Radial nerve injuries often occur in conjunction with fractures of the humerus. The most common cause of a radial nerve palsy is external compression or trauma to the radial nerve as it passes through the spiral groove in the middle of the humerus.

There are several factors that can lead to damage of the radial nerve in the spiral groove. These include trauma, such as a fracture in the middle of the humerus, compression known as Saturday night palsy, and iatrogenic causes like injections.

When the radial nerve is injured within the spiral groove, it results in weakness of the wrist and metacarpophalangeal joints. However, elbow extension is not affected because the branches to the triceps and anconeus muscles originate before the spiral groove. The interphalangeal joints remain unaffected as well, as they are supplied by the median and ulnar nerves. Sensory loss will be experienced over the dorsal aspect of the forearm, extending from below the elbow to the 1st dorsal interosseous.

In contrast, injury to the radial nerve in the axilla will also cause weakness of elbow extension and sensory loss in the distribution of the more proximal cutaneous branches. This helps distinguish it from injury in the spiral groove.

In the forearm, the posterior interosseous branch of the radial nerve can also be damaged. This can occur due to injury to the radial head or entrapment in the supinator muscle under the arcade of Frohse. However, this type of injury can be easily distinguished from injury in the spiral groove because there is no sensory involvement and no wrist drop, thanks to the preservation of the extensor carpi radialis longus. Nonetheless, there will still be weakness in the wrist and fingers.

It is recommended to obtain an arterial blood gas (ABG) sample from all patients who have experienced submersion (drowning) as even individuals without symptoms may have a surprising level of hypoxia. Draining the lungs is not effective and not recommended. There is no strong evidence to support the routine use of antibiotics as a preventive measure. Steroids have not been proven to be effective in treating drowning. All drowning patients, except those with normal oxygen levels, normal saturations, and normal lung sounds, should receive supplemental oxygen as significant hypoxia can occur without causing difficulty in breathing.

Further Reading:

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

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

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

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

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

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

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

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Anaphylaxis is a type I hypersensitivity reaction, where the body’s response is triggered by the attachment of an antigen to a specific antibody. This attachment then leads to the release of histamine and other mediators, such as leukotrienes, tumor necrosis factor, and various cytokines, from mast cells and basophils. These substances are released when these cells are exposed to the antigen.

When there is damage to the facial nerve in the LMN, the patient will experience paralysis in the forehead and will be unable to wrinkle their brow. However, in an upper motor neuron lesion, the frontalis muscle is not affected, so the patient can still furrow their brow normally and their ability to close their eyes and blink is not affected. Lower motor neuron lesions affect the final part of the nerve pathway to all branches of the facial nerve, resulting in paralysis of the forehead and the rest of the face on that side. It is important to note that the speed of onset may provide some clues about the cause of the lesion, but it does not help determine the specific location of the damage.

Further Reading:

Bell’s palsy is a condition characterized by sudden weakness or paralysis of the facial nerve, resulting in facial muscle weakness or drooping. The exact cause is unknown, but it is believed to be related to viral infections such as herpes simplex or varicella zoster. It is more common in individuals aged 15-45 years and those with diabetes, obesity, hypertension, or upper respiratory conditions. Pregnancy is also a risk factor.

Diagnosis of Bell’s palsy is typically based on clinical symptoms and ruling out other possible causes of facial weakness. Symptoms include rapid onset of unilateral facial muscle weakness, drooping of the eyebrow and corner of the mouth, loss of the nasolabial fold, otalgia, difficulty chewing or dry mouth, taste disturbance, eye symptoms such as inability to close the eye completely, dry eye, eye pain, and excessive tearing, numbness or tingling of the cheek and mouth, speech articulation problems, and hyperacusis.

When assessing a patient with facial weakness, it is important to consider other possible differentials such as stroke, facial nerve tumors, Lyme disease, granulomatous diseases, Ramsay Hunt syndrome, mastoiditis, and chronic otitis media. Red flags for these conditions include insidious and painful onset, duration of symptoms longer than 3 months with frequent relapses, pre-existing risk factors, systemic illness or fever, vestibular or hearing abnormalities, and other cranial nerve involvement.

Management of Bell’s palsy involves the use of steroids, eye care advice, and reassurance. Steroids, such as prednisolone, are recommended for individuals presenting within 72 hours of symptom onset. Eye care includes the use of lubricating eye drops, eye ointment at night, eye taping if unable to close the eye at night, wearing sunglasses, and avoiding dusty environments. Reassurance is important as the majority of patients make a complete recovery within 3-4 months. However, some individuals may experience sequelae such as facial asymmetry, gustatory lacrimation, inadequate lid closure, brow ptosis, drooling, and hemifacial spasms.

Antiviral treatments are not currently recommended as a standalone treatment for Bell’s palsy, but they may be given in combination with corticosteroids on specialist advice. Referral to an ophthalmologist is necessary if the patient has eye symptoms such as pain, irritation, or itch.

Delirium is characterized by fluctuating symptoms of disturbed consciousness that typically develop over hours to days. During the day, lucid intervals may occur, while the worst disturbances are often experienced at night. In contrast, dementia has a gradual onset and does not involve fluctuations in mental state. Stroke, on the other hand, is associated with focal neurological deficits.

