Here is a revised version of the guidance on the management of bacterial conjunctivitis:

– It is important to inform the patient that most cases of bacterial conjunctivitis will resolve on their own within 5-7 days without any treatment.
– However, if the condition is severe or if there is a need for rapid resolution, topical antibiotics may be prescribed. In some cases, a delayed treatment strategy may be appropriate, and the patient should be advised to start using topical antibiotics if their symptoms have not improved within 3 days.
– There are several options for topical antibiotics, including Chloramphenicol 0.5% drops (to be applied every 2 hours for 2 days, then 4 times daily for 5 days) and Chloramphenicol 1% ointment (to be applied four times daily for 2 days, then twice daily for 5 days). Fusidic acid 1% eye drops can also be used as a second-line treatment, to be applied twice daily for 7 days.
– It is important to note that there is no recommended exclusion period from school, nursery, or childminders for isolated cases of bacterial conjunctivitis. However, some institutions may have their own exclusion policies.
– Provide the patient with written information and explain the red flags that indicate the need for an urgent review.
– Arrange a follow-up appointment to confirm the diagnosis and ensure that the symptoms have resolved.
– If the patient returns with ongoing symptoms, it may be necessary to send swabs for viral PCR (to test for adenovirus and Herpes simplex) and bacterial culture. Empirical topical antibiotics may also be prescribed if they have not been previously given.
– Consider referring the patient to ophthalmology if the symptoms persist for more than 7 to 10 days after initiating treatment.

For more information, you can refer to the NICE Clinical Knowledge Summary on Infective Conjunctivitis.

NICE has emphasized that certain symptoms and signs can indicate specific diseases as the underlying cause of a fever. In the case of meningococcal disease, the presence of a rash that does not fade when pressed upon (non-blanching rash) is particularly suggestive, especially if the child appears unwell, the lesions are larger than 2 mm in diameter (purpura), the capillary refill time is 3 seconds or longer, or there is neck stiffness. 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.

The following provides a summary of common causes for different acid-base disorders.

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, on the other hand, is often associated with chronic obstructive pulmonary disease (COPD), life-threatening asthma, pulmonary edema, sedative drug overdose (such as opiates or benzodiazepines), neuromuscular disease, obesity, or other respiratory conditions.

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 lactic acidosis (such as in cases of hypoxemia, shock, sepsis, or infarction), ketoacidosis (such as in diabetes, starvation, or alcohol excess), renal failure, or poisoning (such as in late stages of aspirin overdose, methanol or ethylene glycol ingestion).

Lastly, metabolic acidosis with a normal anion gap can be a result of conditions like diarrhea, ammonium chloride ingestion, or adrenal insufficiency.

Methaemoglobinaemia is a condition characterized by high levels of haemoglobin with iron in the ferric (Fe3+) state. This occurs when haemoglobin is oxidized from Fe2+ to Fe3+. Normally, NADH methaemoglobin reductase, also known as Cytochrome b5 reductase, regulates this process by transferring electrons from NADH to methaemoglobin, converting it back to haemoglobin. However, if there is a congenital or acquired dysfunction in the NADH methaemoglobin reductase enzyme system, it can lead to elevated levels of haemoglobin with iron in the Fe3+ state. Unfortunately, Fe3+ is unable to bind to haemoglobin.

Further Reading:

Methaemoglobinaemia is a condition where haemoglobin is oxidised from Fe2+ to Fe3+. This process is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin, converting it back to haemoglobin. In healthy individuals, methaemoglobin levels are typically less than 1% of total haemoglobin. However, an increase in methaemoglobin can lead to tissue hypoxia as Fe3+ cannot bind oxygen effectively.

Methaemoglobinaemia can be congenital or acquired. Congenital causes include haemoglobin chain variants (HbM, HbH) and NADH methaemoglobin reductase deficiency. Acquired causes can be due to exposure to certain drugs or chemicals, such as sulphonamides, local anaesthetics (especially prilocaine), nitrates, chloroquine, dapsone, primaquine, and phenytoin. Aniline dyes are also known to cause methaemoglobinaemia.

Clinical features of methaemoglobinaemia include slate grey cyanosis (blue to grey skin coloration), chocolate blood or chocolate cyanosis (brown color of blood), dyspnoea, low SpO2 on pulse oximetry (which often does not improve with supplemental oxygen), and normal PaO2 on arterial blood gas (ABG) but low SaO2. Patients may tolerate hypoxia better than expected. Severe cases can present with acidosis, arrhythmias, seizures, and coma.

