If you have missed one pill, which means it has been 48-72 hours since you took the last pill in your current packet or you started the first pill in a new packet 24-48 hours late, you need to take the missed pill as soon as you remember. Make sure to continue taking the remaining pills at your usual time. Emergency contraception is generally not necessary in this situation, but it may be worth considering if you have missed pills earlier in the packet or during the last week of the previous packet.

The effects of adrenaline on alpha-adrenergic receptors result in the narrowing of blood vessels throughout the body, leading to increased pressure in the coronary and cerebral arteries. On the other hand, the effects of adrenaline on beta-adrenergic receptors enhance the strength of the heart’s contractions and increase the heart rate, which can potentially improve blood flow to the coronary and cerebral arteries. However, it is important to note that these positive effects may be counteracted by the simultaneous increase in oxygen consumption by the heart, the occurrence of abnormal heart rhythms, reduced oxygen levels due to abnormal blood flow patterns, impaired small blood vessel function, and worsened heart function following a cardiac arrest.

Congenital adrenal hyperplasia (CAH) is a group of inherited disorders that are caused by autosomal recessive genes. The majority of affected patients, over 90%, have a deficiency of the enzyme 21-hydroxylase. This enzyme is encoded by the 21-hydroxylase gene, which is located on chromosome 6p21 within the HLA histocompatibility complex. The second most common cause of CAH is a deficiency of the enzyme 11-beta-hydroxylase. The condition is rare, with an incidence of approximately 1 in 500 births in the UK. It is more prevalent in the offspring of consanguineous marriages.

The deficiency of 21-hydroxylase leads to a deficiency of cortisol and/or aldosterone, as well as an excess of precursor steroids. As a result, there is an increased secretion of ACTH from the anterior pituitary, leading to adrenocortical hyperplasia.

The severity of CAH varies depending on the degree of 21-hydroxylase deficiency. Female infants often exhibit ambiguous genitalia, such as clitoral hypertrophy and labial fusion. Male infants may have an enlarged scrotum and/or scrotal pigmentation. Hirsutism, or excessive hair growth, occurs in 10% of cases.

Boys with CAH often experience a salt-losing adrenal crisis at around 1-3 weeks of age. This crisis is characterized by symptoms such as vomiting, weight loss, floppiness, and circulatory collapse.

The diagnosis of CAH can be made by detecting markedly elevated levels of the metabolic precursor 17-hydroxyprogesterone. Neonatal screening is possible, primarily through the identification of persistently elevated 17-hydroxyprogesterone levels.

In infants presenting with a salt-losing crisis, the following biochemical abnormalities are observed: hyponatremia (low sodium levels), hyperkalemia (high potassium levels), metabolic acidosis, and hypoglycemia.

Boys experiencing a salt-losing crisis will require fluid resuscitation, intravenous dextrose, and intravenous hydrocortisone.

Affected females will require corrective surgery for their external genitalia. However, they have an intact uterus and ovaries and are capable of having children.

The long-term management of both sexes involves lifelong replacement of hydrocortisone (to suppress ACTH levels).

Small cell lung cancer (SCLC) that originates from neuroendocrine tissue has the potential to cause paraneoplastic endocrine syndromes, such as Cushing syndrome. This occurs due to the inappropriate secretion of ectopic adrenocorticotropic hormone (ACTH). In this particular case, it is highly likely that the patient underwent surgery to remove an ACTH-secreting neuroendocrine tumor within the lung.

The tumors associated with the production of ectopic ACTH are as follows:
– SCLC – 50%
– Bronchial carcinoid tumors – 10%
– Thymic carcinoma – 10%
– Pancreatic islet cell tumors – 5%
– Phaeochromocytoma – 5%
– Medullary carcinoma – 5%

When ectopic ACTH-secreting tumors are present, the typical signs and symptoms of Cushing syndrome may be minimal. The onset of symptoms can be sudden, especially in rapidly growing SCLCs. The typical biochemical profile observed in these cases includes elevated sodium levels, low potassium levels, and metabolic alkalosis.

The body’s homeostatic mechanism will attempt to compensate for the elevated sodium levels by lowering them. However, after the tumor is removed, a paradoxical period of hyponatremia may occur during the postoperative period. This hyponatremia gradually normalizes until the sodium levels reach a normal range once again.

Neisseria gonorrhoeae is a type of bacteria that causes the sexually transmitted infection known as gonorrhoea. It is a Gram-negative diplococcus, meaning it appears as pairs of bacteria under a microscope. This infection is most commonly seen in individuals between the ages of 15 and 35, and it is primarily transmitted through sexual contact. One important characteristic of Neisseria gonorrhoeae is its ability to undergo antigenic variation, which means that recovering from an infection does not provide immunity and reinfection is possible.

