A tension pneumothorax occurs when there is an air leak from the lung or chest wall that acts like a one-way valve. This causes air to build up in the pleural space without any way to escape. As a result, pressure in the pleural space increases and pushes the mediastinum into the opposite hemithorax. If left untreated, this can lead to cardiovascular instability, shock, and cardiac arrest.

The clinical features of tension pneumothorax include respiratory distress and cardiovascular instability. Tracheal deviation away from the side of the injury, unilateral absence of breath sounds on the affected side, and a hyper-resonant percussion note are also characteristic. Other signs include distended neck veins and cyanosis, which is a late sign. It’s important to note that both tension pneumothorax and massive haemothorax can cause decreased breath sounds on auscultation. However, percussion can help differentiate between the two conditions. Hyper-resonance suggests tension pneumothorax, while dullness suggests a massive haemothorax.

Tension pneumothorax is a clinical diagnosis and should not be delayed for radiological confirmation. Requesting a chest X-ray in this situation can delay treatment and put the patient at risk. Immediate decompression through needle thoracocentesis is the recommended treatment. Traditionally, a large-bore needle or cannula is inserted into the 2nd intercostal space in the midclavicular line of the affected hemithorax. However, studies on cadavers have shown better success in reaching the thoracic cavity when the 4th or 5th intercostal space in the midaxillary line is used in adult patients. ATLS now recommends this location for needle decompression in adults. The site for needle thoracocentesis in children remains the same, using the 2nd intercostal space in the midclavicular line. It’s important to remember that needle thoracocentesis is a temporary measure, and the insertion of a chest drain is the definitive treatment.

Intercostal artery laceration during the insertion of a chest drain is a potentially life-threatening complication. Although rare, it occurs more frequently than other complications mentioned. To minimize the risk of damage to underlying structures and unsightly scarring, the British Thoracic Society (BTS) recommends inserting chest drains within the safe triangle. This triangle is defined by the base of the axilla, the lateral border of the latissimus dorsi, the lateral border of the pectoralis major, and the 5th intercostal space.

Possible complications associated with the insertion of small-bore chest drains include puncture of the intercostal artery, organ perforation due to over-introduction of the dilator into the chest cavity, hospital-acquired pleural infection from non-aseptic techniques, inadequate stay suture leading to the chest tube falling out, and tube blockage, which may be more common with smaller bore Argyle drains.

When using an intercostal approach, it is important to place the chest drain closer to the superior border of the rib below in the intercostal space. This positioning helps avoid injury to the intercostal neurovascular bundle located under the costal groove of the rib above.

For more information, refer to the British Thoracic Society pleural disease guidelines.

A surgical cricothyroidotomy is a procedure performed in emergency situations to secure the airway by making an incision in the cricothyroid membrane. It is also known as an emergency surgical airway (ESA) and is typically done when intubation and oxygenation are not possible.

There are certain conditions in which a surgical cricothyroidotomy should not be performed. These include patients who are under 12 years old, those with laryngeal fractures or pre-existing or acute laryngeal pathology, individuals with tracheal transection and retraction of the trachea into the mediastinum, and cases where the anatomical landmarks are obscured due to trauma.

The procedure is carried out in the following steps:
1. Gathering and preparing the necessary equipment.
2. Positioning the patient on their back with the neck in a neutral position.
3. Sterilizing the patient’s neck using antiseptic swabs.
4. Administering local anesthesia, if time permits.
5. Locating the cricothyroid membrane, which is situated between the thyroid and cricoid cartilage.
6. Stabilizing the trachea with the left hand until it can be intubated.
7. Making a transverse incision through the cricothyroid membrane.
8. Inserting the scalpel handle into the incision and rotating it 90°. Alternatively, a haemostat can be used to open the airway.
9. Placing a properly-sized, cuffed endotracheal tube (usually a size 5 or 6) into the incision, directing it into the trachea.
10. Inflating the cuff and providing ventilation.
11. Monitoring for chest rise and auscultating the chest to ensure adequate ventilation.
12. Securing the airway to prevent displacement.

Potential complications of a surgical cricothyroidotomy include aspiration of blood, creation of a false passage into the tissues, subglottic stenosis or edema, laryngeal stenosis, hemorrhage or hematoma formation, laceration of the esophagus or trachea, mediastinal emphysema, and vocal cord paralysis or hoarseness.

