Inserting an IJV line on the right side of the neck is preferred because it reduces the risk of damaging the thoracic duct. The thoracic duct is where the largest lymphatic vessel in the body connects to the bloodstream. It is situated where the left subclavian and internal jugular veins meet, as well as the beginning of the brachiocephalic vein. Opting for the right side of the neck helps prevent potential harm to the thoracic duct.

Further Reading:

A central venous catheter (CVC) is a type of catheter that is inserted into a large vein in the body, typically in the neck, chest, or groin. It has several important uses, including CVP monitoring, pulmonary artery pressure monitoring, repeated blood sampling, IV access for large volumes of fluids or drugs, TPN administration, dialysis, pacing, and other procedures such as placement of IVC filters or venous stents.

When inserting a central line, it is ideal to use ultrasound guidance to ensure accurate placement. However, there are certain contraindications to central line insertion, including infection or injury to the planned access site, coagulopathy, thrombosis or stenosis of the intended vein, a combative patient, or raised intracranial pressure for jugular venous lines.

The most common approaches for central line insertion are the internal jugular, subclavian, femoral, and PICC (peripherally inserted central catheter) veins. The internal jugular vein is often chosen due to its proximity to the carotid artery, but variations in anatomy can occur. Ultrasound can be used to identify the vessels and guide catheter placement, with the IJV typically lying superficial and lateral to the carotid artery. Compression and Valsalva maneuvers can help distinguish between arterial and venous structures, and doppler color flow can highlight the direction of flow.

In terms of choosing a side for central line insertion, the right side is usually preferred to avoid the risk of injury to the thoracic duct and potential chylothorax. However, the left side can also be used depending on the clinical situation.

Femoral central lines are another option for central venous access, with the catheter being inserted into the femoral vein in the groin. Local anesthesia is typically used to establish a field block, with lidocaine being the most commonly used agent. Lidocaine works by blocking sodium channels and preventing the propagation of action potentials.

In summary, central venous catheters have various important uses and should ideally be inserted using ultrasound guidance. There are contraindications to their insertion, and different approaches can be used depending on the clinical situation. Local anesthesia is commonly used for central line insertion, with lidocaine being the preferred agent.

Theophylline, a medication commonly used to treat respiratory conditions, can be affected by certain drugs, either increasing or decreasing its plasma concentration and half-life. Drugs that can increase the plasma concentration of theophylline include calcium channel blockers like verapamil, cimetidine, fluconazole, macrolides such as erythromycin, methotrexate, and quinolones like ciprofloxacin. On the other hand, drugs like carbamazepine, phenobarbitol, phenytoin (and fosphenytoin), rifampicin, and St. John’s wort can decrease the plasma concentration of theophylline. It is important to be aware of these interactions when prescribing or taking theophylline to ensure its effectiveness and avoid potential side effects.

The first step in managing hypertension in patients with phaeochromocytoma is to use alpha blockade, usually with a medication called phenoxybenzamine. This is followed by beta blockade. Before undergoing surgery to remove the phaeochromocytoma, patients need to be on both alpha and beta blockers. Alpha blockade is typically achieved by giving phenoxybenzamine intravenously at a dose of 10-40 mg over one hour, and then switching to an oral form (10-60 mg/day in divided doses). It is important to start alpha blockade at least 7 to 10 days before surgery to allow for an increase in blood volume. Beta blockade is only considered once alpha blockade has been achieved, as starting beta blockers too soon can lead to a dangerous increase in blood pressure.

Further Reading:

Phaeochromocytoma is a rare neuroendocrine tumor that secretes catecholamines. It typically arises from chromaffin tissue in the adrenal medulla, but can also occur in extra-adrenal chromaffin tissue. The majority of cases are spontaneous and occur in individuals aged 40-50 years. However, up to 30% of cases are hereditary and associated with genetic mutations. About 10% of phaeochromocytomas are metastatic, with extra-adrenal tumors more likely to be metastatic.

The clinical features of phaeochromocytoma are a result of excessive catecholamine production. Symptoms are typically paroxysmal and include hypertension, headaches, palpitations, sweating, anxiety, tremor, abdominal and flank pain, and nausea. Catecholamines have various metabolic effects, including glycogenolysis, mobilization of free fatty acids, increased serum lactate, increased metabolic rate, increased myocardial force and rate of contraction, and decreased systemic vascular resistance.

Diagnosis of phaeochromocytoma involves measuring plasma and urine levels of metanephrines, catecholamines, and urine vanillylmandelic acid. Imaging studies such as abdominal CT or MRI are used to determine the location of the tumor. If these fail to find the site, a scan with metaiodobenzylguanidine (MIBG) labeled with radioactive iodine is performed. The highest sensitivity and specificity for diagnosis is achieved with plasma metanephrine assay.

The definitive treatment for phaeochromocytoma is surgery. However, before surgery, the patient must be stabilized with medical management. This typically involves alpha-blockade with medications such as phenoxybenzamine or phentolamine, followed by beta-blockade with medications like propranolol. Alpha blockade is started before beta blockade to allow for expansion of blood volume and to prevent a hypertensive crisis.

