The recommended dose of etomidate for rapid sequence intubation (RSI) is typically 0.3mg per kilogram of body weight. For example, a patient weighing 70 kilograms would receive a dose of 21mg (70 x 0.3 = 21mg). This dosage falls within the accepted range of 0.15-0.3 mg/kg as suggested by the British National Formulary (BNF). Therefore, the only option within this range is the fourth option.

Further Reading:

There are four commonly used induction agents in the UK: propofol, ketamine, thiopentone, and etomidate.

Propofol is a 1% solution that produces significant venodilation and myocardial depression. It can also reduce cerebral perfusion pressure. The typical dose for propofol is 1.5-2.5 mg/kg. However, it can cause side effects such as hypotension, respiratory depression, and pain at the site of injection.

Ketamine is another induction agent that produces a dissociative state. It does not display a dose-response continuum, meaning that the effects do not necessarily increase with higher doses. Ketamine can cause bronchodilation, which is useful in patients with asthma. The initial dose for ketamine is 0.5-2 mg/kg, with a typical IV dose of 1.5 mg/kg. Side effects of ketamine include tachycardia, hypertension, laryngospasm, unpleasant hallucinations, nausea and vomiting, hypersalivation, increased intracranial and intraocular pressure, nystagmus and diplopia, abnormal movements, and skin reactions.

Thiopentone is an ultra-short acting barbiturate that acts on the GABA receptor complex. It decreases cerebral metabolic oxygen and reduces cerebral blood flow and intracranial pressure. The adult dose for thiopentone is 3-5 mg/kg, while the child dose is 5-8 mg/kg. However, these doses should be halved in patients with hypovolemia. Side effects of thiopentone include venodilation, myocardial depression, and hypotension. It is contraindicated in patients with acute porphyrias and myotonic dystrophy.

Etomidate is the most haemodynamically stable induction agent and is useful in patients with hypovolemia, anaphylaxis, and asthma. It has similar cerebral effects to thiopentone. The dose for etomidate is 0.15-0.3 mg/kg. Side effects of etomidate include injection site pain, movement disorders, adrenal insufficiency, and apnoea. It is contraindicated in patients with sepsis due to adrenal suppression.

Wolff-Parkinson-White (WPW) syndrome is a condition that affects the electrical system of the heart. It occurs when there is an abnormal pathway, known as the bundle of Kent, between the atria and the ventricles. This pathway can cause premature contractions of the ventricles, leading to a type of rapid heartbeat called atrioventricular re-entrant tachycardia (AVRT).

In a normal heart rhythm, the electrical signals travel through the bundle of Kent and stimulate the ventricles. However, in WPW syndrome, these signals can cause the ventricles to contract prematurely. This can be seen on an electrocardiogram (ECG) as a shortened PR interval, a slurring of the initial rise in the QRS complex (known as a delta wave), and a widening of the QRS complex.

There are two distinct types of WPW syndrome that can be identified on an ECG. Type A is characterized by predominantly positive delta waves and QRS complexes in the praecordial leads, with a dominant R wave in V1. This can sometimes be mistaken for right bundle branch block (RBBB). Type B, on the other hand, shows predominantly negative delta waves and QRS complexes in leads V1 and V2, and positive in the other praecordial leads, resembling left bundle branch block (LBBB).

Overall, WPW syndrome is a condition that affects the electrical conduction system of the heart, leading to abnormal heart rhythms. It can be identified on an ECG by specific features such as shortened PR interval, delta waves, and widened QRS complex.

When patients have calcaneal fractures, it is important to evaluate them for any additional injuries that may be present. These can include vertebral fractures, fractures in the opposite calcaneus, and injuries to the cuboid bone.

Further Reading:

Calcaneus fractures are a common type of lower limb and joint injury. The calcaneus, or heel bone, is the most frequently fractured tarsal bone. These fractures are often intra-articular, meaning they involve the joint. The most common cause of calcaneus fractures is a fall or jump from a height.

When assessing calcaneus fractures, X-rays are used to visualize the fracture lines. Two angles are commonly assessed to determine the severity of the fracture. Böhler’s angle, which measures the angle between two tangent lines drawn across the anterior and posterior borders of the calcaneus, should be between 20-40 degrees. If it is less than 20 degrees, it indicates a calcaneal fracture with flattening. The angle of Gissane, which measures the depression of the posterior facet of the subtalar joint, should be between 120-145 degrees. An increased angle of Gissane suggests a calcaneal fracture.