Vestibular neuritis is a common complication of vestibular neuronitis, characterized by a following of people experiencing symptoms such as persistent dizziness, unsteadiness, and fear of falling. However, a rare complication called phobic postural vertigo may also occur, where individuals experience these symptoms despite not actually falling.

On the other hand, benign paroxysmal positional vertigo (BPPV) presents with short episodes of vertigo, usually lasting less than 20 seconds, triggered by changes in head position. In contrast, vestibular neuronitis causes constant vertigo, even when at rest, which can be worsened by head movements.

Recovery from vestibular neuronitis is a gradual process that typically takes a few weeks, up to 6 weeks. It is believed that this condition is caused by inflammation of the vestibular nerve following a viral infection. On the other hand, BPPV is thought to occur due to the presence of cellular debris or crystal formation in the semicircular canals.

Further Reading:

Vestibular neuritis, also known as vestibular neuronitis, is a condition characterized by sudden and prolonged vertigo of peripheral origin. It is believed to be caused by inflammation of the vestibular nerve, often following a viral infection. It is important to note that vestibular neuritis and labyrinthitis are not the same condition, as labyrinthitis involves inflammation of the labyrinth. Vestibular neuritis typically affects individuals between the ages of 30 and 60, with a 1:1 ratio of males to females. The annual incidence is approximately 3.5 per 100,000 people, making it one of the most commonly diagnosed causes of vertigo.

Clinical features of vestibular neuritis include nystagmus, which is a rapid, involuntary eye movement, typically in a horizontal or horizontal-torsional direction away from the affected ear. The head impulse test may also be positive. Other symptoms include spontaneous onset of rotational vertigo, which is worsened by changes in head position, as well as nausea, vomiting, and unsteadiness. These severe symptoms usually last for 2-3 days, followed by a gradual recovery over a few weeks. It is important to note that hearing is not affected in vestibular neuritis, and symptoms such as tinnitus and focal neurological deficits are not present.

Differential diagnosis for vestibular neuritis includes benign paroxysmal positional vertigo (BPPV), labyrinthitis, Meniere’s disease, migraine, stroke, and cerebellar lesions. Management of vestibular neuritis involves drug treatment for nausea and vomiting associated with vertigo, typically through short courses of medication such as prochlorperazine or cyclizine. If symptoms are severe and fluids cannot be tolerated, admission and administration of IV fluids may be necessary. General advice should also be given, including avoiding driving while symptomatic, considering the suitability to work based on occupation and duties, and the increased risk of falls. Follow-up is required, and referral is necessary if there are atypical symptoms, symptoms do not improve after a week of treatment, or symptoms persist for more than 6 weeks.

The prognosis for vestibular neuritis is generally good, with the majority of individuals fully recovering within 6 weeks. Recurrence is thought to occur in 2-11% of cases, and approximately 10% of individuals may develop BPPV following an episode of vestibular neuritis. A very rare complication of vestibular neuritis is ph

If you have missed one pill, which means it has been 48-72 hours since you took the last pill in your current packet or you started the first pill in a new packet 24-48 hours late, you need to take the missed pill as soon as you remember. Make sure to continue taking the remaining pills at your usual time. Emergency contraception is generally not necessary in this situation, but it may be worth considering if you have missed pills earlier in the packet or during the last week of the previous packet.

NSAIDs are known to have a relaxing effect on the ureter, but a randomized controlled trial found no difference between NSAIDs and a placebo in terms of this effect. Currently, only two classes of drugs, calcium channel blockers and alpha-blockers, are considered effective as medical expulsive therapy (MET). Calcium channel blockers work by blocking the active calcium channel pump that the smooth muscle of the ureter uses to contract, resulting in relaxation of the muscle and improved stone passage. Alpha-blockers, on the other hand, are commonly used as the first-line treatment to enhance stone passage. They reduce the basal tone of the ureter smooth muscle, decrease the frequency of peristaltic waves, and lower ureteric contraction. This leads to a decrease in intraureteric pressure below the stone, increasing the chances of stone passage. Patients treated with calcium channel blockers or alpha-blockers have been shown to have a 65% higher likelihood of spontaneous stone passage compared to those not given these medications.

Toxocariasis is a rare infection caused by the parasitic roundworm Toxocara canis. The main way it spreads to humans is through contact with dog feces. However, practicing good hand hygiene can help prevent transmission. While most people who come into contact with Toxocara canis don’t show any symptoms, a small number may experience a mild flu-like illness.

