A summary of the vessels involved in different types of myocardial infarction, along with the corresponding ECG leads and the location of the infarction.

For instance, an anteroseptal infarction involving the left anterior descending artery is indicated by ECG leads V1-V3. Similarly, an anterior infarction involving the left anterior descending artery is indicated by leads V3-V4.

In cases of anterolateral infarctions, both the left anterior descending artery and the left circumflex artery are involved, and this is reflected in ECG leads V5-V6. An extensive anterior infarction involving the left anterior descending artery is indicated by leads V1-V6.

Lateral infarcts involving the left circumflex artery are indicated by leads I, II, aVL, and V6. Inferior infarctions, on the other hand, involve either the right coronary artery (in 80% of cases) or the left circumflex artery (in 20% of cases), and this is shown by leads II, III, and aVF.

In the case of a right ventricular infarction, the right coronary artery is involved, and this is indicated by leads V1 and V4R. Lastly, a posterior infarction involving the right coronary artery is shown by leads V7-V9.

This patient is showing significant signs of distress, including a highly elevated heart rate and respiratory rate, as well as very little urine output. Additionally, they are experiencing drowsiness, lethargy, and confusion. These symptoms indicate that the patient has suffered a class IV haemorrhage at this stage.

Recognizing the extent of blood loss based on vital signs and mental status abnormalities is a crucial skill. The Advanced Trauma Life Support (ATLS) classification for haemorrhagic shock correlates the amount of blood loss with expected physiological responses in a healthy 70 kg patient. In a 70 kg male patient, the total circulating blood volume is approximately five litres, accounting for around 7% of their total body weight.

The ATLS haemorrhagic shock classification is summarized as follows:

CLASS I
Blood loss (mL): Up to 750
Blood loss (% blood volume): Up to 15%
Pulse rate (bpm): <100
Systolic BP: Normal
Pulse pressure: Normal (or increased)
Respiratory rate: 14-20
Urine output (ml/hr): >30
CNS/mental status: Slightly anxious

CLASS II
Blood loss (mL): 750-1500
Blood loss (% blood volume): 15-30%
Pulse rate (bpm): 100-120
Systolic BP: Normal
Pulse pressure: Decreased
Respiratory rate: 20-30
Urine output (ml/hr): 20-30
CNS/mental status: Mildly anxious

CLASS III
Blood loss (mL): 1500-2000
Blood loss (% blood volume): 30-40%
Pulse rate (bpm): 120-140
Systolic BP: Decreased
Pulse pressure: Decreased
Respiratory rate: 30-40
Urine output (ml/hr): 5-15
CNS/mental status: Anxious, confused

CLASS IV
Blood loss (mL): >2000
Blood loss (% blood volume): >40%
Pulse rate (bpm): >140
Systolic BP: Decreased
Pulse pressure: Decreased
Respiratory rate: >40
Urine output (ml/hr): Negligible
CNS/mental status: Confused, lethargic

Spontaneous bacterial peritonitis (SBP) is a sudden bacterial infection of the fluid in the abdomen. It typically occurs in patients with high blood pressure in the portal vein, and about 70% of cases are seen in patients with severe liver disease. In any given year, around 30% of patients with fluid buildup in the abdomen will develop SBP.

SBP can present with a wide range of symptoms, so it’s important to be vigilant when caring for patients with fluid buildup in the abdomen, especially if there is a sudden decline in their condition. Some patients may not show any symptoms at all.

Common clinical features of SBP include fever (80% of cases), abdominal pain (70% of cases), worsening or unexplained confusion due to liver dysfunction, diarrhea, nausea and vomiting, and bowel obstruction.

There are several factors that increase the risk of developing SBP, including severe liver disease (Child-Pugh class C), gastrointestinal bleeding, urinary tract infection, excessive growth of bacteria in the intestines, presence of indwelling lines such as central venous catheters or urinary catheters, previous episodes of SBP, and low levels of protein in the fluid buildup in the abdomen.

To diagnose SBP, a procedure called abdominal paracentesis is performed to collect fluid from the abdomen. The following findings on fluid analysis strongly suggest SBP: total white blood cell count in the fluid greater than 500 cells/µL, total neutrophil count in the fluid greater than 250 cells/µL, lactate level in the fluid higher than 25 mg/dL, pH of the fluid below 7.35, and presence of bacteria on Gram-stain.

