Salicylate poisoning initially leads to respiratory alkalosis, followed by metabolic acidosis. Salicylates, like aspirin, stimulate the respiratory center in the medulla, causing hyperventilation and respiratory alkalosis. This is usually the first acid-base imbalance observed in salicylate poisoning. As aspirin is metabolized, it disrupts oxidative phosphorylation in the mitochondria, leading to an increase in lactate levels due to anaerobic metabolism. The accumulation of lactic acid and acidic metabolites then causes metabolic acidosis.

Further Reading:

Salicylate poisoning, particularly from aspirin overdose, is a common cause of poisoning in the UK. One important concept to understand is that salicylate overdose leads to a combination of respiratory alkalosis and metabolic acidosis. Initially, the overdose stimulates the respiratory center, leading to hyperventilation and respiratory alkalosis. However, as the effects of salicylate on lactic acid production, breakdown into acidic metabolites, and acute renal injury occur, it can result in high anion gap metabolic acidosis.

The clinical features of salicylate poisoning include hyperventilation, tinnitus, lethargy, sweating, pyrexia (fever), nausea/vomiting, hyperglycemia and hypoglycemia, seizures, and coma.

When investigating salicylate poisoning, it is important to measure salicylate levels in the blood. The sample should be taken at least 2 hours after ingestion for symptomatic patients or 4 hours for asymptomatic patients. The measurement should be repeated every 2-3 hours until the levels start to decrease. Other investigations include arterial blood gas analysis, electrolyte levels (U&Es), complete blood count (FBC), coagulation studies (raised INR/PTR), urinary pH, and blood glucose levels.

To manage salicylate poisoning, an ABC approach should be followed to ensure a patent airway and adequate ventilation. Activated charcoal can be administered if the patient presents within 1 hour of ingestion. Oral or intravenous fluids should be given to optimize intravascular volume. Hypokalemia and hypoglycemia should be corrected. Urinary alkalinization with intravenous sodium bicarbonate can enhance the elimination of aspirin in the urine. In severe cases, hemodialysis may be necessary.

Urinary alkalinization involves targeting a urinary pH of 7.5-8.5 and checking it hourly. It is important to monitor for hypokalemia as alkalinization can cause potassium to shift from plasma into cells. Potassium levels should be checked every 1-2 hours.

In cases where the salicylate concentration is high (above 500 mg/L in adults or 350 mg/L in children), sodium bicarbonate can be administered intravenously. Hemodialysis is the treatment of choice for severe poisoning and may be indicated in cases of high salicylate levels, resistant metabolic acidosis, acute kidney injury, pulmonary edema, seizures and coma.

Patients who have bacterial tracheitis usually do not show any improvement when treated with steroids and adrenaline nebulizers. The symptoms of bacterial tracheitis include a prelude of upper respiratory tract infection symptoms, followed by a rapid decline in health with the presence of stridor and difficulty breathing. Despite treatment with steroids and adrenaline, there is no improvement in the patient’s condition. On the other hand, patients with epiglottitis commonly experience difficulty swallowing and excessive saliva production.

Further Reading:

Croup, also known as laryngotracheobronchitis, is a respiratory infection that primarily affects infants and toddlers. It is characterized by a barking cough and can cause stridor (a high-pitched sound during breathing) and respiratory distress due to swelling of the larynx and excessive secretions. The majority of cases are caused by parainfluenza viruses 1 and 3. Croup is most common in children between 6 months and 3 years of age and tends to occur more frequently in the autumn.

The clinical features of croup include a barking cough that is worse at night, preceded by symptoms of an upper respiratory tract infection such as cough, runny nose, and congestion. Stridor, respiratory distress, and fever may also be present. The severity of croup can be graded using the NICE system, which categorizes it as mild, moderate, severe, or impending respiratory failure based on the presence of symptoms such as cough, stridor, sternal/intercostal recession, agitation, lethargy, and decreased level of consciousness. The Westley croup score is another commonly used tool to assess the severity of croup based on the presence of stridor, retractions, air entry, oxygen saturation levels, and level of consciousness.