The most common presentation of toxocariasis is in children, who may experience unilateral visual loss. This loss of vision is typically caused by conditions such as vitritis, macular edema, and tractional retinal detachment. It is believed that these lesions occur due to a toxic or immunoallergic reaction to the larval antigens.

In this case, the administration of the local anesthetic used for the Bier’s block may have caused the patient’s blood to convert hemoglobin into methemoglobin, resulting in the observed skin color change.

Further Reading:

Bier’s block is a regional intravenous anesthesia technique commonly used for minor surgical procedures of the forearm or for reducing distal radius fractures in the emergency department (ED). It is recommended by NICE as the preferred anesthesia block for adults requiring manipulation of distal forearm fractures in the ED.

Before performing the procedure, a pre-procedure checklist should be completed, including obtaining consent, recording the patient’s weight, ensuring the resuscitative equipment is available, and monitoring the patient’s vital signs throughout the procedure. The air cylinder should be checked if not using an electronic machine, and the cuff should be checked for leaks.

During the procedure, a double cuff tourniquet is placed on the upper arm, and the arm is elevated to exsanguinate the limb. The proximal cuff is inflated to a pressure 100 mmHg above the systolic blood pressure, up to a maximum of 300 mmHg. The time of inflation and pressure should be recorded, and the absence of the radial pulse should be confirmed. 0.5% plain prilocaine is then injected slowly, and the time of injection is recorded. The patient should be warned about the potential cold/hot sensation and mottled appearance of the arm. After injection, the cannula is removed and pressure is applied to the venipuncture site to prevent bleeding. After approximately 10 minutes, the patient should have anesthesia and should not feel pain during manipulation. If anesthesia is successful, the manipulation can be performed, and a plaster can be applied by a second staff member. A check x-ray should be obtained with the arm lowered onto a pillow. The tourniquet should be monitored at all times, and the cuff should be inflated for a minimum of 20 minutes and a maximum of 45 minutes. If rotation of the cuff is required, it should be done after the manipulation and plaster application. After the post-reduction x-ray is satisfactory, the cuff can be deflated while observing the patient and monitors. Limb circulation should be checked prior to discharge, and appropriate follow-up and analgesia should be arranged.

There are several contraindications to performing Bier’s block, including allergy to local anesthetic, hypertension over 200 mm Hg, infection in the limb, lymphedema, methemoglobinemia, morbid obesity, peripheral vascular disease, procedures needed in both arms, Raynaud’s phenomenon, scleroderma, severe hypertension and sickle cell disease.

The first heart sound (S1) is created by vibrations produced when the mitral and tricuspid valves close. It occurs at the end of diastole and the start of ventricular systole, coming before the upstroke of the carotid pulsation.

A sample of the normal heart sounds can be listened to here (courtesy of Littman stethoscopes).

A loud S1 can be associated with the following conditions:
– Increased transvalvular gradient (e.g. mitral stenosis, tricuspid stenosis)
– Increased force of ventricular contraction (e.g. tachycardia, hyperdynamic states like fever and thyrotoxicosis)
– Shortened PR interval (e.g. Wolff-Parkinson-White syndrome)
– Mitral valve prolapse
– Thin individuals

A soft S1 can be associated with the following conditions:
– Inappropriate apposition of the AV valves (e.g. mitral regurgitation, tricuspid regurgitation)
– Prolonged PR interval (e.g. heart block, digoxin toxicity)
– Decreased force of ventricular contraction (e.g. myocarditis, myocardial infarction)
– Increased distance from the heart (e.g. obesity, emphysema, pericardial effusion)

A split S1 can be associated with the following conditions:
– Right bundle branch block
– LV pacing
– Ebstein anomaly

The Apgar score is a straightforward way to evaluate the well-being of a newborn baby right after birth. It consists of five criteria, each assigned a score ranging from zero to two. Typically, the assessment is conducted at one and five minutes after delivery, with the possibility of repeating it later if the score remains low. A score of 7 or higher is considered normal, while a score of 4-6 is considered fairly low, and a score of 3 or below is regarded as critically low. To remember the five criteria, you can use the acronym APGAR:

Appearance
Pulse rate
Grimace
Activity
Respiratory effort

The Apgar score criteria are as follows:

