Prinzmetal angina is a rare form of angina that typically occurs during periods of rest, specifically between midnight and early morning. The attacks can be severe and happen in clusters. This condition is caused by spasms in the coronary arteries, even though patients may have normal arteries. The main treatment options for controlling these spasms are calcium-channel blockers and nitrates. The spasms often follow a cyclical pattern and may disappear after a few months, only to reappear later on.

Unstable angina may present similarly to Prinzmetal angina, but it does not exclusively occur at night and the exercise tolerance test results are typically abnormal.

Decubitus angina, on the other hand, is angina that occurs when lying down. It is often a result of cardiac failure caused by increased intravascular volume, which puts extra strain on the heart.

Takotsubo cardiomyopathy, also known as acute stress cardiomyopathy, can present in a manner similar to an acute myocardial infarction. The cause of this condition is unknown, but it tends to occur in individuals who have recently experienced significant emotional or physical stress. The term Takotsubo refers to the shape the left ventricle takes on, resembling an octopus pot with a narrow neck and round bottom. ECGs often show characteristic changes, such as ST-elevation, but subsequent angiograms reveal normal coronary arteries. The diagnosis is confirmed when the angiogram shows the distinctive octopus pot shape of the left ventricle.

There is no indication of a psychogenic cause in this particular case.

The nerve agents, also known as nerve gases, are a group of highly toxic chemical warfare agents that were initially developed just before and during World War II.

The first compounds to be created are referred to as the G agents (with G representing German, as they were discovered and synthesized by German scientists). These include Tabun (GA), Sarin (GB), and Soman (GD).

In the 1950s, the V agents (with V standing for venomous) were synthesized, and they are approximately 10 times more poisonous than sarin. These include Venomous agent X (VX), Venomous agent E (VE), Venomous agent G (VG), and Venomous agent M (VM).

One of the most well-known incidents involving the use of a nerve agent was the March 1995 Tokyo subway sarin attack. During this attack, Sarin was released into the Tokyo subway system during rush hour. As a result, over 5,000 people sought medical attention. Among them, 984 were moderately poisoned, 54 were severely poisoned, and 12 lost their lives.

The nerve agents are organophosphorus esters that are chemically related to organophosphorus insecticides. They work by inhibiting acetylcholinesterase (AChE), an enzyme that breaks down the neurotransmitter acetylcholine (ACh). This leads to an accumulation of ACh at both muscarinic and nicotinic cholinergic receptors.

Nerve agents can be absorbed through any body surface. When dispersed as a spray or aerosol, they can be absorbed through the skin, eyes, and respiratory tract. When dispersed as a vapor, they are primarily absorbed through the respiratory tract and eyes. If a sufficient amount of agent is absorbed, local effects are followed by generalized systemic effects.

Theophylline is a medication used to treat severe asthma. It is a bronchodilator that comes in modified-release forms, which can maintain therapeutic levels in the blood for 12 hours. Theophylline works by inhibiting phosphodiesterase and blocking the breakdown of cyclic AMP. It also competes with adenosine on A1 and A2 receptors.

Achieving the right dose of theophylline can be challenging because there is a narrow range between therapeutic and toxic levels. The half-life of theophylline can be influenced by various factors, further complicating dosage adjustments. It is recommended to aim for serum levels of 10-20 mg/l six to eight hours after the last dose.

Unlike many other medications, the specific brand of theophylline can significantly impact its effects. Therefore, it is important to prescribe theophylline by both its brand name and generic name.

Several factors can increase the half-life of theophylline, including heart failure, cirrhosis, viral infections, and certain drugs. Conversely, smoking, heavy drinking, and certain medications can decrease the half-life of theophylline.

There are several drugs that can either increase or decrease the plasma concentration of theophylline. Calcium channel blockers, cimetidine, fluconazole, macrolides, methotrexate, and quinolones can increase the concentration. On the other hand, carbamazepine, phenobarbitol, phenytoin, rifampicin, and St. John’s wort can decrease the concentration.

The clinical symptoms of theophylline toxicity are more closely associated with acute overdose rather than chronic overexposure. Common symptoms include headache, dizziness, nausea, vomiting, abdominal pain, rapid heartbeat, dysrhythmias, seizures, mild metabolic acidosis, low potassium, low magnesium, low phosphates, abnormal calcium levels, and high blood sugar.

Seizures are more prevalent in acute overdose cases, while chronic overdose typically presents with minimal gastrointestinal symptoms. Cardiac dysrhythmias are more common in chronic overdose situations compared to acute overdose.

