Sodium bicarbonate is used to treat severe TCA toxicity by reducing the risk of seizures and arrhythmia. The goal is to increase the serum pH to a range of 7.45 to 7.55 through alkalinisation.

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.

An abnormal QTc, which is the measurement of the time it takes for the heart to recharge between beats, is generally considered to be greater than 450 ms in males. However, some sources may use a cutoff of greater than 440 ms as abnormal in males. To further categorize the QTc, a measurement of 430ms or less is considered normal, 431-450 ms is borderline, and 450 ms or more is considered abnormal in males. Females typically have a longer QTc, so the categories for them are often quoted as less than 450 ms being normal, 451-470 ms being borderline, and greater than 470ms being abnormal.

Further Reading:

Long QT syndrome (LQTS) is a condition characterized by a prolonged QT interval on an electrocardiogram (ECG), which represents abnormal repolarization of the heart. LQTS can be either acquired or congenital. Congenital LQTS is typically caused by gene abnormalities that affect ion channels responsible for potassium or sodium flow in the heart. There are 15 identified genes associated with congenital LQTS, with three genes accounting for the majority of cases. Acquired LQTS can be caused by various factors such as certain medications, electrolyte imbalances, hypothermia, hypothyroidism, and bradycardia from other causes.

The normal QTc values, which represent the corrected QT interval for heart rate, are typically less than 450 ms for men and less than 460ms for women. Prolonged QTc intervals are considered to be greater than these values. It is important to be aware of drugs that can cause QT prolongation, as this can lead to potentially fatal arrhythmias. Some commonly used drugs that can cause QT prolongation include antimicrobials, antiarrhythmics, antipsychotics, antidepressants, antiemetics, and others.

Management of long QT syndrome involves addressing any underlying causes and using beta blockers. In some cases, an implantable cardiac defibrillator (ICD) may be recommended for patients who have experienced recurrent arrhythmic syncope, documented torsades de pointes, previous ventricular tachyarrhythmias or torsades de pointes, previous cardiac arrest, or persistent syncope. Permanent pacing may be used in patients with bradycardia or atrioventricular nodal block and prolonged QT. Mexiletine is a treatment option for those with LQT3. Cervicothoracic sympathetic denervation may be considered in patients with recurrent syncope despite beta-blockade or in those who are not ideal candidates for an ICD. The specific treatment options for LQTS depend on the type and severity of the condition.

When patients with diabetic ketoacidosis (DKA) are treated with insulin infusion, it is expected that their plasma bicarbonate levels will increase by at least 3 mmol/L per hour. Insulin therapy is aimed at correcting both hyperglycemia and ketoacidosis. However, if capillary ketones are not decreasing by at least 0.5 mmol/L per hour, venous bicarbonate is not rising by at least 3 mmol/L per hour, or plasma glucose is not decreasing by at least 3 mmol/L per hour, the insulin infusion rate should be reevaluated.

Further Reading:

Diabetic ketoacidosis (DKA) is a serious complication of diabetes that occurs due to a lack of insulin in the body. It is most commonly seen in individuals with type 1 diabetes but can also occur in type 2 diabetes. DKA is characterized by hyperglycemia, acidosis, and ketonaemia.

The pathophysiology of DKA involves insulin deficiency, which leads to increased glucose production and decreased glucose uptake by cells. This results in hyperglycemia and osmotic diuresis, leading to dehydration. Insulin deficiency also leads to increased lipolysis and the production of ketone bodies, which are acidic. The body attempts to buffer the pH change through metabolic and respiratory compensation, resulting in metabolic acidosis.

DKA can be precipitated by factors such as infection, physiological stress, non-compliance with insulin therapy, acute medical conditions, and certain medications. The clinical features of DKA include polydipsia, polyuria, signs of dehydration, ketotic breath smell, tachypnea, confusion, headache, nausea, vomiting, lethargy, and abdominal pain.

The diagnosis of DKA is based on the presence of ketonaemia or ketonuria, blood glucose levels above 11 mmol/L or known diabetes mellitus, and a blood pH below 7.3 or bicarbonate levels below 15 mmol/L. Initial investigations include blood gas analysis, urine dipstick for glucose and ketones, blood glucose measurement, and electrolyte levels.

Management of DKA involves fluid replacement, electrolyte correction, insulin therapy, and treatment of any underlying cause. Fluid replacement is typically done with isotonic saline, and potassium may need to be added depending on the patient’s levels. Insulin therapy is initiated with an intravenous infusion, and the rate is adjusted based on blood glucose levels. Monitoring of blood glucose, ketones, bicarbonate, and electrolytes is essential, and the insulin infusion is discontinued once ketones are below 0.3 mmol/L, pH is above 7.3, and bicarbonate is above 18 mmol/L.

Complications of DKA and its treatment include gastric stasis, thromboembolism, electrolyte disturbances, cerebral edema, hypoglycemia, acute respiratory distress syndrome, and acute kidney injury. Prompt medical intervention is crucial in managing DKA to prevent potentially fatal outcomes.

