Acute limb ischaemia refers to a sudden reduction in blood flow to a limb, which puts the limb at risk of tissue death. This condition is most commonly caused by either a sudden blockage of a previously partially blocked artery by a blood clot or by an embolus that travels from another part of the body. Acute limb ischaemia is considered a medical emergency, and if not promptly treated with surgery to restore blood flow, it can lead to extensive tissue damage within six hours.

The classic signs of acute limb ischaemia are often described using the 6 Ps:
– Pain that is constant and persistent
– Absence of pulses in the ankle
– Pallor, cyanosis, or mottling of the skin
– Loss of power or paralysis in the affected limb
– Paraesthesia or reduced sensation, leading to numbness
– Feeling cold in the affected limb

It is important to be able to distinguish between ischaemia caused by a blood clot and ischaemia caused by an embolus. The following highlights the main differences:
Embolus Thrombus
– Onset is sudden, occurring within seconds to minutes – Onset is gradual, taking hours to days
– Ischaemia is usually severe due to the lack of collateral circulation – Ischaemia is less severe due to the presence of collateral circulation
– There is typically no history of claudication, and pulses may still be present in the other leg – There is often a history of claudication, and pulses may also be absent in the other leg
– Skin changes, such as marbling, may be visible in the feet. This can appear as a fine reticular blanching or mottling in the early stages, progressing to coarse, fixed mottling
– Skin changes are usually absent in cases of thrombus-induced ischaemia.

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

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

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

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

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

During pre-oxygenation, inspired Oxygen primarily works by removing Nitrogen and increasing the presence of Oxygen. Additionally, it helps to optimize the levels of oxygen in the alveolar, arterial, tissue, and venous areas.

Further Reading:

Rapid sequence induction (RSI) is a method used to place an endotracheal tube (ETT) in the trachea while minimizing the risk of aspiration. It involves inducing loss of consciousness while applying cricoid pressure, followed by intubation without face mask ventilation. The steps of RSI can be remembered using the 7 P’s: preparation, pre-oxygenation, pre-treatment, paralysis and induction, protection and positioning, placement with proof, and post-intubation management.

Preparation involves preparing the patient, equipment, team, and anticipating any difficulties that may arise during the procedure. Pre-oxygenation is important to ensure the patient has an adequate oxygen reserve and prolongs the time before desaturation. This is typically done by breathing 100% oxygen for 3 minutes. Pre-treatment involves administering drugs to counter expected side effects of the procedure and anesthesia agents used.

Paralysis and induction involve administering a rapid-acting induction agent followed by a neuromuscular blocking agent. Commonly used induction agents include propofol, ketamine, thiopentone, and etomidate. The neuromuscular blocking agents can be depolarizing (such as suxamethonium) or non-depolarizing (such as rocuronium). Depolarizing agents bind to acetylcholine receptors and generate an action potential, while non-depolarizing agents act as competitive antagonists.

Protection and positioning involve applying cricoid pressure to prevent regurgitation of gastric contents and positioning the patient’s neck appropriately. Tube placement is confirmed by visualizing the tube passing between the vocal cords, auscultation of the chest and stomach, end-tidal CO2 measurement, and visualizing misting of the tube. Post-intubation management includes standard care such as monitoring ECG, SpO2, NIBP, capnography, and maintaining sedation and neuromuscular blockade.

Overall, RSI is a technique used to quickly and safely secure the airway in patients who may be at risk of aspiration. It involves a series of steps to ensure proper preparation, oxygenation, drug administration, and tube placement. Monitoring and post-intubation care are also important aspects of RSI.

Women have three options when requesting emergency contraception. The first option is Levonelle 1.5 mg, which contains levonorgestrel and can be used up to 72 hours after unprotected sexual intercourse (UPSI). If vomiting occurs within 2 hours of taking the tablet, another one should be given. Levonelle mainly works by preventing ovulation.

The second option is ulipristal acetate, the newest treatment available. It can be used up to 120 hours after UPSI. If vomiting occurs within 3 hours of ingestion, another tablet should be given. Ulipristal acetate also works by inhibiting ovulation. However, it should be avoided in patients taking enzyme-inducing drugs, those with severe hepatic impairment, or those with severe asthma requiring oral steroids.

The third option is the copper IUD, which can be fitted up to 5 days after UPSI or ovulation, whichever is longer. The failure rate of the copper IUD is less than 1 in 1000, making it 10-20 times more effective than oral emergency contraceptive options. It is important to note that Levonelle and ulipristal may be less effective in women with higher BMIs.

Acute pancreatitis is a common and serious cause of acute abdominal pain. It occurs when the pancreas becomes inflamed, leading to the release of enzymes that cause self-digestion of the organ.