Methaemoglobinaemia is a condition characterized by various symptoms such as headache, anxiety, acidosis, arrhythmia, seizure activity, reduced consciousness or coma. One notable feature is the presence of brown or chocolate coloured blood. It is important to note that the patient is taking chloroquine, which is a known trigger for methaemoglobinaemia. Additionally, despite the condition, the patient’s arterial blood gas analysis shows a normal partial pressure of oxygen.

Further Reading:

Methaemoglobinaemia is a condition where haemoglobin is oxidised from Fe2+ to Fe3+. This process is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin, converting it back to haemoglobin. In healthy individuals, methaemoglobin levels are typically less than 1% of total haemoglobin. However, an increase in methaemoglobin can lead to tissue hypoxia as Fe3+ cannot bind oxygen effectively.

Methaemoglobinaemia can be congenital or acquired. Congenital causes include haemoglobin chain variants (HbM, HbH) and NADH methaemoglobin reductase deficiency. Acquired causes can be due to exposure to certain drugs or chemicals, such as sulphonamides, local anaesthetics (especially prilocaine), nitrates, chloroquine, dapsone, primaquine, and phenytoin. Aniline dyes are also known to cause methaemoglobinaemia.

Clinical features of methaemoglobinaemia include slate grey cyanosis (blue to grey skin coloration), chocolate blood or chocolate cyanosis (brown color of blood), dyspnoea, low SpO2 on pulse oximetry (which often does not improve with supplemental oxygen), and normal PaO2 on arterial blood gas (ABG) but low SaO2. Patients may tolerate hypoxia better than expected. Severe cases can present with acidosis, arrhythmias, seizures, and coma.

Diagnosis of methaemoglobinaemia is made by directly measuring the level of methaemoglobin using a co-oximeter, which is present in most modern blood gas analysers. Other investigations, such as a full blood count (FBC), electrocardiogram (ECG), chest X-ray (CXR), and beta-human chorionic gonadotropin (bHCG) levels (in pregnancy), may be done to assess the extent of the condition and rule out other contributing factors.

Active treatment is required if the methaemoglobin level is above 30% or if it is below 30% but the patient is symptomatic or shows evidence of tissue hypoxia. Treatment involves maintaining the airway and delivering high-flow oxygen, removing the causative agents, treating toxidromes and consider giving IV dextrose 5%.

Nasopharyngeal airway adjuncts (NPAs) are selected based on their length, which should match the distance between the nostril and the tragus of the ear.

Further Reading:

Techniques to keep the airway open:

1. Suction: Used to remove obstructing material such as blood, vomit, secretions, and food debris from the oral cavity.

2. Chin lift manoeuvres: Involves lifting the head off the floor and lifting the chin to extend the head in relation to the neck. Improves alignment of the pharyngeal, laryngeal, and oral axes.

3. Jaw thrust: Used in trauma patients with cervical spine injury concerns. Fingers are placed under the mandible and gently pushed upward.

Airway adjuncts:

1. Oropharyngeal airway (OPA): Prevents the tongue from occluding the airway. Sized according to the patient by measuring from the incisor teeth to the angle of the mandible. Inserted with the tip facing backwards and rotated 180 degrees once it touches the back of the palate or oropharynx.

2. Nasopharyngeal airway (NPA): Useful when it is difficult to open the mouth or in semi-conscious patients. Sized by length (distance between nostril and tragus of the ear) and diameter (roughly that of the patient’s little finger). Contraindicated in basal skull and midface fractures.

Laryngeal mask airway (LMA):

– Supraglottic airway device used as a first line or rescue airway.
– Easy to insert, sized according to patient’s bodyweight.
– Advantages: Easy insertion, effective ventilation, some protection from aspiration.
– Disadvantages: Risk of hypoventilation, greater gastric inflation than endotracheal tube (ETT), risk of aspiration and laryngospasm.

Note: Proper training and assessment of the patient’s condition are essential for airway management.

Hereditary angioedema is a condition caused by a lack of C1 esterase inhibitor, a protein that is part of the complement system. It is typically inherited in an autosomal dominant manner. Symptoms usually start in childhood and continue sporadically into adulthood. Attacks can be triggered by minor surgical procedures, dental work, and stress. The main clinical signs of hereditary angioedema include swelling of the skin and mucous membranes, with the face, tongue, and extremities being the most commonly affected areas. There is often a tingling sensation before an attack, sometimes accompanied by a non-itchy rash.

