Wernicke’s encephalopathy is a condition that is commonly associated with alcohol abuse and other causes of thiamine deficiency. It is characterized by a classic triad of symptoms, including acute confusion, ophthalmoplegia (paralysis or weakness of the eye muscles), and ataxia (loss of coordination). Additional possible features of this condition may include papilloedema (swelling of the optic disc), hearing loss, apathy, dysphagia (difficulty swallowing), memory impairment, and hypothermia. The majority of cases also experience peripheral neuropathy, which typically affects the legs.

The condition is marked by acute capillary haemorrhages, astrocytosis (increase in the number of astrocytes, a type of brain cell), and neuronal death in the upper brainstem and diencephalon. These abnormalities can be visualized using MRI scanning, while 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 (loss of memory for events that occurred before the onset of amnesia), an inability to form new memories, disordered time perception, and confabulation (fabrication of false memories).

When Wernicke’s encephalopathy is suspected, it is crucial to administer parenteral thiamine (such as Pabrinex) for at least 5 days. Following the parenteral therapy, oral thiamine should be continued.

The earliest and most frequent clinical indication of malignant hyperthermia is typically an increase in end tidal CO2. An unexplained elevation in end tidal CO2 is often the initial and most reliable sign of this condition.

Further Reading:

Malignant hyperthermia is a rare and life-threatening syndrome that can be triggered by certain medications in individuals who are genetically susceptible. The most common triggers are suxamethonium and inhalational anaesthetic agents. The syndrome is caused by the release of stored calcium ions from skeletal muscle cells, leading to uncontrolled muscle contraction and excessive heat production. This results in symptoms such as high fever, sweating, flushed skin, rapid heartbeat, and muscle rigidity. It can also lead to complications such as acute kidney injury, rhabdomyolysis, and metabolic acidosis. Treatment involves discontinuing the trigger medication, administering dantrolene to inhibit calcium release and promote muscle relaxation, and managing any associated complications such as hyperkalemia and acidosis. Referral to a malignant hyperthermia center for further investigation is also recommended.

De Quervain’s tenosynovitis is a condition characterized by inflammation and thickening of the sheath that contains the tendons of the extensor pollicis brevis and abductor pollicis longus. This leads to pain on the radial side of the wrist. The condition is more commonly observed in men than women, particularly in the age group of 30 to 50 years. It is often associated with repetitive activities that involve pinching and grasping.

During examination, swelling and tenderness along the tendon sheath may be observed. The tendon sheath itself may also appear thickened. The most pronounced tenderness is usually felt over the tip of the radial styloid. A positive Finkelstein’s test, which involves flexing the wrist and moving it towards the ulnar side while the thumb is flexed across the palm, can help confirm the diagnosis.

Treatment for De Quervain’s tenosynovitis involves avoiding movements that can trigger symptoms and using a thumb splint to immobilize the thumb. In cases where symptoms persist, a local corticosteroid injection or surgical decompression may be considered.

The most probable diagnosis in this case is diabetic ketoacidosis (DKA). To confirm the diagnosis, it is necessary to establish that his blood glucose levels are elevated, he has significant ketonuria or ketonaemia, and that he is acidotic.

DKA is a life-threatening condition that occurs when there is a lack of insulin, leading to an inability to metabolize glucose. This results in high blood sugar levels and an osmotic diuresis, causing excessive thirst and increased urine production. Dehydration becomes inevitable when the urine output exceeds the patient’s ability to drink. Additionally, without insulin, fat becomes the primary energy source, leading to the production of large amounts of ketones and metabolic acidosis.

The key features of DKA include hyperglycemia (blood glucose > 11 mmol/l), ketonaemia (> 3 mmol/l) or significant ketonuria (> 2+ on urine dipstick), and acidosis (bicarbonate < 15 mmol/l and/or venous pH < 7.3). Clinical symptoms of DKA include nausea, vomiting, excessive thirst, excessive urine production, abdominal pain, signs of dehydration, a smell of ketones on breath (similar to pear drops), deep and rapid respiration (Kussmaul breathing), confusion or reduced consciousness, and tachycardia, hypotension, and shock. Investigations that should be performed include blood glucose measurement, urine dipstick (which will show marked glycosuria and ketonuria), blood ketone assay (more sensitive and specific than urine dipstick), blood tests (full blood count and urea and electrolytes), and arterial or venous blood gas analysis to assess for metabolic acidosis. The main principles of managing DKA are as follows: – Fluid boluses should only be given to reverse signs of shock and should be administered slowly in 10 ml/kg aliquots. If there are no signs of shock, fluid boluses should not be given, and specialist advice should be sought if a second bolus is required.
– Rehydration should be done with replacement therapy over 48 hours after signs of shock have been reversed.
– The first 20 ml/kg of fluid resuscitation should be given in addition to replacement fluid calculations and should not be subtracted from the calculations for the 48-hour fluid replacement.
– If a child in DKA shows signs of hypotensive shock, the use of inotropes may be considered.

To treat serious arrhythmia caused by hypomagnesaemia, it is recommended to administer 2 g of magnesium sulphate intravenously over a period of 10-15 minutes.