Patients with decompression illness should avoid taking analgesics as they can potentially harm the patient. Instead, oxygen is the preferred method of analgesia and has been shown to improve prognosis. Symptoms of decompression illness can often be resolved by simply breathing oxygen from a cylinder. It is important to note that Entonox should never be administered to patients with suspected decompression illness as the additional inert gas load from the nitrous oxide can worsen symptoms. NSAIDs should also be avoided as they can exacerbate micro-hemorrhages caused by decompression illness. In cases of decompression illness, patients will typically be treated with recompression in a hyperbaric oxygen chamber. However, it is important to be cautious with the use of oxygen as it can cause pulmonary and neurological toxicity at certain pressures. Therefore, there is a risk of oxygen toxicity developing in patients undergoing recompression, and opioids should be avoided as they are believed to increase this risk.

Further Reading:

Decompression illness (DCI) is a term that encompasses both decompression sickness (DCS) and arterial gas embolism (AGE). When diving underwater, the increasing pressure causes gases to become more soluble and reduces the size of gas bubbles. As a diver ascends, nitrogen can come out of solution and form gas bubbles, leading to decompression sickness or the bends. Boyle’s and Henry’s gas laws help explain the changes in gases during changing pressure.

Henry’s law states that the amount of gas that dissolves in a liquid is proportional to the partial pressure of the gas. Divers often use atmospheres (ATM) as a measure of pressure, with 1 ATM being the pressure at sea level. Boyle’s law states that the volume of gas is inversely proportional to the pressure. As pressure increases, volume decreases.

Decompression sickness occurs when nitrogen comes out of solution as a diver ascends. The evolved gas can physically damage tissue by stretching or tearing it as bubbles expand, or by provoking an inflammatory response. Joints and spinal nervous tissue are commonly affected. Symptoms of primary damage usually appear immediately or soon after a dive, while secondary damage may present hours or days later.

Arterial gas embolism occurs when nitrogen bubbles escape into the arterial circulation and cause distal ischemia. The consequences depend on where the embolism lodges, ranging from tissue ischemia to stroke if it lodges in the cerebral arterial circulation. Mechanisms for distal embolism include pulmonary barotrauma, right to left shunt, and pulmonary filter overload.

Clinical features of decompression illness vary, but symptoms often appear within six hours of a dive. These can include joint pain, neurological symptoms, chest pain or breathing difficulties, rash, vestibular problems, and constitutional symptoms. Factors that increase the risk of DCI include diving at greater depth, longer duration, multiple dives close together, problems with ascent, closed rebreather circuits, flying shortly after diving, exercise shortly after diving, dehydration, and alcohol use.

Diagnosis of DCI is clinical, and investigations depend on the presentation. All patients should receive high flow oxygen, and a low threshold for ordering a chest X-ray should be maintained. Hydration is important, and IV fluids may be necessary. Definitive treatment is recompression therapy in a hyperbaric oxygen chamber, which should be arranged as soon as possible. Entonox should not be given, as it will increase the pressure effect in air spaces.

Stab wounds to the abdomen result in tissue damage through laceration and cutting. When patients experience penetrating abdominal trauma due to stab wounds, the organs that are most commonly affected include the liver (40% of cases), small bowel (30% of cases), diaphragm (20% of cases), and colon (15% of cases). These statistics are derived from the latest edition of the ATLS manual.

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.

To control nosebleeds, it is recommended to have the patient sit upright with their upper body tilted forward and their mouth open. Apply firm pressure to the cartilaginous part of the nose, just in front of the bony septum, and hold it for 10-15 minutes without releasing the pressure.

Further Reading:

Epistaxis, or nosebleed, is a common condition that can occur in both children and older adults. It is classified as either anterior or posterior, depending on the location of the bleeding. Anterior epistaxis usually occurs in younger individuals and arises from the nostril, most commonly from an area called Little’s area. These bleeds are usually not severe and account for the majority of nosebleeds seen in hospitals. Posterior nosebleeds, on the other hand, occur in older patients with conditions such as hypertension and atherosclerosis. The bleeding in posterior nosebleeds is likely to come from both nostrils and originates from the superior or posterior parts of the nasal cavity or nasopharynx.

The management of epistaxis involves assessing the patient for signs of instability and implementing measures to control the bleeding. Initial measures include sitting the patient upright with their upper body tilted forward and their mouth open. Firmly pinching the cartilaginous part of the nose for 10-15 minutes without releasing the pressure can also help stop the bleeding. If these measures are successful, a cream called Naseptin or mupirocin nasal ointment can be prescribed for further treatment.

If bleeding persists after the initial measures, nasal cautery or nasal packing may be necessary. Nasal cautery involves using a silver nitrate stick to cauterize the bleeding point, while nasal packing involves inserting nasal tampons or inflatable nasal packs to stop the bleeding. In cases of posterior bleeding, posterior nasal packing or surgery to tie off the bleeding vessel may be considered.