When Neisseria gonorrhoeae infects the body, it first attaches to the genitourinary epithelium using pili, which are hair-like structures on the surface of the bacteria. It then invades the epithelial layer and triggers a local acute inflammatory response. In men, the clinical features of gonorrhoea often include urethritis (inflammation of the urethra) in about 80% of cases, dysuria (painful urination) in around 50% of cases, and mucopurulent discharge. Rectal infection may also occur, usually without symptoms, but it can cause anal discharge. Pharyngitis, or inflammation of the throat, is usually asymptomatic in men.

In women, the clinical features of gonorrhoea commonly include vaginal discharge in about 50% of cases, lower abdominal pain in around 25% of cases, dysuria in 10-15% of cases, and pelvic/lower abdominal tenderness in less than 5% of cases. Endocervical discharge and/or bleeding may also be present. Similar to men, rectal infection is usually asymptomatic but can cause anal discharge, and pharyngitis is usually asymptomatic in women as well.

Complications of Neisseria gonorrhoeae infection can be serious and include pelvic inflammatory disease (PID) in women, epididymo-orchitis or prostatitis in men, arthritis, dermatitis, pericarditis and/or myocarditis, hepatitis, and meningitis.

To diagnose gonorrhoea, samples of pus from the urethra, cervix, rectum, or throat should be collected and promptly sent to the laboratory in specialized transport medium. Traditionally, diagnosis has been made using Gram-stain and culture techniques, but newer PCR testing methods are becoming more commonly used.

In this case, a 70-year-old male who recently underwent aortic valve replacement is presenting with symptoms of fever, fatigue, and overall malaise. Upon examination, splinter hemorrhages are observed on the patient’s fingernails, which raises suspicion of infective endocarditis. Given the patient’s history and symptoms, the most likely causative organism in this particular case is Staphylococcus.

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.

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

Further Reading:

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

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

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

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

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

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 collateral 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 use of trimethoprim during the first trimester of pregnancy is linked to a higher risk of neural tube defects due to its interference with folate. If it is not possible to use an alternative antibiotic, it is recommended that pregnant women taking trimethoprim also take high-dose folic acid. However, the use of trimethoprim during the second and third trimesters of pregnancy is considered safe.

Here is a list outlining the commonly encountered drugs that have adverse effects during pregnancy:

ACE inhibitors (e.g. ramipril): If given in the second and third trimesters, they can cause hypoperfusion, renal failure, and the oligohydramnios sequence.

Aminoglycosides (e.g. gentamicin): They can cause ototoxicity and deafness.

Aspirin: High doses can lead to first-trimester abortions, delayed onset labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. However, low doses (e.g. 75 mg) do not pose significant risks.

Benzodiazepines (e.g. diazepam): When given late in pregnancy, they can cause respiratory depression and a neonatal withdrawal syndrome.

Calcium-channel blockers: If given in the first trimester, they can cause phalangeal abnormalities. If given in the second and third trimesters, they can lead to fetal growth retardation.

Carbamazepine: It can cause haemorrhagic disease of the newborn and neural tube defects.

Chloramphenicol: It can cause grey baby syndrome.

Corticosteroids: If given in the first trimester, they may cause orofacial clefts.

Danazol: If given in the first trimester, it can cause masculinization of the female fetuses genitals.

Finasteride: Pregnant women should avoid handling finasteride as crushed or broken tablets can be absorbed through the skin and affect male sex organ development.

Haloperidol: If given in the first trimester, it may cause limb malformations. If given in the third trimester, there is an increased risk of extrapyramidal symptoms in the neonate.

Heparin: It can cause maternal bleeding and thrombocytopenia.

Isoniazid: It can lead to maternal liver damage and neuropathy and seizures in the neonate.

Patients diagnosed with ulcerative colitis face a significantly heightened risk of developing colon cancer. It is crucial for these individuals, especially those with severe or extensive disease, to undergo regular monitoring to detect any potential signs of colon cancer. The risk of developing colon cancer increases as the duration of ulcerative colitis progresses. After 10 years, the risk stands at 1 in 50. After 20 years, the risk increases to 1 in 12. And after 30 years, the risk further rises to 1 in 6. While Crohn’s disease also carries a risk of colonic carcinoma, it is comparatively smaller than that associated with ulcerative colitis.

Scleroderma disorders are a group of connective tissue disorders that affect multiple systems in the body. These disorders are characterized by damage to endothelial cells, oxidative stress, inflammation around blood vessels, and the activation of fibroblasts leading to fibrosis. Autoantibodies also play a significant role in the development of these disorders.

Scleroderma, which refers to thickened skin, can also involve internal organs, leading to a condition called systemic sclerosis. Systemic sclerosis can be classified into two types: limited cutaneous involvement and diffuse involvement. An example of limited cutaneous involvement is CREST syndrome.

