The intravascular volume of an infant is approximately 80 ml/kg, while in older children it is around 70 ml/kg. Dehydration itself does not lead to death, but shock can occur when there is a loss of 20 ml/kg from the intravascular space. Clinical dehydration becomes evident only after total losses greater than 25 ml/kg.

The table below summarizes the maintenance fluid requirements for well, normal children:

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

Based on this information, the hourly maintenance fluid requirements for this child can be calculated as follows:

– First 10 kg: 4 ml/kg = 40 ml
– Second 10 kg: 2 ml/kg = 20 ml
– Subsequent kg: 1 ml/kg = 5 ml

Therefore, the total hourly maintenance fluid requirement for this child is 65 ml.

When a 35-year-old female comes to the emergency department after a motor vehicle collision, it is important to assess the potential for cervical spine injury. To do this, the Canadian C-spine rules should be utilized. These rules provide a systematic approach to determine whether imaging, such as X-rays, is necessary to evaluate the cervical spine. The Canadian C-spine rules take into account various factors such as the patient’s age, mechanism of injury, and presence of certain symptoms or physical findings. By following these rules, healthcare professionals can effectively evaluate the potential for cervical spine injury and determine the appropriate course of action for further assessment and management.

Further Reading:

When assessing for cervical spine injury, it is recommended to use the Canadian C-spine rules. These rules help determine the risk level for a potential injury. High-risk factors include being over the age of 65, experiencing a dangerous mechanism of injury (such as a fall from a height or a high-speed motor vehicle collision), or having paraesthesia in the upper or lower limbs. Low-risk factors include being involved in a minor rear-end motor vehicle collision, being comfortable in a sitting position, being ambulatory since the injury, having no midline cervical spine tenderness, or experiencing a delayed onset of neck pain. If a person is unable to actively rotate their neck 45 degrees to the left and right, their risk level is considered low. If they have one of the low-risk factors and can actively rotate their neck, their risk level remains low.

If a high-risk factor is identified or if a low-risk factor is identified and the person is unable to actively rotate their neck, full in-line spinal immobilization should be maintained and imaging should be requested. Additionally, if a patient has risk factors for thoracic or lumbar spine injury, imaging should be requested. However, if a patient has low-risk factors for cervical spine injury, is pain-free, and can actively rotate their neck, full in-line spinal immobilization and imaging are not necessary.

NICE recommends CT as the primary imaging modality for cervical spine injury in adults aged 16 and older, while MRI is recommended as the primary imaging modality for children under 16.

Different mechanisms of spinal trauma can cause injury to the spine in predictable ways. The majority of cervical spine injuries are caused by flexion combined with rotation. Hyperflexion can result in compression of the anterior aspects of the vertebral bodies, stretching and tearing of the posterior ligament complex, chance fractures (also known as seatbelt fractures), flexion teardrop fractures, and odontoid peg fractures. Flexion and rotation can lead to disruption of the posterior ligament complex and posterior column, fractures of facet joints, lamina, transverse processes, and vertebral bodies, and avulsion of spinous processes. Hyperextension can cause injury to the anterior column, anterior fractures of the vertebral body, and potential retropulsion of bony fragments or discs into the spinal canal. Rotation can result in injury to the posterior ligament complex and facet joint dislocation.

Hypothermia occurs when the core body temperature drops below 35°C. It is categorized as mild (32-35°C), moderate (28-32°C), or severe (<28°C). Rescuers at the scene can use the Swiss staging system to describe the condition of victims. The stages range from clearly conscious and shivering to unconscious and not breathing, with death due to irreversible hypothermia being the most severe stage. There are several risk factors for hypothermia, including environmental exposure, unsatisfactory housing, poverty, lack of cold awareness, drugs, alcohol, acute confusion, hypothyroidism, and sepsis. The clinical features of hypothermia vary depending on the severity. At 32-35°C, symptoms may include apathy, amnesia, ataxia, and dysarthria. At 30-32°C, there may be a decreased level of consciousness, hypotension, arrhythmias, respiratory depression, and muscular rigidity. Below 30°C, ventricular fibrillation may occur, especially with excessive movement or invasive procedures. Diagnosing hypothermia involves checking the core temperature using an oesophageal, rectal, or tympanic probe with a low reading thermometer. Rectal and tympanic temperatures may lag behind core temperature and are unreliable in hypothermia. Various investigations should be carried out, including blood tests, blood glucose, amylase, blood cultures, arterial blood gas, ECG, chest X-ray, and CT head if there is suspicion of head injury or CVA. The management of hypothermia involves supporting the ABCs, treating the patient in a warm room, removing wet clothes and drying the skin, monitoring the ECG, providing warmed, humidified oxygen, correcting hypoglycemia with IV glucose, and handling the patient gently to avoid VF arrest. Rewarming methods include passive Rewarming with warm blankets or Bair hugger/polythene sheets, surface Rewarming with a water bath, core Rewarming with heated, humidified oxygen or peritoneal lavage, and extracorporeal Rewarming via cardiopulmonary bypass for severe hypothermia/cardiac arrest. In the case of hypothermic cardiac arrest, CPR should be performed with chest compressions and ventilations at standard rates.

