Nitrous oxide should not be used in cases where there is trapped air, such as pneumothorax. This is because nitrous oxide can diffuse into the trapped air and increase the pressure, which can be harmful. This can be particularly dangerous in conditions like pneumothorax, where the trapped air can expand and affect breathing, or in cases of intracranial air after a head injury, trapped air after a recent underwater dive, or recent injection of gas into the eye.

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.

Patients with dental abscess should be evaluated for signs of spread into deep fascial planes. Infection of the sublingual space can lead to serious complications that can be life-threatening. Swelling in this area can cause the tongue to elevate, potentially obstructing the airway. Other complications include infections such as mediastinitis, necrotizing fasciitis, cavernous sinus thrombosis, sepsis, thoracic empyema, Lemierre’s syndrome, cerebral abscess, orbital abscess, and osteomyelitis.

There are certain indications that may require admission to the hospital for dental abscess. These include evidence of significant systemic disturbance, inability to control the infection with antibiotics, rapid spread of infection, stridor or compromised airway, swelling of the sublingual space or pharynx, difficulty swallowing or speaking, immunocompromised patients, abscess requiring drainage under general anesthesia.

Fever and pain are common symptoms of dental abscess but by themselves are not enough to warrant admission. Ideally, dental abscess should be managed through urgent dental review. However, if immediate dental review is not available, the patient may be treated with antibiotics as long as there are no signs of more severe infection.

Further Reading:

Dental abscess is a condition that usually occurs as a result of dental caries or following a dental procedure or trauma. Dental caries refers to the loss of enamel caused by acids produced by bacteria in the mouth. This allows bacteria to enter the pulp, root, and local tissues, leading to infection. The infection can then spread to surrounding tissues, causing conditions such as gingivitis or dental abscess. In severe cases, the infection can spread to deep fascial planes, resulting in conditions like retropharyngeal abscess or Ludwig’s angina.

A dental abscess is typically caused by a combination of gram-positive and gram-negative bacteria, such as Streptococcus, Staphylococcus, and Prevotella. When assessing a patient with a suspected dental abscess, a thorough history and inspection of the mouth, face, and neck are necessary. This helps confirm the diagnosis and assess the risk of serious complications, such as airway compromise or deep/spreading infection.

Some concerning features on history or examination include systemic upset (e.g., fever, vomiting), sublingual or pharyngeal swelling, stridor, dysphagia, dysphonia, dyspnea, and progression of illness despite current antibiotic treatment. It’s important to consider non-dental causes of mouth and jaw pain, such as trauma, referred sinus pain, cardiac pain radiating to the jaw, trigeminal neuralgia, otalgia radiating to the jaw, and parotid gland swelling.

Management of a dental abscess typically involves providing analgesia (NSAIDs and paracetamol) and facilitating early dental review. Antibiotics may be prescribed in certain cases, such as when the patient does not have immediate access to a dentist and is systemically unwell, shows signs of severe infection, or is a high-risk individual (e.g., immunocompromised or diabetic). The choice of antibiotics includes amoxicillin, phenoxymethylpenicillin, or clarithromycin (if penicillin allergic). In severe or spreading infections, metronidazole may be added. The typical course of antibiotics is 5 days.

The term Apparent Life-Threatening Event (ALTE) has traditionally been used to describe a specific type of event. However, in 2016, the American Academy of Paediatrics (AAP) recommended replacing this term with a new one called Brief Resolved Unexplained Event (BRUE).

An ALTE is defined as an episode that is frightening to the observer and is characterized by a combination of symptoms such as apnoea (central or occasionally obstructive), color change (usually cyanotic or pallid but occasionally erythematous or plethoric), significant change in muscle tone (usually marked limpness), choking, or gagging. In some cases, the observer may even fear that the infant has died.

On the other hand, BRUE has stricter criteria and is only applicable to episodes that occur in infants under 12 months old. A BRUE is considered brief, typically lasting 2-30 seconds but no longer than 1 minute. It must also have resolved, meaning the infant has returned to their baseline state. Additionally, it should not be explained by any identifiable medical condition and must be characterized by at least one of the following: cyanosis or pallor, absent, decreased, or irregular breathing, marked change in muscle tone (hyper- or hypotonia), or altered level of responsiveness.

To diagnose a BRUE, a full history and physical examination of the infant must be conducted, and if no explanation for the event is found, it can be classified as a BRUE. Once a BRUE is diagnosed, it can be risk-stratified to guide further management.

A BRUE is considered low risk if the infant has fully recovered, there are no concerning history or physical examination findings, and the following criteria are met: the infant is over 60 days old, born after 32 weeks gestation with a corrected gestational age over 45 weeks, no CPR was performed by a trained healthcare professional, and this was the first event that lasted less than 1 minute.

Low-risk infants can be safely discharged with early outpatient follow-up within 24 hours. However, it is important to involve the parents/caregivers in the decision-making process. They should be informed that a low-risk BRUE is unlikely to indicate a severe underlying disorder and that the event is unlikely to happen again.

