The ulnar nerve provides innervation to several muscles in the hand. These include the palmar interossei, dorsal interossei, medial two lumbricals, and the abductor digiti minimi. It is important to note that the lateral two lumbricals are not affected by an ulnar nerve lesion as they are innervated by the median nerve.

Acute epiglottitis is inflammation of the epiglottis, which can be life-threatening if not treated promptly. When the soft tissues surrounding the epiglottis are also affected, it is called acute supraglottitis. This condition is most commonly seen in children between the ages of 3 and 5, but it can occur at any age, with adults typically presenting in their 40s and 50s.

In the past, Haemophilus influenzae type B was the main cause of acute epiglottitis, but with the introduction of the Hib vaccination, it has become rare in children. Streptococcus spp. is now the most common causative organism. Other potential culprits include Staphylococcus aureus, Pseudomonas spp., Moraxella catarrhalis, Mycobacterium tuberculosis, and the herpes simplex virus. In immunocompromised patients, Candida spp. and Aspergillus spp. infections can occur.

The typical symptoms of acute epiglottitis include fever, sore throat, painful swallowing, difficulty swallowing secretions (especially in children who may drool), muffled voice, stridor, respiratory distress, rapid heartbeat, tenderness in the front of the neck over the hyoid bone, ear pain, and swollen lymph nodes in the neck. Some patients may also exhibit the tripod sign, where they lean forward on outstretched arms to relieve upper airway obstruction.

To diagnose acute epiglottitis, fibre-optic laryngoscopy is considered the gold standard investigation. However, this procedure should only be performed by an anaesthetist in a setting prepared for intubation or tracheostomy in case of airway obstruction. Other useful tests include a lateral neck X-ray to look for the thumbprint sign, throat swabs, blood cultures, and a CT scan of the neck if an abscess is suspected.

When dealing with a case of acute epiglottitis, it is crucial not to panic or distress the patient, especially in pediatric cases. Avoid attempting to examine the throat with a tongue depressor, as this can trigger spasm and worsen airway obstruction. Instead, keep the patient as calm as possible and immediately call a senior anaesthetist, a senior paediatrician, and an ENT surgeon. Nebulized adrenaline can be used as a temporary measure if there is critical airway obstruction.

Oral rehydration therapy (ORT) is a method used to prevent or treat dehydration by replacing fluids in the body. It is a less invasive approach compared to other methods and has been successful in reducing the mortality rate of diarrhea in developing nations.

ORT includes glucose, such as 90 mmol/L in Dioralyte, which helps improve the absorption of sodium and water in the intestines and prevents low blood sugar levels. It also contains essential mineral salts.

According to current guidelines from the National Institute for Health and Care Excellence (NICE), for mild dehydration, it is recommended to administer 50 mL/kg of ORT over a period of 4 hours.

Once a child has been rehydrated, they should continue their normal daily fluid intake and consume an additional 200 ml of ORT after each loose stool. For infants, ORT should be given at 1-1.5 times their regular feeding volume, while adults should consume 200-400 mL of ORT after each loose stool.

For more information, you can refer to the NICE guidelines on the diagnosis and management of diarrhea and vomiting caused by gastroenteritis in children under 5 years old.

This patient’s clinical presentation is consistent with a diagnosis of idiopathic pulmonary fibrosis. The typical symptoms of idiopathic pulmonary fibrosis include a dry cough, progressive breathlessness, arthralgia and muscle pain, finger clubbing (seen in 50% of cases), cyanosis, fine end-expiratory bibasal crepitations, and right heart failure and cor pulmonale in later stages.

Finger clubbing, which is prominent in this patient, can also be caused by bronchiectasis and tuberculosis. However, these conditions would not result in a raised FEV1/FVC ratio, which is a characteristic feature of a restrictive lung disorder.

In restrictive lung disease, the FEV1/FVC ratio is typically normal, around 70% predicted, while the FVC is reduced to less than 80% predicted. Both the FVC and FEV1 are generally reduced in this condition. The ratio can also be elevated if the FVC is reduced to a greater extent.

It is important to note that smoking is a risk factor for developing idiopathic pulmonary fibrosis, particularly in individuals with a history of smoking greater than 20 pack-years.

Diabetic amyotrophy, also referred to as proximal diabetic neuropathy, is the second most prevalent form of diabetic neuropathy. It typically manifests with pain in the buttocks, hips, or thighs and is often initially experienced on one side of the body. The pain may start off as mild and gradually progress or it can suddenly appear, as seen in this particular case. Subsequently, weakness and wasting of the proximal muscles in the lower limbs occur, potentially leading to the patient requiring assistance when transitioning from a seated to a standing position. Reflexes in the affected areas can also be impacted. Fortunately, diabetic amyotrophy can be reversed through effective management of blood sugar levels, physiotherapy, and adopting a healthy lifestyle.

This child has a past medical history consistent with acute purulent otitis media on the left side. The sudden improvement and discharge of pus from the ear strongly suggest a perforated tympanic membrane. It is not uncommon to be unable to see the tympanic membrane in these situations.

Initially, it is best to adopt a watchful waiting approach to tympanic membrane perforation. Spontaneous healing occurs in over 90% of patients, so only persistent cases should be referred for myringoplasty. There is no need for an urgent same-day referral in this case.

The use of topical corticosteroids and gentamicin is not recommended when there is a tympanic membrane perforation.

Lithium is a commonly prescribed medication for bipolar disorder, as it helps stabilize mood. The recommended therapeutic range for lithium levels is typically between 0.4 and 0.8 mmol/l, although this range may vary depending on the laboratory. For maintenance therapy and treatment in older individuals, the lower end of the range is usually targeted. Toxic effects of lithium are typically observed when levels exceed 1.5 mmol/l. It is important to monitor lithium levels one week after starting therapy and after any dosage adjustments.

