Tetralogy of Fallot (TOF) is the most prevalent cause of cyanotic congenital heart disease. It is characterized by four distinct features: pulmonary infundibular stenosis, overriding aorta, ventricular septal defect, and right ventricular hypertrophy. TOF is often associated with various congenital syndromes, including DiGeorge syndrome (22q11 microdeletion syndrome), Trisomy 21, Foetal alcohol syndrome, and Maternal phenylketonuria.

Nowadays, many cases of TOF are identified during antenatal screening or early postnatal assessment due to the presence of a heart murmur. Initially, severe cyanosis is uncommon shortly after birth because the patent ductus arteriosus provides additional blood flow to the lungs. However, once the ductus arteriosus closes, typically a few days after birth, cyanosis can develop.

In cases where TOF goes undetected, the clinical manifestations may include severe cyanosis, poor feeding, breathlessness, dyspnea on exertion (such as prolonged crying), hypercyanotic spells triggered by activity, agitation, developmental delay, and failure to thrive. A cardiac examination may reveal a loud, long ejection systolic murmur caused by pulmonary stenosis, a systolic thrill at the lower left sternal edge, an aortic ejection click, and digital clubbing. Radiologically, a characteristic finding in TOF is a ‘boot-shaped’ heart (Coeur en sabot).

Treatment for TOF often involves two stages. Initially, a palliative procedure is performed to alleviate symptoms, followed by a total repair at a later stage.

When addressing the management of long-term alcohol abuse and promoting self-care, it is important to start by exploring the reasons behind the patient’s previous relapses. This will help understand her beliefs and understanding of her condition and identify any simple, supportive measures that can aid in her efforts to stop drinking.

Referral to the Community Drug and Alcohol Team (CDAT) may be necessary at some point. Depending on the severity and duration of her alcohol abuse, she may be suitable for outpatient or community detox. However, if her drinking has been sustained and heavy for many years, she may require admission for additional support. It is important to note that there is often a long wait for available beds, so it would be more prudent to thoroughly explore her history before making this referral.

While arranging for her liver function to be tested could be part of the general work-up, it is unlikely to be necessary for a leg laceration. It is crucial to avoid suddenly abstaining or prescribing chlordiazepoxide, as these actions can be potentially dangerous. Abrupt detoxification may lead to delirium tremens, which can have catastrophic effects. Chlordiazepoxide may be used under the supervision of experienced professionals, but close monitoring and regular appointments with a GP or specialist are essential.

Digoxin is a medication used to treat atrial fibrillation and flutter as well as congestive cardiac failure. It belongs to a class of drugs called cardiac glycosides. Digoxin works by inhibiting the Na/K ATPase pump in the cardiac myocytes, which are the cells of the heart. This inhibition leads to an increase in the concentration of sodium inside the cells and indirectly increases the availability of calcium through the Na/Ca exchange mechanism. The rise in intracellular calcium levels results in a positive inotropic effect, meaning it strengthens the force of the heart’s contractions, and a negative chronotropic effect, meaning it slows down the heart rate.

However, it’s important to note that digoxin can cause toxicity, which is characterized by high levels of potassium in the blood, known as hyperkalemia. Normally, the Na/K ATPase pump helps maintain the balance of sodium and potassium by allowing sodium to leave the cells and potassium to enter. When digoxin blocks this pump, it disrupts this balance and leads to higher levels of potassium in the bloodstream.

Interestingly, the risk of developing digoxin toxicity is higher in individuals with low levels of potassium, known as hypokalemia. This is because digoxin binds to the ATPase pump at the same site as potassium. When potassium levels are low, digoxin can more easily bind to the ATPase pump and exert its inhibitory effects.

In summary, digoxin is a cardiac glycoside that is used to treat certain heart conditions. It works by inhibiting the Na/K ATPase pump, leading to increased intracellular calcium levels and resulting in a positive inotropic effect and negative chronotropic effect. However, digoxin can also cause toxicity, leading to high levels of potassium in the blood. The risk of toxicity is higher in individuals with low potassium levels.

