To prevent diffusion hypoxia, it is recommended to administer supplemental oxygen to patients for about 5 minutes after discontinuing nitrous oxide. This is important because there is a risk of developing diffusion hypoxia after the termination of nitrous oxide.

Further Reading:

Entonox® is a mixture of 50% nitrous oxide and 50% oxygen that can be used for self-administration to reduce anxiety. It can also be used alongside other anesthesia agents. However, its mechanism of action for anxiety reduction is not fully understood. The Entonox bottles are typically identified by blue and white color-coded collars, but a new standard will replace these with dark blue shoulders in the future. It is important to note that Entonox alone cannot be used as the sole maintenance agent in anesthesia.

One of the effects of nitrous oxide is the second-gas effect, where it speeds up the absorption of other inhaled anesthesia agents. Nitrous oxide enters the alveoli and diffuses into the blood, displacing nitrogen. This displacement causes the remaining alveolar gases to become more concentrated, increasing the fractional content of inhaled anesthesia gases and accelerating the uptake of volatile agents into the blood.

However, when nitrous oxide administration is stopped, it can cause diffusion hypoxia. Nitrous oxide exits the blood and diffuses back into the alveoli, while nitrogen diffuses in the opposite direction. Nitrous oxide enters the alveoli much faster than nitrogen leaves, resulting in the dilution of oxygen within the alveoli. This can lead to diffusion hypoxia, where the oxygen concentration in the alveoli is diluted, potentially causing oxygen deprivation in patients breathing air.

There are certain contraindications for using nitrous oxide, as it can expand in air-filled spaces. It should be avoided in conditions such as head injuries with intracranial air, pneumothorax, recent intraocular gas injection, and entrapped air following a recent underwater dive.

The clinical manifestations of theophylline toxicity are more closely associated with acute poisoning rather than chronic overexposure. The primary clinical features of theophylline toxicity include headache, dizziness, nausea and vomiting, abdominal pain, tachycardia and dysrhythmias, seizures, mild metabolic acidosis, hypokalaemia, hypomagnesaemia, hypophosphataemia, hypo- or hypercalcaemia, and hyperglycaemia. Seizures are more prevalent in cases of acute overdose compared to chronic overexposure. In contrast, chronic theophylline overdose typically presents with minimal gastrointestinal symptoms. Cardiac dysrhythmias are more frequently observed in individuals who have experienced chronic overdose rather than acute overdose.

C. difficile diarrhoea is typically diagnosed by testing a stool sample for the presence of its toxin using the cytotoxin assay. This patient has several risk factors for developing c.diff diarrhoea, including recent use of broad spectrum antibiotics, being over the age of 65, and residing in a nursing home. The gold standard for diagnosing c.diff diarrhoea is the detection of exotoxin in the stool using the cytotoxin assay. The C13 urea breath test is used to detect h.pylori infection, while stool antigen testing is commonly used to detect h.pylori as well as rotavirus and other viral causes of gastroenteritis. Stool microscopy is utilized to identify the presence of parasitic organisms such as protozoa and helminths.

Further Reading:

Clostridium difficile (C.diff) is a gram positive rod commonly found in hospitals. Some strains of C.diff produce exotoxins that can cause intestinal damage, leading to pseudomembranous colitis. This infection can range from mild diarrhea to severe illness. Antibiotic-associated diarrhea is often caused by C.diff, with 20-30% of cases being attributed to this bacteria. Antibiotics such as clindamycin, cephalosporins, fluoroquinolones, and broad-spectrum penicillins are frequently associated with C.diff infection.

Clinical features of C.diff infection include diarrhea, distinctive smell, abdominal pain, raised white blood cell count, and in severe cases, toxic megacolon. In some severe cases, diarrhea may be absent due to the infection causing paralytic ileus. Diagnosis is made by detecting Clostridium difficile toxin (CDT) in the stool. There are two types of exotoxins produced by C.diff, toxin A and toxin B, which cause mucosal damage and the formation of a pseudomembrane in the colon.

Risk factors for developing C.diff infection include age over 65, antibiotic treatment, previous C.diff infection, exposure to infected individuals, proton pump inhibitor or H2 receptor antagonist use, prolonged hospitalization or residence in a nursing home, and chronic disease or immunosuppression. Complications of C.diff infection can include toxic megacolon, colon perforation, sepsis, and even death, especially in frail elderly individuals.