Further Reading:

Delirium is an acute syndrome that causes disturbances in consciousness, attention, cognition, and perception. It is also known as an acute confusional state. The DSM-IV criteria for diagnosing delirium include recent onset of fluctuating awareness, impairment of memory and attention, and disorganized thinking. Delirium typically develops over hours to days and may be accompanied by behavioral changes, personality changes, and psychotic features. It often occurs in individuals with predisposing factors, such as advanced age or multiple comorbidities, when exposed to new precipitating factors, such as medications or infection. Symptoms of delirium fluctuate throughout the day, with lucid intervals occurring during the day and worse disturbances at night. Falling and loss of appetite are often warning signs of delirium.

Delirium can be classified into three subtypes based on the person’s symptoms. Hyperactive delirium is characterized by inappropriate behavior, hallucinations, and agitation. Restlessness and wandering are common in this subtype. Hypoactive delirium is characterized by lethargy, reduced concentration, and appetite. The person may appear quiet or withdrawn. Mixed delirium presents with signs and symptoms of both hyperactive and hypoactive subtypes.

The exact pathophysiology of delirium is not fully understood, but it is believed to involve multiple mechanisms, including cholinergic deficiency, dopaminergic excess, and inflammation. The cause of delirium is usually multifactorial, with predisposing factors and precipitating factors playing a role. Predisposing factors include older age, cognitive impairment, frailty, significant injuries, and iatrogenic events. Precipitating factors include infection, metabolic or electrolyte disturbances, cardiovascular disorders, respiratory disorders, neurological disorders, endocrine disorders, urological disorders, gastrointestinal disorders, severe uncontrolled pain, alcohol intoxication or withdrawal, medication use, and psychosocial factors.

Delirium is highly prevalent in hospital settings, affecting up to 50% of inpatients aged over 65 and occurring in 30% of people aged over 65 presenting to the emergency department. Complications of delirium include increased risk of death, high in-hospital mortality rates, higher mortality rates following hospital discharge, increased length of stay in hospital, nosocomial infections, increased risk of admission to long-term care or re-admission to hospital, increased incidence of dementia, increased risk of falls and associated injuries, pressure sores.

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 flank or loin area and radiating to the groin or testicle 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.

The pain experienced during renal or ureteric colic is often described as the most intense pain a person has ever felt, with many women comparing it to the pain of childbirth. Restlessness and an inability to find relief by lying still are common signs, which can help differentiate renal colic from peritonitis. Previous episodes of similar pain may also be reported by the individual. In cases where there is a concomitant urinary infection, fever and sweating may be present. Additionally, the person 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.

It is important to seek urgent medical attention if certain conditions are met. These include signs of systemic infection or sepsis, such as fever or sweating, or if the person is at a higher risk of acute kidney injury, such as having pre-existing chronic kidney disease, a solitary or transplanted kidney, or suspected bilateral obstructing stones. Hospital admission is also necessary if the person is dehydrated and unable to consume fluids orally due to nausea and/or vomiting. If there is uncertainty regarding the diagnosis, it is recommended to consult further resources, such as the NICE guidelines on the assessment and management of renal and ureteric stones.

The risk of contracting meningococcal disease from a close contact is low. However, the risk is highest within the first seven days after the disease is diagnosed and decreases significantly afterwards.

Prophylaxis or vaccination for close contacts is typically organized by secondary care. It is recommended for the following individuals, regardless of their meningococcal vaccination status:

– People who have had prolonged close contact with the infected person in a household-type setting during the seven days prior to the onset of illness. This includes individuals living or sleeping in the same household, students in the same dormitory, partners, or university students sharing a kitchen in a hall of residence.

– People who have had brief close contact with the infected person, but only if they have been directly exposed to large particle droplets or secretions from the respiratory tract of the case around the time of admission to the hospital.

Antibiotic prophylaxis should be administered as soon as possible, ideally within 24 hours after the diagnosis of the index case.

Post-exposure prophylaxis is recommended for healthcare staff who have been exposed to direct nasopharyngeal secretions (without wearing a mask or personal protective equipment) from a known or highly probable case. This includes situations such as mouth-to-mouth resuscitation, airway management (suction/intubation), or prolonged close care within 1 meter of the patient who has been coughing or sneezing droplet secretions.

For more information, you can refer to the NICE Clinical Knowledge Summary on the management of close contacts of patients with meningococcal disease.

Atopic dermatitis is a long-lasting inflammatory skin condition that is linked to increased levels of IgE in the bloodstream. It is also characterized by sensitivity to various allergens found in the air, food, and microorganisms.

Further Reading:

Eczema is a chronic inflammatory skin disease characterized by dry, itchy skin with eczematous lesions. It often follows a chronic relapsing course and can lead to chronic skin changes such as lichenification and pigment changes. The term eczema is often used interchangeably with dermatitis, but strictly speaking, dermatitis refers to inflammation of the skin while eczema refers to specific conditions where skin inflammation is a feature.

Atopic eczema, also known as atopic dermatitis, is the most common type of eczema. It is usually first diagnosed in young children, with 90% of cases diagnosed before the age of 5. However, it can affect individuals of any age. Symptoms often improve as patients progress into their teens and adulthood. Around 10-20% of children are affected by atopic eczema, but only 3% of adults experience symptoms.

The exact cause of atopic eczema is not fully understood, but it is believed to be multifactorial, with both genetic and environmental factors playing a role. Genetic defects in genes that aid in the functioning of the skin barrier have been identified, which may predispose individuals to breaks in the skin barrier and increased exposure to antigens. Environmental factors such as pollution, allergen exposure, climate, and others also contribute to the development of the disease.