Further Reading:

In the management of respiratory and cardiac arrest, several drugs are commonly used to help restore normal function and improve outcomes. Adrenaline is a non-selective agonist of adrenergic receptors and is administered intravenously at a dose of 1 mg every 3-5 minutes. It works by causing vasoconstriction, increasing systemic vascular resistance (SVR), and improving cardiac output by increasing the force of heart contraction. Adrenaline also has bronchodilatory effects.

Amiodarone is another drug used in cardiac arrest situations. It blocks voltage-gated potassium channels, which prolongs repolarization and reduces myocardial excitability. The initial dose of amiodarone is 300 mg intravenously after 3 shocks, followed by a dose of 150 mg after 5 shocks.

Lidocaine is an alternative to amiodarone in cardiac arrest situations. It works by blocking sodium channels and decreasing heart rate. The recommended dose is 1 mg/kg by slow intravenous injection, with a repeat half of the initial dose after 5 minutes. The maximum total dose of lidocaine is 3 mg/kg.

Magnesium sulfate is used to reverse myocardial hyperexcitability associated with hypomagnesemia. It is administered intravenously at a dose of 2 g over 10-15 minutes. An additional dose may be given if necessary, but the maximum total dose should not exceed 3 g.

Atropine is an antagonist of muscarinic acetylcholine receptors and is used to counteract the slowing of heart rate caused by the parasympathetic nervous system. It is administered intravenously at a dose of 500 mcg every 3-5 minutes, with a maximum dose of 3 mg.

Naloxone is a competitive antagonist for opioid receptors and is used in cases of respiratory arrest caused by opioid overdose. It has a short duration of action, so careful monitoring is necessary. The initial dose of naloxone is 400 micrograms, followed by 800 mcg after 1 minute. The dose can be gradually escalated up to 2 mg per dose if there is no response to the preceding dose.

It is important for healthcare professionals to have knowledge of the pharmacology and dosing schedules of these drugs in order to effectively manage respiratory and cardiac arrest situations.

Generally speaking, if a child shows clinical signs of dehydration but does not exhibit shock, it can be assumed that they are 5% dehydrated. On the other hand, if shock is also present, it can be assumed that the child is 10% dehydrated or more. When we say 5% dehydration, it means that the body has lost 5 grams per 100 grams of body weight, which is equivalent to 50 milliliters per kilogram of fluid. Similarly, 10% dehydration implies a fluid loss of 100 milliliters per kilogram of fluid.

In the case of this child, they are 10% dehydrated, which means they have lost 100 milliliters per kilogram of fluid. Considering their weight of 30 kilograms, their estimated fluid loss amounts to 100 multiplied by 30, which equals 3000 milliliters.

Since this child is also in shock, they should receive a fluid bolus of 20 milliliters per kilogram. Therefore, the initial volume of fluid to administer would be 20 multiplied by 30 milliliters, resulting in 600 milliliters.

To summarize the clinical features of dehydration and shock, please refer below:

Dehydration (5%):
– The child appears unwell
– Normal heart rate or tachycardia
– Normal respiratory rate or tachypnea
– Normal peripheral pulses
– Normal or mildly prolonged capillary refill time (CRT)
– Normal blood pressure
– Warm extremities
– Decreased urine output
– Reduced skin turgor
– Sunken eyes
– Depressed fontanelle
– Dry mucous membranes

Clinical shock (10%):
– Pale, lethargic, mottled appearance
– Tachycardia
– Tachypnea
– Weak peripheral pulses
– Prolonged capillary refill time (CRT)
– Hypotension
– Cold extremities
– Decreased urine output
– Decreased level of consciousness

An abdominal aortic aneurysm (AAA) is a condition where the abdominal aorta becomes enlarged, either in a specific area or throughout its length, reaching 1.5 times its normal size. Most AAAs are found between the diaphragm and the point where the aorta splits into two branches. They can be classified into three types based on their location: suprarenal, pararenal, and infrarenal. Suprarenal AAAs involve the origin of one or more visceral arteries, pararenal AAAs involve the origins of the renal arteries, and infrarenal AAAs start below the renal arteries. The majority of AAAs (approximately 85%) are infrarenal. In individuals over 50 years old, a normal infrarenal aortic diameter is 1.7 cm in men and 1.5 cm in women. An infrarenal aorta with a diameter greater than 3 cm is considered to be an aneurysm. While most AAAs do not cause symptoms, an expanding aneurysm can sometimes lead to abdominal pain or pulsatile sensations. Symptomatic AAAs have a high risk of rupture. In the UK, elective surgery for AAAs is typically recommended if the aneurysm is larger than 5.5 cm in diameter or if it is larger than 4.5 cm in diameter and has increased in size by more than 0.5 cm in the past six months.

Hyperventilation leads to the constriction of blood vessels in the brain, which in turn reduces the flow and volume of blood in the brain, ultimately decreasing intracranial pressure (ICP). This is because hyperventilation lowers the levels of carbon dioxide (PaCO2) in the blood, resulting in an increase in pH and causing the arteries in the brain to constrict and reduce blood flow. As a result, cerebral blood volume and ICP decrease. The effects of hyperventilation are immediate, but they gradually diminish over a period of 6-24 hours as the brain adjusts its bicarbonate levels to normalize pH. However, caution must be exercised when discontinuing hyperventilation after a prolonged period, as the sudden increase in PaCO2 can lead to a rapid rise in cerebral blood flow and a detrimental increase in ICP.

