Prolonged QRS duration is associated with an increased risk of seizures and arrhythmia. Therefore, when QRS prolongation is observed, it is recommended to consider initiating treatment with sodium bicarbonate.

Further Reading:

Tricyclic antidepressant (TCA) overdose is a common occurrence in emergency departments, with drugs like amitriptyline and dosulepin being particularly dangerous. TCAs work by inhibiting the reuptake of norepinephrine and serotonin in the central nervous system. In cases of toxicity, TCAs block various receptors, including alpha-adrenergic, histaminic, muscarinic, and serotonin receptors. This can lead to symptoms such as hypotension, altered mental state, signs of anticholinergic toxicity, and serotonin receptor effects.

TCAs primarily cause cardiac toxicity by blocking sodium and potassium channels. This can result in a slowing of the action potential, prolongation of the QRS complex, and bradycardia. However, the blockade of muscarinic receptors also leads to tachycardia in TCA overdose. QT prolongation and Torsades de Pointes can occur due to potassium channel blockade. TCAs can also have a toxic effect on the myocardium, causing decreased cardiac contractility and hypotension.

Early symptoms of TCA overdose are related to their anticholinergic properties and may include dry mouth, pyrexia, dilated pupils, agitation, sinus tachycardia, blurred vision, flushed skin, tremor, and confusion. Severe poisoning can lead to arrhythmias, seizures, metabolic acidosis, and coma. ECG changes commonly seen in TCA overdose include sinus tachycardia, widening of the QRS complex, prolongation of the QT interval, and an R/S ratio >0.7 in lead aVR.

Management of TCA overdose involves ensuring a patent airway, administering activated charcoal if ingestion occurred within 1 hour and the airway is intact, and considering gastric lavage for life-threatening cases within 1 hour of ingestion. Serial ECGs and blood gas analysis are important for monitoring. Intravenous fluids and correction of hypoxia are the first-line therapies. IV sodium bicarbonate is used to treat haemodynamic instability caused by TCA overdose, and benzodiazepines are the treatment of choice for seizure control. Other treatments that may be considered include glucagon, magnesium sulfate, and intravenous lipid emulsion.

There are certain things to avoid in TCA overdose, such as anti-arrhythmics like quinidine and flecainide, as they can prolonged depolarization.

Alteplase (rt-pA) is a recommended treatment for acute ischaemic stroke in adults if it is initiated within 4.5 hours of the onset of stroke symptoms. It is crucial to exclude intracranial haemorrhage through appropriate imaging techniques before starting the treatment. The initial dose of alteplase is 0.9 mg/kg, with a maximum of 90 mg. This dose is administered intravenously over a period of 60 minutes. The first 10% of the dose is given through intravenous injection, while the remaining amount is administered through intravenous infusion. For more information, please refer to the NICE guidelines on stroke and transient ischaemic attack in individuals aged 16 and above.

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.

The most appropriate next step in managing this patient is to rapidly infuse 10 ml/kg of 0.9% sodium chloride solution intravenously. This is because the girl is showing signs of severe dehydration, such as lethargy, decreased urine output, mottled skin, and prolonged capillary refill time. Rapid intravenous fluid administration is necessary to quickly restore her fluid volume and prevent further complications.

Further Reading:

Gastroenteritis is a common condition in children, particularly those under the age of 5. It is characterized by the sudden onset of diarrhea, with or without vomiting. The most common cause of gastroenteritis in infants and young children is rotavirus, although other viruses, bacteria, and parasites can also be responsible. Prior to the introduction of the rotavirus vaccine in 2013, rotavirus was the leading cause of gastroenteritis in children under 5 in the UK. However, the vaccine has led to a significant decrease in cases, with a drop of over 70% in subsequent years.

Norovirus is the most common cause of gastroenteritis in adults, but it also accounts for a significant number of cases in children. In England & Wales, there are approximately 8,000 cases of norovirus each year, with 15-20% of these cases occurring in children under 9.

When assessing a child with gastroenteritis, it is important to consider whether there may be another more serious underlying cause for their symptoms. Dehydration assessment is also crucial, as some children may require intravenous fluids. The NICE traffic light system can be used to identify the risk of serious illness in children under 5.

In terms of investigations, stool microbiological testing may be indicated in certain cases, such as when the patient has been abroad, if diarrhea lasts for more than 7 days, or if there is uncertainty over the diagnosis. U&Es may be necessary if intravenous fluid therapy is required or if there are symptoms and/or signs suggestive of hypernatremia. Blood cultures may be indicated if sepsis is suspected or if antibiotic therapy is planned.

Fluid management is a key aspect of treating children with gastroenteritis. In children without clinical dehydration, normal oral fluid intake should be encouraged, and oral rehydration solution (ORS) supplements may be considered. For children with dehydration, ORS solution is the preferred method of rehydration, unless intravenous fluid therapy is necessary. Intravenous fluids may be required for children with shock or those who are unable to tolerate ORS solution.