One potential side effect of lithium is the development of nephrogenic diabetes insipidus, a condition that affects the kidneys’ ability to concentrate urine. However, lithium does not cause diabetes mellitus. Another known side effect is hypothyroidism, which is a decrease in thyroid hormone production, but it does not lead to hyperthyroidism, an overactive thyroid.

Signs of lithium toxicity include nausea, vomiting, diarrhea, tremors, ataxia (loss of coordination), confusion, increased muscle tone, clonus (repetitive, involuntary muscle contractions), nephrogenic diabetes insipidus, convulsions, coma, and renal failure. It is crucial to be aware of these symptoms and seek medical attention if they occur.

For mild cases of otitis externa, using ear drops or spray as the initial treatment is a reasonable option. The insertion of a medicated wick, known as a Pope wick, is typically reserved for patients with severely narrowed external auditory canals. Microsuction, on the other hand, is helpful for patients with excessive debris in their ear canal but is not necessary for this particular patient. In general, microsuction is usually only used for severe cases of otitis externa that require referral to an ear, nose, and throat specialist for further management.

Further Reading:

Otitis externa is inflammation of the skin and subdermis of the external ear canal. It can be acute, lasting less than 6 weeks, or chronic, lasting more than 3 months. Malignant otitis externa, also known as necrotising otitis externa, is a severe and potentially life-threatening infection that can spread to the bones and surrounding structures of the ear. It is most commonly caused by Pseudomonas aeruginosa.

Symptoms of malignant otitis externa include severe and persistent ear pain, headache, discharge from the ear, fever, malaise, vertigo, and profound hearing loss. It can also lead to facial nerve palsy and other cranial nerve palsies. In severe cases, the infection can spread to the central nervous system, causing meningitis, brain abscess, and sepsis.

Acute otitis externa is typically caused by Pseudomonas aeruginosa or Staphylococcus aureus, while chronic otitis externa can be caused by fungal infections such as Aspergillus or Candida albicans. Risk factors for otitis externa include eczema, psoriasis, dermatitis, acute otitis media, trauma to the ear canal, foreign bodies in the ear, water exposure, ear canal obstruction, and long-term antibiotic or steroid use.

Clinical features of otitis externa include itching of the ear canal, ear pain, tenderness of the tragus and/or pinna, ear discharge, hearing loss if the ear canal is completely blocked, redness and swelling of the ear canal, debris in the ear canal, and cellulitis of the pinna and adjacent skin. Tender regional lymphadenitis is uncommon.

Management of acute otitis externa involves general ear care measures, optimizing any underlying medical or skin conditions that are risk factors, avoiding the use of hearing aids or ear plugs if there is a suspected contact allergy, and avoiding the use of ear drops if there is a suspected allergy to any of its ingredients. Treatment options include over-the-counter acetic acid 2% ear drops or spray, aural toileting via dry swabbing, irrigation, or microsuction, and prescribing topical antibiotics with or without a topical corticosteroid. Oral antibiotics may be prescribed in severe cases or for immunocompromised individuals.

Follow-up is advised if symptoms do not improve within 48-72 hours of starting treatment, if symptoms have not fully resolved

Renal colic, also known as ureteric colic, refers to a sudden and intense pain in the lower back caused by a blockage in the ureter, which is the tube that carries urine from the kidney to the bladder. This condition is commonly associated with the presence of a urinary tract stone.

The main symptoms of renal or ureteric colic include severe abdominal pain on one side, starting in the lower back or flank and radiating to the groin or genital area in men, or to the labia in women. The pain comes and goes in spasms, lasting for minutes to hours, with periods of no pain or a dull ache. Nausea, vomiting, and the presence of blood in the urine are often accompanying symptoms.

People experiencing renal or ureteric colic are usually restless and unable to find relief by lying still, which helps to distinguish this condition from peritonitis. They may have a history of previous episodes and may also present with fever and sweating if there is an associated urinary infection. Some individuals may complain of painful urination, frequent urination, and straining when the stone reaches the junction between the ureter and the bladder, as the stone irritates the detrusor muscle.

In terms of pain management, the first-line treatment for adults, children, and young people with suspected renal colic is a non-steroidal anti-inflammatory drug (NSAID), which can be administered through various routes. If NSAIDs are contraindicated or not providing sufficient pain relief, intravenous paracetamol can be offered as an alternative. Opioids may be considered if both NSAIDs and intravenous paracetamol are contraindicated or not effective in relieving pain. Antispasmodics should not be given to individuals with suspected renal colic.

For more detailed information, you can refer to the NICE guidelines on the assessment and management of renal and ureteric stones.

Desmopressin, a common treatment for cranial diabetes insipidus (DI) following pituitary surgery, can often lead to hyponatremia as a side effect. Therefore, it is important for patients to have their electrolyte levels regularly monitored. Symptoms of hyponatremia may include nausea, vomiting, headache, confusion, lethargy, fatigue, restlessness, irritability, muscle weakness or spasms, seizures, and drowsiness (which can progress to coma in severe cases).

Further Reading:

Diabetes insipidus (DI) is a condition characterized by either a decrease in the secretion of antidiuretic hormone (cranial DI) or insensitivity to antidiuretic hormone (nephrogenic DI). Antidiuretic hormone, also known as arginine vasopressin, is produced in the hypothalamus and released from the posterior pituitary. The typical biochemical disturbances seen in DI include elevated plasma osmolality, low urine osmolality, polyuria, and hypernatraemia.