Score of 0:
Appearance (skin color): Blue or pale all over
Pulse rate: Absent
Reflex irritability (grimace): No response to stimulation
Activity: None
Respiratory effort: Absent

Score of 1:
Appearance (skin color): Blue at extremities (acrocyanosis)
Pulse rate: Less than 100 per minute
Reflex irritability (grimace): Grimace on suction or aggressive stimulation
Activity: Some flexion
Respiratory effort: Weak, irregular, gasping

Score of 2:
Appearance (skin color): No cyanosis, body and extremities pink
Pulse rate: More than 100 per minute
Reflex irritability (grimace): Cry on stimulation
Activity: Flexed arms and legs that resist extension
Respiratory effort: Strong, robust cry

When treating adults with bradycardia, it is recommended to administer a maximum of 6 doses of atropine 500 mcg. These doses can be repeated every 3-5 minutes. The total cumulative dose of atropine should not exceed 3 mg in adults.

Further Reading:

Causes of Bradycardia:
– Physiological: Athletes, sleeping
– Cardiac conduction dysfunction: Atrioventricular block, sinus node disease
– Vasovagal & autonomic mediated: Vasovagal episodes, carotid sinus hypersensitivity
– Hypothermia
– Metabolic & electrolyte disturbances: Hypothyroidism, hyperkalaemia, hypermagnesemia
– Drugs: Beta-blockers, calcium channel blockers, digoxin, amiodarone
– Head injury: Cushing’s response
– Infections: Endocarditis
– Other: Sarcoidosis, amyloidosis

Presenting symptoms of Bradycardia:
– Presyncope (dizziness, lightheadedness)
– Syncope
– Breathlessness
– Weakness
– Chest pain
– Nausea

Management of Bradycardia:
– Assess and monitor for adverse features (shock, syncope, myocardial ischaemia, heart failure)
– Treat reversible causes of bradycardia
– Pharmacological treatment: Atropine is first-line, adrenaline and isoprenaline are second-line
– Transcutaneous pacing if atropine is ineffective
– Other drugs that may be used: Aminophylline, dopamine, glucagon, glycopyrrolate

Bradycardia Algorithm:
– Follow the algorithm for management of bradycardia, which includes assessing and monitoring for adverse features, treating reversible causes, and using appropriate medications or pacing as needed.
https://acls-algorithms.com/wp-content/uploads/2020/12/Website-Bradycardia-Algorithm-Diagram.pdf

Le Fort fractures are intricate fractures of the midface, which involve the maxillary bone and the surrounding structures. These fractures can occur in a horizontal, pyramidal, or transverse direction. The distinguishing feature of Le Fort fractures is the separation of the pterygomaxillary due to trauma. They make up approximately 10% to 20% of all facial fractures and can have severe consequences, both in terms of potential life-threatening situations and disfigurement.

The causes of Le Fort fractures vary depending on the type of fracture. Common mechanisms include motor vehicle accidents, sports injuries, assaults, and falls from significant heights. Patients with Le Fort fractures often have concurrent head and cervical spine injuries. Additionally, they frequently experience other facial fractures, as well as neuromuscular injuries and dental avulsions.

The specific type of fracture sustained is determined by the direction of the force applied to the face. Le Fort type I fractures typically occur when a force is directed downward against the upper teeth. Le Fort type II fractures are usually the result of a force applied to the lower or mid maxilla. Lastly, Le Fort type III fractures are typically caused by a force applied to the nasal bridge and upper part of the maxilla.

Eclampsia is the most likely diagnosis in this case. It is characterized by the occurrence of one or more convulsions on top of pre-eclampsia. To control seizures in eclampsia, the recommended treatment is magnesium sulphate. The Collaborative Eclampsia Trial regimen should be followed for administering magnesium sulphate. Initially, a loading dose of 4 g should be given intravenously over 5 to 15 minutes. This should be followed by a continuous infusion of 1 g per hour for 24 hours. If the woman experiences another eclamptic seizure, the infusion should be continued for an additional 24 hours after the last seizure. In case of recurrent seizures, a further dose of 2-4 g should be administered intravenously over 5 to 15 minutes. It is important to note that the only cure for eclampsia is the delivery of the fetus and placenta. Once the patient is stabilized, she should be prepared for an emergency caesarean section.

Tonsillar herniation occurs when the cerebellar tonsils are pushed through the foramen magnum. This condition is characterized by a decrease in consciousness, respiratory arrest, and flaccid paralysis.