Patients with SBP should be admitted to the hospital and treated with broad-spectrum antibiotics. The preferred antibiotic is an intravenous third-generation cephalosporin, such as Ceftriaxone. If the patient is allergic to beta-lactam antibiotics, ciprofloxacin can be considered as an alternative. Administration of intravenous albumin has been shown to reduce the risk of kidney failure and death.

Respiratory alkalosis can be caused by hyperventilation, such as during periods of anxiety. It can also be a result of conditions like pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, or the early stages of aspirin overdose.

Respiratory acidosis is often associated with chronic obstructive pulmonary disease (COPD) or life-threatening asthma. Other causes include pulmonary edema, sedative drug overdose (such as opiates or benzodiazepines), neuromuscular disease, obesity, or certain medications.

Metabolic alkalosis can occur due to vomiting, potassium depletion (often caused by diuretic usage), Cushing’s syndrome, or Conn’s syndrome.

Metabolic acidosis with a raised anion gap can be caused by conditions like lactic acidosis (which can result from hypoxemia, shock, sepsis, or infarction) or ketoacidosis (commonly seen in diabetes, starvation, or alcohol excess). Other causes include renal failure or poisoning (such as late stages of aspirin overdose, methanol, or ethylene glycol).

Metabolic acidosis with a normal anion gap can be attributed to conditions like renal tubular acidosis, diarrhea, ammonium chloride ingestion, or adrenal insufficiency.

When administering CPR to a pregnant patient, it is important to make certain modifications. Firstly, the hand position for chest compressions should be adjusted to be 2-3 cm higher than usual. Additionally, the uterus should be manually displaced to the left in order to minimize compression on the inferior vena cava. If possible, a 15-30 degree left lateral tilt should be implemented. If resuscitation efforts do not result in the return of spontaneous circulation, it is advisable to seek urgent obstetric input for potential consideration of a C-section delivery. Lastly, when inserting an ET tube, it may be necessary to use a size that is 0.5-1.0mm smaller due to potential narrowing of the trachea caused by edema.

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.

The arterial line needle is inserted into the skin at an angle between 30 and 45 degrees. For a more detailed demonstration, please refer to the video provided in the media links section.

Further Reading:

Arterial line insertion is a procedure used to monitor arterial blood pressure continuously and obtain frequent blood gas samples. It is typically done when non-invasive blood pressure monitoring is not possible or when there is an anticipation of hemodynamic instability. The most common site for arterial line insertion is the radial artery, although other sites such as the ulnar, brachial, axillary, posterior tibial, femoral, and dorsalis pedis arteries can also be used.

The radial artery is preferred for arterial line insertion due to its superficial location, ease of identification and access, and lower complication rate compared to other sites. Before inserting the arterial line, it is important to perform Allen’s test to check for collateral circulation to the hand.

The procedure begins by identifying the artery by palpating the pulse at the wrist and confirming its position with doppler ultrasound if necessary. The wrist is then positioned dorsiflexed, and the skin is prepared and aseptic technique is maintained throughout the procedure. Local anesthesia is infiltrated at the insertion site, and the catheter needle is inserted at an angle of 30-45 degrees to the skin. Once flashback of pulsatile blood is seen, the catheter angle is flattened and advanced a few millimeters into the artery. Alternatively, a guide wire can be used with an over the wire technique.

After the catheter is advanced, the needle is withdrawn, and the catheter is connected to the transducer system and secured in place with sutures. It is important to be aware of absolute and relative contraindications to arterial line placement, as well as potential complications such as infection, thrombosis, hemorrhage, emboli, pseudo-aneurysm formation, AV fistula formation, arterial dissection, and nerve injury/compression.

Overall, arterial line insertion is a valuable procedure for continuous arterial blood pressure monitoring and frequent blood gas sampling, and the radial artery is the most commonly used site due to its accessibility and lower complication rate.

If the patient is suffering from adrenal insufficiency, it is likely that she will have hyponatremia and hyperkalemia. Adrenal insufficiency occurs when the adrenal glands do not produce enough hormones, particularly cortisol. This can lead to imbalances in electrolytes, such as sodium and potassium. Hyponatremia refers to low levels of sodium in the blood, while hyperkalemia refers to high levels of potassium in the blood. These abnormalities can cause symptoms such as dizziness, weakness, abdominal discomfort, and muscle aches. Additionally, the patient’s reported weight loss and other symptoms are consistent with adrenal insufficiency.