Management of C.diff infection involves stopping the causative antibiotic if possible, optimizing hydration with IV fluids if necessary, and assessing the severity of the infection. Treatment options vary based on severity, ranging from no antibiotics for mild cases to vancomycin or fidaxomicin for moderate cases, and hospital protocol antibiotics (such as oral vancomycin with IV metronidazole) for severe or life-threatening cases. Severe cases may require admission under gastroenterology or GI surgeons.

Pyloric stenosis is characterized by recurring episodes of projectile vomiting and the presence of a mass in the upper abdomen, often described as an olive. This patient exhibits clinical features that align with pyloric stenosis and possesses several common risk factors, including being a male, being the firstborn son, being bottle-fed, and being delivered via C-section. It is important to note that intestinal atresia is typically diagnosed either during pregnancy or shortly after birth.

Further Reading:

Pyloric stenosis is a condition that primarily affects infants, characterized by the thickening of the muscles in the pylorus, leading to obstruction of the gastric outlet. It typically presents between the 3rd and 12th weeks of life, with recurrent projectile vomiting being the main symptom. The condition is more common in males, with a positive family history and being first-born being additional risk factors. Bottle-fed children and those delivered by c-section are also more likely to develop pyloric stenosis.

Clinical features of pyloric stenosis include projectile vomiting, usually occurring about 30 minutes after a feed, as well as constipation and dehydration. A palpable mass in the upper abdomen, often described as like an olive, may also be present. The persistent vomiting can lead to electrolyte disturbances, such as hypochloremia, alkalosis, and mild hypokalemia.

Ultrasound is the preferred diagnostic tool for confirming pyloric stenosis. It can reveal specific criteria, including a pyloric muscle thickness greater than 3 mm, a pylorus longitudinal length greater than 15-17 mm, a pyloric volume greater than 1.5 cm3, and a pyloric transverse diameter greater than 13 mm.

The definitive treatment for pyloric stenosis is pyloromyotomy, a surgical procedure that involves making an incision in the thickened pyloric muscle to relieve the obstruction. Before surgery, it is important to correct any hypovolemia and electrolyte disturbances with intravenous fluids. Overall, pyloric stenosis is a relatively common condition in infants, but with prompt diagnosis and appropriate management, it can be effectively treated.

Traumatic aortic rupture, also known as traumatic aortic disruption or transection, occurs when the aorta is torn or ruptured due to physical trauma. This condition often leads to sudden death because of severe bleeding. Motor vehicle accidents and falls from great heights are the most common causes of this injury.

The patients with the highest chances of survival are those who have an incomplete tear near the ligamentum arteriosum of the proximal descending aorta, close to where the left subclavian artery branches off. The presence of an intact adventitial layer or contained mediastinal hematoma helps maintain continuity and prevents immediate bleeding and death. If promptly identified and treated, survivors of these injuries can recover. In cases where traumatic aortic rupture leads to sudden death, approximately 50% of patients have damage at the aortic isthmus, while around 15% have damage in either the ascending aorta or the aortic arch.

Initial chest X-rays may show signs consistent with a traumatic aortic injury. However, false-positive and false-negative results can occur, and sometimes there may be no abnormalities visible on the X-ray. Some of the possible X-ray findings include a widened mediastinum, hazy left lung field, obliteration of the aortic knob, fractures of the 1st and 2nd ribs, deviation of the trachea to the right, presence of a pleural cap, elevation and rightward shift of the right mainstem bronchus, depression of the left mainstem bronchus, obliteration of the space between the pulmonary artery and aorta, and deviation of the esophagus or NG tube to the right.

A helical contrast-enhanced CT scan of the chest is the preferred initial investigation for suspected blunt aortic injury. It has proven to be highly accurate, with close to 100% sensitivity and specificity. CT scanning should be performed liberally, as chest X-ray findings can be unreliable. However, hemodynamically unstable patients should not be placed in a CT scanner. If the CT results are inconclusive, aortography or trans-oesophageal echo can be performed for further evaluation.

Immediate surgical intervention is necessary for these injuries. Endovascular repair is the most common method used and has excellent short-term outcomes. Open repair may also be performed depending on the circumstances. It is important to control heart rate and blood pressure during stabilization to reduce the risk of rupture. Pain should be managed with appropriate analgesic

The primary treatment for paracetamol overdose is acetylcysteine. Acetylcysteine is an extremely effective antidote, but its effectiveness decreases quickly if administered more than a few hours after a significant ingestion. Ingestions that exceed 75 mg/kg are considered to be significant.