Orthostatic hypotension is diagnosed using lying and standing blood pressure measurements. This condition is often seen in older individuals who are taking multiple medications for hypertension and depression. The patient exhibits symptoms such as light-headedness, dizziness, weakness, and tunnel vision when standing up. These symptoms do not occur when lying down and worsen upon standing, but can be relieved by sitting or lying down. They are typically more pronounced in the morning, in hot environments, after meals, after standing still, and after exercise. No other signs suggest an alternative diagnosis.

Further Reading:

Blackouts, also known as syncope, are defined as a spontaneous transient loss of consciousness with complete recovery. They are most commonly caused by transient inadequate cerebral blood flow, although epileptic seizures can also result in blackouts. There are several different causes of blackouts, including neurally-mediated reflex syncope (such as vasovagal syncope or fainting), orthostatic hypotension (a drop in blood pressure upon standing), cardiovascular abnormalities, and epilepsy.

When evaluating a patient with blackouts, several key investigations should be performed. These include an electrocardiogram (ECG), heart auscultation, neurological examination, vital signs assessment, lying and standing blood pressure measurements, and blood tests such as a full blood count and glucose level. Additional investigations may be necessary depending on the suspected cause, such as ultrasound or CT scans for aortic dissection or other abdominal and thoracic pathology, chest X-ray for heart failure or pneumothorax, and CT pulmonary angiography for pulmonary embolism.

During the assessment, it is important to screen for red flags and signs of any underlying serious life-threatening condition. Red flags for blackouts include ECG abnormalities, clinical signs of heart failure, a heart murmur, blackouts occurring during exertion, a family history of sudden cardiac death at a young age, an inherited cardiac condition, new or unexplained breathlessness, and blackouts in individuals over the age of 65 without a prodrome. These red flags indicate the need for urgent assessment by an appropriate specialist.

There are several serious conditions that may be suggested by certain features. For example, myocardial infarction or ischemia may be indicated by a history of coronary artery disease, preceding chest pain, and ECG signs such as ST elevation or arrhythmia. Pulmonary embolism may be suggested by dizziness, acute shortness of breath, pleuritic chest pain, and risk factors for venous thromboembolism. Aortic dissection may be indicated by chest and back pain, abnormal ECG findings, and signs of cardiac tamponade include low systolic blood pressure, elevated jugular venous pressure, and muffled heart sounds. Other conditions that may cause blackouts include severe hypoglycemia, Addisonian crisis, and electrolyte abnormalities.

Subclinical hypothyroidism is a condition where the thyroid-stimulating hormone (TSH) levels are higher than normal, but the levels of free thyroxine (T4) are still within the normal range. On the other hand, subclinical hyperthyroidism is a condition where the TSH levels are lower than normal, but the levels of free triiodothyronine (T3) and free thyroxine (T4) are still within the normal range.

Further Reading:

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

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

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

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

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

Pabrinex is a supplement that includes a combination of essential vitamins. These vitamins are Thiamine (also known as vitamin B1), Riboflavin (commonly referred to as vitamin B2), Nicotinamide (which encompasses Vitamin B3, niacin, and nicotinic acid), Pyridoxine (known as vitamin B6), and Ascorbic acid (which is vitamin C). Each of these vitamins plays a crucial role in maintaining our overall health and well-being. By incorporating Pabrinex into our daily routine, we can ensure that our bodies receive the necessary nutrients to support various bodily functions.

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

Further Reading:

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

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

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

presbycusis is a type of hearing loss that occurs gradually as a person ages. It affects both ears and is characterized by a decrease in hearing ability, particularly at higher frequencies. This type of hearing loss worsens over time. When a person has bilateral sensorineural hearing loss, a central Weber’s test and bilaterally diminished Rinne’s tests would be expected.

To perform a Rinne’s test, a 512 Hertz tuning fork is vibrated and placed on the mastoid process until the sound can no longer be heard. Then, the top of the tuning fork is placed 2 centimeters from the external auditory meatus. The patient is asked to indicate where they hear the sound loudest.