Before discharge, it may be advisable to perform an ECG, observe the infant for a brief period, and conduct a pertussis swab

Sialolithiasis is a condition in which a calcified stone (sialolith) forms inside a salivary gland. The submandibular gland (Wharton’s duct) is the most common site, accounting for about 90% of cases, while the parotid gland is the second most affected. In rare instances, sialoliths can also develop in the sublingual gland or minor salivary glands.

The presence of a sialolith obstructs the flow of saliva, leading to pain and swelling in the affected gland during eating. The pain is most intense when salivary flow is high, such as before and during meals, and gradually subsides within an hour after eating. By palpating the floor of the mouth with both hands, a stone may be detected, and sometimes it can even be seen at the opening of the duct. If there is an accompanying infection, pus may be expressed from the gland.

To assess salivary flow, acidic foods like lemon juice can be used as a simple test. X-rays of the mouth’s floor can reveal the presence of a stone. Patients should be referred to an ear, nose, and throat specialist (ENT) for the removal of the stone.

Sialadenitis refers to inflammation of the salivary glands and can be either acute or chronic. Acute sialadenitis is most commonly caused by a bacterial infection, usually ascending from Staphylococcus aureus or Streptococcus viridans. It can occur as a result of sialolithiasis or poor oral hygiene. Clinically, there will be a painful swelling in the affected gland area, with redness of the overlying skin and potential swelling of the cheek and nearby regions. Patients often experience general malaise, with a low-grade fever and elevated inflammatory markers.

Parotitis, on the other hand, refers to inflammation of one or both parotid glands. This inflammation can be caused by bacteria (particularly Staphylococcus aureus), viruses (such as mumps), or tuberculosis.

Sjögren’s syndrome is an autoimmune disorder characterized by dry eyes and dry mouth.

Patients who present with an anticholinergic toxidrome can be difficult to manage due to the agitation and disruptive behavior that is typically present. It is important to provide meticulous supportive care to address the behavioral effects of delirium and prevent complications such as dehydration, injury, and pulmonary aspiration. Often, one-to-one nursing is necessary.

The management approach for these patients is as follows:

1. Resuscitate using a standard ABC approach.
2. Administer sedation for behavioral control. Benzodiazepines, such as IV diazepam in 5 mg-10 mg increments, are the first-line therapy. The goal is to achieve a patient who is sleepy but easily roused. It is important to avoid over-sedating the patient as this can increase the risk of aspiration.
3. Prescribe intravenous fluids as patients are typically unable to eat and drink, and may be dehydrated upon presentation.
4. Insert a urinary catheter as urinary retention is often present and needs to be managed.
5. Consider physostigmine as the specific antidote for anticholinergic delirium in carefully selected cases. Physostigmine acts as a reversible acetylcholinesterase inhibitor, temporarily blocking the breakdown of acetylcholine. This enhances its effects at muscarinic and nicotinic receptors, thereby reversing the effects of the anticholinergic agents.

Physostigmine is indicated in the following situations:

1. Severe anticholinergic delirium that does not respond to benzodiazepine sedation.
2. Poisoning with a pure anticholinergic agent, such as atropine.

The dosage and administration of physostigmine are as follows:

1. Administer in a monitored setting with appropriate staff and resources to manage adverse effects.
2. Perform a 12-lead ECG before administration to rule out bradycardia, AV block, or broadening of the QRS.
3. Administer IV physostigmine 0.5-1 mg as a slow push over 5 minutes. Repeat every 10 minutes up to a maximum of 4 mg.
4. The clinical end-point of therapy is the resolution of delirium.
5. Delirium may reoccur in 1-4 hours as the effects of physostigmine wear off. In such cases, the dose may be cautiously repeated.

The MASCC Risk Index Score, developed by the Multinational Association of Supportive Care in Cancer, is a tool that can be utilized to identify patients who are at low risk for experiencing serious complications of febrile neutropenia. This score takes into account various characteristics of the patient to determine their risk level. For example, patients who have a minimal burden of febrile neutropenia with no or mild symptoms, no hypotension (with a systolic blood pressure above 90 mmHg), and no chronic obstructive pulmonary disease are assigned higher scores. Additionally, patients with a solid tumor or hematological malignancy and no previous fungal infection, as well as those who do not require parental fluids for dehydration, are also given higher scores. On the other hand, patients with a moderate burden of febrile neutropenia symptoms, those in an outpatient setting at the onset of fever, and those under the age of 60 receive lower scores. It is important to note that the qSOFA Score, CURB-65 Score, SCAP Score, and qCSI Score are different tools used for assessing different conditions and are not specifically used in the context of febrile neutropenia.

The process of alcohol oxidation involves two steps. Firstly, alcohol is converted into acetaldehyde, and then acetaldehyde is further converted into acetate. During the oxidation of acetaldehyde, reactive oxygen species are produced along with acetate. This oxidation process is facilitated by three enzyme systems: catalase, CYPE21, and alcohol dehydrogenase. NAD+ acts as a coenzyme for alcohol dehydrogenase during this entire process.