For patients who decline treatment, methionine is a helpful alternative. It is taken orally in a dosage of 2.5 g every 4 hours, with a total dose of 10 g.

A needle cricothyroidotomy is a procedure used in emergency situations to provide oxygenation when intubation and oxygenation are not possible. It is typically performed when a patient cannot be intubated or oxygenated. There are certain conditions that make this procedure contraindicated, such as local infection, distorted anatomy, previous failed attempts, and swelling or mass lesions.

To perform a needle cricothyroidotomy, the necessary equipment should be assembled and prepared. The patient should be positioned supine with their neck in a neutral position. The neck should be cleaned in a sterile manner using antiseptic swabs. If time allows, the area should be anesthetized locally. A 12 or 14 gauge over-the-needle catheter should be assembled to a 10 mL syringe.

The cricothyroid membrane, located between the thyroid and cricoid cartilage, should be identified anteriorly. The trachea should be stabilized with the thumb and forefinger of one hand. Using the other hand, the skin should be punctured in the midline with the needle over the cricothyroid membrane. The needle should be directed at a 45° angle caudally while negative pressure is applied to the syringe. Needle aspiration should be maintained as the needle is inserted through the lower half of the cricothyroid membrane, with air aspiration indicating entry into the tracheal lumen.

Once the needle is in place, the syringe and needle should be removed while the catheter is advanced to the hub. The oxygen catheter should be attached and the airway secured. It is important to be aware of possible complications, such as technique failure, cannula obstruction or dislodgement, injury to local structures, and surgical emphysema if high flow oxygen is administered through a malpositioned cannula.

Benzodiazepines are commonly used in the UK to manage symptoms of alcohol withdrawal. Currently, only diazepam and chlordiazepoxide have been authorized for this purpose. Other benzodiazepines like alprazolam, clobazam, and lorazepam do not currently have authorization for treating alcohol withdrawal symptoms in the UK.

Carbamazepine is also used in the UK to manage alcohol-related withdrawal symptoms, but it does not have official authorization for this use.

Clomethiazole, on the other hand, does have UK marketing authorization for treating alcohol withdrawal symptoms, but it is only recommended for use in a hospital setting with close supervision. The product information for clomethiazole advises caution when prescribing it to individuals with a history of addiction or outpatient alcoholics. It is also not recommended for patients who continue to drink or abuse alcohol. Combining alcohol with clomethiazole, especially in alcoholics with cirrhosis, can lead to fatal respiratory depression even with short-term use. Therefore, clomethiazole should only be used in a hospital under close supervision or, in rare cases, by specialist units on an outpatient basis with careful monitoring of the daily dosage.

Slapped cheek syndrome, also known as fifth disease or erythema infectiosum, is caused by parvovirus B19. It is most commonly seen in children aged 4-12, but can affect individuals of any age. In the UK, the peak occurrence of this condition is in April and May. Slapped cheek syndrome is contagious, with the period of infectivity occurring before the appearance of the characteristic rash. The rash itself is painless.

Diagnosing slapped cheek syndrome is typically based on clinical presentation, characterized by the sudden onset of bright red cheeks resembling a slap mark. In some cases, a faint rash may also appear on other parts of the body. The rash usually lasts for a few days, but in rare instances, it may persist for a few weeks. Treatment for this condition is usually focused on managing symptoms. Additional symptoms that may accompany the rash include a mild fever and joint pain.

While slapped cheek syndrome is generally mild and resolves on its own, certain groups of individuals require extra caution. Pregnant women, for instance, are at an increased risk of miscarriage if exposed to fifth disease. Patients with sickle cell disease or weakened immune systems also need to take extra precautions.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur. One common adverse reaction is febrile transfusion reactions, which present as an unexpected rise in temperature during or after transfusion. This can be caused by cytokine accumulation or recipient antibodies reacting to donor antigens. Treatment for febrile transfusion reactions is supportive, and other potential causes should be ruled out.