In cases of severe croup with significant airway obstruction and impending respiratory failure, symptoms may include a minimal barking cough, harder-to-hear stridor, chest wall recession, fatigue, pallor or cyanosis, decreased level of consciousness, and tachycardia. A respiratory rate over 70 breaths per minute is also indicative of severe respiratory distress.

Children with moderate or severe croup, as well as those with certain risk factors such as chronic lung disease, congenital heart disease, neuromuscular disorders, immunodeficiency, age under 3 months, inadequate fluid intake, concerns about care at home, or high fever or a toxic appearance, should be admitted to the hospital. The mainstay of treatment for croup is corticosteroids, which are typically given orally. If the child is too unwell to take oral medication, inhaled budesonide or intramuscular dexamethasone may be used as alternatives. Severe cases may require high-flow oxygen and nebulized adrenaline.

When considering the differential diagnosis for acute stridor and breathing difficulty, non-infective causes such as inhaled foreign bodies

Posterior epistaxis, which is bleeding from the back of the nose, is typically caused by bleeding from the sphenopalatine artery or its branches. The most common surgical treatment for posterior epistaxis involves tying off the sphenopalatine artery. It is important to note that there is some disagreement in the literature regarding the exact location of the bleeding, with some sources referring to Woodruff’s plexus. However, cadaveric studies suggest that Woodruff’s plexus is more likely a venous anastomosis rather than an arterial one involving branches of the sphenopalatine artery.

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.

If a person has symptoms or signs that indicate diabetes, a random venous plasma glucose concentration of 11.1 mmol/l or higher is considered to be indicative of diabetes mellitus. However, it is important to note that a diagnosis should not be made based solely on one test. A second test should be conducted to confirm the diagnosis. It is also worth mentioning that temporary high blood sugar levels may occur in individuals who are experiencing acute infection, trauma, circulatory issues, or other forms of stress that are not related to diabetes.

Further Reading:

Diabetes Mellitus:
– Definition: a group of metabolic disorders characterized by persistent hyperglycemia caused by deficient insulin secretion, resistance to insulin, or both.
– Types: Type 1 diabetes (absolute insulin deficiency), Type 2 diabetes (insulin resistance and relative insulin deficiency), Gestational diabetes (develops during pregnancy), Other specific types (monogenic diabetes, diabetes secondary to pancreatic or endocrine disorders, diabetes secondary to drug treatment).
– Diagnosis: Type 1 diabetes diagnosed based on clinical grounds in adults presenting with hyperglycemia. Type 2 diabetes diagnosed in patients with persistent hyperglycemia and presence of symptoms or signs of diabetes.
– Risk factors for type 2 diabetes: obesity, inactivity, family history, ethnicity, history of gestational diabetes, certain drugs, polycystic ovary syndrome, metabolic syndrome, low birth weight.

Hypoglycemia:
– Definition: lower than normal blood glucose concentration.
– Diagnosis: defined by Whipple’s triad (signs and symptoms of low blood glucose, low blood plasma glucose concentration, relief of symptoms after correcting low blood glucose).
– Blood glucose level for hypoglycemia: NICE defines it as <3.5 mmol/L, but there is inconsistency across the literature.
– Signs and symptoms: adrenergic or autonomic symptoms (sweating, hunger, tremor), neuroglycopenic symptoms (confusion, coma, convulsions), non-specific symptoms (headache, nausea).
– Treatment options: oral carbohydrate, buccal glucose gel, glucagon, dextrose. Treatment should be followed by re-checking glucose levels.

Treatment of neonatal hypoglycemia:
– Treat with glucose IV infusion 10% given at a rate of 5 mL/kg/hour.
– Initial stat dose of 2 mL/kg over five minutes may be required for severe hypoglycemia.
– Mild asymptomatic persistent hypoglycemia may respond to a single dose of glucagon.
– If hypoglycemia is caused by an oral anti-diabetic drug, the patient should be admitted and ongoing glucose infusion or other therapies may be required.