Antibiotics are generally not required for gastroenteritis in children, as most cases are viral or self-limiting. However, there are some exceptions, such as suspected or confirmed sepsis, Extraintestinal spread of bacterial infection, or specific infections like Clostridium difficile-associated pseudomembranous enterocolitis or giardiasis.

The first heart sound (S1) is created by vibrations produced when the mitral and tricuspid valves close. It occurs at the end of diastole and the start of ventricular systole, coming before the upstroke of the carotid pulsation.

A sample of the normal heart sounds can be listened to here (courtesy of Littman stethoscopes).

A loud S1 can be associated with the following conditions:
– Increased transvalvular gradient (e.g. mitral stenosis, tricuspid stenosis)
– Increased force of ventricular contraction (e.g. tachycardia, hyperdynamic states like fever and thyrotoxicosis)
– Shortened PR interval (e.g. Wolff-Parkinson-White syndrome)
– Mitral valve prolapse
– Thin individuals

A soft S1 can be associated with the following conditions:
– Inappropriate apposition of the AV valves (e.g. mitral regurgitation, tricuspid regurgitation)
– Prolonged PR interval (e.g. heart block, digoxin toxicity)
– Decreased force of ventricular contraction (e.g. myocarditis, myocardial infarction)
– Increased distance from the heart (e.g. obesity, emphysema, pericardial effusion)

A split S1 can be associated with the following conditions:
– Right bundle branch block
– LV pacing
– Ebstein anomaly

Shenton’s line is a useful tool for identifying hip fractures on radiographs. It is a curved line that is drawn along the bottom edge of the upper pubic bone and the inner lower edge of the femur neck. This line should be smooth and uninterrupted. If there are any breaks or irregularities in the line, it could indicate a fracture, dysplasia, or dislocation.

Further Reading:

Fractured neck of femur is a common injury, especially in elderly patients who have experienced a low impact fall. Risk factors for this type of fracture include falls, osteoporosis, and other bone disorders such as metastatic cancers, hyperparathyroidism, and osteomalacia.

There are different classification systems for hip fractures, but the most important differentiation is between intracapsular and extracapsular fractures. The blood supply to the femoral neck and head is primarily from ascending cervical branches that arise from an arterial anastomosis between the medial and lateral circumflex branches of the femoral arteries. Fractures in the intracapsular region can damage the blood supply and lead to avascular necrosis (AVN), with the risk increasing with displacement. The Garden classification can be used to classify intracapsular neck of femur fractures and determine the risk of AVN. Those at highest risk will typically require hip replacement or arthroplasty.

Fractures below or distal to the capsule are termed extracapsular and can be further described as intertrochanteric or subtrochanteric depending on their location. The blood supply to the femoral neck and head is usually maintained with these fractures, making them amenable to surgery that preserves the femoral head and neck, such as dynamic hip screw fixation.

Diagnosing hip fractures can be done through radiographs, with Shenton’s line and assessing the trabecular pattern of the proximal femur being helpful techniques. X-rays should be obtained in both the AP and lateral views, and if an occult fracture is suspected, an MRI or CT scan may be necessary.

In terms of standards of care, it is important to assess the patient’s pain score within 15 minutes of arrival in the emergency department and provide appropriate analgesia within the recommended timeframes. Patients with moderate or severe pain should have their pain reassessed within 30 minutes of receiving analgesia. X-rays should be obtained within 120 minutes of arrival, and patients should be admitted within 4 hours of arrival.

Sodium bicarbonate is recommended as a treatment for TCA overdose according to the latest guidelines from RCEM and NPIS in 2021. Previous editions also suggested using glucagon if IV fluids and sodium bicarbonate were ineffective in treating the overdose.

Further Reading:

Tricyclic antidepressant (TCA) overdose is a common occurrence in emergency departments, with drugs like amitriptyline and dosulepin being particularly dangerous. TCAs work by inhibiting the reuptake of norepinephrine and serotonin in the central nervous system. In cases of toxicity, TCAs block various receptors, including alpha-adrenergic, histaminic, muscarinic, and serotonin receptors. This can lead to symptoms such as hypotension, altered mental state, signs of anticholinergic toxicity, and serotonin receptor effects.

TCAs primarily cause cardiac toxicity by blocking sodium and potassium channels. This can result in a slowing of the action potential, prolongation of the QRS complex, and bradycardia. However, the blockade of muscarinic receptors also leads to tachycardia in TCA overdose. QT prolongation and Torsades de Pointes can occur due to potassium channel blockade. TCAs can also have a toxic effect on the myocardium, causing decreased cardiac contractility and hypotension.