Another serious complication is acute haemolytic reaction, which is often caused by ABO incompatibility due to administration errors. This reaction requires the transfusion to be stopped and IV fluids to be administered. Delayed haemolytic reactions can occur several days after a transfusion and may require monitoring and treatment for anaemia and renal function. Allergic reactions, TRALI (Transfusion Related Acute Lung Injury), TACO (Transfusion Associated Circulatory Overload), and GVHD (Graft-vs-Host Disease) are other potential complications that require specific management approaches.

In summary, blood transfusion carries risks and potential complications, but efforts have been made to improve safety procedures. It is important to be aware of these complications and to promptly address any adverse reactions that may occur during or after a transfusion.

The ulnar nerve provides innervation to several muscles in the hand. These include the palmar interossei, dorsal interossei, medial two lumbricals, and abductor digiti minimi. On the other hand, the median nerve innervates the opponens pollicis, lateral two lumbricals, and flexor pollicis brevis. Lastly, the radial nerve is responsible for innervating the extensor digitorum muscle.

Addison’s disease, a condition characterized by insufficient production of hormones by the adrenal glands, has different causes depending on the geographical location. Tuberculosis is the leading cause of Addison’s disease globally, while autoimmune adrenalitis is the most common cause in developed countries like the UK.

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.

Individuals who have chickenpox should refrain from coming into contact with others for a minimum of 5 days starting from when the rash first appears and continuing until all blisters have formed a crust.

Further Reading:

Chickenpox is caused by the varicella zoster virus (VZV) and is highly infectious. It is spread through droplets in the air, primarily through respiratory routes. It can also be caught from someone with shingles. The infectivity period lasts from 4 days before the rash appears until 5 days after the rash first appeared. The incubation period is typically 10-21 days.

Clinical features of chickenpox include mild symptoms that are self-limiting. However, older children and adults may experience more severe symptoms. The infection usually starts with a fever and is followed by an itchy rash that begins on the head and trunk before spreading. The rash starts as macular, then becomes papular, and finally vesicular. Systemic upset is usually mild.

Management of chickenpox is typically supportive. Measures such as keeping cool and trimming nails can help alleviate symptoms. Calamine lotion can be used to soothe the rash. People with chickenpox should avoid contact with others for at least 5 days from the onset of the rash until all blisters have crusted over. Immunocompromised patients and newborns with peripartum exposure should receive varicella zoster immunoglobulin (VZIG). If chickenpox develops, IV aciclovir should be considered. Aciclovir may be prescribed for immunocompetent, non-pregnant adults or adolescents with severe chickenpox or those at increased risk of complications. However, it is not recommended for otherwise healthy children with uncomplicated chickenpox.

Complications of chickenpox can include secondary bacterial infection of the lesions, pneumonia, encephalitis, disseminated haemorrhagic chickenpox, and rare conditions such as arthritis, nephritis, and pancreatitis.

Shingles is the reactivation of the varicella zoster virus that remains dormant in the nervous system after primary infection with chickenpox. It typically presents with signs of nerve irritation before the eruption of a rash within the dermatomal distribution of the affected nerve. Patients may feel unwell with malaise, myalgia, headache, and fever prior to the rash appearing. The rash appears as erythema with small vesicles that may keep forming for up to 7 days. It usually takes 2-3 weeks for the rash to resolve.

Management of shingles involves keeping the vesicles covered and dry to prevent secondary bacterial infection.

This ECG indicates changes that are consistent with an acute inferoposterior myocardial infarction (MI). There is ST elevation in leads I, II, aVF, and V6, along with reciprocal ST depression in leads V1-V4 and aVR. Additionally, there are tall dominant R waves in leads V2-V3 and upright T waves in leads V2-V3. Based on these findings, the most likely vessel involved in this case is the right coronary artery.

To summarize the vessels involved in different types of myocardial infarction see below:
ECG Leads – Location of MI | Vessel involved
V1-V3 – Anteroseptal | Left anterior descending
V3-V4 – Anterior | Left anterior descending
V5-V6 – Anterolateral | Left anterior descending / left circumflex artery
V1-V6 – Extensive anterior | Left anterior descending
I, II, aVL, V6 – Lateral | Left circumflex artery
II, III, aVF – Inferior | Right coronary artery (80%), Left circumflex artery (20%)
V1, V4R – Right ventricle | Right coronary artery
V7-V9 – Posterior | Right coronary artery

According to NICE guidelines, when treating a campylobacter infection, clarithromycin is recommended as the first choice of antibiotic. Antibiotics are typically only prescribed for individuals with severe symptoms, such as a high fever, bloody or frequent diarrhea, or for those who have a weakened immune system, like this patient who has diabetes. NICE advises a dosage of clarithromycin 250-500 mg taken twice daily for a duration of 5-7 days. It is best to start treatment within 3 days of the onset of illness.

