Kaposi’s sarcoma (KS) is a type of cancer that affects the connective tissues. It is caused by a virus called human herpesvirus 8 (HHV-8). This cancer is more likely to occur in individuals with weakened immune systems, such as those with HIV or those who have undergone organ transplants.

The main symptom of KS is the development of skin lesions. These lesions initially appear as red-purple spots and quickly progress to become raised bumps and nodules. They can appear on any part of the body, but are most commonly found on the lower limbs, back, face, mouth, and genital area.

Generally speaking, if a child shows clinical signs of dehydration but does not exhibit shock, it can be assumed that they are 5% dehydrated. On the other hand, if shock is also present, it can be assumed that the child is 10% dehydrated or more. When we say 5% dehydration, it means that the body has lost 5 grams of fluid per 100 grams of body weight, which is equivalent to 50 ml of fluid per kilogram. Similarly, 10% dehydration implies a fluid loss of 100 ml per kilogram of body weight.

In the case of this child, who is 5% dehydrated, we can estimate that she has lost 50 ml of fluid per kilogram. Considering her weight of 8 kilograms, her estimated fluid loss would be 400 ml.

The clinical features of dehydration and shock are summarized below:

Dehydration (5%):
– The child 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

Homonymous quadrantanopias occur when there are lesions in the optic radiation. The optic tract passes through the posterolateral angle of the optic chiasm, running alongside the cerebral peduncle and inside the uncus of the temporal lobe. Eventually, it reaches the lateral geniculate body (LGN) in the thalamus. Acting as a relay center, the LGN sends axons through the optic radiation to the primary visual cortex in the occipital lobe. The upper optic radiation carries fibers from the superior retinal quadrants (which corresponds to the lower half of the visual field) and travels through the parietal lobe. On the other hand, the lower optic radiation carries fibers from the inferior retinal quadrants (which corresponds to the upper half of the visual field) and travels through the temporal lobe. Consequently, lesions in the temporal lobe can lead to superior homonymous quadrantanopias, while lesions in the parietal lobe can cause inferior homonymous quadrantanopias. The diagram below provides a summary of the different visual field defects resulting from lesions at various points in the visual pathway.

High Altitude Cerebral Edema (HACE) is a condition that develops from acute mountain sickness (AMS). Ataxia, which refers to a lack of coordination, is the primary early indication of HACE. The mentioned symptoms are typical characteristics of AMS.

Further Reading:

High Altitude Illnesses

Altitude & Hypoxia:
– As altitude increases, atmospheric pressure decreases and inspired oxygen pressure falls.
– Hypoxia occurs at altitude due to decreased inspired oxygen.
– At 5500m, inspired oxygen is approximately half that at sea level, and at 8900m, it is less than a third.

Acute Mountain Sickness (AMS):
– AMS is a clinical syndrome caused by hypoxia at altitude.
– Symptoms include headache, anorexia, sleep disturbance, nausea, dizziness, fatigue, malaise, and shortness of breath.
– Symptoms usually occur after 6-12 hours above 2500m.
– Risk factors for AMS include previous AMS, fast ascent, sleeping at altitude, and age <50 years old.
– The Lake Louise AMS score is used to assess the severity of AMS.
– Treatment involves stopping ascent, maintaining hydration, and using medication for symptom relief.
– Medications for moderate to severe symptoms include dexamethasone and acetazolamide.
– Gradual ascent, hydration, and avoiding alcohol can help prevent AMS.

High Altitude Pulmonary Edema (HAPE):
– HAPE is a progression of AMS but can occur without AMS symptoms.
– It is the leading cause of death related to altitude illness.
– Risk factors for HAPE include rate of ascent, intensity of exercise, absolute altitude, and individual susceptibility.
– Symptoms include dyspnea, cough, chest tightness, poor exercise tolerance, cyanosis, low oxygen saturations, tachycardia, tachypnea, crepitations, and orthopnea.
– Management involves immediate descent, supplemental oxygen, keeping warm, and medication such as nifedipine.

High Altitude Cerebral Edema (HACE):
– HACE is thought to result from vasogenic edema and increased vascular pressure.
– It occurs 2-4 days after ascent and is associated with moderate to severe AMS symptoms.
– Symptoms include headache, hallucinations, disorientation, confusion, ataxia, drowsiness, seizures, and manifestations of raised intracranial pressure.
– Immediate descent is crucial for management, and portable hyperbaric therapy may be used if descent is not possible.
– Medication for treatment includes dexamethasone and supplemental oxygen. Acetazolamide is typically used for prophylaxis.

This patient has presented with an Addisonian crisis, which is a rare but potentially catastrophic condition if not diagnosed promptly. The most likely underlying rheumatological diagnosis in this case is polymyalgia rheumatica, and it is likely that the GP started the patient on prednisolone medication.

