Acute kidney injury (AKI) is a condition where there is a sudden decrease in kidney function, which can be defined by a decrease in glomerular filtration rate (GFR) or a decrease in urine output. AKI can be caused by various factors such as prerenal, renal, or postrenal causes. Medications can also cause AKI, and caution should be taken when prescribing ACE inhibitors to patients with declining renal function. In the event of an AKI, certain medications such as ACE inhibitors, A2RBs, NSAIDs, diuretics, aminoglycosides, metformin, and lithium should be temporarily discontinued. Atorvastatin and bisoprolol are safe to prescribe in patients with kidney disease, while finasteride and tamsulosin can be prescribed for benign prostatic hyperplasia but should be used with caution in patients with poor renal function.

Understanding Acute Kidney Injury: A Basic Overview

Acute kidney injury (AKI) is a condition where the kidneys experience a reduction in function due to an insult. In the past, the kidneys were often neglected in acute medicine, resulting in slow recognition and limited action. However, around 15% of patients admitted to the hospital develop AKI. While most patients recover their renal function, some may have long-term impaired kidney function due to AKI, which can result in acute complications, including death. Identifying patients at increased risk of AKI is crucial in reducing its incidence. Risk factors for AKI include chronic kidney disease, other organ failure/chronic disease, a history of AKI, and the use of drugs with nephrotoxic potential.

AKI has three main causes: prerenal, intrinsic, and postrenal. Prerenal causes are due to a lack of blood flow to the kidneys, while intrinsic causes relate to intrinsic damage to the kidneys themselves. Postrenal causes occur when there is an obstruction to the urine coming from the kidneys. Symptoms of AKI include reduced urine output, fluid overload, arrhythmias, and features of uraemia. Diagnosis of AKI is made through blood tests, urinalysis, and imaging.

The management of AKI is largely supportive, with careful fluid balance and medication review being crucial. Loop diuretics and low-dose dopamine are not recommended, but hyperkalaemia needs prompt treatment to avoid life-threatening arrhythmias. Renal replacement therapy may be necessary in severe cases. Prompt review by a urologist is required for patients with suspected AKI secondary to urinary obstruction, while specialist input from a nephrologist is necessary for cases where the cause is unknown or the AKI is severe.

The risk of oesophageal adenocarcinoma is higher in individuals with Barrett’s oesophagus, whereas those with achalasia are at a greater risk of developing squamous cell carcinoma of the oesophagus.

Oesophageal Cancer: Types, Risk Factors, Features, Diagnosis, and Treatment

Oesophageal cancer used to be mostly squamous cell carcinoma, but adenocarcinoma is now becoming more common, especially in patients with a history of gastro-oesophageal reflux disease (GORD) or Barrett’s. Adenocarcinoma is usually located near the gastroesophageal junction, while squamous cell tumours are found in the upper two-thirds of the oesophagus.

Risk factors for adenocarcinoma include GORD, Barrett’s oesophagus, smoking, achalasia, and obesity. Squamous cell cancer is more common in the developing world and is associated with smoking, alcohol, achalasia, Plummer-Vinson syndrome, and diets rich in nitrosamines.

The most common presenting symptom for both types of oesophageal cancer is dysphagia, followed by anorexia and weight loss. Other possible features include odynophagia, hoarseness, melaena, vomiting, and cough.

Diagnosis is done through upper GI endoscopy with biopsy, endoscopic ultrasound for locoregional staging, CT scanning for initial staging, and FDG-PET CT for detecting occult metastases. Laparoscopy may also be performed to detect occult peritoneal disease.

Operable disease is best managed by surgical resection, with the most common procedure being an Ivor-Lewis type oesophagectomy. However, the biggest surgical challenge is anastomotic leak, which can result in mediastinitis. Adjuvant chemotherapy may also be used in many patients.

Overall, oesophageal cancer is a serious condition that requires prompt diagnosis and treatment. Understanding the types, risk factors, features, diagnosis, and treatment options can help patients and healthcare providers make informed decisions about managing this disease.

Management of Acute Asthma

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

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

If a patient with diabetic ketoacidosis still has significant ketonaemia and acidosis after 24 hours, it is recommended to seek a review from a senior endocrinologist. This is important to consider other potential diagnoses and advise on further treatment. Treatment should aim to reduce blood ketones by approximately 1 mmol/hr and glucose by around 3mmol/hr. By 24 hours, the patient should be eating and drinking normally and can be switched to subcutaneous insulin.