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.

The ratio of chest compressions to rescue breaths during CPR is now 30:2. Prior to 2005, the ratio used was 15:2.

Further Reading:

In the event of an adult experiencing cardiorespiratory arrest, it is crucial for doctors to be familiar with the Advanced Life Support (ALS) algorithm. They should also be knowledgeable about the proper technique for chest compressions, the appropriate rhythms for defibrillation, the reversible causes of arrest, and the drugs used in advanced life support.

During chest compressions, the rate should be between 100-120 compressions per minute, with a depth of compression of 5-6 cm. The ratio of chest compressions to rescue breaths should be 30:2. It is important to change the person giving compressions regularly to prevent fatigue.

There are two shockable ECG rhythms that doctors should be aware of: ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT). These rhythms require defibrillation.

There are four reversible causes of cardiorespiratory arrest, known as the 4 H’s and 4 T’s. The 4 H’s include hypoxia, hypovolemia, hypo or hyperkalemia or metabolic abnormalities, and hypothermia. The 4 T’s include thrombosis (coronary or pulmonary), tension pneumothorax, tamponade, and toxins. Identifying and treating these reversible causes is crucial for successful resuscitation.

When it comes to resus drugs, they are considered of secondary importance during CPR due to the lack of high-quality evidence for their efficacy. However, adrenaline (epinephrine) and amiodarone are the two drugs included in the ALS algorithm. Doctors should be familiar with the dosing, route, and timing of administration for both drugs.

Adrenaline should be administered intravenously at a concentration of 1 in 10,000 (100 micrograms/mL). It should be repeated every 3-5 minutes. Amiodarone is initially given at a dose of 300 mg, either from a pre-filled syringe or diluted in 20 mL of Glucose 5%. If required, an additional dose of 150 mg can be given by intravenous injection. This is followed by an intravenous infusion of 900 mg over 24 hours. The first dose of amiodarone is given after 3 shocks.

Homonymous quadrantanopia 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 quadrantanopia, while lesions in the parietal lobe can cause inferior homonymous quadrantanopia. The diagram below provides a summary of the different visual field defects resulting from lesions at various points in the visual pathway.

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.

Lithium is a commonly prescribed medication for bipolar disorder, as it helps stabilize mood. The recommended therapeutic range for lithium levels is typically between 0.4 and 0.8 mmol/l, although this range may vary depending on the laboratory. For maintenance therapy and treatment in older individuals, the lower end of the range is usually targeted. Toxic effects of lithium are typically observed when levels exceed 1.5 mmol/l. It is important to monitor lithium levels one week after starting therapy and after any dosage adjustments.

One potential side effect of lithium is the development of nephrogenic diabetes insipidus, a condition that affects the kidneys’ ability to concentrate urine. However, lithium does not cause diabetes mellitus. Another known side effect is hypothyroidism, which is a decrease in thyroid hormone production, but it does not lead to hyperthyroidism, an overactive thyroid.

Signs of lithium toxicity include nausea, vomiting, diarrhea, tremors, ataxia (loss of coordination), confusion, increased muscle tone, clonus (repetitive, involuntary muscle contractions), nephrogenic diabetes insipidus, convulsions, coma, and renal failure. It is crucial to be aware of these symptoms and seek medical attention if they occur.

Urticaria is a skin condition characterized by red, raised, and itchy rashes that can appear in specific areas or all over the body. It is a common issue, affecting around 15% of individuals at some point in their lives. Urticaria can be either acute or chronic, with the acute form being more prevalent.

According to the current guidelines from the National Institute for Health and Care Excellence (NICE), individuals seeking treatment for urticaria should be offered a non-sedating antihistamine from the second-generation category. Examples of second-generation antihistamines include cetirizine, loratadine, fexofenadine, desloratadine, and levocetirizine.

It is no longer recommended to use conventional first-generation antihistamines like promethazine and chlorpheniramine for urticaria. These medications have short-lasting effects, can cause sedation and anticholinergic side effects, and may interfere with sleep, learning, and performance. They can also interact negatively with alcohol and other medications. Additionally, there have been reports of lethal overdoses with first-generation antihistamines. Terfenadine and astemizole should also be avoided as they can have harmful effects on the heart when combined with certain drugs like erythromycin and ketoconazole.

In cases where symptoms are severe, a short course of oral corticosteroids such as prednisolone (40 mg for up to seven days) may be prescribed alongside the second-generation antihistamine.