Corticosteroids can be beneficial in preventing or reducing prolonged reactions. According to the current APLS guidelines, the recommended doses of hydrocortisone for different age groups are as follows:

– Children under 6 months: 25 mg administered slowly via intramuscular (IM) or intravenous (IV) route.
– Children aged 6 months to 6 years: 50 mg administered slowly via IM or IV route.
– Children aged 6 to 12 years: 100 mg administered slowly via IM or IV route.
– Children over 12 years: 200 mg administered slowly via IM or IV route.
– Adults: 200 mg administered slowly via IM or IV route.

It is important to note that the most recent ALS guidelines do not recommend the routine use of corticosteroids for treating anaphylaxis in adults. However, the current APLS guidelines still advocate for the use of corticosteroids in children to manage anaphylaxis.

Hypercalcaemia, which is an elevated level of calcium in the blood, is most commonly caused by primary hyperparathyroidism and malignancy in the UK. However, there are other factors that can contribute to hypercalcaemia as well. These include an increase in dietary intake of calcium, excessive intake of vitamin D, tertiary hyperparathyroidism, overactive thyroid gland (hyperthyroidism), Addison’s disease, sarcoidosis, Paget’s disease, multiple myeloma, phaeochromocytoma, and milk-alkali syndrome. Additionally, certain medications such as lithium, thiazide diuretics, and theophyllines can also lead to hypercalcaemia. It is important to be aware of these various causes in order to properly diagnose and treat this condition.

The intracranial volume refers to the total space inside the skull. The main component of this volume is the brain parenchyma or neural tissue, which makes up the majority of the intracranial volume.

Further Reading:

Intracranial pressure (ICP) refers to the pressure within the craniospinal compartment, which includes neural tissue, blood, and cerebrospinal fluid (CSF). Normal ICP for a supine adult is 5-15 mmHg. The body maintains ICP within a narrow range through shifts in CSF production and absorption. If ICP rises, it can lead to decreased cerebral perfusion pressure, resulting in cerebral hypoperfusion, ischemia, and potentially brain herniation.

The cranium, which houses the brain, is a closed rigid box in adults and cannot expand. It is made up of 8 bones and contains three main components: brain tissue, cerebral blood, and CSF. Brain tissue accounts for about 80% of the intracranial volume, while CSF and blood each account for about 10%. The Monro-Kellie doctrine states that the sum of intracranial volumes is constant, so an increase in one component must be offset by a decrease in the others.

There are various causes of raised ICP, including hematomas, neoplasms, brain abscesses, edema, CSF circulation disorders, venous sinus obstruction, and accelerated hypertension. Symptoms of raised ICP include headache, vomiting, pupillary changes, reduced cognition and consciousness, neurological signs, abnormal fundoscopy, cranial nerve palsy, hemiparesis, bradycardia, high blood pressure, irregular breathing, focal neurological deficits, seizures, stupor, coma, and death.

Measuring ICP typically requires invasive procedures, such as inserting a sensor through the skull. Management of raised ICP involves a multi-faceted approach, including antipyretics to maintain normothermia, seizure control, positioning the patient with a 30º head up tilt, maintaining normal blood pressure, providing analgesia, using drugs to lower ICP (such as mannitol or saline), and inducing hypocapnoeic vasoconstriction through hyperventilation. If these measures are ineffective, second-line therapies like barbiturate coma, optimised hyperventilation, controlled hypothermia, or decompressive craniectomy may be considered.