One way to assess for digoxin toxicity is by examining the patient’s electrocardiogram (ECG) for specific characteristics. In the case of digoxin toxicity, ECG findings may include downsloping ST depression, prolonged QT interval, tall tented T-waves, and possibly delta waves. However, a short PR interval (< 120ms) is not typically associated with digoxin toxicity. Further Reading: Digoxin is a medication used for rate control in atrial fibrillation and for improving symptoms in heart failure. It works by decreasing conduction through the atrioventricular node and increasing the force of cardiac muscle contraction. However, digoxin toxicity can occur, and plasma concentration alone does not determine if a patient has developed toxicity. Symptoms of digoxin toxicity include feeling generally unwell, lethargy, nausea and vomiting, anorexia, confusion, yellow-green vision, arrhythmias, and gynaecomastia. ECG changes seen in digoxin toxicity include downsloping ST depression with a characteristic Salvador Dali sagging appearance, flattened, inverted, or biphasic T waves, shortened QT interval, mild PR interval prolongation, and prominent U waves. There are several precipitating factors for digoxin toxicity, including hypokalaemia, increasing age, renal failure, myocardial ischaemia, electrolyte imbalances, hypoalbuminaemia, hypothermia, hypothyroidism, and certain medications such as amiodarone, quinidine, verapamil, and diltiazem. Management of digoxin toxicity involves the use of digoxin specific antibody fragments, also known as Digibind or digifab. Arrhythmias should be treated, and electrolyte disturbances should be corrected with close monitoring of potassium levels. It is important to note that digoxin toxicity can be precipitated by hypokalaemia, and toxicity can then lead to hyperkalaemia.

The mortality rate linked to sepsis can vary depending on various factors such as the patient’s age, overall health, and the severity of the infection. However, on average, the mortality rate for sepsis is estimated to be around 30%.

Further Reading:

There are multiple definitions of sepsis, leading to confusion among healthcare professionals. The Sepsis 3 definition describes sepsis as life-threatening organ dysfunction caused by a dysregulated host response to infection. The Sepsis 2 definition includes infection plus two or more SIRS criteria. The NICE definition states that sepsis is a clinical syndrome triggered by the presence of infection in the blood, activating the body’s immune and coagulation systems. The Sepsis Trust defines sepsis as a dysregulated host response to infection mediated by the immune system, resulting in organ dysfunction, shock, and potentially death.

The confusion surrounding sepsis terminology is further compounded by the different versions of sepsis definitions, known as Sepsis 1, Sepsis 2, and Sepsis 3. The UK organizations RCEM and NICE have not fully adopted the changes introduced in Sepsis 3, causing additional confusion. While Sepsis 3 introduces the use of SOFA scores and abandons SIRS criteria, NICE and the Sepsis Trust have rejected the use of SOFA scores and continue to rely on SIRS criteria. This discrepancy creates challenges for emergency department doctors in both exams and daily clinical practice.

To provide some clarity, RCEM now recommends referring to national standards organizations such as NICE, SIGN, BTS, or others relevant to the area. The Sepsis Trust, in collaboration with RCEM and NICE, has published a toolkit that serves as a definitive reference point for sepsis management based on the sepsis 3 update.

There is a consensus internationally that the terms SIRS and severe sepsis are outdated and should be abandoned. Instead, the terms sepsis and septic shock should be used. NICE defines septic shock as a life-threatening condition characterized by low blood pressure despite adequate fluid replacement and organ dysfunction or failure. Sepsis 3 defines septic shock as persisting hypotension requiring vasopressors to maintain a mean arterial pressure of 65 mmHg or more, along with a serum lactate level greater than 2 mmol/l despite adequate volume resuscitation.

NICE encourages clinicians to adopt an approach of considering sepsis in all patients, rather than relying solely on strict definitions. Early warning or flag systems can help identify patients with possible sepsis.

Von Willebrand disease (vWD) is a common hereditary coagulation disorder that affects approximately 1 in 100 individuals. It occurs due to a deficiency in Von Willebrand factor (vWF), which plays a crucial role in blood clotting. vWF not only binds to factor VIII to protect it from rapid breakdown, but it is also necessary for proper platelet adhesion. When vWF is lacking, both factor VIII levels and platelet function are affected, leading to prolonged APTT and bleeding time. However, the platelet count and thrombin time remain unaffected.

While some individuals with vWD may not experience any symptoms and are diagnosed incidentally during a clotting profile check, others may present with easy bruising, nosebleeds (epistaxis), and heavy menstrual bleeding (menorrhagia). In severe cases, more significant bleeding and joint bleeding (haemarthrosis) can occur.

For mild cases of von Willebrand disease, bleeding can be managed with desmopressin. This medication works by stimulating the release of vWF stored in the Weibel-Palade bodies, which are storage granules found in the endothelial cells lining the blood vessels and heart. By increasing the patient’s own levels of vWF, desmopressin helps improve clotting. In more severe cases, replacement therapy is necessary. This involves infusing cryoprecipitate or Factor VIII concentrate to provide the missing vWF. Replacement therapy is particularly recommended for patients with severe von Willebrand’s disease who are undergoing moderate or major surgical procedures.

The current algorithm for the treatment of a convulsing child, known as APLS, is as follows:

Step 1 (5 minutes after the start of convulsion):
If a child has been convulsing for 5 minutes or more, the initial dose of benzodiazepine should be administered. This can be done by giving Lorazepam at a dose of 0.1 mg/kg intravenously (IV) or intraosseously (IO) if vascular access is available. Alternatively, buccal midazolam at a dose of 0.5 mg/kg or rectal diazepam at a dose of 0.5 mg/kg can be given if vascular access is not available.

Step 2 (10 minutes after the start of Step 1):
If the convulsion continues for a further 10 minutes, a second dose of benzodiazepine should be given. It is also important to summon senior help at this point.

Step 3 (10 minutes after the start of Step 2):
At this stage, it is necessary to involve senior help to reassess the child and provide guidance on further management. The recommended approach is as follows:
– If the child is not already on phenytoin, a phenytoin infusion should be initiated. This involves administering 20 mg/kg of phenytoin intravenously over a period of 20 minutes.
– If the child is already taking phenytoin, phenobarbitone can be used as an alternative. The recommended dose is 20 mg/kg administered intravenously over 20 minutes.
– In the meantime, rectal paraldehyde can be considered at a dose of 0.8 ml/kg of the 50:50 mixture while preparing the infusion.