Admission to ICU is not necessary at this point as the patient is relatively stable. The priority is to continue treatment and determine why the current treatment is not working, which can be best achieved with a senior review.

Continuing the current fluid replacement would be inappropriate as patients with DKA should see resolution of their condition after 24 hours of normal treatment. If the patient remains in DKA after this point, a senior review is needed.

Increasing insulin rate, as well as increasing the rate of IV fluids, should not be done without consulting a senior endocrinologist as it may lead to hypoglycaemia or dilutional hyponatraemia, respectively, which could worsen the patient’s condition.

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.

Torsades de pointes can be caused by hypothermia. Other causes include hypocalcaemia, hypokalemia, and hypomagnesaemia, but not their hyper counterparts. There is no known link between hypoglycemia or hyperthyroidism and Torsades de Pointes.

Torsades de Pointes: A Life-Threatening Condition

Torsades de pointes is a type of ventricular tachycardia that is associated with a prolonged QT interval. This condition can lead to ventricular fibrillation, which can cause sudden death. There are several causes of a prolonged QT interval, including congenital conditions such as Jervell-Lange-Nielsen syndrome and Romano-Ward syndrome, as well as certain medications like antiarrhythmics, tricyclic antidepressants, and antipsychotics. Other causes include electrolyte imbalances, myocarditis, hypothermia, and subarachnoid hemorrhage.

The management of torsades de pointes involves the administration of intravenous magnesium sulfate. This can help to stabilize the heart rhythm and prevent further complications.

In cases of resistant diabetic neuropathy, pain management clinics may be considered for the management of pain. If a patient has already tried common medications for neuropathic pain and has almost reached the limit of care, referral to a pain management clinic is the most appropriate step. NICE recommends referral for patients with severe or worsening pain, or those whose pain impairs their daily life. Cannabis sativa extract and morphine are not typically used for neuropathic pain unless recommended by a specialist. Tramadol may be used for breakthrough pain in the acute setting, but is not suitable for long-term management of neuropathic pain. Advising a patient to improve their diabetic control will not necessarily improve their current pain, but may limit further neuropathy from occurring.

Diabetes can cause peripheral neuropathy, which typically results in sensory loss rather than motor loss. This often affects the lower legs first due to the length of the sensory neurons supplying this area, resulting in a glove and stocking distribution. Painful diabetic neuropathy is a common issue that can be managed with drugs such as amitriptyline, duloxetine, gabapentin, or pregabalin. If these drugs do not work, tramadol may be used as a rescue therapy, and topical capsaicin may be used for localized neuropathic pain. Pain management clinics may also be helpful for patients with resistant problems.

Gastrointestinal autonomic neuropathy can cause gastroparesis, which can lead to erratic blood glucose control, bloating, and vomiting. This can be managed with prokinetic agents such as metoclopramide, domperidone, or erythromycin. Chronic diarrhea, which often occurs at night, is another potential complication of diabetic neuropathy. Gastroesophageal reflux disease can also occur due to decreased lower esophageal sphincter pressure.

When hypothermia leads to cardiac arrest, defibrillation is not as effective and should be limited to three shocks before the patient is warmed up to 30 degrees Celsius. Pacing is also ineffective until the patient reaches normal body temperature. Medications should be held off until the patient reaches 30 degrees Celsius, and then administered at double the usual intervals until the patient achieves normal body temperature or experiences the return of spontaneous circulation (ROSC).

Hypothermia is a condition where the core body temperature drops below normal levels, often caused by exposure to cold environments. It is most common in the winter and the elderly are particularly susceptible. Signs include shivering, cold and pale skin, slurred speech, and confusion. Treatment involves removing the patient from the cold environment, warming the body with blankets, securing the airway, and monitoring breathing. Rapid re-warming should be avoided as it can lead to peripheral vasodilation and shock. Certain actions, such as putting the person in a hot bath or giving them alcohol, should be avoided.

Neutropenic sepsis is a serious condition that requires immediate treatment with antibiotics. Piperacillin with tazobactam (Tazocin) is the preferred antibiotic for this condition, even before neutropenia is confirmed on blood testing. This combination works by breaking down the cell walls of bacteria and preventing bacterial resistance to piperacillin. However, if a patient is unable to tolerate Tazocin, alternative antibiotics should be considered based on local guidelines or microbiology advice.