Note: Patients who have a hypoglycemic episode with a loss of warning symptoms should not drive and should inform the DVLA.

When treating men for uncomplicated urinary tract infections (UTIs), a 7-day course of antibiotics is typically recommended. Unlike women, men are advised to take a longer course of antibiotics, with a preference for 7 days instead of 3. The National Institute for Health and Care Excellence (NICE) suggests the following as the first-line treatment, although local microbiology departments may make adjustments based on antibiotic resistance patterns: Trimethoprim 200 mg taken twice daily for 7 days, or Nitrofurantoin 100 mg (modified-release) taken twice daily for 7 days. If prostatitis is suspected, a quinolone antibiotic like ciprofloxacin may be used, and treatment duration is usually 2-4 weeks.

Further Reading:

A urinary tract infection (UTI) is an infection that occurs in any part of the urinary system, from the kidneys to the bladder. It is characterized by symptoms such as dysuria, nocturia, polyuria, urgency, incontinence, and changes in urine appearance and odor. UTIs can be classified as lower UTIs, which affect the bladder, or upper UTIs, which involve the kidneys. Recurrent UTIs can be due to relapse or re-infection, and the number of recurrences considered significant depends on age and sex. Uncomplicated UTIs occur in individuals with a normal urinary tract and kidney function, while complicated UTIs are caused by anatomical, functional, or pharmacological factors that make the infection persistent, recurrent, or resistant to treatment.

The most common cause of UTIs is Escherichia coli, accounting for 70-95% of cases. Other causative organisms include Staphylococcus saprophyticus, Proteus mirabilis, and Klebsiella species. UTIs are typically caused by bacteria from the gastrointestinal tract entering the urinary tract through the urethra. Other less common mechanisms of entry include direct spread via the bloodstream or instrumentation of the urinary tract, such as catheter insertion.

Diagnosis of UTIs involves urine dipstick testing and urine culture. A urine culture should be sent in certain circumstances, such as in male patients, pregnant patients, women aged 65 years or older, patients with persistent or unresolved symptoms, recurrent UTIs, patients with urinary catheters, and those with risk factors for resistance or complicated UTIs. Further investigations, such as cystoscopy and imaging, may be required in cases of recurrent UTIs or suspected underlying causes.

Management of UTIs includes simple analgesia, advice on adequate fluid intake, and the prescription of appropriate antibiotics. The choice of antibiotic depends on the patient’s gender and risk factors. For women, first-line antibiotics include nitrofurantoin or trimethoprim, while second-line options include nitrofurantoin (if not used as first-line), pivmecillinam, or fosfomycin. For men, trimethoprim or nitrofurantoin are the recommended antibiotics. In cases of suspected acute prostatitis, fluoroquinolone antibiotics such as ciprofloxacin or ofloxacin may be prescribed for a 4-week course.

Enterotoxigenic E.coli is a strain that does not invade the body and does not lead to inflammation or bloody diarrhea. On the other hand, enterogenic strains result in excessive watery diarrhea and are typically not accompanied by abdominal cramping.

There are several infectious causes of bloody diarrhea, including Campylobacter spp., Shigella spp., Salmonella spp., Clostridium difficile, Enterohaemorrhagic Escherichia coli, Yersinia spp., Schistosomiasis, and Amoebiasis (Entamoeba histolytica).

A 512 Hz tuning fork is recommended for conducting both the Rinne’s and Weber’s tests. However, a lower-pitched 128 Hz tuning fork is commonly used to assess vibration sense during a peripheral nervous system examination. Although a 256 Hz tuning fork can be used for both tests, it is considered less reliable.

To perform the Weber’s test, the 512 Hz tuning fork should be set in motion and then placed on the center of the patient’s forehead. The patient should be asked if they perceive the sound in the middle of their forehead or if it is heard more on one side.

If the sound is heard more on one side, it may indicate either ipsilateral conductive hearing loss or contralateral sensorineural hearing loss.

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.

Blood transfusion is a crucial 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 has been an improvement in safety procedures and a reduction in transfusion use, errors and serious adverse reactions still occur and often go unreported.