The most common causes of acute pancreatitis are gallstones and alcohol consumption. Many cases are also of unknown origin. To remember the various causes, the mnemonic ‘I GET SMASHED’ can be helpful:

– I: Idiopathic
– G: Gallstones
– E: Ethanol
– T: Trauma
– S: Steroids
– M: Mumps
– A: Autoimmune
– S: Scorpion stings
– H: Hyperlipidemia/hypercalcemia
– E: ERCP
– D: Drugs

The clinical features of acute pancreatitis include severe epigastric pain, nausea and vomiting, referral of pain to specific dermatomes (or shoulder tip via the phrenic nerve), fever/sepsis, epigastric tenderness, jaundice, and signs such as Gray-Turner sign (ecchymosis of the flank) and Cullen sign (ecchymosis of the peri-umbilical area).

The stimulation of the thoracic splanchnic nerves is responsible for the referred pain to the T6-10 dermatomes that is sometimes observed in pancreatitis and other pancreatic disorders.

When investigating acute pancreatitis in the emergency department, it is important to perform blood glucose testing, a full blood count (which often shows an elevated white cell count), urea and electrolyte testing, calcium testing, liver function tests, coagulation screening, serum amylase testing (which should be more than 5 times the normal limit), an ECG, arterial blood gas analysis, and an abdominal X-ray.

Treatment for acute pancreatitis involves providing the patient with oxygen, adequate pain relief (including antiemetics), and fluid resuscitation. A nasogastric tube and urinary catheter should be inserted, and fluid balance should be carefully monitored. Most patients require management in a high dependency unit (HDU) or intensive care unit (ICU) setting.

Acute pancreatitis has a significant mortality rate, and complications are common. Early complications may include severe sepsis and circulatory shock, acute renal failure, disseminated intravascular coagulation, hypocalcemia, acute respiratory distress syndrome and pancreatic encephalopathy.

The first step in decontaminating radioactive material from an individual is to remove their clothing carefully, without shaking it too much to avoid spreading radioactive dust. The clothing should then be placed in a plastic bag or sealable container. Next, the person should be washed down with warm water from a clean source and scrubbed with detergent using a rinse-wipe-rinse method.

Further Reading:

Radiation exposure refers to the emission or transmission of energy in the form of waves or particles through space or a material medium. There are two types of radiation: ionizing and non-ionizing. Non-ionizing radiation, such as radio waves and visible light, has enough energy to move atoms within a molecule but not enough to remove electrons from atoms. Ionizing radiation, on the other hand, has enough energy to ionize atoms or molecules by detaching electrons from them.

There are different types of ionizing radiation, including alpha particles, beta particles, gamma rays, and X-rays. Alpha particles are positively charged and consist of 2 protons and 2 neutrons from the atom’s nucleus. They are emitted from the decay of heavy radioactive elements and do not travel far from the source atom. Beta particles are small, fast-moving particles with a negative electrical charge that are emitted from an atom’s nucleus during radioactive decay. They are more penetrating than alpha particles but less damaging to living tissue. Gamma rays and X-rays are weightless packets of energy called photons. Gamma rays are often emitted along with alpha or beta particles during radioactive decay and can easily penetrate barriers. X-rays, on the other hand, are generally lower in energy and less penetrating than gamma rays.

Exposure to ionizing radiation can damage tissue cells by dislodging orbital electrons, leading to the generation of highly reactive ion pairs. This can result in DNA damage and an increased risk of future malignant change. The extent of cell damage depends on factors such as the type of radiation, time duration of exposure, distance from the source, and extent of shielding.

The absorbed dose of radiation is directly proportional to time, so it is important to minimize the amount of time spent in the vicinity of a radioactive source. A lethal dose of radiation without medical management is 4.5 sieverts (Sv) to kill 50% of the population at 60 days. With medical management, the lethal dose is 5-6 Sv. The immediate effects of ionizing radiation can range from radiation burns to radiation sickness, which is divided into three main syndromes: hematopoietic, gastrointestinal, and neurovascular. Long-term effects can include hematopoietic cancers and solid tumor formation.

In terms of management, support is mainly supportive and includes IV fluids, antiemetics, analgesia, nutritional support, antibiotics, blood component substitution, and reduction of brain edema.

Moderate hypothermia is indicated by core temperatures ranging from 28-32ºC.

Further Reading:

Hypothermia is defined as a core temperature below 35ºC and can be graded as mild, moderate, severe, or profound based on the core temperature. When the core temperature drops, the basal metabolic rate decreases and cell signaling between neurons decreases, leading to reduced tissue perfusion. This can result in depressed myocardial contractility, vasoconstriction, ventilation-perfusion mismatch, and increased blood viscosity. Symptoms of hypothermia progress as the core temperature drops, starting with compensatory increases in heart rate and shivering, and eventually leading to bradyarrhythmias, prolonged PR, QRS, and QT intervals, and cardiac arrest.