The combination of tests points to conductive hearing loss in the right ear. There is no indication from these tests of sensorineural loss in the left ear, as a positive Rinne test (AC > BC) in the left ear is typical of normal hearing or sensorineural loss (but sensorineural loss would not result in lateralization in Weber test). Thus, the correct inference is:

Conductive hearing loss in the right ear.

Further Reading:

Hearing loss is a common complaint that can be caused by various conditions affecting different parts of the ear and nervous system. The outer ear is the part of the ear outside the eardrum, while the middle ear is located between the eardrum and the cochlea. The inner ear is within the bony labyrinth and consists of the vestibule, semicircular canals, and cochlea. The vestibulocochlear nerve connects the inner ear to the brain.

Hearing loss can be classified based on severity, onset, and type. Severity is determined by the quietest sound that can be heard, measured in decibels. It can range from mild to profound deafness. Onset can be sudden, rapidly progressive, slowly progressive, or fluctuating. Type of hearing loss can be either conductive or sensorineural. Conductive hearing loss is caused by issues in the external ear, eardrum, or middle ear that disrupt sound transmission. Sensorineural hearing loss is caused by problems in the cochlea, auditory nerve, or higher auditory processing pathways.

To diagnose sensorineural and conductive deafness, a 512 Hz tuning fork is used to perform Rinne and Weber’s tests. These tests help determine the type of hearing loss based on the results. In Rinne’s test, air conduction (AC) and bone conduction (BC) are compared, while Weber’s test checks for sound lateralization.

Cholesteatoma is a condition characterized by the abnormal accumulation of skin cells in the middle ear or mastoid air cell spaces. It is believed to develop from a retraction pocket that traps squamous cells. Cholesteatoma can cause the accumulation of keratin and the destruction of adjacent bones and tissues due to the production of destructive enzymes. It can lead to mixed sensorineural and conductive deafness as it affects both the middle and inner ear.

DKA is characterized by three main symptoms: high blood sugar levels (hyperglycemia), an acidic pH in the body (acidosis), and an increased presence of ketones in the blood (ketonaemia).

Further Reading:

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

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

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

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

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

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

Activated charcoal prevents the absorption of poisons by absorbing them onto its surface through weak electrostatic forces.

Further Reading:

Poisoning in the emergency department is often caused by accidental or intentional overdose of prescribed drugs. Supportive treatment is the primary approach for managing most poisonings. This includes ensuring a clear airway, proper ventilation, maintaining normal fluid levels, temperature, and blood sugar levels, correcting any abnormal blood chemistry, controlling seizures, and assessing and treating any injuries.

In addition to supportive treatment, clinicians may need to consider strategies for decontamination, elimination, and administration of antidotes. Decontamination involves removing poisons from the skin or gastrointestinal tract. This can be done through rinsing the skin or using methods such as activated charcoal, gastric lavage, induced emesis, or whole bowel irrigation. However, induced emesis is no longer commonly used, while gastric lavage and whole bowel irrigation are rarely used.

Elimination methods include urinary alkalinization, hemodialysis, and hemoperfusion. These techniques help remove toxins from the body.

Activated charcoal is a commonly used method for decontamination. It works by binding toxins in the gastrointestinal tract, preventing their absorption. It is most effective if given within one hour of ingestion. However, it is contraindicated in patients with an insecure airway due to the risk of aspiration. Activated charcoal can be used for many drugs, but it is ineffective for certain poisonings, including pesticides (organophosphates), hydrocarbons, strong acids and alkalis, alcohols (ethanol, methanol, ethylene glycol), iron, lithium, and solvents.

Antidotes are specific treatments for poisoning caused by certain drugs or toxins. For example, cyanide poisoning can be treated with dicobalt edetate, hydroxocobalamin, or sodium nitrite and sodium thiosulphate. Benzodiazepine poisoning can be treated with flumazanil, while opiate poisoning can be treated with naloxone. Other examples include protamine for heparin poisoning, vitamin K or fresh frozen plasma for warfarin poisoning, fomepizole or ethanol for methanol poisoning, and methylene blue for methemoglobinemia caused by benzocaine or nitrates.

There are many other antidotes available for different types of poisoning, and resources such as TOXBASE and the National Poisons Information Service (NPIS) can provide valuable advice on managing poisonings.