Further Reading:

Addison’s disease, also known as primary adrenal insufficiency or hypoadrenalism, is a rare disorder caused by the destruction of the adrenal cortex. This leads to reduced production of glucocorticoids, mineralocorticoids, and adrenal androgens. The deficiency of cortisol results in increased production of adrenocorticotropic hormone (ACTH) due to reduced negative feedback to the pituitary gland. This condition can cause metabolic disturbances such as hyperkalemia, hyponatremia, hypercalcemia, and hypoglycemia.

The symptoms of Addison’s disease can vary but commonly include fatigue, weight loss, muscle weakness, and low blood pressure. It is more common in women and typically affects individuals between the ages of 30-50. The most common cause of primary hypoadrenalism in developed countries is autoimmune destruction of the adrenal glands. Other causes include tuberculosis, adrenal metastases, meningococcal septicaemia, HIV, and genetic disorders.

The diagnosis of Addison’s disease is often suspected based on low cortisol levels and electrolyte abnormalities. The adrenocorticotropic hormone stimulation test is commonly used for confirmation. Other investigations may include adrenal autoantibodies, imaging scans, and genetic screening.

Addisonian crisis is a potentially life-threatening condition that occurs when there is an acute deficiency of cortisol and aldosterone. It can be the first presentation of undiagnosed Addison’s disease. Precipitating factors of an Addisonian crisis include infection, dehydration, surgery, trauma, physiological stress, pregnancy, hypoglycemia, and acute withdrawal of long-term steroids. Symptoms of an Addisonian crisis include malaise, fatigue, nausea or vomiting, abdominal pain, fever, muscle pains, dehydration, confusion, and loss of consciousness.

There is no fixed consensus on diagnostic criteria for an Addisonian crisis, as symptoms are non-specific. Investigations may include blood tests, blood gas analysis, and septic screens if infection is suspected. Management involves administering hydrocortisone and fluids. Hydrocortisone is given parenterally, and the dosage varies depending on the age of the patient. Fluid resuscitation with saline is necessary to correct any electrolyte disturbances and maintain blood pressure. The underlying cause of the crisis should also be identified and treated. Close monitoring of sodium levels is important to prevent complications such as osmotic demyelination syndrome.

The British Society of Gastroenterology (BSG) has developed guidelines for healthcare professionals who are assessing cases of acute lower intestinal bleeding in a hospital setting. These guidelines are particularly useful when determining which patients should be referred for further evaluation.

When patients present with lower gastrointestinal bleeding (LGIB), they should be categorized as either unstable or stable. Unstable patients are defined as those with a shock index greater than 1, which is calculated by dividing the heart rate by the systolic blood pressure (HR/SBP).

For stable patients, the next step is to determine whether their bleed is major (requiring hospitalization) or minor (suitable for outpatient management). This can be determined using a risk assessment tool called the Oakland risk score, which takes into account factors such as age, hemoglobin level, and findings from a digital rectal examination.

Patients with a minor self-limiting bleed (e.g., an Oakland score of less than 8 points) and no other indications for hospital admission can be discharged with urgent follow-up for further investigation as an outpatient.

Patients with a major bleed should be admitted to the hospital and scheduled for a colonoscopy as soon as possible.

If a patient is hemodynamically unstable or has a shock index greater than 1 even after initial resuscitation, and there is suspicion of active bleeding, a CT angiography (CTA) should be considered. This can be followed by endoscopic or radiological therapy.

If no bleeding source is identified by the initial CTA and the patient remains stable after resuscitation, an upper endoscopy should be performed immediately, as LGIB associated with hemodynamic instability may indicate an upper gastrointestinal bleeding source. Gastroscopy may be the first investigation if the patient stabilizes after initial resuscitation.

If indicated, catheter angiography with the possibility of embolization should be performed as soon as possible after a positive CTA to increase the chances of success. In centers with a 24/7 interventional radiology service, this procedure should be available within 60 minutes for hemodynamically unstable patients.

Emergency laparotomy should only be considered if all efforts to locate the bleeding using radiological and/or endoscopic methods have been exhausted, except in exceptional circumstances.

In some cases, red blood cell transfusion may be necessary. It is recommended to use restrictive blood transfusion thresholds, such as a hemoglobin trigger of 7 g/dL and a target of 7-9 g/d

The optic chiasm is situated just below the hypothalamus and is in close proximity to the pituitary gland. When the pituitary gland enlarges, it can impact the functioning of the optic nerve at this location. Specifically, the fibres from the nasal half of the retina cross over at the optic chiasm to form the optic tracts. Compression at the optic chiasm primarily affects these fibres, resulting in a visual defect that affects peripheral vision in both eyes, known as bitemporal hemianopia. There are several causes of optic chiasm lesions, with the most common being a pituitary tumor. Other causes include craniopharyngioma, meningioma, optic glioma, and internal carotid artery aneurysm. The diagram below provides a summary of the different visual field defects that can occur at various points in the visual pathway.