In individuals with normal hearing, the tuning fork should still be audible outside the external auditory canal even after it can no longer be heard on the mastoid. This is because air conduction should be better than bone conduction.

In cases of conductive hearing loss, the patient will no longer be able to hear the tuning fork immediately after it can no longer be heard on the mastoid. This indicates that their bone conduction is better than their air conduction, and something is obstructing the passage of sound waves through the ear canal into the cochlea. This is considered a true negative result.

However, a Rinne’s test may produce a false negative result if the patient has a severe unilateral sensorineural deficit and can sense the sound in the unaffected ear through the transmission of sound waves through the base of the skull.

In sensorineural hearing loss, the ability to perceive the tuning fork both on the mastoid and outside the external auditory canal is equally diminished compared to the opposite ear. The sound will still be heard outside the external auditory canal, but it will disappear earlier on the mastoid process and outside the external auditory canal compared to the other ear.

To perform Weber’s test, a 512 Hz tuning fork is vibrated and placed on the center of the patient’s forehead. The patient is then asked if they perceive the sound in the middle of the forehead or if it seems to be more on one side or the other.

If the sound seems to be more on one side, it can indicate either ipsilateral conductive hearing loss or contralateral sensorineural hearing loss.

The cardiotoxic effects of TCAs occur when they block sodium channels, leading to broadening of the QRS complex, and potassium channels, resulting in prolongation of the QT interval. The severity of adverse events is directly related to the degree of QRS broadening. If the QRS complex is greater than 100 ms, it is likely that seizures may occur. If the QRS complex exceeds 160 ms, ventricular arrhythmias may be predicted. In cases of TCA overdose, certain changes can be observed on an ECG. These include sinus tachycardia, which is very common, prolongation of the PR interval, broadening of the QRS complex, prolongation of the QT interval, and in severe cases, ventricular arrhythmias.

The use of NSAIDs during the third trimester of pregnancy is associated with several risks. These risks include delayed onset of labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus, which is a condition characterized by bilirubin-induced brain dysfunction. Additionally, there is a slight increase in the risk of first-trimester abortion if NSAIDs are used early in pregnancy.

Below is a list outlining the most 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, leading to deafness in the fetus.

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.

Drug: Benzodiazepines (e.g. diazepam)
Adverse effects: When given late in pregnancy, benzodiazepines can cause respiratory depression and a neonatal withdrawal syndrome.

Drug: Calcium-channel blockers
Adverse effects: If given in the first trimester, calcium-channel blockers can cause phalangeal abnormalities. If given in the second and third trimester, they can cause fetal growth retardation.

Activated charcoal is a commonly used substance for decontamination in cases of poisoning. Its main function is to adsorb the molecules of the ingested toxin onto its surface.

Activated charcoal is a chemically inert form of carbon. It is a fine black powder that has no odor or taste. It is produced by subjecting carbonaceous matter to high temperatures, a process known as pyrolysis, and then concentrating it with a zinc chloride solution. This creates a network of pores within the charcoal, giving it a large absorptive area of approximately 3,000 m2/g. This porous structure helps prevent the absorption of the harmful toxin by up to 50%.

The usual dosage of activated charcoal is 50 grams for adults and 1 gram per kilogram of body weight for children. It can be administered orally or through a nasogastric tube. It is important to give the charcoal within one hour of ingestion, and it may be repeated after one hour if necessary.

However, there are certain situations where activated charcoal should not be used. If the patient is unconscious or in a coma, there is a risk of aspiration, so the charcoal should not be given. Similarly, if seizures are likely to occur, there is a risk of aspiration and the charcoal should be avoided. Additionally, if there is reduced gastrointestinal motility, there is a risk of obstruction, so activated charcoal should not be used in such cases.

Activated charcoal is effective in treating overdose with various drugs and toxins, including aspirin, paracetamol, barbiturates, tricyclic antidepressants, digoxin, amphetamines, morphine, cocaine, and phenothiazines. However, it is ineffective in treating overdose with substances such as iron, lithium, boric acid, cyanide, ethanol, ethylene glycol, methanol, malathion, DDT, carbamate, hydrocarbon, strong acids, or alkalis.