Step 4 (20 minutes after the start of Step 3):
If the child is still experiencing convulsions at this stage, it is crucial to have an anaesthetist present. A rapid sequence induction with thiopental is recommended for further management.

Please note that this algorithm is subject to change based on individual patient circumstances and the guidance of medical professionals.

Rapid tranquillisation involves the administration of medication through injection when oral medication is not feasible or appropriate and immediate sedation is necessary. The current guidelines from NICE recommend two options for rapid tranquillisation in adults: intramuscular lorazepam alone or a combination of intramuscular haloperidol and intramuscular promethazine. The choice of medication depends on various factors such as advanced statements, potential intoxication, previous responses to these medications, interactions with other drugs, and existing physical health conditions or pregnancy.

If there is insufficient information to determine the appropriate medication or if the individual has not taken antipsychotic medication before, intramuscular lorazepam is recommended. However, if there is evidence of cardiovascular disease or a prolonged QT interval, or if an electrocardiogram has not been conducted, the combination of intramuscular haloperidol and intramuscular promethazine should be avoided, and intramuscular lorazepam should be used instead.

If there is a partial response to intramuscular lorazepam, a second dose should be considered. If there is no response to intramuscular lorazepam, then intramuscular haloperidol combined with intramuscular promethazine should be considered. If there is a partial response to this combination, a further dose should be considered.

If there is no response to intramuscular haloperidol combined with intramuscular promethazine and intramuscular lorazepam has not been used yet, it should be considered. However, if intramuscular lorazepam has already been administered, it is recommended to arrange an urgent team meeting to review the situation and seek a second opinion if necessary.

After rapid tranquillisation, the patient should be closely monitored for any side effects, and their vital signs should be regularly checked, including heart rate, blood pressure, respiratory rate, temperature, hydration level, and level of consciousness. These observations should be conducted at least hourly until there are no further concerns about the patient’s physical health.

For more information, refer to the NICE guidance on violence and aggression: short-term management in mental health, health, and community settings.

Fractures that extend into the calcaneocuboid joint are commonly intra-articular. It is recommended to refer patients to orthopaedics for further evaluation and treatment. Conservative management usually involves keeping the patient non-weight bearing for a period of 6-12 weeks.

Further Reading:

Calcaneus fractures are a common type of lower limb and joint injury. The calcaneus, or heel bone, is the most frequently fractured tarsal bone. These fractures are often intra-articular, meaning they involve the joint. The most common cause of calcaneus fractures is a fall or jump from a height.

When assessing calcaneus fractures, X-rays are used to visualize the fracture lines. Two angles are commonly assessed to determine the severity of the fracture. Böhler’s angle, which measures the angle between two tangent lines drawn across the anterior and posterior borders of the calcaneus, should be between 20-40 degrees. If it is less than 20 degrees, it indicates a calcaneal fracture with flattening. The angle of Gissane, which measures the depression of the posterior facet of the subtalar joint, should be between 120-145 degrees. An increased angle of Gissane suggests a calcaneal fracture.

In the emergency department, the management of a fractured calcaneus involves identifying the injury and any associated injuries, providing pain relief, elevating the affected limb(s), and referring the patient to an orthopedic specialist. It is important to be aware that calcaneus fractures are often accompanied by other injuries, such as bilateral fractures of vertebral fractures.

The definitive management of a fractured calcaneus can be done conservatively or through surgery, specifically open reduction internal fixation (ORIF). The orthopedic team will typically order a CT or MRI scan to classify the fracture and determine the most appropriate treatment. However, a recent UK heel fracture trial suggests that in most cases, ORIF does not improve fracture outcomes.

Le Fort fractures are complex fractures of the midface that involve the maxillary bone and surrounding structures. These fractures can occur in a horizontal, pyramidal, or transverse direction. The distinguishing feature of Le Fort fractures is the traumatic separation of the pterygomaxillary region. They make up approximately 10% to 20% of all facial fractures and can have severe consequences, both in terms of potential life-threatening injuries and disfigurement.

The Le Fort classification system categorizes midface fractures into three groups based on the plane of injury. As the classification level increases, the location of the maxillary fracture moves from inferior to superior within the maxilla.

Le Fort I fractures are horizontal fractures that occur across the lower aspect of the maxilla. These fractures cause the teeth to separate from the upper face and extend through the lower nasal septum, the lateral wall of the maxillary sinus, and into the palatine bones and pterygoid plates. They are sometimes referred to as a floating palate because they often result in the mobility of the hard palate from the midface. Common accompanying symptoms include facial swelling, loose teeth, dental fractures, and misalignment of the teeth.

Le Fort II fractures are pyramidal-shaped fractures, with the base of the pyramid located at the level of the teeth and the apex at the nasofrontal suture. The fracture line extends from the nasal bridge and passes through the superior wall of the maxilla, the lacrimal bones, the inferior orbital floor and rim, and the anterior wall of the maxillary sinus. These fractures are sometimes called a floating maxilla because they typically result in the mobility of the maxilla from the midface. Common symptoms include facial swelling, nosebleeds, subconjunctival hemorrhage, cerebrospinal fluid leakage from the nose, and widening and flattening of the nasal bridge.

Le Fort III fractures are transverse fractures of the midface. The fracture line passes through the nasofrontal suture, the maxillo frontal suture, the orbital wall, and the zygomatic arch and zygomaticofrontal suture. These fractures cause separation of all facial bones from the cranial base, earning them the nickname craniofacial disjunction or floating face fractures. They are the rarest and most severe type of Le Fort fracture. Common symptoms include significant facial swelling, bruising around the eyes, facial flattening, and the entire face can be shifted.

