserve kidney function. Stopping smoking and using simvastatin are essential for cardiac risk management. HbA1c is reasonable at 51 mmol/mol.

In haemolytic uraemic syndrome, there is a reduction in serum haptoglobins, which bind to haemoglobin, and the platelet count.

Understanding Haemolytic Uraemic Syndrome

Haemolytic uraemic syndrome (HUS) is a condition that primarily affects young children and is characterized by a triad of symptoms, including acute kidney injury, microangiopathic haemolytic anaemia, and thrombocytopenia. The majority of cases are secondary and caused by Shiga toxin-producing Escherichia coli (STEC) 0157:H7, also known as ‘verotoxigenic’ or ‘enterohaemorrhagic’. Other causes of HUS include pneumococcal infection, HIV, systemic lupus erythematosus, drugs, and cancer. Primary HUS, also known as ‘atypical’, is caused by complement dysregulation.

To diagnose HUS, doctors may perform a full blood count to check for microangiopathic hemolytic anaemia and thrombocytopenia. A fragmented blood film may also be done to look for schistocytes and helmet cells. Additionally, a stool culture may be performed to check for evidence of STEC infection, and PCR for Shiga toxins may be done.

Treatment for HUS is supportive and may include fluids, blood transfusion, and dialysis if required. Antibiotics are not recommended, despite the preceding diarrhoeal illness in many patients. Plasma exchange may be considered for severe cases of HUS not associated with diarrhoea, while eculizumab, a C5 inhibitor monoclonal antibody, has shown greater efficiency than plasma exchange alone in the treatment of adult atypical HUS.

Overall, understanding the causes, symptoms, and management of HUS is crucial for healthcare professionals to provide appropriate care for patients with this condition.

For a patient with a history of COPD, a pneumothorax is classified as secondary. If the pneumothorax is greater than 2 cm or the patient is experiencing shortness of breath, the recommended first-line treatment is a chest drain, not aspiration. However, if the pneumothorax is primary and greater than 2 cm or the patient is breathless, or if the secondary pneumothorax is between 1-2 cm, needle aspiration may be indicated. If a patient is admitted for observation, they may receive high flow oxygen unless they are oxygen sensitive. Admission for observation is recommended for a secondary pneumothorax measuring less than 1 cm or a secondary pneumothorax measuring 1-2 cm that is aspirated and subsequently measures less than 1 cm. A primary pneumothorax measuring less than 2 cm may be considered for discharge.

Management of Pneumothorax: BTS Guidelines

Pneumothorax is a condition where air accumulates in the pleural space, causing the lung to collapse. The British Thoracic Society (BTS) has published updated guidelines for the management of spontaneous pneumothorax, which can be primary or secondary. Primary pneumothorax occurs without any underlying lung disease, while secondary pneumothorax is associated with lung disease.

The BTS guidelines recommend that patients with a rim of air less than 2 cm and no shortness of breath may be discharged, while those with a larger rim of air or shortness of breath should undergo aspiration or chest drain insertion. For secondary pneumothorax, patients over 50 years old with a rim of air greater than 2 cm or shortness of breath should undergo chest drain insertion. Aspiration may be attempted for those with a rim of air between 1-2 cm, but chest drain insertion is necessary if aspiration fails.

For iatrogenic pneumothorax, observation is usually sufficient, but chest drain insertion may be necessary in some cases. Ventilated patients and those with chronic obstructive pulmonary disease (COPD) may require chest drain insertion. If a patient has persistent or recurrent pneumothorax, video-assisted thoracoscopic surgery (VATS) may be necessary.

Patients should be advised to avoid smoking to reduce the risk of further episodes. Fitness to fly is an absolute contraindication, but patients may travel 1 week after successful drainage if there is no residual air. Scuba diving should be permanently avoided unless the patient has undergone bilateral surgical pleurectomy and has normal lung function and chest CT scan postoperatively.

Overall, the BTS guidelines provide a comprehensive approach to the management of pneumothorax, taking into account the type of pneumothorax, patient characteristics, and potential complications.