Diagnosing atopic eczema involves assessing the presence of key clinical features, such as pruritus (itching), eczema/dermatitis in a pattern appropriate for age, early age of onset, and personal or family history of atopy. Various diagnostic criteria have been established to aid in the diagnosis, including those set out by the American Academy of Dermatology and the UK working party.

The severity of atopic eczema can vary, and treatment options depend on the severity. Mild cases may be managed with emollients (moisturizers) and mild potency topical corticosteroids. Moderate cases may require moderate potency topical corticosteroids, topical calcineurin inhibitors, and bandages. Severe cases may necessitate the use of potent topical corticosteroids, topical calcineurin inhibitors, bandages, phototherapy, and systemic therapy.

In addition to medical treatment, identifying and avoiding triggers is an important aspect of managing atopic eczema. Common triggers include irritants, contact allergens, certain foods, skin infections, inhalant triggers, stress and infection.

Triage is a crucial process that involves determining the priority of patients’ treatment based on the severity of their condition and their chances of recovery. Its purpose is to ensure that limited resources are used efficiently, maximizing the number of lives saved. During a major incident, primary triage takes place in the bronze area, which is located within the inner cordon.

In the context of a major incident, priorities are assigned numbers from 1 to 3, with 1 being the highest priority. These priorities are also color-coded for easy identification:
– P1: Immediate priority. This category includes patients who require immediate life-saving intervention to prevent death. They are color-coded red.
– P2: Intermediate priority. Patients in this group also require significant interventions, but their treatment can be delayed for a few hours. They are color-coded yellow.
– P3: Delayed priority. Patients in this category require medical treatment, but it can be safely delayed. This category also includes walking wounded individuals. The classification as P3 is based on the motor score of the Glasgow Coma Scale, which predicts a favorable outcome. They are color-coded green.

The fourth classification is for deceased individuals. It is important to identify and classify them to prevent the unnecessary use of limited resources on those who cannot be helped. Dead bodies should be left in their current location, both to avoid wasting resources and because the area may be considered a crime scene. Deceased individuals are color-coded black.

The ROME IV criteria are utilized in secondary care to diagnose IBS, as recommended by NICE. The DSM-5 criteria are employed in diagnosing various mental health disorders. Coeliac disease diagnosis involves the use of modified marsh typing. Gastro-oesophageal reflux disease diagnosis relies on the Lyon Consensus.

Further Reading:

Irritable bowel syndrome (IBS) is a chronic disorder that affects the interaction between the gut and the brain. The exact cause of IBS is not fully understood, but factors such as genetics, drug use, enteric infections, diet, and psychosocial factors are believed to play a role. The main symptoms of IBS include abdominal pain, changes in stool form and/or frequency, and bloating. IBS can be classified into subtypes based on the predominant stool type, including diarrhea-predominant, constipation-predominant, mixed, and unclassified.

Diagnosing IBS involves using the Rome IV criteria, which includes recurrent abdominal pain associated with changes in stool frequency and form. It is important to rule out other more serious conditions that may mimic IBS through a thorough history, physical examination, and appropriate investigations. Treatment for IBS primarily involves diet and lifestyle modifications. Patients are advised to eat regular meals with a healthy, balanced diet and adjust their fiber intake based on symptoms. A low FODMAP diet may be trialed, and a dietician may be consulted for guidance. Regular physical activity and weight management are also recommended.

Psychosocial factors, such as stress, anxiety, and depression, should be addressed and managed appropriately. If constipation is a predominant symptom, soluble fiber supplements or foods high in soluble fiber may be recommended. Laxatives can be considered if constipation persists, and linaclotide may be tried if optimal doses of previous laxatives have not been effective. Antimotility drugs like loperamide can be used for diarrhea, and antispasmodic drugs or low-dose tricyclic antidepressants may be prescribed for abdominal pain. If symptoms persist or are refractory to treatment, alternative diagnoses should be considered, and referral to a specialist may be necessary.

Overall, the management of IBS should be individualized based on the patient’s symptoms and psychosocial situation. Clear explanation of the condition and providing resources for patient education, such as the NHS patient information leaflet and support from organizations like The IBS Network, can also be beneficial.

The second heart sound (S2) is created by vibrations produced when the aortic and pulmonary valves close. It marks the end of systole. It is normal to hear a split in the sound during inspiration.

A loud S2 can be associated with certain conditions such as systemic hypertension (resulting in a loud A2), pulmonary hypertension (resulting in a loud P2), hyperdynamic states (like tachycardia, fever, or thyrotoxicosis), and atrial septal defect (which causes a loud P2).

On the other hand, a soft S2 can be linked to decreased aortic diastolic pressure (as seen in aortic regurgitation), poorly mobile cusps (such as calcification of the aortic valve), aortic root dilatation, and pulmonary stenosis (which causes a soft P2).

A widely split S2 can occur during deep inspiration, right bundle branch block, prolonged right ventricular systole (seen in conditions like pulmonary stenosis or pulmonary embolism), and severe mitral regurgitation. However, in the case of atrial septal defect, the splitting is fixed and does not vary with respiration.