CREST syndrome is characterized by several key features. These include the presence of subcutaneous calcifications known as calcinosis, Raynaud’s phenomenon which can cause reduced blood flow to the fingers and other organs, oesophageal dysmotility resulting in difficulty swallowing or painful swallowing, sclerodactyly which is the thickening and tightening of the skin on the fingers and toes, and telangiectasia which is the abnormal dilation of small blood vessels.

In the case of the patient mentioned in this question, they present with progressive dysphagia and Raynaud’s phenomenon. Physical examination reveals sclerodactyly and telangiectasia. These findings strongly suggest a diagnosis of systemic sclerosis with limited cutaneous involvement. The most specific autoantibody associated with this condition is anti-centromere.

In cases of anaphylaxis, it is important to administer non-sedating antihistamines after adrenaline administration and initial resuscitation. Previous guidelines recommended the use of chlorpheniramine and hydrocortisone as third line treatments, but the 2021 guidelines have removed this recommendation. Corticosteroids are no longer advised. Instead, it is now recommended to use non-sedating antihistamines such as cetirizine, loratadine, and fexofenadine, as alternatives to the sedating antihistamine chlorpheniramine. The top priority treatments for anaphylaxis are adrenaline, oxygen, and fluids. The Resuscitation Council advises that administration of non-sedating antihistamines should occur after the initial resuscitation.

Further Reading:

Anaphylaxis is a severe and life-threatening hypersensitivity reaction that can have sudden onset and progression. It is characterized by skin or mucosal changes and can lead to life-threatening airway, breathing, or circulatory problems. Anaphylaxis can be allergic or non-allergic in nature.

In allergic anaphylaxis, there is an immediate hypersensitivity reaction where an antigen stimulates the production of IgE antibodies. These antibodies bind to mast cells and basophils. Upon re-exposure to the antigen, the IgE-covered cells release histamine and other inflammatory mediators, causing smooth muscle contraction and vasodilation.

Non-allergic anaphylaxis occurs when mast cells degrade due to a non-immune mediator. The clinical outcome is the same as in allergic anaphylaxis.

The management of anaphylaxis is the same regardless of the cause. Adrenaline is the most important drug and should be administered as soon as possible. The recommended doses for adrenaline vary based on age. Other treatments include high flow oxygen and an IV fluid challenge. Corticosteroids and chlorpheniramine are no longer recommended, while non-sedating antihistamines may be considered as third-line treatment after initial stabilization of airway, breathing, and circulation.

Common causes of anaphylaxis include food (such as nuts, which is the most common cause in children), drugs, and venom (such as wasp stings). Sometimes it can be challenging to determine if a patient had a true episode of anaphylaxis. In such cases, serum tryptase levels may be measured, as they remain elevated for up to 12 hours following an acute episode of anaphylaxis.

The Resuscitation Council (UK) provides guidelines for the management of anaphylaxis, including a visual algorithm that outlines the recommended steps for treatment.

The Fraser guidelines pertain to the guidelines established by Lord Fraser during the Gillick case in 1985. These guidelines specifically address the provision of contraceptive advice to individuals under the age of 16. According to the Fraser guidelines, a doctor may proceed with providing advice and treatment if they are satisfied with the following criteria:

1. The individual (despite being under 16 years old) possesses a sufficient understanding of the advice being given.
2. The doctor is unable to convince the individual to inform their parents or allow the doctor to inform the parents about seeking contraceptive advice.
3. The individual is likely to engage in sexual intercourse, regardless of whether they receive contraceptive treatment.
4. Without contraceptive advice or treatment, the individual’s physical and/or mental health is likely to deteriorate.
5. The doctor deems it in the individual’s best interests to provide contraceptive advice, treatment, or both without parental consent.

In summary, the Fraser guidelines outline the conditions under which a doctor can offer contraceptive advice to individuals under 16 years old, ensuring their well-being and best interests are taken into account.

A surgical cricothyroidotomy is a procedure performed in emergency situations to secure the airway by making an incision in the cricothyroid membrane. It is also known as an emergency surgical airway (ESA) and is typically done when intubation and oxygenation are not possible.

There are certain conditions in which a surgical cricothyroidotomy should not be performed. These include patients who are under 12 years old, those with laryngeal fractures or pre-existing or acute laryngeal pathology, individuals with tracheal transection and retraction of the trachea into the mediastinum, and cases where the anatomical landmarks are obscured due to trauma.