A sudden decrease in haemoglobin is linked to aplastic crises in sickle cell disease. This condition is characterized by symptoms of anaemia and is often triggered by exposure to parvovirus B-19. The low reticulocyte count indicates acute bone marrow failure.

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

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

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

Understanding Primary Hyperaldosteronism

Primary hyperaldosteronism is a medical condition that was previously believed to be caused by an adrenal adenoma, also known as Conn’s syndrome. However, recent studies have shown that bilateral idiopathic adrenal hyperplasia is the cause in up to 70% of cases. It is important to differentiate between the two as this determines the appropriate treatment. Adrenal carcinoma is an extremely rare cause of primary hyperaldosteronism.

The common features of primary hyperaldosteronism include hypertension, hypokalaemia, and alkalosis. Hypokalaemia can cause muscle weakness, but this is seen in only 10-40% of patients. To diagnose primary hyperaldosteronism, the 2016 Endocrine Society recommends a plasma aldosterone/renin ratio as the first-line investigation. This should show high aldosterone levels alongside low renin levels due to negative feedback from sodium retention caused by aldosterone.

If the plasma aldosterone/renin ratio is high, a high-resolution CT abdomen and adrenal vein sampling are used to differentiate between unilateral and bilateral sources of aldosterone excess. If the CT is normal, adrenal venous sampling (AVS) can be used to distinguish between unilateral adenoma and bilateral hyperplasia. The management of primary hyperaldosteronism depends on the underlying cause. Adrenal adenoma is treated with surgery, while bilateral adrenocortical hyperplasia is treated with an aldosterone antagonist such as spironolactone.

In summary, primary hyperaldosteronism is a medical condition that can be caused by adrenal adenoma, bilateral idiopathic adrenal hyperplasia, or adrenal carcinoma. It is characterized by hypertension, hypokalaemia, and alkalosis. Diagnosis involves a plasma aldosterone/renin ratio, high-resolution CT abdomen, and adrenal vein sampling. Treatment depends on the underlying cause and may involve surgery or medication.

Inhibitory Postsynaptic Potentials (IPSPs)

Inhibitory postsynaptic potentials (IPSPs) are electrical charges generated in response to synaptic input that prevent the generation of additional action potentials in the postsynaptic neuron. This potential is generated after the postsynaptic action potential has fired, causing the membrane potential to become more negative, similar to the refractory period in the action potential sequence of events. IPSPs can be produced by the opening of chemical-gated potassium channels or GABA receptor chloride channels. The end result is a push of the membrane potential to a more negative charge, decreasing the likelihood of additional stimuli depolarizing it.

IPSPs are the opposite of excitatory postsynaptic potentials (EPSPs), which promote the generation of additional postsynaptic action potentials. It is important to note that only hyperpolarization of the postsynaptic membrane following neurotransmitter binding is correct. The other options are physiologically nonsensical.

Based on the information provided in the presentation and the patient’s medical history, it can be concluded that the patient is experiencing diabetic ketoacidosis (DKA), which results in metabolic acidosis and an elevated anion gap.

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 academic 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.

The most common cause of infective endocarditis is Staphylococcus aureus, especially in acute presentations and among intravenous drug users. However, if the patient has undergone valve replacement surgery more than 2 months ago, the spectrum of organisms causing endocarditis returns to normal, making Staphylococcus epidermidis less likely. While Streptococcus bovis can also cause endocarditis, it is not as common as Staphylococcus aureus and is associated with colon cancer. Staphylococcus epidermidis is the most common cause of endocarditis within 2 months post-valvular surgery. On the other hand, Streptococcus mitis, a viridans streptococcus found in the mouth, is associated with endocarditis following dental procedures or in patients with poor dental hygiene.

Aetiology of Infective Endocarditis

Infective endocarditis is a condition that affects patients with previously normal valves, rheumatic valve disease, prosthetic valves, congenital heart defects, intravenous drug users, and those who have recently undergone piercings. The strongest risk factor for developing infective endocarditis is a previous episode of the condition. The mitral valve is the most commonly affected valve.