Hereditary angioedema (HAE) mainly affects the respiratory, gastrointestinal, and integumentary systems. This condition primarily impacts the respiratory system, gastrointestinal system, and the skin.

Further Reading:
Angioedema and urticaria are related conditions that involve swelling in different layers of tissue. Angioedema refers to swelling in the deeper layers of tissue, such as the lips and eyelids, while urticaria, also known as hives, refers to swelling in the epidermal skin layers, resulting in raised red areas of skin with itching. These conditions often coexist and may have a common underlying cause.

Angioedema can be classified into allergic and non-allergic types. Allergic angioedema is the most common type and is usually triggered by an allergic reaction, such as to certain medications like penicillins and NSAIDs. Non-allergic angioedema has multiple subtypes and can be caused by factors such as certain medications, including ACE inhibitors, or underlying conditions like hereditary angioedema (HAE) or acquired angioedema.

HAE is an autosomal dominant disease characterized by a deficiency of C1 esterase inhibitor. It typically presents in childhood and can be inherited or acquired as a result of certain disorders like lymphoma or systemic lupus erythematosus. Acquired angioedema may have similar clinical features to HAE but is caused by acquired deficiencies of C1 esterase inhibitor due to autoimmune or lymphoproliferative disorders.

The management of urticaria and allergic angioedema focuses on ensuring the airway remains open and addressing any identifiable triggers. In mild cases without airway compromise, patients may be advised that symptoms will resolve without treatment. Non-sedating antihistamines can be used for up to 6 weeks to relieve symptoms. Severe cases of urticaria may require systemic corticosteroids in addition to antihistamines. In moderate to severe attacks of allergic angioedema, intramuscular epinephrine may be considered.

The management of HAE involves treating the underlying deficiency of C1 esterase inhibitor. This can be done through the administration of C1 esterase inhibitor, bradykinin receptor antagonists, or fresh frozen plasma transfusion, which contains C1 inhibitor.

In summary, angioedema and urticaria are related conditions involving swelling in different layers of tissue. They can coexist and may have a common underlying cause. Management involves addressing triggers, using antihistamines, and in severe cases, systemic corticosteroids or other specific treatments for HAE.

Lactulose and the oral antibiotic Rifaximin are commonly prescribed to patients with hepatic encephalopathy. The main goal of treatment for this condition is to identify and address any factors that may have triggered it. Lactulose is administered to relieve constipation, which can potentially lead to hepatic encephalopathy. On the other hand, Rifaximin is used to decrease the presence of enteric bacteria that produce ammonia.

Further Reading:

Cirrhosis is a condition where the liver undergoes structural changes, resulting in dysfunction of its normal functions. It can be classified as either compensated or decompensated. Compensated cirrhosis refers to a stage where the liver can still function effectively with minimal symptoms, while decompensated cirrhosis is when the liver damage is severe and clinical complications are present.

Cirrhosis develops over a period of several years due to repeated insults to the liver. Risk factors for cirrhosis include alcohol misuse, hepatitis B and C infection, obesity, type 2 diabetes, autoimmune liver disease, genetic conditions, certain medications, and other rare conditions.

The prognosis of cirrhosis can be assessed using the Child-Pugh score, which predicts mortality based on parameters such as bilirubin levels, albumin levels, INR, ascites, and encephalopathy. The score ranges from A to C, with higher scores indicating a poorer prognosis.

Complications of cirrhosis include portal hypertension, ascites, hepatic encephalopathy, variceal hemorrhage, increased infection risk, hepatocellular carcinoma, and cardiovascular complications.

Diagnosis of cirrhosis is typically done through liver function tests, blood tests, viral hepatitis screening, and imaging techniques such as transient elastography or acoustic radiation force impulse imaging. Liver biopsy may also be performed in some cases.

Management of cirrhosis involves treating the underlying cause, controlling risk factors, and monitoring for complications. Complications such as ascites, spontaneous bacterial peritonitis, oesophageal varices, and hepatic encephalopathy require specific management strategies.

Overall, cirrhosis is a progressive condition that requires ongoing monitoring and management to prevent further complications and improve outcomes for patients.