For mild cases of otitis externa, using ear drops or spray as the initial treatment is a reasonable option. The insertion of a medicated wick, known as a Pope wick, is typically reserved for patients with severely narrowed external auditory canals. Microsuction, on the other hand, is helpful for patients with excessive debris in their ear canal but is not necessary for this particular patient. In general, microsuction is usually only used for severe cases of otitis externa that require referral to an ear, nose, and throat specialist for further management.

Further Reading:

Otitis externa is inflammation of the skin and subdermis of the external ear canal. It can be acute, lasting less than 6 weeks, or chronic, lasting more than 3 months. Malignant otitis externa, also known as necrotising otitis externa, is a severe and potentially life-threatening infection that can spread to the bones and surrounding structures of the ear. It is most commonly caused by Pseudomonas aeruginosa.

Symptoms of malignant otitis externa include severe and persistent ear pain, headache, discharge from the ear, fever, malaise, vertigo, and profound hearing loss. It can also lead to facial nerve palsy and other cranial nerve palsies. In severe cases, the infection can spread to the central nervous system, causing meningitis, brain abscess, and sepsis.

Acute otitis externa is typically caused by Pseudomonas aeruginosa or Staphylococcus aureus, while chronic otitis externa can be caused by fungal infections such as Aspergillus or Candida albicans. Risk factors for otitis externa include eczema, psoriasis, dermatitis, acute otitis media, trauma to the ear canal, foreign bodies in the ear, water exposure, ear canal obstruction, and long-term antibiotic or steroid use.

Clinical features of otitis externa include itching of the ear canal, ear pain, tenderness of the tragus and/or pinna, ear discharge, hearing loss if the ear canal is completely blocked, redness and swelling of the ear canal, debris in the ear canal, and cellulitis of the pinna and adjacent skin. Tender regional lymphadenitis is uncommon.

Management of acute otitis externa involves general ear care measures, optimizing any underlying medical or skin conditions that are risk factors, avoiding the use of hearing aids or ear plugs if there is a suspected contact allergy, and avoiding the use of ear drops if there is a suspected allergy to any of its ingredients. Treatment options include over-the-counter acetic acid 2% ear drops or spray, aural toileting via dry swabbing, irrigation, or microsuction, and prescribing topical antibiotics with or without a topical corticosteroid. Oral antibiotics may be prescribed in severe cases or for immunocompromised individuals.

Follow-up is advised if symptoms do not improve within 48-72 hours of starting treatment, if symptoms have not fully resolved

Neonatal jaundice is a complex subject, and it is crucial for candidates to have knowledge about the different causes, presentations, and management of conditions that lead to jaundice in newborns. Neonatal jaundice can be divided into two groups: unconjugated hyperbilirubinemia, which can be either physiological or pathological, and conjugated hyperbilirubinemia, which is always pathological.

The causes of neonatal jaundice can be categorized as follows:

Haemolytic unconjugated hyperbilirubinemia:
– Intrinsic causes of haemolysis include hereditary spherocytosis, G6PD deficiency, sickle-cell disease, and pyruvate kinase deficiency.
– Extrinsic causes of haemolysis include haemolytic disease of the newborn and Rhesus disease.

Non-haemolytic unconjugated hyperbilirubinemia:
– Breastmilk jaundice, cephalhaematoma, polycythemia, infection (particularly urinary tract infections), Gilbert syndrome.

Hepatic conjugated hyperbilirubinemia:
– Hepatitis A and B, TORCH infections, galactosaemia, alpha 1-antitrypsin deficiency, drugs.

Post-hepatic conjugated hyperbilirubinemia:
– Biliary atresia, bile duct obstruction, choledochal cysts.

By understanding these different categories and their respective examples, candidates will be better equipped to handle neonatal jaundice cases.

Status epilepticus is a condition characterized by continuous seizure activity lasting for 5 minutes or more without the return of consciousness, or the occurrence of recurrent seizures (2 or more) without any intervening period of neurological recovery.

In the management of a patient with status epilepticus, if the patient has already received two doses of benzodiazepine and is still experiencing seizures, the next step should be to initiate a phenytoin infusion. This involves administering a dose of 15-18 mg/kg at a rate of 50 mg/minute. Alternatively, fosphenytoin can be used as an alternative, and a phenobarbital bolus of 10-15 mg/kg at a rate of 100 mg/minute can also be considered. It is important to note that there is no indication for the administration of intravenous glucose or thiamine in this situation.