An overdose of aspirin often leads to a combination of respiratory alkalosis and metabolic acidosis. Initially, the stimulation of the respiratory center causes hyperventilation and results in respiratory alkalosis. However, as the overdose progresses, the direct acidic effects of aspirin cause an increase in the anion gap and metabolic acidosis.

Here is a summary of common causes for different acid-base disorders:

Respiratory alkalosis can be caused by hyperventilation due to factors such as anxiety, pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, and the early stages of aspirin overdose.

Respiratory acidosis can occur in individuals with chronic obstructive pulmonary disease (COPD), life-threatening asthma, pulmonary edema, sedative drug overdose (such as opioids or benzodiazepines), neuromuscular diseases, and obesity.

Metabolic alkalosis can be caused by vomiting, potassium depletion (often due to diuretic usage), Cushing’s syndrome, and Conn’s syndrome.

Metabolic acidosis with a raised anion gap can result from conditions such as lactic acidosis (caused by factors like hypoxemia, shock, sepsis, or tissue infarction), ketoacidosis (associated with diabetes, starvation, or excessive alcohol consumption), renal failure, and poisoning (including the late stages of aspirin overdose, methanol or ethylene glycol ingestion).

Metabolic acidosis with a normal anion gap can be seen in renal tubular acidosis, diarrhea, ammonium chloride ingestion, and adrenal insufficiency.

When dealing with an anaphylactic reaction, it is important to remove the trigger if it is easily accessible. However, it is not realistic to try and remove a peanut that has already been swallowed, and it is advised against attempting to induce vomiting in the patient.

In cases where an anaphylactic reaction has been confirmed, it is crucial to administer 500 micrograms of adrenaline immediately.

Femoral shaft fractures are quite common among children and have a significant impact on both the child and their family. It is important to carefully examine children with these fractures for any associated injuries, such as soft-tissue injury, head trauma, or additional fractures. In fact, up to 40% of children who experience a femoral shaft fracture due to high-energy trauma may have these associated injuries. Additionally, a thorough neurovascular examination should be conducted.

Rapidly immobilizing the limb is crucial for managing pain and limiting further blood loss from the fracture. For distal femoral shaft fractures, well-padded long leg splints with split plaster casts can be applied. However, for more proximal shaft fractures, long leg splints alone may not provide adequate control. In these cases, skin traction is a better option. Skin traction involves attaching a large foam pad to the patient’s lower leg using spray adhesive. A weight, approximately 10% of the child’s body weight, is then applied to the foam pad and allowed to hang over the foot of the bed. This constant longitudinal traction helps keep the bone fragments aligned.

When children experience severe pain, it is important to manage it aggressively yet safely. Immobilizing the fracture can provide significant relief. The Royal College of Emergency Medicine recommends other pain control measures for children, such as intranasal diamorphine (0.1 mg/kg in 0.2 ml sterile water), intravenous morphine (0.1-0.2 mg/kg), and oral analgesia (e.g., paracetamol 20 mg/kg, max 1 g, and ibuprofen 10 mg/kg, max 400 mg).

This patient is experiencing vaginal bleeding along with bradycardia and hypotension. These symptoms can be attributed to a condition known as cervical shock syndrome. It is likely that the products of conception (POC) are located within the os. In cervical shock syndrome, the cervix becomes dilated due to the presence of POC, leading to an increase in bleeding and triggering a vasovagal reaction.

To address this situation, it is crucial to conduct an urgent speculum examination. During this examination, the POC should be carefully removed using sterile sponge forceps.

Verapamil is a type of calcium-channel blocker that is commonly used to treat irregular heart rhythms and chest pain. It is important to note that verapamil should not be taken at the same time as beta-blockers like atenolol and bisoprolol. This is because when these medications are combined, they can have a negative impact on the heart’s ability to contract and the heart rate, leading to a significant drop in blood pressure, slow heart rate, impaired conduction between the upper and lower chambers of the heart, heart failure (due to decreased ability of the heart to pump effectively), and even a pause in the heart’s normal rhythm. For more information, you can refer to the section on verapamil interactions in the British National Formulary (BNF).