Reversed splitting of S2, where P2 occurs before A2 (paradoxical splitting), can occur during deep expiration, left bundle branch block, prolonged left ventricular systole (as seen in hypertrophic cardiomyopathy), severe aortic stenosis, and right ventricular pacing.

The standard facial X-ray series consists of two occipitomental x-rays: the Occipitomental (or Occipitomental 15º) and the Occipitomental 30º. The Occipitomental view captures the upper and middle thirds of the face, showing important structures such as the orbital margins, frontal sinuses, zygomatic arches, and maxillary antra. On the other hand, the Occipitomental 30º view uses a 30º caudal angulation, resulting in a less clear visualization of the orbits but a clearer view of the zygomatic arches and the walls of the maxillary antra.

Further Reading:

Zygomatic injuries, also known as zygomatic complex fractures, involve fractures of the zygoma bone and often affect surrounding bones such as the maxilla and temporal bones. These fractures can be classified into four positions: the lateral and inferior orbital rim, the zygomaticomaxillary buttress, and the zygomatic arch. The full extent of these injuries may not be visible on plain X-rays and may require a CT scan for accurate diagnosis.

Zygomatic fractures can pose risks to various structures in the face. The temporalis muscle and coronoid process of the mandible may become trapped in depressed fractures of the zygomatic arch. The infraorbital nerve, which passes through the infraorbital foramen, can be injured in zygomaticomaxillary complex fractures. In orbital floor fractures, the inferior rectus muscle may herniate into the maxillary sinus.

Clinical assessment of zygomatic injuries involves observing facial asymmetry, depressed facial bones, contusion, and signs of eye injury. Visual acuity must be assessed, and any persistent bleeding from the nose or mouth should be noted. Nasal injuries, including septal hematoma, and intra-oral abnormalities should also be evaluated. Tenderness of facial bones and the temporomandibular joint should be assessed, along with any step deformities or crepitus. Eye and jaw movements must also be evaluated.

Imaging for zygomatic injuries typically includes facial X-rays, such as occipitomental views, and CT scans for a more detailed assessment. It is important to consider the possibility of intracranial hemorrhage and cervical spine injury in patients with facial fractures.

Management of most zygomatic fractures can be done on an outpatient basis with maxillofacial follow-up, assuming the patient is stable and there is no evidence of eye injury. However, orbital floor fractures should be referred immediately to ophthalmologists or maxillofacial surgeons. Zygomatic arch injuries that restrict mouth opening or closing due to entrapment of the temporalis muscle or mandibular condyle also require urgent referral. Nasal fractures, often seen in conjunction with other facial fractures, can be managed by outpatient ENT follow-up but should be referred urgently if there is uncontrolled epistaxis, CSF rhinorrhea, or septal hematoma.

Intubation is rarely necessary for asthmatic patients, with only about 2% of asthma attacks requiring it. Most severe cases can be managed using non-invasive ventilation techniques. However, intubation can be a life-saving measure for asthmatic patients in critical condition. The indications for intubation include severe hypoxia, altered mental state, failure to respond to medications or non-invasive ventilation, and respiratory or cardiac arrest.

Before intubation, it is important to preoxygenate the patient and administer intravenous fluids. Nasal oxygen during intubation can provide additional time. Intravenous fluids are crucial because patients with acute asthma exacerbations can experience significant fluid loss, which can lead to severe hypotension during intubation and positive pressure ventilation.

There is no perfect combination of drugs for rapid sequence induction (RSI), but ketamine is often the preferred choice. Ketamine has bronchodilatory properties and does not cause hypotension as a side effect. Propofol can also be used, but it carries a risk of hypotension. In some cases, a subdissociative dose of ketamine can be helpful to facilitate the use of non-invasive ventilation in a hypoxic or combative patient.

Rocuronium and suxamethonium are commonly used as paralytic agents. Rocuronium has the advantage of providing a longer period of paralysis, which helps avoid ventilator asynchrony in the early stages of management.

Proper mechanical ventilation is essential, and it involves allowing the patient enough time to fully exhale the delivered breath and prevent hyperinflation. Therefore, permissive hypercapnia is typically used, and the ventilator settings should be adjusted accordingly. The recommended settings are a respiratory rate of 6-8 breaths per minute and a tidal volume of 6 ml per kilogram of body weight.

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

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

Renal disease is not commonly seen as a presenting sign or symptom, but approximately a certain percentage of individuals may develop it. In the case of meningococcal septicaemia, patients usually experience acute illness along with abnormal observations and confusion. Immune thrombocytopenia (ITP) is known to cause easy bruising and nosebleeds, but it does not have the same distribution pattern as HSP and does not come with abdominal pain or joint pain. On the other hand, viral urticaria and roseola typically result in a rash that blanches.

Further Reading:

Henoch-Schonlein purpura (HSP) is a small vessel vasculitis that is mediated by IgA. It is commonly seen in children following an infection, with 90% of cases occurring in children under 10 years of age. The condition is characterized by a palpable purpuric rash, abdominal pain, gastrointestinal upset, and polyarthritis. Renal involvement occurs in approximately 50% of cases, with renal impairment typically occurring within 1 day to 1 month after the onset of other symptoms. However, renal impairment is usually mild and self-limiting, although 10% of cases may have serious renal impairment at presentation and 1% may progress to end-stage kidney failure long term. Treatment for HSP involves analgesia for arthralgia, and treatment for nephropathy is generally supportive. The prognosis for HSP is usually excellent, with the condition typically resolving fully within 4 weeks, especially in children without renal involvement. However, around 1/3rd of patients may experience relapses, which can occur for several months.