The most common cause of infective endocarditis is Staphylococcus aureus, particularly in acute presentations and intravenous drug users. Historically, Streptococcus viridans was the most common cause, but this is no longer the case except in developing countries. Streptococcus mitis and Streptococcus sanguinis are the two most notable viridans streptococci, commonly found in the mouth and dental plaque. Coagulase-negative Staphylococci such as Staphylococcus epidermidis are the most common cause of endocarditis in patients following prosthetic valve surgery.

Streptococcus bovis is associated with colorectal cancer, with the subtype Streptococcus gallolyticus being most linked to the condition. Non-infective causes of endocarditis include systemic lupus erythematosus and malignancy. Culture negative causes may be due to prior antibiotic therapy or infections caused by Coxiella burnetii, Bartonella, Brucella, or HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella).

A reduction in flow-rate across the aortic valve and a murmur that is less audible are consequences of left ventricular systolic dysfunction.

Aortic Stenosis: Symptoms, Causes, and Management

Aortic stenosis is a condition characterized by the narrowing of the aortic valve, which can lead to various symptoms. These symptoms include chest pain, dyspnea, syncope, and a characteristic ejection systolic murmur that radiates to the carotids. Severe aortic stenosis can also cause a narrow pulse pressure, slow rising pulse, delayed ESM, soft/absent S2, S4, thrill, and left ventricular hypertrophy or failure. The most common causes of aortic stenosis are degenerative calcification in older patients and bicuspid aortic valve in younger patients.

If a patient is asymptomatic, observation is usually recommended. However, if the patient is symptomatic or has a valvular gradient greater than 40 mmHg with features such as left ventricular systolic dysfunction, valve replacement is necessary. Surgical AVR is the preferred treatment for young, low/medium operative risk patients, while TAVR is used for those with a high operative risk. Balloon valvuloplasty may be used in children without aortic valve calcification and in adults with critical aortic stenosis who are not fit for valve replacement.

In summary, aortic stenosis is a condition that can cause various symptoms and requires prompt management to prevent complications. The causes of aortic stenosis vary, and treatment options depend on the patient’s age, operative risk, and overall health.

The typical duration of treatment for unprovoked pulmonary embolisms is 6 months, with first-line treatment now being direct oral anticoagulants. Patients are usually reviewed after 3 months, and if no cause was found, treatment is continued for a further 3 months. 3 months would be appropriate for provoked embolisms, but as there was no clear cause in this case, 6 months is more appropriate. 4 months is not a standard duration of treatment, and 12 months is not usual either, although the doctor may decide to extend treatment after review. In some cases, lifelong anticoagulation may be recommended if an underlying prothrombotic condition is found, but for this patient, 6 months is appropriate.

Management of Pulmonary Embolism: NICE Guidelines

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

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

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

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

The likely diagnosis for this patient is hypercalcaemia, as indicated by their symptoms of polyuria, polydipsia, constipation, abdominal pain, depression, weakness, and fatigue. The main ECG abnormality associated with hypercalcaemia is a shortened QT interval. It is important to note that the presence of a J-wave is typically seen in hypothermia, not hypercalcaemia. Additionally, a prolonged QT interval is a feature of hypocalcaemia, not hypercalcaemia. Finally, tall tented T waves are characteristic of hyperkalaemia, not hypercalcaemia.

Hypercalcaemia: Symptoms and Signs

Hypercalcaemia is a medical condition characterized by high levels of calcium in the blood. The symptoms and signs of hypercalcaemia can be remembered by the phrase ‘bones, stones, groans and psychic moans’. This means that patients with hypercalcaemia may experience bone pain, kidney stones, constipation, and changes in mood or behavior. In addition, corneal calcification and a shortened QT interval on an electrocardiogram (ECG) may also be present. Hypertension, or high blood pressure, is another common feature of hypercalcaemia. It is important to seek medical attention if any of these symptoms are present, as hypercalcaemia can lead to serious complications if left untreated.