In the emergency department, the management of a fractured calcaneus involves identifying the injury and any associated injuries, providing pain relief, elevating the affected limb(s), and referring the patient to an orthopedic specialist. It is important to be aware that calcaneus fractures are often accompanied by other injuries, such as bilateral fractures of vertebral fractures.

The definitive management of a fractured calcaneus can be done conservatively or through surgery, specifically open reduction internal fixation (ORIF). The orthopedic team will typically order a CT or MRI scan to classify the fracture and determine the most appropriate treatment. However, a recent UK heel fracture trial suggests that in most cases, ORIF does not improve fracture outcomes.

The clinical symptoms of mitral stenosis include shortness of breath, which tends to worsen during exercise and when lying flat. Tiredness, palpitations, ankle swelling, cough, and haemoptysis are also common symptoms. Chest discomfort is rarely reported.

The clinical signs of mitral stenosis can include a malar flush, an irregular pulse if atrial fibrillation is present, a tapping apex beat that can be felt as the first heart sound, and a left parasternal heave if there is pulmonary hypertension. The first heart sound is often loud, and a mid-diastolic murmur can be heard.

The mid-diastolic murmur of mitral stenosis is a rumbling sound that is best heard at the apex, in the left lateral position during expiration, using the bell of the stethoscope.

Mitral stenosis is typically caused by rheumatic heart disease, and it is more common in females, with about two-thirds of patients being female.

Adenosine is a type of purine nucleoside that is primarily utilized in the diagnosis and treatment of paroxysmal supraventricular tachycardia. Its main mechanism of action involves stimulating A1-adenosine receptors and opening acetylcholine-sensitive potassium channels. This leads to hyperpolarization of the cell membrane in the atrioventricular (AV) node and slows down conduction in the AV node by inhibiting calcium channels.

When administering adenosine, it is given rapidly through an intravenous bolus, followed by a saline flush. The initial dose for adults is 6 mg, and if necessary, additional doses of 12 mg or 18 mg can be given at 1-2 minute intervals until the desired effect is observed. It is important to note that the latest ALS guidelines recommend 18 mg for the third dose, while the BNF/NICE guidelines suggest 12 mg.

One of the advantages of adenosine is its very short half-life, which is less than 10 seconds. This means that its effects are rapid, typically occurring within 10 seconds. However, the duration of action is also short, lasting only 10-20 seconds. Due to its short half-life, any side effects experienced are usually brief. These side effects may include a sense of impending doom, facial flushing, dyspnea, chest discomfort, and a metallic taste.

There are certain contraindications to the use of adenosine. These include 2nd or 3rd degree AV block, sick sinus syndrome, long QT syndrome, severe hypotension, decompensated heart failure, chronic obstructive lung disease, and asthma. It is important to exercise caution when administering adenosine to patients with a heart transplant, as they are particularly sensitive to its effects. In these cases, a reduced initial dose of 3 mg is recommended, followed by 6 mg and then 12 mg.

It is worth noting that the effects of adenosine can be potentiated by dipyridamole, a medication commonly used in combination with adenosine. Therefore, the dose of adenosine should be adjusted and reduced in patients who are also taking dipyridamole.

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

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

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

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

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

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

To distinguish

Nelson’s syndrome is a rare condition that occurs many years after a bilateral adrenalectomy for Cushing’s syndrome. It is believed to develop due to the loss of the normal negative feedback control that suppresses high cortisol levels. As a result, the hypothalamus starts producing CRH again, which stimulates the growth of a pituitary adenoma that produces adrenocorticotropic hormone (ACTH).

Only 15-20% of patients who undergo bilateral adrenalectomy will develop this condition, and it is now rarely seen as the procedure is no longer commonly performed.

The symptoms and signs of Nelson’s syndrome are related to the growth of the pituitary adenoma and the increased production of ACTH and melanocyte-stimulating hormone (MSH) from the adenoma. These may include headaches, visual field defects (up to 50% of cases), increased skin pigmentation, and the possibility of hypopituitarism.

