To insert an IJV line, the patient should be positioned in the Trendelenburg position. This means that the patient should lie on their back with their head tilted down by at least 15 degrees. Additionally, the patient’s head should be turned away or laterally rotated from the side where the cannulation will take place. This positioning helps to distend the neck veins, making it easier to access them for the procedure.

Further Reading:

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

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

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

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

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

Acne conglobata is an extremely severe form of acne where acne nodules come together and create sinuses. Acne fulminans, on the other hand, is a rare and severe complication of acne conglobata that is accompanied by systemic symptoms. It is linked to elevated levels of androgenic hormones, specific autoimmune conditions, and a genetic predisposition.

The typical clinical characteristics of acne fulminans are as follows:

– Sudden and abrupt onset
– Inflammatory and ulcerated nodular acne primarily found on the chest and back
– Often painful lesions
– Ulcers on the upper trunk covered with bleeding crusts
– Severe acne scarring
– Fluctuating fever
– Painful joints and arthropathy
– General feeling of illness (malaise)
– Loss of appetite and weight loss
– Enlarged liver and spleen (hepatosplenomegaly)

It is crucial to refer patients immediately for a specialist evaluation and hospital admission. Treatment options for acne fulminans include systemic corticosteroids, dapsone, ciclosporin, and high-dose intravenous antibiotics.

Acute kidney injury (AKI), previously known as acute renal failure, is a sudden decline in kidney function. This leads to the accumulation of urea and other waste products in the body, as well as disturbances in fluid balance and electrolyte levels. 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.

AKI is categorized into three stages based on specific criteria. In stage 1, there is a rise in creatinine levels of 26 micromol/L or more within 48 hours, or a rise of 50-99% from baseline within 7 days (1.5-1.99 times the baseline). Additionally, a urine output of less than 0.5 mL/kg/hour for more than 6 hours is indicative of stage 1 AKI.

Stage 2 AKI is characterized by a creatinine rise of 100-199% from baseline within 7 days (2.0-2.99 times the baseline), or a urine output of less than 0.5 mL/kg/hour for more than 12 hours.

In stage 3 AKI, there is a creatinine rise of 200% or more from baseline within 7 days (3.0 or more times the baseline). Alternatively, a creatinine rise to 354 micromol/L or more with an acute rise of 26 micromol/L or more within 48 hours, or a rise of 50% or more within 7 days, is indicative of stage 3 AKI. Additionally, a urine output of less than 0.3 mL/kg/hour for 24 hours or anuria (no urine output) for 12 hours also falls under stage 3 AKI.

The use of low-dose aspirin during pregnancy is considered safe and can be used to manage recurrent miscarriage, clotting disorders, and pre-eclampsia. On the other hand, high-dose aspirin carries several risks, especially if used in the third trimester. These risks include delayed onset of labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus (a condition that affects the brain due to high levels of bilirubin). Additionally, there is a slight increase in the risk of first-trimester abortion if high-dose aspirin is used early in pregnancy.

Below is a list outlining commonly encountered drugs that have adverse effects during pregnancy:

Drug: ACE inhibitors (e.g. ramipril)
Adverse effects: If given in the second and third trimester, ACE inhibitors can cause hypoperfusion, renal failure, and the oligohydramnios sequence.

Drug: Aminoglycosides (e.g. gentamicin)
Adverse effects: Aminoglycosides can cause ototoxicity (damage to the ear) and deafness.

Drug: Aspirin
Adverse effects: High doses of aspirin can cause first-trimester abortions, delayed onset of labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. However, low doses (e.g. 75 mg) have no significant associated risk.

Gilbert’s syndrome is the most common hereditary cause of elevated bilirubin levels and can be found in up to 5% of the population. It is characterized by an isolated increase in unconjugated bilirubin without any detectable liver disease. In most cases, it is inherited in an autosomal recessive manner, although there have been some instances of autosomal dominant inheritance, particularly in Asian populations.

The elevated bilirubin levels in Gilbert’s syndrome do not have any serious consequences and typically occur during times of stress, physical exertion, fasting, or infection. While it is often asymptomatic, some individuals may experience symptoms such as fatigue, decreased appetite, nausea, and abdominal pain.

The underlying cause of the elevated bilirubin levels is a decrease in the activity of the enzyme glucuronyltransferase, which is responsible for conjugating bilirubin. In Gilbert’s syndrome, the bilirubin levels are generally less than three times the upper limit of normal, with more than 70% of the bilirubin being unconjugated. Liver function tests and LDH (lactate dehydrogenase) levels are typically within the normal range.