Further Reading:

Campylobacter jejuni is a common cause of gastrointestinal infections, particularly travellers diarrhoea. It is a gram-negative bacterium that appears as curved rods. The infection is transmitted through the feco-oral route, often through the ingestion of contaminated meat, especially poultry. The incubation period for Campylobacter jejuni is typically 1-7 days, and the illness usually lasts for about a week.

The main symptoms of Campylobacter jejuni infection include watery, and sometimes bloody, diarrhea accompanied by abdominal cramps, fever, malaise, and headache. In some cases, complications can arise from the infection. Guillain-Barre syndrome (GBS) is one such complication that is associated with Campylobacter jejuni. Approximately 30% of GBS cases are caused by this bacterium.

When managing Campylobacter jejuni infection, conservative measures are usually sufficient, with a focus on maintaining hydration. However, in cases where symptoms are severe, such as high fever, bloody diarrhea, or high-output diarrhea, or if the person is immunocompromised, antibiotics may be necessary. NICE recommends the use of clarithromycin, administered at a dose of 250-500 mg twice daily for 5-7 days, starting within 3 days of the onset of illness.

Corneal microdeposits are found in almost all individuals (over 90%) who have been taking amiodarone for more than six months, particularly at doses higher than 400 mg/day. These deposits generally do not cause any symptoms, although approximately 10% of patients may experience a perception of a ‘bluish halo’ around objects they see.

Amiodarone can also have other effects on the eye, but these are much less common, occurring in only 1-2% of patients. These effects include optic neuropathy, nonarteritic anterior ischemic optic neuropathy (N-AION), optic disc swelling, and visual field defects.

Lung protective ventilation is a strategy that involves using smaller amounts of air during each breath (low tidal volumes) and restricting the maximum pressure applied during inhalation (plateau pressure). This approach also allows for a certain level of increased carbon dioxide levels in the body (hypercapnia).

Further Reading:

Mechanical ventilation is the use of artificial means to assist or replace spontaneous breathing. It can be invasive, involving instrumentation inside the trachea, or non-invasive, where there is no instrumentation of the trachea. Non-invasive mechanical ventilation (NIV) in the emergency department typically refers to the use of CPAP or BiPAP.

CPAP, or continuous positive airways pressure, involves delivering air or oxygen through a tight-fitting face mask to maintain a continuous positive pressure throughout the patient’s respiratory cycle. This helps maintain small airway patency, improves oxygenation, decreases airway resistance, and reduces the work of breathing. CPAP is mainly used for acute cardiogenic pulmonary edema.

BiPAP, or biphasic positive airways pressure, also provides positive airway pressure but with variations during the respiratory cycle. The pressure is higher during inspiration than expiration, generating a tidal volume that assists ventilation. BiPAP is mainly indicated for type 2 respiratory failure in patients with COPD who are already on maximal medical therapy.

The pressure settings for CPAP typically start at 5 cmH2O and can be increased to a maximum of 15 cmH2O. For BiPAP, the starting pressure for expiratory pressure (EPAP) or positive end-expiratory pressure (PEEP) is 3-5 cmH2O, while the starting pressure for inspiratory pressure (IPAP) is 10-15 cmH2O. These pressures can be titrated up if there is persisting hypoxia or acidosis.

In terms of lung protective ventilation, low tidal volumes of 5-8 ml/kg are used to prevent atelectasis and reduce the risk of lung injury. Inspiratory pressures (plateau pressure) should be kept below 30 cm of water, and permissible hypercapnia may be allowed. However, there are contraindications to lung protective ventilation, such as unacceptable levels of hypercapnia, acidosis, and hypoxemia.

Overall, mechanical ventilation, whether invasive or non-invasive, is used in various respiratory and non-respiratory conditions to support or replace spontaneous breathing and improve oxygenation and ventilation.

Aortic dissection is a condition that occurs when the middle layer of the aorta, known as the tunica media, becomes weakened. This weakening leads to the development of cases of aortic dissection.

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.