In the management of hypothermic cardiac arrest, ALS should be initiated with some modifications. The pulse check during CPR should be prolonged to 1 minute due to difficulty in obtaining a pulse. Rewarming the patient is important, and mechanical ventilation may be necessary due to stiffness of the chest wall. Drug metabolism is slowed in hypothermic patients, so dosing of drugs should be adjusted or withheld. Electrolyte disturbances are common in hypothermic patients and should be corrected.

Frostbite refers to a freezing injury to human tissue and occurs when tissue temperature drops below 0ºC. It can be classified as superficial or deep, with superficial frostbite affecting the skin and subcutaneous tissues, and deep frostbite affecting bones, joints, and tendons. Frostbite can be classified from 1st to 4th degree based on the severity of the injury. Risk factors for frostbite include environmental factors such as cold weather exposure and medical factors such as peripheral vascular disease and diabetes.

Signs and symptoms of frostbite include skin changes, cold sensation or firmness to the affected area, stinging, burning, or numbness, clumsiness of the affected extremity, and excessive sweating, hyperemia, and tissue gangrene. Frostbite is diagnosed clinically and imaging may be used in some cases to assess perfusion or visualize occluded vessels. Management involves moving the patient to a warm environment, removing wet clothing, and rapidly rewarming the affected tissue. Analgesia should be given as reperfusion is painful, and blisters should be de-roofed and aloe vera applied. Compartment syndrome is a risk and should be monitored for. Severe cases may require surgical debridement of amputation.

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)

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

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

The table below summarizes the most common causes of AKI:

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

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

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

The Civil Contingencies Act 2004 establishes a framework for civil protection in the United Kingdom. This legislation categorizes local responders to major incidents into two groups, each with their own set of responsibilities.

Category 1 responders consist of organizations that play a central role in responding to most emergencies, such as the emergency services, local authorities, and NHS bodies. These Category 1 responders are obligated to fulfill a comprehensive range of civil protection duties. These duties include assessing the likelihood of emergencies occurring and using this information to inform contingency planning. They must also develop emergency plans, establish business continuity management arrangements, and ensure that information regarding civil protection matters is readily available to the public. Additionally, Category 1 responders are responsible for maintaining systems to warn, inform, and advise the public in the event of an emergency. They are expected to share information with other local responders to enhance coordination and efficiency. Furthermore, local authorities within this category are required to provide guidance and support to businesses and voluntary organizations regarding business continuity management.

On the other hand, Category 2 organizations, such as the Health and Safety Executive, transport companies, and utility companies, are considered co-operating bodies. While they may not be directly involved in the core planning work, they play a crucial role in incidents that impact their respective sectors. Category 2 responders have a more limited set of duties, primarily focused on cooperating and sharing relevant information with both Category 1 and Category 2 responders.

For more information on this topic, please refer to the Civil Contingencies Act 2004.

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.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur. One common adverse reaction is febrile transfusion reactions, which present as an unexpected rise in temperature during or after transfusion. This can be caused by cytokine accumulation or recipient antibodies reacting to donor antigens. Treatment for febrile transfusion reactions is supportive, and other potential causes should be ruled out.

Another serious complication is acute haemolytic reaction, which is often caused by ABO incompatibility due to administration errors. This reaction requires the transfusion to be stopped and IV fluids to be administered. Delayed haemolytic reactions can occur several days after a transfusion and may require monitoring and treatment for anaemia and renal function. Allergic reactions, TRALI (Transfusion Related Acute Lung Injury), TACO (Transfusion Associated Circulatory Overload), and GVHD (Graft-vs-Host Disease) are other potential complications that require specific management approaches.

In summary, blood transfusion carries risks and potential complications, but efforts have been made to improve safety procedures. It is important to be aware of these complications and to promptly address any adverse reactions that may occur during or after a transfusion.

Scleritis is a serious condition characterized by inflammation of the sclera, the white outer layer of the eye. It often affects both eyes, with bilateral involvement seen in about half of the cases. While the cause of scleritis can be unknown (idiopathic), it is associated with systemic inflammatory diseases like rheumatoid arthritis in approximately one-third of patients. In fact, scleritis can sometimes be the initial manifestation of these inflammatory conditions.

The clinical features of scleritis include moderate to severe pain, which can be felt in the brow or jaw. The pain worsens with eye movement and may disrupt sleep. The onset of symptoms is typically gradual. Other common symptoms include sensitivity to light (photophobia), excessive tearing (epiphora), and redness of both the superficial and deep episcleral vessels. The affected eye may also be tender to touch, and there may be a decrease in visual acuity. Some individuals may have a history of previous episodes of scleritis.

In summary, scleritis is a serious inflammatory disease of the sclera that can be associated with systemic inflammatory conditions. It presents with significant pain, often referred to the brow or jaw, and worsened by eye movement. Other symptoms include photophobia, excessive tearing, and redness of the episcleral vessels. It is important to recognize scleritis as it can be the first sign of underlying inflammatory diseases.