Cranial DI can be caused by various factors such as head injury, CNS infections, pituitary tumors, and pituitary surgery. Nephrogenic DI, on the other hand, can be genetic or result from electrolyte disturbances or the use of certain drugs. Symptoms of DI include polyuria, polydipsia, nocturia, signs of dehydration, and in children, irritability, failure to thrive, and fatigue.

To diagnose DI, a 24-hour urine collection is done to confirm polyuria, and U&Es will typically show hypernatraemia. High plasma osmolality with low urine osmolality is also observed. Imaging studies such as MRI of the pituitary, hypothalamus, and surrounding tissues may be done, as well as a fluid deprivation test to evaluate the response to desmopressin.

Management of cranial DI involves supplementation with desmopressin, a synthetic form of arginine vasopressin. However, hyponatraemia is a common side effect that needs to be monitored. In nephrogenic DI, desmopressin supplementation is usually not effective, and management focuses on ensuring adequate fluid intake to offset water loss and monitoring electrolyte levels. Causative drugs need to be stopped, and there is a risk of developing complications such as hydroureteronephrosis and an overdistended bladder.

During CPR of a hypothermic patient, it is important to follow specific guidelines. If the patient’s core temperature is below 30ºC, resuscitation drugs, such as adrenaline, should be withheld. Once the core temperature rises above 30ºC, cardiac arrest drugs can be administered. However, if the patient’s temperature is between 30-35ºC, the interval for administering cardiac arrest drugs should be doubled. For example, adrenaline should be given every 6-10 minutes instead of the usual 3-5 minutes for a normothermic patient.

Further Reading:

Hypothermic cardiac arrest is a rare situation that requires a tailored approach. Resuscitation is typically prolonged, but the prognosis for young, previously healthy individuals can be good. Hypothermic cardiac arrest may be associated with drowning. Hypothermia is defined as a core temperature below 35ºC and can be graded as mild, moderate, severe, or profound based on the core temperature. When the core temperature drops, basal metabolic rate falls and cell signaling between neurons decreases, leading to reduced tissue perfusion. Signs and symptoms of hypothermia progress as the core temperature drops, initially presenting as compensatory increases in heart rate and shivering, but eventually ceasing as the temperature drops into moderate hypothermia territory.

ECG changes associated with hypothermia include bradyarrhythmias, Osborn waves, prolonged PR, QRS, and QT intervals, shivering artifact, ventricular ectopics, and cardiac arrest. When managing hypothermic cardiac arrest, ALS should be initiated as per the standard ALS algorithm, but with modifications. It is important to check for signs of life, re-warm the patient, consider mechanical ventilation due to chest wall stiffness, adjust dosing or withhold drugs due to slowed drug metabolism, and correct electrolyte disturbances. The resuscitation of hypothermic patients is often prolonged and may continue for a number of hours.

Pulse checks during CPR may be difficult due to low blood pressure, and the pulse check is prolonged to 1 minute for this reason. Drug metabolism is slowed in hypothermic patients, leading to a build-up of potentially toxic plasma concentrations of administered drugs. Current guidance advises withholding drugs if the core temperature is below 30ºC and doubling the drug interval at core temperatures between 30 and 35ºC. Electrolyte disturbances are common in hypothermic patients, and it is important to interpret results keeping the setting in mind. Hypoglycemia should be treated, hypokalemia will often correct as the patient re-warms, ABG analyzers may not reflect the reality of the hypothermic patient, and severe hyperkalemia is a poor prognostic indicator.

Different warming measures can be used to increase the core body temperature, including external passive measures such as removal of wet clothes and insulation with blankets, external active measures such as forced heated air or hot-water immersion, and internal active measures such as inhalation of warm air, warmed intravenous fluids, gastric, bladder, peritoneal and/or pleural lavage and high volume renal haemofilter.

Type I hypersensitivity reactions, also known as allergic reactions, are triggered when a person is exposed again to a particular antigen, which is referred to as the allergen. These reactions are mediated by IgE and typically manifest within 15 to 30 minutes after exposure to the allergen. One common symptom of a type I hypersensitivity reaction is the rapid onset of a urticarial rash, which occurs shortly after coming into contact with the allergen, such as latex.

In the UK, the most commonly used treatment for acute exacerbations of hereditary angioedema (HAE) in emergency departments is C1-Esterase inhibitor. However, there are alternative options available. Icatibant acetate, sold under the brand name Firazyr®, is a bradykinin receptor antagonist that is licensed in the UK and Europe and can be used as an alternative treatment. Another alternative is the transfusion of fresh frozen plasma.

Further Reading:

Angioedema and urticaria are related conditions that involve swelling in different layers of tissue. Angioedema refers to swelling in the deeper layers of tissue, such as the lips and eyelids, while urticaria, also known as hives, refers to swelling in the epidermal skin layers, resulting in raised red areas of skin with itching. These conditions often coexist and may have a common underlying cause.

Angioedema can be classified into allergic and non-allergic types. Allergic angioedema is the most common type and is usually triggered by an allergic reaction, such as to certain medications like penicillins and NSAIDs. Non-allergic angioedema has multiple subtypes and can be caused by factors such as certain medications, including ACE inhibitors, or underlying conditions like hereditary angioedema (HAE) or acquired angioedema.

HAE is an autosomal dominant disease characterized by a deficiency of C1 esterase inhibitor. It typically presents in childhood and can be inherited or acquired as a result of certain disorders like lymphoma or systemic lupus erythematosus. Acquired angioedema may have similar clinical features to HAE but is caused by acquired deficiencies of C1 esterase inhibitor due to autoimmune or lymphoproliferative disorders.