Addison’s disease occurs when the adrenal glands underproduce steroid hormones, affecting the production of glucocorticoids, mineralocorticoids, and sex steroids. The main causes of Addison’s disease include autoimmune adrenalitis (accounting for 80% of cases), bilateral adrenalectomy, Waterhouse-Friderichsen syndrome (hemorrhage into the adrenal glands), and tuberculosis.

An Addisonian crisis is most commonly triggered by the deliberate or accidental withdrawal of steroid therapy in patients with Addison’s disease. Other factors that can precipitate a crisis include infection, trauma, myocardial infarction, cerebral infarction, asthma, hypothermia, and alcohol abuse.

The clinical features of Addison’s disease include weakness, lethargy, hypotension (especially orthostatic hypotension), nausea, vomiting, weight loss, reduced axillary and pubic hair, depression, and hyperpigmentation (particularly in palmar creases, buccal mucosa, and exposed areas). In an Addisonian crisis, the main features are usually hypoglycemia and shock, characterized by tachycardia, peripheral vasoconstriction, hypotension, altered consciousness, and coma.

Biochemically, Addison’s disease is characterized by increased ACTH levels (as a compensatory response to stimulate the adrenal glands), elevated serum renin levels, hyponatremia, hyperkalemia, hypercalcemia, hypoglycemia, and metabolic acidosis. Diagnostic investigations may include the Synacthen test, plasma ACTH level, plasma renin level, and adrenocortical antibodies.

Management of Addison’s disease should be overseen by an Endocrinologist. Typically, patients require hydrocortisone, fludrocortisone, and dehydroepiandrosterone. Some patients may also need thyroxine if there is hypothalamic-pituitary disease present. Treatment is lifelong, and patients should carry a steroid card and a MedicAlert bracelet, being aware of the possibility of an Addisonian crisis.

The co-epidemic of tuberculosis and HIV is a significant global health challenge at present. According to the WHO, there were 10 million new cases of tuberculosis in 2019, with approximately 11% of these cases being co-infected with HIV. Tuberculosis is the most common contagious infection in individuals with compromised immune systems due to HIV, often leading to death.

Tuberculosis is caused by an infection with the bacterium Mycobacterium tuberculosis. While it primarily affects the lungs, it can also impact various other parts of the body. The disease is spread through aerosol transmission, meaning it is transmitted through droplets in the air.

The primary symptoms of tuberculosis infection include a chronic cough, coughing up blood (haemoptysis), fever, night sweats, and weight loss. In individuals who have not been previously affected, tuberculosis can cause a primary lesion known as the Ghon focus. This lesion typically develops in the upper lobes of the lungs.

In 15-20% of cases, the infection spreads to extrapulmonary sites such as the pleura, central nervous system, lymphatics, bones, joints, and genitourinary system. Extrapulmonary tuberculosis that affects the spine is known as Pott’s disease, primarily affecting the lower thoracic and upper lumbar vertebrae. Cervical tuberculous lymphadenopathy, also known as scrofula, is characterized by cold abscesses without erythema or warmth.

Only a small percentage of patients, around 5-10%, go on to develop post-primary tuberculosis, also known as reactivation tuberculosis. This typically occurs a year or two after the primary infection and is more likely to happen in individuals with a weakened immune system. Reactivation tuberculosis often involves the lung apex.

The main indications for thoracotomy in patients with haemothorax are prompt drainage of at least 1500 ml of blood, ongoing blood loss of more than 200 ml per hour for 2-4 hours, and the need for continued blood transfusion. Option 3 in the given choices meets these criteria as the blood loss remains above 200 ml per hour for more than 2 hours after the drain is inserted. Option 1 does not meet the criteria as the blood volume is below 1500 ml. Option 2 does not meet the criteria as the blood loss has not been ongoing for at least 2 hours. Option 4 does not meet the criteria as there is no information indicating the need for ongoing blood transfusion.

Further Reading:

Haemothorax is the accumulation of blood in the pleural cavity of the chest, usually resulting from chest trauma. It can be difficult to differentiate from other causes of pleural effusion on a chest X-ray. Massive haemothorax refers to a large volume of blood in the pleural space, which can impair physiological function by causing blood loss, reducing lung volume for gas exchange, and compressing thoracic structures such as the heart and IVC.

The management of haemothorax involves replacing lost blood volume and decompressing the chest. This is done through supplemental oxygen, IV access and cross-matching blood, IV fluid therapy, and the insertion of a chest tube. The chest tube is connected to an underwater seal and helps drain the fluid, pus, air, or blood from the pleural space. In cases where there is prompt drainage of a large amount of blood, ongoing significant blood loss, or the need for blood transfusion, thoracotomy and ligation of bleeding thoracic vessels may be necessary. It is important to have two IV accesses prior to inserting the chest drain to prevent a drop in blood pressure.