Adrenaline can be given in cases of life-threatening anaphylactic reactions, even if there are certain conditions that may make it less advisable. These conditions include coronary artery disease, uncontrolled hypertension, serious ventricular arrhythmias, and the second stage of labor. Despite these relative contraindications, adrenaline may still be administered to address the immediate danger posed by anaphylaxis.

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.

Bartter’s syndrome is a rare genetic defect that affects the ascending limb of the loop of Henle. This condition is characterized by low blood pressure and a hypokalemic alkalosis, which means there is a decrease in potassium levels in the blood.

Hyperkalemia, on the other hand, is defined as having a plasma potassium level greater than 5.5 mmol/L. There are various non-drug factors that can cause hyperkalemia, such as renal failure, excessive potassium supplementation, Addison’s disease (adrenal insufficiency), congenital adrenal hyperplasia, renal tubular acidosis (type 4), rhabdomyolysis, burns and trauma, and tumor lysis syndrome. Additionally, acidosis can also contribute to the development of hyperkalemia.

In addition to these non-drug causes, certain medications can also lead to hyperkalemia. These include ACE inhibitors, angiotensin receptor blockers, NSAIDs, beta-blockers, digoxin, and suxamethonium. It is important to be aware of these potential causes and to monitor potassium levels in order to prevent and manage hyperkalemia effectively.

Calcium-channel blocker overdose is a serious condition that should always be taken seriously as it can be potentially life-threatening. The two most dangerous types of calcium channel blockers in overdose are verapamil and diltiazem. These medications work by binding to the alpha-1 subunit of L-type calcium channels, which prevents the entry of calcium into the cells. These channels play a crucial role in the functioning of cardiac myocytes, vascular smooth muscle cells, and islet beta-cells.

Significant toxicity can occur with the ingestion of more than 10 tablets of verapamil (160 mg or 240 mg immediate or sustained-release capsules) or diltiazem (180 mg, 240 mg or 360 mg immediate or sustained-release capsules). In children, even 1-2 tablets of immediate or sustained-release verapamil or diltiazem can be harmful. Symptoms usually appear within 1-2 hours of taking standard preparations, but with slow-release versions, the onset of severe toxicity may be delayed by 12-16 hours, with peak effects occurring after 24 hours.

The main clinical manifestations of calcium-channel blocker overdose include nausea and vomiting, low blood pressure, slow heart rate and first-degree heart block, heart muscle ischemia and stroke, kidney failure, pulmonary edema, and high blood sugar levels.

When managing a patient with calcium-channel blocker overdose, certain bedside investigations are crucial. These include checking blood glucose levels, performing an electrocardiogram (ECG), and obtaining an arterial blood gas sample. Additional investigations that can provide helpful information include assessing urea and electrolyte levels, conducting a chest X-ray to check for pulmonary edema, and performing an echocardiography.

The current guidelines from NICE recommend that the first-line treatment for confirmed deep-vein thrombosis (DVT) or pulmonary embolus (PE) should be either apixaban or rivaroxaban, which are direct oral anticoagulants.

If neither of these options is suitable, the following alternatives should be considered:

1. LMWH (low molecular weight heparin) should be administered for at least 5 days, followed by dabigatran or edoxaban.

2. LMWH should be combined with a vitamin K antagonist (VKA), such as warfarin, for at least 5 days or until the international normalized ratio (INR) reaches at least 2.0 on 2 consecutive readings. Afterward, the VKA can be continued alone.

Mastoiditis occurs when a suppurative infection spreads from otitis media, affecting the middle ear, to the mastoid antrum. This infection causes inflammation in the mastoid and surrounding tissues, potentially leading to damage to the bone.

The mastoid antrum, also known as the tympanic antrum, is an air space located in the petrous part of the temporal bone. It connects to the mastoid cells at the back and the epitympanic recess through the aditus to the mastoid antrum.

The mastoid cells come in different types, varying in number and size. There are cellular cells with thin septa, diploeic cells that are marrow spaces with few air cells, and acellular cells that are neither cells nor marrow spaces.

These air spaces serve various functions, including acting as sound receptors, providing voice resonance, offering acoustic insulation and dissipation, protecting against physical damage, and reducing the weight of the cranium.

Overall, mastoiditis occurs when an infection from otitis media spreads to the mastoid antrum, causing inflammation and potential damage to the surrounding tissues and bone. The mastoid antrum and mastoid air cells within the temporal bone play important roles in sound reception, voice resonance, protection, and reducing cranial mass.