Diagnosis of methaemoglobinaemia is made by directly measuring the level of methaemoglobin using a co-oximeter, which is present in most modern blood gas analysers. Other investigations, such as a full blood count (FBC), electrocardiogram (ECG), chest X-ray (CXR), and beta-human chorionic gonadotropin (bHCG) levels (in pregnancy), may be done to assess the extent of the condition and rule out other contributing factors.

Active treatment is required if the methaemoglobin level is above 30% or if it is below 30% but the patient is symptomatic or shows evidence of tissue hypoxia. Treatment involves maintaining the airway and delivering high-flow oxygen, removing the causative agents, treating toxidromes and consider giving IV dextrose 5%.

Mitral stenosis is a condition characterized by a narrowing of the mitral valve, which can lead to various symptoms. One common symptom is a mid-late diastolic murmur, which can be heard during a physical examination. This murmur may also be described as mid-diastolic, late-diastolic, or mid-late diastolic. Additionally, patients with chronic mitral stenosis may not experience any symptoms, and the murmur may only be detected incidentally.

A significant risk associated with mitral stenosis is the development of atrial fibrillation (AF). When AF occurs in patients with mitral stenosis, it can trigger acute pulmonary edema. This happens because the left atrium, which is responsible for pumping blood across the narrowed mitral valve into the left ventricle, needs to generate higher pressure. However, when AF occurs, the atrial contraction becomes inefficient, leading to impaired emptying of the left atrium. This, in turn, causes increased back pressure in the pulmonary circulation.

The elevated pressure in the left atrium and pulmonary circulation can result in the rupture of bronchial veins, leading to the production of pink frothy sputum. This symptom is often observed in patients with mitral stenosis who develop acute pulmonary edema.

Further Reading:

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.

Defibrillation is a procedure used to treat two specific cardiac rhythms, ventricular fibrillation and pulseless ventricular tachycardia. It involves delivering an electrical shock randomly during the cardiac cycle to restore a normal heart rhythm. It is important to note that defibrillation is different from cardioversion, which involves delivering energy synchronized to the QRS complex.

Further Reading:

In the event of an adult experiencing cardiorespiratory arrest, it is crucial for doctors to be familiar with the Advanced Life Support (ALS) algorithm. They should also be knowledgeable about the proper technique for chest compressions, the appropriate rhythms for defibrillation, the reversible causes of arrest, and the drugs used in advanced life support.

During chest compressions, the rate should be between 100-120 compressions per minute, with a depth of compression of 5-6 cm. The ratio of chest compressions to rescue breaths should be 30:2. It is important to change the person giving compressions regularly to prevent fatigue.

There are two shockable ECG rhythms that doctors should be aware of: ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT). These rhythms require defibrillation.

There are four reversible causes of cardiorespiratory arrest, known as the 4 H’s and 4 T’s. The 4 H’s include hypoxia, hypovolemia, hypo or hyperkalemia or metabolic abnormalities, and hypothermia. The 4 T’s include thrombosis (coronary or pulmonary), tension pneumothorax, tamponade, and toxins. Identifying and treating these reversible causes is crucial for successful resuscitation.

When it comes to resus drugs, they are considered of secondary importance during CPR due to the lack of high-quality evidence for their efficacy. However, adrenaline (epinephrine) and amiodarone are the two drugs included in the ALS algorithm. Doctors should be familiar with the dosing, route, and timing of administration for both drugs.

Adrenaline should be administered intravenously at a concentration of 1 in 10,000 (100 micrograms/mL). It should be repeated every 3-5 minutes. Amiodarone is initially given at a dose of 300 mg, either from a pre-filled syringe or diluted in 20 mL of Glucose 5%. If required, an additional dose of 150 mg can be given by intravenous injection. This is followed by an intravenous infusion of 900 mg over 24 hours. The first dose of amiodarone is given after 3 shocks.

Macrolide antibiotics, such as clarithromycin and erythromycin, are widely known to prolong the International Normalized Ratio (INR). Several drugs can increase the potency of warfarin, and the macrolides, along with ciprofloxacin and metronidazole, are the antibiotics that have the most significant impact on enhancing the effect of warfarin.

Further Reading:

Management of High INR with Warfarin

Major Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 5 mg.
– Administer 25-50 u/kg four-factor prothrombin complex concentrate.
– If prothrombin complex concentrate is not available, consider using fresh frozen plasma (FFP).
– Seek medical attention promptly.

INR > 8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR > 8.0 without Bleeding:
– Stop warfarin immediately.
– Administer oral vitamin K 1-5 mg using the intravenous preparation orally.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if any symptoms or concerns arise.