In summary, haemothorax is the accumulation of blood in the pleural cavity due to chest trauma. Managing haemothorax involves replacing lost blood volume and decompressing the chest through various interventions, including the insertion of a chest tube. Prompt intervention may be required in cases of significant blood loss or ongoing need for blood transfusion.

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 of 100 ml/kg, hourly fluid requirement of 4 ml/kg
– Second 10 kg: Daily fluid requirement of 50 ml/kg, hourly fluid requirement of 2 ml/kg
– Subsequent kg: Daily fluid requirement of 20 ml/kg, hourly fluid requirement of 1 ml/kg

In general, a child showing clinical signs of dehydration without shock is assumed to be 5% dehydrated. If shock is also present, it is assumed that the child is 10% dehydrated or more. 5% dehydration means 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 this case, the child is in shock and should receive a 20 ml/kg fluid bolus. The initial volume of fluid to administer should be 20 x 25% ml = 500 ml.

Following this, the child requires:
– 100 ml/kg replacement for the 10% dehydration = 100 x 25 = 2500 ml
– 1st 10 kg = 100 ml/kg for daily maintenance fluid = 100 x 10 = 1000 ml
– 2nd 10kg = 50 ml/kg for daily maintenance fluid = 50 x 10 = 500 ml
– Subsequent kg = 20 ml/kg for daily maintenance fluid = 20 x 5 = 100 ml

The total fluid needed for rehydration and maintenance is 2500 + 1600 = 4100 ml over a 24-hour period.

The clinical features of dehydration are summarized below:

Dehydration (5%):
– Appears ‘unwell’
– Normal heart rate or tachycardia
– Normal respiratory rate or tachypnea
– Normal peripheral pulses
– Normal or mildly prolonged

Methaemoglobinaemia is a condition that can occur when prilocaine is used, particularly when administered at doses higher than 16 mg/kg.

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 size of the cannula used for IV fluid infusion determines the maximum flow rate. For a 20g cannula, the maximum flow rate is around 60 ml per minute. As a result, the fastest infusion time through a 20g cannula is approximately 15 minutes for a maximum volume of 1000 ml.

Further Reading:

Peripheral venous cannulation is a procedure that should be performed following established guidelines to minimize the risk of infection, injury, extravasation, and early failure of the cannula. It is important to maintain good hand hygiene, use personal protective equipment, ensure sharps safety, and employ an aseptic non-touch technique during the procedure.

According to the National Institute for Health and Care Excellence (NICE), the skin should be disinfected with a solution of 2% chlorhexidine gluconate and 70% alcohol before inserting the catheter. It is crucial to allow the disinfectant to completely dry before inserting the cannula.

The flow rates of IV cannulas can vary depending on factors such as the gauge, color, type of fluid used, presence of a bio-connector, length of the cannula, and whether the fluid is drained under gravity or pumped under pressure. However, the following are typical flow rates for different gauge sizes: 14 gauge (orange) has a flow rate of 270 ml/minute, 16 gauge (grey) has a flow rate of 180 ml/minute, 18 gauge (green) has a flow rate of 90 ml/minute, 20 gauge (pink) has a flow rate of 60 ml/minute, and 22 gauge (blue) has a flow rate of 36 ml/minute. These flow rates are based on infusing 1000 ml of normal saline under ideal circumstances, but they may vary in practice.

The earliest and most common clinical indication of malignant hyperthermia is typically an increase in end tidal CO2 levels.

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.

Le Fort fractures are complex fractures of the midface that involve the maxillary bone and surrounding structures. These fractures can occur in a horizontal, pyramidal, or transverse direction. The distinguishing feature of Le Fort fractures is the traumatic separation of the pterygomaxillary region. They make up approximately 10% to 20% of all facial fractures and can have severe consequences, both in terms of potential life-threatening injuries and disfigurement.

The Le Fort classification system categorizes midface fractures into three groups based on the plane of injury. As the classification level increases, the location of the maxillary fracture moves from inferior to superior within the maxilla.

Le Fort I fractures are horizontal fractures that occur across the lower aspect of the maxilla. These fractures cause the teeth to separate from the upper face and extend through the lower nasal septum, the lateral wall of the maxillary sinus, and into the palatine bones and pterygoid plates. They are sometimes referred to as a floating palate because they often result in the mobility of the hard palate from the midface. Common accompanying symptoms include facial swelling, loose teeth, dental fractures, and misalignment of the teeth.

Le Fort II fractures are pyramidal-shaped fractures, with the base of the pyramid located at the level of the teeth and the apex at the nasofrontal suture. The fracture line extends from the nasal bridge and passes through the superior wall of the maxilla, the lacrimal bones, the inferior orbital floor and rim, and the anterior wall of the maxillary sinus. These fractures are sometimes called a floating maxilla because they typically result in the mobility of the maxilla from the midface. Common symptoms include facial swelling, nosebleeds, subconjunctival hemorrhage, cerebrospinal fluid leakage from the nose, and widening and flattening of the nasal bridge.