Anticholinergic drugs have been found to worsen cognitive impairment in individuals with dementia. Certain commonly prescribed medications are associated with a higher anticholinergic burden, which can lead to increased cognitive decline. Examples of drugs with high anticholinergic potency include tricyclic antidepressants like amitriptyline hydrochloride, paroxetine, first-generation antihistamines such as chlorpheniramine maleate and promethazine hydrochloride, certain antipsychotics like olanzapine, clozapine, and quetiapine, urinary antispasmodics like solifenacin, oxybutynin, and tolterodine, and antimuscarinics like ipratropium, tiotropium, atropine, and cyclopentolate. However, it’s important to note that rivastigmine and memantine are recommended as first-line treatments for Alzheimer’s and DLB, while haloperidol, despite being an antipsychotic, has low anticholinergic potency.

Further Reading:

Dementia is a progressive and irreversible clinical syndrome characterized by cognitive and behavioral symptoms. These symptoms include memory loss, impaired reasoning and communication, personality changes, and reduced ability to carry out daily activities. The decline in cognition affects multiple domains of intellectual functioning and is not solely due to normal aging.

To diagnose dementia, a person must have impairment in at least two cognitive domains that significantly impact their daily activities. This impairment cannot be explained by delirium or other major psychiatric disorders. Early-onset dementia refers to dementia that develops before the age of 65.

The most common cause of dementia is Alzheimer’s disease, accounting for 50-75% of cases. Other causes include vascular dementia, dementia with Lewy bodies, and frontotemporal dementia. Less common causes include Parkinson’s disease dementia, Huntington’s disease, prion disease, and metabolic and endocrine disorders.

There are several risk factors for dementia, including age, mild cognitive impairment, genetic predisposition, excess alcohol intake, head injury, depression, learning difficulties, diabetes, obesity, hypertension, smoking, Parkinson’s disease, low social engagement, low physical activity, low educational attainment, hearing impairment, and air pollution.

Assessment of dementia involves taking a history from the patient and ideally a family member or close friend. The person’s current level of cognition and functional capabilities should be compared to their baseline level. Physical examination, blood tests, and cognitive assessment tools can also aid in the diagnosis.

Differential diagnosis for dementia includes normal age-related memory changes, mild cognitive impairment, depression, delirium, vitamin deficiencies, hypothyroidism, adverse drug effects, normal pressure hydrocephalus, and sensory deficits.

Management of dementia involves a multi-disciplinary approach that includes non-pharmacological and pharmacological measures. Non-pharmacological interventions may include driving assessment, modifiable risk factor management, and non-pharmacological therapies to promote cognition and independence. Drug treatments for dementia should be initiated by specialists and may include acetylcholinesterase inhibitors, memantine, and antipsychotics in certain cases.

In summary, dementia is a progressive and irreversible syndrome characterized by cognitive and behavioral symptoms. It has various causes and risk factors, and its management involves a multi-disciplinary approach.

The management of anaphylaxis involves several important steps. First and foremost, it is crucial to ensure proper airway management. Additionally, early administration of adrenaline is essential, preferably in the anterolateral aspect of the middle third of the thigh. Aggressive fluid resuscitation is also necessary. In severe cases, intubation may be required. However, it is important to note that the administration of chlorpheniramine and hydrocortisone should only be considered after early resuscitation has taken place.

Adrenaline is the most vital medication for treating anaphylactic reactions. It acts as an alpha-adrenergic receptor agonist, which helps reverse peripheral vasodilatation and reduce oedema. Furthermore, its beta-adrenergic effects aid in dilating the bronchial airways, increasing the force of myocardial contraction, and suppressing histamine and leukotriene release. Administering adrenaline as the first drug is crucial, and the intramuscular (IM) route is generally the most effective for most individuals.

The recommended doses of IM adrenaline for different age groups during anaphylaxis are as follows:

– Children under 6 years: 150 mcg (0.15 mL of 1:1000)
– Children aged 6-12 years: 300 mcg (0.3 mL of 1:1000)
– Children older than 12 years: 500 mcg (0.5 mL of 1:1000)
– Adults: 500 mcg (0.5 mL of 1:1000)

The patient’s history aligns with a generalized tonic-clonic seizure. The observer of the incident provided a detailed description, which is crucial in diagnosing epilepsy.

Diagnosing epilepsy can sometimes rely solely on the patient’s history. It is common to ask the patient to maintain a seizure diary to identify patterns and potential triggers. Additionally, EEG tests, along with an MRI scan or CT scan of the brain, can provide further insight into the type and possible cause of the seizures.

Recognizing the extent of blood loss based on vital sign and mental status abnormalities is a crucial skill. The Advanced Trauma Life Support (ATLS) classification for hemorrhagic shock correlates the amount of blood loss with expected physiological responses in a healthy individual weighing 70 kg. In terms of body weight, the total circulating blood volume accounts for approximately 7%, which is roughly equivalent to five liters in an average 70 kg male patient.