Diabetic ketoacidosis (DKA) is a serious complication of type 1 diabetes mellitus, accounting for around 6% of cases. It can also occur in rare cases of extreme stress in patients with type 2 diabetes mellitus. However, mortality rates have decreased from 8% to under 1% in the past 20 years. DKA is caused by uncontrolled lipolysis, resulting in an excess of free fatty acids that are ultimately converted to ketone bodies. The most common precipitating factors of DKA are infection, missed insulin doses, and myocardial infarction. Symptoms include abdominal pain, polyuria, polydipsia, dehydration, Kussmaul respiration, and acetone-smelling breath. Diagnostic criteria include glucose levels above 13.8 mmol/l, pH below 7.30, serum bicarbonate below 18 mmol/l, anion gap above 10, and ketonaemia.

Management of DKA involves fluid replacement, insulin, and correction of electrolyte disturbance. Most patients with DKA are depleted around 5-8 litres, and isotonic saline is used initially, even if the patient is severely acidotic. Insulin is administered through an intravenous infusion, and correction of electrolyte disturbance is necessary. Long-acting insulin should be continued, while short-acting insulin should be stopped. DKA resolution is defined as pH above 7.3, blood ketones below 0.6 mmol/L, and bicarbonate above 15.0mmol/L. Complications may occur from DKA itself or the treatment, such as gastric stasis, thromboembolism, arrhythmias, acute respiratory distress syndrome, acute kidney injury, and cerebral oedema. Children and young adults are particularly vulnerable to cerebral oedema following fluid resuscitation in DKA and often need 1:1 nursing to monitor neuro-observations.

Sjögren’s Syndrome and its Ocular Manifestations

Sjögren’s syndrome is an autoimmune disease that primarily affects the exocrine glands, leading to decreased production of tears and saliva. This results in dry eyes and dry mouth, which can cause corneal abrasions and even ulceration if left untreated. It is commonly associated with connective tissue diseases, particularly rheumatoid arthritis.

When it comes to ocular manifestations, it is important to differentiate Sjögren’s syndrome from other conditions such as scleritis, episcleritis, uveitis, and ulcerative keratitis. The phenylephrine test can help distinguish between episcleritis and scleritis, while uveitis typically presents with ocular pain, photophobia, and blurred vision. Ulcerative keratitis, on the other hand, has an infectious presentation and requires different treatment approaches depending on the depth of the ulcer.

Overall, the pathophysiology and ocular manifestations of Sjögren’s syndrome is crucial for proper diagnosis and management of this autoimmune disease.

Lambert-Eaton syndrome is a possible diagnosis for this patient’s symptoms. It is a rare disorder that can affect both the upper and lower motor neurons, causing proximal muscle weakness. It can occur as a paraneoplastic syndrome in a small percentage of cases, but it can also be an idiopathic autoimmune disorder in younger patients. Unlike Guillain-Barré syndrome, the weakness in LES does not improve with exercise, and the EMG shows an increment in muscle action potentials after exercise. Inclusion body myositis is unlikely as it typically affects the finger flexors rather than the hip flexors and the weakness is distal rather than proximal. Myasthenia gravis is also a differential diagnosis, but the weakness in this disorder worsens with exercise, whereas in LES, it does not.

Understanding Lambert-Eaton Syndrome

Lambert-Eaton syndrome is a rare neuromuscular disorder that is often associated with small cell lung cancer, breast cancer, and ovarian cancer. However, it can also occur independently as an autoimmune disorder. This condition is caused by an antibody that attacks the presynaptic voltage-gated calcium channel in the peripheral nervous system.

The symptoms of Lambert-Eaton syndrome include limb-girdle weakness, hyporeflexia, and autonomic symptoms such as dry mouth, impotence, and difficulty micturating. Unlike myasthenia gravis, ophthalmoplegia and ptosis are not commonly observed in this condition. Although repeated muscle contractions can lead to increased muscle strength, this is only seen in 50% of patients and muscle strength will eventually decrease following prolonged muscle use.