Le Fort III fractures are transverse fractures of the midface. The fracture line passes through the nasofrontal suture, the maxillo frontal suture, the orbital wall, and the zygomatic arch and zygomaticofrontal suture. These fractures cause separation of all facial bones from the cranial base, earning them the nickname craniofacial disjunction or floating face fractures. They are the rarest and most severe type of Le Fort fracture. Common symptoms include significant facial swelling, bruising around the eyes, facial flattening, and the entire face can be shifted.

Thiazide diuretics, like bendroflumethiazide and hydrochlorothiazide, have the potential to raise levels of uric acid in the blood, which can worsen gout symptoms in individuals who are susceptible to the condition.

Other medications, such as diuretics, beta-blockers, ACE inhibitors, and non-losartan ARBs, are also linked to an increased risk of gout.

On the other hand, calcium-channel blockers like amlodipine and verapamil, as well as losartan, have been found to lower uric acid levels and are associated with a reduced risk of gout.

A pilonidal sinus is a small cyst found near the crease between the buttocks. It contains a clump of hairs and is most commonly seen in young males with thick, dark hair. This condition is rare in individuals over the age of 40. Several factors increase the risk of developing a pilonidal sinus, including being male, having excessive hair growth, having a job that involves prolonged sitting, being overweight, and having a family history of the condition.

Early assessment of the airway is a critical aspect of managing a burned patient. Airway obstruction can occur rapidly due to direct injury or swelling from the burn. If there is a history of trauma, the airway should be evaluated while maintaining cervical spine control.

There are several risk factors for airway obstruction in burned patients, including inhalation injury, soot in the mouth or nostrils, singed nasal hairs, burns to the head, face, and neck, burns inside the mouth, large burn area and increasing burn depth, associated trauma, and a carboxyhemoglobin level above 10%.

In cases where significant swelling is anticipated, it may be necessary to urgently secure the airway with an uncut endotracheal tube before the swelling becomes severe. Delaying recognition of impending airway obstruction can make intubation difficult, and a surgical airway may be required.

The American Burn Life Support (ABLS) guidelines recommend early intubation in certain situations. These include signs of airway obstruction, extensive burns, deep facial burns, burns inside the mouth, significant swelling or risk of swelling, difficulty swallowing, respiratory compromise, decreased level of consciousness, and anticipated transfer of a patient with a large burn and airway issues without qualified personnel to intubate during transport.

Circumferential burns of the neck can cause tissue swelling around the airway, making early intubation necessary in these cases as well.

This explanation suggests that the patient’s symptoms are consistent with a case of travellers diarrhoea, which is in line with their medical history. GBS typically occurs within 1-3 weeks after the initial viral or bacterial infection that caused it.

Further Reading:

Campylobacter jejuni is a common cause of gastrointestinal infections, particularly travellers diarrhoea. It is a gram-negative bacterium that appears as curved rods. The infection is transmitted through the feco-oral route, often through the ingestion of contaminated meat, especially poultry. The incubation period for Campylobacter jejuni is typically 1-7 days, and the illness usually lasts for about a week.

The main symptoms of Campylobacter jejuni infection include watery, and sometimes bloody, diarrhea accompanied by abdominal cramps, fever, malaise, and headache. In some cases, complications can arise from the infection. Guillain-Barre syndrome (GBS) is one such complication that is associated with Campylobacter jejuni. Approximately 30% of GBS cases are caused by this bacterium.

When managing Campylobacter jejuni infection, conservative measures are usually sufficient, with a focus on maintaining hydration. However, in cases where symptoms are severe, such as high fever, bloody diarrhea, or high-output diarrhea, or if the person is immunocompromised, antibiotics may be necessary. NICE recommends the use of clarithromycin, administered at a dose of 250-500 mg twice daily for 5-7 days, starting within 3 days of the onset of illness.

Extrapyramidal side effects are most commonly seen with the piperazine phenothiazines (fluphenazine, prochlorperazine, and trifluoperazine) and butyrophenones (benperidol and haloperidol). Among these, haloperidol is the most frequently implicated antipsychotic drug.

Tardive dyskinesia, which involves rhythmic and involuntary movements of the tongue, face, and jaw, typically develops after long-term treatment or high doses. It is the most severe manifestation of extrapyramidal symptoms, as it may become irreversible even after discontinuing the causative drug, and treatment options are generally ineffective.

Dystonia, characterized by abnormal movements of the face and body, is more commonly observed in children and young adults and tends to occur after only a few doses. Acute dystonia can be managed with intravenous administration of procyclidine (5 mg) or benzatropine (2 mg) as a bolus.

Akathisia refers to an unpleasant sensation of restlessness, while akinesia refers to an inability to initiate movement.