INR 5.0-8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR 5.0-8.0 without Bleeding:
– Withhold 1 or 2 doses of warfarin.
– Reduce subsequent maintenance dose.
– Monitor INR closely and seek medical advice if any concerns arise.

Note: In cases of intracranial hemorrhage, prothrombin complex concentrate should be considered as it is faster acting than fresh frozen plasma (FFP).

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

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

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

Conjunctivitis is the most common reason for red eyes, accounting for about 35% of all eye problems seen in general practice. It occurs when the conjunctiva, the thin layer covering the white part of the eye, becomes inflamed. Conjunctivitis can be caused by an infection or an allergic reaction.

Infective conjunctivitis is inflammation of the conjunctiva caused by a viral, bacterial, or parasitic infection. The most common type of infective conjunctivitis is viral, with adenoviruses being the main culprits. Bacterial conjunctivitis is also common and is usually caused by Streptococcus pneumoniae, Staphylococcus aureus, or Haemophilus influenzae.

The symptoms of infective conjunctivitis include sudden redness of the conjunctiva, discomfort described as a gritty or burning sensation, watering of the eyes, and discharge that may temporarily blurry vision. It can be challenging to differentiate between viral and bacterial conjunctivitis based on symptoms alone.

Here are some key features that can help distinguish between viral and bacterial conjunctivitis:

Features suggestive of viral conjunctivitis:
– Mild to moderate redness of the conjunctiva
– Presence of follicles on the inner surface of the eyelids
– Swelling of the eyelids
– Small, pinpoint bleeding under the conjunctiva
– Pseudomembranes (thin layers of tissue) may form on the inner surface of the eyelids in severe cases, often caused by adenovirus
– Less discharge (usually watery) compared to bacterial conjunctivitis
– Mild to moderate itching
– Symptoms of upper respiratory tract infection and swollen lymph nodes in front of the ears

Features suggestive of bacterial conjunctivitis:
– Purulent or mucopurulent discharge with crusting of the eyelids, which may cause them to stick together upon waking
– Mild or no itching
– Swollen lymph nodes in front of the ears, which are often present in severe bacterial conjunctivitis
– If the discharge is copious and mucopurulent, infection with Neisseria gonorrhoeae should be considered.

By considering these distinguishing features, healthcare professionals can better diagnose and manage cases of conjunctivitis.

Crohn’s disease is characterized by skip lesions, which are not present in ulcerative colitis. Unlike ulcerative colitis, Crohn’s disease causes inflammation throughout the entire thickness of the intestinal wall, not just the mucosa. Interestingly, smoking increases the risk of developing Crohn’s disease but decreases the risk of ulcerative colitis. Additionally, having an appendicectomy before adulthood is believed to protect against ulcerative colitis, whereas it actually increases the risk of developing Crohn’s disease for about 5 years after the surgery.

Further Reading:

Inflammatory bowel disease (IBD) is a chronic condition characterized by inflammation of the intestinal tract and an imbalance of the intestinal microbiota. The two main forms of IBD are Crohn’s disease and ulcerative colitis (UC). In some cases, it is not possible to differentiate between Crohn’s disease and UC, and the term inflammatory bowel disease type-unclassified may be used.

Crohn’s disease is a chronic, relapsing-remitting inflammatory disease that can affect any part of the gastrointestinal tract, from the mouth to the anus. It most commonly involves the ileum and colon. The inflammation in Crohn’s disease affects all layers of the intestinal wall, leading to complications such as strictures, fistulas, and adhesions. Risk factors for developing Crohn’s disease include a family history, smoking, infectious gastroenteritis, appendicectomy, and the use of NSAIDs and oral contraceptive drugs. Symptoms of Crohn’s disease can vary but often include diarrhea, abdominal pain, weight loss, and perianal disease. Extraintestinal features, such as arthritis, erythema nodosum, and uveitis, can also occur.

Ulcerative colitis is a chronic, relapsing-remitting inflammatory disease that primarily affects the large bowel. The inflammation in UC is limited to the intestinal mucosa and does not involve skip lesions like in Crohn’s disease. Risk factors for developing UC include a family history, not smoking, and no appendix. Symptoms of UC include bloody diarrhea, urgency, tenesmus, and abdominal pain. Extraintestinal features, such as arthritis and uveitis, can also occur. Complications of UC include toxic megacolon, bowel obstruction, bowel perforation, strictures, fistula formation, anemia, malnutrition, and colorectal cancer.

Diagnosing IBD involves various investigations, including blood tests, stool microscopy and culture, fecal calprotectin testing, endoscopy with biopsy, and imaging modalities such as CT and MR enterography. The management of Crohn’s disease and UC is complex and may involve corticosteroids, immunosuppressive drugs, biologic therapy, surgery, and nutritional support. Patients with IBD should also be monitored for nutritional deficiencies, colorectal cancer, and osteoporosis.