The procedure is carried out in the following steps:
1. Gathering and preparing the necessary equipment.
2. Positioning the patient on their back with the neck in a neutral position.
3. Sterilizing the patient’s neck using antiseptic swabs.
4. Administering local anesthesia, if time permits.
5. Locating the cricothyroid membrane, which is situated between the thyroid and cricoid cartilage.
6. Stabilizing the trachea with the left hand until it can be intubated.
7. Making a transverse incision through the cricothyroid membrane.
8. Inserting the scalpel handle into the incision and rotating it 90°. Alternatively, a haemostat can be used to open the airway.
9. Placing a properly-sized, cuffed endotracheal tube (usually a size 5 or 6) into the incision, directing it into the trachea.
10. Inflating the cuff and providing ventilation.
11. Monitoring for chest rise and auscultating the chest to ensure adequate ventilation.
12. Securing the airway to prevent displacement.

Potential complications of a surgical cricothyroidotomy include aspiration of blood, creation of a false passage into the tissues, subglottic stenosis or edema, laryngeal stenosis, hemorrhage or hematoma formation, laceration of the esophagus or trachea, mediastinal emphysema, and vocal cord paralysis or hoarseness.

Anticholinergic drugs have been found to worsen cognitive impairment in individuals with dementia. Certain commonly prescribed medications are associated with a higher anticholinergic burden, which can lead to increased cognitive decline. Examples of drugs with high anticholinergic potency include tricyclic antidepressants like amitriptyline hydrochloride, paroxetine, first-generation antihistamines such as chlorpheniramine maleate and promethazine hydrochloride, certain antipsychotics like olanzapine, clozapine, and quetiapine, urinary antispasmodics like solifenacin, oxybutynin, and tolterodine, and antimuscarinics like ipratropium, tiotropium, atropine, and cyclopentolate. However, it’s important to note that rivastigmine and memantine are recommended as first-line treatments for Alzheimer’s and DLB, while haloperidol, despite being an antipsychotic, has low anticholinergic potency.

Further Reading:

Dementia is a progressive and irreversible clinical syndrome characterized by cognitive and behavioral symptoms. These symptoms include memory loss, impaired reasoning and communication, personality changes, and reduced ability to carry out daily activities. The decline in cognition affects multiple domains of intellectual functioning and is not solely due to normal aging.

To diagnose dementia, a person must have impairment in at least two cognitive domains that significantly impact their daily activities. This impairment cannot be explained by delirium or other major psychiatric disorders. Early-onset dementia refers to dementia that develops before the age of 65.

The most common cause of dementia is Alzheimer’s disease, accounting for 50-75% of cases. Other causes include vascular dementia, dementia with Lewy bodies, and frontotemporal dementia. Less common causes include Parkinson’s disease dementia, Huntington’s disease, prion disease, and metabolic and endocrine disorders.

There are several risk factors for dementia, including age, mild cognitive impairment, genetic predisposition, excess alcohol intake, head injury, depression, learning difficulties, diabetes, obesity, hypertension, smoking, Parkinson’s disease, low social engagement, low physical activity, low educational attainment, hearing impairment, and air pollution.

Assessment of dementia involves taking a history from the patient and ideally a family member or close friend. The person’s current level of cognition and functional capabilities should be compared to their baseline level. Physical examination, blood tests, and cognitive assessment tools can also aid in the diagnosis.

Differential diagnosis for dementia includes normal age-related memory changes, mild cognitive impairment, depression, delirium, vitamin deficiencies, hypothyroidism, adverse drug effects, normal pressure hydrocephalus, and sensory deficits.

Management of dementia involves a multi-disciplinary approach that includes non-pharmacological and pharmacological measures. Non-pharmacological interventions may include driving assessment, modifiable risk factor management, and non-pharmacological therapies to promote cognition and independence. Drug treatments for dementia should be initiated by specialists and may include acetylcholinesterase inhibitors, memantine, and antipsychotics in certain cases.

In summary, dementia is a progressive and irreversible syndrome characterized by cognitive and behavioral symptoms. It has various causes and risk factors, and its management involves a multi-disciplinary approach.

Flumazenil is a specific antagonist for benzodiazepines that can be beneficial in certain situations. It acts quickly, taking less than 1 minute to take effect, but its effects are short-lived and only last for less than 1 hour. The recommended dosage is 200 μg every 1-2 minutes, with a maximum dose of 3mg per hour.

It is important to avoid using Flumazenil if the patient is dependent on benzodiazepines or is taking tricyclic antidepressants. This is because it can trigger a withdrawal syndrome in these individuals, potentially leading to seizures or cardiac arrest.

Altitude sickness is usually experienced at altitudes above 2,500 meters (8,000 ft), although some individuals may be affected at lower altitudes. It is important to note that climbers in the UK, where the highest peak is Ben Nevis at 1,345 meters, do not need to worry about altitude sickness.

Further Reading:

High Altitude Illnesses

Altitude & Hypoxia:
– As altitude increases, atmospheric pressure decreases and inspired oxygen pressure falls.
– Hypoxia occurs at altitude due to decreased inspired oxygen.
– At 5500m, inspired oxygen is approximately half that at sea level, and at 8900m, it is less than a third.