Elderly patients with dementia-related psychosis who are treated with haloperidol have an increased risk of mortality. This is believed to be due to a higher likelihood of experiencing cardiovascular events and infections such as pneumonia.

The risk of infection is highest with femoral central lines.

A central venous catheter (CVC) is a type of catheter that is inserted into a large vein in the body, typically in the neck, chest, or groin. It has several important uses, including CVP monitoring, pulmonary artery pressure monitoring, repeated blood sampling, IV access for large volumes of fluids or drugs, TPN administration, dialysis, pacing, and other procedures such as placement of IVC filters or venous stents.

When inserting a central line, it is ideal to use ultrasound guidance to ensure accurate placement. However, there are certain contraindications to central line insertion, including infection or injury to the planned access site, coagulopathy, thrombosis or stenosis of the intended vein, a combative patient, or raised intracranial pressure for jugular venous lines.

The most common approaches for central line insertion are the internal jugular, subclavian, femoral, and PICC (peripherally inserted central catheter) veins. The internal jugular vein is often chosen due to its proximity to the carotid artery, but variations in anatomy can occur. Ultrasound can be used to identify the vessels and guide catheter placement, with the IJV typically lying superficial and lateral to the carotid artery. Compression and Valsalva maneuvers can help distinguish between arterial and venous structures, and doppler color flow can highlight the direction of flow.

In terms of choosing a side for central line insertion, the right side is usually preferred to avoid the risk of injury to the thoracic duct and potential chylothorax. However, the left side can also be used depending on the clinical situation.

Femoral central lines are another option for central venous access, with the catheter being inserted into the femoral vein in the groin. Local anesthesia is typically used to establish a field block, with lidocaine being the most commonly used agent. Lidocaine works by blocking sodium channels and preventing the propagation of action potentials.

In summary, central venous catheters have various important uses and should ideally be inserted using ultrasound guidance. There are contraindications to their insertion, and different approaches can be used depending on the clinical situation. Local anesthesia is commonly used for central line insertion, with lidocaine being the preferred agent.

The posterior interosseous nerve (PIN) is a motor branch of the radial nerve that is located deep within the body. It emerges above the elbow, between the brachioradialis and brachialis muscles, and then divides into two branches: the superficial radial nerve and the PIN. This division occurs at the lateral epicondyle level. As it travels through the forearm, the PIN passes through the supinator muscle, moving from the front to the back surface. In about 30% of individuals, it also passes through a fibrotendinous structure called the arcade of Frohse, which is located below the supinator muscle. The PIN is responsible for supplying all of the extrinsic wrist extensors, with the exception of the extensor carpi radialis longus muscle.

There are several potential causes of damage to the PIN. Fractures, such as a Monteggia fracture, can lead to injury. Inflammation of the radiocapitellar joint, known as radiocapitellar joint synovitis, can also be a contributing factor. Tumors, such as lipomas, may cause damage as well. Additionally, entrapment of the PIN within the arcade of Frohse can result in a condition known as PIN syndrome.

It is important to note that injury to the PIN can be easily distinguished from injury to the radial nerve in other areas of the arm, such as the spiral groove. This is because there will be no sensory involvement and no wrist drop, as the extensor carpi radialis longus muscle remains unaffected.

The anterior interosseous nerve (AIN) is a branch of the median nerve. It primarily functions as a motor nerve, supplying the flexor pollicis longus muscle, the lateral half of the flexor digitorum profundus muscle, and the pronator quadratus muscle. Damage to the AIN can result in weakness and difficulty moving the index and middle fingers.

Vestibular neuritis is a common complication of vestibular neuronitis, characterized by a following of people experiencing symptoms such as persistent dizziness, unsteadiness, and fear of falling. However, a rare complication called phobic postural vertigo may also occur, where individuals experience these symptoms despite not actually falling.

On the other hand, benign paroxysmal positional vertigo (BPPV) presents with short episodes of vertigo, usually lasting less than 20 seconds, triggered by changes in head position. In contrast, vestibular neuronitis causes constant vertigo, even when at rest, which can be worsened by head movements.

Recovery from vestibular neuronitis is a gradual process that typically takes a few weeks, up to 6 weeks. It is believed that this condition is caused by inflammation of the vestibular nerve following a viral infection. On the other hand, BPPV is thought to occur due to the presence of cellular debris or crystal formation in the semicircular canals.

Further Reading:

Vestibular neuritis, also known as vestibular neuronitis, is a condition characterized by sudden and prolonged vertigo of peripheral origin. It is believed to be caused by inflammation of the vestibular nerve, often following a viral infection. It is important to note that vestibular neuritis and labyrinthitis are not the same condition, as labyrinthitis involves inflammation of the labyrinth. Vestibular neuritis typically affects individuals between the ages of 30 and 60, with a 1:1 ratio of males to females. The annual incidence is approximately 3.5 per 100,000 people, making it one of the most commonly diagnosed causes of vertigo.