There are some potential adverse effects associated with activated charcoal. These include nausea and vomiting, diarrhea, constipation, bezoar formation (a mass of undigested material that can cause blockages), bowel obstruction, pulmonary aspiration (inhaling the charcoal into the lungs), and impaired absorption of oral medications or antidotes.

An acoustic neuroma, also referred to as a vestibular schwannoma, is a slow-growing tumor that develops from the Schwann cells of the vestibulocochlear nerve (8th cranial nerve). These growths are typically found at the cerebellopontine angle or within the internal auditory canal.

The most commonly affected nerves are the vestibulocochlear and trigeminal nerves. Patients typically experience a gradual deterioration of hearing in one ear, along with numbness and tingling in the face, ringing in the ears, and episodes of dizziness. Headaches may also be present, and in rare cases, the facial nerve, glossopharyngeal nerve, vagus nerve, or accessory nerve may be affected.

It’s important to note that the trochlear nerve, which passes through the superior orbital fissure, is not impacted by an acoustic neuroma.

In a patient with severe otitis externa on the left side, it is expected that they will experience conductive deafness on the left side. This means that their ability to hear sound will be impaired due to a problem in the ear canal or middle ear. When conducting a Rinne’s test, a vibrating 512 Hz tuning fork is placed on the mastoid process until the patient can no longer hear the sound. Then, the top of the tuning fork is positioned 2 cm from the external auditory meatus, and the patient is asked where they hear the sound loudest.

In individuals with normal hearing, the sound from the tuning fork should still be audible outside the external auditory canal even after it can no longer be heard on the mastoid. This is because air conduction should be better than bone conduction. However, in cases of conductive hearing loss, the patient will no longer be able to hear the tuning fork once it is removed from the mastoid. This indicates that their bone conduction is greater than their air conduction, suggesting an obstruction in the ear canal that prevents sound waves from reaching the cochlea. This is referred to as a true negative result.

It is important to note that a Rinne’s test may yield a false negative result if the patient has a severe unilateral sensorineural deficit. In this case, they may still sense the sound in the unaffected ear due to the transmission of sound through the base of the skull. In contrast, individuals with sensorineural hearing loss will have diminished ability to hear the tuning fork both on the mastoid and outside the external auditory canal compared to the opposite ear. The sound will disappear earlier on the mastoid and outside the external auditory canal in the affected ear.

When performing Weber’s test, a vibrating 512 Hz tuning fork is placed on the center of the patient’s forehead. The patient is then asked if they perceive the sound in the middle of the forehead or if it lateralizes to one side. If the sound lateralizes to one side, it can indicate either ipsilateral conductive hearing loss or contralateral sensorineural hearing loss.

This patient is displaying symptoms and signs that are in line with community-acquired pneumonia (CAP). The most frequent cause of CAP in an adult patient who is otherwise in good health is Streptococcus pneumoniae.

Patients who are on beta-blockers may not respond effectively to adrenaline during anaphylaxis. Research conducted on animals and reported cases have indicated that glucagon can be utilized to counteract the effects of beta-blockade if initial adrenaline doses prove ineffective.

Although prednisolone and hydrocortisone can be beneficial later on, it typically takes 6-8 hours for them to take full effect. Therefore, they are unlikely to have any impact on the patient during the brief period it will take for the ambulance to arrive.

Pericarditis refers to the inflammation of the pericardium, which can be caused by various factors such as infections (typically viral, like coxsackie virus), drug-induced reactions (e.g. isoniazid, cyclosporine), trauma, autoimmune conditions (e.g. SLE), paraneoplastic syndromes, uremia, post myocardial infarction (known as Dressler’s syndrome), post radiotherapy, and post cardiac surgery.

The clinical presentation of pericarditis often includes retrosternal chest pain that worsens with lying flat and improves when sitting forwards, along with shortness of breath, rapid heartbeat, and the presence of a pericardial friction rub.