The management of urticaria and allergic angioedema focuses on ensuring the airway remains open and addressing any identifiable triggers. In mild cases without airway compromise, patients may be advised that symptoms will resolve without treatment. Non-sedating antihistamines can be used for up to 6 weeks to relieve symptoms. Severe cases of urticaria may require systemic corticosteroids in addition to antihistamines. In moderate to severe attacks of allergic angioedema, intramuscular epinephrine may be considered.

The management of HAE involves treating the underlying deficiency of C1 esterase inhibitor. This can be done through the administration of C1 esterase inhibitor, bradykinin receptor antagonists, or fresh frozen plasma transfusion, which contains C1 inhibitor.

In summary, angioedema and urticaria are related conditions involving swelling in different layers of tissue. They can coexist and may have a common underlying cause. Management involves addressing triggers, using antihistamines, and in severe cases, systemic corticosteroids or other specific treatments for HAE.

Classical symptoms of a urinary tract infection (UTI) typically include dysuria, suprapubic tenderness, urgency, haematuria, increased frequency of micturition, and polyuria. The Scottish Intercollegiate Guidelines Network (SIGN) has developed comprehensive guidelines for the management of UTIs. According to these guidelines, if a patient presents with three or more classical UTI symptoms and is not pregnant, it is recommended to initiate empirical treatment with a three-day course of either trimethoprim or nitrofurantoin. For more detailed information, you can refer to the SIGN guidelines on the management of suspected bacterial urinary tract infection in adults.

Healthcare workers responding to contaminated casualties must prioritize their own safety by wearing appropriate personal protective equipment. This is crucial because secondary contamination can occur. Additionally, if working in contaminated areas, healthcare workers should maximize ventilation and use breathing equipment. Ensuring the safety of healthcare workers is essential as they cannot effectively help the casualties without it.

The first step in managing contaminated casualties is early skin decontamination. It is important to move the casualties to a safe area and remove all contaminated clothing to minimize further exposure. The skin should then be thoroughly rinsed with water to physically remove the nerve agent. After rinsing, it should be washed with an alkaline solution of soap and water or a 0.5% hypochlorite solution to chemically neutralize the nerve agent. To prevent ongoing absorption through the eyes, contact lenses should be removed and the eyes irrigated.

Resuscitation should be initiated using an ABCDE approach, and casualties should be supported and transferred to the hospital as quickly as possible. Ventilation may be necessary in some cases. Nerve agent antidote autoinjectors can be utilized, and the use of these should be guided by local policy for prehospital personnel.

A recent audit conducted by the Royal College of Emergency Medicine (RCEM) in 2018 revealed a concerning decline in the standards of pain management for children with fractured limbs in Emergency Departments (EDs). The audit found that the majority of patients experienced longer waiting times for pain relief compared to previous years. Shockingly, more than 1 in 10 children who presented with significant pain due to a limb fracture did not receive any pain relief at all.

To address this issue, the Agency for Health Care Policy and Research (AHCPR) in the USA recommends following the ABCs of pain management for all patients, including children. This approach involves regularly asking about pain, systematically assessing it, believing the patient and their family in their reports of pain and what relieves it, choosing appropriate pain control options, delivering interventions in a timely and coordinated manner, and empowering patients and their families to have control over their pain management.

The RCEM has established standards that require a child’s pain to be assessed within 15 minutes of their arrival at the ED. This is considered a fundamental standard. Various rating scales are available for assessing pain in children, with the choice depending on the child’s age and ability to use the scale. These scales include the Wong-Baker Faces Pain Rating Scale, Numeric rating scale, and Behavioural scale.

To ensure timely administration of analgesia to children in acute pain, the RCEM has set specific standards. These standards state that 100% of patients in severe pain should receive appropriate analgesia within 60 minutes of their arrival or triage, whichever comes first. Additionally, 75% should receive analgesia within 30 minutes, and 50% within 20 minutes.

Hyperkalaemia is when the level of potassium in the blood is higher than 5.5 mmol/l. It can be categorized as mild, moderate, or severe depending on the specific potassium levels. Mild hyperkalaemia is between 5.5-5.9 mmol/l, moderate hyperkalaemia is between 6.0-6.4 mmol/l, and severe hyperkalaemia is above 6.5 mmol/l. The most common cause of hyperkalaemia in renal failure, which can be acute or chronic. Other causes include acidosis, adrenal insufficiency, cell lysis, and excessive potassium intake.

Calcium is used to counteract the harmful effects of hyperkalaemia on the heart by stabilizing the cardiac cell membrane and preventing abnormal depolarization. It works quickly, usually within 15 minutes, but its effects are not long-lasting. Calcium is considered a first-line treatment for arrhythmias and significant ECG abnormalities caused by hyperkalaemia, such as widening of the QRS interval, loss of the P wave, and cardiac arrhythmias. However, arrhythmias are rare at potassium levels below 7.5 mmol/l.

It’s important to note that calcium does not lower the serum potassium level. Therefore, it should be used in conjunction with other therapies that actually help reduce potassium levels, such as insulin and salbutamol. If the pH is measured to be above 7.35 and the potassium level remains high despite nebulized salbutamol, the APLS guidelines recommend the administration of an insulin and glucose infusion.

Acute kidney injury (AKI), previously known as acute renal failure, is a sudden decline in kidney function. This results in the accumulation of waste products and disturbances in fluid and electrolyte balance. AKI can occur in individuals with previously normal kidney function or those with pre-existing kidney disease, known as acute-on-chronic kidney disease. It is a relatively common condition, with approximately 15% of adults admitted to hospitals in the UK developing AKI.