Complications of epistaxis can include nasal bleeding, hypovolemia, anemia, aspiration, and even death. Complications specific to nasal packing include sinusitis, septal hematoma or abscess, pressure necrosis, toxic shock syndrome, and apneic episodes. Nasal cautery can lead to complications such as septal perforation and caustic injury to the surrounding skin.

In children under the age of 2 presenting with epistaxis, it is important to refer them for further investigation as an underlying cause is more likely in this age group.

Hyperkalaemia is a condition characterized by a high level of potassium in the blood, specifically a plasma potassium level greater than 5.5 mmol/l. It can be further classified into three categories based on the severity of the condition. Mild hyperkalaemia refers to a potassium level ranging from 5.5-5.9 mmol/l, while moderate hyperkalaemia is defined as a potassium level between 6.0-6.4 mmol/l. Severe hyperkalaemia is indicated by a potassium level exceeding 6.5 mmol/l.

The most common cause of hyperkalaemia in renal failure, which can occur either acutely or chronically. However, there are other factors that can contribute to this condition as well. These include acidosis, adrenal insufficiency, cell lysis, and excessive potassium intake.

Overall, hyperkalaemia is a medical condition that requires attention and management, as it can have significant implications for the body’s normal functioning.

Iodine deficiency is a widespread issue globally and is the leading cause of hypothyroidism worldwide. It is particularly prevalent in numerous African countries, as well as in developed nations such as Norway, Germany, Russia, and Ukraine. In the UK, however, autoimmune thyroiditis is the most common cause of hypothyroidism.

Further Reading:

The thyroid gland is an endocrine organ located in the anterior neck. It consists of two lobes connected by an isthmus. The gland produces hormones called thyroxine (T4) and triiodothyronine (T3), which regulate energy use, protein synthesis, and the body’s sensitivity to other hormones. The production of T4 and T3 is stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland, which is in turn stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.

Thyroid disorders can occur when there is an imbalance in the production or regulation of thyroid hormones. Hypothyroidism is characterized by a deficiency of thyroid hormones, while hyperthyroidism is characterized by an excess. The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. It is more common in women and is often associated with goiter. Other causes include subacute thyroiditis, atrophic thyroiditis, and iodine deficiency. On the other hand, the most common cause of hyperthyroidism is Graves’ disease, which is also an autoimmune disorder. Other causes include toxic multinodular goiter and subacute thyroiditis.

The symptoms and signs of thyroid disorders can vary depending on whether the thyroid gland is underactive or overactive. In hypothyroidism, common symptoms include weight gain, lethargy, cold intolerance, and dry skin. In hyperthyroidism, common symptoms include weight loss, restlessness, heat intolerance, and increased sweating. Both hypothyroidism and hyperthyroidism can also affect other systems in the body, such as the cardiovascular, gastrointestinal, and neurological systems.

Complications of thyroid disorders can include dyslipidemia, metabolic syndrome, coronary heart disease, heart failure, subfertility and infertility, impaired special senses, and myxedema coma in severe cases of hypothyroidism. In hyperthyroidism, complications can include Graves’ orbitopathy, compression of the esophagus or trachea by goiter, thyrotoxic periodic paralysis, arrhythmias, osteoporosis, mood disorders, and increased obstetric complications.

Myxedema coma is a rare and life-threatening complication of severe hypothyroidism. It can be triggered by factors such as infection or physiological insult and presents with lethargy, bradycardia, hypothermia, hypotension, hypoventilation, altered mental state, seizures and/or coma.

The MASCC Risk Index Score, developed by the Multinational Association of Supportive Care in Cancer, is a globally recognized scoring system that helps identify patients with neutropenic sepsis who have a low risk of complications and can potentially be treated as outpatients with early administration of antibiotics. This scoring system takes into account various characteristics to determine the risk level of the patient. These characteristics include the burden of febrile neutropenia with no or mild symptoms, absence of hypotension, no history of chronic obstructive pulmonary disease, presence of a solid tumor or hematological malignancy without previous fungal infection, absence of dehydration requiring parenteral fluids, burden of febrile neutropenia with moderate symptoms, being in an outpatient setting at the onset of fever, and age below 60 years. Each characteristic is assigned a certain number of points, and a total score of 21 or higher indicates a low risk, while a score below 21 indicates a high risk. The MASCC Risk Index Score has been validated internationally and has shown a positive predictive value of 91%, specificity of 68%, and sensitivity of 71%. For more detailed information, you can refer to the article titled Identifying Patients at Low Risk for FN Complications: Development and Validation of the MASCC Risk Index Score.

Viral induced wheeze is a common condition in childhood that is triggered by a viral infection, typically a cold. The wheezing occurs during the infection and can persist for several weeks after the infection has cleared. This condition is most commonly seen in children under the age of three, as their airways are smaller. It is also more prevalent in babies who were small for their gestational age and in children whose parents smoke. It is important to note that viral induced wheeze does not necessarily mean that the child has asthma, although a small percentage of children with this condition may go on to develop asthma. Asthma is more commonly seen in children with a family history of asthma or allergies. Inhalers are often prescribed for the management of viral induced wheeze, but they may not always be effective.