A peptic ulcer is a condition where there is a hole or defect in the lining of the stomach or duodenum that is larger than 5mm in diameter. If left untreated, there is a risk that the ulcer may perforate, meaning it can create a rupture or tear in the lining. It is important to note that if the defect is smaller than 5mm, it is classified as an erosion rather than an ulcer.

Further Reading:

Peptic ulcer disease (PUD) is a condition characterized by a break in the mucosal lining of the stomach or duodenum. It is caused by an imbalance between factors that promote mucosal damage, such as gastric acid, pepsin, Helicobacter pylori infection, and NSAID drug use, and factors that maintain mucosal integrity, such as prostaglandins, mucus lining, bicarbonate, and mucosal blood flow.

The most common causes of peptic ulcers are H. pylori infection and NSAID use. Other factors that can contribute to the development of ulcers include smoking, alcohol consumption, certain medications (such as steroids), stress, autoimmune conditions, and tumors.

Diagnosis of peptic ulcers involves screening for H. pylori infection through breath or stool antigen tests, as well as upper gastrointestinal endoscopy. Complications of PUD include bleeding, perforation, and obstruction. Acute massive hemorrhage has a case fatality rate of 5-10%, while perforation can lead to peritonitis with a mortality rate of up to 20%.

The symptoms of peptic ulcers vary depending on their location. Duodenal ulcers typically cause pain that is relieved by eating, occurs 2-3 hours after eating and at night, and may be accompanied by nausea and vomiting. Gastric ulcers, on the other hand, cause pain that occurs 30 minutes after eating and may be associated with nausea and vomiting.

Management of peptic ulcers depends on the underlying cause and presentation. Patients with active gastrointestinal bleeding require risk stratification, volume resuscitation, endoscopy, and proton pump inhibitor (PPI) therapy. Those with perforated ulcers require resuscitation, antibiotic treatment, analgesia, PPI therapy, and urgent surgical review.

For stable patients with peptic ulcers, lifestyle modifications such as weight loss, avoiding trigger foods, eating smaller meals, quitting smoking, reducing alcohol consumption, and managing stress and anxiety are recommended. Medication review should be done to stop causative drugs if possible. PPI therapy, with or without H. pylori eradication therapy, is also prescribed. H. pylori testing is typically done using a carbon-13 urea breath test or stool antigen test, and eradication therapy involves a 7-day triple therapy regimen of antibiotics and PPI.

This patient exhibits clinical features that are consistent with the ingestion of a drug that blocks the action of the neurotransmitter acetylcholine in the central and peripheral nervous system. There are several anticholinergic drugs commonly used in clinical practice. Some examples include antihistamines like promethazine and diphenhydramine, typical and atypical antipsychotics such as haloperidol and quetiapine, anticonvulsants like carbamazepine, antidepressants like tricyclic antidepressants, and antispasmodics like hyoscine butylbromide. Other sources of anticholinergic effects can come from plants like datura species and certain mushrooms.

When someone ingests an anticholinergic drug, they may experience a toxidrome, which is characterized by an agitated delirium and various signs of acetylcholine receptor blockade in both the central and peripheral nervous system. The central inhibition leads to an agitated delirium, which is marked by fluctuating mental status, confusion, restlessness, visual hallucinations, picking at objects in the air, mumbling, slurred speech, disruptive behavior, tremor, myoclonus, and in rare cases, coma and seizures. The peripheral inhibition can cause dilated pupils, sinus tachycardia, dry mouth, hot and flushed skin, increased body temperature, urinary retention, and ileus.

In summary, the ingestion of an anticholinergic drug can result in a toxidrome characterized by an agitated delirium and various signs of central and peripheral acetylcholine receptor blockade. It is important to be aware of the potential effects of these drugs and to recognize the clinical features associated with their ingestion.

Loss of reactivity, in contrast to heightened reactivity, is a common trait seen in individuals with depression. The clinical manifestations of depression encompass various symptoms. These include experiencing a persistent low mood, which may fluctuate throughout the day. Another prominent feature is anhedonia, which refers to a diminished ability to experience pleasure. Additionally, individuals with depression often exhibit antipathy, displaying a lack of interest or enthusiasm towards activities or people. Their speech may become slow and have a reduced volume. They may also struggle with maintaining attention and concentration. Furthermore, depression can lead to a decrease in self-esteem, accompanied by thoughts of guilt and worthlessness. Insomnia, particularly early morning waking, is a classic symptom of depression. Other common signs include a decrease in libido, low energy levels, increased fatigue, and a poor appetite resulting in weight loss.