Further Reading:

Alcoholic liver disease (ALD) is a spectrum of disease that ranges from fatty liver at one end to alcoholic cirrhosis at the other. Fatty liver is generally benign and reversible with alcohol abstinence, while alcoholic cirrhosis is a more advanced and irreversible form of the disease. Alcoholic hepatitis, which involves inflammation of the liver, can lead to the development of fibrotic tissue and cirrhosis.

Several factors can increase the risk of progression of ALD, including female sex, genetics, advanced age, induction of liver enzymes by drugs, and co-existent viral hepatitis, especially hepatitis C.

The development of ALD is multifactorial and involves the metabolism of alcohol in the liver. Alcohol is metabolized to acetaldehyde and then acetate, which can result in the production of damaging reactive oxygen species. Genetic polymorphisms and co-existing hepatitis C infection can enhance the pathological effects of alcohol metabolism.

Patients with ALD may be asymptomatic or present with non-specific symptoms such as abdominal discomfort, vomiting, or anxiety. Those with alcoholic hepatitis may have fever, anorexia, and deranged liver function tests. Advanced liver disease can manifest with signs of portal hypertension and cirrhosis, such as ascites, varices, jaundice, and encephalopathy.

Screening tools such as the AUDIT questionnaire can be used to assess alcohol consumption and identify hazardous or harmful drinking patterns. Liver function tests, FBC, and imaging studies such as ultrasound or liver biopsy may be performed to evaluate liver damage.

Management of ALD involves providing advice on reducing alcohol intake, administering thiamine to prevent Wernicke’s encephalopathy, and addressing withdrawal symptoms with benzodiazepines. Complications of ALD, such as intoxication, encephalopathy, variceal bleeding, ascites, hypoglycemia, and coagulopathy, require specialized interventions.

Heavy alcohol use can also lead to thiamine deficiency and the development of Wernicke Korsakoff’s syndrome, characterized by confusion, ataxia, hypothermia, hypotension, nystagmus, and vomiting. Prompt treatment is necessary to prevent progression to Korsakoff’s psychosis.

In summary, alcoholic liver disease is a spectrum of disease that can range from benign fatty liver to irreversible cirrhosis. Risk factors for progression include female sex, genetics, advanced age, drug-induced liver enzyme induction, and co-existing liver conditions.

The diagnosis in this particular case is malignant (accelerated) hypertension. The patient’s blood pressure is greater than 220/110, and they also have retinal haemorrhages and papilloedema. During the examination, it is important to look for other features such as the presence of a 3rd heart sound, ankle oedema, bilateral basal crepitations, and any focal neurological deficit.

Suxamethonium is a medication that can cause an increase in serum potassium levels by causing potassium to leave muscle cells. This can be a problem in patients who already have high levels of potassium, such as those with crush injuries. Therefore, suxamethonium should not be used in these cases.

Further Reading:

Rapid sequence induction (RSI) is a method used to place an endotracheal tube (ETT) in the trachea while minimizing the risk of aspiration. It involves inducing loss of consciousness while applying cricoid pressure, followed by intubation without face mask ventilation. The steps of RSI can be remembered using the 7 P’s: preparation, pre-oxygenation, pre-treatment, paralysis and induction, protection and positioning, placement with proof, and post-intubation management.

Preparation involves preparing the patient, equipment, team, and anticipating any difficulties that may arise during the procedure. Pre-oxygenation is important to ensure the patient has an adequate oxygen reserve and prolongs the time before desaturation. This is typically done by breathing 100% oxygen for 3 minutes. Pre-treatment involves administering drugs to counter expected side effects of the procedure and anesthesia agents used.

Paralysis and induction involve administering a rapid-acting induction agent followed by a neuromuscular blocking agent. Commonly used induction agents include propofol, ketamine, thiopentone, and etomidate. The neuromuscular blocking agents can be depolarizing (such as suxamethonium) or non-depolarizing (such as rocuronium). Depolarizing agents bind to acetylcholine receptors and generate an action potential, while non-depolarizing agents act as competitive antagonists.

Protection and positioning involve applying cricoid pressure to prevent regurgitation of gastric contents and positioning the patient’s neck appropriately. Tube placement is confirmed by visualizing the tube passing between the vocal cords, auscultation of the chest and stomach, end-tidal CO2 measurement, and visualizing misting of the tube. Post-intubation management includes standard care such as monitoring ECG, SpO2, NIBP, capnography, and maintaining sedation and neuromuscular blockade.

Overall, RSI is a technique used to quickly and safely secure the airway in patients who may be at risk of aspiration. It involves a series of steps to ensure proper preparation, oxygenation, drug administration, and tube placement. Monitoring and post-intubation care are also important aspects of RSI.

Shingles is caused by the varicella-zoster virus (VZV), which primarily infects individuals during childhood as chickenpox. However, the initial infection can also be subclinical. After the primary infection, the virus remains dormant in the sensory nervous system, specifically in the geniculate, trigeminal, or dorsal root ganglia.