In order to achieve satisfactory bronchodilation, most individuals require a plasma theophylline concentration of 10-20 mg/litre (55-110 micromol/litre). However, it is possible for a lower concentration to still be effective. Adverse effects can occur within the range of 10-20 mg/litre, and their frequency and severity increase when concentrations exceed 20 mg/litre.

To measure plasma theophylline concentration, a blood sample should be taken five days after starting oral treatment and at least three days after any dose adjustment. For modified-release preparations, the blood sample should typically be taken 4-6 hours after an oral dose (specific sampling times may vary, so it is advisable to consult local guidelines). If aminophylline is administered intravenously, a blood sample should be taken 4-6 hours after initiating treatment.

Etomidate is not recommended for use in septic patients because it can suppress adrenal cortisol production, leading to increased morbidity and mortality in sepsis cases. However, it is a suitable choice for haemodynamically unstable patients who are not experiencing sepsis, as it does not cause significant hypotension like other induction agents. Additionally, etomidate can be beneficial for patients with head injuries and elevated intracranial pressure, as it reduces cerebral blood flow and intracranial pressure.

Further Reading:

There are four commonly used induction agents in the UK: propofol, ketamine, thiopentone, and etomidate.

Propofol is a 1% solution that produces significant venodilation and myocardial depression. It can also reduce cerebral perfusion pressure. The typical dose for propofol is 1.5-2.5 mg/kg. However, it can cause side effects such as hypotension, respiratory depression, and pain at the site of injection.

Ketamine is another induction agent that produces a dissociative state. It does not display a dose-response continuum, meaning that the effects do not necessarily increase with higher doses. Ketamine can cause bronchodilation, which is useful in patients with asthma. The initial dose for ketamine is 0.5-2 mg/kg, with a typical IV dose of 1.5 mg/kg. Side effects of ketamine include tachycardia, hypertension, laryngospasm, unpleasant hallucinations, nausea and vomiting, hypersalivation, increased intracranial and intraocular pressure, nystagmus and diplopia, abnormal movements, and skin reactions.

Thiopentone is an ultra-short acting barbiturate that acts on the GABA receptor complex. It decreases cerebral metabolic oxygen and reduces cerebral blood flow and intracranial pressure. The adult dose for thiopentone is 3-5 mg/kg, while the child dose is 5-8 mg/kg. However, these doses should be halved in patients with hypovolemia. Side effects of thiopentone include venodilation, myocardial depression, and hypotension. It is contraindicated in patients with acute porphyrias and myotonic dystrophy.

Etomidate is the most haemodynamically stable induction agent and is useful in patients with hypovolemia, anaphylaxis, and asthma. It has similar cerebral effects to thiopentone. The dose for etomidate is 0.15-0.3 mg/kg. Side effects of etomidate include injection site pain, movement disorders, adrenal insufficiency, and apnoea. It is contraindicated in patients with sepsis due to adrenal suppression.

The most suitable approach for investigation in this case would be to send a blood test for Epstein-Barr virus (EBV) viral serology. Glandular fever, also known as infectious mononucleosis, is commonly caused by the Epstein-Barr virus. The symptoms described by the patient, including a sore throat, fever, and feeling unwell, are consistent with this condition. To confirm the diagnosis, a blood test for EBV viral serology can be performed. This test detects antibodies produced by the body in response to the virus. It is important to note that the Monospot test, which is another blood test for infectious mononucleosis, may not be as accurate in younger children. Therefore, the most appropriate option would be to send a blood test for EBV viral serology in 2-3 days time. This will allow for the detection of specific antibodies and provide a more accurate diagnosis.

Further Reading:

Glandular fever, also known as infectious mononucleosis or mono, is a clinical syndrome characterized by symptoms such as sore throat, fever, and swollen lymph nodes. It is primarily caused by the Epstein-Barr virus (EBV), with other viruses and infections accounting for the remaining cases. Glandular fever is transmitted through infected saliva and primarily affects adolescents and young adults. The incubation period is 4-8 weeks.

The majority of EBV infections are asymptomatic, with over 95% of adults worldwide having evidence of prior infection. Clinical features of glandular fever include fever, sore throat, exudative tonsillitis, lymphadenopathy, and prodromal symptoms such as fatigue and headache. Splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver) may also be present, and a non-pruritic macular rash can sometimes occur.

Glandular fever can lead to complications such as splenic rupture, which increases the risk of rupture in the spleen. Approximately 50% of splenic ruptures associated with glandular fever are spontaneous, while the other 50% follow trauma. Diagnosis of glandular fever involves various investigations, including viral serology for EBV, monospot test, and liver function tests. Additional serology tests may be conducted if EBV testing is negative.

Management of glandular fever involves supportive care and symptomatic relief with simple analgesia. Antiviral medication has not been shown to be beneficial. It is important to identify patients at risk of serious complications, such as airway obstruction, splenic rupture, and dehydration, and provide appropriate management. Patients can be advised to return to normal activities as soon as possible, avoiding heavy lifting and contact sports for the first month to reduce the risk of splenic rupture.

Rare but serious complications associated with glandular fever include hepatitis, upper airway obstruction, cardiac complications, renal complications, neurological complications, haematological complications, chronic fatigue, and an increased risk of lymphoproliferative cancers and multiple sclerosis.

Intubation is rarely necessary for asthmatic patients, with only about 2% of asthma attacks requiring it. Most severe cases can be managed using non-invasive ventilation techniques. However, intubation can be a life-saving measure for asthmatic patients in critical condition. The indications for intubation include severe hypoxia, altered mental state, failure to respond to medications or non-invasive ventilation, and respiratory or cardiac arrest.