The causes of AKI can be categorized into pre-renal, intrinsic renal, and post-renal factors. The majority of AKI cases in the community are due to pre-renal causes, accounting for 90% of cases. These are often associated with conditions such as hypotension from sepsis or fluid depletion. Medications, particularly ACE inhibitors and NSAIDs, are also frequently implicated in AKI.

The table below summarizes the most common causes of AKI:

Pre-renal:
– Volume depletion (e.g., hemorrhage, severe vomiting or diarrhea, burns)
– Oedematous states (e.g., cardiac failure, liver cirrhosis, nephrotic syndrome)
– Hypotension (e.g., cardiogenic shock, sepsis, anaphylaxis)
– Cardiovascular conditions (e.g., severe cardiac failure, arrhythmias)
– Renal hypoperfusion: NSAIDs, COX-2 inhibitors, ACE inhibitors or ARBs, Abdominal aortic aneurysm
– Renal artery stenosis
– Hepatorenal syndrome

Intrinsic renal:
– Glomerular disease (e.g., glomerulonephritis, thrombosis, hemolytic-uremic syndrome)
– Tubular injury: acute tubular necrosis (ATN) following prolonged ischemia
– Acute interstitial nephritis due to drugs (e.g., NSAIDs), infection, or autoimmune diseases
– Vascular disease (e.g., vasculitis, polyarteritis nodosa, thrombotic microangiopathy, cholesterol emboli, renal vein thrombosis, malignant hypertension)
– Eclampsia

Post-renal:
– Renal stones
– Blood clot
– Papillary necrosis
– Urethral stricture
– Prostatic hypertrophy or malignancy
– Bladder tumor
– Radiation fibrosis
– Pelvic malignancy
– Retroperitoneal fibrosis

Epididymo-orchitis refers to the inflammation of the epididymis and/or testicle. It typically presents with sudden pain, swelling, and inflammation in the affected area. This condition can also occur chronically, which means that the pain and inflammation last for more than six months.

The causes of epididymo-orchitis vary depending on the age of the patient. In men under 35 years old, the infection is usually sexually transmitted and caused by Chlamydia trachomatis or Neisseria gonorrhoeae. In men over 35 years old, the infection is usually non-sexually transmitted and occurs as a result of enteric organisms that cause urinary tract infections, with Escherichia coli being the most common. However, there can be some overlap between these groups, so it is important to obtain a thorough sexual history in all age groups.

Mumps should also be considered as a potential cause of epididymo-orchitis in the 15 to 30 age group, as mumps orchitis occurs in around 40% of post-pubertal boys with mumps.

While most cases of epididymo-orchitis are infective, non-infectious causes can also occur. These include genito-urinary surgery, vasectomy, urinary catheterization, Behcet’s disease, sarcoidosis, and drug-induced cases such as those caused by amiodarone.

Patients with epididymo-orchitis typically present with unilateral scrotal pain and swelling that develops relatively quickly. The affected testis will be tender to touch, and there is usually a palpable swelling of the epididymis that starts at the lower pole of the testis and spreads towards the upper pole. The testis itself may also be involved, and there may be redness and/or swelling of the scrotum on the affected side. Patients may experience fever and urethral discharge as well.

The most important differential diagnosis to consider is testicular torsion, which requires immediate medical attention within 6 hours of onset to save the testicle. Testicular torsion is more likely in men under the age of 20, especially if the pain is very severe and sudden. It typically presents around four hours after onset. In this case, the patient’s age, longer history of symptoms, and the presence of fever are more indicative of epididymo-orchitis.

Based on the given information, the most likely diagnosis for the 4-year-old female patient is viral gastroenteritis. This is supported by the symptoms of vomiting and diarrhea, as well as the fact that the patient has been drinking less than usual and has vomited after being given a drink. The absence of recent travel and up-to-date immunizations also suggest that this is a viral rather than a bacterial infection.

Further Reading:

Gastroenteritis is a common condition in children, particularly those under the age of 5. It is characterized by the sudden onset of diarrhea, with or without vomiting. The most common cause of gastroenteritis in infants and young children is rotavirus, although other viruses, bacteria, and parasites can also be responsible. Prior to the introduction of the rotavirus vaccine in 2013, rotavirus was the leading cause of gastroenteritis in children under 5 in the UK. However, the vaccine has led to a significant decrease in cases, with a drop of over 70% in subsequent years.

Norovirus is the most common cause of gastroenteritis in adults, but it also accounts for a significant number of cases in children. In England & Wales, there are approximately 8,000 cases of norovirus each year, with 15-20% of these cases occurring in children under 9.

When assessing a child with gastroenteritis, it is important to consider whether there may be another more serious underlying cause for their symptoms. Dehydration assessment is also crucial, as some children may require intravenous fluids. The NICE traffic light system can be used to identify the risk of serious illness in children under 5.

In terms of investigations, stool microbiological testing may be indicated in certain cases, such as when the patient has been abroad, if diarrhea lasts for more than 7 days, or if there is uncertainty over the diagnosis. U&Es may be necessary if intravenous fluid therapy is required or if there are symptoms and/or signs suggestive of hypernatremia. Blood cultures may be indicated if sepsis is suspected or if antibiotic therapy is planned.

Fluid management is a key aspect of treating children with gastroenteritis. In children without clinical dehydration, normal oral fluid intake should be encouraged, and oral rehydration solution (ORS) supplements may be considered. For children with dehydration, ORS solution is the preferred method of rehydration, unless intravenous fluid therapy is necessary. Intravenous fluids may be required for children with shock or those who are unable to tolerate ORS solution.