Characteristic electrocardiogram (ECG) changes associated with pericarditis typically show widespread concave or ‘saddle-shaped’ ST elevation, widespread PR depression, reciprocal ST depression and PR elevation in aVR (and sometimes V1), and sinus tachycardia is commonly observed.

The risk of primary spontaneous pneumothorax is associated with smoking tobacco and increases as the duration of exposure and daily consumption rise. The changes caused by smoking in the small airways may contribute to the development of local emphysema, leading to the formation of bullae. In this case, the patient does not have any clinical features or significant risk factors for the other conditions mentioned. Therefore, primary spontaneous pneumothorax is the most probable diagnosis.

The plasma osmolality for this patient can be calculated by multiplying the sodium concentration by 2, adding the glucose concentration, and then adding the urea concentration. In this case, the calculation would be (2 x 146) + 38 + 21.

Further Reading:

Hyperosmolar hyperglycaemic state (HHS) is a syndrome that occurs in people with type 2 diabetes and is characterized by extremely high blood glucose levels, dehydration, and hyperosmolarity without significant ketosis. It can develop over days or weeks and has a mortality rate of 5-20%, which is higher than that of diabetic ketoacidosis (DKA). HHS is often precipitated by factors such as infection, inadequate diabetic treatment, physiological stress, or certain medications.

Clinical features of HHS include polyuria, polydipsia, nausea, signs of dehydration (hypotension, tachycardia, poor skin turgor), lethargy, confusion, and weakness. Initial investigations for HHS include measuring capillary blood glucose, venous blood gas, urinalysis, and an ECG to assess for any potential complications such as myocardial infarction. Osmolality should also be calculated to monitor the severity of the condition.

The management of HHS aims to correct dehydration, hyperglycaemia, hyperosmolarity, and electrolyte disturbances, as well as identify and treat any underlying causes. Intravenous 0.9% sodium chloride solution is the principal fluid used to restore circulating volume and reverse dehydration. If the osmolality does not decline despite adequate fluid balance, a switch to 0.45% sodium chloride solution may be considered. Care must be taken in correcting plasma sodium and osmolality to avoid complications such as cerebral edema and osmotic demyelination syndrome.

The rate of fall of plasma sodium should not exceed 10 mmol/L in 24 hours, and the fall in blood glucose should be no more than 5 mmol/L per hour. Low-dose intravenous insulin may be initiated if the blood glucose is not falling with fluids alone or if there is significant ketonaemia. Potassium replacement should be guided by the potassium level, and the patient should be encouraged to drink as soon as it is safe to do so.

Complications of treatment, such as fluid overload, cerebral edema, or central pontine myelinolysis, should be assessed for, and underlying precipitating factors should be identified and treated. Prophylactic anticoagulation is required in most patients, and all patients should be assumed to be at high risk of foot ulceration, necessitating appropriate foot protection and daily foot checks.

The primary symptom typically associated with carbon monoxide poisoning is a headache.

Carbon monoxide (CO) is a dangerous gas that is produced by the combustion of hydrocarbon fuels and can be found in certain chemicals. It is colorless and odorless, making it difficult to detect. In England and Wales, there are approximately 60 deaths each year due to accidental CO poisoning.

When inhaled, carbon monoxide binds to haemoglobin in the blood, forming carboxyhaemoglobin (COHb). It has a higher affinity for haemoglobin than oxygen, causing a left-shift in the oxygen dissociation curve and resulting in tissue hypoxia. This means that even though there may be a normal level of oxygen in the blood, it is less readily released to the tissues.

The clinical features of carbon monoxide toxicity can vary depending on the severity of the poisoning. Mild or chronic poisoning may present with symptoms such as headache, nausea, vomiting, vertigo, confusion, and weakness. More severe poisoning can lead to intoxication, personality changes, breathlessness, pink skin and mucosae, hyperpyrexia, arrhythmias, seizures, blurred vision or blindness, deafness, extrapyramidal features, coma, or even death.

To help diagnose domestic carbon monoxide poisoning, there are four key questions that can be asked using the COMA acronym. These questions include asking about co-habitees and co-occupants in the house, whether symptoms improve outside of the house, the maintenance of boilers and cooking appliances, and the presence of a functioning CO alarm.