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.

After the third shock is administered to patients with a shockable rhythm, it is recommended to administer two drugs: adrenaline and amiodarone. Adrenaline should be given at a dose of 1 mg intravenously (or intraosseously) for adult patients in cardiac arrest with a shockable rhythm. For adult patients in cardiac arrest who are in ventricular fibrillation or pulseless ventricular tachycardia, amiodarone should be given at a dose of 300 mg intravenously (or intraosseously) after three shocks have been administered. In cases where amiodarone is unavailable, lidocaine may be used as an alternative.

Further Reading:

Cardiopulmonary arrest is a serious event with low survival rates. In non-traumatic cardiac arrest, only about 20% of patients who arrest as an in-patient survive to hospital discharge, while the survival rate for out-of-hospital cardiac arrest is approximately 8%. The Resus Council BLS/AED Algorithm for 2015 recommends chest compressions at a rate of 100-120 per minute with a compression depth of 5-6 cm. The ratio of chest compressions to rescue breaths is 30:2.

After a cardiac arrest, the goal of patient care is to minimize the impact of post cardiac arrest syndrome, which includes brain injury, myocardial dysfunction, the ischaemic/reperfusion response, and the underlying pathology that caused the arrest. The ABCDE approach is used for clinical assessment and general management. Intubation may be necessary if the airway cannot be maintained by simple measures or if it is immediately threatened. Controlled ventilation is aimed at maintaining oxygen saturation levels between 94-98% and normocarbia. Fluid status may be difficult to judge, but a target mean arterial pressure (MAP) between 65 and 100 mmHg is recommended. Inotropes may be administered to maintain blood pressure. Sedation should be adequate to gain control of ventilation, and short-acting sedating agents like propofol are preferred. Blood glucose levels should be maintained below 8 mmol/l. Pyrexia should be avoided, and there is some evidence for controlled mild hypothermia but no consensus on this.

Post ROSC investigations may include a chest X-ray, ECG monitoring, serial potassium and lactate measurements, and other imaging modalities like ultrasonography, echocardiography, CTPA, and CT head, depending on availability and skills in the local department. Treatment should be directed towards the underlying cause, and PCI or thrombolysis may be considered for acute coronary syndrome or suspected pulmonary embolism, respectively.

Patients who are comatose after ROSC without significant pre-arrest comorbidities should be transferred to the ICU for supportive care. Neurological outcome at 72 hours is the best prognostic indicator of outcome.

Material risk refers to a significant potential for harm that a reasonable person would consider when deciding whether to undergo a medical or surgical treatment. It is an important factor to consider when obtaining consent for the treatment. Montgomery defines material risk as any risk that a reasonable person in the patient’s position would find significant. Relative risk, on the other hand, compares the risk between two different groups of people. Relative risk reduction measures the decrease in the risk of an adverse event in the treatment group compared to an untreated group. Side effect risk quantifies the likelihood of developing a side effect from a treatment, whether minor or major. Lastly, 1/ARR represents the number needed to treat in order to achieve a desired outcome.

Further Reading:

Patients have the right to determine what happens to their own bodies, and for consent to be valid, certain criteria must be met. These criteria include the person being informed about the intervention, having the capacity to consent, and giving consent voluntarily and freely without any pressure or undue influence.

In order for a person to be deemed to have capacity to make a decision on a medical intervention, they must be able to understand the decision and the information provided, retain that information, weigh up the pros and cons, and communicate their decision.

Valid consent can only be provided by adults, either by the patient themselves, a person authorized under a Lasting Power of Attorney, or someone with the authority to make treatment decisions, such as a court-appointed deputy or a guardian with welfare powers.

In the UK, patients aged 16 and over are assumed to have the capacity to consent. If a patient is under 18 and appears to lack capacity, parental consent may be accepted. However, a young person of any age may consent to treatment if they are considered competent to make the decision, known as Gillick competence. Parental consent may also be given by those with parental responsibility.

The Fraser guidelines apply to the prescription of contraception to under 16’s without parental involvement. These guidelines allow doctors to provide contraceptive advice and treatment without parental consent if certain criteria are met, including the young person understanding the advice, being unable to be persuaded to inform their parents, and their best interests requiring them to receive contraceptive advice or treatment.

Competent adults have the right to refuse consent, even if it is deemed unwise or likely to result in harm. However, there are exceptions to this, such as compulsory treatment authorized by the mental health act or if the patient is under 18 and refusing treatment would put their health at serious risk.

In emergency situations where a patient is unable to give consent, treatment may be provided without consent if it is immediately necessary to save their life or prevent a serious deterioration of their condition. Any treatment decision made without consent must be in the patient’s best interests, and if a decision is time-critical and the patient is unlikely to regain capacity in time, a best interest decision should be made. The treatment provided should be the least restrictive on the patient’s future choices.