During the dormant phase, the virus is kept under control by the immune system for many years. However, it can later become active and cause a flare-up in a specific dermatomal segment. This reactivation occurs when the virus travels down the affected nerve over a period of 3 to 5 days, leading to inflammation within and around the nerve. The decline in cell-mediated immunity is believed to trigger the virus’s reactivation.

Several factors can trigger the reactivation of the varicella-zoster virus, including advancing age (with most patients being older than 50), immunosuppressive illnesses, physical trauma, and psychological stress. In immunocompetent patients, the most common site of reactivation is the thoracic nerves, followed by the ophthalmic division of the trigeminal nerve.

Diagnosing shingles can usually be done based on the patient’s history and clinical examination alone, as it has a distinct history and appearance. While various techniques can be used to detect the virus or antibodies, they are often unnecessary. Microscopy and culture tests using scrapings and smears typically yield negative results.

Sheehan’s syndrome is a condition where the pituitary gland becomes damaged due to insufficient blood flow and shock during and after childbirth, leading to hypopituitarism. The risk of developing this syndrome is higher in pregnancies with conditions that increase the chances of bleeding, such as placenta praevia and multiple pregnancies. However, Sheehan’s syndrome is quite rare, affecting only 1 in 10,000 pregnancies.

During pregnancy, the anterior pituitary gland undergoes hypertrophy, making it more vulnerable to ischaemia in the later stages. While the posterior pituitary gland is usually not affected due to its own direct blood supply, there have been rare cases where it is involved. In these instances, central diabetes insipidus, a form of posterior pituitary dysfunction, can occur as a complication of Sheehan’s syndrome.

The clinical features of Sheehan’s syndrome include the absence or infrequency of menstrual periods, the inability to produce milk and breastfeed (galactorrhoea), decreased libido, fatigue and tiredness, loss of pubic and axillary hair, and the potential development of secondary hypothyroidism and adrenal insufficiency. Serum prolactin levels are typically low (less than 5ng/ml). An MRI can be helpful in ruling out other pituitary issues, such as a pituitary tumor.

Treatment for Sheehan’s syndrome involves hormone replacement therapy. With appropriate management, the prognosis for this condition is excellent.

This patient has presented with an Addisonian crisis, which is a rare but potentially catastrophic condition if not diagnosed promptly. The most likely underlying rheumatological diagnosis in this case is polymyalgia rheumatica, and it is likely that the GP started the patient on prednisolone medication.

Addison’s disease occurs when the adrenal glands underproduce steroid hormones, affecting the production of glucocorticoids, mineralocorticoids, and sex steroids. The main causes of Addison’s disease include autoimmune adrenalitis (accounting for 80% of cases), bilateral adrenalectomy, Waterhouse-Friderichsen syndrome (hemorrhage into the adrenal glands), and tuberculosis.

An Addisonian crisis is most commonly triggered by the deliberate or accidental withdrawal of steroid therapy in patients with Addison’s disease. Other factors that can precipitate a crisis include infection, trauma, myocardial infarction, cerebral infarction, asthma, hypothermia, and alcohol abuse.

The clinical features of Addison’s disease include weakness, lethargy, hypotension (especially orthostatic hypotension), nausea, vomiting, weight loss, reduced axillary and pubic hair, depression, and hyperpigmentation (particularly in palmar creases, buccal mucosa, and exposed areas). In an Addisonian crisis, the main features are usually hypoglycemia and shock, characterized by tachycardia, peripheral vasoconstriction, hypotension, altered consciousness, and coma.

Biochemically, Addison’s disease is characterized by increased ACTH levels (as a compensatory response to stimulate the adrenal glands), elevated serum renin levels, hyponatremia, hyperkalemia, hypercalcemia, hypoglycemia, and metabolic acidosis. Diagnostic investigations may include the Synacthen test, plasma ACTH level, plasma renin level, and adrenocortical antibodies.

Management of Addison’s disease should be overseen by an Endocrinologist. Typically, patients require hydrocortisone, fludrocortisone, and dehydroepiandrosterone. Some patients may also need thyroxine if there is hypothalamic-pituitary disease present. Treatment is lifelong, and patients should carry a steroid card and a MedicAlert bracelet, being aware of the possibility of an Addisonian crisis.

Heat stroke is a condition characterized by a core temperature higher than 40.6°C, accompanied by changes in mental state and varying levels of organ dysfunction. There are two forms of heat stroke: classic non-exertional heat stroke, which occurs during high environmental temperatures and typically affects elderly patients during heat waves, and exertional heat stroke, which occurs during strenuous physical exercise in hot conditions, such as endurance athletes competing in hot weather.

The main treatment for heat stroke involves supportive measures. It is important to rapidly reduce the core temperature to around 39.0°C. Patients with severe heat stroke should be managed in a critical care setting. The ABCDE approach should be followed, with a focus on cooling the patient. This includes obtaining a definitive airway if the patient is unresponsive, providing ventilation if necessary, using haemodynamic monitoring to guide fluid therapy, correcting electrolyte imbalances, managing blood glucose levels, removing clothes, eliminating the cause of hyperthermia, and monitoring core and skin temperatures.