The ECG shows the following findings:
– There is ST depression in leads V1-V4 and aVR.
– There is ST elevation in leads V5-V6, II, III, and aVF.
– There is a positive R wave in leads V1 and V2, which indicates a reverse Q wave.
These ECG changes indicate that there is an acute inferoposterior myocardial infarction.

This patient has experienced otic barotrauma, which is most commonly seen during aircraft descent but can also occur in divers. Otic barotrauma occurs when the eustachian tube fails to equalize the pressure between the middle ear and the atmosphere, resulting in a pressure difference. This is more likely to happen in patients with eustachian tube dysfunction, such as those with acute otitis media or glue ear.

Patients with otic barotrauma often complain of severe ear pain, conductive hearing loss, ringing in the ears (tinnitus), and dizziness (vertigo). Upon examination, fluid can be observed behind the eardrum, and in more severe cases, the eardrum may even rupture.

In most instances, the symptoms of otic barotrauma resolve within a few days without any treatment. However, in more severe cases, it may take 2-3 weeks for the symptoms to subside. Nasal decongestants can be beneficial before and during a flight, but their effectiveness is limited once symptoms have already developed. Nasal steroids have no role in the management of otic barotrauma, and antibiotics should only be used if an infection develops.

The most appropriate course of action in this case would be to provide the patient with an explanation of what has occurred and reassure them that their symptoms should improve soon.

Pneumonia in newborns is typically caused by organisms that inhabit the mother’s genital tract. Despite the widespread use of chemoprophylaxis to prevent maternal carriage, Group B haemolytic Streptococcus remains a common culprit in early-onset infections in full-term and near-term infants aged less than three days. Among very low birth weight infants, Escherichia Coli is the most frequently encountered bacterial strain. Additionally, neonatal pneumonia can be caused by other bacteria such as Chlamydia trachomatis, Listeria monocytogenes, and Haemophilus influenzae.

The ratio of chest compressions to ventilations is 15:2. This ratio has not been proven through experiments, but it has been validated through mathematical studies. When performing chest compressions on a child, it is recommended to make them at least 1/3 of the depth of the child’s chest. Additionally, the optimal compression rate is between 100 and 120 compressions per minute.
To protect the airway of an unconscious child, the oropharyngeal (Guedel) airway is the best option. However, it should not be used on awake patients as there is a risk of vomiting and aspiration.
In children, asystole is the most common arrest rhythm. This occurs when the young heart responds to prolonged hypoxia and acidosis by progressively slowing down, eventually resulting in asystole.

In the UK, peptic ulcer disease is the leading cause of upper gastrointestinal bleeding. It surpasses all other listed causes combined in terms of prevalence.

Further Reading:

Upper gastrointestinal bleeding (UGIB) refers to the loss of blood from the gastrointestinal tract, occurring in the upper part of the digestive system. It can present as haematemesis (vomiting blood), coffee-ground emesis, bright red blood in the nasogastric tube, or melaena (black, tarry stools). UGIB can lead to significant hemodynamic compromise and is a major health burden, accounting for approximately 70,000 hospital admissions each year in the UK with a mortality rate of 10%.

The causes of UGIB vary, with peptic ulcer disease being the most common cause, followed by gastritis/erosions, esophagitis, and other less common causes such as varices, Mallory Weiss tears, and malignancy. Swift assessment, hemodynamic resuscitation, and appropriate interventions are essential for the management of UGIB.

Assessment of patients with UGIB should follow an ABCDE approach, and scoring systems such as the Glasgow-Blatchford bleeding score (GBS) and the Rockall score are recommended to risk stratify patients and determine the urgency of endoscopy. Transfusion may be necessary for patients with massive hemorrhage, and platelet transfusion, fresh frozen plasma (FFP), and prothrombin complex concentrate may be offered based on specific criteria.

Endoscopy plays a crucial role in the management of UGIB. Unstable patients with severe acute UGIB should undergo endoscopy immediately after resuscitation, while all other patients should undergo endoscopy within 24 hours of admission. Endoscopic treatment of non-variceal bleeding may involve mechanical methods of hemostasis, thermal coagulation, or the use of fibrin or thrombin with adrenaline. Proton pump inhibitors should only be used after endoscopy.

Variceal bleeding requires specific management, including the use of terlipressin and prophylactic antibiotics. Oesophageal varices can be treated with band ligation or transjugular intrahepatic portosystemic shunts (TIPS), while gastric varices may be treated with endoscopic injection of N-butyl-2-cyanoacrylate or TIPS if bleeding is not controlled.