Clinical features of vestibular neuritis include nystagmus, which is a rapid, involuntary eye movement, typically in a horizontal or horizontal-torsional direction away from the affected ear. The head impulse test may also be positive. Other symptoms include spontaneous onset of rotational vertigo, which is worsened by changes in head position, as well as nausea, vomiting, and unsteadiness. These severe symptoms usually last for 2-3 days, followed by a gradual recovery over a few weeks. It is important to note that hearing is not affected in vestibular neuritis, and symptoms such as tinnitus and focal neurological deficits are not present.

Differential diagnosis for vestibular neuritis includes benign paroxysmal positional vertigo (BPPV), labyrinthitis, Meniere’s disease, migraine, stroke, and cerebellar lesions. Management of vestibular neuritis involves drug treatment for nausea and vomiting associated with vertigo, typically through short courses of medication such as prochlorperazine or cyclizine. If symptoms are severe and fluids cannot be tolerated, admission and administration of IV fluids may be necessary. General advice should also be given, including avoiding driving while symptomatic, considering the suitability to work based on occupation and duties, and the increased risk of falls. Follow-up is required, and referral is necessary if there are atypical symptoms, symptoms do not improve after a week of treatment, or symptoms persist for more than 6 weeks.

The prognosis for vestibular neuritis is generally good, with the majority of individuals fully recovering within 6 weeks. Recurrence is thought to occur in 2-11% of cases, and approximately 10% of individuals may develop BPPV following an episode of vestibular neuritis. A very rare complication of vestibular neuritis is ph

Prolongation of the QT interval can lead to a dangerous ventricular arrhythmia called torsades de pointes, which can result in sudden cardiac death. There are several commonly used medications that are known to cause QT prolongation.

Low levels of potassium (hypokalaemia) and magnesium (hypomagnesaemia) can increase the risk of QT prolongation. For example, diuretics can interact with QT-prolonging drugs by causing hypokalaemia.

The QT interval varies with heart rate, and formulas are used to correct the QT interval for heart rate. Once corrected, it is referred to as the QTc interval. The QTc interval is typically reported on the ECG printout. A normal QTc interval is less than 440 ms.

If the QTc interval is greater than 440 ms but less than 500 ms, it is considered borderline. Although there may be some variation in the literature, a QTc interval within these values is generally considered borderline prolonged. In such cases, it is important to consider reducing the dose of QT-prolonging drugs or switching to an alternative medication that does not prolong the QT interval.

A prolonged QTc interval exceeding 500 ms is clinically significant and is likely to increase the risk of arrhythmia. Any medications that prolong the QT interval should be reviewed immediately.

Here are some commonly encountered drugs that are known to prolong the QT interval:

Antimicrobials:
– Erythromycin
– Clarithromycin
– Moxifloxacin
– Fluconazole
– Ketoconazole

Antiarrhythmics:
– Dronedarone
– Sotalol
– Quinidine
– Amiodarone
– Flecainide

Antipsychotics:
– Risperidone
– Fluphenazine
– Haloperidol
– Pimozide
– Chlorpromazine
– Quetiapine
– Clozapine

Antidepressants:
– Citalopram/escitalopram
– Amitriptyline
– Clomipramine
– Dosulepin
– Doxepin
– Imipramine
– Lofepramine

Antiemetics:
– Domperidone
– Droperidol
– Ondansetron/Granisetron

Others:
– Methadone
– Protein kinase inhibitors (e.g. sunitinib)

Blood transfusion is a potentially life-saving treatment that can provide great clinical benefits. However, it also carries several risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there has been an increased awareness of these risks and improved reporting systems, transfusion errors and serious adverse reactions still occur and may go unreported.

One specific transfusion reaction is transfusion-associated circulatory overload (TACO), which occurs when a large volume of blood is rapidly infused. It is the second leading cause of transfusion-related deaths, accounting for about 20% of fatalities. TACO is more likely to occur in patients with diminished cardiac reserve or chronic anemia, particularly in the elderly, infants, and severely anemic patients.

The typical clinical features of TACO include acute respiratory distress, tachycardia, hypertension, acute or worsening pulmonary edema on chest X-ray, and evidence of positive fluid balance. The B-type natriuretic peptide (BNP) can be a useful diagnostic tool for TACO, with levels usually elevated to at least 1.5 times the pre-transfusion baseline.

In many cases, simply slowing the transfusion rate, placing the patient in an upright position, and administering diuretics can be sufficient for managing TACO. In more severe cases, the transfusion should be stopped, and non-invasive ventilation may be considered.

The earliest ECG change typically observed in hyperkalemia is the presence of tall tented T-waves.