Antibiotics are generally not required for gastroenteritis in children, as most cases are viral or self-limiting. However, there are some exceptions, such as suspected or confirmed sepsis, Extraintestinal spread of bacterial infection, or specific infections like Clostridium difficile-associated pseudomembranous enterocolitis or giardiasis.

Benzodiazepines are helpful in reducing shivering and improving the effectiveness of active cooling techniques. They are particularly useful in controlling seizures and making cooling more tolerable for patients. By administering small doses of intravenous benzodiazepines like diazepam or midazolam, shivering can be reduced, which in turn prevents heat gain and enhances the cooling process. On the other hand, dantrolene does not currently have any role in managing heat stroke. Additionally, antipyretics are not effective in reducing high body temperature caused by excessive heat. They only work when the core body temperature is elevated due to pyrogens.

Further Reading:

Heat Stroke:
– Core temperature >40°C with central nervous system dysfunction
– Classified into classic/non-exertional heat stroke and exertional heat stroke
– Classic heat stroke due to passive exposure to severe environmental heat
– Exertional heat stroke due to strenuous physical activity in combination with excessive environmental heat
– Mechanisms to reduce core temperature overwhelmed, leading to tissue damage
– Symptoms include high body temperature, vascular endothelial surface damage, inflammation, dehydration, and renal failure
– Management includes cooling methods and supportive care
– Target core temperature for cooling is 38.5°C

Heat Exhaustion:
– Mild to moderate heat illness that can progress to heat stroke if untreated
– Core temperature elevated but <40°C
– Symptoms include nausea, vomiting, dizziness, and mild neurological symptoms
– Normal thermoregulation is disrupted
– Management includes moving patient to a cooler environment, rehydration, and rest

Other Heat-Related Illnesses:
– Heat oedema: transitory swelling of hands and feet, resolves spontaneously
– Heat syncope: results from volume depletion and peripheral vasodilatation, managed by moving patient to a cooler environment and rehydration
– Heat cramps: painful muscle contractions associated with exertion, managed with cooling, rest, analgesia, and rehydration

Risk Factors for Severe Heat-Related Illness:
– Old age, very young age, chronic disease and debility, mental illness, certain medications, housing issues, occupational factors

Management:
– Cooling methods include spraying with tepid water, fanning, administering cooled IV fluids, cold or ice water immersion, and ice packs
– Benzodiazepines may be used to control shivering
– Rapid cooling to achieve rapid normothermia should be avoided to prevent overcooling and hypothermia
– Supportive care includes intravenous fluid replacement, seizure treatment if required, and consideration of haemofiltration
– Some patients may require liver transplant due to significant liver damage
– Patients with heat stroke should ideally be managed in a HDU/ICU setting with CVP and urinary catheter output measurements

The clinical manifestations of cannabis use encompass various aspects. Firstly, it can amplify pre-existing mood states, leading to feelings of euphoria, depression, or anxiety. Additionally, cannabis can distort one’s perception of time and space, creating a sense of disorientation. It also enhances the enjoyment of aesthetic experiences, making them more pleasurable. Visual hallucinations may also occur as a result of cannabis use. Physiological effects include dry mouth, coughing, and irritation of the respiratory tract. Furthermore, cannabis use often leads to an increased appetite and a decrease in body temperature. Reddened eyes and respiratory tract irritation are also common symptoms associated with cannabis use.

This patient is experiencing hyponatremia, which is characterized by low plasma osmolality and high urine osmolality, indicating syndrome of inappropriate antidiuretic hormone secretion (SIADH). One of the most common causes of SIADH is the use of SSRIs. On the other hand, lithium, sodium bicarbonate, and corticosteroids are known to cause hypernatremia. Plasma osmolality can be calculated using the formula (2 x Na) + Glucose + Urea. In this patient, the calculated osmolality is 265 mosmol/kg, which falls within the normal range of 275-295 mosmol/kg.

Further Reading:

Syndrome of inappropriate antidiuretic hormone (SIADH) is a condition characterized by low sodium levels in the blood due to excessive secretion of antidiuretic hormone (ADH). ADH, also known as arginine vasopressin (AVP), is responsible for promoting water and sodium reabsorption in the body. SIADH occurs when there is impaired free water excretion, leading to euvolemic (normal fluid volume) hypotonic hyponatremia.

There are various causes of SIADH, including malignancies such as small cell lung cancer, stomach cancer, and prostate cancer, as well as neurological conditions like stroke, subarachnoid hemorrhage, and meningitis. Infections such as tuberculosis and pneumonia, as well as certain medications like thiazide diuretics and selective serotonin reuptake inhibitors (SSRIs), can also contribute to SIADH.

The diagnostic features of SIADH include low plasma osmolality, inappropriately elevated urine osmolality, urinary sodium levels above 30 mmol/L, and euvolemic. Symptoms of hyponatremia, which is a common consequence of SIADH, include nausea, vomiting, headache, confusion, lethargy, muscle weakness, seizures, and coma.

Management of SIADH involves correcting hyponatremia slowly to avoid complications such as central pontine myelinolysis. The underlying cause of SIADH should be treated if possible, such as discontinuing causative medications. Fluid restriction is typically recommended, with a daily limit of around 1000 ml for adults. In severe cases with neurological symptoms, intravenous hypertonic saline may be used. Medications like demeclocycline, which blocks ADH receptors, or ADH receptor antagonists like tolvaptan may also be considered.