There are various cooling techniques that can be used, although there is limited evidence on which approach is the most effective. Some possible methods include simple measures like cold drinks, fanning, ice water packs, and spraying tepid water. Cold water immersion therapy can be beneficial, but it requires the patient to be stable and cooperative, making it impractical for very sick patients. Advanced cooling techniques, such as cold IV fluids, surface cooling devices, intravascular cooling devices, and extracorporeal circuits, may be used for sicker patients.

Benzodiazepines, like diazepam, can be helpful in managing agitation and shivering in heat stroke patients. They not only reduce excessive heat production but also help to calm the patient. In severe cases of agitation, paralysis may be necessary. Dantrolene is commonly used, although there is currently limited high-level evidence to support its use. Neuroleptics, such as chlorpromazine, which were once commonly used, should be avoided due to their potential adverse effects, including lowering the seizure threshold, interfering with thermoregulation, causing anticholinergic side effects, hypotension, and hepatotoxicity.

Patients who have suffered burns should receive high-flow oxygen (15 L) through a reservoir bag while their breathing is being evaluated. If intubation is necessary, it is crucial to use an appropriately sized endotracheal tube (ETT). Using a tube that is too small can make it difficult or even impossible to ventilate the patient, clear secretions, or perform bronchoscopy.

According to the ATLS guidelines, adults should be intubated using an ETT with an internal diameter (ID) of at least 7.5 mm or larger. Children, on the other hand, should have an ETT with an ID of at least 4.5 mm. Once a patient has been intubated, it is important to continue administering 100% oxygen until their carboxyhemoglobin levels drop to less than 5%.

To protect the lungs, it is recommended to use lung protective ventilation techniques. This involves using low tidal volumes (4-8 mL/kg) and ensuring that peak inspiratory pressures do not exceed 30 cmH2O.

All individuals diagnosed with stage 5 chronic kidney disease should be given the option to choose between haemodialysis or peritoneal dialysis. Peritoneal dialysis should be prioritized as the preferred treatment for the following groups of patients: those who still have some remaining kidney function, adult patients without major additional health conditions, and children who are two years old or younger.

During CPR of a hypothermic patient, it is important to follow specific guidelines. If the patient’s core temperature is below 30ºC, resuscitation drugs, such as adrenaline, should be withheld. Once the core temperature rises above 30ºC, cardiac arrest drugs can be administered. However, if the patient’s temperature is between 30-35ºC, the interval for administering cardiac arrest drugs should be doubled. For example, adrenaline should be given every 6-10 minutes instead of the usual 3-5 minutes for a normothermic patient.

Further Reading:

Hypothermic cardiac arrest is a rare situation that requires a tailored approach. Resuscitation is typically prolonged, but the prognosis for young, previously healthy individuals can be good. Hypothermic cardiac arrest may be associated with drowning. Hypothermia is defined as a core temperature below 35ºC and can be graded as mild, moderate, severe, or profound based on the core temperature. When the core temperature drops, basal metabolic rate falls and cell signaling between neurons decreases, leading to reduced tissue perfusion. Signs and symptoms of hypothermia progress as the core temperature drops, initially presenting as compensatory increases in heart rate and shivering, but eventually ceasing as the temperature drops into moderate hypothermia territory.

ECG changes associated with hypothermia include bradyarrhythmias, Osborn waves, prolonged PR, QRS, and QT intervals, shivering artifact, ventricular ectopics, and cardiac arrest. When managing hypothermic cardiac arrest, ALS should be initiated as per the standard ALS algorithm, but with modifications. It is important to check for signs of life, re-warm the patient, consider mechanical ventilation due to chest wall stiffness, adjust dosing or withhold drugs due to slowed drug metabolism, and correct electrolyte disturbances. The resuscitation of hypothermic patients is often prolonged and may continue for a number of hours.

Pulse checks during CPR may be difficult due to low blood pressure, and the pulse check is prolonged to 1 minute for this reason. Drug metabolism is slowed in hypothermic patients, leading to a build-up of potentially toxic plasma concentrations of administered drugs. Current guidance advises withholding drugs if the core temperature is below 30ºC and doubling the drug interval at core temperatures between 30 and 35ºC. Electrolyte disturbances are common in hypothermic patients, and it is important to interpret results keeping the setting in mind. Hypoglycemia should be treated, hypokalemia will often correct as the patient re-warms, ABG analyzers may not reflect the reality of the hypothermic patient, and severe hyperkalemia is a poor prognostic indicator.

Different warming measures can be used to increase the core body temperature, including external passive measures such as removal of wet clothes and insulation with blankets, external active measures such as forced heated air or hot-water immersion, and internal active measures such as inhalation of warm air, warmed intravenous fluids, gastric, bladder, peritoneal and/or pleural lavage and high volume renal haemofilter.