Further Reading:

Vasoactive drugs can be classified into three categories: inotropes, vasopressors, and unclassified. Inotropes are drugs that alter the force of muscular contraction, particularly in the heart. They primarily stimulate adrenergic receptors and increase myocardial contractility. Commonly used inotropes include adrenaline, dobutamine, dopamine, isoprenaline, and ephedrine.

Vasopressors, on the other hand, increase systemic vascular resistance (SVR) by stimulating alpha-1 receptors, causing vasoconstriction. This leads to an increase in blood pressure. Commonly used vasopressors include norepinephrine, metaraminol, phenylephrine, and vasopressin.

Electrolytes, such as potassium, are essential for proper bodily function. Solutions containing potassium are often given to patients to prevent or treat hypokalemia (low potassium levels). However, administering too much potassium can lead to hyperkalemia (high potassium levels), which can cause dangerous arrhythmias. It is important to monitor potassium levels and administer it at a controlled rate to avoid complications.

Hyperkalemia can be caused by various factors, including excessive potassium intake, decreased renal excretion, endocrine disorders, certain medications, metabolic acidosis, tissue destruction, and massive blood transfusion. It can present with cardiovascular, respiratory, gastrointestinal, and neuromuscular symptoms. ECG changes, such as tall tented T-waves, prolonged PR interval, flat P-waves, widened QRS complex, and sine wave, are also characteristic of hyperkalemia.

In summary, vasoactive drugs can be categorized as inotropes, vasopressors, or unclassified. Inotropes increase myocardial contractility, while vasopressors increase systemic vascular resistance. Electrolytes, particularly potassium, are important for bodily function, but administering too much can lead to hyperkalemia. Monitoring potassium levels and ECG changes is crucial in managing hyperkalemia.

Primary sclerosing cholangitis (PSC) is a condition that affects the bile ducts, causing inflammation and blockage over time. It is more commonly seen in men than women, with a ratio of 3 to 1, and is typically diagnosed around the age of 40. PSC is characterized by recurring episodes of cholangitis and progressive scarring of the bile ducts. If left untreated, it can lead to liver cirrhosis, liver failure, and even hepatocellular carcinoma. PSC is often associated with ulcerative colitis, with more than 80% of PSC patients also having this condition. Other associations include fibrosis in the retroperitoneal and mediastinal areas.

When performing an endoscopic retrograde cholangiopancreatography (ERCP) to diagnose PSC, certain findings are typically observed. These include ulceration of the common bile duct, irregular narrowing with saccular dilatation above the structured ducts (resembling beads-on-a-string or a beaded appearance), and involvement of both the intra- and extrahepatic ducts simultaneously.

Complications that can arise from PSC include liver cirrhosis, portal hypertension, liver failure, and cholangiocarcinoma. Treatment options for PSC include the use of ursodeoxycholic acid to improve symptoms and liver function (although it does not affect the overall prognosis), cholestyramine to alleviate itching, and correction of deficiencies in fat-soluble vitamins. In some cases, endoscopic dilatation of strictures may be necessary.

Liver transplantation is the definitive treatment for PSC. The 10-year survival rate after transplantation is approximately 65%, and the average survival time from the time of diagnosis is around seven years. Patients with PSC often succumb to complications such as secondary biliary cirrhosis, portal hypertension, or cholangitis. Additionally, about 10% of PSC patients will develop cholangiocarcinoma.

According to the 2011 recommendations from the World Health Organization (WHO), HbA1c can now be used as a diagnostic test for diabetes. However, this is only applicable if stringent quality assurance tests are in place and the assays are standardized to criteria aligned with international reference values. Additionally, accurate measurement of HbA1c is only possible if there are no conditions present that could hinder its accuracy.

To diagnose diabetes using HbA1c, a value of 48 mmol/mol (6.5%) is recommended as the cut-off point. It’s important to note that a value lower than 48 mmol/mol (6.5%) does not exclude the possibility of diabetes, as glucose tests are still necessary for a definitive diagnosis.

When using glucose tests, the following criteria are considered diagnostic for diabetes mellitus:
– A random venous plasma glucose concentration greater than 11.1 mmol/l
– A fasting plasma glucose concentration greater than 7.0 mmol/l
– A two-hour plasma glucose concentration greater than 11.1 mmol/l, two hours after consuming 75g of anhydrous glucose in an oral glucose tolerance test (OGTT)

However, there are certain circumstances where HbA1c is not appropriate for diagnosing diabetes mellitus. These include:
– ALL children and young people
– Patients of any age suspected of having Type 1 diabetes
– Patients with symptoms of diabetes for less than two months
– Patients at high risk of diabetes who are acutely ill, such as those requiring hospital admission
– Patients taking medication that may cause a rapid rise in glucose levels, such as steroids or antipsychotics
– Patients with acute pancreatic damage, including those who have undergone pancreatic surgery
– Pregnant individuals
– Presence of genetic, hematologic, and illness-related factors that can influence HbA1c and its measurement.