According to NICE, hyoscine butylbromide is recommended as the initial medication for managing nausea and vomiting in individuals with obstructive bowel disorders who are in the last days of life. NICE provides guidance on how to handle these symptoms in the final days of life, which includes assessing the potential causes of nausea and vomiting in the dying person. This may involve considering factors such as certain medications, recent chemotherapy or radiotherapy, psychological causes, biochemical causes like hypercalcemia, raised intracranial pressure, gastrointestinal motility disorder, ileus, or bowel obstruction.

It is important to discuss the available options for treating nausea and vomiting with the dying person and their loved ones. Non-pharmacological methods should also be considered when managing these symptoms in someone in the last days of life. When selecting medications for nausea and vomiting, factors such as the likely cause and reversibility of the symptoms, potential side effects (including sedation), other symptoms the person may be experiencing, and the desired balancing of effects when managing other symptoms should be taken into account. Additionally, compatibility and potential drug interactions with other medications the person is taking should be considered.

For individuals in the last days of life with obstructive bowel disorders who have nausea or vomiting, hyoscine butylbromide is recommended as the first-line pharmacological treatment. If the symptoms do not improve within 24 hours of starting treatment with hyoscine butylbromide, octreotide may be considered as an alternative option.

For more information, refer to the NICE guidance on the care of dying adults in the last days of life. https://www.nice.org.uk/guidance/ng31

To treat frostbite, it is important to quickly warm the affected area by immersing it in water that is consistently kept at a temperature of 40-42ºC. The Rewarming process should be continued until the affected area feels flexible and shows signs of redness, which typically takes around 15 to 30 minutes. It is recommended to provide strong pain relief medication during this process, as reperfusion can be extremely painful.

Further Reading:

Hypothermia is defined as a core temperature below 35ºC and can be graded as mild, moderate, severe, or profound based on the core temperature. When the core temperature drops, the basal metabolic rate decreases and cell signaling between neurons decreases, leading to reduced tissue perfusion. This can result in depressed myocardial contractility, vasoconstriction, ventilation-perfusion mismatch, and increased blood viscosity. Symptoms of hypothermia progress as the core temperature drops, starting with compensatory increases in heart rate and shivering, and eventually leading to bradyarrhythmias, prolonged PR, QRS, and QT intervals, and cardiac arrest.

In the management of hypothermic cardiac arrest, ALS should be initiated with some modifications. The pulse check during CPR should be prolonged to 1 minute due to difficulty in obtaining a pulse. Rewarming the patient is important, and mechanical ventilation may be necessary due to stiffness of the chest wall. Drug metabolism is slowed in hypothermic patients, so dosing of drugs should be adjusted or withheld. Electrolyte disturbances are common in hypothermic patients and should be corrected.

Frostbite refers to a freezing injury to human tissue and occurs when tissue temperature drops below 0ºC. It can be classified as superficial or deep, with superficial frostbite affecting the skin and subcutaneous tissues, and deep frostbite affecting bones, joints, and tendons. Frostbite can be classified from 1st to 4th degree based on the severity of the injury. Risk factors for frostbite include environmental factors such as cold weather exposure and medical factors such as peripheral vascular disease and diabetes.

Signs and symptoms of frostbite include skin changes, cold sensation or firmness to the affected area, stinging, burning, or numbness, clumsiness of the affected extremity, and excessive sweating, hyperemia, and tissue gangrene. Frostbite is diagnosed clinically and imaging may be used in some cases to assess perfusion or visualize occluded vessels. Management involves moving the patient to a warm environment, removing wet clothing, and rapidly rewarming the affected tissue. Analgesia should be given as reperfusion is painful, and blisters should be de-roofed and aloe vera applied. Compartment syndrome is a risk and should be monitored for. Severe cases may require surgical debridement of amputation.

The typical range for the partial pressure of carbon dioxide (pCO2) is 4.4-6.4 kilopascals (kPa). In terms of arterial blood gas (ABG) results, the normal range for pO2 (partial pressure of oxygen) is 10-14.4 kPa or 70-100 millimeters of mercury (mmHg). The normal range for pCO2 is 4.4-6.4 kPa or 35-45 mmHg. Additionally, the normal range for bicarbonate levels is 23-28 millimoles per liter (mmol/L).

Further Reading:

Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.

To reduce the risk of harm to the patient, it is important to test for collateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.

Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.

The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.

The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.

The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.

Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.

The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.

This patient is likely experiencing an acute coronary syndrome, possibly a non-ST-elevation myocardial infarction (NSTEMI) or unstable angina. The troponin test will help confirm the diagnosis. The patient’s ECG showed ST depression in the inferior leads, but this normalized after treatment with GTN and morphine, ruling out a ST-elevation myocardial infarction (STEMI).