The ATLS classification for hemorrhagic shock is as follows:

CLASS I:
– Blood loss: Up to 750 mL
– Blood loss (% blood volume): Up to 15%
– Pulse rate: Less than 100 beats per minute (bpm)
– Systolic blood pressure: Normal
– Pulse pressure: Normal (or increased)
– Respiratory rate: 14-20 breaths per minute
– Urine output: Greater than 30 mL/hr
– CNS/mental status: Slightly anxious

CLASS II:
– Blood loss: 750-1500 mL
– Blood loss (% blood volume): 15-30%
– Pulse rate: 100-120 bpm
– Systolic blood pressure: Normal
– Pulse pressure: Decreased
– Respiratory rate: 20-30 breaths per minute
– Urine output: 20-30 mL/hr
– CNS/mental status: Mildly anxious

CLASS III:
– Blood loss: 1500-2000 mL
– Blood loss (% blood volume): 30-40%
– Pulse rate: 120-140 bpm
– Systolic blood pressure: Decreased
– Pulse pressure: Decreased
– Respiratory rate: 30-40 breaths per minute
– Urine output: 5-15 mL/hr
– CNS/mental status: Anxious, confused

CLASS IV:
– Blood loss: More than 2000 mL
– Blood loss (% blood volume): More than 40%
– Pulse rate: More than 140 bpm
– Systolic blood pressure: Decreased
– Pulse pressure: Decreased
– Respiratory rate: More than 40 breaths per minute
– Urine output: Negligible
– CNS/mental status: Confused, lethargic

Thyroid storm, also known as thyrotoxic crisis, is a rare and dangerous complication of hyperthyroidism. The initial management of this condition involves the use of specific medications. These medications include a beta blocker, a corticosteroid, an antithyroid drug, and an iodine solution.

The beta blocker used is typically propranolol, which is administered intravenously at a dose of 1 mg over 1 minute. If a beta blocker is contraindicated, a calcium channel blocker such as diltiazem may be used instead, at a dose of 0.25 mg/kg over 2 minutes.

For corticosteroids, hydrocortisone is commonly used and given intravenously at a dose of 200 mg. Alternatively, dexamethasone can be used at a dose of 2 mg intravenously.

The antithyroid drug used is usually propylthiouracil, which is given orally, through a nasogastric tube, or rectally, at a dose of 200 mg.

An iodine solution, specifically Lugol’s iodine, is also part of the initial management. However, it should not be administered until at least 1 hour after the antithyroid drug has been given. This is because iodine can exacerbate thyrotoxicosis by stimulating thyroid hormone synthesis. Propylthiouracil, on the other hand, inhibits the normal interactions of iodine and peroxidase with thyroglobulin, preventing the formation of T4 and T3. Therefore, it is given first and allowed time to take effect before iodine is administered.

Further Reading:

The thyroid gland is an endocrine organ located in the anterior neck. It consists of two lobes connected by an isthmus. The gland produces hormones called thyroxine (T4) and triiodothyronine (T3), which regulate energy use, protein synthesis, and the body’s sensitivity to other hormones. The production of T4 and T3 is stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland, which is in turn stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.

Thyroid disorders can occur when there is an imbalance in the production or regulation of thyroid hormones. Hypothyroidism is characterized by a deficiency of thyroid hormones, while hyperthyroidism is characterized by an excess. The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. It is more common in women and is often associated with goiter. Other causes include subacute thyroiditis, atrophic thyroiditis, and iodine deficiency. On the other hand, the most common cause of hyperthyroidism is Graves’ disease, which is also an autoimmune disorder. Other causes include toxic multinodular goiter and subacute thyroiditis.

The symptoms and signs of thyroid disorders can vary depending on whether the thyroid gland is underactive or overactive. In hypothyroidism, common symptoms include weight gain, lethargy, cold intolerance, and dry skin. In hyperthyroidism, common symptoms include weight loss, restlessness, heat intolerance, and increased sweating. Both hypothyroidism and hyperthyroidism can also affect other systems in the body, such as the cardiovascular, gastrointestinal, and neurological systems.

Complications of thyroid disorders can include dyslipidemia, metabolic syndrome, coronary heart disease, heart failure, subfertility and infertility, impaired special senses, and myxedema coma in severe cases of hypothyroidism. In hyperthyroidism, complications can include Graves’ orbitopathy, compression of the esophagus or trachea by goiter, thyrotoxic periodic paralysis, arrhythmias, osteoporosis, mood disorders, and increased obstetric complications.

Myxedema coma is a rare and life-threatening complication of severe hypothyroidism. It can be triggered by factors such as infection or physiological insult and presents with lethargy, bradycardia, hypothermia, hypotension, hypoventilation, altered mental state, seizures and/or coma.

The tricuspid valve is the most commonly affected valve in cases of infective endocarditis among intravenous drug users. This means that when IV drug users develop infective endocarditis, it is most likely to affect the tricuspid valve. On the other hand, in cases of native valve endocarditis and prosthetic valve endocarditis, the mitral valve is the valve that is most commonly affected.

Further Reading:

Infective endocarditis (IE) is an infection that affects the innermost layer of the heart, known as the endocardium. It is most commonly caused by bacteria, although it can also be caused by fungi or viruses. IE can be classified as acute, subacute, or chronic depending on the duration of illness. Risk factors for IE include IV drug use, valvular heart disease, prosthetic valves, structural congenital heart disease, previous episodes of IE, hypertrophic cardiomyopathy, immune suppression, chronic inflammatory conditions, and poor dental hygiene.