Amoxicillin with clavulanic acid and gentamicin are other antibiotics that can be used for severe infections, but they are not the best choice for neutropenic sepsis. Aztreonam and vancomycin can be used in combination when Tazocin is not an option, but a third antibiotic may be necessary for additional coverage. It is important to note that gentamicin should be used with caution due to the risk of kidney damage and ototoxicity.

Neutropenic Sepsis: A Common Complication of Cancer Therapy

Neutropenic sepsis is a frequent complication of cancer therapy, particularly chemotherapy. It typically occurs within 7-14 days after chemotherapy and is characterized by a neutrophil count of less than 0.5 * 109 in patients undergoing anticancer treatment who exhibit a temperature higher than 38ºC or other signs or symptoms consistent with clinically significant sepsis.

To prevent neutropenic sepsis, patients who are likely to have a neutrophil count of less than 0.5 * 109 as a result of their treatment should be offered a fluoroquinolone. In the event of neutropenic sepsis, antibiotics must be initiated immediately, without waiting for the white blood cell count.

According to NICE guidelines, empirical antibiotic therapy should begin with piperacillin with tazobactam (Tazocin) immediately. While some units may add vancomycin if the patient has central venous access, NICE does not support this approach. After initial treatment, patients are typically assessed by a specialist and risk-stratified to determine if they may be able to receive outpatient treatment.

If patients remain febrile and unwell after 48 hours, an alternative antibiotic such as meropenem may be prescribed, with or without vancomycin. If patients do not respond after 4-6 days, the Christie guidelines suggest ordering investigations for fungal infections (e.g. HRCT) rather than blindly initiating antifungal therapy. In selected patients, G-CSF may be beneficial.

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.

If serum transaminase levels remain consistently 3 times higher than the upper limit of the reference range, treatment with statins must be stopped.

Statins are drugs that inhibit the action of an enzyme called HMG-CoA reductase, which is responsible for producing cholesterol in the liver. However, they can cause some adverse effects such as myopathy, which includes muscle pain, weakness, and damage, and liver impairment. Myopathy is more common in lipophilic statins than in hydrophilic ones. Statins may also increase the risk of intracerebral hemorrhage in patients who have had a stroke before. Therefore, they should be avoided in these patients. Statins should not be taken during pregnancy and should be stopped if the patient is taking macrolides.

Statins are recommended for people with established cardiovascular disease, those with a 10-year cardiovascular risk of 10% or more, and patients with type 2 diabetes mellitus. Patients with type 1 diabetes mellitus who were diagnosed more than 10 years ago, are over 40 years old, or have established nephropathy should also take statins. It is recommended to take statins at night as this is when cholesterol synthesis takes place. Atorvastatin 20 mg is recommended for primary prevention, and the dose should be increased if non-HDL has not reduced for 40% or more. Atorvastatin 80mg is recommended for secondary prevention. The graphic shows the different types of statins available.

Hyperventilation leads to a respiratory alkalosis (non-compensated) due to the reduction in carbon dioxide levels.

Disorders of Acid-Base Balance: An Overview

The acid-base normogram is a useful tool for categorizing the various disorders of acid-base balance. Metabolic acidosis is the most common surgical acid-base disorder, characterized by a reduction in plasma bicarbonate levels. This can be caused by a gain of strong acid (such as in diabetic ketoacidosis) or a loss of base (such as from bowel in diarrhea). Metabolic alkalosis, on the other hand, is usually caused by a rise in plasma bicarbonate levels, which can be due to problems of the kidney or gastrointestinal tract. Respiratory acidosis occurs when there is a rise in carbon dioxide levels, usually as a result of alveolar hypoventilation, while respiratory alkalosis results from hyperventilation, leading to excess loss of carbon dioxide.

Each of these disorders has its own set of causes and mechanisms. For example, metabolic alkalosis can be caused by vomiting/aspiration, diuretics, or primary hyperaldosteronism, among other factors. The mechanism of metabolic alkalosis involves the activation of the renin-angiotensin II-aldosterone (RAA) system, which causes reabsorption of Na+ in exchange for H+ in the distal convoluted tubule. Respiratory acidosis, on the other hand, can be caused by COPD, decompensation in other respiratory conditions, or sedative drugs like benzodiazepines and opiate overdose.