Paracetamol overdose is the most common overdose in the U.K. and is also the leading cause of acute liver failure. The liver damage occurs due to a metabolite of paracetamol called N-acetyl-p-benzoquinoneimine (NAPQI), which depletes the liver’s glutathione stores and directly harms liver cells. Severe liver damage and even death can result from an overdose of more than 12 g or > 150 mg/kg body weight.

The clinical manifestations of paracetamol overdose can be divided into four stages:

Stage 1 (0-24 hours): Patients may not show any symptoms, but common signs include nausea, vomiting, and abdominal discomfort.

Stage 2 (24-48 hours): Right upper quadrant pain and tenderness develop, along with the possibility of hypoglycemia and reduced consciousness.

Stage 3 (48-96 hours): Hepatic failure begins, characterized by jaundice, coagulopathy, and encephalopathy. Loin pain, haematuria, and proteinuria may indicate early renal failure.

Stage 4 (> 96 hours): Hepatic failure worsens progressively, leading to cerebral edema, disseminated intravascular coagulation (DIC), and ultimately death.

The earliest and most sensitive indicator of liver damage is a prolonged INR, which starts to rise approximately 24 hours after the overdose. Liver function tests (LFTs) typically remain normal until 18 hours after the overdose. However, AST and ALT levels then sharply increase and can exceed 10,000 units/L by 72-96 hours. Bilirubin levels rise more slowly and peak around 5 days.

The primary treatment for paracetamol overdose is acetylcysteine. Acetylcysteine is a highly effective antidote, but its efficacy diminishes rapidly if administered more than 8 hours after a significant ingestion. Ingestions exceeding 75 mg/kg are considered significant.

Acetylcysteine should be given based on a 4-hour level or administered empirically if the presentation occurs more than 8 hours after a significant overdose. If the overdose is staggered or the timing is uncertain, empirical treatment is also recommended. The treatment regimen is as follows:

– First dose: 150 mg/kg in 200 mL 5% glucose over 1 hour
– Second dose 50 mg/kg in 500 mL 5% glucose over 4 hours
– Third dose 100 mg/kg in 1000 mL 5% glucose over 16 hours

Paracetamol overdose is the most common overdose in the U.K. and is also the leading cause of acute liver failure. The liver damage occurs due to a metabolite of paracetamol called N-acetyl-p-benzoquinoneimine (NAPQI), which depletes the liver’s glutathione stores and directly harms liver cells. Severe liver damage and even death can result from an overdose of more than 12 g or > 150 mg/kg body weight.

The clinical manifestations of paracetamol overdose can be divided into four stages:

Stage 1 (0-24 hours): Patients may not show any symptoms, but common signs include nausea, vomiting, and abdominal discomfort.

Stage 2 (24-48 hours): Right upper quadrant pain and tenderness develop, along with the possibility of hypoglycemia and reduced consciousness.

Stage 3 (48-96 hours): Hepatic failure begins, characterized by jaundice, coagulopathy, and encephalopathy. Loin pain, haematuria, and proteinuria may indicate early renal failure.

Stage 4 (> 96 hours): Hepatic failure worsens progressively, leading to cerebral edema, disseminated intravascular coagulation (DIC), and ultimately death.

The earliest and most sensitive indicator of liver damage is a prolonged INR, which starts to rise approximately 24 hours after the overdose. Liver function tests (LFTs) typically remain normal until 18 hours after the overdose. However, AST and ALT levels then sharply increase and can exceed 10,000 units/L by 72-96 hours. Bilirubin levels rise more slowly and peak around 5 days.

The primary treatment for paracetamol overdose is acetylcysteine. Acetylcysteine is a highly effective antidote, but its efficacy diminishes rapidly if administered more than 8 hours after a significant ingestion. Ingestions exceeding 75 mg/kg are considered significant.

Acetylcysteine should be given based on a 4-hour level or administered empirically if the presentation occurs more than 8 hours after a significant overdose. If the overdose is staggered or the timing is uncertain, empirical treatment is also recommended. The treatment regimen is as follows:

– First dose: 150 mg/kg in 200 mL 5% glucose over 1 hour
– Second dose 50 mg/kg in 500 mL 5% glucose over 4 hours
– Third dose 100 mg/kg in 1000 mL 5% glucose over 16 hours

Low-velocity gunshot wounds to the abdomen result in tissue damage through laceration and cutting. On the other hand, high-velocity gunshot wounds transfer a greater amount of kinetic energy to the abdominal viscera. These types of wounds can cause more extensive damage in the surrounding area of the missile’s path due to temporary cavitation.