Acute Mountain Sickness (AMS):
– AMS is a clinical syndrome caused by hypoxia at altitude.
– Symptoms include headache, anorexia, sleep disturbance, nausea, dizziness, fatigue, malaise, and shortness of breath.
– Symptoms usually occur after 6-12 hours above 2500m.
– Risk factors for AMS include previous AMS, fast ascent, sleeping at altitude, and age <50 years old.
– The Lake Louise AMS score is used to assess the severity of AMS.
– Treatment involves stopping ascent, maintaining hydration, and using medication for symptom relief.
– Medications for moderate to severe symptoms include dexamethasone and acetazolamide.
– Gradual ascent, hydration, and avoiding alcohol can help prevent AMS.

High Altitude Pulmonary Edema (HAPE):
– HAPE is a progression of AMS but can occur without AMS symptoms.
– It is the leading cause of death related to altitude illness.
– Risk factors for HAPE include rate of ascent, intensity of exercise, absolute altitude, and individual susceptibility.
– Symptoms include dyspnea, cough, chest tightness, poor exercise tolerance, cyanosis, low oxygen saturations, tachycardia, tachypnea, crepitations, and orthopnea.
– Management involves immediate descent, supplemental oxygen, keeping warm, and medication such as nifedipine.

High Altitude Cerebral Edema (HACE):
– HACE is thought to result from vasogenic edema and increased vascular pressure.
– It occurs 2-4 days after ascent and is associated with moderate to severe AMS symptoms.
– Symptoms include headache, hallucinations, disorientation, confusion, ataxia, drowsiness, seizures, and manifestations of raised intracranial pressure.
– Immediate descent is crucial for management, and portable hyperbaric therapy may be used if descent is not possible.
– Medication for treatment includes dexamethasone and supplemental oxygen. Acetazolamide is typically used for prophylaxis.

Discitis is an infection that affects the space between the intervertebral discs in the spine. This condition can have serious consequences, including the formation of abscesses and sepsis. The most common cause of discitis is usually Staphylococcus aureus, but other organisms like Streptococcus viridans and Pseudomonas aeruginosa may be responsible in certain cases, especially in immunocompromised individuals and intravenous drug users. Gram-negative organisms like Escherichia coli and Mycobacterium tuberculosis can also cause discitis, particularly in cases of Pott’s disease.

There are several risk factors that increase the likelihood of developing discitis. These include having undergone spinal surgery (which occurs in about 1-2% of patients post-operatively), having an immunodeficiency, being an intravenous drug user, being under the age of eight, having diabetes mellitus, or having a malignancy.

The typical symptoms of discitis include back or neck pain (which occurs in over 90% of cases), pain that often wakes the patient from sleep, fever (present in 60-70% of cases), and neurological deficits (which can occur in up to 50% of cases). In children, a refusal to walk may also be a symptom.

When diagnosing discitis, magnetic resonance imaging (MRI) is the preferred imaging modality due to its high sensitivity and specificity. It is important to image the entire spine, as discitis often affects multiple levels. Plain radiographs are not very sensitive to the early changes of discitis and may appear normal for 2-4 weeks. Computed tomography (CT) scanning is also not very sensitive in detecting discitis.

Treatment for discitis involves hospital admission for intravenous antibiotics. Before starting the antibiotics, it is recommended to send three sets of blood cultures and a full set of blood tests, including a C-reactive protein (CRP) test, to the laboratory.

A typical antibiotic regimen for discitis would include intravenous flucloxacillin 2 g every 6 hours as the first-line treatment if there is no penicillin allergy. Intravenous vancomycin may be used if the infection was acquired in the hospital, if there is a high risk of methicillin-resistant Staphylococcus aureus (MRSA) infection, or if there is a documented penicillin allergy.

An overdose of aspirin often leads to a combination of respiratory alkalosis and metabolic acidosis. Initially, the stimulation of the respiratory center causes hyperventilation and results in respiratory alkalosis. However, as the overdose progresses, the direct acidic effects of aspirin cause an increase in the anion gap and metabolic acidosis.

Here is a summary of common causes for different acid-base disorders:

Respiratory alkalosis can be caused by hyperventilation due to factors such as anxiety, pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, and the early stages of aspirin overdose.

Respiratory acidosis can occur in individuals with chronic obstructive pulmonary disease (COPD), life-threatening asthma, pulmonary edema, sedative drug overdose (such as opioids or benzodiazepines), neuromuscular diseases, and obesity.

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

Metabolic acidosis with a raised anion gap can result from conditions such as lactic acidosis (caused by factors like hypoxemia, shock, sepsis, or tissue infarction), ketoacidosis (associated with diabetes, starvation, or excessive alcohol consumption), renal failure, and poisoning (including the late stages of aspirin overdose, methanol or ethylene glycol ingestion).