Material risk refers to a significant potential for harm that a reasonable person would consider when deciding whether to undergo a medical or surgical treatment. It is an important factor to consider when obtaining consent for the treatment. Montgomery defines material risk as any risk that a reasonable person in the patient’s position would find significant. Relative risk, on the other hand, compares the risk between two different groups of people. Relative risk reduction measures the decrease in the risk of an adverse event in the treatment group compared to an untreated group. Side effect risk quantifies the likelihood of developing a side effect from a treatment, whether minor or major. Lastly, 1/ARR represents the number needed to treat in order to achieve a desired outcome.

Further Reading:

Patients have the right to determine what happens to their own bodies, and for consent to be valid, certain criteria must be met. These criteria include the person being informed about the intervention, having the capacity to consent, and giving consent voluntarily and freely without any pressure or undue influence.

In order for a person to be deemed to have capacity to make a decision on a medical intervention, they must be able to understand the decision and the information provided, retain that information, weigh up the pros and cons, and communicate their decision.

Valid consent can only be provided by adults, either by the patient themselves, a person authorized under a Lasting Power of Attorney, or someone with the authority to make treatment decisions, such as a court-appointed deputy or a guardian with welfare powers.

In the UK, patients aged 16 and over are assumed to have the capacity to consent. If a patient is under 18 and appears to lack capacity, parental consent may be accepted. However, a young person of any age may consent to treatment if they are considered competent to make the decision, known as Gillick competence. Parental consent may also be given by those with parental responsibility.

The Fraser guidelines apply to the prescription of contraception to under 16’s without parental involvement. These guidelines allow doctors to provide contraceptive advice and treatment without parental consent if certain criteria are met, including the young person understanding the advice, being unable to be persuaded to inform their parents, and their best interests requiring them to receive contraceptive advice or treatment.

Competent adults have the right to refuse consent, even if it is deemed unwise or likely to result in harm. However, there are exceptions to this, such as compulsory treatment authorized by the mental health act or if the patient is under 18 and refusing treatment would put their health at serious risk.

In emergency situations where a patient is unable to give consent, treatment may be provided without consent if it is immediately necessary to save their life or prevent a serious deterioration of their condition. Any treatment decision made without consent must be in the patient’s best interests, and if a decision is time-critical and the patient is unlikely to regain capacity in time, a best interest decision should be made. The treatment provided should be the least restrictive on the patient’s future choices.

Pick’s disease is a rare neurodegenerative disorder that leads to a gradual decline in cognitive function known as frontotemporal dementia. One of the key features of this condition is the accumulation of tau proteins in neurons, forming silver-staining, spherical aggregations called Pick bodies.

Typically, Pick’s disease manifests between the ages of 40 and 60. Initially, individuals may experience changes in their personality, such as disinhibition, tactlessness, and vulgarity. They may also exhibit alterations in their moral values and attempt to distance themselves from their family. Concentration problems, over-activity, pacing, and wandering are also common symptoms during this stage.

What sets Pick’s disease apart from Alzheimer’s disease is that the personality changes occur before memory loss. As the disease progresses, patients will experience deficits in intellect, memory, and language.

On the other hand, Lewy body dementia (LBD) is characterized by the presence of Lewy bodies, which are different from the Pick bodies seen in Pick’s disease.

Excessive intake of lithium is linked to the development of low anion gap acidosis. In cases of lithium overdose, a common outcome is the occurrence of low anion gap acidosis.

Further Reading:

Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.

To reduce the risk of harm to the patient, it is important to test for co-lateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.

Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.

The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.

The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.

The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.

Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.

The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.

The age of the child can help determine the most probable diagnosis. Transient synovitis (irritable hip) is commonly observed in children aged 3 to 10. Septic arthritis is more prevalent in children under 4 years old, while Perthes disease is typically diagnosed between the ages of 4 and 8. SUFE is usually seen in girls around the age of 12 and boys around the age of 13.

Further Reading:

– Transient Synovitis (irritable hip):
– Most common hip problem in children
– Causes transient inflammation of the synovium
– Presents with thigh, groin, and/or hip pain with impaired weight bearing
– Mild to moderate restriction of hip internal rotation is common
– Symptoms usually resolve quickly with rest and anti-inflammatory treatment

– Slipped Upper Femoral Epiphysis (SUFE):
– Displacement of the femoral head epiphysis postero-inferiorly
– Usually affects adolescents
– Can present acutely following trauma or with chronic, persistent symptoms
– Associated with loss of internal rotation of the leg in flexion
– Treatment involves surgical fixation by pinning

– Perthes disease:
– Degenerative condition affecting the hip joints of children
– Avascular necrosis of the femoral head is the cause
– Presents with hip pain, limp, stiffness, and reduced range of hip movements
– X-ray changes include widening of joint space and decreased femoral head size/flattening
– Treatment can be conservative or operative, depending on the severity

– Important differentials:
– Septic arthritis: Acute hip pain associated with systemic upset and severe limitation of affected joint
– Non-accidental injury (NAI): Should be considered in younger children and toddlers presenting with a limp, even without a trauma history
– Malignancy: Rare, but osteosarcoma may present with hip pain or limp, especially in tall teenage boys
– Developmental dysplasia of the hip: Often picked up on newborn examination with positive Barlow and Ortolani tests
– Juvenile idiopathic arthritis (JIA): Joint pain and swelling, limp, positive ANA in some cases
– Coagulopathy: Haemophilia, HSP, and sickle cell disease can cause hip pain through different mechanisms

People with chronic mitral regurgitation often experience atrial fibrillation.