For patients taking NSAIDs, aspirin, or clopidogrel, low-dose aspirin can be continued once hemostasis is achieved, NSAIDs should be stopped in patients presenting with UGIB.

Central retinal vein occlusion (CRVO) is a condition that usually leads to painless, one-sided vision loss. When examining the retina, it may appear similar to a ‘pizza thrown against a wall’, with swollen retinal veins, swelling of the optic disc, numerous flame-shaped hemorrhages, and cotton wool spots. Hypertension is present in about 65% of CRVO cases and is more common in individuals aged 65 and above.

On the other hand, branch retinal vein occlusion (BRVO) typically affects only one section of the retina, resulting in visual field deficits in that specific quadrant rather than complete vision loss.

These situations are uncommon, but it is crucial to have a plan in place for dealing with them when they arise. This emphasizes the importance of having strong history taking skills and the ability to problem-solve.

Based on the information available, it appears that the patient may have ingested a significant amount of paracetamol, putting them at risk of toxic effects. It would be helpful to have a calm conversation with the patient to understand their perspective, as they may have a fear of needles and may not want any blood tests done.

If there are any family members or a next of kin present, it might be worth giving them some time with the patient to see if they can persuade them to change their mind. If none of these approaches are successful, it is necessary to assess the patient’s mental capacity to make the decision to decline treatment. It is important to remember that capacity can vary depending on the situation and decision at hand.

If it is determined that the patient lacks the capacity to make the decision to decline treatment, there may be a possibility of providing care against their expressed wishes. In such cases, it is advisable to involve the mental health team to formally assess for evidence of mental illness. This assessment may strengthen the case for the patient to be sectioned, which would allow certain actions to be taken against their wishes, including treating them for the effects of their mental illness, which in this case includes addressing the overdose.

Conscious sedation involves a patient who can respond purposefully to verbal commands. It is different from deeper levels of sedation where the patient may only respond to painful stimuli or not respond at all. In conscious sedation, the patient can usually maintain their own airway and does not need assistance with breathing or cardiovascular support.

Further Reading:

Procedural sedation is commonly used by emergency department (ED) doctors to minimize pain and discomfort during procedures that may be painful or distressing for patients. Effective procedural sedation requires the administration of analgesia, anxiolysis, sedation, and amnesia. This is typically achieved through the use of a combination of short-acting analgesics and sedatives.

There are different levels of sedation, ranging from minimal sedation (anxiolysis) to general anesthesia. It is important for clinicians to understand the level of sedation being used and to be able to manage any unintended deeper levels of sedation that may occur. Deeper levels of sedation are similar to general anesthesia and require the same level of care and monitoring.

Various drugs can be used for procedural sedation, including propofol, midazolam, ketamine, and fentanyl. Each of these drugs has its own mechanism of action and side effects. Propofol is commonly used for sedation, amnesia, and induction and maintenance of general anesthesia. Midazolam is a benzodiazepine that enhances the effect of GABA on the GABA A receptors. Ketamine is an NMDA receptor antagonist and is used for dissociative sedation. Fentanyl is a highly potent opioid used for analgesia and sedation.

The doses of these drugs for procedural sedation in the ED vary depending on the drug and the route of administration. It is important for clinicians to be familiar with the appropriate doses and onset and peak effect times for each drug.

Safe sedation requires certain requirements, including appropriate staffing levels, competencies of the sedating practitioner, location and facilities, and monitoring. The level of sedation being used determines the specific requirements for safe sedation.

After the procedure, patients should be monitored until they meet the criteria for safe discharge. This includes returning to their baseline level of consciousness, having vital signs within normal limits, and not experiencing compromised respiratory status. Pain and discomfort should also be addressed before discharge.

Acute closed-angle glaucoma is a serious eye condition that requires immediate medical attention. It occurs when the iris pushes forward and blocks the fluid from reaching the trabecular meshwork, which is responsible for draining the eye. This blockage leads to increased pressure inside the eye and can cause damage to the optic nerve.

The main symptoms of acute closed-angle glaucoma include severe eye pain, vision loss or decreased visual acuity, redness and congestion around the cornea, swelling of the cornea, a fixed semi-dilated pupil, and nausea and vomiting. Some individuals may also experience episodes of blurred vision or seeing haloes before the onset of these symptoms.