Typical carboxyhaemoglobin levels can vary depending on whether the individual is a smoker or non-smoker. Non-smokers typically have levels below 3%, while smokers may have levels below 10%. Symptomatic individuals usually have levels between 10-30%, and severe toxicity is indicated by levels above 30%.

When managing carbon monoxide poisoning, the first step is to administer 100% oxygen. Hyperbaric oxygen therapy may be considered for individuals with a COHb concentration of over 20% and additional risk factors such as loss of consciousness, neurological signs, myocardial ischemia or arrhythmia, or pregnancy. Other management strategies may include fluid resuscitation, sodium bicarbonate for metabolic acidosis, and mannitol for cerebral edema.

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

Further Reading:

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

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

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

Shock is a condition characterized by inadequate tissue perfusion due to circulatory insufficiency. It can be caused by fluid loss or redistribution, as well as impaired cardiac output. The main causes of shock include haemorrhage, diarrhoea and vomiting, burns, diuresis, sepsis, neurogenic shock, anaphylaxis, massive pulmonary embolism, tension pneumothorax, cardiac tamponade, myocardial infarction, and myocarditis.

One common cause of shock is haemorrhage, which is frequently encountered in the emergency department. Haemorrhagic shock can be classified into different types based on the amount of blood loss. Type 1 haemorrhagic shock involves a blood loss of 15% or less, with less than 750 ml of blood loss. Patients with type 1 shock may have normal blood pressure and heart rate, with a respiratory rate of 12 to 20 breaths per minute.

Type 2 haemorrhagic shock involves a blood loss of 15 to 30%, with 750 to 1500 ml of blood loss. Patients with type 2 shock may have a pulse rate of 100 to 120 beats per minute and a respiratory rate of 20 to 30 breaths per minute. Blood pressure is typically normal in type 2 shock.

Type 3 haemorrhagic shock involves a blood loss of 30 to 40%, with 1.5 to 2 litres of blood loss. Patients with type 3 shock may have a pulse rate of 120 to 140 beats per minute and a respiratory rate of more than 30 breaths per minute. Urine output is decreased to 5-15 mls per hour.

Type 4 haemorrhagic shock involves a blood loss of more than 40%, with more than 2 litres of blood loss. Patients with type 4 shock may have a pulse rate of more than 140 beats per minute and a respiratory rate of more than 35 breaths per minute. They may also be drowsy, confused, and possibly experience loss of consciousness. Urine output may be minimal or absent.

In summary, shock is a condition characterized by inadequate tissue perfusion. Haemorrhage is a common cause of shock, and it can be classified into different types based on the amount of blood loss. Prompt recognition and management of shock are crucial in order to prevent further complications and improve patient outcomes

The FeverPAIN score is a clinical scoring system that helps determine the likelihood of a streptococcal infection and whether antibiotic treatment is necessary. It consists of several criteria that are assessed to assign a score.

Firstly, if the patient has a fever higher than 38°C, they score 0 or 1 depending on the presence or absence of this symptom.

Secondly, the presence of purulence, such as pharyngeal or tonsillar exudate, results in a score of 1.

Thirdly, if the patient sought medical attention within 3 days or less, they score 1.

Fourthly, if the patient has severely inflamed tonsils, they score 1.

Lastly, if the patient does not have a cough or coryza (nasal congestion), they score 1.

By adding up the scores from each criterion, the FeverPAIN score can help healthcare professionals determine the likelihood of a streptococcal infection and guide the decision on whether antibiotic treatment is necessary. In this particular case, the patient has a score of 4.

Further Reading:

Pharyngitis and tonsillitis are common conditions that cause inflammation in the throat. Pharyngitis refers to inflammation of the oropharynx, which is located behind the soft palate, while tonsillitis refers to inflammation of the tonsils. These conditions can be caused by a variety of pathogens, including viruses and bacteria. The most common viral causes include rhinovirus, coronavirus, parainfluenza virus, influenza types A and B, adenovirus, herpes simplex virus type 1, and Epstein Barr virus. The most common bacterial cause is Streptococcus pyogenes, also known as Group A beta-hemolytic streptococcus (GABHS). Other bacterial causes include Group C and G beta-hemolytic streptococci and Fusobacterium necrophorum.