When patients experience penetrating abdominal trauma as a result of gunshot wounds, certain organs are more commonly injured. The small bowel is affected in approximately 50% of cases, followed by the colon in 40% of cases. The liver is injured in around 30% of cases, while abdominal vascular structures are affected in about 25% of cases.

Please note that these statistics have been obtained from the most recent edition of the ATLS manual.

Acute cholecystitis occurs when a stone becomes stuck in the outlet of the gallbladder, causing irritation of the wall and resulting in chemical cholecystitis. This leads to the accumulation of pus within the gallbladder, which is typically sterile at first. However, there is a possibility of secondary infection with enteric organisms like Escherichia coli and Klebsiella spp.

The clinical features of acute cholecystitis include severe pain in the right upper quadrant or epigastrium, which can radiate to the back and lasts for more than 12 hours. Fevers and rigors are often present, along with common symptoms like nausea and vomiting. Murphy’s sign is a useful diagnostic tool, as it has a high sensitivity and positive predictive value for acute cholecystitis. However, its specificity is lower, as it can also be positive in biliary colic and ascending cholangitis.

In cases of acute cholecystitis, the white cell count and C-reactive protein (CRP) levels are usually elevated. AST, ALT, and ALP may also show elevation, but they can often be within the normal range. Bilirubin levels may be mildly elevated, but they can also be normal. If there is a significant increase in AST, ALT, ALP, and/or bilirubin, it may indicate the presence of other biliary tract conditions such as ascending cholangitis or choledocholithiasis.

It is important to note that there is some overlap in the presentation of biliary colic, acute cholecystitis, and ascending cholangitis. To differentiate between these diagnoses, the following list can be helpful:

Biliary colic:
– Pain duration: Less than 12 hours
– Fever: Absent
– Murphy’s sign: Negative
– WCC & CRP: Normal
– AST, ALT & ALP: Normal
– Bilirubin: Normal

Acute cholecystitis:
– Pain duration: More than 12 hours
– Fever: Present
– Murphy’s sign: Positive
– WCC & CRP: Elevated
– AST, ALT & ALP: Normal or mildly elevated
– Bilirubin: Normal or mildly elevated

Ascending cholangitis:
– Pain duration: Variable
– Fever: Present
– Murphy’s sign: Negative
– WCC & CRP: Elevated
– AST, ALT & ALP: Elevated

Transfusion transmitted bacterial infection is a rare complication that can occur during blood transfusion. It is more commonly associated with platelet transfusion, as platelets are stored at room temperature. Additionally, previously frozen components that are thawed using a water bath and red cell components stored for several weeks are also at a higher risk for bacterial infection.

Both Gram-positive and Gram-negative bacteria have been implicated in transfusion-transmitted bacterial infection, but Gram-negative bacteria are known to cause more severe illness and have higher rates of morbidity and mortality. Among the bacterial organisms, Yersinia enterocolitica is the most commonly associated with this type of infection. This particular organism is able to multiply at low temperatures and utilizes iron as a nutrient, making it well-suited for proliferation in blood stores.

The clinical features of transfusion-transmitted bacterial infection typically manifest shortly after the transfusion begins. These features include a high fever, chills and rigors, nausea and vomiting, tachycardia, hypotension, and even circulatory collapse.

If there is suspicion of a transfusion-transmitted bacterial infection, it is crucial to immediately stop the transfusion. Blood cultures and a Gram-stain should be requested to identify the specific bacteria causing the infection. Broad-spectrum antibiotics should be initiated promptly. Furthermore, the blood pack should be returned to the blood bank urgently for culture and Gram-stain analysis.

A threatened miscarriage happens when there is bleeding during the first trimester of pregnancy, but no fetal tissue has been expelled, and the opening of the cervix is closed.

If cervical dilatation occurs, a threatened miscarriage can progress to become an inevitable miscarriage. In this case, the pain and bleeding are usually more intense, and upon examination, the cervix will be found to be open.

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

Respiratory acidosis is often associated with chronic obstructive pulmonary disease (COPD) or life-threatening asthma. Other causes include pulmonary edema, sedative drug overdose (such as opiates or benzodiazepines), neuromuscular disease, obesity, or certain medications.

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

Metabolic acidosis with a raised anion gap can be caused by conditions like lactic acidosis (which can result from hypoxemia, shock, sepsis, or infarction) or ketoacidosis (commonly seen in diabetes, starvation, or alcohol excess). Other causes include renal failure or poisoning (such as late stages of aspirin overdose, methanol, or ethylene glycol).