ACTH levels will be significantly elevated (usually >500 ng/L). Thyroxine, TSH, gonadotrophin, and sex hormone levels may be low. Prolactin levels may be high, but not as high as with a prolactin-producing tumor. MRI or CT scanning can be helpful in identifying the presence of an expanding pituitary mass.

The treatment of choice for Nelson’s syndrome is trans-sphenoidal surgery.

Conservative management of ureteric stones may involve the use of medical expulsive therapy (MET), which can be achieved through the administration of either an alpha-blocker or a calcium-channel blocker. This treatment aims to facilitate the natural passage of the stone during the observation period.

Research has shown that in adults, both alpha-blockers and calcium channel blockers have been effective in improving the passage of distal ureteric stones that are less than 10 mm in size, when compared to no treatment. Additionally, alpha-blockers have shown to be more effective than placebo in promoting stone passage. Alpha-blockers have also demonstrated more benefits than calcium channel blockers in terms of stone passage, as well as some advantages in terms of hospital stay and pain management. However, there was no significant difference in the time it took for the stone to pass or the overall quality of life.

Currently, the National Institute for Health and Care Excellence (NICE) recommends alpha-blockers as the preferred choice for medical expulsive therapy. For more detailed information, you can refer to the NICE guidelines on the assessment and management of renal and ureteric stones.

Blood transfusion is a crucial 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.

Delayed haemolytic transfusion reactions (DHTRs) typically occur 4-8 days after a blood transfusion, but can sometimes manifest up to a month later. The symptoms are similar to acute haemolytic transfusion reactions but are usually less severe. Patients may experience fever, inadequate rise in haemoglobin, jaundice, reticulocytosis, positive antibody screen, and positive Direct Antiglobulin Test (Coombs test). DHTRs are more common in patients with sickle cell disease who have received frequent transfusions.

These reactions are caused by the presence of a low titre antibody that is too weak to be detected during cross-match and unable to cause lysis at the time of transfusion. The severity of DHTRs depends on the immunogenicity or dose of the antigen. Blood group antibodies associated with DHTRs include those of the Kidd, Duffy, Kell, and MNS systems. Most DHTRs have a benign course and do not require treatment. However, severe haemolysis with anaemia and renal failure can occur, so monitoring of haemoglobin levels and renal function is necessary. If an antibody is detected, antigen-negative blood can be requested for future transfusions.

Here is a summary of the main transfusion reactions and complications:

1. Febrile transfusion reaction: Presents with a 1-degree rise in temperature from baseline, along with chills and malaise. It is the most common reaction and is usually caused by cytokines from leukocytes in transfused red cell or platelet components. Supportive treatment with paracetamol is helpful.

2. Acute haemolytic reaction: Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine. It is the most serious type of reaction and often occurs due to ABO incompatibility from administration errors. The transfusion should be stopped, and IV fluids should be administered. Diuretics may be required.

3. Delayed haemolytic reaction: This reaction typically occurs 4-8 days after a blood transfusion and presents with fever, anaemia, jaundice and haemoglobuinuria. Direct antiglobulin (Coombs) test positive. Due to low titre antibody too weak to detect in cross-match and unable to cause lysis at time of transfusion. Most delayed haemolytic reactions have a benign course and require no treatment. Monitor anaemia and renal function and treat as required.

Ascending cholangitis occurs when there is an infection in the common bile duct, often caused by a stone that has led to a blockage of bile flow. This condition is characterized by the presence of Charcot’s triad, which includes jaundice, fever with rigors, and pain in the right upper quadrant of the abdomen. It is a serious medical emergency that can be life-threatening, with some patients also experiencing altered mental status and low blood pressure due to septic shock, known as Reynold’s pentad. Urgent biliary drainage is the recommended treatment for ascending cholangitis.

In acute cholecystitis, Murphy’s sign is typically positive, indicating tenderness in the right upper quadrant when the gallbladder is palpated. However, it is negative in cases of biliary colic and ascending cholangitis. The white cell count and C-reactive protein (CRP) levels are usually elevated in ascending cholangitis, along with the presence of jaundice and significantly increased levels of alkaline phosphatase (ALP) and bilirubin.

To differentiate between biliary colic, acute cholecystitis, and ascending cholangitis, the following 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
– Bilirubin: Elevated