Group A beta-hemolytic streptococcus is the most concerning pathogen as it can lead to serious complications such as rheumatic fever and glomerulonephritis. These complications can occur due to an autoimmune reaction triggered by antigen/antibody complex formation or from cell damage caused by bacterial exotoxins.

When assessing a patient with a sore throat, the clinician should inquire about the duration and severity of the illness, as well as associated symptoms such as fever, malaise, headache, and joint pain. It is important to identify any red flags and determine if the patient is immunocompromised. Previous non-suppurative complications of Group A beta-hemolytic streptococcus infection should also be considered, as there is an increased risk of further complications with subsequent infections.

Red flags that may indicate a more serious condition include severe pain, neck stiffness, or difficulty swallowing. These symptoms may suggest epiglottitis or a retropharyngeal abscess, which require immediate attention.

To determine the likelihood of a streptococcal infection and the need for antibiotic treatment, two scoring systems can be used: CENTOR and FeverPAIN. The CENTOR criteria include tonsillar exudate, tender anterior cervical lymphadenopathy or lymphadenitis, history of fever, and absence of cough. The FeverPAIN criteria include fever, purulence, rapid onset of symptoms, severely inflamed tonsils, and absence of cough or coryza. Based on the scores from these criteria, the likelihood of a streptococcal infection can be estimated, and appropriate management can be undertaken. can

Patients with Parkinson’s disease (PD) typically exhibit the following clinical features:

– Hypokinesia (reduced movement)
– Bradykinesia (slow movement)
– Rest tremor (usually occurring at a rate of 4-6 cycles per second)
– Rigidity (increased muscle tone and ‘cogwheel rigidity’)

Other commonly observed clinical features include:

– Gait disturbance (characterized by a shuffling gait and loss of arm swing)
– Loss of facial expression
– Monotonous, slurred speech
– Micrographia (small, cramped handwriting)
– Increased salivation and dribbling
– Difficulty with fine movements

Initially, these signs are typically seen on one side of the body at the time of diagnosis, but they progressively worsen and may eventually affect both sides. In later stages of the disease, additional clinical features may become evident, including:

– Postural instability
– Cognitive impairment
– Orthostatic hypotension

Although PD primarily affects movement, patients often experience psychiatric issues such as depression and dementia. Autonomic disturbances and pain can also occur, leading to significant disability and reduced quality of life for the affected individual. Additionally, family members and caregivers may also be indirectly affected by the disease.

Recurrent or chronic tonsillitis is a clear indication for tonsillectomy, which is the surgical removal of the palatine tonsils. One common complication of this procedure is bleeding, which occurs in approximately 0.5-2% of cases. The bleeding that occurs after tonsillectomy is typically venous in nature and most frequently originates from the external palatine vein. This vein drains the lateral tonsillar region and ultimately empties into the facial vein. Additionally, bleeding can also arise from the tonsillar branch of the facial artery, which supplies the inferior pole of the palatine tonsil.

According to the current guidelines from NICE, alteplase is recommended as a thrombolysis treatment for acute ischaemic stroke. For more information, you can refer to the NICE guidelines on stroke and transient ischaemic attack in individuals over the age of 16.

It is unlikely that this patient has glandular fever, as school exclusion is not necessary for this condition. However, it is important to note that in the UK, school exclusion is not required for tonsillitis either. The only exception is if a child has tonsillitis and a rash consistent with scarlet fever, in which case exclusion is necessary for 24 hours after starting antibiotics. The child and parents should be provided with additional information about glandular fever (refer to the notes below).

Further Reading:

Glandular fever, also known as infectious mononucleosis or mono, is a clinical syndrome characterized by symptoms such as sore throat, fever, and swollen lymph nodes. It is primarily caused by the Epstein-Barr virus (EBV), with other viruses and infections accounting for the remaining cases. Glandular fever is transmitted through infected saliva and primarily affects adolescents and young adults. The incubation period is 4-8 weeks.