The epidemiology of IE has changed in recent years, with Staphylococcus aureus now being the most common causative organism in most industrialized countries. Other common organisms include coagulase-negative staphylococci, streptococci, and enterococci. The distribution of causative organisms varies depending on whether the patient has a native valve, prosthetic valve, or is an IV drug user.

Clinical features of IE include fever, heart murmurs (most commonly aortic regurgitation), non-specific constitutional symptoms, petechiae, splinter hemorrhages, Osler’s nodes, Janeway’s lesions, Roth’s spots, arthritis, splenomegaly, meningism/meningitis, stroke symptoms, and pleuritic pain.

The diagnosis of IE is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Major criteria include positive blood cultures with typical microorganisms and positive echocardiogram findings. Minor criteria include fever, vascular phenomena, immunological phenomena, and microbiological phenomena. Blood culture and echocardiography are key tests for diagnosing IE.

In summary, infective endocarditis is an infection of the innermost layer of the heart that is most commonly caused by bacteria. It can be classified as acute, subacute, or chronic and can be caused by a variety of risk factors. Staphylococcus aureus is now the most common causative organism in most industrialized countries. Clinical features include fever, heart murmurs, and various other symptoms. The diagnosis is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Blood culture and echocardiography are important tests for diagnosing IE.

Theophylline, a medication commonly used to treat respiratory conditions, can be affected by certain drugs, either increasing or decreasing its plasma concentration and half-life. Drugs that can increase the plasma concentration of theophylline include calcium channel blockers like verapamil, cimetidine, fluconazole, macrolides such as erythromycin, methotrexate, and quinolones like ciprofloxacin. On the other hand, drugs like carbamazepine, phenobarbitol, phenytoin (and fosphenytoin), rifampicin, and St. John’s wort can decrease the plasma concentration of theophylline. It is important to be aware of these interactions when prescribing or taking theophylline to ensure its effectiveness and avoid potential side effects.

The symptoms and signs of strokes can vary depending on which blood vessel is affected. Here is a summary of the main symptoms based on the territory affected:

Anterior cerebral artery: This can cause weakness on the opposite side of the body, with the leg and shoulder being more affected than the arm, hand, and face. There may also be minimal loss of sensation on the opposite side of the body. Other symptoms can include difficulty speaking (dysarthria), language problems (aphasia), apraxia (difficulty with limb movements), urinary incontinence, and changes in behavior and personality.

Middle cerebral artery: This can lead to weakness on the opposite side of the body, with the face and arm being more affected than the leg. There may also be a loss of sensation on the opposite side of the body. Depending on the dominant hemisphere of the brain, there may be difficulties with expressive or receptive language (dysphasia). In the non-dominant hemisphere, there may be neglect of the opposite side of the body.

Posterior cerebral artery: This can cause a loss of vision on the opposite side of both eyes (homonymous hemianopia). There may also be defects in a specific quadrant of the visual field. In some cases, there may be a syndrome affecting the thalamus on the opposite side of the body.

It’s important to note that these are just general summaries and individual cases may vary. If you suspect a stroke, it’s crucial to seek immediate medical attention.

Calcium-channel blocker overdose is a serious matter and should be regarded as potentially life-threatening. Verapamil and diltiazem are the two most dangerous types of calcium channel blockers when taken in excess. They work by attaching to the alpha-1 subunit of L-type calcium channels, which stops calcium from entering the cells. These channels play a crucial role in the functioning of cardiac myocytes, vascular smooth muscle cells, and islet beta-cells.

Clostridium difficile (C.diff) is a gram positive rod commonly found in hospitals. Some strains of C.diff produce exotoxins that can cause intestinal damage, leading to pseudomembranous colitis. This infection can range from mild diarrhea to severe illness. Antibiotic-associated diarrhea is often caused by C.diff, with 20-30% of cases being attributed to this bacteria. Antibiotics such as clindamycin, cephalosporins, fluoroquinolones, and broad-spectrum penicillins are frequently associated with C.diff infection.

Clinical features of C.diff infection include diarrhea, distinctive smell, abdominal pain, raised white blood cell count, and in severe cases, toxic megacolon. In some severe cases, diarrhea may be absent due to the infection causing paralytic ileus. Diagnosis is made by detecting Clostridium difficile toxin (CDT) in the stool. There are two types of exotoxins produced by C.diff, toxin A and toxin B, which cause mucosal damage and the formation of a pseudomembrane in the colon.

Risk factors for developing C.diff infection include age over 65, antibiotic treatment, previous C.diff infection, exposure to infected individuals, proton pump inhibitor or H2 receptor antagonist use, prolonged hospitalization or residence in a nursing home, and chronic disease or immunosuppression. Complications of C.diff infection can include toxic megacolon, colon perforation, sepsis, and even death, especially in frail elderly individuals.

Management of C.diff infection involves stopping the causative antibiotic if possible, optimizing hydration with IV fluids if necessary, and assessing the severity of the infection. Treatment options vary based on severity, ranging from no antibiotics for mild cases to vancomycin or fidaxomicin for moderate cases, and hospital protocol antibiotics (such as oral vancomycin with IV metronidazole) for severe or life-threatening cases. Severe cases may require admission under gastroenterology or GI surgeons.