In an elderly patient with a history of gradual decline accompanied by high blood sugar levels, excessive thirst, and recent infection, the most likely diagnosis is hyperosmolar hyperglycemic state (HHS). This condition can be life-threatening, with a mortality rate of approximately 50%. Common symptoms include dehydration, elevated blood sugar levels, altered mental status, and electrolyte imbalances. About half of the patients with HHS also experience hypernatremia.

To calculate the serum osmolality, the formula is 2(K+ + Na+) + urea + glucose. In this case, the serum osmolality is 364 mmol/l, indicating a high level. It is important to discontinue the use of metformin in this patient due to the risk of metformin-associated lactic acidosis (MALA). Additionally, an intravenous infusion of insulin should be initiated.

The treatment goals for HHS are to address the underlying cause and gradually and safely:
– Normalize the osmolality
– Replace fluid and electrolyte losses
– Normalize blood glucose levels

If significant ketonaemia is present (3β-hydroxybutyrate is more than 1 mmol/L), it indicates a relative lack of insulin, and insulin should be administered immediately. However, if significant ketonaemia is not present, insulin should not be started.

Patients with HHS are at a high risk of thromboembolism, and it is recommended to routinely administer low molecular weight heparin. In cases where the serum osmolality exceeds 350 mmol/l, full heparinization should be considered.

Croup, also known as laryngotracheobronchitis, is a respiratory infection that primarily affects infants and toddlers. It is characterized by a barking cough and can cause stridor (a high-pitched sound during breathing) and respiratory distress due to swelling of the larynx and excessive secretions. The majority of cases are caused by parainfluenza viruses 1 and 3. Croup is most common in children between 6 months and 3 years of age and tends to occur more frequently in the autumn.

The clinical features of croup include a barking cough that is worse at night, preceded by symptoms of an upper respiratory tract infection such as cough, runny nose, and congestion. Stridor, respiratory distress, and fever may also be present. The severity of croup can be graded using the NICE system, which categorizes it as mild, moderate, severe, or impending respiratory failure based on the presence of symptoms such as cough, stridor, sternal/intercostal recession, agitation, lethargy, and decreased level of consciousness. The Westley croup score is another commonly used tool to assess the severity of croup based on the presence of stridor, retractions, air entry, oxygen saturation levels, and level of consciousness.

In cases of severe croup with significant airway obstruction and impending respiratory failure, symptoms may include a minimal barking cough, harder-to-hear stridor, chest wall recession, fatigue, pallor or cyanosis, decreased level of consciousness, and tachycardia. A respiratory rate over 70 breaths per minute is also indicative of severe respiratory distress.

Children with moderate or severe croup, as well as those with certain risk factors such as chronic lung disease, congenital heart disease, neuromuscular disorders, immunodeficiency, age under 3 months, inadequate fluid intake, concerns about care at home, or high fever or a toxic appearance, should be admitted to the hospital. The mainstay of treatment for croup is corticosteroids, which are typically given orally. If the child is too unwell to take oral medication, inhaled budesonide or intramuscular dexamethasone may be used as alternatives. Severe cases may require high-flow oxygen and nebulized adrenaline.

When considering the differential diagnosis for acute stridor and breathing difficulty, non-infective causes such as inhaled foreign bodies

This patient has been diagnosed with primary biliary cirrhosis (PBC). PBC is a liver disease caused by an autoimmune response, leading to the progressive destruction of the small bile ducts in the liver. The damage primarily affects the intralobular ducts. As a result, the patient experiences cholestatic jaundice, followed by liver fibrosis and cirrhosis. PBC is more common in females, with 90% of patients being women. It typically occurs between the ages of 30 and 65. Liver function tests show elevated levels of alkaline phosphatase (ALP), often before any symptoms appear. Antimitochondrial antibodies are positive in 95% of cases. Around 50% of patients have smooth muscle antibodies (SMA), and approximately 20% have antinuclear antibodies (ANA). IgM levels are raised in over 80% of cases.

Autoimmune hepatitis is liver inflammation caused by a decrease in regulatory T-cells (Treg cells), leading to the production of autoantibodies against hepatocyte surface antigens. It mainly affects women (70%) between the ages of 15 and 40. The condition causes chronic, progressive hepatitis, which eventually progresses to cirrhosis. Patients typically present with non-specific symptoms of malaise, although in some cases, the disease may be more advanced, resulting in jaundice and severe illness. In later stages, liver function tests show significantly elevated levels of transaminases (ALT and AST), often exceeding ten times the normal range. Alkaline phosphatase (ALP) levels are usually normal or slightly elevated. Antinuclear antibodies (ANA) are positive in approximately 80% of cases, while smooth muscle antibodies (SMA) are positive in around 70% of cases. Antimitochondrial antibodies are typically low or absent.