Warfarin has been found to heighten the likelihood of bleeding events when consumed alongside specific juices, such as cranberry juice and grapefruit juice. As a result, individuals who are taking warfarin should be cautioned against consuming these beverages. For more information on this topic, please refer to the BNF section on warfarin interactions and the interaction between warfarin and cranberry juice.

Epididymo-orchitis refers to the inflammation of the epididymis and/or testicle. It typically presents with sudden pain, swelling, and inflammation in the affected area. This condition can also occur chronically, which means that the pain and inflammation last for more than six months.

The causes of epididymo-orchitis vary depending on the age of the patient. In men under 35 years old, the infection is usually sexually transmitted and caused by Chlamydia trachomatis or Neisseria gonorrhoeae. In men over 35 years old, the infection is usually non-sexually transmitted and occurs as a result of enteric organisms that cause urinary tract infections, with Escherichia coli being the most common. However, there can be some overlap between these groups, so it is important to obtain a thorough sexual history in all age groups.

Mumps should also be considered as a potential cause of epididymo-orchitis in the 15 to 30 age group, as mumps orchitis occurs in around 40% of post-pubertal boys with mumps.

While most cases of epididymo-orchitis are infective, non-infectious causes can also occur. These include genito-urinary surgery, vasectomy, urinary catheterization, Behcet’s disease, sarcoidosis, and drug-induced cases such as those caused by amiodarone.

Patients with epididymo-orchitis typically present with unilateral scrotal pain and swelling that develops relatively quickly. The affected testis will be tender to touch, and there is usually a palpable swelling of the epididymis that starts at the lower pole of the testis and spreads towards the upper pole. The testis itself may also be involved, and there may be redness and/or swelling of the scrotum on the affected side. Patients may experience fever and urethral discharge as well.

The most important differential diagnosis to consider is testicular torsion, which requires immediate medical attention within 6 hours of onset to save the testicle. Testicular torsion is more likely in men under the age of 20, especially if the pain is very severe and sudden. It typically presents around four hours after onset. In this case, the patient’s age, longer history of symptoms, and the presence of fever are more indicative of epididymo-orchitis.

According to the latest guidelines from NICE, it is recommended that adult patients who are undergoing treatment for acute leukaemia, stem cell transplants, or solid tumours and are expected to experience significant neutropenia as a result of chemotherapy, should be offered prophylaxis with a fluoroquinolone such as ciprofloxacin (500 mg taken orally twice daily) during the period when neutropenia is expected. This is to help prevent the occurrence of neutropenic sepsis, a serious infection that can occur in cancer patients with low levels of neutrophils.

Reference:
NICE guidance: ‘Neutropenic sepsis: prevention and management of neutropenic sepsis in cancer patients’

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’s physiological parameters are mostly within normal range, but there is an increased pulse pressure and slight anxiety, suggesting a class I haemorrhage. It is crucial to be able to identify the degree of blood loss based on vital signs and mental status changes. 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 individual. In a 70 kg male patient, the total circulating blood volume is approximately five litres, which accounts for about 7% of their total body weight.

The ATLS haemorrhagic shock classification is as follows:

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

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

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

CLASS IV:
– Blood loss: More than 2000 mL
– Blood loss (% blood volume): More than 40%
– Pulse rate: Greater than 140 bpm
– Systolic BP: Decreased
– Pulse pressure: Decreased
– Respiratory rate: More than 40 breaths per minute
– Urine output: Negligible
– CNS/mental status: Confused, lethargic

Anaphylaxis is a severe and life-threatening hypersensitivity reaction that can have sudden onset and progression. It is characterized by skin or mucosal changes and can lead to life-threatening airway, breathing, or circulatory problems. Anaphylaxis can be allergic or non-allergic in nature.

In allergic anaphylaxis, there is an immediate hypersensitivity reaction where an antigen stimulates the production of IgE antibodies. These antibodies bind to mast cells and basophils. Upon re-exposure to the antigen, the IgE-covered cells release histamine and other inflammatory mediators, causing smooth muscle contraction and vasodilation.

Non-allergic anaphylaxis occurs when mast cells degrade due to a non-immune mediator. The clinical outcome is the same as in allergic anaphylaxis.

The management of anaphylaxis is the same regardless of the cause. Adrenaline is the most important drug and should be administered as soon as possible. The recommended doses for adrenaline vary based on age. Other treatments include high flow oxygen and an IV fluid challenge. Corticosteroids and chlorpheniramine are no longer recommended, while non-sedating antihistamines may be considered as third-line treatment after initial stabilization of airway, breathing, and circulation.

Common causes of anaphylaxis include food (such as nuts, which is the most common cause in children), drugs, and venom (such as wasp stings). Sometimes it can be challenging to determine if a patient had a true episode of anaphylaxis. In such cases, serum tryptase levels may be measured, as they remain elevated for up to 12 hours following an acute episode of anaphylaxis.