Diabetes insipidus (DI) is characterized by specific biochemical markers. One of these markers is a low urine osmolality, meaning that the concentration of solutes in the urine is lower than normal. In contrast, the serum osmolality, which measures the concentration of solutes in the blood, is high in individuals with DI. This combination of low urine osmolality and high serum osmolality is indicative of DI. Other common biochemical disturbances associated with DI include elevated plasma osmolality, polyuria (excessive urine production), and hypernatremia (high sodium levels in the blood). However, it is important to note that sodium levels can sometimes be within the normal range in individuals with DI. It is worth mentioning that conditions such as Addison’s disease, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and primary polydipsia are associated with low serum osmolality and hyponatremia. Additionally, the use of selective serotonin reuptake inhibitors (SSRIs) can also lead to hyponatremia as a side effect.

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.

This presentation strongly indicates a diagnosis of whooping cough, also known as pertussis. Whooping cough is a respiratory infection caused by the bacteria Bordetella pertussis. It is transmitted through respiratory droplets and has an incubation period of about 7-21 days. The disease is highly contagious and can be transmitted to around 90% of close household contacts.

The clinical course of whooping cough can be divided into two stages. The first stage is called the catarrhal stage, which resembles a mild respiratory infection with low-grade fever and symptoms similar to a cold. A cough may be present, but it is usually mild and not as severe as in the second stage. The catarrhal stage typically lasts for about a week.

The second stage is known as the paroxysmal stage. During this stage, the characteristic paroxysmal cough develops as the symptoms from the catarrhal stage start to improve. The coughing occurs in spasms, often preceded by an inspiratory whoop sound, followed by a series of rapid coughs. Vomiting may occur, and patients may develop subconjunctival hemorrhages and petechiae. Patients generally feel well between coughing spasms, and there are usually no abnormal chest findings. This stage can last up to 3 months, with a gradual recovery over this period. The later stages of this stage are sometimes referred to as the convalescent stage.

Complications of whooping cough can include secondary pneumonia, rib fractures, pneumothorax, hernias, syncopal episodes, encephalopathy, and seizures. It is important to note that a history of vaccination does not guarantee immunity, as it only provides about 95% protection.

The presence of marked lymphocytosis in this case also supports a diagnosis of pertussis, as it is a common finding. A lymphocyte count greater than 20 x 109/l is highly suggestive of the disease.

Dantrolene works by blocking the release of calcium ions from the sarcoplasmic reticulum in skeletal muscle cells. This reduces the amount of calcium available to bind to troponin on actin filaments, which in turn decreases the muscle’s ability to contract and reduces energy usage.

Further Reading:

Malignant hyperthermia is a rare and life-threatening syndrome that can be triggered by certain medications in individuals who are genetically susceptible. The most common triggers are suxamethonium and inhalational anaesthetic agents. The syndrome is caused by the release of stored calcium ions from skeletal muscle cells, leading to uncontrolled muscle contraction and excessive heat production. This results in symptoms such as high fever, sweating, flushed skin, rapid heartbeat, and muscle rigidity. It can also lead to complications such as acute kidney injury, rhabdomyolysis, and metabolic acidosis. Treatment involves discontinuing the trigger medication, administering dantrolene to inhibit calcium release and promote muscle relaxation, and managing any associated complications such as hyperkalemia and acidosis. Referral to a malignant hyperthermia center for further investigation is also recommended.

If a patient with a zygoma fracture experiences visual disturbance, limited eye movements (especially upward gaze), or shows a teardrop sign on a facial X-ray, it is important to refer them urgently to ophthalmology or maxillofacial surgeons.

Further Reading:

Zygomatic injuries, also known as zygomatic complex fractures, involve fractures of the zygoma bone and often affect surrounding bones such as the maxilla and temporal bones. These fractures can be classified into four positions: the lateral and inferior orbital rim, the zygomaticomaxillary buttress, and the zygomatic arch. The full extent of these injuries may not be visible on plain X-rays and may require a CT scan for accurate diagnosis.

Zygomatic fractures can pose risks to various structures in the face. The temporalis muscle and coronoid process of the mandible may become trapped in depressed fractures of the zygomatic arch. The infraorbital nerve, which passes through the infraorbital foramen, can be injured in zygomaticomaxillary complex fractures. In orbital floor fractures, the inferior rectus muscle may herniate into the maxillary sinus.

Clinical assessment of zygomatic injuries involves observing facial asymmetry, depressed facial bones, contusion, and signs of eye injury. Visual acuity must be assessed, and any persistent bleeding from the nose or mouth should be noted. Nasal injuries, including septal hematoma, and intra-oral abnormalities should also be evaluated. Tenderness of facial bones and the temporomandibular joint should be assessed, along with any step deformities or crepitus. Eye and jaw movements must also be evaluated.

Imaging for zygomatic injuries typically includes facial X-rays, such as occipitomental views, and CT scans for a more detailed assessment. It is important to consider the possibility of intracranial hemorrhage and cervical spine injury in patients with facial fractures.

Management of most zygomatic fractures can be done on an outpatient basis with maxillofacial follow-up, assuming the patient is stable and there is no evidence of eye injury. However, orbital floor fractures should be referred immediately to ophthalmologists or maxillofacial surgeons. Zygomatic arch injuries that restrict mouth opening or closing due to entrapment of the temporalis muscle or mandibular condyle also require urgent referral. Nasal fractures, often seen in conjunction with other facial fractures, can be managed by outpatient ENT follow-up but should be referred urgently if there is uncontrolled epistaxis, CSF rhinorrhea, or septal hematoma.