Cauda equina syndrome (CES) is a rare but serious complication that can occur when a disc in the spine ruptures. This happens when the material from the disc is pushed into the spinal canal and puts pressure on a bundle of nerves in the lower back and sacrum. When this happens, it can lead to problems with controlling the bladder and bowels.

There are certain signs that may indicate the presence of CES, which are known as red flags. These include experiencing sciatica on both sides of the body, having a severe or worsening neurological deficit in both legs, such as significant weakness in the muscles that extend the knee, turn the ankle outward, or lift the foot upward. Other red flags include difficulty starting to urinate or a decreased sensation of the flow of urine, a loss of feeling when the rectum is full, a loss of sensation in the perianal, perineal, or genital areas (also known as saddle anesthesia or paresthesia), and a looseness in the anal sphincter muscle.

According to NICE, the presence of certain clinical features in a child between three months and five years old may indicate a urinary tract infection (UTI). These features include vomiting, poor feeding, lethargy, irritability, abdominal pain or tenderness, and urinary frequency or dysuria. For more information on this topic, 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.

Benzodiazepines are commonly prescribed in the UK to help manage symptoms of alcohol withdrawal. Currently, only diazepam and chlordiazepoxide have been approved for this purpose. If you would like to learn more about the NICE pathway for acute alcohol withdrawal or the RCEM syllabus reference, please refer to the provided links. Additionally, information on alcohol and substance misuse can be found in the MHC1 section.

The intravascular volume of an infant is approximately 80 ml/kg. In older children, the intravascular volume is around 70 ml/kg.

Dehydration itself does not lead to death, but shock can. Shock can occur when there is a loss of 20 ml/kg from the intravascular space, while clinical dehydration is only noticeable after total losses of more than 25 ml/kg.

The maintenance fluid requirements for healthy, typical children are summarized in the table below:

Bodyweight:
– First 10 kg: Daily fluid requirement of 100 ml/kg, hourly fluid requirement of 4 ml/kg
– Second 10 kg: Daily fluid requirement of 50 ml/kg, hourly fluid requirement of 2 ml/kg
– Subsequent kg: Daily fluid requirement of 20 ml/kg, hourly fluid requirement of 1 ml/kg

Therefore, this child’s daily maintenance fluid requirement can be calculated as follows:

– First 10 kg: 100 ml/kg = 1000 ml
– Second 10 kg: 50 ml/kg = 500 ml
– Subsequent kg: 20 ml/kg = 40 ml

Total daily maintenance fluid requirement: 1540 ml

Central retinal artery occlusion (CRAO) is characterized by sudden and painless loss of vision in the affected eye. It can occur due to emboli from atheromatous carotid arteries, thrombosis caused by arteriosclerosis or hypertension, or vasospasm resulting from giant cell arteritis. The pupil on the affected side typically shows poor reactivity to light, but the consensual light reaction remains normal. The typical retinal findings in CRAO include a pale retina due to edema, narrowed blood vessels, segmentation of blood columns in arteries (resembling cattle-trucking), and a cherry red spot indicating sparing of the macular center supplied by the underlying choroid. Over several weeks, optic atrophy may develop. Immediate referral to an eye specialist is necessary as CRAO is an ophthalmological emergency.

On the other hand, central retinal vein occlusion (CRVO) leads to painless and unilateral visual loss. The retina in CRVO has a distinct appearance likened to a pizza thrown against a wall. Fundoscopic examination reveals engorged retinal veins, disc edema, multiple flame-shaped hemorrhages, and cotton wool spots.

When dealing with an anaphylactic reaction, it is important to remove the trigger if it is easily accessible. However, it is not realistic to try and remove a peanut that has already been swallowed, and it is advised against attempting to induce vomiting in the patient.

In cases where an anaphylactic reaction has been confirmed, it is crucial to administer 500 micrograms of adrenaline immediately.

Mastoiditis can lead to the development of cranial nerve palsies, specifically affecting the trigeminal (CN V), abducens (CN VI), and facial (CN VII) nerves. This occurs when the infection spreads to the petrous apex of the temporal bone, where these nerves are located. The close proximity of the sixth cranial nerve and the trigeminal ganglion, separated only by the dura mater, can result in inflammation and subsequent nerve damage. Additionally, the facial nerve is at risk as it passes through the mastoid via the facial canal.