The Resuscitation Council (UK) provides guidelines for the management of anaphylaxis, including a visual algorithm that outlines the recommended steps for treatment.
https://www.resus.org.uk/sites/default/files/2021-05/Emergency%20Treatment%20of%20Anaphylaxis%20May%202021_0.pdf

The majority of dissections happen in individuals between the ages of 40 and 70, with the highest occurrence observed in the age group of 50 to 65.

Further Reading:

Aortic dissection is a life-threatening condition in which blood flows through a tear in the innermost layer of the aorta, creating a false lumen. Prompt treatment is necessary as the mortality rate increases by 1-2% per hour. There are different classifications of aortic dissection, with the majority of cases being proximal. Risk factors for aortic dissection include hypertension, atherosclerosis, connective tissue disorders, family history, and certain medical procedures.

The presentation of aortic dissection typically includes sudden onset sharp chest pain, often described as tearing or ripping. Back pain and abdominal pain are also common, and the pain may radiate to the neck and arms. The clinical picture can vary depending on which aortic branches are affected, and complications such as organ ischemia, limb ischemia, stroke, myocardial infarction, and cardiac tamponade may occur. Common signs and symptoms include a blood pressure differential between limbs, pulse deficit, and a diastolic murmur.

Various investigations can be done to diagnose aortic dissection, including ECG, CXR, and CT with arterial contrast enhancement (CTA). CT is the investigation of choice due to its accuracy in diagnosis and classification. Other imaging techniques such as transoesophageal echocardiography (TOE), magnetic resonance imaging/angiography (MRI/MRA), and digital subtraction angiography (DSA) are less commonly used.

Management of aortic dissection involves pain relief, resuscitation measures, blood pressure control, and referral to a vascular or cardiothoracic team. Opioid analgesia should be given for pain relief, and resuscitation measures such as high flow oxygen and large bore IV access should be performed. Blood pressure control is crucial, and medications such as labetalol may be used to reduce systolic blood pressure. Hypotension carries a poor prognosis and may require careful fluid resuscitation. Treatment options depend on the type of dissection, with type A dissections typically requiring urgent surgery and type B dissections managed by thoracic endovascular aortic repair (TEVAR) and blood pressure control optimization.

Public Health England (PHE) has a primary goal of promptly identifying potential disease outbreaks and epidemics. While accuracy of diagnosis is important, it is not the main focus. Since 1968, clinical suspicion of a notifiable infection has been sufficient for reporting.
Registered medical practitioners (RMPs) are legally obligated to notify the designated proper officer at their local council or local health protection team (HPT) if they suspect cases of certain infectious diseases.
The Health Protection (Notification) Regulations 2010 specify the diseases that RMPs must report to the proper officers at local authorities. These diseases include acute encephalitis, acute infectious hepatitis, acute meningitis, acute poliomyelitis, anthrax, botulism, brucellosis, cholera, COVID-19, diphtheria, enteric fever (typhoid or paratyphoid fever), food poisoning, haemolytic uraemic syndrome (HUS), infectious bloody diarrhoea, invasive group A streptococcal disease, Legionnaires’ disease, leprosy, malaria, measles, meningococcal septicaemia, mumps, plague, rabies, rubella, severe acute respiratory syndrome (SARS), scarlet fever, smallpox, tetanus, tuberculosis, typhus, viral haemorrhagic fever (VHF), whooping cough, and yellow fever. However, as of April 2010, ophthalmia neonatorum is no longer considered a notifiable disease in the UK.

Full thickness burns are devoid of pain as they result in the complete destruction of the superficial nerve endings. These burns usually display characteristics such as a lack of sensation, a coloration of the burnt skin in shades of white, brown, or black, a texture that is waxy or leathery, and a dry appearance without any blistering.

Further Reading:

Burn injuries can be classified based on their type (degree, partial thickness or full thickness), extent as a percentage of total body surface area (TBSA), and severity (minor, moderate, major/severe). Severe burns are defined as a >10% TBSA in a child and >15% TBSA in an adult.

When assessing a burn, it is important to consider airway injury, carbon monoxide poisoning, type of burn, extent of burn, special considerations, and fluid status. Special considerations may include head and neck burns, circumferential burns, thorax burns, electrical burns, hand burns, and burns to the genitalia.

Airway management is a priority in burn injuries. Inhalation of hot particles can cause damage to the respiratory epithelium and lead to airway compromise. Signs of inhalation injury include visible burns or erythema to the face, soot around the nostrils and mouth, burnt/singed nasal hairs, hoarse voice, wheeze or stridor, swollen tissues in the mouth or nostrils, and tachypnea and tachycardia. Supplemental oxygen should be provided, and endotracheal intubation may be necessary if there is airway obstruction or impending obstruction.

The initial management of a patient with burn injuries involves conserving body heat, covering burns with clean or sterile coverings, establishing IV access, providing pain relief, initiating fluid resuscitation, measuring urinary output with a catheter, maintaining nil by mouth status, closely monitoring vital signs and urine output, monitoring the airway, preparing for surgery if necessary, and administering medications.