Metabolic acidosis with a normal anion gap can be attributed to conditions like renal tubular acidosis, diarrhea, ammonium chloride ingestion, or adrenal insufficiency.

Corticosteroids can be beneficial in preventing or reducing prolonged reactions. According to the current APLS guidelines, the recommended doses of hydrocortisone for different age groups are as follows:

– Children under 6 months: 25 mg administered slowly via intramuscular (IM) or intravenous (IV) route.
– Children aged 6 months to 6 years: 50 mg administered slowly via IM or IV route.
– Children aged 6 to 12 years: 100 mg administered slowly via IM or IV route.
– Children over 12 years: 200 mg administered slowly via IM or IV route.
– Adults: 200 mg administered slowly via IM or IV route.

It is important to note that the most recent ALS guidelines do not recommend the routine use of corticosteroids for treating anaphylaxis in adults. However, the current APLS guidelines still advocate for the use of corticosteroids in children to manage anaphylaxis.

In the treatment of diabetic ketoacidosis (DKA), it is important to continue the infusion of insulin until certain criteria are met. These criteria include ketone levels being less than 0.3 mmol/L and the pH of the blood being above 7.3 or the bicarbonate levels being above 18 mmol/L. Additionally, the patient should feel comfortable enough to eat at this point. It is crucial not to stop the intravenous insulin infusion until at least 30 minutes after administering subcutaneous short-acting insulin.

Further Reading:

Diabetic ketoacidosis (DKA) is a serious complication of diabetes that occurs due to a lack of insulin in the body. It is most commonly seen in individuals with type 1 diabetes but can also occur in type 2 diabetes. DKA is characterized by hyperglycemia, acidosis, and ketonaemia.

The pathophysiology of DKA involves insulin deficiency, which leads to increased glucose production and decreased glucose uptake by cells. This results in hyperglycemia and osmotic diuresis, leading to dehydration. Insulin deficiency also leads to increased lipolysis and the production of ketone bodies, which are acidic. The body attempts to buffer the pH change through metabolic and respiratory compensation, resulting in metabolic acidosis.

DKA can be precipitated by factors such as infection, physiological stress, non-compliance with insulin therapy, acute medical conditions, and certain medications. The clinical features of DKA include polydipsia, polyuria, signs of dehydration, ketotic breath smell, tachypnea, confusion, headache, nausea, vomiting, lethargy, and abdominal pain.

The diagnosis of DKA is based on the presence of ketonaemia or ketonuria, blood glucose levels above 11 mmol/L or known diabetes mellitus, and a blood pH below 7.3 or bicarbonate levels below 15 mmol/L. Initial investigations include blood gas analysis, urine dipstick for glucose and ketones, blood glucose measurement, and electrolyte levels.

Management of DKA involves fluid replacement, electrolyte correction, insulin therapy, and treatment of any underlying cause. Fluid replacement is typically done with isotonic saline, and potassium may need to be added depending on the patient’s levels. Insulin therapy is initiated with an intravenous infusion, and the rate is adjusted based on blood glucose levels. Monitoring of blood glucose, ketones, bicarbonate, and electrolytes is essential, and the insulin infusion is discontinued once ketones are below 0.3 mmol/L, pH is above 7.3, and bicarbonate is above 18 mmol/L.

Complications of DKA and its treatment include gastric stasis, thromboembolism, electrolyte disturbances, cerebral edema, hypoglycemia, acute respiratory distress syndrome, and acute kidney injury. Prompt medical intervention is crucial in managing DKA to prevent potentially fatal outcomes.

Infectious mononucleosis is typically a self-limiting infection that is primarily caused by the Epstein-Barr virus (EBV), a member of the human herpesvirus family. About 10% of cases are caused by cytomegalovirus (CMV) infection.

This clinical infection is most commonly observed in populations with a large number of young adults, such as university students and active-duty military personnel.

The main clinical features of infectious mononucleosis include a low-grade fever, fatigue, prolonged malaise, sore throat (often accompanied by tonsillar enlargement and exudate), a transient, fine, non-itchy rash, lymphadenopathy (most commonly in the cervical region), arthralgia and myalgia, mild enlargement of the liver and spleen, and jaundice (which is less common in young adults but more prevalent in the elderly).

To diagnose EBV infectious mononucleosis, a variety of unrelated non-EBV heterophile antibodies and specific EBV antibodies can be used.