It is important to understand the different types of acid-base disorders and their causes in order to properly diagnose and treat them. By using the acid-base normogram and understanding the underlying mechanisms, healthcare professionals can provide effective interventions to restore balance to the body’s acid-base system.

Fractures in the middle of the humerus bone often result in damage to the radial nerve. Therefore, it is important to test the function of the radial nerve. Among the options given, only extending the wrist can effectively test the radial nerve as it provides innervation to the extensor muscles. If the radial nerve is affected, it can cause wrist drop.
While extending the elbow can also test the radial nerve, it may not provide as much information as wrist extension because the injury may be located proximal to the innervation of the triceps. This means that a more distal injury could be missed. Nonetheless, it is still likely to be performed as part of the testing process.
Reference:
Shao YC, Harwood P, Grotz MR, et al. (2005). Radial nerve palsy associated with fractures of the shaft of the humerus: a systematic review. J Bone Joint Surg Br; 87(12):1647-52.

Anatomy and Function of the Radial Nerve

The radial nerve is a continuation of the posterior cord of the brachial plexus, with root values ranging from C5 to T1. It has both motor and sensory functions, innervating muscles in the arm and forearm, as well as providing sensation to the dorsal aspect of the hand.

The nerve follows a path from the axilla, where it lies posterior to the axillary artery on subscapularis, latissimus dorsi, and teres major, to the arm, where it enters between the brachial artery and the long head of triceps. It spirals around the posterior surface of the humerus in the groove for the radial nerve before piercing the intermuscular septum and descending in front of the lateral epicondyle. At the lateral epicondyle, it divides into a superficial and deep terminal branch, with the deep branch crossing the supinator to become the posterior interosseous nerve.

The radial nerve innervates several muscles, including triceps, anconeus, brachioradialis, and extensor carpi radialis. Damage to the nerve can result in wrist drop and sensory loss to a small area between the dorsal aspect of the 1st and 2nd metacarpals. In the forearm, the nerve innervates the supinator, extensor carpi ulnaris, extensor digitorum, extensor indicis, extensor digiti minimi, extensor pollicis longus and brevis, and abductor pollicis longus. Paralysis of these muscles can result in weakening of supination of prone hand and elbow flexion in mid prone position.

Understanding the anatomy and function of the radial nerve is important in diagnosing and treating injuries or conditions that affect its function.

Haemodialysis, sickle-cell anaemia, GP6D deficiency, and hereditary spherocytosis are conditions that can cause premature red blood cell death, leading to invalid results when measuring HbA1c levels. HbA1c is a form of haemoglobin that indicates the three-month average blood sugar level. Haemodialysis, in particular, can result in lower-than-expected HbA1c levels due to its reduction of red blood cell lifespan. Amoxicillin and citalopram are not known to affect HbA1c levels, while drugs like trimethoprim-sulfamethoxazole can increase erythrocyte destruction and cause inappropriately low HbA1c levels. Iron-deficiency anaemia, on the other hand, can cause higher-than-expected HbA1c levels, making it crucial to treat the condition to accurately track diabetic control.

Understanding Glycosylated Haemoglobin (HbA1c) in Diabetes Mellitus

Glycosylated haemoglobin (HbA1c) is a commonly used measure of long-term blood sugar control in diabetes mellitus. It is produced when glucose attaches to haemoglobin in the blood at a rate proportional to the glucose concentration. The level of HbA1c is influenced by the lifespan of red blood cells and the average blood glucose concentration. However, certain conditions such as sickle-cell anaemia, GP6D deficiency, and haemodialysis can interfere with accurate interpretation of HbA1c levels.

HbA1c is believed to reflect the blood glucose levels over the past 2-4 weeks, although it is generally thought to represent the previous 3 months. It is recommended that HbA1c be checked every 3-6 months until stable, then every 6 months. The Diabetes Control and Complications Trial (DCCT) has studied the complex relationship between HbA1c and average blood glucose. The International Federation of Clinical Chemistry (IFCC) has developed a new standardised method for reporting HbA1c in mmol per mol of haemoglobin without glucose attached.

The table above shows the relationship between HbA1c, average plasma glucose, and IFCC-HbA1c. By using this table, we can calculate the average plasma glucose level by multiplying HbA1c by 2 and subtracting 4.5. Understanding HbA1c is crucial in managing diabetes mellitus and achieving optimal blood sugar control.