Mitral Stenosis:
– Causes: Rheumatic fever, Mucopolysaccharidoses, Carcinoid, Endocardial fibroelastosis
– Features: Mid-late diastolic murmur, loud S1, opening snap, low volume pulse, malar flush, atrial fibrillation, signs of pulmonary edema, tapping apex beat
– Features of severe mitral stenosis: Length of murmur increases, opening snap becomes closer to S2
– Investigation findings: CXR may show left atrial enlargement, echocardiography may show reduced cross-sectional area of the mitral valve

Mitral Regurgitation:
– Causes: Mitral valve prolapse, Myxomatous degeneration, Ischemic heart disease, Rheumatic fever, Connective tissue disorders, Endocarditis, Dilated cardiomyopathy
– Features: pansystolic murmur radiating to left axilla, soft S1, S3, laterally displaced apex beat with heave
– Signs of acute MR: Decompensated congestive heart failure symptoms
– Signs of chronic MR: Leg edema, fatigue, arrhythmia (atrial fibrillation)
– Investigation findings: Doppler echocardiography to detect regurgitant flow and pulmonary hypertension, ECG may show signs of LA enlargement and LV hypertrophy, CXR may show LA and LV enlargement in chronic MR and pulmonary edema in acute MR.

The traffic light system is a useful tool for evaluating the potential risk of serious illness in children. This system categorizes clinical features into three groups based on severity: red (high-risk), amber (intermediate-risk), and green (low-risk).

Children displaying any of the following symptoms or signs fall into the high-risk group for serious illness: pale/mottled/ashen/blue skin, lips or tongue; lack of response to social cues; appearing unwell to a healthcare professional; inability to wake or stay awake when roused; weak, high-pitched, or continuous cry; grunting; respiratory rate exceeding 60 breaths per minute; moderate or severe chest indrawing; reduced skin turgor; and bulging fontanelle.

Children exhibiting any of the following symptoms or signs are considered at least intermediate-risk for serious illness: pallor of skin, lips or tongue reported by parent or caregiver; abnormal response to social cues; absence of a smile; waking only with prolonged stimulation; decreased activity; nasal flaring; dry mucous membranes; poor feeding in infants; reduced urine output; and rigors.

Children displaying any of the following symptoms or signs are classified as low-risk for serious illness: normal color of skin, lips, and tongue; normal response to social cues; contentment and smiles; staying awake or quickly awakening; strong normal cry or absence of crying; normal skin and eyes; and moist mucous membranes.

To summarize, children with fever and any symptoms or signs in the red column are considered high-risk, while those with fever and any symptoms or signs in the amber column (but none in the red column) are considered intermediate-risk. Children with symptoms and signs in the green column (and none in the amber or red columns) are classified as low-risk.

For more information, you can refer to the NICE guidelines on the assessment and initial management of fever in children under 5, as well as the NICE Clinical Knowledge Summary on the management of feverish children.

According to the latest guidelines from NICE and the BNF, the recommended initial treatment for typhoid fever is cefotaxime. It is important to note that infections originating from the Middle-East, South Asia, and South-East Asia may have multiple antibiotic resistance, so it is advisable to test for sensitivity. In cases where the microorganism is found to be sensitive, ciprofloxacin can be considered as a suitable alternative.

For patients with croup, the usual dose of oral dexamethasone is 0.15mg/kg. However, if the patient cannot take it orally, an alternative option is to administer intramuscular dexamethasone at a dose of 0.6 mg/kg as a single dose.

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

Ketamine induces a distinct type of sedation known as dissociative sedation. This sedation state is unlike any other and is characterized by a trance-like, cataleptic condition. It provides deep pain relief and memory loss while still maintaining important protective reflexes for the airway, spontaneous breathing, and overall stability of the heart and lungs. Dissociative sedation with ketamine does not fit into the conventional categories of sedation.

Further Reading:

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

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

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

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

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

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

Public Health England (PHE) has the primary goal of promptly identifying potential disease outbreaks and epidemics. While accuracy of diagnosis is not the main focus, clinical suspicion of a notifiable infection has been sufficient since 1968.

Registered medical practitioners (RMPs) are legally obligated to inform the designated proper officer at their local council or local health protection team (HPT) about suspected cases of specific infectious diseases.