Burns can be classified based on the depth of injury, ranging from simple erythema to full thickness burns that penetrate into subcutaneous tissue. The extent of a burn can be estimated using methods such as the rule of nines or the Lund and Browder chart, which takes into account age-specific body proportions.

Fluid management is crucial in burn injuries due to significant fluid losses. Evaporative fluid loss from burnt skin and increased permeability of blood vessels can lead to reduced intravascular volume and tissue perfusion. Fluid resuscitation should be aggressive in severe burns, while burns <15% in adults and <10% in children may not require immediate fluid resuscitation. The Parkland formula can be used to calculate the intravenous fluid requirements for someone with a significant burn injury.

The median nerve originates from the lateral and medial cords of the brachial plexus and receives contributions from the ventral roots of C5-C7 (lateral cord) and C8 and T1 (medial cord). It serves both motor and sensory functions.

In terms of motor function, the median nerve innervates the flexor muscles in the anterior compartment of the forearm, excluding the flexor carpi ulnaris and a portion of the flexor digitorum profundus, which are instead innervated by the ulnar nerve. Additionally, it innervates the thenar muscles and the lateral two lumbricals.

Regarding sensory function, the median nerve gives rise to the palmar cutaneous branch, which provides innervation to the lateral part of the palm. It also gives rise to the digital cutaneous branch, which innervates the lateral three and a half fingers on the palmar surface of the hand.

Within the forearm, the median nerve branches into two major branches. The first is the anterior interosseous nerve (AIN), which supplies the flexor pollicis longus, pronator quadratus, and the lateral half of the flexor digitorum profundus. The second is the palmar cutaneous branch, which provides sensory innervation to the skin of the radial palm.

Differentiating between damage to the median nerve at the elbow and wrist can be done by considering these two branches. Injury at the elbow affects these branches, while injury at the wrist spares them. It is important to note that the palmar cutaneous branch travels superficially to the flexor retinaculum and therefore remains functional in carpal tunnel syndrome. However, it can be damaged by laceration at the wrist.

A comparison of median nerve lesions at the wrist and elbow is presented below:

Median nerve at elbow:
– Motor loss: Weak wrist flexion and abduction, loss of thumb abduction and opposition, loss of flexion of index and middle fingers
– Sensory loss: Lateral 3 and ½ fingers and nail beds, lateral side of palm
– Hand deformity: Ulnar deviation of wrist, thenar wasting, papal benediction on flexing fingers

Median nerve at wrist:
– Motor loss: Loss of thumb abduction and opposition, wrist and finger flexion intact (due to intact AIN)
– Sensory loss: Lateral 3 and ½ fingers and nail beds, lateral side of palm (but can be preserved depending upon palmar cutaneous branch)
– Hand deformity: Thenar wasting, no ulnar deviation of wrist or papal benediction (due to intact AIN)

To remove contaminated material, it is recommended to remove and dispose of clothing. It is important to seal the clothing and treat it as hazardous waste. If wet decontamination is being utilized, patients should shower using warm water and detergent.

Further Reading:

Chemical incidents can occur as a result of leaks, spills, explosions, fires, terrorism, or the use of chemicals during wars. Industrial sites that use chemicals are required to conduct risk assessments and have accident plans in place for such incidents. Health services are responsible for decontamination, unless mass casualties are involved, and all acute health trusts must have major incident plans in place.

When responding to a chemical incident, hospitals prioritize containment of the incident and prevention of secondary contamination, triage with basic first aid, decontamination if not done at the scene, recognition and management of toxidromes (symptoms caused by exposure to specific toxins), appropriate supportive or antidotal treatment, transfer to definitive treatment, a safe end to the hospital response, and continuation of business after the event.

To obtain advice when dealing with chemical incidents, the two main bodies are Toxbase and the National Poisons Information Service. Signage on containers carrying chemicals and material safety data sheets (MSDS) accompanying chemicals also provide information on the chemical contents and their hazards.

Contamination in chemical incidents can occur in three phases: primary contamination from the initial incident, secondary contamination spread via contaminated people leaving the initial scene, and tertiary contamination spread to the environment, including becoming airborne and waterborne. The ideal personal protective equipment (PPE) for chemical incidents is an all-in-one chemical-resistant overall with integral head/visor and hands/feet worn with a mask, gloves, and boots.

Decontamination of contaminated individuals involves the removal and disposal of contaminated clothing, followed by either dry or wet decontamination. Dry decontamination is suitable for patients contaminated with non-caustic chemicals and involves blotting and rubbing exposed skin gently with dry absorbent material. Wet decontamination is suitable for patients contaminated with caustic chemicals and involves a warm water shower while cleaning the body with simple detergent.

After decontamination, the focus shifts to assessing the extent of any possible poisoning and managing it. The patient’s history should establish the chemical the patient was exposed to, the volume and concentration of the chemical, the route of exposure, any protective measures in place, and any treatment given. Most chemical poisonings require supportive care using standard resuscitation principles, while some chemicals have specific antidotes. Identifying toxidromes can be useful in guiding treatment, and specific antidotes may be administered accordingly.