1. Heterophile antibodies:
Around 70-90% of patients with EBV infectious mononucleosis produce heterophile antibodies, which are antibodies that react against antigens from other species. False positives can occur with hepatitis, malaria, toxoplasmosis, rubella, systemic lupus erythematosus (SLE), lymphoma, and leukemia. Two main screening tests can detect these antibodies and provide rapid results within a day:
– Paul-Bunnell test: Sheep red blood cells agglutinate in the presence of heterophile antibodies.
– Monospot test: Horse red blood cells agglutinate in the presence of heterophile antibodies.

2. EBV-specific antibodies:
Patients who remain heterophile-negative after six weeks are considered heterophile-negative and should be tested for EBV-specific antibodies. These antibodies are also useful in cases where a false positive heterophile antibody test is suspected.

Other useful investigations include a full blood count, which often shows a raised white cell count with lymphocytosis and atypical lymphocytes in more than 20% of cases, an elevated erythrocyte sedimentation rate (ESR) in most patients, liver function tests (LFTs) that may show mild elevation of serum transaminases, throat swabs to rule out group A streptococci pharyngitis as a differential diagnosis, and abdominal ultrasound if splenomegaly is present.

The typical range for the partial pressure of carbon dioxide (pCO2) is 4.4-6.4 kilopascals (kPa). In terms of arterial blood gas (ABG) results, the normal range for pO2 (partial pressure of oxygen) is 10-14.4 kPa or 70-100 millimeters of mercury (mmHg). The normal range for pCO2 is 4.4-6.4 kPa or 35-45 mmHg. Additionally, the normal range for bicarbonate levels is 23-28 millimoles per liter (mmol/L).

Further Reading:

Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.

To reduce the risk of harm to the patient, it is important to test for collateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.

Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.

The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.

The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.

The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.

Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.

The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.

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.

Hypertension, hyperglycemia, weight gain, truncal obesity, supraclavicular fat pads, and striae are characteristic symptoms of a Cushing syndrome.

Further Reading:

Cushing’s syndrome is a clinical syndrome caused by prolonged exposure to high levels of glucocorticoids. The severity of symptoms can vary depending on the level of steroid exposure. There are two main classifications of Cushing’s syndrome: ACTH-dependent disease and non-ACTH-dependent disease. ACTH-dependent disease is caused by excessive ACTH production from the pituitary gland or ACTH-secreting tumors, which stimulate excessive cortisol production. Non-ACTH-dependent disease is characterized by excess glucocorticoid production independent of ACTH stimulation.

The most common cause of Cushing’s syndrome is exogenous steroid use. Pituitary adenoma is the second most common cause and the most common endogenous cause. Cushing’s disease refers specifically to Cushing’s syndrome caused by an ACTH-producing pituitary tumor.

Clinical features of Cushing’s syndrome include truncal obesity, supraclavicular fat pads, buffalo hump, weight gain, moon facies, muscle wasting and weakness, diabetes or impaired glucose tolerance, gonadal dysfunction, hypertension, nephrolithiasis, skin changes (such as skin atrophy, striae, easy bruising, hirsutism, acne, and hyperpigmentation in ACTH-dependent causes), depression and emotional lability, osteopenia or osteoporosis, edema, irregular menstrual cycles or amenorrhea, polydipsia and polyuria, poor wound healing, and signs related to the underlying cause, such as headaches and visual problems.

Diagnostic tests for Cushing’s syndrome include 24-hour urinary free cortisol, 1 mg overnight dexamethasone suppression test, and late-night salivary cortisol. Other investigations aim to assess metabolic disturbances and identify the underlying cause, such as plasma ACTH, full blood count (raised white cell count), electrolytes, and arterial blood gas analysis. Imaging, such as CT or MRI of the abdomen, chest, and/or pituitary, may be required to assess suspected adrenal tumors, ectopic ACTH-secreting tumors, and pituitary tumors. The choice of imaging is guided by the ACTH result, with undetectable ACTH and elevated serum cortisol levels indicating ACTH-independent Cushing’s syndrome and raised ACTH suggesting an ACTH-secreting tumor.

The BTS guidelines for acute asthma in children recommend administering oral steroids early in the treatment of asthma attacks. It is advised to give a dose of 20 mg prednisolone for children aged 2–5 years and a dose of 30–40 mg for children over 5 years old. If a child is already taking maintenance steroid tablets, they should receive 2 mg/kg prednisolone, up to a maximum dose of 60 mg. If a child vomits after taking the medication, the dose of prednisolone should be repeated. In cases where a child is unable to keep down orally ingested medication, intravenous steroids should be considered. Typically, treatment for up to three days is sufficient, but the duration of the course should be adjusted based on the time needed for recovery. Tapering off the medication is not necessary unless the steroid course exceeds 14 days. For more information, refer to the BTS/SIGN Guideline on the Management of Asthma.