Immediate pain relief should be provided. GTN (sublingual or buccal) can be used, but intravenous opioids like morphine should be considered, especially if a heart attack is suspected.

Aspirin should be given to all patients with unstable angina or NSTEMI as soon as possible and continued indefinitely, unless there are contraindications like bleeding risk or aspirin hypersensitivity. A loading dose of 300 mg should be administered right after presentation.

Fondaparinux should be given to patients without a high bleeding risk, unless coronary angiography is planned within 24 hours of admission. Unfractionated heparin can be an alternative to fondaparinux for patients who will undergo coronary angiography within 24 hours. For patients with significant renal impairment, unfractionated heparin can also be considered, with dose adjustment based on clotting function monitoring.

Routine administration of oxygen is no longer recommended, but oxygen saturation should be monitored using pulse oximetry as soon as possible, preferably before hospital admission. Supplemental oxygen should only be offered to individuals with oxygen saturation (SpO2) below 94% who are not at risk of hypercapnic respiratory failure, aiming for a SpO2 of 94-98%. For individuals with chronic obstructive pulmonary disease at risk of hypercapnic respiratory failure, a target SpO2 of 88-92% should be achieved until blood gas analysis is available.

Bivalirudin, a specific and reversible direct thrombin inhibitor (DTI), is recommended by NICE as a possible treatment for adults with STEMI undergoing percutaneous coronary intervention.

For more information, refer to the NICE guidelines on the assessment and diagnosis of chest pain of recent onset.

Conjunctivitis is the most common reason for red eyes, accounting for about 35% of all eye problems seen in general practice. It occurs when the conjunctiva, the thin layer covering the white part of the eye, becomes inflamed. Conjunctivitis can be caused by an infection or an allergic reaction.

Infective conjunctivitis is inflammation of the conjunctiva caused by a viral, bacterial, or parasitic infection. The most common type of infective conjunctivitis is viral, with adenoviruses being the main culprits. Bacterial conjunctivitis is also common and is usually caused by Streptococcus pneumoniae, Staphylococcus aureus, or Haemophilus influenzae.

The symptoms of infective conjunctivitis include sudden redness of the conjunctiva, discomfort described as a gritty or burning sensation, watering of the eyes, and discharge that may temporarily blurry vision. It can be challenging to differentiate between viral and bacterial conjunctivitis based on symptoms alone.

Here are some key features that can help distinguish between viral and bacterial conjunctivitis:

Features suggestive of viral conjunctivitis:
– Mild to moderate redness of the conjunctiva
– Presence of follicles on the inner surface of the eyelids
– Swelling of the eyelids
– Small, pinpoint bleeding under the conjunctiva
– Pseudomembranes (thin layers of tissue) may form on the inner surface of the eyelids in severe cases, often caused by adenovirus
– Less discharge (usually watery) compared to bacterial conjunctivitis
– Mild to moderate itching
– Symptoms of upper respiratory tract infection and swollen lymph nodes in front of the ears

Features suggestive of bacterial conjunctivitis:
– Purulent or mucopurulent discharge with crusting of the eyelids, which may cause them to stick together upon waking
– Mild or no itching
– Swollen lymph nodes in front of the ears, which are often present in severe bacterial conjunctivitis
– If the discharge is copious and mucopurulent, infection with Neisseria gonorrhoeae should be considered.

By considering these distinguishing features, healthcare professionals can better diagnose and manage cases of conjunctivitis.

An anal fissure is a tear in the wall of the anal mucosa that exposes the circular muscle layer. The majority of these tears occur in the posterior midline, and they are often caused by the passage of a large, hard stool after a period of constipation. If multiple fissures are present, it may indicate an underlying condition such as Crohn’s disease or tuberculosis.

Both men and women are equally affected by anal fissures, and they are most commonly seen in individuals in their thirties. The typical symptoms of an anal fissure include intense, sharp pain during bowel movements, which can last for up to an hour after passing stool. Additionally, there may be spots of bright red blood on the toilet paper when wiping, and a history of constipation.

The initial management approach for an anal fissure involves non-operative measures such as using stool softeners and bulking agents. To alleviate the intense anal pain, analgesics and topical local anesthetics may be prescribed. According to a recent meta-analysis, first-line therapy should involve the use of topical GTN or diltiazem, with botulinum toxin being used as a rescue treatment if necessary (Modern perspectives in the treatment of chronic anal fissures. Ann R Coll Surg Engl. 2007 Jul;89(5):472-8.)