Before intubation, it is important to preoxygenate the patient and administer intravenous fluids. Nasal oxygen during intubation can provide additional time. Intravenous fluids are crucial because patients with acute asthma exacerbations can experience significant fluid loss, which can lead to severe hypotension during intubation and positive pressure ventilation.

There is no perfect combination of drugs for rapid sequence induction (RSI), but ketamine is often the preferred choice. Ketamine has bronchodilatory properties and does not cause hypotension as a side effect. Propofol can also be used, but it carries a risk of hypotension. In some cases, a subdissociative dose of ketamine can be helpful to facilitate the use of non-invasive ventilation in a hypoxic or combative patient.

Rocuronium and suxamethonium are commonly used as paralytic agents. Rocuronium has the advantage of providing a longer period of paralysis, which helps avoid ventilator asynchrony in the early stages of management.

Proper mechanical ventilation is essential, and it involves allowing the patient enough time to fully exhale the delivered breath and prevent hyperinflation. Therefore, permissive hypercapnia is typically used, and the ventilator settings should be adjusted accordingly. The recommended settings are a respiratory rate of 6-8 breaths per minute and a tidal volume of 6 ml per kilogram of body weight.

Whooping cough is a respiratory infection caused by the bacteria Bordetella pertussis. It is highly contagious and can be transmitted to about 90% of close household contacts. The Health Protection Agency has identified two priority groups for public health action in managing whooping cough contacts.

Group 1 consists of individuals who are at a higher risk of severe or complicated infection. This includes infants under one year old who have received less than three doses of the pertussis vaccine.

Group 2 consists of individuals who are at a higher risk of transmitting the infection to those in Group 1. This includes pregnant women who are at or beyond 32 weeks of gestation, healthcare workers who work with infants and pregnant women, individuals who work with infants too young to be vaccinated (under 4 months old), and individuals who share a household with infants too young to be vaccinated.

According to current guidance, antibiotic prophylaxis with a macrolide antibiotic, like erythromycin, should only be offered to close contacts if two criteria are met. First, the index case (the person with whooping cough) must have developed symptoms within the past 21 days. Second, there must be a close contact in one of the two priority groups.

If both criteria are met, all contacts, regardless of their vaccination status and age, should be offered chemoprophylaxis. In this case, the mother is in Group 2, so the current recommendation is that all household contacts, including the mother, father, and brother, should receive chemoprophylaxis.

Additionally, immunization or a booster dose should be considered for those who have been offered chemoprophylaxis, depending on their current vaccination status.

Phyllocontin Continus contains aminophylline, which is a combination of theophylline and ethylenediamine. It is a bronchodilator that is commonly used to manage COPD and asthma.

In this case, the woman is showing symptoms of theophylline toxicity, which may have been triggered by the antibiotic prescribed for her urinary tract infection. Quinolone antibiotics, like ciprofloxacin, can increase the concentration of theophyllines in the blood, leading to toxicity.

There are other medications that can also interact with theophyllines. These include macrolide antibiotics such as clarithromycin, allopurinol, antifungals like ketoconazole, and calcium-channel blockers such as amlodipine. It is important to be aware of these interactions to prevent any potential complications.

Etomidate is a derivative of imidazole that is commonly used to induce anesthesia due to its short-acting nature. Its main mechanism of action is believed to involve the modulation of fast inhibitory synaptic transmission within the central nervous system by acting on GABA type A receptors.

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.

During the first trimester of pregnancy, the use of warfarin can lead to a condition known as fetal warfarin syndrome. This condition is characterized by nasal hypoplasia, bone stippling, bilateral optic atrophy, and intellectual disability in the baby. However, if warfarin is taken during the second or third trimester, it can cause optic atrophy, cataracts, microcephaly, microphthalmia, intellectual disability, and both fetal and maternal hemorrhage.

There are several other drugs that can have adverse effects during pregnancy. For example, ACE inhibitors like ramipril can cause hypoperfusion, renal failure, and the oligohydramnios sequence if taken during the second and third trimesters. Aminoglycosides such as gentamicin can lead to ototoxicity and deafness in the baby. High doses of aspirin can result in first trimester abortions, delayed onset labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. However, low doses of aspirin (e.g. 75 mg) do not pose significant risks.

Benzodiazepines like diazepam, when taken late in pregnancy, can cause respiratory depression and a neonatal withdrawal syndrome. Calcium-channel blockers, if taken during the first trimester, can cause phalangeal abnormalities, while their use in the second and third trimesters can lead to fetal growth retardation. Carbamazepine can result in hemorrhagic disease of the newborn and neural tube defects. Chloramphenicol can cause gray baby syndrome. Corticosteroids, if taken during the first trimester, may cause orofacial clefts.

Danazol, if taken during the first trimester, can cause masculinization of the female fetuses genitals. Finasteride should not be handled by pregnant women as crushed or broken tablets can be absorbed through the skin and affect male sex organ development. Haloperidol, if taken during the first trimester, may cause limb malformations, while its use in the third trimester increases the risk of extrapyramidal symptoms in the newborn.

Heparin can lead to maternal bleeding and thrombocytopenia. Isoniazid can cause maternal liver damage and neuropathy and seizures in the baby. Isotretinoin carries a high risk of teratogenicity, including multiple congenital malformations and spontaneous abortion.

Urinary retention can be caused by various drug classes. One such class is 5α-reductase inhibitors like finasteride, which are prescribed to alleviate obstructive symptoms caused by an enlarged prostate. Some commonly known drugs that can lead to urinary retention include alcohol, anticholinergics, decongestants (such as phenylephrine and pseudoephedrine), disopyramide, antihistamines (like diphenhydramine and phenergan), and amphetamines.