Congenital adrenal hyperplasia (CAH) is a group of inherited disorders that are caused by autosomal recessive genes. The majority of affected patients, over 90%, have a deficiency of the enzyme 21-hydroxylase. This enzyme is encoded by the 21-hydroxylase gene, which is located on chromosome 6p21 within the HLA histocompatibility complex. The second most common cause of CAH is a deficiency of the enzyme 11-beta-hydroxylase. The condition is rare, with an incidence of approximately 1 in 500 births in the UK. It is more prevalent in the offspring of consanguineous marriages.

The deficiency of 21-hydroxylase leads to a deficiency of cortisol and/or aldosterone, as well as an excess of precursor steroids. As a result, there is an increased secretion of ACTH from the anterior pituitary, leading to adrenocortical hyperplasia.

The severity of CAH varies depending on the degree of 21-hydroxylase deficiency. Female infants often exhibit ambiguous genitalia, such as clitoral hypertrophy and labial fusion. Male infants may have an enlarged scrotum and/or scrotal pigmentation. Hirsutism, or excessive hair growth, occurs in 10% of cases.

Boys with CAH often experience a salt-losing adrenal crisis at around 1-3 weeks of age. This crisis is characterized by symptoms such as vomiting, weight loss, floppiness, and circulatory collapse.

The diagnosis of CAH can be made by detecting markedly elevated levels of the metabolic precursor 17-hydroxyprogesterone. Neonatal screening is possible through the detection of persistently elevated 17-hydroxyprogesterone.

In infants presenting with a salt-losing crisis, the following biochemical abnormalities are typically observed: hyponatremia (low sodium levels), hyperkalemia (high potassium levels), metabolic acidosis, and hypoglycemia.

Boys experiencing a salt-losing crisis will require fluid resuscitation, intravenous dextrose, and intravenous hydrocortisone. Affected females may require corrective surgery for their external genitalia. However, they have an intact uterus and ovaries and are able to have children.

The long-term management of CAH involves lifelong replacement of hydrocortisone to suppress ACTH levels.

The maximum safe dose of plain lidocaine is 3 mg per kilogram of body weight, with a maximum limit of 200 mg. However, when administered with adrenaline 1:200,000, the maximum safe dose increases to 7 mg per kilogram of body weight, with a maximum limit of 500 mg.

For example, if a patient weighs 70 kg, the maximum safe dose of lidocaine hydrochloride would be 210 mg. However, according to the British National Formulary (BNF), the maximum safe dose is actually 200 mg.

For more information on lidocaine hydrochloride, please refer to the BNF section dedicated to this medication.

Ketamine should not be used in children under 12 months old due to the increased risk of laryngospasm and airway complications. The Royal College of Emergency Medicine advises against using ketamine in children under 1 year old in the emergency department, and it should only be administered by experienced clinicians in children aged 5 and under. Ketamine may cause a slight increase in blood pressure and heart rate, making it a suitable option for those with low blood pressure. However, it is contraindicated in individuals with malignant hypertension (blood pressure above 180 mmHg). Please refer to the notes below for additional contraindications.

Further Reading:

Procedural sedation is commonly used by emergency department (ED) doctors to minimize pain and discomfort during procedures that may be painful or distressing for patients. Effective procedural sedation requires the administration of analgesia, anxiolysis, sedation, and amnesia. This is typically achieved through the use of a combination of short-acting analgesics and sedatives.

There are different levels of sedation, ranging from minimal sedation (anxiolysis) to general anesthesia. It is important for clinicians to understand the level of sedation being used and to be able to manage any unintended deeper levels of sedation that may occur. Deeper levels of sedation are similar to general anesthesia and require the same level of care and monitoring.

Various drugs can be used for procedural sedation, including propofol, midazolam, ketamine, and fentanyl. Each of these drugs has its own mechanism of action and side effects. Propofol is commonly used for sedation, amnesia, and induction and maintenance of general anesthesia. Midazolam is a benzodiazepine that enhances the effect of GABA on the GABA A receptors. Ketamine is an NMDA receptor antagonist and is used for dissociative sedation. Fentanyl is a highly potent opioid used for analgesia and sedation.