Metabolic acidosis with a normal anion gap can be seen in renal tubular acidosis, diarrhea, ammonium chloride ingestion, and adrenal insufficiency.

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.

Narrow QRS complex tachycardia is a term used to describe a fast heart rhythm with a pulse rate over 100 bpm and a QRS duration shorter than 120 ms.

Further Reading:

Supraventricular tachycardia (SVT) is a type of tachyarrhythmia that originates from the atria or above the bundle of His in the heart. It includes all atrial and junctional tachycardias, although atrial fibrillation is often considered separately. SVT typically produces a narrow QRS complex tachycardia on an electrocardiogram (ECG), unless there is an underlying conduction abnormality below the atrioventricular (AV) node. Narrow complex tachycardias are considered SVTs, while some broad complex tachycardias can also be SVTs with co-existent conduction delays.

SVT can be classified into three main subtypes based on where it arises: re-entrant accessory circuits (the most common type), atrial tachycardias, and junctional tachycardias. The most common SVTs are AVNRT (AV nodal re-entry tachycardia) and AVRT (AV re-entry tachycardia), which arise from accessory circuits within the heart. AVNRT involves an accessory circuit within the AV node itself, while AVRT involves an accessory pathway between the atria and ventricles that allows additional electrical signals to trigger the AV node.

Atrial tachycardias originate from abnormal foci within the atria, except for the SA node, AV node, or accessory pathway. Junctional tachycardias arise in the AV junction. The ECG features of SVTs vary depending on the type. Atrial tachycardias may have abnormal P wave morphology, an isoelectric baseline between P waves (in atrial flutter), and inverted P waves in certain leads. AVNRT may show pseudo R waves in V1 or pseudo S waves in certain leads, with an RP interval shorter than the PR interval. AVRT (WPW) may exhibit a delta wave on a resting ECG and retrograde P waves in the ST segment, with an RP interval shorter than the PR interval. Junctional tachycardias may have retrograde P waves before, during, or after the QRS complex, with inverted P waves in certain leads and upright P waves in others.

Treatment of SVT follows the 2021 resuscitation council algorithm for tachycardia with a pulse. The algorithm provides guidelines for managing stable patients with SVT.

A massive haemothorax occurs when more than 1500 mL of blood, which is about 1/3 of the patient’s blood volume, rapidly accumulates in the chest cavity. The classic signs of a massive haemothorax include decreased chest expansion, decreased breath sounds, and dullness to percussion. Both tension pneumothorax and massive haemothorax can cause decreased breath sounds, but they can be differentiated through percussion. Hyperresonance indicates tension pneumothorax, while dullness suggests a massive haemothorax.

The first step in managing a massive haemothorax is to simultaneously restore blood volume and decompress the chest cavity by inserting a chest drain. In most cases, the bleeding in a haemothorax has already stopped by the time management begins, and simple drainage is sufficient. It is important to use a chest drain of adequate size (preferably 36F) to ensure effective drainage of the haemothorax without clotting.

If 1500 mL of blood is immediately drained or if the rate of ongoing blood loss exceeds 200 mL per hour for 2-4 hours, early thoracotomy should be considered.

If a polytrauma patient with a penetrating chest injury has an expanding cardiac tamponade that is left untreated, it can potentially lead to pulseless electrical activity.

Further Reading:

Cardiac tamponade, also known as pericardial tamponade, occurs when fluid accumulates in the pericardial sac and compresses the heart, leading to compromised blood flow. Classic clinical signs of cardiac tamponade include distended neck veins, hypotension, muffled heart sounds, and pulseless electrical activity (PEA). Diagnosis is typically done through a FAST scan or an echocardiogram.

Management of cardiac tamponade involves assessing for other injuries, administering IV fluids to reduce preload, performing pericardiocentesis (inserting a needle into the pericardial cavity to drain fluid), and potentially performing a thoracotomy. It is important to note that untreated expanding cardiac tamponade can progress to PEA cardiac arrest.

Pericardiocentesis can be done using the subxiphoid approach or by inserting a needle between the 5th and 6th intercostal spaces at the left sternal border. Echo guidance is the gold standard for pericardiocentesis, but it may not be available in a resuscitation situation. Complications of pericardiocentesis include ST elevation or ventricular ectopics, myocardial perforation, bleeding, pneumothorax, arrhythmia, acute pulmonary edema, and acute ventricular dilatation.

It is important to note that pericardiocentesis is typically used as a temporary measure until a thoracotomy can be performed. Recent articles published on the RCEM learning platform suggest that pericardiocentesis has a low success rate and may delay thoracotomy, so it is advised against unless there are no other options available.