Early symptoms of TCA overdose are related to their anticholinergic properties and may include dry mouth, pyrexia, dilated pupils, agitation, sinus tachycardia, blurred vision, flushed skin, tremor, and confusion. Severe poisoning can lead to arrhythmias, seizures, metabolic acidosis, and coma. ECG changes commonly seen in TCA overdose include sinus tachycardia, widening of the QRS complex, prolongation of the QT interval, and an R/S ratio >0.7 in lead aVR.

Management of TCA overdose involves ensuring a patent airway, administering activated charcoal if ingestion occurred within 1 hour and the airway is intact, and considering gastric lavage for life-threatening cases within 1 hour of ingestion. Serial ECGs and blood gas analysis are important for monitoring. Intravenous fluids and correction of hypoxia are the first-line therapies. IV sodium bicarbonate is used to treat haemodynamic instability caused by TCA overdose, and benzodiazepines are the treatment of choice for seizure control. Other treatments that may be considered include glucagon, magnesium sulfate, and intravenous lipid emulsion.

There are certain things to avoid in TCA overdose, such as anti-arrhythmics like quinidine and flecainide, as they can prolonged depolarization.

The differences in anti-inflammatory activity among NSAIDs are minimal, but there is significant variation in how individuals respond to and tolerate these drugs. Approximately 60% of patients will experience a positive response to any NSAID, and those who do not respond to one may find relief with another. Pain relief typically begins shortly after taking the first dose, and a full analgesic effect is usually achieved within a week. However, it may take up to 3 weeks to see an anti-inflammatory effect, which may not be easily assessed. If desired results are not achieved within these timeframes, it is recommended to try a different NSAID.

NSAIDs work by reducing the production of prostaglandins through the inhibition of the enzyme cyclo-oxygenase. Different NSAIDs vary in their selectivity for inhibiting different types of cyclo-oxygenase. Selective inhibition of cyclo-oxygenase-2 is associated with a lower risk of gastrointestinal intolerance. Other factors also play a role in susceptibility to gastrointestinal effects, so the choice of NSAID should consider the incidence of gastrointestinal and other side effects.

Ibuprofen, a propionic acid derivative, possesses anti-inflammatory, analgesic, and antipyretic properties. It generally has fewer side effects compared to other non-selective NSAIDs, but its anti-inflammatory properties are weaker. For rheumatoid arthritis, doses of 1.6 to 2.4 g daily are required, and it may not be suitable for conditions where inflammation is prominent, such as acute gout.

Naproxen is often a preferred choice due to its combination of good efficacy and low incidence of side effects. However, it does have a higher occurrence of side effects compared to ibuprofen.

Ketoprofen and diclofenac have similar anti-inflammatory properties to ibuprofen but are associated with more side effects.

Indometacin has an action that is equal to or superior to naproxen, but it also has a high incidence of side effects, including headache, dizziness, and gastrointestinal disturbances.

Biliary colic occurs when a gallstone temporarily blocks either the cystic duct or Hartmann’s pouch, causing the gallbladder to contract. The blockage is relieved when the stone either falls back into the gallbladder or passes through the duct.

Located at the junction of the gallbladder’s neck and the cystic duct, there is a protrusion in the gallbladder wall known as Hartmann’s pouch. This is the most common site for gallstones to become stuck and cause cholestasis.

Patients experiencing biliary colic typically present with intermittent, cramp-like pain in the upper right quadrant of the abdomen. The pain can last anywhere from 15 minutes to 24 hours and is often accompanied by feelings of nausea and vomiting. It is not uncommon for the pain to radiate to the right scapula area.

The superior orbital fissure is a gap in the back wall of the orbit, created by the space between the greater and lesser wings of the sphenoid bone. Several structures pass through it to enter the orbit, starting from the top and going downwards. These include the lacrimal nerve (a branch of CN V1), the frontal nerve (another branch of CN V1), the superior ophthalmic vein, the trochlear nerve (CN IV), the superior division of the oculomotor nerve (CN III), the nasociliary nerve (a branch of CN V1), the inferior division of the oculomotor nerve (CN III), the abducens nerve (CN VI), and the inferior ophthalmic vein.

Adjacent to the superior orbital fissure, on the back wall of the orbit and towards the middle, is the optic canal. The optic nerve (CN II) exits the orbit through this canal, along with the ophthalmic artery.

Superior orbital fissure syndrome (SOFS) is a condition characterized by a combination of symptoms and signs that occur when cranial nerves III, IV, V1, and VI are compressed or injured as they pass through the superior orbital fissure. This condition also leads to swelling and protrusion of the eye due to impaired drainage and congestion. The main causes of SOFS are trauma, tumors, and inflammation. It is important to note that CN II is not affected by this syndrome, as it follows a separate path through the optic canal.