Further Reading:

Mastoiditis is an infection of the mastoid air cells, which are located in the mastoid process of the skull. It is usually caused by the spread of infection from the middle ear. The most common organism responsible for mastoiditis is Streptococcus pneumoniae, but other bacteria and fungi can also be involved. The infection can spread to surrounding structures, such as the meninges, causing serious complications like meningitis or cerebral abscess.

Mastoiditis can be classified as acute or chronic. Acute mastoiditis is a rare complication of acute otitis media, which is inflammation of the middle ear. It is characterized by severe ear pain, fever, swelling and redness behind the ear, and conductive deafness. Chronic mastoiditis is usually associated with chronic suppurative otitis media or cholesteatoma and presents with recurrent episodes of ear pain, headache, and fever.

Mastoiditis is more common in children, particularly those between 6 and 13 months of age. Other risk factors include immunocompromised patients, those with intellectual impairment or communication difficulties, and individuals with cholesteatoma.

Diagnosis of mastoiditis involves a physical examination, blood tests, ear swab for culture and sensitivities, and imaging studies like contrast-enhanced CT or MRI. Treatment typically involves referral to an ear, nose, and throat specialist, broad-spectrum intravenous antibiotics, pain relief, and myringotomy (a procedure to drain fluid from the middle ear).

Complications of mastoiditis are rare but can be serious. They include intracranial abscess, meningitis, subperiosteal abscess, neck abscess, venous sinus thrombosis, cranial nerve palsies, hearing loss, labyrinthitis, extension to the zygoma, and carotid artery arteritis. However, most patients with mastoiditis have a good prognosis and do not experience long-term ear problems.

Benign paroxysmal positional vertigo (BPPV) occurs when there is dysfunction in the inner ear. This dysfunction causes the otoliths, which are located in the utricle, to become dislodged from their normal position and migrate into one of the semicircular canals over time. As a result, these detached otoliths continue to move even after head movement has stopped, leading to vertigo due to the conflicting sensation of ongoing movement with other sensory inputs.

While the majority of BPPV cases have no identifiable cause (idiopathic), approximately 40% of cases can be attributed to factors such as head injury, spontaneous labyrinthine degeneration, post-viral illness, middle ear surgery, or chronic middle ear disease.

The main clinical features of BPPV include symptoms that are provoked by head movement, rolling over, and upward gaze. These episodes are typically brief, lasting less than 5 minutes, and are often worse in the mornings. Unlike other inner ear disorders, BPPV does not cause hearing loss or tinnitus. Nausea is a common symptom, while vomiting is rare. The Dix-Hallpike test can be used to confirm the diagnosis of BPPV.

It is important to note that vestibular suppressant medications have not been proven to be beneficial in managing BPPV. These medications do not improve symptoms or reduce the duration of the disease.

The treatment of choice for BPPV is the Epley manoeuvre. This maneuver aims to reposition the dislodged otoliths back into the utricles from the semicircular canals. A 2014 Cochrane review concluded that the Epley manoeuvre is a safe and effective treatment for BPPV, with a number needed to treat of 2-4.

Referral to an ENT specialist is recommended for patients with BPPV in the following situations: if the treating clinician is unable to perform or access the Epley manoeuvre, if the Epley manoeuvre has not been beneficial after repeated attempts (minimum two), if the patient has been symptomatic for more than 4 weeks, or if the patient has experienced more than 3 episodes of BPPV.

In a patient with severe otitis externa on the left side, it is expected that they will experience conductive deafness on the left side. This means that their ability to hear sound will be impaired due to a problem in the ear canal or middle ear. When conducting a Rinne’s test, a vibrating 512 Hz tuning fork is placed on the mastoid process until the patient can no longer hear the sound. Then, the top of the tuning fork is positioned 2 cm from the external auditory meatus, and the patient is asked where they hear the sound loudest.

In individuals with normal hearing, the sound from the tuning fork should still be audible outside the external auditory canal even after it can no longer be heard on the mastoid. This is because air conduction should be better than bone conduction. However, in cases of conductive hearing loss, the patient will no longer be able to hear the tuning fork once it is removed from the mastoid. This indicates that their bone conduction is greater than their air conduction, suggesting an obstruction in the ear canal that prevents sound waves from reaching the cochlea. This is referred to as a true negative result.

It is important to note that a Rinne’s test may yield a false negative result if the patient has a severe unilateral sensorineural deficit. In this case, they may still sense the sound in the unaffected ear due to the transmission of sound through the base of the skull. In contrast, individuals with sensorineural hearing loss will have diminished ability to hear the tuning fork both on the mastoid and outside the external auditory canal compared to the opposite ear. The sound will disappear earlier on the mastoid and outside the external auditory canal in the affected ear.