The doses of these drugs for procedural sedation in the ED vary depending on the drug and the route of administration. It is important for clinicians to be familiar with the appropriate doses and onset and peak effect times for each drug.

Safe sedation requires certain requirements, including appropriate staffing levels, competencies of the sedating practitioner, location and facilities, and monitoring. The level of sedation being used determines the specific requirements for safe sedation.

After the procedure, patients should be monitored until they meet the criteria for safe discharge. This includes returning to their baseline level of consciousness, having vital signs within normal limits, and not experiencing compromised respiratory status. Pain and discomfort should also be addressed before discharge.

Gallstone ileus occurs when a gallstone becomes stuck in the small intestine, specifically at the caeco-ileal valve. This condition presents with similar symptoms to other causes of small bowel obstruction. Patients may experience colicky central abdominal pain, which can have a gradual onset. Vomiting is common and tends to occur earlier in the course of the illness compared to large bowel obstruction. Abdominal distension and the absence of flatus are also typical signs. Additionally, there may be a lack of normal bowel sounds or the presence of high-pitched tinkling sounds. A mass in the right upper quadrant of the abdomen may be palpable.

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.

This woman is displaying symptoms and signs that are consistent with a diagnosis of meningococcal septicaemia. In the United Kingdom, the majority of cases of meningococcal septicaemia are caused by Neisseria meningitidis group B.

In the prehospital setting, the most suitable medication and method of administration is intramuscular benzylpenicillin 1.2 g. This medication is commonly carried by most General Practitioners and is easier to administer than an intravenous drug in these circumstances.

For close household contacts, prophylaxis can be provided in the form of oral rifampicin 600 mg twice daily for two days.

The primary treatment option for hypertensive encephalopathy, a condition characterized by sudden confusion, severe headache, and coordination problems due to significantly elevated blood pressure, is labetalol.

Further Reading:

A hypertensive emergency is characterized by a significant increase in blood pressure accompanied by acute or progressive damage to organs. While there is no specific blood pressure value that defines a hypertensive emergency, systolic blood pressure is typically above 180 mmHg and/or diastolic blood pressure is above 120 mmHg. The most common presentations of hypertensive emergencies include cerebral infarction, pulmonary edema, encephalopathy, and congestive cardiac failure. Less common presentations include intracranial hemorrhage, aortic dissection, and pre-eclampsia/eclampsia.

The signs and symptoms of hypertensive emergencies can vary widely due to the potential dysfunction of every physiological system. Some common signs and symptoms include headache, nausea and/or vomiting, chest pain, arrhythmia, proteinuria, signs of acute kidney failure, epistaxis, dyspnea, dizziness, anxiety, confusion, paraesthesia or anesthesia, and blurred vision. Clinical assessment focuses on detecting acute or progressive damage to the cardiovascular, renal, and central nervous systems.

Investigations that are essential in evaluating hypertensive emergencies include U&Es (electrolyte levels), urinalysis, ECG, and CXR. Additional investigations may be considered depending on the suspected underlying cause, such as a CT head for encephalopathy or new onset confusion, CT thorax for suspected aortic dissection, and CT abdomen for suspected phaeochromocytoma. Plasma free metanephrines, urine total catecholamines, vanillylmandelic acid (VMA), and metanephrine may be tested if phaeochromocytoma is suspected. Urine screening for cocaine and/or amphetamines may be appropriate in certain cases, as well as an endocrine screen for Cushing’s syndrome.

The management of hypertensive emergencies involves cautious reduction of blood pressure to avoid precipitating renal, cerebral, or coronary ischemia. Staged blood pressure reduction is typically the goal, with an initial reduction in mean arterial pressure (MAP) by no more than 25% in the first hour. Further gradual reduction to a systolic blood pressure of 160 mmHg and diastolic blood pressure of 100 mmHg over the next 2 to 6 hours is recommended. Initial management involves treatment with intravenous antihypertensive agents in an intensive care setting with appropriate monitoring.

When a complete quadriceps rupture occurs, it leads to the inability to actively extend the knee. Please refer to the following notes for more detailed information.

Further Reading:

A quadriceps tendon tear or rupture is a traumatic lower limb and joint injury that occurs when there is heavy loading on the leg, causing forced contraction of the quadriceps while the foot is planted and the knee is partially bent. These tears most commonly happen at the osteotendinous junction between the tendon and the superior pole of the patella. Quadriceps tendon ruptures are more common than patellar tendon ruptures.