Sphincterotomy, a surgical procedure, should be reserved for cases where the fissure does not heal with conservative measures. It has a success rate of 90%.

Nelson’s syndrome is a rare condition that occurs many years after a bilateral adrenalectomy for Cushing’s syndrome. It is believed to develop due to the loss of the normal negative feedback control that suppresses high cortisol levels. As a result, the hypothalamus starts producing CRH again, which stimulates the growth of a pituitary adenoma that produces adrenocorticotropic hormone (ACTH).

Only 15-20% of patients who undergo bilateral adrenalectomy will develop this condition, and it is now rarely seen as the procedure is no longer commonly performed.

The symptoms and signs of Nelson’s syndrome are related to the growth of the pituitary adenoma and the increased production of ACTH and melanocyte-stimulating hormone (MSH) from the adenoma. These may include headaches, visual field defects (up to 50% of cases), increased skin pigmentation, and the possibility of hypopituitarism.

ACTH levels will be significantly elevated (usually >500 ng/L). Thyroxine, TSH, gonadotrophin, and sex hormone levels may be low. Prolactin levels may be high, but not as high as with a prolactin-producing tumor. MRI or CT scanning can be helpful in identifying the presence of an expanding pituitary mass.

The treatment of choice for Nelson’s syndrome is trans-sphenoidal surgery.

Acute epiglottitis is a condition characterized by inflammation of the epiglottis. It can be life-threatening as it can completely block the airway, especially if not diagnosed promptly. In the past, the most common cause was Haemophilus influenzae type b (Hib), but with the widespread use of the Hib vaccine, it has become rare in children and is now more commonly seen in adults caused by Streptococcus spp like Streptococcus pyogenes and Streptococcus pneumonia. Other bacterial causes include Staphylococcus aureus, Pseudomonas spp, Moraxella catarrhalis, and Mycobacterium tuberculosis.

The typical symptoms of acute epiglottitis include fever, sore throat (initially resembling a viral sore throat), painful swallowing, difficulty swallowing secretions (seen as drooling in children), muffled voice (referred to as ‘hot potato’ voice), rapid heartbeat, tenderness in the front of the neck over the hyoid bone, cervical lymph node enlargement, and rapid deterioration in children.

To diagnose acute epiglottitis, the gold standard investigation is fibre-optic laryngoscopy, which allows direct visualization of the epiglottis. However, laryngoscopy should only be performed in settings prepared for intubation or tracheostomy in case upper airway obstruction occurs. If laryngoscopy is not possible, a lateral neck X-ray may be helpful, as it can show the characteristic ‘thumbprint sign’.

Management of acute epiglottitis usually involves conservative measures such as intravenous or oral antibiotics. However, in some cases, intubation may be necessary.

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.

Sexually transmitted eye infections can be quite severe and are often characterized by prolonged mucopurulent discharge. There are two main causes of these infections: Chlamydia trachomatis and Neisseria gonorrhoea. Differentiating between the two can be done by considering certain features.

Chlamydia trachomatis infection typically presents with chronic low-grade irritation and mucous discharge that lasts for more than two weeks in sexually active individuals. It may also be accompanied by pre-auricular lymphadenopathy. This type of infection is usually unilateral but can sometimes affect both eyes.

On the other hand, Neisseria gonorrhoea infection tends to develop rapidly, usually within 12 to 24 hours. It is characterized by copious mucopurulent discharge, eyelid swelling, and tender preauricular lymphadenopathy. This type of infection carries a higher risk of complications, such as uveitis, severe keratitis, and corneal perforation.

Based on the patient’s symptoms, it appears that they are more consistent with a Neisseria gonorrhoea infection. The rapid onset, copious discharge, and tender preauricular lymphadenopathy are indicative of this type of infection.

Treatment for gonococcal conjunctivitis in adults is typically based on limited research. However, a study has shown that all 12 patients responded well to a single 1 g intramuscular injection of ceftriaxone, along with a single episode of ocular lavage with saline.

In summary, sexually transmitted eye infections can be caused by either Chlamydia trachomatis or Neisseria gonorrhoea. Differentiating between the two is important in order to provide appropriate treatment. The patient in this case exhibits symptoms that align more closely with a Neisseria gonorrhoea infection, which carries a higher risk of complications. Treatment options for gonococcal conjunctivitis are limited, but a single injection of ceftriaxone has shown positive results in previous studies.