Further Reading:

Urinary retention is the inability to completely or partially empty the bladder. It is commonly seen in elderly males with prostate enlargement and acute retention. Symptoms of acute urinary retention include the inability to void, inability to empty the bladder, overflow incontinence, and suprapubic discomfort. Chronic urinary retention, on the other hand, is typically painless but can lead to complications such as hydronephrosis and renal impairment.

There are various causes of urinary retention, including anatomical factors such as urethral stricture, bladder neck contracture, and prostate enlargement. Functional causes can include neurogenic bladder, neurological diseases like multiple sclerosis and Parkinson’s, and spinal cord injury. Certain drugs can also contribute to urinary retention, such as anticholinergics, opioids, and tricyclic antidepressants. In female patients, specific causes like organ prolapse, pelvic mass, and gravid uterus should be considered.

The pathophysiology of acute urinary retention can involve factors like increased resistance to flow, detrusor muscle dysfunction, bladder overdistension, and drugs that affect bladder tone. The primary management intervention for acute urinary retention is the insertion of a urinary catheter. If a catheter cannot be passed through the urethra, a suprapubic catheter can be inserted. Post-catheterization residual volume should be measured, and renal function should be assessed through U&Es and urine culture. Further evaluation and follow-up with a urologist are typically arranged, and additional tests like ultrasound may be performed if necessary. It is important to note that PSA testing is often deferred for at least two weeks after catheter insertion and female patients with retention should also be referred to urology for investigation.

The guidelines from the British Thoracic Society (BTS) recommend conducting investigations for Legionella infection in the following cases: severe community-acquired pneumonia, patients with specific risk factors, and during outbreaks of community-acquired pneumonia. To confirm a case, the Public Health England (PHE) requires one of the following: isolation and culture of Legionella species from clinical specimens (typically sputum), seroconversion with a four-fold increase in titre of indirect immunofluorescent antibody test (IFAT) using a validated technique, or confirmation of Legionella pneumophila urinary antigen using validated reagents or kits. The gold standard for confirmation is the isolation and culture of Legionella species, while cases of Pontiac fever are usually culture-negative. The HPA considers a case presumptive if there is a clinical diagnosis of pneumonia with a single high titre of 128 using IFAT, or a single titre of 64 in an outbreak. A positive result by direct immunofluorescence on a clinical specimen using validated monoclonal antibodies is also considered a presumptive case.

One of the signs of digoxin toxicity is yellow-green vision. Other clinical features include feeling generally unwell, lethargy, nausea and vomiting, loss of appetite, confusion, and the development of arrhythmias such as AV block and bradycardia.

Further Reading:

Digoxin is a medication used for rate control in atrial fibrillation and for improving symptoms in heart failure. It works by decreasing conduction through the atrioventricular node and increasing the force of cardiac muscle contraction. However, digoxin toxicity can occur, and plasma concentration alone does not determine if a patient has developed toxicity. Symptoms of digoxin toxicity include feeling generally unwell, lethargy, nausea and vomiting, anorexia, confusion, yellow-green vision, arrhythmias, and gynaecomastia.

ECG changes seen in digoxin toxicity include downsloping ST depression with a characteristic Salvador Dali sagging appearance, flattened, inverted, or biphasic T waves, shortened QT interval, mild PR interval prolongation, and prominent U waves. There are several precipitating factors for digoxin toxicity, including hypokalaemia, increasing age, renal failure, myocardial ischaemia, electrolyte imbalances, hypoalbuminaemia, hypothermia, hypothyroidism, and certain medications such as amiodarone, quinidine, verapamil, and diltiazem.

Management of digoxin toxicity involves the use of digoxin specific antibody fragments, also known as Digibind or digifab. Arrhythmias should be treated, and electrolyte disturbances should be corrected with close monitoring of potassium levels. It is important to note that digoxin toxicity can be precipitated by hypokalaemia, and toxicity can then lead to hyperkalaemia.

Chlamydia trachomatis is a type of Gram-negative bacteria that is responsible for causing the sexually transmitted infection known as chlamydia. This bacterium is typically either coccoid or rod-shaped in its appearance.

There are various serological variants of C. trachomatis, and each variant is associated with different patterns of disease. Specifically, types D-K are responsible for causing genitourinary infections.

In the United Kingdom, chlamydia is the most commonly diagnosed sexually transmitted infection (STI). It is also the leading preventable cause of infertility worldwide. Interestingly, around 50% of men infected with chlamydia do not experience any symptoms, while at least 70% of infected women are asymptomatic.

If left untreated, chlamydia can lead to various complications. In women, these complications may include pelvic inflammatory disease (PID), ectopic pregnancy, and tubal infertility. Men, on the other hand, may experience complications such as proctitis, epididymitis, and epididymo-orchitis.

Diabetes insipidus (DI) is characterized by specific biochemical markers. One of these markers is a low urine osmolality, meaning that the concentration of solutes in the urine is lower than normal. In contrast, the serum osmolality, which measures the concentration of solutes in the blood, is high in individuals with DI. This combination of low urine osmolality and high serum osmolality is indicative of DI. Other common biochemical disturbances associated with DI include elevated plasma osmolality, polyuria (excessive urine production), and hypernatremia (high sodium levels in the blood). However, it is important to note that sodium levels can sometimes be within the normal range in individuals with DI. It is worth mentioning that conditions such as Addison’s disease, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and primary polydipsia are associated with low serum osmolality and hyponatremia. Additionally, the use of selective serotonin reuptake inhibitors (SSRIs) can also lead to hyponatremia as a side effect.