Mild allergic reactions during blood transfusion are relatively common and typically occur within a few minutes of starting the transfusion. These reactions happen when patients have antibodies that react with foreign plasma proteins in the transfused blood components. Symptoms of mild allergic reactions include urticaria, Pruritus, and hives.

Anaphylaxis, on the other hand, is much rarer and occurs when an individual has previously been sensitized to an allergen present in the blood. When re-exposed to the allergen, the body releases IgE or IgG antibodies, leading to severe symptoms such as bronchospasm, laryngospasm, abdominal pain, nausea, vomiting, hypotension, shock, and loss of consciousness. Anaphylaxis can be fatal.

Mild allergic reactions can be managed by slowing down the transfusion rate and administering antihistamines. If there is no progression after 30 minutes, the transfusion may continue. Patients who have experienced repeated allergic reactions to transfusion should be given pre-treatment with chlorpheniramine. In cases of anaphylaxis, the transfusion should be stopped immediately, and the patient should receive oxygen, adrenaline, corticosteroids, and antihistamines following the ALS protocol.

The table below summarizes the main transfusion reactions and complications, along with their features and management:

Complication | Features | Management
Febrile transfusion reaction | 1 degree rise in temperature, chills, malaise | Supportive care, paracetamol
Acute haemolytic reaction | Fever, chills, pain at transfusion site, nausea, vomiting, dark urine | STOP THE TRANSFUSION, administer IV fluids, diuretics if necessary
Delayed haemolytic reaction | Fever, anaemia, jaundice, haemoglobinuria | Monitor anaemia and renal function, treat as required
Allergic reaction | Urticaria, Pruritus, hives | Symptomatic treatment with ant

To ensure prompt response in case of an adverse reaction, it is important to have adrenaline, antihistamine, and steroid readily available when administering Zagreb antivenom.

Further Reading:

Snake bites in the UK are primarily caused by the adder, which is the only venomous snake species native to the country. While most adder bites result in minor symptoms such as pain, swelling, and inflammation, there have been cases of life-threatening illness and fatalities. Additionally, there are instances where venomous snakes that are kept legally or illegally also cause bites in the UK.

Adder bites typically occur from early spring to late autumn, with the hand being the most common site of the bite. Symptoms can be local or systemic, with local symptoms including sharp pain, tingling or numbness, and swelling that spreads proximally. Systemic symptoms may include spreading pain, tenderness, inflammation, regional lymph node enlargement, and bruising. In severe cases, anaphylaxis can occur, leading to symptoms such as nausea, vomiting, abdominal pain, diarrhea, and shock.

It is important for clinicians to be aware of the potential complications and complications associated with adder bites. These can include acute renal failure, pulmonary and cerebral edema, acute gastric dilatation, paralytic ileus, acute pancreatitis, and coma and seizures. Anaphylaxis symptoms can appear within minutes or be delayed for hours, and hypotension is a critical sign to monitor.

Initial investigations for adder bites include blood tests, ECG, and vital sign monitoring. Further investigations such as chest X-ray may be necessary based on clinical signs. Blood tests may reveal abnormalities such as leukocytosis, raised hematocrit, anemia, thrombocytopenia, and abnormal clotting profile. ECG changes may include tachyarrhythmias, bradyarrhythmias, atrial fibrillation, and ST segment changes.

First aid measures at the scene include immobilizing the patient and the bitten limb, avoiding aspirin and ibuprofen, and cleaning the wound site in the hospital. Tetanus prophylaxis should be considered. In cases of anaphylaxis, prompt administration of IM adrenaline is necessary. In the hospital, rapid assessment and appropriate resuscitation with intravenous fluids are required.

Antivenom may be indicated in cases of hypotension, systemic envenoming, ECG abnormalities, peripheral neutrophil leucocytosis, elevated serum creatine kinase or metabolic acidosis, and extensive or rapidly spreading local swelling. Zagreb antivenom is commonly used in the UK, with an initial dose of 8 mL.