It is important to monitor serum sodium levels closely during treatment, especially if using hypertonic saline, to prevent rapid correction that can lead to central pontine myelinolysis. Osmolality abnormalities can help determine the underlying cause of hyponatremia, with increased urine osmolality indicating dehydration or renal disease, and decreased urine osmolality suggesting SIADH or overhydration.

Epididymo-orchitis refers to the inflammation of the epididymis and/or testicle. It typically presents with sudden pain, swelling, and inflammation in the affected area. This condition can also occur chronically, which means that the pain and inflammation last for more than six months.

The causes of epididymo-orchitis vary depending on the age of the patient. In men under 35 years old, the infection is usually sexually transmitted and caused by Chlamydia trachomatis or Neisseria gonorrhoeae. In men over 35 years old, the infection is usually non-sexually transmitted and occurs as a result of enteric organisms that cause urinary tract infections, with Escherichia coli being the most common. However, there can be some overlap between these groups, so it is important to obtain a thorough sexual history in all age groups.

Mumps should also be considered as a potential cause of epididymo-orchitis in the 15 to 30 age group, as mumps orchitis occurs in around 40% of post-pubertal boys with mumps.

While most cases of epididymo-orchitis are infective, non-infectious causes can also occur. These include genito-urinary surgery, vasectomy, urinary catheterization, Behcet’s disease, sarcoidosis, and drug-induced cases such as those caused by amiodarone.

Patients with epididymo-orchitis typically present with unilateral scrotal pain and swelling that develops relatively quickly. The affected testis will be tender to touch, and there is usually a palpable swelling of the epididymis that starts at the lower pole of the testis and spreads towards the upper pole. The testis itself may also be involved, and there may be redness and/or swelling of the scrotum on the affected side. Patients may experience fever and urethral discharge as well.

The most important differential diagnosis to consider is testicular torsion, which requires immediate medical attention within 6 hours of onset to save the testicle. Testicular torsion is more likely in men under the age of 20, especially if the pain is very severe and sudden. It typically presents around four hours after onset. In this case, the patient’s age, longer history of symptoms, and the presence of fever are more indicative of epididymo-orchitis.

To distinguish

Placental abruption, also known as abruptio placentae, occurs when the placental lining separates from the wall of the uterus before delivery and after 20 weeks of gestation.

In the early stages, there may be no symptoms, but typically abdominal pain and vaginal bleeding develop. Approximately 20% of patients experience a concealed placental abruption, where the haemorrhage is confined within the uterine cavity and the amount of blood loss can be significantly underestimated.

The clinical features of placental abruption include sudden onset abdominal pain (which can be severe), variable vaginal bleeding, severe or continuous contractions, abdominal tenderness, and an enlarged, tense uterus. The foetus often shows signs of distress, such as reduced movements, increased or decreased fetal heart rate, decreased variability of fetal heart rate, and late decelerations.

In contrast, placenta praevia is painless and the foetal heart is generally normal. The degree of obstetric shock is usually proportional to the amount of vaginal blood loss. Another clue that the cause of bleeding is placenta praevia rather than placental abruption is that the foetus may have an abnormal presentation or lie.

Lidocaine works by blocking voltage-gated sodium channels. These channels are responsible for the propagation of action potentials in nerve fibers. By blocking these channels, lidocaine prevents the influx of sodium ions into the nerve cells, thereby inhibiting the generation and conduction of nerve impulses. This results in local anesthesia, as the transmission of pain signals from the skin to the brain is effectively blocked.

Further Reading:

Local anaesthetics, such as lidocaine, bupivacaine, and prilocaine, are commonly used in the emergency department for topical or local infiltration to establish a field block. Lidocaine is often the first choice for field block prior to central line insertion. These anaesthetics work by blocking sodium channels, preventing the propagation of action potentials.

However, local anaesthetics can enter the systemic circulation and cause toxic side effects if administered in high doses. Clinicians must be aware of the signs and symptoms of local anaesthetic systemic toxicity (LAST) and know how to respond. Early signs of LAST include numbness around the mouth or tongue, metallic taste, dizziness, visual and auditory disturbances, disorientation, and drowsiness. If not addressed, LAST can progress to more severe symptoms such as seizures, coma, respiratory depression, and cardiovascular dysfunction.

The management of LAST is largely supportive. Immediate steps include stopping the administration of local anaesthetic, calling for help, providing 100% oxygen and securing the airway, establishing IV access, and controlling seizures with benzodiazepines or other medications. Cardiovascular status should be continuously assessed, and conventional therapies may be used to treat hypotension or arrhythmias. Intravenous lipid emulsion (intralipid) may also be considered as a treatment option.

If the patient goes into cardiac arrest, CPR should be initiated following ALS arrest algorithms, but lidocaine should not be used as an anti-arrhythmic therapy. Prolonged resuscitation may be necessary, and intravenous lipid emulsion should be administered. After the acute episode, the patient should be transferred to a clinical area with appropriate equipment and staff for further monitoring and care.

It is important to report cases of local anaesthetic toxicity to the appropriate authorities, such as the National Patient Safety Agency in the UK or the Irish Medicines Board in the Republic of Ireland. Additionally, regular clinical review should be conducted to exclude pancreatitis, as intravenous lipid emulsion can interfere with amylase or lipase assays.

The intravascular volume of an infant is approximately 80 ml/kg, while in older children it is around 70 ml/kg. Dehydration itself does not lead to death, but shock can. Shock can occur when there is a loss of 20 ml/kg from the intravascular space, whereas clinical dehydration is only noticeable after total losses greater than 25 ml/kg.