Further Reading:

Diabetes insipidus (DI) is a condition characterized by either a decrease in the secretion of antidiuretic hormone (cranial DI) or insensitivity to antidiuretic hormone (nephrogenic DI). Antidiuretic hormone, also known as arginine vasopressin, is produced in the hypothalamus and released from the posterior pituitary. The typical biochemical disturbances seen in DI include elevated plasma osmolality, low urine osmolality, polyuria, and hypernatraemia.

Cranial DI can be caused by various factors such as head injury, CNS infections, pituitary tumors, and pituitary surgery. Nephrogenic DI, on the other hand, can be genetic or result from electrolyte disturbances or the use of certain drugs. Symptoms of DI include polyuria, polydipsia, nocturia, signs of dehydration, and in children, irritability, failure to thrive, and fatigue.

To diagnose DI, a 24-hour urine collection is done to confirm polyuria, and U&Es will typically show hypernatraemia. High plasma osmolality with low urine osmolality is also observed. Imaging studies such as MRI of the pituitary, hypothalamus, and surrounding tissues may be done, as well as a fluid deprivation test to evaluate the response to desmopressin.

Management of cranial DI involves supplementation with desmopressin, a synthetic form of arginine vasopressin. However, hyponatraemia is a common side effect that needs to be monitored. In nephrogenic DI, desmopressin supplementation is usually not effective, and management focuses on ensuring adequate fluid intake to offset water loss and monitoring electrolyte levels. Causative drugs need to be stopped, and there is a risk of developing complications such as hydroureteronephrosis and an overdistended bladder.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by the excessive and uncontrollable release of antidiuretic hormone (ADH). This can occur either from the posterior pituitary gland or from an abnormal non-pituitary source. There are various conditions that can disrupt the regulation of ADH secretion in the central nervous system and lead to SIADH. These include CNS damage such as meningitis or subarachnoid hemorrhage, paraneoplastic syndromes like small cell carcinoma of the lung, infections such as atypical pneumonia or cerebral abscess, and certain drugs like carbamazepine, TCAs, and SSRIs.

The typical biochemical profile observed in SIADH is characterized by low levels of serum sodium (usually less than 135 mmol/l), low serum osmolality, and high urine osmolality.

The earliest ECG change typically observed in hyperkalemia is the presence of tall tented T-waves.

Further Reading:

Vasoactive drugs can be classified into three categories: inotropes, vasopressors, and unclassified. Inotropes are drugs that alter the force of muscular contraction, particularly in the heart. They primarily stimulate adrenergic receptors and increase myocardial contractility. Commonly used inotropes include adrenaline, dobutamine, dopamine, isoprenaline, and ephedrine.

Vasopressors, on the other hand, increase systemic vascular resistance (SVR) by stimulating alpha-1 receptors, causing vasoconstriction. This leads to an increase in blood pressure. Commonly used vasopressors include norepinephrine, metaraminol, phenylephrine, and vasopressin.

Electrolytes, such as potassium, are essential for proper bodily function. Solutions containing potassium are often given to patients to prevent or treat hypokalemia (low potassium levels). However, administering too much potassium can lead to hyperkalemia (high potassium levels), which can cause dangerous arrhythmias. It is important to monitor potassium levels and administer it at a controlled rate to avoid complications.

Hyperkalemia can be caused by various factors, including excessive potassium intake, decreased renal excretion, endocrine disorders, certain medications, metabolic acidosis, tissue destruction, and massive blood transfusion. It can present with cardiovascular, respiratory, gastrointestinal, and neuromuscular symptoms. ECG changes, such as tall tented T-waves, prolonged PR interval, flat P-waves, widened QRS complex, and sine wave, are also characteristic of hyperkalemia.

In summary, vasoactive drugs can be categorized as inotropes, vasopressors, or unclassified. Inotropes increase myocardial contractility, while vasopressors increase systemic vascular resistance. Electrolytes, particularly potassium, are important for bodily function, but administering too much can lead to hyperkalemia. Monitoring potassium levels and ECG changes is crucial in managing hyperkalemia.

During cardiac arrest, Lidocaine is administered through a slow IV injection at an initial dose of 1 mg/kg when deemed suitable.

Further Reading:

In the management of respiratory and cardiac arrest, several drugs are commonly used to help restore normal function and improve outcomes. Adrenaline is a non-selective agonist of adrenergic receptors and is administered intravenously at a dose of 1 mg every 3-5 minutes. It works by causing vasoconstriction, increasing systemic vascular resistance (SVR), and improving cardiac output by increasing the force of heart contraction. Adrenaline also has bronchodilatory effects.

Amiodarone is another drug used in cardiac arrest situations. It blocks voltage-gated potassium channels, which prolongs repolarization and reduces myocardial excitability. The initial dose of amiodarone is 300 mg intravenously after 3 shocks, followed by a dose of 150 mg after 5 shocks.

Lidocaine is an alternative to amiodarone in cardiac arrest situations. It works by blocking sodium channels and decreasing heart rate. The recommended dose is 1 mg/kg by slow intravenous injection, with a repeat half of the initial dose after 5 minutes. The maximum total dose of lidocaine is 3 mg/kg.

Magnesium sulfate is used to reverse myocardial hyperexcitability associated with hypomagnesemia. It is administered intravenously at a dose of 2 g over 10-15 minutes. An additional dose may be given if necessary, but the maximum total dose should not exceed 3 g.

Atropine is an antagonist of muscarinic acetylcholine receptors and is used to counteract the slowing of heart rate caused by the parasympathetic nervous system. It is administered intravenously at a dose of 500 mcg every 3-5 minutes, with a maximum dose of 3 mg.

Naloxone is a competitive antagonist for opioid receptors and is used in cases of respiratory arrest caused by opioid overdose. It has a short duration of action, so careful monitoring is necessary. The initial dose of naloxone is 400 micrograms, followed by 800 mcg after 1 minute. The dose can be gradually escalated up to 2 mg per dose if there is no response to the preceding dose.