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.

A tension pneumothorax occurs when there is an air leak from the lung or chest wall that acts like a one-way valve. This causes air to build up in the pleural space without any way to escape. As a result, the pressure in the pleural space increases and pushes the mediastinum into the opposite side of the chest. If left untreated, this can lead to cardiovascular instability and even cardiac arrest.

The clinical features that are typically seen in tension pneumothorax include respiratory distress and cardiovascular instability. Tracheal deviation away from the side of injury, unilateral absence of breath sounds on the affected side, and a hyper-resonant percussion note are also characteristic. Other signs may include distended neck veins and cyanosis, although cyanosis is usually a late sign.

Both tension pneumothorax and massive haemothorax can cause decreased breath sounds on auscultation. However, they can be differentiated by percussion. Hyper-resonance suggests tension pneumothorax, while dullness indicates a massive haemothorax.

It is important to note that tension pneumothorax is a clinical diagnosis and treatment should not be delayed for radiological confirmation. Immediate decompression through needle thoracocentesis is the recommended treatment. Traditionally, a large-bore needle or cannula is inserted into the 2nd intercostal space in the midclavicular line of the affected side. However, studies have shown that using the 4th or 5th intercostal space in the midaxillary line has better success in reaching the thoracic cavity in adult patients. ATLS now recommends this location for needle decompression in adults. The location for children remains the same, and the 2nd intercostal space in the midclavicular line should still be used. It is important to remember that needle thoracocentesis is a temporary measure and definitive treatment involves the insertion of a chest drain.

Flumazenil is a specific antagonist for benzodiazepines that can be beneficial in certain situations. It acts quickly, taking less than 1 minute to take effect, but its effects are short-lived and only last for less than 1 hour. The recommended dosage is 200 μg every 1-2 minutes, with a maximum dose of 3mg per hour.

It is important to avoid using Flumazenil if the patient is dependent on benzodiazepines or is taking tricyclic antidepressants. This is because it can trigger a withdrawal syndrome in these individuals, potentially leading to seizures or cardiac arrest.

Adrenaline is recommended to be administered after the third shock in a shockable cardiac arrest (Vf/pVT) once chest compressions have been resumed. The recommended dose is 1 mg, which can be administered as either 10 mL of a 1:10,000 solution or 1 mL of a 1:1000 solution.

Subsequently, adrenaline should be given every 3-5 minutes, alternating with chest compressions. It is important to administer adrenaline without interrupting chest compressions to ensure continuous circulation and maximize the chances of successful resuscitation.

When performing CPR on patients with severe hypothermia, it is recommended to limit defibrillation attempts to three. Hypothermia is characterized by a core temperature below 35ºC, with mild hypothermia ranging from 32-35ºC, moderate hypothermia from 30-32ºC, and severe hypothermia below 30ºC. This condition often occurs after drowning. If the individual’s core body temperature is below 30°C, it is advised to administer a maximum of three shocks using the highest output of the defibrillator.

Further Reading:

Cardiopulmonary arrest is a serious event with low survival rates. In non-traumatic cardiac arrest, only about 20% of patients who arrest as an in-patient survive to hospital discharge, while the survival rate for out-of-hospital cardiac arrest is approximately 8%. The Resus Council BLS/AED Algorithm for 2015 recommends chest compressions at a rate of 100-120 per minute with a compression depth of 5-6 cm. The ratio of chest compressions to rescue breaths is 30:2.

After a cardiac arrest, the goal of patient care is to minimize the impact of post cardiac arrest syndrome, which includes brain injury, myocardial dysfunction, the ischaemic/reperfusion response, and the underlying pathology that caused the arrest. The ABCDE approach is used for clinical assessment and general management. Intubation may be necessary if the airway cannot be maintained by simple measures or if it is immediately threatened. Controlled ventilation is aimed at maintaining oxygen saturation levels between 94-98% and normocarbia. Fluid status may be difficult to judge, but a target mean arterial pressure (MAP) between 65 and 100 mmHg is recommended. Inotropes may be administered to maintain blood pressure. Sedation should be adequate to gain control of ventilation, and short-acting sedating agents like propofol are preferred. Blood glucose levels should be maintained below 8 mmol/l. Pyrexia should be avoided, and there is some evidence for controlled mild hypothermia but no consensus on this.

Post ROSC investigations may include a chest X-ray, ECG monitoring, serial potassium and lactate measurements, and other imaging modalities like ultrasonography, echocardiography, CTPA, and CT head, depending on availability and skills in the local department. Treatment should be directed towards the underlying cause, and PCI or thrombolysis may be considered for acute coronary syndrome or suspected pulmonary embolism, respectively.

Patients who are comatose after ROSC without significant pre-arrest comorbidities should be transferred to the ICU for supportive care. Neurological outcome at 72 hours is the best prognostic indicator of outcome.