Primary sclerosing cholangitis (PSC) is a condition that causes progressive inflammation and obstruction of the bile ducts. It is characterized by recurrent episodes of cholangitis and the gradual scarring of the bile ducts. PSC can eventually lead to liver cirrhosis, liver failure, and hepatocellular carcinoma. There is a known association between PSC and ulcerative colitis, with over 80% of PSC patients also having ulcerative colitis.

Hepatic damage caused by hydroxychloroquine is extremely rare.

Patients with active cancer and a confirmed deep-vein thrombosis (DVT) should be considered for treatment with a direct oral anticoagulant (DOAC) such as apixaban. If a DOAC is not suitable for the patient, alternative options should be offered. One option is the use of low-molecular-weight heparin (LMWH) alone. Another option is the combination of LMWH and a vitamin K antagonist (VKA) like warfarin, which should be given for at least 5 days or until the international normalized ratio (INR) reaches at least 2.0 on 2 consecutive readings. After achieving the desired INR, the patient can continue with a VKA alone. It is important to note that anticoagulation treatment should be offered for a period of 3-6 months. to the NICE guidance on the diagnosis and management of venous thromboembolism.

In patients with COPD and type 2 respiratory failure, the desired range for oxygen saturation while receiving BiPAP is typically 88-92%.

Maintaining oxygen saturation within this range is crucial for individuals with COPD as it helps strike a balance between providing enough oxygen to meet the body’s needs and avoiding the risk of oxygen toxicity. Oxygen saturation levels below 88% may indicate inadequate oxygenation, while levels above 92% may lead to oxygen toxicity and other complications.

Further Reading:

Mechanical ventilation is the use of artificial means to assist or replace spontaneous breathing. It can be invasive, involving instrumentation inside the trachea, or non-invasive, where there is no instrumentation of the trachea. Non-invasive mechanical ventilation (NIV) in the emergency department typically refers to the use of CPAP or BiPAP.

CPAP, or continuous positive airways pressure, involves delivering air or oxygen through a tight-fitting face mask to maintain a continuous positive pressure throughout the patient’s respiratory cycle. This helps maintain small airway patency, improves oxygenation, decreases airway resistance, and reduces the work of breathing. CPAP is mainly used for acute cardiogenic pulmonary edema.

BiPAP, or biphasic positive airways pressure, also provides positive airway pressure but with variations during the respiratory cycle. The pressure is higher during inspiration than expiration, generating a tidal volume that assists ventilation. BiPAP is mainly indicated for type 2 respiratory failure in patients with COPD who are already on maximal medical therapy.

The pressure settings for CPAP typically start at 5 cmH2O and can be increased to a maximum of 15 cmH2O. For BiPAP, the starting pressure for expiratory pressure (EPAP) or positive end-expiratory pressure (PEEP) is 3-5 cmH2O, while the starting pressure for inspiratory pressure (IPAP) is 10-15 cmH2O. These pressures can be titrated up if there is persisting hypoxia or acidosis.

In terms of lung protective ventilation, low tidal volumes of 5-8 ml/kg are used to prevent atelectasis and reduce the risk of lung injury. Inspiratory pressures (plateau pressure) should be kept below 30 cm of water, and permissible hypercapnia may be allowed. However, there are contraindications to lung protective ventilation, such as unacceptable levels of hypercapnia, acidosis, and hypoxemia.

Overall, mechanical ventilation, whether invasive or non-invasive, is used in various respiratory and non-respiratory conditions to support or replace spontaneous breathing and improve oxygenation and ventilation.

Gout and pseudogout are both characterized by the presence of crystal deposits in the joints that are affected. Gout occurs when urate crystals are deposited, while pseudogout occurs when calcium pyrophosphate crystals are deposited. Under a microscope, these crystals can be distinguished by their appearance. Urate crystals are needle-shaped and negatively birefringent, while calcium pyrophosphate crystals are brick-shaped and positively birefringent.

Gout can affect any joint in the body, but it most commonly manifests in the hallux metatarsophalangeal joint, which is the joint at the base of the big toe. This joint is affected in approximately 50% of gout cases. On the other hand, pseudogout primarily affects the larger joints, such as the knee.

According to the ALS algorithm, the main drugs used during CPR are oxygen, adrenaline, and amiodarone. Adrenaline is administered every 3-5 minutes as per the 2021 UK ALS algorithm. Amiodarone is given after 3 shocks.

Further Reading:

In the event of an adult experiencing cardiorespiratory arrest, it is crucial for doctors to be familiar with the Advanced Life Support (ALS) algorithm. They should also be knowledgeable about the proper technique for chest compressions, the appropriate rhythms for defibrillation, the reversible causes of arrest, and the drugs used in advanced life support.

During chest compressions, the rate should be between 100-120 compressions per minute, with a depth of compression of 5-6 cm. The ratio of chest compressions to rescue breaths should be 30:2. It is important to change the person giving compressions regularly to prevent fatigue.