The Health Protection (Notification) Regulations 2010 outline the diseases that RMPs must report to the proper officers at local authorities. These diseases include acute encephalitis, acute infectious hepatitis, acute meningitis, acute poliomyelitis, anthrax, botulism, brucellosis, cholera, COVID-19, diphtheria, enteric fever (typhoid or paratyphoid fever), food poisoning, haemolytic uraemic syndrome (HUS), infectious bloody diarrhoea, invasive group A streptococcal disease, Legionnaires’ disease, leprosy, malaria, measles, meningococcal septicaemia, mumps, plague, rabies, rubella, severe acute respiratory syndrome (SARS), scarlet fever, smallpox, tetanus, tuberculosis, typhus, viral haemorrhagic fever (VHF), whooping cough, and yellow fever.

Septic arthritis occurs when an infectious agent invades a joint, causing it to become purulent. The main symptoms of septic arthritis include pain in the affected joint, redness, warmth, and swelling of the joint, and difficulty moving the joint. Patients may also experience fever and systemic upset. The most common cause of septic arthritis is Staphylococcus aureus, but other bacteria such as Streptococcus spp., Haemophilus influenzae, Neisseria gonorrhoea, and Escherichia coli can also be responsible.

According to the current recommendations by NICE and the BNF, the initial treatment for septic arthritis is flucloxacillin. However, if a patient is allergic to penicillin, clindamycin can be used instead. If there is a suspicion of MRSA infection, vancomycin is the recommended choice. In cases where gonococcal arthritis or a Gram-negative infection is suspected, cefotaxime is the preferred treatment. The suggested duration of treatment is typically 4-6 weeks, although it may be longer if the infection is complicated.

Respiratory alkalosis can be caused by hyperventilation, such as during periods of anxiety. It can also be a result of conditions like pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, or the early stages of aspirin overdose.

Respiratory acidosis is often associated with chronic obstructive pulmonary disease (COPD) or life-threatening asthma. Other causes include pulmonary edema, sedative drug overdose (such as opiates or benzodiazepines), neuromuscular disease, obesity, or certain medications.

Metabolic alkalosis can occur due to vomiting, potassium depletion (often caused by diuretic usage), Cushing’s syndrome, or Conn’s syndrome.

Metabolic acidosis with a raised anion gap can be caused by conditions like lactic acidosis (which can result from hypoxemia, shock, sepsis, or infarction) or ketoacidosis (commonly seen in diabetes, starvation, or alcohol excess). Other causes include renal failure or poisoning (such as late stages of aspirin overdose, methanol, or ethylene glycol).

Metabolic acidosis with a normal anion gap can be attributed to conditions like renal tubular acidosis, diarrhea, ammonium chloride ingestion, or adrenal insufficiency.

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

The causes of Le Fort fractures vary depending on the type of fracture. Common mechanisms include motor vehicle accidents, sports injuries, assaults, and falls from significant heights. Patients with Le Fort fractures often have concurrent head and cervical spine injuries. Additionally, they frequently experience other facial fractures, as well as neuromuscular injuries and dental avulsions.

The specific type of fracture sustained is determined by the direction of the force applied to the face. Le Fort type I fractures typically occur when a force is directed downward against the upper teeth. Le Fort type II fractures are usually the result of a force applied to the lower or mid maxilla. Lastly, Le Fort type III fractures are typically caused by a force applied to the nasal bridge and upper part of the maxilla.

Activated charcoal is a commonly used substance for decontamination in cases of poisoning. Its main function is to adsorb the molecules of the ingested toxin onto its surface.

Activated charcoal is a chemically inert form of carbon. It is a fine black powder that has no odor or taste. It is produced by subjecting carbonaceous matter to high temperatures, a process known as pyrolysis, and then concentrating it with a zinc chloride solution. This creates a network of pores within the charcoal, giving it a large absorptive area of approximately 3,000 m2/g. This porous structure helps prevent the absorption of the harmful toxin by up to 50%.

The usual dosage of activated charcoal is 50 grams for adults and 1 gram per kilogram of body weight for children. It can be administered orally or through a nasogastric tube. It is important to give the charcoal within one hour of ingestion, and it may be repeated after one hour if necessary.

However, there are certain situations where activated charcoal should not be used. If the patient is unconscious or in a coma, there is a risk of aspiration, so the charcoal should not be given. Similarly, if seizures are likely to occur, there is a risk of aspiration and the charcoal should be avoided. Additionally, if there is reduced gastrointestinal motility, there is a risk of obstruction, so activated charcoal should not be used in such cases.

Activated charcoal is effective in treating overdose with various drugs and toxins, including aspirin, paracetamol, barbiturates, tricyclic antidepressants, digoxin, amphetamines, morphine, cocaine, and phenothiazines. However, it is ineffective in treating overdose with substances such as iron, lithium, boric acid, cyanide, ethanol, ethylene glycol, methanol, malathion, DDT, carbamate, hydrocarbon, strong acids, or alkalis.

There are some potential adverse effects associated with activated charcoal. These include nausea and vomiting, diarrhea, constipation, bezoar formation (a mass of undigested material that can cause blockages), bowel obstruction, pulmonary aspiration (inhaling the charcoal into the lungs), and impaired absorption of oral medications or antidotes.