To diagnose Lambert-Eaton syndrome, an incremental response to repetitive electrical stimulation is observed during an electromyography (EMG) test. Treatment options include addressing the underlying cancer, immunosuppression with prednisolone and/or azathioprine, and the use of 3,4-diaminopyridine, which blocks potassium channel efflux in the nerve terminal to increase the action potential duration. Intravenous immunoglobulin therapy and plasma exchange may also be beneficial.

In summary, Lambert-Eaton syndrome is a rare neuromuscular disorder that can be associated with cancer or occur independently as an autoimmune disorder. It is characterized by limb-girdle weakness, hyporeflexia, and autonomic symptoms. Treatment options include addressing the underlying cancer, immunosuppression, and the use of 3,4-diaminopyridine, intravenous immunoglobulin therapy, and plasma exchange.

Widespread convulsions without loss of consciousness may indicate a psychogenic non-epileptic seizure (pseudoseizure), especially in a patient with psychiatric comorbidities. A focal aware seizure would not involve whole-body convulsions, while an alcohol withdrawal seizure would involve loss of consciousness. A panic attack may involve involuntary movement, but widespread convulsions would be unusual.

Understanding Psychogenic Non-Epileptic Seizures

Psychogenic non-epileptic seizures, also known as pseudoseizures, are a type of seizure that is not caused by abnormal electrical activity in the brain. Instead, they are believed to be caused by psychological factors such as stress, trauma, or anxiety. These seizures can be difficult to diagnose as they often mimic true epileptic seizures, but there are certain factors that can help differentiate between the two.

Factors that may indicate pseudoseizures include pelvic thrusting, a family history of epilepsy, a higher incidence in females, crying after the seizure, and the seizures not occurring when the individual is alone. On the other hand, factors that may indicate true epileptic seizures include tongue biting and a raised serum prolactin level.

Video telemetry is a useful tool for differentiating between the two types of seizures. It involves monitoring the individual’s brain activity and behavior during a seizure, which can help determine whether it is caused by abnormal electrical activity in the brain or psychological factors.

It is important to accurately diagnose and treat psychogenic non-epileptic seizures as they can have a significant impact on an individual’s quality of life. Treatment may involve therapy to address underlying psychological factors, as well as medication to manage any associated symptoms such as anxiety or depression.

An adrenaline infusion can be used as an alternative treatment for symptomatic bradycardia if transcutaneous pacing is not available. In this case, the patient requires rapid intervention to address their haemodynamic instability. Atropine infusion is not appropriate due to the patient’s allergy and potential to worsen their condition. Amiodarone is not useful in this situation, as it is typically used for other arrhythmias. Digoxin is not helpful in bradycardia and can actually reduce AV conduction speed. Glucagon is reserved for cases of cardiovascular failure caused by beta-blocker overdose, which is not the case for this patient.

Management of Bradycardia in Peri-Arrest Rhythms

The 2021 Resuscitation Council (UK) guidelines highlight that the management of bradycardia in peri-arrest rhythms depends on two factors. Firstly, identifying adverse signs that indicate haemodynamic compromise, such as shock, syncope, myocardial ischaemia, or heart failure. Secondly, identifying the potential risk of asystole, which can occur in patients with complete heart block with broad complex QRS, recent asystole, Mobitz type II AV block, or ventricular pause > 3 seconds.

If adverse signs are present, Atropine (500 mcg IV) is the first line treatment. If there is an unsatisfactory response, interventions such as atropine (up to a maximum of 3mg), transcutaneous pacing, or isoprenaline/adrenaline infusion titrated to response may be used. Specialist help should be sought for consideration of transvenous pacing if there is no response to the above measures.

Even if there is a satisfactory response to atropine, specialist help is indicated to consider the need for transvenous pacing in patients with risk factors for asystole. By following these guidelines, healthcare professionals can effectively manage bradycardia in peri-arrest rhythms and improve patient outcomes.