It is important for healthcare professionals to have knowledge of the pharmacology and dosing schedules of these drugs in order to effectively manage respiratory and cardiac arrest situations.

The recommended maximum infusion rate for IV fluids containing potassium is 10 mmol/hr in normal circumstances outside of the HDU/ICU setting, according to NHS SPS. However, in certain situations, higher infusion rates may be used. The BNF advises a maximum infusion rate of 20 mmol/hr for saline containing KCl, which is commonly administered to patients with DKA. If infusion rates exceed 10 mmol/hr, it is recommended to administer the fluids ideally in a HDU/level 2/ICU setting, through a central line, using an infusion pump, and with cardiac monitoring in place.

Further Reading:

Vasoactive drugs can be classified into three categories: inotropes, vasopressors, and unclassified. Inotropes are drugs that alter the force of muscular contraction, particularly in the heart. They primarily stimulate adrenergic receptors and increase myocardial contractility. Commonly used inotropes include adrenaline, dobutamine, dopamine, isoprenaline, and ephedrine.

Vasopressors, on the other hand, increase systemic vascular resistance (SVR) by stimulating alpha-1 receptors, causing vasoconstriction. This leads to an increase in blood pressure. Commonly used vasopressors include norepinephrine, metaraminol, phenylephrine, and vasopressin.

Electrolytes, such as potassium, are essential for proper bodily function. Solutions containing potassium are often given to patients to prevent or treat hypokalemia (low potassium levels). However, administering too much potassium can lead to hyperkalemia (high potassium levels), which can cause dangerous arrhythmias. It is important to monitor potassium levels and administer it at a controlled rate to avoid complications.

Hyperkalemia can be caused by various factors, including excessive potassium intake, decreased renal excretion, endocrine disorders, certain medications, metabolic acidosis, tissue destruction, and massive blood transfusion. It can present with cardiovascular, respiratory, gastrointestinal, and neuromuscular symptoms. ECG changes, such as tall tented T-waves, prolonged PR interval, flat P-waves, widened QRS complex, and sine wave, are also characteristic of hyperkalemia.

In summary, vasoactive drugs can be categorized as inotropes, vasopressors, or unclassified. Inotropes increase myocardial contractility, while vasopressors increase systemic vascular resistance. Electrolytes, particularly potassium, are important for bodily function, but administering too much can lead to hyperkalemia. Monitoring potassium levels and ECG changes is crucial in managing hyperkalemia.

The tricuspid valve is the most commonly affected valve in cases of infective endocarditis among intravenous drug users. This means that when IV drug users develop infective endocarditis, it is most likely to affect the tricuspid valve. On the other hand, in cases of native valve endocarditis and prosthetic valve endocarditis, the mitral valve is the valve that is most commonly affected.

Further Reading:

Infective endocarditis (IE) is an infection that affects the innermost layer of the heart, known as the endocardium. It is most commonly caused by bacteria, although it can also be caused by fungi or viruses. IE can be classified as acute, subacute, or chronic depending on the duration of illness. Risk factors for IE include IV drug use, valvular heart disease, prosthetic valves, structural congenital heart disease, previous episodes of IE, hypertrophic cardiomyopathy, immune suppression, chronic inflammatory conditions, and poor dental hygiene.

The epidemiology of IE has changed in recent years, with Staphylococcus aureus now being the most common causative organism in most industrialized countries. Other common organisms include coagulase-negative staphylococci, streptococci, and enterococci. The distribution of causative organisms varies depending on whether the patient has a native valve, prosthetic valve, or is an IV drug user.

Clinical features of IE include fever, heart murmurs (most commonly aortic regurgitation), non-specific constitutional symptoms, petechiae, splinter hemorrhages, Osler’s nodes, Janeway’s lesions, Roth’s spots, arthritis, splenomegaly, meningism/meningitis, stroke symptoms, and pleuritic pain.

The diagnosis of IE is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Major criteria include positive blood cultures with typical microorganisms and positive echocardiogram findings. Minor criteria include fever, vascular phenomena, immunological phenomena, and microbiological phenomena. Blood culture and echocardiography are key tests for diagnosing IE.

In summary, infective endocarditis is an infection of the innermost layer of the heart that is most commonly caused by bacteria. It can be classified as acute, subacute, or chronic and can be caused by a variety of risk factors. Staphylococcus aureus is now the most common causative organism in most industrialized countries. Clinical features include fever, heart murmurs, and various other symptoms. The diagnosis is based on the modified Duke criteria, which require the presence of certain major and minor criteria. Blood culture and echocardiography are important tests for diagnosing IE.

Acne conglobata is an extremely severe form of acne where acne nodules come together and create sinuses. Acne fulminans, on the other hand, is a rare and severe complication of acne conglobata that is accompanied by systemic symptoms. It is linked to elevated levels of androgenic hormones, specific autoimmune conditions, and a genetic predisposition.

The typical clinical characteristics of acne fulminans are as follows:

– Sudden and abrupt onset
– Inflammatory and ulcerated nodular acne primarily found on the chest and back
– Often painful lesions
– Ulcers on the upper trunk covered with bleeding crusts
– Severe acne scarring
– Fluctuating fever
– Painful joints and arthropathy
– General feeling of illness (malaise)
– Loss of appetite and weight loss
– Enlarged liver and spleen (hepatosplenomegaly)

It is crucial to refer patients immediately for a specialist evaluation and hospital admission. Treatment options for acne fulminans include systemic corticosteroids, dapsone, ciclosporin, and high-dose intravenous antibiotics.