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.

Due to the potentially life-threatening nature of the disease, it is crucial to initiate treatment without waiting for laboratory confirmation. Immediate administration of antibiotics is necessary.

In a hospital setting, the preferred agents for treatment are IV ceftriaxone (2 g for adults; 80 mg/kg for children) or IV cefotaxime (2 g for adults; 80 mg/kg for children). In the prehospital setting, IM benzylpenicillin can be given as an alternative. If there is a history of anaphylaxis to cephalosporins, chloramphenicol is a suitable alternative.

It is important to prioritize prompt treatment due to the severity of the disease. The recommended antibiotics should be administered as soon as possible to ensure the best possible outcome for the patient.

Spironolactone is a medication used to treat conditions such as congestive cardiac failure, hypertension, hepatic cirrhosis with ascites and edema, and Conn’s syndrome. It functions as a competitive aldosterone receptor antagonist, primarily working in the distal convoluted tubule. In this area, it hinders the reabsorption of sodium ions and enhances the reabsorption of potassium ions. Spironolactone is commonly known as a potassium-sparing diuretic.

The main side effect of spironolactone is hyperkalemia, particularly when renal impairment is present. In severe cases, hyperkalemia can be life-threatening. Additionally, there is a notable occurrence of gastrointestinal disturbances, with nausea and vomiting being the most common. Women may experience menstrual disturbances, while men may develop gynecomastia, both of which are attributed to the antiandrogenic effects of spironolactone.

The Severity of Alcohol Dependence Questionnaire (SADQ) is a brief, self-administered questionnaire consisting of 20 items. It was developed by the World Health Organisation with the aim of assessing the severity of alcohol dependence. Another assessment tool recommended by NICE is the Leeds Dependence Questionnaire (LDQ), which is a self-completion questionnaire comprising of 10 items. The LDQ is designed to measure dependence on various substances. Both the SADQ and LDQ are considered useful in evaluating the severity of alcohol misuse.

NICE suggests the use of specific assessment tools to effectively evaluate the nature and severity of alcohol misuse. The AUDIT is recommended for identification purposes and as a routine outcome measure. For assessing the severity of dependence, the SADQ or LDQ are recommended. To evaluate the severity of withdrawal symptoms, the Clinical Institute Withdrawal Assessment of Alcohol Scale, revised (CIWA-Ar) is recommended. Lastly, the APQ is recommended for assessing the nature and extent of problems arising from alcohol misuse.

to the NICE guidance on the diagnosis, assessment, and management of harmful drinking and alcohol dependence.

Haemothorax often leads to reduced or absent air entry, a dull percussion sound, and decreased fremitus on the affected side. Commonly observed symptoms in patients with haemothorax include decreased or absent air entry, a dull percussion note when the affected side is tapped, reduced fremitus on the affected side, and in cases of massive haemothorax, tracheal deviation away from the affected side. Other signs that may be present include a rapid heart rate (tachycardia), rapid breathing (tachypnoea), low blood pressure (hypotension), and signs of shock.

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.

Signs that a child with gastroenteritis may be at risk of progressing to shock include altered responsiveness (such as being irritable or lethargic), sunken eyes, a fast heart rate, rapid breathing, and reduced skin elasticity. In infants aged 3 months or younger, a temperature above 38ºC is also a red flag.

Further Reading:

Gastroenteritis is a common condition in children, particularly those under the age of 5. It is characterized by the sudden onset of diarrhea, with or without vomiting. The most common cause of gastroenteritis in infants and young children is rotavirus, although other viruses, bacteria, and parasites can also be responsible. Prior to the introduction of the rotavirus vaccine in 2013, rotavirus was the leading cause of gastroenteritis in children under 5 in the UK. However, the vaccine has led to a significant decrease in cases, with a drop of over 70% in subsequent years.

Norovirus is the most common cause of gastroenteritis in adults, but it also accounts for a significant number of cases in children. In England & Wales, there are approximately 8,000 cases of norovirus each year, with 15-20% of these cases occurring in children under 9.

When assessing a child with gastroenteritis, it is important to consider whether there may be another more serious underlying cause for their symptoms. Dehydration assessment is also crucial, as some children may require intravenous fluids. The NICE traffic light system can be used to identify the risk of serious illness in children under 5.

In terms of investigations, stool microbiological testing may be indicated in certain cases, such as when the patient has been abroad, if diarrhea lasts for more than 7 days, or if there is uncertainty over the diagnosis. U&Es may be necessary if intravenous fluid therapy is required or if there are symptoms and/or signs suggestive of hypernatremia. Blood cultures may be indicated if sepsis is suspected or if antibiotic therapy is planned.

Fluid management is a key aspect of treating children with gastroenteritis. In children without clinical dehydration, normal oral fluid intake should be encouraged, and oral rehydration solution (ORS) supplements may be considered. For children with dehydration, ORS solution is the preferred method of rehydration, unless intravenous fluid therapy is necessary. Intravenous fluids may be required for children with shock or those who are unable to tolerate ORS solution.