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.

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.

For palliative care patients with severe renal impairment, fentanyl or buprenorphine are the preferred opioids for pain relief. This is because they are not excreted through the kidneys, reducing the risk of toxicity compared to morphine. Fentanyl is the top choice due to its liver metabolism, making it less likely to cause harm in patients with a glomerular filtration rate (GFR) of less than 10 mL/min/1.73². Oxycodone can be used in mild to moderate renal impairment (GFR 10-50 mL/min/1.73²), but it should be avoided in severe cases as it is partially excreted through the kidneys. Ibuprofen is not recommended as it is a weaker pain reliever than opioids and is contraindicated in patients with poor renal function.

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

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

If the level of LDH in an effusion is greater than 2/3rds of the upper limit of LDH in the serum, it indicates an exudate according to Light’s criteria.

Investigating and Managing Pleural Effusion: BTS Guidelines

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

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

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

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

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

The first-line treatment for syphilis is intramuscular benzathine penicillin, which is the correct management for the most likely diagnosis based on the patient’s symptoms of rash, lymphadenopathy, buccal ulcers, and condylomata, indicating secondary syphilis. The presence of a palmar rash is highly indicative of syphilis, although HIV should also be tested for as it can coexist with syphilis and present with similar symptoms. Cryotherapy is a treatment option for genital warts, but the flat white appearance of the wart-like lesions described here suggests they are more likely to be condylomata lata. The suggestion of no specific treatment except hydration and rest is incorrect, as this would only be appropriate for self-limiting viral illnesses such as Epstein-Barr virus, which is a potential differential diagnosis but less likely given the characteristic rash and history of the patient.

Management of Syphilis

Syphilis can be effectively managed with intramuscular benzathine penicillin as the first-line treatment. In cases where penicillin cannot be used, doxycycline may be used as an alternative. After treatment, nontreponemal titres such as rapid plasma reagin (RPR) or Venereal Disease Research Laboratory (VDRL) should be monitored to assess the response. A fourfold decline in titres is often considered an adequate response to treatment.

It is important to note that the Jarisch-Herxheimer reaction may occur following treatment. This reaction is characterized by fever, rash, and tachycardia after the first dose of antibiotic. Unlike anaphylaxis, there is no wheezing or hypotension. The reaction is thought to be due to the release of endotoxins following bacterial death and typically occurs within a few hours of treatment. However, no treatment is needed other than antipyretics if required.

In summary, the management of syphilis involves the use of intramuscular benzathine penicillin or doxycycline as an alternative. Nontreponemal titres should be monitored after treatment, and the Jarisch-Herxheimer reaction may occur but does not require treatment unless symptomatic.

Propranolol is the preferred medication for migraine prevention in women of childbearing age, as it is safer than topiramate which is teratogenic. Both medications are equally effective, but propranolol has a better side effects profile. Amitriptyline can also be used for migraine prophylaxis, but it is usually reserved for cases where propranolol and topiramate are ineffective. Paracetamol is only recommended for acute management of migraine, while sumatriptan is only recommended for acute management and should not be taken more than twice a week to avoid medication overuse headaches.

Managing Migraines: Guidelines and Treatment Options

Migraines can be debilitating and affect a significant portion of the population. To manage migraines, it is important to understand the different treatment options available. According to the National Institute for Health and Care Excellence (NICE) guidelines, acute treatment for migraines involves a combination of an oral triptan and an NSAID or paracetamol. For young people aged 12-17 years, a nasal triptan may be preferred. If these measures are not effective, non-oral preparations of metoclopramide or prochlorperazine may be considered, along with a non-oral NSAID or triptan.

Prophylaxis should be given if patients are experiencing two or more attacks per month. NICE recommends topiramate or propranolol, depending on the patient’s preference, comorbidities, and risk of adverse events. Propranolol is preferred in women of childbearing age as topiramate may be teratogenic and reduce the effectiveness of hormonal contraceptives. Acupuncture and riboflavin may also be effective in reducing migraine frequency and intensity for some people. For women with predictable menstrual migraines, frovatriptan or zolmitriptan may be recommended as a type of mini-prophylaxis.