There are two shockable ECG rhythms that doctors should be aware of: ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT). These rhythms require defibrillation.

There are four reversible causes of cardiorespiratory arrest, known as the 4 H’s and 4 T’s. The 4 H’s include hypoxia, hypovolemia, hypo or hyperkalemia or metabolic abnormalities, and hypothermia. The 4 T’s include thrombosis (coronary or pulmonary), tension pneumothorax, tamponade, and toxins. Identifying and treating these reversible causes is crucial for successful resuscitation.

When it comes to resus drugs, they are considered of secondary importance during CPR due to the lack of high-quality evidence for their efficacy. However, adrenaline (epinephrine) and amiodarone are the two drugs included in the ALS algorithm. Doctors should be familiar with the dosing, route, and timing of administration for both drugs.

Adrenaline should be administered intravenously at a concentration of 1 in 10,000 (100 micrograms/mL). It should be repeated every 3-5 minutes. Amiodarone is initially given at a dose of 300 mg, either from a pre-filled syringe or diluted in 20 mL of Glucose 5%. If required, an additional dose of 150 mg can be given by intravenous injection. This is followed by an intravenous infusion of 900 mg over 24 hours. The first dose of amiodarone is given after 3 shocks.

Cardiac tamponade is characterized by several classical signs, including distended neck veins, muffled heart sounds, and hypotension. When neck veins are distended, it suggests that the right ventricle is not filling properly. In cases of trauma, this is often caused by the compression of air (tension pneumothorax) or fluid (blood in the pericardial space). One important distinguishing feature is the deviation of the trachea.

Further Reading:

Cardiac tamponade, also known as pericardial tamponade, occurs when fluid accumulates in the pericardial sac and compresses the heart, leading to compromised blood flow. Classic clinical signs of cardiac tamponade include distended neck veins, hypotension, muffled heart sounds, and pulseless electrical activity (PEA). Diagnosis is typically done through a FAST scan or an echocardiogram.

Management of cardiac tamponade involves assessing for other injuries, administering IV fluids to reduce preload, performing pericardiocentesis (inserting a needle into the pericardial cavity to drain fluid), and potentially performing a thoracotomy. It is important to note that untreated expanding cardiac tamponade can progress to PEA cardiac arrest.

Pericardiocentesis can be done using the subxiphoid approach or by inserting a needle between the 5th and 6th intercostal spaces at the left sternal border. Echo guidance is the gold standard for pericardiocentesis, but it may not be available in a resuscitation situation. Complications of pericardiocentesis include ST elevation or ventricular ectopics, myocardial perforation, bleeding, pneumothorax, arrhythmia, acute pulmonary edema, and acute ventricular dilatation.

It is important to note that pericardiocentesis is typically used as a temporary measure until a thoracotomy can be performed. Recent articles published on the RCEM learning platform suggest that pericardiocentesis has a low success rate and may delay thoracotomy, so it is advised against unless there are no other options available.

This patient’s medical history suggests a diagnosis of acute coronary syndrome. It is important to provide pain relief as soon as possible. This can be achieved by administering GTN (sublingual or buccal), but if there is suspicion of an acute myocardial infarction (MI), intravenous opioids such as morphine should be offered.

Aspirin should be given to all patients with unstable angina or NSTEMI as soon as possible and should be continued indefinitely, unless there are contraindications such as a high risk of bleeding or aspirin hypersensitivity. A single loading dose of 300 mg should be given immediately after presentation.

For patients without a high risk of bleeding and no planned coronary angiography within 24 hours of admission, fondaparinux should be administered. However, if coronary angiography is planned within 24 hours, unfractionated heparin can be offered as an alternative to fondaparinux. For patients with significant renal impairment (creatinine above 265 micromoles per litre), unfractionated heparin should be considered, with dose adjustment based on clotting function monitoring.

Routine administration of oxygen is no longer recommended, but oxygen saturation should be monitored using pulse oximetry as soon as possible, preferably before hospital admission. Supplemental oxygen should only be given to individuals with an oxygen saturation (SpO2) below 94% who are not at risk of hypercapnic respiratory failure, aiming for an SpO2 of 94-98%. For individuals with chronic obstructive pulmonary disease at risk of hypercapnic respiratory failure, a target SpO2 of 88-92% should be achieved until blood gas analysis is available.

Bivalirudin, a specific and reversible direct thrombin inhibitor (DTI), is recommended by NICE as a potential treatment for adults with STEMI undergoing percutaneous coronary intervention.

For more information, refer to the NICE guidelines on the assessment and diagnosis of chest pain of recent onset.

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, immune dilution, and transfusion errors. While there have been improvements in safety procedures and efforts to minimize the use of transfusion, errors and serious adverse reactions still occur and often go unreported.