Antibiotics are generally not required for gastroenteritis in children, as most cases are viral or self-limiting. However, there are some exceptions, such as suspected or confirmed sepsis, Extraintestinal spread of bacterial infection, or specific infections like Clostridium difficile-associated pseudomembranous enterocolitis or giardiasis.

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. Its mechanism of action involves inhibiting the Na/K ATPase in cardiac myocytes, which leads to an increase in intracellular sodium concentration. This, in turn, indirectly increases the availability of intracellular calcium through Na/Ca exchange.

The rise in intracellular calcium levels caused by digoxin results in a positive inotropic effect, meaning it strengthens the force of heart contractions, and a negative chronotropic effect, meaning it slows down the heart rate.

Therapeutic plasma levels of digoxin typically range between 1.0-1.5 nmol/l. However, higher concentrations may be necessary, and the specific value can vary between different laboratories. It is important to note that the risk of toxicity significantly increases when digoxin levels exceed 2 nmol/l.

Signs and symptoms of digoxin toxicity include nausea, vomiting, diarrhea, abdominal pain, confusion, tachyarrhythmias or bradyarrhythmias, xanthopsia (yellow-green vision), and hyperkalemia (an early sign of significant toxicity).

Several factors can potentially contribute to digoxin toxicity. These include being elderly, having renal failure, experiencing myocardial ischemia, having hypokalemia, hypomagnesemia, hypercalcemia, hypernatremia, acidosis, or hypothyroidism.

Additionally, there are several drugs that can increase the risk of digoxin toxicity. These include spironolactone, amiodarone, quinidine, verapamil, diltiazem, and drugs that cause hypokalemia, such as thiazide and loop diuretics.

Alteplase (rt-pA) is a recommended treatment for acute ischaemic stroke in adults if it is initiated within 4.5 hours of the onset of stroke symptoms. It is crucial to exclude intracranial haemorrhage through appropriate imaging techniques before starting the treatment. The initial dose of alteplase is 0.9 mg/kg, with a maximum of 90 mg. This dose is administered intravenously over a period of 60 minutes. The first 10% of the dose is given through intravenous injection, while the remaining amount is administered through intravenous infusion. For more information, please refer to the NICE guidelines on stroke and transient ischaemic attack in individuals aged 16 and above.

Cushing’s triad is a combination of widened pulse pressure, bradycardia, and reduced respirations. It is a physiological response of the nervous system to acute increases in intracranial pressure (ICP). This response, known as the Cushing reflex, can cause the symptoms of Cushing’s triad. These symptoms include an increase in systolic blood pressure and a decrease in diastolic blood pressure, a slower heart rate, and irregular or reduced breathing. Additionally, raised ICP can also lead to other symptoms such as headache, papilloedema, and vomiting.

Further Reading:

Intracranial pressure (ICP) refers to the pressure within the craniospinal compartment, which includes neural tissue, blood, and cerebrospinal fluid (CSF). Normal ICP for a supine adult is 5-15 mmHg. The body maintains ICP within a narrow range through shifts in CSF production and absorption. If ICP rises, it can lead to decreased cerebral perfusion pressure, resulting in cerebral hypoperfusion, ischemia, and potentially brain herniation.

The cranium, which houses the brain, is a closed rigid box in adults and cannot expand. It is made up of 8 bones and contains three main components: brain tissue, cerebral blood, and CSF. Brain tissue accounts for about 80% of the intracranial volume, while CSF and blood each account for about 10%. The Monro-Kellie doctrine states that the sum of intracranial volumes is constant, so an increase in one component must be offset by a decrease in the others.

There are various causes of raised ICP, including hematomas, neoplasms, brain abscesses, edema, CSF circulation disorders, venous sinus obstruction, and accelerated hypertension. Symptoms of raised ICP include headache, vomiting, pupillary changes, reduced cognition and consciousness, neurological signs, abnormal fundoscopy, cranial nerve palsy, hemiparesis, bradycardia, high blood pressure, irregular breathing, focal neurological deficits, seizures, stupor, coma, and death.

Measuring ICP typically requires invasive procedures, such as inserting a sensor through the skull. Management of raised ICP involves a multi-faceted approach, including antipyretics to maintain normothermia, seizure control, positioning the patient with a 30º head up tilt, maintaining normal blood pressure, providing analgesia, using drugs to lower ICP (such as mannitol or saline), and inducing hypocapnoeic vasoconstriction through hyperventilation. If these measures are ineffective, second-line therapies like barbiturate coma, optimised hyperventilation, controlled hypothermia, or decompressive craniectomy may be considered.

An ectopic pregnancy happens when the fertilized egg attaches itself outside of the uterus. In over 95% of cases, ectopic pregnancies occur in the Fallopian tubes. Although rare, they can also occur in other locations such as the abdomen, cervix, and ovary.

The most common location for an ectopic pregnancy in the Fallopian tube is the ampulla, accounting for approximately 70% of cases. The isthmus and infundibulum each account for 10-15% of cases, while the uterine part only accounts for 2-5%.