When performing Weber’s test, a vibrating 512 Hz tuning fork is placed on the center of the patient’s forehead. The patient is then asked if they perceive the sound in the middle of the forehead or if it lateralizes to one side. If the sound lateralizes to one side, it can indicate either ipsilateral conductive hearing loss or contralateral sensorineural hearing loss.

The Arthus reaction is a response that occurs when antigen/antibody complexes are formed in the skin after an antigen is injected. Although rare, these reactions can happen after receiving vaccines that contain tetanus toxoid or diphtheria toxoid. They are classified as a type III hypersensitivity reaction.

Arthus reactions are characterized by pain, swelling, induration, hemorrhage, and sometimes necrosis. Typically, these symptoms appear 4-12 hours after vaccination.

Type III hypersensitivity reactions occur when insoluble antigen-antibody complexes accumulate in different tissues and are not effectively cleared by the body’s innate immune cells. This leads to an inflammatory response in the affected tissues.

Some other examples of type III hypersensitivity reactions include immune complex glomerulonephritis, rheumatoid arthritis, systemic lupus erythematosus, serum sickness, and extrinsic allergic alveolitis.

Acute adrenal insufficiency, also known as Addisonian crisis, is a rare condition that can have catastrophic consequences if not diagnosed in a timely manner. It is more prevalent in women and typically occurs between the ages of 30 and 50.

Addison’s disease is caused by a deficiency in the production of steroid hormones by the adrenal glands, affecting glucocorticoid, mineralocorticoid, and sex steroid production. The main causes of Addison’s disease include autoimmune adrenalitis, bilateral adrenalectomy, Waterhouse-Friderichsen syndrome, tuberculosis, and congenital adrenal hyperplasia.

An Addisonian crisis can be triggered by the intentional or accidental withdrawal of steroid therapy, as well as factors such as 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 in areas such as palmar creases, buccal mucosa, and exposed skin.

During an Addisonian crisis, the main symptoms are usually hypoglycemia and shock, characterized by tachycardia, peripheral vasoconstriction, hypotension, altered consciousness, and even coma.

Biochemical features that can confirm the diagnosis of Addison’s disease include increased ACTH levels, hyponatremia, hyperkalemia, hypercalcemia, hypoglycemia, and metabolic acidosis. Diagnostic investigations may involve the Synacthen test, plasma ACTH level measurement, plasma renin level measurement, and adrenocortical antibody testing.

Management of Addison’s disease should be overseen by an Endocrinologist. Treatment typically involves the administration of hydrocortisone, fludrocortisone, and dehydroepiandrosterone. Some patients may also require thyroxine if there is hypothalamic-pituitary disease present. Treatment is lifelong, and patients should carry a steroid card and MedicAlert bracelet to alert healthcare professionals of their condition and the potential for an Addisonian crisis.

Delirium is an acute syndrome that causes disturbances in consciousness, attention, cognition, and perception. It is also known as an acute confusional state. The DSM-IV criteria for diagnosing delirium include recent onset of fluctuating awareness, impairment of memory and attention, and disorganized thinking. Delirium typically develops over hours to days and may be accompanied by behavioral changes, personality changes, and psychotic features. It often occurs in individuals with predisposing factors, such as advanced age or multiple comorbidities, when exposed to new precipitating factors, such as medications or infection. Symptoms of delirium fluctuate throughout the day, with lucid intervals occurring during the day and worse disturbances at night. Falling and loss of appetite are often warning signs of delirium.

Delirium can be classified into three subtypes based on the person’s symptoms. Hyperactive delirium is characterized by inappropriate behavior, hallucinations, and agitation. Restlessness and wandering are common in this subtype. Hypoactive delirium is characterized by lethargy, reduced concentration, and appetite. The person may appear quiet or withdrawn. Mixed delirium presents with signs and symptoms of both hyperactive and hypoactive subtypes.

The exact pathophysiology of delirium is not fully understood, but it is believed to involve multiple mechanisms, including cholinergic deficiency, dopaminergic excess, and inflammation. The cause of delirium is usually multifactorial, with predisposing factors and precipitating factors playing a role. Predisposing factors include older age, cognitive impairment, frailty, significant injuries, and iatrogenic events. Precipitating factors include infection, metabolic or electrolyte disturbances, cardiovascular disorders, respiratory disorders, neurological disorders, endocrine disorders, urological disorders, gastrointestinal disorders, severe uncontrolled pain, alcohol intoxication or withdrawal, medication use, and psychosocial factors.