The table below summarizes the maintenance fluid requirements for well, normal children based on their body weight:

Bodyweight: First 10 kg
Daily fluid requirement: 100 ml/kg
Hourly fluid requirement: 4 ml/kg

Bodyweight: Second 10 kg
Daily fluid requirement: 50 ml/kg
Hourly fluid requirement: 2 ml/kg

Bodyweight: Subsequent kg
Daily fluid requirement: 20 ml/kg
Hourly fluid requirement: 1 ml/kg

In general, if a child shows clinical signs of dehydration without shock, they can be assumed to be 5% dehydrated. If shock is also present, it can be assumed that they are 10% dehydrated or more. 5% dehydration means that the body has lost 5 g per 100 g body weight, which is equivalent to 50 ml/kg of fluid. Therefore, 10% dehydration implies a loss of 100 ml/kg of fluid.

In the case of this child, they are in shock and should receive a 20 ml/kg fluid bolus. Therefore, the initial volume of fluid to administer should be 20 x 8 ml = 160 ml.

The clinical features of dehydration and shock are summarized in the table below:

Dehydration (5%):
– Appears ‘unwell’
– Normal heart rate or tachycardia
– Normal respiratory rate or tachypnea
– Normal peripheral pulses
– Normal or mildly prolonged capillary refill time (CRT)
– Normal blood pressure
– Warm extremities
– Decreased urine output
– Reduced skin turgor
– Sunken eyes
– Depressed fontanelle
– Dry mucous membranes

Clinical shock (10%):
– Pale, lethargic, mottled appearance
– Tachycardia
– Tachypnea
– Weak peripheral pulses
– Prolonged capillary refill time (CRT)
– Hypotension
– Cold extremities
– Decreased urine output
– Decreased level of consciousness

The administration of nitrous oxide increases the amount of inhaled anaesthetic gases in the body through a phenomenon called the ‘second gas effect’. Nitrous oxide is much more soluble than nitrogen, with a solubility that is 20 to 30 times higher. When nitrous oxide is given, it causes a decrease in the volume of air in the alveoli. Additionally, nitrous oxide can enhance the absorption of other inhaled anaesthetic agents through the second gas effect. However, it is important to note that nitrous oxide alone cannot be used as the sole maintenance agent in anaesthesia.

Further Reading:

Entonox® is a mixture of 50% nitrous oxide and 50% oxygen that can be used for self-administration to reduce anxiety. It can also be used alongside other anesthesia agents. However, its mechanism of action for anxiety reduction is not fully understood. The Entonox bottles are typically identified by blue and white color-coded collars, but a new standard will replace these with dark blue shoulders in the future. It is important to note that Entonox alone cannot be used as the sole maintenance agent in anesthesia.

One of the effects of nitrous oxide is the second-gas effect, where it speeds up the absorption of other inhaled anesthesia agents. Nitrous oxide enters the alveoli and diffuses into the blood, displacing nitrogen. This displacement causes the remaining alveolar gases to become more concentrated, increasing the fractional content of inhaled anesthesia gases and accelerating the uptake of volatile agents into the blood.

However, when nitrous oxide administration is stopped, it can cause diffusion hypoxia. Nitrous oxide exits the blood and diffuses back into the alveoli, while nitrogen diffuses in the opposite direction. Nitrous oxide enters the alveoli much faster than nitrogen leaves, resulting in the dilution of oxygen within the alveoli. This can lead to diffusion hypoxia, where the oxygen concentration in the alveoli is diluted, potentially causing oxygen deprivation in patients breathing air.

There are certain contraindications for using nitrous oxide, as it can expand in air-filled spaces. It should be avoided in conditions such as head injuries with intracranial air, pneumothorax, recent intraocular gas injection, and entrapped air following a recent underwater dive.

The following provides a summary of common causes for different acid-base disorders.

Respiratory alkalosis can be caused by hyperventilation, such as during periods of anxiety. It can also be a result of conditions like pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, or the early stages of aspirin overdose.

Respiratory acidosis, on the other hand, is often associated with chronic obstructive pulmonary disease (COPD), life-threatening asthma, pulmonary edema, sedative drug overdose (such as opiates or benzodiazepines), neuromuscular disease, obesity, or other respiratory conditions.

Metabolic alkalosis can occur due to vomiting, potassium depletion (often caused by diuretic usage), Cushing’s syndrome, or Conn’s syndrome.

Metabolic acidosis with a raised anion gap can be caused by lactic acidosis (such as in cases of hypoxemia, shock, sepsis, or infarction), ketoacidosis (such as in diabetes, starvation, or alcohol excess), renal failure, or poisoning (such as in late stages of aspirin overdose, methanol or ethylene glycol ingestion).

Lastly, metabolic acidosis with a normal anion gap can be a result of conditions like diarrhea, ammonium chloride ingestion, or adrenal insufficiency.

NSAIDs are known to have a relaxing effect on the ureter, but a randomized controlled trial found no difference between NSAIDs and a placebo in terms of this effect. Currently, only two classes of drugs, calcium channel blockers and alpha-blockers, are considered effective as medical expulsive therapy (MET). Calcium channel blockers work by blocking the active calcium channel pump that the smooth muscle of the ureter uses to contract, resulting in relaxation of the muscle and improved stone passage. Alpha-blockers, on the other hand, are commonly used as the first-line treatment to enhance stone passage. They reduce the basal tone of the ureter smooth muscle, decrease the frequency of peristaltic waves, and lower ureteric contraction. This leads to a decrease in intraureteric pressure below the stone, increasing the chances of stone passage. Patients treated with calcium channel blockers or alpha-blockers have been shown to have a 65% higher likelihood of spontaneous stone passage compared to those not given these medications.