One rare complication of blood transfusion is transfusion-associated graft-vs-host disease (TA-GVHD). This condition typically presents with fever, rash, and diarrhea 1-4 weeks after the transfusion. Laboratory findings may show pancytopenia and abnormalities in liver function. Unlike GVHD after marrow transplantation, TA-GVHD leads to severe marrow aplasia with a mortality rate exceeding 90%. Unfortunately, there are currently no effective treatments available for this condition, and survival is rare, with death usually occurring within 1-3 weeks of the first symptoms.

During a blood transfusion, viable T lymphocytes from the donor are transfused into the recipient’s body. In TA-GVHD, these lymphocytes engraft and react against the recipient’s tissues. However, the recipient is unable to reject the donor lymphocytes due to factors such as immunodeficiency, severe immunosuppression, or shared HLA antigens. Supportive management is the only option for TA-GVHD.

The following summarizes the main complications and reactions that can occur during a blood transfusion:

Complication Features Management
Febrile transfusion reaction
– Presents with a 1-degree rise in temperature from baseline, along with chills and malaise.
– Most common reaction, occurring in 1 out of 8 transfusions.
– Usually caused by cytokines from leukocytes in transfused red cell or platelet components.
– Supportive management, with the use of paracetamol for symptom relief.

Acute haemolytic reaction
– Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine.
– Often accompanied by a feeling of ‘impending doom’.
– Most serious type of reaction, often due to ABO incompatibility caused by administration errors.
– Immediate action required: stop the transfusion, administer IV fluids, and consider diuretics if necessary.

Delayed haemolytic reaction
– Typically occurs 4-8 days after a blood transfusion.
– Symptoms include fever, anemia and/or hyperbilirubinemia

When assessing a patient with epistaxis (nosebleed), it is important to start with a standard ABC assessment, focusing on the airway and hemodynamic status. Even if the bleeding appears to have stopped, it is crucial to evaluate the patient’s condition. If active bleeding is still present and there are signs of hemodynamic compromise, immediate resuscitative and first aid measures should be initiated.

Epistaxis should be treated as a circulatory emergency, especially in elderly patients, those with clotting disorders or bleeding tendencies, and individuals taking anticoagulants. In these cases, it is necessary to establish intravenous access using at least an 18-gauge (green) cannula. Blood samples, including a full blood count, urea and electrolytes, clotting profile, and group and save (depending on the amount of blood loss), should be sent for analysis. Patients should be assigned to a majors or closely observed area, as dislodgement of a blood clot can lead to severe bleeding.

First aid measures to control bleeding include the following steps:
1. The patient should be seated upright with their body tilted forward and their mouth open. Lying down should be avoided, unless the patient feels faint or there is evidence of hemodynamic compromise. Leaning forward helps reduce the flow of blood into the nasopharynx.
2. The patient should be encouraged to spit out any blood that enters the throat and advised not to swallow it.
3. Firmly pinch the soft, cartilaginous part of the nose, compressing the nostrils for 10-15 minutes. Pressure should not be released, and the patient should breathe through their mouth.
4. If the patient is unable to comply, an alternative technique is to ask a relative, staff member, or use an external pressure device like a swimmer’s nose clip.
5. It is important to dispel the misconception that compressing the bones will help stop the bleeding. Applying ice to the neck or forehead does not influence nasal blood flow. However, sucking on an ice cube or applying an ice pack directly to the nose may reduce nasal blood flow.

If bleeding stops with first aid measures, it is recommended to apply a topical antiseptic preparation to reduce crusting and vestibulitis. Naseptin cream (containing chlorhexidine and neomycin) is commonly used and should be applied to the nostrils four times daily for 10 days.

Enzyme-inducing anticonvulsants have been found to enhance the metabolism of ethinyl estradiol and progestogens. This increased breakdown diminishes the effectiveness of the oral contraceptive pill (OCP) in preventing pregnancy. Some examples of enzyme-inducing anticonvulsants include carbamazepine, phenytoin, phenobarbitol, and topiramate.

On the other hand, non-enzyme-inducing anticonvulsants are unlikely to have an impact on contraception. Some examples of these anticonvulsants are sodium valproate, clonazepam, gabapentin, levetiracetam, and piracetam.

It is important to note that lamotrigine, although classified as a non-enzyme-inducing anticonvulsant, requires special consideration. While there is no evidence suggesting that the OCP directly affects epilepsy, there is evidence indicating that it reduces the levels of lamotrigine in the bloodstream. This reduction in lamotrigine levels could potentially compromise seizure control and increase the likelihood of experiencing seizures.

One of the signs of digoxin toxicity is yellow-green vision. Other clinical features include feeling generally unwell, lethargy, nausea and vomiting, loss of appetite, confusion, and the development of arrhythmias such as AV block and bradycardia.