Delirium is highly prevalent in hospital settings, affecting up to 50% of patients aged over 65 and occurring in 30% of people aged over 65 presenting to the emergency department. Complications of delirium include increased risk of death, high in-hospital mortality rates, higher mortality rates following hospital discharge, increased length of stay in hospital, nosocomial infections, increased risk of admission to long-term care or re-admission to hospital, increased incidence of dementia, increased risk of falls and associated injuries, pressure sores.

Abducens nerve palsy is often linked to extradural hematoma. When there is a mass effect, downward brain herniation can occur, leading to the involvement of the 6th cranial nerve (abducens nerve, CN VI). This nerve controls the lateral rectus muscle, which is responsible for eye abduction. When the abducens nerve is affected, the lateral rectus muscle is unable to function properly, resulting in an inward turning of the affected eye towards the nose (esotropia).

Further Reading:

Extradural haematoma (EDH) is a collection of blood that forms between the inner surface of the skull and the outer layer of the dura, the dura mater. It is typically caused by head trauma and is often associated with a skull fracture, with the pterion being the most common site of injury. The middle meningeal artery is the most common source of bleeding in EDH.

Clinical features of EDH include a history of head injury with transient loss of consciousness, followed by a lucid interval and gradual loss of consciousness. Other symptoms may include severe headache, sixth cranial nerve palsies, nausea and vomiting, seizures, signs of raised intracranial pressure, and focal neurological deficits.

Imaging of EDH typically shows a biconvex shape and may cause mass effect with brain herniation. It can be differentiated from subdural haematoma by its appearance on imaging.

Management of EDH involves prompt referral to neurosurgery for evacuation of the haematoma. In some cases with a small EDH, conservative management may be considered. With prompt evacuation, the prognosis for EDH is generally good.

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.

In the treatment of diabetic ketoacidosis (DKA), it is important to continue the infusion of insulin until certain criteria are met. These criteria include ketone levels being less than 0.3 mmol/L and the pH of the blood being above 7.3 or the bicarbonate levels being above 18 mmol/L. Additionally, the patient should feel comfortable enough to eat at this point. It is crucial not to stop the intravenous insulin infusion until at least 30 minutes after administering subcutaneous short-acting insulin.

Further Reading:

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

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

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

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

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

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

Écho de la pensée, also known as thought echo, is a psychiatric symptom characterized by the perception of a voice in one’s mind that appears to vocalize thoughts immediately after they are generated.

Thought withdrawal, on the other hand, is a delusional belief where individuals feel that their thoughts have been removed from their own consciousness without their control or consent.

In contrast, thought insertion is a delusional conviction that someone else is influencing or manipulating their thoughts, causing difficulty in distinguishing between their own thoughts and those that have been inserted by another person.

Folie à deux, also referred to as induced psychosis, is a specific type of delusional disorder that is shared by two or more individuals who have a close emotional relationship.

Lastly, echophonia refers to the replication of the voice that can sometimes be heard when listening to the chest during auscultation.

Spontaneous bacterial peritonitis (SBP) is a sudden bacterial infection of the fluid in the abdomen. It typically occurs in patients with high blood pressure in the portal vein, and about 70% of cases are seen in patients with severe liver disease. In any given year, around 30% of patients with fluid buildup in the abdomen will develop SBP.

SBP can present with a wide range of symptoms, so it’s important to be vigilant when caring for patients with fluid buildup in the abdomen, especially if there is a sudden decline in their condition. Some patients may not show any symptoms at all.

Common clinical features of SBP include fever (80% of cases), abdominal pain (70% of cases), worsening or unexplained confusion due to liver dysfunction, diarrhea, nausea and vomiting, and bowel obstruction.

There are several factors that increase the risk of developing SBP, including severe liver disease (Child-Pugh class C), gastrointestinal bleeding, urinary tract infection, excessive growth of bacteria in the intestines, presence of indwelling lines such as central venous catheters or urinary catheters, previous episodes of SBP, and low levels of protein in the fluid buildup in the abdomen.

To diagnose SBP, a procedure called abdominal paracentesis is performed to collect fluid from the abdomen. The following findings on fluid analysis strongly suggest SBP: total white blood cell count in the fluid greater than 500 cells/µL, total neutrophil count in the fluid greater than 250 cells/µL, lactate level in the fluid higher than 25 mg/dL, pH of the fluid below 7.35, and presence of bacteria on Gram-stain.

Patients with SBP should be admitted to the hospital and treated with broad-spectrum antibiotics. The preferred antibiotic is an intravenous third-generation cephalosporin, such as Ceftriaxone. If the patient is allergic to beta-lactam antibiotics, ciprofloxacin can be considered as an alternative. Administration of intravenous albumin has been shown to reduce the risk of kidney failure and death.