Specialists may consider other treatment options, such as candesartan or monoclonal antibodies directed against the calcitonin gene-related peptide (CGRP) receptor, like erenumab. However, pizotifen is no longer recommended due to common adverse effects like weight gain and drowsiness. It is important to exercise caution with young patients as acute dystonic reactions may develop. By following these guidelines and considering various treatment options, migraines can be effectively managed.

The M rule for primary biliary cholangitis includes the presence of IgM and anti-Mitochondrial antibodies, specifically the M2 subtype, in middle-aged women.

Primary Biliary Cholangitis: A Chronic Liver Disorder

Primary biliary cholangitis, previously known as primary biliary cirrhosis, is a chronic liver disorder that is commonly observed in middle-aged women. The exact cause of this condition is not yet fully understood, but it is believed to be an autoimmune disease. The disease is characterized by the progressive damage of interlobular bile ducts due to chronic inflammation, leading to cholestasis and eventually cirrhosis. The most common symptom of primary biliary cholangitis is itching in middle-aged women.

This condition is often associated with other autoimmune diseases such as Sjogren’s syndrome, rheumatoid arthritis, systemic sclerosis, and thyroid disease. Early symptoms of primary biliary cholangitis may be asymptomatic or may include fatigue, pruritus, and cholestatic jaundice. Late symptoms may progress to liver failure. Diagnosis of primary biliary cholangitis involves immunology tests such as anti-mitochondrial antibodies (AMA) M2 subtype and smooth muscle antibodies, as well as imaging tests to exclude an extrahepatic biliary obstruction.

The first-line treatment for primary biliary cholangitis is ursodeoxycholic acid, which slows down the progression of the disease and improves symptoms. Cholestyramine is used to alleviate pruritus, and fat-soluble vitamin supplementation is recommended. In severe cases, liver transplantation may be necessary, especially if bilirubin levels exceed 100. However, recurrence in the graft can occur, but it is not usually a problem. Complications of primary biliary cholangitis include cirrhosis, portal hypertension, ascites, variceal hemorrhage, osteomalacia, osteoporosis, and an increased risk of hepatocellular carcinoma.

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.

The presence of pernicious anaemia, as indicated by the patient’s macrocytic anaemia and positive intrinsic factor antibodies, can increase the risk of developing gastric carcinoma. Pernicious anaemia is an autoimmune disease that impairs the production of intrinsic factor, leading to low levels of vitamin B12 and anaemia. While chronic lymphocytic leukaemia and non-Hodgkin’s lymphoma are not strongly linked to pernicious anaemia, they may be associated with genetic mutations acquired over time. Gastritis, which is not a serious complication, is more commonly associated with conditions such as Helicobacter pylori infection.

Understanding Pernicious Anaemia

Pernicious anaemia is a condition that results in vitamin B12 deficiency due to an autoimmune disorder affecting the gastric mucosa. The term pernicious means causing harm in a gradual or subtle way, and this is reflected in the often subtle symptoms and delayed diagnosis of the condition. While pernicious anaemia is the most common cause of vitamin B12 deficiency, other causes include atrophic gastritis, gastrectomy, and malnutrition.

The pathophysiology of pernicious anaemia involves antibodies to intrinsic factor and/or gastric parietal cells. These antibodies can bind to intrinsic factor, blocking the vitamin B12 binding site, or reduce acid production and cause atrophic gastritis. This leads to reduced intrinsic factor production and reduced vitamin B12 absorption, which can result in megaloblastic anaemia and neuropathy.

Risk factors for pernicious anaemia include being female, middle to old age, and having other autoimmune disorders such as thyroid disease, type 1 diabetes mellitus, Addison’s, rheumatoid arthritis, and vitiligo. It is also more common in individuals with blood group A.

Symptoms of pernicious anaemia include anaemia features such as lethargy, pallor, and dyspnoea, as well as neurological features such as peripheral neuropathy and subacute combined degeneration of the spinal cord. Neuropsychiatric features such as memory loss, poor concentration, confusion, depression, and irritability may also be present, along with mild jaundice and glossitis.

Diagnosis of pernicious anaemia involves a full blood count, vitamin B12 and folate levels, and testing for antibodies such as anti intrinsic factor antibodies and anti gastric parietal cell antibodies. Treatment involves vitamin B12 replacement, usually given intramuscularly, and folic acid supplementation may also be required. Complications of pernicious anaemia include an increased risk of gastric cancer.