Further Reading:

Digoxin is a medication used for rate control in atrial fibrillation and for improving symptoms in heart failure. It works by decreasing conduction through the atrioventricular node and increasing the force of cardiac muscle contraction. However, digoxin toxicity can occur, and plasma concentration alone does not determine if a patient has developed toxicity. Symptoms of digoxin toxicity include feeling generally unwell, lethargy, nausea and vomiting, anorexia, confusion, yellow-green vision, arrhythmias, and gynaecomastia.

ECG changes seen in digoxin toxicity include downsloping ST depression with a characteristic Salvador Dali sagging appearance, flattened, inverted, or biphasic T waves, shortened QT interval, mild PR interval prolongation, and prominent U waves. There are several precipitating factors for digoxin toxicity, including hypokalaemia, increasing age, renal failure, myocardial ischaemia, electrolyte imbalances, hypoalbuminaemia, hypothermia, hypothyroidism, and certain medications such as amiodarone, quinidine, verapamil, and diltiazem.

Management of digoxin toxicity involves the use of digoxin specific antibody fragments, also known as Digibind or digifab. Arrhythmias should be treated, and electrolyte disturbances should be corrected with close monitoring of potassium levels. It is important to note that digoxin toxicity can be precipitated by hypokalaemia, and toxicity can then lead to hyperkalaemia.

The 30-point Folstein mini-mental state examination (MMSE) includes a task where the examiner asks the individual to repeat back a phrase. However, this task is not included in the AMTS. The AMTS consists of ten questions that assess different aspects of cognitive function. These questions cover topics such as age, time, year, location, recognition of people, date of birth, historical events, present monarch or prime minister, counting backwards, and recall of an address. The AMTS is a useful tool for evaluating memory loss and is referenced in the RCEM syllabus.

If IV methylene blue is obtained, it is typically used to treat a specific cause. However, if there is no response to methylene blue, alternative treatments such as hyperbaric oxygen or exchange transfusion may be considered. In cases where the cause is NADH-methaemoglobinaemia reductase deficiency, ascorbic acid can be used as a potential treatment.

Further Reading:

Methaemoglobinaemia is a condition where haemoglobin is oxidised from Fe2+ to Fe3+. This process is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin, converting it back to haemoglobin. In healthy individuals, methaemoglobin levels are typically less than 1% of total haemoglobin. However, an increase in methaemoglobin can lead to tissue hypoxia as Fe3+ cannot bind oxygen effectively.

Methaemoglobinaemia can be congenital or acquired. Congenital causes include haemoglobin chain variants (HbM, HbH) and NADH methaemoglobin reductase deficiency. Acquired causes can be due to exposure to certain drugs or chemicals, such as sulphonamides, local anaesthetics (especially prilocaine), nitrates, chloroquine, dapsone, primaquine, and phenytoin. Aniline dyes are also known to cause methaemoglobinaemia.

Clinical features of methaemoglobinaemia include slate grey cyanosis (blue to grey skin coloration), chocolate blood or chocolate cyanosis (brown color of blood), dyspnoea, low SpO2 on pulse oximetry (which often does not improve with supplemental oxygen), and normal PaO2 on arterial blood gas (ABG) but low SaO2. Patients may tolerate hypoxia better than expected. Severe cases can present with acidosis, arrhythmias, seizures, and coma.

Diagnosis of methaemoglobinaemia is made by directly measuring the level of methaemoglobin using a co-oximeter, which is present in most modern blood gas analysers. Other investigations, such as a full blood count (FBC), electrocardiogram (ECG), chest X-ray (CXR), and beta-human chorionic gonadotropin (bHCG) levels (in pregnancy), may be done to assess the extent of the condition and rule out other contributing factors.

Active treatment is required if the methaemoglobin level is above 30% or if it is below 30% but the patient is symptomatic or shows evidence of tissue hypoxia. Treatment involves maintaining the airway and delivering high-flow oxygen, removing the causative agents, treating toxidromes and consider giving IV dextrose 5%.

Parkinson’s disease is primarily characterized by the degeneration of cells in the substantia nigra, a region located in the midbrain. The most severely affected part is the pars compacta, which plays a crucial role in motor control. As a result, there is a significant decrease in the activity of cells that secrete dopamine.

The main symptoms of Parkinson’s disease include tremors that occur when the body is at rest, rigidity in the muscles, and bradykinesia, which refers to a slowness in movement. These symptoms can greatly impact a person’s ability to perform everyday tasks and can progressively worsen over time.

The therapeutic range for carbamazepine is between 4 and 10 mg/L. This range indicates the optimal concentration of the medication in the bloodstream for it to be effective in treating certain conditions. It is important for healthcare professionals to monitor the levels of carbamazepine in a patient’s blood to ensure they are within this range. If the levels are too low, the medication may not be effective, while levels that are too high can lead to potential side effects. By maintaining carbamazepine levels within the therapeutic range, healthcare providers can maximize the benefits of the medication while minimizing any potential risks.