The three sites most frequently used for IO access are the proximal tibia, distal tibia, and distal femur. The proximal tibia is located 2 cm below the tibial tuberosity, while the distal tibia is just above the medial malleolus. The distal femur site is situated 2 cm above the condyle in the midline. These sites are commonly chosen for IO access. However, there are also less commonly used sites such as the proximal humerus (above the surgical neck) and the iliac crest. It is important to note that the proximal humerus may be challenging to palpate in children and is typically not used in those under 5 years of age. Additionally, accessing the sternum requires a specialist device.

Further Reading:

Intraosseous (IO) cannulation is a technique used to gain urgent intravenous (IV) access in patients where traditional IV access is difficult to obtain. It involves injecting fluid or drugs directly into the medullary cavity of the bone. This procedure can be performed in both adult and pediatric patients and is commonly used in emergency situations.

There are different types of IO needles available, including manual IO needles and device-powered IO needles such as the EZ-IO. These tools allow healthcare professionals to access the bone and administer necessary medications or fluids quickly and efficiently.

The most commonly used sites for IO cannulation are the tibia (shinbone) and the femur (thighbone). In some cases, the proximal humerus (upper arm bone) may also be used. However, there are certain contraindications to IO cannulation that should be considered. These include fractures of the bone to be cannulated, overlying skin infections or a high risk of infection (such as burns), conditions like osteogenesis imperfecta or osteoporosis, ipsilateral vascular injury, and coagulopathy.

While IO cannulation is a valuable technique, there are potential complications that healthcare professionals should be aware of. These include superficial skin infections, osteomyelitis (infection of the bone), skin necrosis, growth plate injury (in pediatric patients), fractures, failure to access or position the needle correctly, extravasation (leakage of fluid or medication into surrounding tissues), and compartment syndrome (a rare but serious condition that can occur if there is an undiagnosed fracture).

Overall, IO cannulation is a useful method for gaining urgent IV access in patients when traditional methods are challenging. However, it is important for healthcare professionals to be aware of the potential complications and contraindications associated with this procedure.

This man is experiencing an acute episode of asthma. His initial peak flow measurement is 46% of his best, indicating a severe exacerbation. According to the BTS guidelines, acute asthma can be classified as moderate, acute severe, life-threatening, or near-fatal.

Moderate asthma is characterized by increasing symptoms and a peak expiratory flow rate (PEFR) between 50-75% of the individual’s best or predicted value. There are no signs of acute severe asthma in this case.

Acute severe asthma is identified by any one of the following criteria: a PEFR between 33-50% of the best or predicted value, a respiratory rate exceeding 25 breaths per minute, a heart rate over 110 beats per minute, or the inability to complete sentences in one breath.

Life-threatening asthma is indicated by any one of the following: a PEFR below 33% of the best or predicted value, oxygen saturation (SpO2) below 92%, arterial oxygen pressure (PaO2) below 8 kPa, normal arterial carbon dioxide pressure (PaCO2) between 4.6-6.0 kPa, a silent chest, cyanosis, poor respiratory effort, arrhythmia, exhaustion, altered conscious level, or hypotension.

Near-fatal asthma is characterized by elevated PaCO2 levels and/or the need for mechanical ventilation with increased inflation pressures.

Cauda equina syndrome (CES) is a rare but serious complication that can occur when a disc in the spine ruptures. This happens when the material from the disc is pushed into the spinal canal and puts pressure on a bundle of nerves in the lower back and sacrum. When this happens, it can lead to problems with controlling the bladder and bowels.

There are certain signs that may indicate the presence of CES, which are known as red flags. These include experiencing sciatica on both sides of the body, having a severe or worsening neurological deficit in both legs, such as significant weakness in the muscles that extend the knee, turn the ankle outward, or lift the foot upward. Other red flags include difficulty starting to urinate or a decreased sensation of the flow of urine, a loss of feeling when the rectum is full, a loss of sensation in the perianal, perineal, or genital areas (also known as saddle anesthesia or paresthesia), and a looseness in the anal sphincter muscle.

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.

Infantile hypertrophic pyloric stenosis is a condition characterized by the thickening and enlargement of the smooth muscle in the antrum of the stomach, leading to the narrowing of the pyloric canal. This narrowing can easily cause obstruction. It is a relatively common condition, occurring in about 1 in 500 live births, and is more frequently seen in males than females, with a ratio of 4 to 1. It is most commonly observed in first-born male children, although it can rarely occur in adults as well.

The main symptom of infantile hypertrophic pyloric stenosis is vomiting, which typically begins between 2 to 8 weeks of age. The vomit is usually non-bilious and forcefully expelled. It tends to occur around 30 to 60 minutes after feeding, leaving the baby hungry despite the vomiting. In some cases, there may be blood in the vomit. Other clinical features include persistent hunger, dehydration, weight loss, and constipation. An enlarged pylorus, often described as olive-shaped, can be felt in the right upper quadrant or epigastric in approximately 95% of cases. This is most noticeable at the beginning of a feed.