The patient is experiencing hypokalaemic metabolic alkalosis, which is a common feature of Cushing’s syndrome. This condition is caused by an excess of corticosteroids, which can be exacerbated by corticosteroid therapy. The patient’s symptoms, such as central adiposity, stretch marks, bruising, hirsutism, and acne, are all indicative of Cushing’s syndrome.

Hypokalaemic metabolic alkalosis occurs when cortisol levels are high, allowing cortisol to bind to mineralocorticoid receptors. This leads to an increase in water and sodium retention, increased potassium excretion, and increased hydrogen ion excretion. The resulting decrease in hydrogen ions causes alkalosis, while the decrease in potassium causes hypokalemia.

Hyperchloremic metabolic acidosis, on the other hand, is caused by bicarbonate loss, usually due to diarrhea. The patient does not report any gastrointestinal symptoms, so this is unlikely to be the cause. Hyperkalaemic metabolic acidosis is associated with type 4 renal tubular acidosis and hypoaldosteronism, which is not consistent with the patient’s symptoms. Hyperkalaemic metabolic alkalosis is also unlikely, as a decrease in hydrogen ions would lead to a decrease in potassium ions. Finally, hypochloremic metabolic alkalosis is most commonly caused by vomiting, which the patient did not report.

Investigations for Cushing’s Syndrome

Cushing’s syndrome is a condition caused by excessive cortisol production in the body. There are various causes of Cushing’s syndrome, including iatrogenic, ACTH-dependent, and ACTH-independent causes. To diagnose Cushing’s syndrome, doctors typically perform tests to confirm the condition and determine its underlying cause.

General lab findings consistent with Cushing’s syndrome include hypokalaemic metabolic alkalosis and impaired glucose tolerance. Ectopic ACTH secretion, which is often associated with small cell lung cancer, is characterized by very low potassium levels.

The two most commonly used tests to confirm Cushing’s syndrome are the overnight dexamethasone suppression test and the 24-hour urinary free cortisol test. The overnight dexamethasone suppression test is the most sensitive test and is used first-line to test for Cushing’s syndrome. Patients with Cushing’s syndrome do not have their morning cortisol spike suppressed. The 24-hour urinary free cortisol test measures the amount of cortisol in the urine over a 24-hour period.

To localize the cause of Cushing’s syndrome, doctors may perform additional tests such as high-dose dexamethasone suppression test, CRH stimulation, and petrosal sinus sampling of ACTH. An insulin stress test may also be used to differentiate between true Cushing’s and pseudo-Cushing’s. Overall, a combination of these tests can help diagnose Cushing’s syndrome and determine its underlying cause.

Myasthenia gravis is an autoimmune disorder that results in insufficient functioning acetylcholine receptors. It is more common in women and is characterized by muscle fatigability, extraocular muscle weakness, proximal muscle weakness, ptosis, and dysphagia. Thymomas are present in 15% of cases, and autoimmune disorders are also associated with the disease. Diagnosis is made through single fibre electromyography and CT thorax to exclude thymoma. Management includes long-acting acetylcholinesterase inhibitors, immunosuppression, and thymectomy. Plasmapheresis and intravenous immunoglobulins are used to manage myasthenic crisis. Antibodies to acetylcholine receptors are seen in 85-90% of cases.

Trimethoprim can lead to tubular dysfunction, which can result in hyperkalemia and an increase in serum creatinine levels.

This statement is accurate, as trimethoprim can block the ENaC channel in the distal nephron, causing a type 4 hyperkalemic distal renal tubular acidosis. In this patient’s case, the use of trimethoprim, along with her regular medications, has caused acute kidney injury. It is important to avoid using trimethoprim in patients taking renin angiotensin antagonist drugs or potassium-sparing diuretics, or to monitor renal function closely.

However, the statement that hypercalcemia is a common occurrence in acute kidney injury is incorrect. Hypocalcemia is more commonly seen in this condition. Similarly, hypernatremia is not a common finding in acute kidney injury, as hyponatremia is more frequently observed. On the other hand, hyperphosphatemia is a common occurrence in acute kidney injury due to phosphate retention.