Cauda equina syndrome (CES) is a rare but serious complication that can occur when a disc ruptures. This happens when the material from the disc is pushed into the spinal canal and puts pressure on the bundle of nerves in the lower back and sacrum. As a result, individuals may experience loss of control over their bladder and bowel functions.

There are certain red flags that may indicate the presence of CES. These include experiencing sciatica on both sides of the body, having severe or worsening neurological issues in both legs (such as significant weakness in knee extension, ankle eversion, or foot dorsiflexion), difficulty starting urination or a decreased sensation of urinary flow, loss of sensation in the rectum, experiencing numbness or tingling in the perianal, perineal, or genital areas (also known as saddle anesthesia or paresthesia), and having a lax anal sphincter.

Conus medullaris syndrome (CMS) is a condition that affects the conus medullaris, which is located above the cauda equina at the T12-L2 level. Unlike CES, CMS primarily causes back pain and may have less noticeable nerve root pain. The main symptoms of CMS are urinary retention and constipation.

To confirm a diagnosis of CES and determine the level of compression and any underlying causes, an MRI scan is considered the gold-standard investigation. In cases where an MRI is not possible or contraindicated, a CT myelogram or standard CT scans can be helpful. However, plain radiographs have limited value and may only show significant degenerative or traumatic bone diseases.

The mast cell tryptase test, also known as the tryptase test, is a valuable tool for detecting mast cell activation and confirming the diagnosis of anaphylaxis in cases where there is uncertainty. Tryptase is the primary protein found in mast cells. During anaphylaxis, mast cells release their contents, leading to an increase in blood tryptase levels. Typically, these levels start to rise approximately 30 minutes after symptoms begin, reach their peak at 1-2 hours, and return to normal within 6-8 hours.

For optimal results, it is recommended to collect three timed samples. The first sample should be taken as soon as possible after resuscitation efforts have commenced. The second sample should be obtained 1-2 hours after the onset of symptoms. Lastly, a third sample should be collected at the 24-hour mark to establish a baseline level.

While skin allergy tests, like the patch test, and blood tests for specific IgE can help identify the trigger of an allergic reaction, they alone cannot confirm the occurrence of anaphylaxis. The mast cell tryptase test, on the other hand, provides valuable information in confirming the diagnosis.

During the third trimester of pregnancy, the use of selective serotonin reuptake inhibitors (SSRIs) has been associated with a discontinuation syndrome and persistent pulmonary hypertension of the newborn. It is important to be aware of the adverse effects of various drugs during pregnancy. For example, ACE inhibitors like ramipril, if given in the second and third trimester, can cause hypoperfusion, renal failure, and the oligohydramnios sequence. Aminoglycosides such as gentamicin can lead to ototoxicity and deafness. 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 (e.g., 75 mg) do not pose significant risks. Late administration of benzodiazepines like diazepam during pregnancy can cause respiratory depression and a neonatal withdrawal syndrome. Calcium-channel blockers, if given in the first trimester, may cause phalangeal abnormalities, while their use in the second and third trimester can lead to fetal growth retardation. Carbamazepine has been associated with hemorrhagic disease of the newborn and neural tube defects. Chloramphenicol can cause grey baby syndrome. Corticosteroids, if given in the first trimester, may cause orofacial clefts. Danazol, if administered in the first trimester, can result in masculinization of the female fetuses genitals. Pregnant women should avoid handling crushed or broken tablets of finasteride as it can be absorbed through the skin and affect male sex organ development. Haloperidol, if given in the first trimester, may cause limb malformations, while its use in the third trimester increases the risk of extrapyramidal symptoms in the neonate. Heparin can lead to maternal bleeding and thrombocytopenia. Isoniazid can cause maternal liver damage and neuropathy and seizures in the neonate. Isotretinoin carries a high risk of teratogenicity, including multiple congenital malformations, spontaneous abortion, and intellectual disability. The use of lithium in the first trimester increases the risk of fetal cardiac malformations, while its use in the second and third trimesters can result in hypotonia, lethargy, feeding problems, hypothyroidism, goiter, and nephrogenic diabetes insipidus.

Instances of local anaesthetic systemic toxicity (LAST) should be promptly reported to the National Patient Safety Agency (NPSA). Additionally, it is advisable to report any adverse drug reactions to the Medicines and Healthcare products Regulatory Agency (MHRA) through their yellow card scheme. Please refer to the follow-up section in the notes for further details.

Further Reading:

Local anaesthetics, such as lidocaine, bupivacaine, and prilocaine, are commonly used in the emergency department for topical or local infiltration to establish a field block. Lidocaine is often the first choice for field block prior to central line insertion. These anaesthetics work by blocking sodium channels, preventing the propagation of action potentials.