Schistosomiasis, also known as bilharzia, is a tropical disease caused by parasitic trematodes (flukes) of the Schistosoma type. It is transmitted through contaminated water that has been contaminated with faeces or urine containing eggs. The disease requires a specific freshwater snail as an intermediate host and human contact with water inhabited by the snail. There are five species of Schistosoma that cause human disease: S. japonicum, S. mansoni, S. haematobium, S. intercalatum, and S. mekongi. Schistosomiasis is a significant public health issue, second only to malaria, with over 200 million people infected worldwide. It is prevalent in the Middle East, Africa, and parts of South America and the Caribbean. Infection can manifest as acute or chronic.

Acute schistosomiasis is characterized by the early clinical sign of swimmers itch, which causes blisters and an urticarial response in the area where the parasite enters the skin. Most acute infections are asymptomatic, but some patients may develop an acute syndrome. The most common acute syndrome is known as Katayama fever, which typically occurs in individuals with no previous exposure. It is caused by an allergic reaction to the sudden release of highly antigenic eggs and usually presents a few weeks after initial exposure to S. japonicum. Symptoms of Katayama fever include fever, flu-like illness, arthralgia, myalgia, abdominal pain, diarrhea, and cough. Patients may also experience right upper quadrant tenderness and hepatosplenomegaly. An extremely high eosinophil count is commonly observed.

Chronic schistosomiasis can manifest as intestinal or urogenital forms. Intestinal schistosomiasis occurs when adult worms migrate from the liver to the mesenteric venules, where female worms continuously lay eggs. Common symptoms include abdominal pain and bloody diarrhea. Advanced cases may present with hepatosplenomegaly and portal hypertension. Schistosomiasis is the second most common cause of oesophageal varices worldwide. Urogenital schistosomiasis occurs when adult worms migrate to the vesical plexus. The hallmark sign is haematuria. In women, it may cause genital and vaginal lesions, as well as dyspareunia.

Hyperosmolar hyperglycaemic state (HHS) is a condition characterized by extremely high blood sugar levels, dehydration, and increased osmolality without significant ketosis. In this patient, the symptoms are consistent with HHS as they have high blood sugar levels without significant ketoacidosis (pH is above 7.3 and ketones are less than 3 mmol/L). Additionally, they show signs of dehydration with low blood pressure and a fast heart rate. The osmolality is calculated to be equal to or greater than 320 mosmol/kg, indicating increased concentration of solutes in the blood.

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.

According to NICE, one of the recommended treatments for mild-to-moderate Alzheimer’s disease is the use of acetylcholinesterase (AChE) inhibitors. These inhibitors include Donepezil (Aricept), Galantamine, and Rivastigmine. They work by inhibiting the enzyme that breaks down acetylcholine, a neurotransmitter involved in memory and cognitive function.

On the other hand, Memantine is a different type of medication that acts by blocking NMDA-type glutamate receptors. It is recommended for patients with moderate Alzheimer’s disease who cannot tolerate or have a contraindication to AChE inhibitors, or for those with severe Alzheimer’s disease.

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

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

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

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

This patient presents with symptoms and signs that are consistent with an atypical pneumonia, most likely caused by an infection with Mycoplasma pneumoniae. The clinical features of Mycoplasma pneumoniae infection include a flu-like illness that precedes respiratory symptoms, along with fever, myalgia, headache, diarrhea, and cough (initially dry but often becoming productive). Focal chest signs typically develop later in the course of the illness.

Mycoplasma pneumoniae infection is commonly associated with the development of erythema multiforme, a rash characterized by multiple red lesions on the limbs that evolve into target lesions a few days after the rash appears. Additionally, this infection can also cause Steven-Johnson syndrome. It is worth noting that haemolytic anaemia with cold agglutinins can complicate Mycoplasma pneumoniae infections, providing further evidence for the diagnosis.

The recommended first-line antibiotic for treating this case would be a macrolide, such as clarithromycin. Doxycycline can also be used but is generally considered a second-line option.

Gout and pseudogout are both characterized by the presence of crystal deposits in the joints that are affected. Gout occurs when urate crystals are deposited, while pseudogout occurs when calcium pyrophosphate crystals are deposited. Under a microscope, these crystals can be distinguished by their appearance. Urate crystals are needle-shaped and negatively birefringent, while calcium pyrophosphate crystals are brick-shaped and positively birefringent.

Gout can affect any joint in the body, but it most commonly manifests in the hallux metatarsophalangeal joint, which is the joint at the base of the big toe. This joint is affected in approximately 50% of gout cases. On the other hand, pseudogout primarily affects the larger joints, such as the knee.