Understanding Trimethoprim: Mechanism of Action, Adverse Effects, and Use in Pregnancy

Trimethoprim is an antibiotic that is commonly used to treat urinary tract infections. Its mechanism of action involves interfering with DNA synthesis by inhibiting dihydrofolate reductase. This can potentially interact with methotrexate, which also inhibits dihydrofolate reductase. However, the use of trimethoprim can also lead to adverse effects such as myelosuppression and a transient rise in creatinine. The drug can competitively inhibit the tubular secretion of creatinine, resulting in a temporary increase that reverses upon stopping the drug. Additionally, trimethoprim can block the ENaC channel in the distal nephron, causing a hyperkalaemic distal RTA (type 4). It can also inhibit creatinine secretion, often leading to an increase in creatinine by around 40 points, but not necessarily causing AKI.

When it comes to the use of trimethoprim in pregnancy, caution is advised. The British National Formulary (BNF) warns of a teratogenic risk in the first trimester due to its folate antagonist properties. As such, manufacturers advise avoiding the use of trimethoprim during pregnancy. It is important to understand the potential risks and benefits of using this antibiotic and to consult with a healthcare provider before taking any medication.

Adults with polycystic kidney disease are at an increased risk of experiencing subarachnoid haemorrhage due to ruptured berry aneurysms. This is the most significant associated condition, as ADPKD is known to be linked with cerebral berry aneurysms that can rupture and cause subarachnoid haemorrhage. Liver cysts are the most common complication of ADPKD, while colonic diverticula and bowel obstruction are less frequent. Although ADPKD can cause splenic cysts and splenomegaly, this is also less common than the risk of subarachnoid haemorrhage due to cerebral berry aneurysms.

Autosomal dominant polycystic kidney disease (ADPKD) is a prevalent genetic condition that affects approximately 1 in 1,000 Caucasians. The disease is caused by mutations in two genes, PKD1 and PKD2, which produce polycystin-1 and polycystin-2, respectively. ADPKD type 1 accounts for 85% of cases, while ADPKD type 2 accounts for the remaining 15%. Individuals with ADPKD develop multiple fluid-filled cysts in their kidneys, which can lead to renal failure.

To diagnose ADPKD in individuals with a positive family history, an abdominal ultrasound is typically performed. The diagnostic criteria for ultrasound include the presence of two cysts, either unilateral or bilateral, in individuals under 30 years of age, two cysts in both kidneys for those aged 30-59 years, and four cysts in both kidneys for those over 60 years of age.

Management of ADPKD may involve the use of tolvaptan, a vasopressin receptor 2 antagonist, for select patients. Tolvaptan has been recommended by NICE as an option for treating ADPKD in adults with chronic kidney disease stage 2 or 3 at the start of treatment, evidence of rapidly progressing disease, and if the company provides it with the agreed discount in the patient access scheme. The goal of treatment is to slow the progression of cyst development and renal insufficiency. An enlarged kidney with extensive cysts is a common finding in individuals with ADPKD.

Parvovirus can be indicated by a sudden onset of anemia and a low reticulocyte count, while a high reticulocyte count may be caused by acute sequestration and hemolysis.

Sickle-cell anaemia is a genetic disorder that occurs when abnormal haemoglobin, known as HbS, is produced due to an autosomal recessive condition. This condition is more common in individuals of African descent, as the heterozygous condition provides some protection against malaria. About 10% of UK Afro-Caribbean are carriers of HbS, and they only experience symptoms if they are severely hypoxic. Homozygotes tend to develop symptoms between 4-6 months when the abnormal HbSS molecules replace fetal haemoglobin.

The pathophysiology of sickle-cell anaemia involves the substitution of the polar amino acid glutamate with the non-polar valine in each of the two beta chains (codon 6) of haemoglobin. This substitution decreases the water solubility of deoxy-Hb, causing HbS molecules to polymerise and sickle RBCs in the deoxygenated state. HbAS patients sickle at p02 2.5 – 4 kPa, while HbSS patients sickle at p02 5 – 6 kPa. Sickle cells are fragile and haemolyse, blocking small blood vessels and causing infarction.

The definitive diagnosis of sickle-cell anaemia is through haemoglobin electrophoresis.

Distinguishing between pseudoseizures and true seizures can be challenging as they share some similarities. However, one key difference is that pseudoseizures tend to have a gradual onset, while true seizures have a sudden onset. Pseudoseizures are often linked to psychiatric conditions and are not voluntary, but rather compulsive and unwanted movements. It is common for individuals experiencing pseudoseizures to have some control over the location of their symptoms. While dystonia may involve shaking, it typically results in rigidity rather than gradual onset and offset.

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.

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.