When a quadriceps tendon tear occurs, the patient usually experiences a tearing sensation and immediate pain. They will then typically complain of pain around the knee and over the tendon. Clinically, there will often be a knee effusion and weakness or inability to actively extend the knee.

In cases of complete quadriceps tears, the patella will be displaced distally, resulting in a low lying patella or patella infera, also known as patella baja. Radiological measurements, such as the Insall-Salvati ratio, can be used to measure patella height. The Insall-Salvati ratio is calculated by dividing the patellar tendon length by the patellar length. A normal ratio is between 0.8 to 1.2, while a low lying patella (patella baja) is less than 0.8 and a high lying patella (patella alta) is greater than 1.2.

If an adult with a head injury experiences more than one episode of vomiting, it is recommended to undergo a CT scan of the head. There are several criteria for an urgent CT scan in individuals with a head injury, including a Glasgow Coma Scale (GCS) score of less than 13 on initial assessment in the emergency department (ED), a GCS score of less than 15 at 2 hours after the injury on assessment in the ED, suspected open or depressed skull fracture, any sign of basal skull fracture (such as haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, or Battle’s sign), post-traumatic seizure, new focal neurological deficit, and being on anticoagulation medication. If any of these signs are present, a CT scan should be performed within 1 hour, except for patients on anticoagulation medication who should undergo a CT scan within 8 hours if none of the other signs are present. However, if a patient on anticoagulation medication has any of the other signs, the CT scan should be performed within 1 hour.

Further Reading:

Indications for CT Scanning in Head Injuries (Adults):
– CT head scan should be performed within 1 hour if any of the following features are present:
– GCS < 13 on initial assessment in the ED
– GCS < 15 at 2 hours after the injury on assessment in the ED
– Suspected open or depressed skull fracture
– Any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign)
– Post-traumatic seizure
– New focal neurological deficit
– > 1 episode of vomiting

Indications for CT Scanning in Head Injuries (Children):
– CT head scan should be performed within 1 hour if any of the features in List 1 are present:
– Suspicion of non-accidental injury
– Post-traumatic seizure but no history of epilepsy
– GCS < 14 on initial assessment in the ED for children more than 1 year of age
– Paediatric GCS < 15 on initial assessment in the ED for children under 1 year of age
– At 2 hours after the injury, GCS < 15
– Suspected open or depressed skull fracture or tense fontanelle
– Any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign)
– New focal neurological deficit
– For children under 1 year, presence of bruise, swelling or laceration of more than 5 cm on the head

– CT head scan should be performed within 1 hour if none of the above features are present but two or more of the features in List 2 are present:
– Loss of consciousness lasting more than 5 minutes (witnessed)
– Abnormal drowsiness
– Three or more discrete episodes of vomiting
– Dangerous mechanism of injury (high-speed road traffic accident, fall from a height.

Chancroid is a sexually transmitted infection caused by the bacteria Haemophilus ducreyi. It is not very common in the UK but is prevalent in Africa, Asia, and South America. HIV is often associated with chancroid, particularly in Africa where there is a 60% correlation.

The main symptom of chancroid is the development of painful ulcers on the genitalia. In women, these ulcers typically appear on the labia majora. Sometimes, kissing ulcers can form when ulcers are located on opposing surfaces of the labia. Painful swelling of the lymph nodes occurs in 30-60% of patients, and in some cases, these swollen nodes can turn into abscesses known as buboes.

The CDC recommends treating chancroid with a single oral dose of 1 gram of azithromycin or a single intramuscular dose of ceftriaxone. Alternatively, a 7-day course of oral erythromycin can be used. It’s important to note that Haemophilus ducreyi is resistant to several antibiotics, including penicillins, tetracyclines, trimethoprim, ciprofloxacin, aminoglycosides, and sulfonamides.

Possible complications of chancroid include extensive swelling of the lymph nodes, large abscesses and sinuses in the groin area, phimosis (a condition where the foreskin cannot be retracted), and superinfection with Fusarium spp. or Bacteroides spp.

Syphilis, caused by Treponema pallidum, presents with a painless ulcer called a chancre during its primary stage. This is different from chancroid, which causes painful ulcers. Chlamydia trachomatis can lead to lymphogranuloma venereum, where a painless genital ulcer may develop initially and go unnoticed. Granuloma inguinale, caused by Klebsiella granulomatis, causes painless nodules and ulcers on the genitals that eventually burst and create open, oozing lesions. Neisseria gonorrhoeae, on the other hand, typically causes vaginal or urethral discharge and is often asymptomatic, rather than causing genital ulceration.