Angioedema and anaphylaxis resulting from C1 esterase inhibitor deficiency do not respond to adrenaline, steroids, or antihistamines. Treatment requires the use of C1 esterase inhibitor concentrate or fresh frozen plasma, both of which contain C1 esterase inhibitor. In situations that may trigger an attack, short-term prophylaxis can be achieved by administering C1 esterase inhibitor or fresh frozen plasma infusions prior to the event. For long-term prevention, androgenic steroids like stanozolol or antifibrinolytic drugs such as tranexamic acid can be used.

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.

A Focussed Assessment with Sonography for Trauma (FAST) scan is a point-of-care ultrasound examination conducted when a trauma patient arrives. Its primary purpose is to identify the presence of intra-abdominal free fluid, which is typically assumed to be haemoperitoneum in the context of trauma. This information is crucial for making decisions regarding further management of the patient.

The sensitivity of FAST scanning for detecting intraperitoneal fluid is approximately 90%, while its specificity is around 95%. However, its sensitivity for detecting solid organ injuries is much lower. As a result, FAST scanning has largely replaced diagnostic peritoneal lavage as the preferred initial method for assessing haemoperitoneum.

During a standard FAST scan, four regions are examined. The subxiphoid transverse view is used to assess for pericardial effusion and left lobe liver injuries. The longitudinal view of the right upper quadrant helps identify right liver injuries, right kidney injury, and fluid in the hepatorenal recess (Morison’s pouch). The longitudinal view of the left upper quadrant is used to assess for splenic injury and left kidney injury. Lastly, the transverse and longitudinal views of the suprapubic region are used to examine the bladder and fluid in the pouch of Douglas.

In addition to the standard FAST scan, an extended FAST or eFAST may be performed to assess the left and right thoracic regions. This helps determine the presence of pneumothorax and haemothorax.

The hepatorenal recess is the deepest part of the peritoneal cavity when the patient is lying flat. Consequently, it is the most likely area for fluid to accumulate.

The patient has presented with a facial palsy that affects only the left side and involves the lower motor neurons. This can be distinguished from an upper motor neuron lesion because the patient is unable to raise their eyebrow and the upper facial muscles are also affected. Additionally, the patient demonstrates a phenomenon known as Bell’s phenomenon, where the eye on the affected side rolls upwards and outwards when attempting to close the eye and bare the teeth.

Approximately 80% of sudden onset lower motor neuron facial palsies are attributed to Bell’s palsy. It is believed that this condition is caused by swelling of the facial nerve within the petrous temporal bone, which is secondary to a latent herpesvirus, specifically HSV-1 and HZV.

There are other potential causes for an isolated lower motor neuron facial nerve palsy, including Ramsay-Hunt syndrome (caused by the herpes zoster virus), trauma, parotid gland tumor, cerebellopontine angle tumor (such as an acoustic neuroma), middle ear infection, cholesteatoma, and sarcoidosis.

However, Ramsay-Hunt syndrome is unlikely in this case since there is no presence of pain or pustular lesions in and around the ear. An acoustic neuroma is also less likely, especially without any symptoms of sensorineural deafness or tinnitus. Furthermore, there are no clinical features consistent with an inner ear infection.

The recommended treatment for this patient is the administration of steroids, and appropriate follow-up should be organized.

Acute kidney injury (AKI), previously known as acute renal failure, is a sudden decline in kidney function that leads to the accumulation of waste products and disturbances in fluid and electrolyte balance. This can occur in individuals with previously normal kidney function or those with pre-existing kidney disease (acute-on-chronic kidney disease). AKI is relatively common, affecting approximately 15% of adults admitted to hospitals in the UK.

The clinical presentation of AKI varies depending on the underlying cause and the severity of the condition. Typically, patients experience reduced urine output (oliguria or anuria) along with an increase in serum creatinine levels. AKI is diagnosed when at least one of the following criteria is met: a rise in serum creatinine of 26 μmol/L or more within 48 hours, a 50% or greater increase in serum creatinine (1.5 times the baseline) within the previous seven days, or a decrease in urine output to less than 0.5 mL/kg/hour for more than six hours.

Common symptoms of AKI include reduced urine output, which is usually oliguria or anuria. However, polyuria can also occur due to impaired fluid reabsorption by damaged renal tubules or the osmotic effect of accumulated metabolites. Abrupt anuria may indicate an acute obstruction, severe glomerulonephritis, or renal artery occlusion, while a gradual decrease in urine output may suggest a urethral stricture or bladder outlet obstruction, such as benign prostatic hyperplasia. Other symptoms may include nausea, vomiting, dehydration, and confusion.

Signs of AKI can include hypertension, a palpable bladder if urinary retention is present, dehydration with postural hypotension and no swelling, or fluid overload with elevated jugular venous pressure (JVP), pulmonary edema, and peripheral edema.