However, local anaesthetics can enter the systemic circulation and cause toxic side effects if administered in high doses. Clinicians must be aware of the signs and symptoms of local anaesthetic systemic toxicity (LAST) and know how to respond. Early signs of LAST include numbness around the mouth or tongue, metallic taste, dizziness, visual and auditory disturbances, disorientation, and drowsiness. If not addressed, LAST can progress to more severe symptoms such as seizures, coma, respiratory depression, and cardiovascular dysfunction.

The management of LAST is largely supportive. Immediate steps include stopping the administration of local anaesthetic, calling for help, providing 100% oxygen and securing the airway, establishing IV access, and controlling seizures with benzodiazepines or other medications. Cardiovascular status should be continuously assessed, and conventional therapies may be used to treat hypotension or arrhythmias. Intravenous lipid emulsion (intralipid) may also be considered as a treatment option.

If the patient goes into cardiac arrest, CPR should be initiated following ALS arrest algorithms, but lidocaine should not be used as an anti-arrhythmic therapy. Prolonged resuscitation may be necessary, and intravenous lipid emulsion should be administered. After the acute episode, the patient should be transferred to a clinical area with appropriate equipment and staff for further monitoring and care.

It is important to report cases of local anaesthetic toxicity to the appropriate authorities, such as the National Patient Safety Agency in the UK or the Irish Medicines Board in the Republic of Ireland. Additionally, regular clinical review should be conducted to exclude pancreatitis, as intravenous lipid emulsion can interfere with amylase or lipase assays.

HELLP syndrome is a condition that occurs in approximately 0.5% of pregnancies. It is characterized by haemolysis, elevated liver enzymes, and a low platelet count. While it typically occurs in the late third trimester, it has also been reported in the late second trimester. Around 33% of patients with HELLP syndrome will present shortly after giving birth.

The initial symptoms of HELLP syndrome can be vague and include nausea, headaches, malaise, and pain in the upper right quadrant of the abdomen. Upon examination, raised blood pressure, proteinuria, and edema may be observed. Further investigations may reveal haemolysis on a blood film, elevated liver enzymes, low platelets, raised LDH, and raised bilirubin.

Delivery of the baby is the main treatment for HELLP syndrome. However, complications can arise, such as disseminated intravascular coagulation (DIC), renal failure, liver failure, and pulmonary edema. It is crucial to tightly control blood pressure, and magnesium sulfate is often used to reduce the risk of progression to eclampsia. If DIC occurs, treatment with fresh frozen plasma is necessary.

Without prompt recognition, approximately 25% of individuals with HELLP syndrome may experience severe complications, including placental abruption, liver failure, retinal detachment, and renal failure. With treatment, the mortality rate for the mother is around 1%, while the mortality rate for the baby ranges from 5-10%, depending on the gestational age at the time of delivery.

Antihistamines do not help in treating the life-threatening aspects of anaphylaxis and should not be used instead of adrenaline. However, they can be used to relieve symptoms such as skin reactions and itching once the patient’s condition has stabilized. The appropriate dose of cetirizine for children between the ages of 2 and 6 is 2.5-5 mg. It is important to note that chlorpheniramine is no longer recommended. The recommended doses of oral cetirizine for different age groups are as follows: less than 2 years – 250 micrograms/kg, 2-6 years – 2.5-5 mg, 6-11 years – 5-10 mg, 12 years and older – 10-20 mg.

Further Reading:

Anaphylaxis is a severe and life-threatening allergic reaction that affects the entire body. It is characterized by a rapid onset and can lead to difficulty breathing, low blood pressure, and loss of consciousness. In paediatrics, anaphylaxis is often caused by food allergies, with nuts being the most common trigger. Other causes include drugs and insect venom, such as from a wasp sting.

When treating anaphylaxis, time is of the essence and there may not be enough time to look up medication doses. Adrenaline is the most important drug in managing anaphylaxis and should be administered as soon as possible. The recommended doses of adrenaline vary based on the age of the child. For children under 6 months, the dose is 150 micrograms, while for children between 6 months and 6 years, the dose remains the same. For children between 6 and 12 years, the dose is increased to 300 micrograms, and for adults and children over 12 years, the dose is 500 micrograms. Adrenaline can be repeated every 5 minutes if necessary.

The preferred site for administering adrenaline is the anterolateral aspect of the middle third of the thigh. This ensures quick absorption and effectiveness of the medication. It is important to follow the Resuscitation Council guidelines for anaphylaxis management, as they have recently been updated.

In some cases, it can be challenging to determine if a patient had a true episode of anaphylaxis. In such cases, serum tryptase levels may be measured, as they remain elevated for up to 12 hours following an acute episode of anaphylaxis. This can help confirm the diagnosis and guide further management.

Overall, prompt recognition and administration of adrenaline are crucial in managing anaphylaxis in paediatrics. Following the recommended doses and guidelines can help ensure the best outcomes for patients experiencing this severe allergic reaction.

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