The majority of EBV infections are asymptomatic, with over 95% of adults worldwide having evidence of prior infection. Clinical features of glandular fever include fever, sore throat, exudative tonsillitis, lymphadenopathy, and prodromal symptoms such as fatigue and headache. Splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver) may also be present, and a non-pruritic macular rash can sometimes occur.

Glandular fever can lead to complications such as splenic rupture, which increases the risk of rupture in the spleen. Approximately 50% of splenic ruptures associated with glandular fever are spontaneous, while the other 50% follow trauma. Diagnosis of glandular fever involves various investigations, including viral serology for EBV, monospot test, and liver function tests. Additional serology tests may be conducted if EBV testing is negative.

Management of glandular fever involves supportive care and symptomatic relief with simple analgesia. Antiviral medication has not been shown to be beneficial. It is important to identify patients at risk of serious complications, such as airway obstruction, splenic rupture, and dehydration, and provide appropriate management. Patients can be advised to return to normal activities as soon as possible, avoiding heavy lifting and contact sports for the first month to reduce the risk of splenic rupture.

Rare but serious complications associated with glandular fever include hepatitis, upper airway obstruction, cardiac complications, renal complications, neurological complications, haematological complications, chronic fatigue, and an increased risk of lymphoproliferative cancers and multiple sclerosis.

The mast cell tryptase test, also known as the tryptase test, is a valuable tool for detecting mast cell activation and confirming the diagnosis of anaphylaxis in cases where there is uncertainty. Tryptase is the primary protein found in mast cells. During anaphylaxis, mast cells release their contents, leading to an increase in blood tryptase levels. Typically, these levels start to rise approximately 30 minutes after symptoms begin, reach their peak at 1-2 hours, and return to normal within 6-8 hours.

For optimal results, it is recommended to collect three timed samples. The first sample should be taken as soon as possible after resuscitation efforts have commenced. The second sample should be obtained 1-2 hours after the onset of symptoms. Lastly, a third sample should be collected at the 24-hour mark to establish a baseline level.

While skin allergy tests, like the patch test, and blood tests for specific IgE can help identify the trigger of an allergic reaction, they alone cannot confirm the occurrence of anaphylaxis. The mast cell tryptase test, on the other hand, provides valuable information in confirming the diagnosis.

This patient has developed Wernicke’s encephalopathy, a condition that is associated with alcohol abuse and other causes of thiamine deficiency. It is important to note that the infusion of glucose-containing intravenous fluids without thiamine in a patient with chronic thiamine deficiency can trigger Wernicke’s encephalopathy. In this particular case, it seems that this is what has occurred.

Wernicke’s encephalopathy is typically characterized by a triad of symptoms, which include acute confusion, ophthalmoplegia, and ataxia. Additionally, other possible features of this condition may include papilloedema, hearing loss, apathy, dysphagia, memory impairment, and hypothermia. It is also common for peripheral neuropathy, primarily affecting the legs, to occur in the majority of cases.

This condition is characterized by the presence of acute capillary haemorrhages, astrocytosis, and neuronal death in the upper brainstem and diencephalon. These abnormalities can be visualized through MRI scanning, although CT scanning is not very useful for diagnosis.

If left untreated, most patients with Wernicke’s encephalopathy will go on to develop a Korsakoff psychosis. This condition is characterized by retrograde amnesia, an inability to form new memories, disordered time perception, and confabulation.

Patients who are suspected to have Wernicke’s encephalopathy should be promptly treated with parenteral thiamine (such as Pabrinex) for a minimum of 5 days. Following the parenteral therapy, oral thiamine should be administered.

Phenytoin is widely known for its ability to cause gum hypertrophy. This condition is believed to occur as a result of decreased folate levels, but studies have shown that taking folic acid supplements can help prevent it. In addition to gum hypertrophy, other side effects that may occur with phenytoin use include megaloblastic anemia, nystagmus, ataxia, hypertrichosis, pruritic rash, hirsutism, and drug-induced lupus.

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