On the other hand, chronic open-angle glaucoma is a more common form of the condition. It affects about 1 in 50 people over the age of 40 and 1 in 10 people over the age of 75. In this type of glaucoma, there is a partial blockage in the trabecular meshwork, which gradually restricts the drainage of fluid from the eye. As a result, the pressure inside the eye gradually increases, leading to optic nerve damage. Unlike acute closed-angle glaucoma, chronic open-angle glaucoma does not cause eye pain or redness. Instead, it presents slowly with a gradual loss of peripheral vision, while central vision is relatively preserved.

It is important to seek medical attention if you experience any symptoms of glaucoma, as early diagnosis and treatment can help prevent further vision loss.

The BTS guidelines for acute asthma in children recommend administering oral steroids early in the treatment of asthma attacks. It is advised to give a dose of 20 mg prednisolone for children aged 2–5 years and a dose of 30–40 mg for children over 5 years old. If a child is already taking maintenance steroid tablets, they should receive 2 mg/kg prednisolone, up to a maximum dose of 60 mg. If a child vomits after taking the medication, the dose of prednisolone should be repeated. In cases where a child is unable to keep down orally ingested medication, intravenous steroids should be considered. Typically, treatment for up to three days is sufficient, but the duration of the course should be adjusted based on the time needed for recovery. Tapering off the medication is not necessary unless the steroid course exceeds 14 days. For more information, refer to the BTS/SIGN Guideline on the Management of Asthma.

A needle cricothyroidotomy is a procedure used in emergency situations to provide oxygenation when intubation and oxygenation are not possible. It is typically performed when a patient cannot be intubated or oxygenated. There are certain conditions that make this procedure contraindicated, such as local infection, distorted anatomy, previous failed attempts, and swelling or mass lesions.

To perform a needle cricothyroidotomy, the necessary equipment should be assembled and prepared. The patient should be positioned supine with their neck in a neutral position. The neck should be cleaned in a sterile manner using antiseptic swabs. If time allows, the area should be anesthetized locally. A 12 or 14 gauge over-the-needle catheter should be assembled to a 10 mL syringe.

The cricothyroid membrane, located between the thyroid and cricoid cartilage, should be identified anteriorly. The trachea should be stabilized with the thumb and forefinger of one hand. Using the other hand, the skin should be punctured in the midline with the needle over the cricothyroid membrane. The needle should be directed at a 45° angle caudally while negative pressure is applied to the syringe. Needle aspiration should be maintained as the needle is inserted through the lower half of the cricothyroid membrane, with air aspiration indicating entry into the tracheal lumen.

Once the needle is in place, the syringe and needle should be removed while the catheter is advanced to the hub. The oxygen catheter should be attached and the airway secured. It is important to be aware of possible complications, such as technique failure, cannula obstruction or dislodgement, injury to local structures, and surgical emphysema if high flow oxygen is administered through a malpositioned cannula.

Ipratropium bromide is a medication that falls under the category of antimuscarinic drugs. It is commonly used to manage acute asthma and chronic obstructive pulmonary disease (COPD). While it can provide short-term relief for chronic asthma, it is generally recommended to use short-acting β2 agonists as they act more quickly and are preferred.

According to the guidelines set by the British Thoracic Society (BTS), nebulized ipratropium bromide (0.5 mg every 4-6 hours) can be added to β2 agonist treatment for patients with acute severe or life-threatening asthma, or those who do not respond well to initial β2 agonist therapy.

For mild cases of chronic obstructive pulmonary disease, aerosol inhalation of ipratropium can be used for short-term relief, as long as the patient is not already using a long-acting antimuscarinic drug like tiotropium. The maximum effect of ipratropium occurs within 30-60 minutes after use, and its bronchodilating effects can last for 3-6 hours. Typically, treatment with ipratropium is recommended three times a day to maintain bronchodilation.

The most common side effect of ipratropium bromide is dry mouth. Other potential side effects include constipation, cough, paroxysmal bronchospasm, headache, nausea, and palpitations. It is important to note that ipratropium can cause urinary retention in patients with prostatic hyperplasia and bladder outflow obstruction. Additionally, it can trigger acute closed-angle glaucoma in susceptible patients.

For more information on the management of asthma, it is recommended to refer to the BTS/SIGN Guideline on the Management of Asthma.