The typical acid-base disturbance seen in this condition is hypochloremic metabolic alkalosis. This occurs due to the loss of hydrogen and chloride ions in the vomit, as well as decreased secretion of pancreatic bicarbonate. The increased bicarbonate ions in the distal tubule of the kidney lead to the production of alkaline urine. Hyponatremia and hypokalemia are also commonly present.

Ultrasound scanning is the preferred diagnostic tool for infantile hypertrophic pyloric stenosis, as it is reliable and easy to perform. It has replaced barium studies as the investigation of choice.

Initial management involves fluid resuscitation, which should be tailored to the weight and degree of dehydration. Any electrolyte imbalances should also be corrected.

The definitive treatment for this condition is surgical intervention, with the Ramstedt pyloromyotomy being the procedure of choice. Laparoscopic pyloromyotomy is also an effective alternative if suitable facilities are available. The prognosis for infants with this condition is excellent, as long as there is no delay in diagnosis and treatment initiation.

According to NICE guidelines, amiodarone is recommended as the initial choice for pharmacological cardioversion of atrial fibrillation (AF) in individuals who have evidence of structural heart disease.

Further Reading:

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting around 5% of patients over the age of 70-75 years and 10% of patients aged 80-85 years. While AF can cause palpitations and inefficient cardiac function, the most important aspect of managing patients with AF is reducing the increased risk of stroke.

AF can be classified as first detected episode, paroxysmal, persistent, or permanent. First detected episode refers to the initial occurrence of AF, regardless of symptoms or duration. Paroxysmal AF occurs when a patient has 2 or more self-terminating episodes lasting less than 7 days. Persistent AF refers to episodes lasting more than 7 days that do not self-terminate. Permanent AF is continuous atrial fibrillation that cannot be cardioverted or if attempts to do so are deemed inappropriate. The treatment goals for permanent AF are rate control and anticoagulation if appropriate.

Symptoms of AF include palpitations, dyspnea, and chest pain. The most common sign is an irregularly irregular pulse. An electrocardiogram (ECG) is essential for diagnosing AF, as other conditions can also cause an irregular pulse.

Managing patients with AF involves two key parts: rate/rhythm control and reducing stroke risk. Rate control involves slowing down the irregular pulse to avoid negative effects on cardiac function. This is typically achieved using beta-blockers or rate-limiting calcium channel blockers. If one drug is not effective, combination therapy may be used. Rhythm control aims to restore and maintain normal sinus rhythm through pharmacological or electrical cardioversion. However, the majority of patients are managed with a rate control strategy.

Reducing stroke risk in patients with AF is crucial. Risk stratifying tools, such as the CHA2DS2-VASc score, are used to determine the most appropriate anticoagulation strategy. Anticoagulation is recommended for patients with a score of 2 or more. Clinicians can choose between warfarin and novel oral anticoagulants (NOACs) for anticoagulation.

Before starting anticoagulation, the patient’s bleeding risk should be assessed using tools like the HAS-BLED score or the ORBIT tool. These tools evaluate factors such as hypertension, abnormal renal or liver function, history of bleeding, age, and use of drugs that predispose to bleeding.

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.

Status epilepticus is a condition characterized by continuous seizure activity lasting for 5 minutes or more without the return of consciousness, or recurrent seizures (2 or more) without a period of neurological recovery in between. In such cases, it is important to address any low blood glucose levels urgently by administering intravenous glucose. While the patient may require additional antiepileptic drug (AED) therapy, the management of status epilepticus involves several general measures.

During the early stage of status epilepticus (0-10 minutes), the airway should be secured and resuscitation measures should be taken. Oxygen should be administered and the cardiorespiratory function should be assessed. It is also important to establish intravenous access. In the second stage (0-30 minutes), regular monitoring should be instituted and the possibility of non-epileptic status should be considered. Emergency AED therapy should be initiated and emergency investigations should be conducted. If there are indications of alcohol abuse or impaired nutrition, glucose and/or intravenous thiamine may be administered. Acidosis should be treated if severe.

In the third stage (0-60 minutes), the underlying cause of status epilepticus should be identified. The anaesthetist and intensive care unit (ITU) should be alerted. Any medical complications should be identified and treated, and pressor therapy may be considered if appropriate. In the fourth stage (30-90 minutes), the patient should be transferred to intensive care. Intensive care and EEG monitoring should be established, and intracranial pressure monitoring may be initiated if necessary. Initial long-term, maintenance AED therapy should also be initiated.

Emergency investigations for status epilepticus include blood tests for blood gases, glucose, renal and liver function, calcium and magnesium, full blood count (including platelets), blood clotting, and AED drug levels. Serum and urine samples should be saved for future analysis, including toxicology if the cause of the convulsive status epilepticus is uncertain. A chest radiograph may be taken to evaluate the possibility of aspiration. Additional investigations, such as brain imaging or lumbar puncture, may be conducted depending on the clinical circumstances.

Monitoring during the management of status epilepticus involves regular neurological observations and measurements of pulse, blood pressure, and temperature.