The management of status epilepticus involves several general measures. In the early stage (0-10 minutes), the airway should be secured and resuscitation should be performed. Oxygen should be administered and the patient’s cardiorespiratory function should be assessed. Intravenous access should also be established.

In the second stage (0-30 minutes), regular monitoring should be instituted. It is important to consider the possibility of non-epileptic status and commence emergency antiepileptic drug (AED) therapy. Emergency investigations should be conducted, including the administration of glucose (50 ml of 50% solution) and/or intravenous thiamine if there is any suggestion of alcohol abuse or impaired nutrition. Acidosis should be treated if it is severe.

In the third stage (0-60 minutes), the underlying cause of the status epilepticus should be identified. The anaesthetist and intensive care unit (ITU) should be alerted, and any medical complications should be identified and treated. Pressor therapy may be appropriate in certain cases.

In the fourth stage (30-90 minutes), the patient should be transferred to the intensive care unit. Intensive care and EEG monitoring should be established, and intracranial pressure monitoring may be necessary in certain cases. Initial long-term, maintenance AED therapy should also be initiated.

Emergency investigations should include blood tests for blood gases, glucose, renal and liver function, calcium and magnesium, full blood count (including platelets), blood clotting, and AED drug levels.

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

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

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

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

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

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.

The NICE recommendations for managing patients with suspected TIA are as follows:

– Offer aspirin (300 mg daily) to individuals who have experienced a suspected TIA, unless there are contraindications. This treatment should be started immediately.
– Immediately refer individuals who have had a suspected TIA for specialist assessment and investigation. They should be seen within 24 hours of the onset of symptoms.
– Avoid using scoring systems, such as ABCD2, to assess the risk of subsequent stroke or determine the urgency of referral for individuals with suspected or confirmed TIA.
– Provide secondary prevention measures, in addition to aspirin, as soon as possible after confirming the diagnosis of TIA.

The NICE recommendations for imaging in individuals with suspected TIA or acute non-disabling stroke are as follows:

– Do not offer CT brain scanning to individuals with suspected TIA, unless there is clinical suspicion of an alternative diagnosis that CT could detect.
– After a specialist assessment in the TIA clinic, consider performing an MRI (including diffusion-weighted and blood-sensitive sequences) to determine the area of ischemia, detect hemorrhage, or identify alternative pathologies. If an MRI is conducted, it should be done on the same day as the assessment.
– Carotid imaging is necessary for all individuals with TIA who, after specialist assessment, are considered candidates for carotid endarterectomy. This imaging should be done urgently.

For more information, refer to the NICE guidelines on stroke and transient ischaemic attack in individuals over 16 years old: diagnosis and initial management.

Atropine and pralidoxime are both considered antidotes for treating organophosphate poisoning. Organophosphates work by inhibiting acetylcholinesterase at nerve synapses. In addition to providing supportive care and administering antidotes, it is important to decontaminate patients as part of their treatment plan for organophosphate poisoning.

While both atropine and pralidoxime are recognized as antidotes, pralidoxime is not commonly used. Atropine works by competing with acetylcholine at the muscarinic receptors. On the other hand, pralidoxime helps reactivate acetylcholinesterase-organophosphate complexes that have not lost an alkyl side chain, known as non-aged complexes. However, pralidoxime is not effective against organophosphates that have already formed or rapidly form aged acetylcholinesterase complexes. The evidence regarding the effectiveness of pralidoxime is conflicting.

Further Reading:

Chemical incidents can occur as a result of leaks, spills, explosions, fires, terrorism, or the use of chemicals during wars. Industrial sites that use chemicals are required to conduct risk assessments and have accident plans in place for such incidents. Health services are responsible for decontamination, unless mass casualties are involved, and all acute health trusts must have major incident plans in place.

When responding to a chemical incident, hospitals prioritize containment of the incident and prevention of secondary contamination, triage with basic first aid, decontamination if not done at the scene, recognition and management of toxidromes (symptoms caused by exposure to specific toxins), appropriate supportive or antidotal treatment, transfer to definitive treatment, a safe end to the hospital response, and continuation of business after the event.

To obtain advice when dealing with chemical incidents, the two main bodies are Toxbase and the National Poisons Information Service. Signage on containers carrying chemicals and material safety data sheets (MSDS) accompanying chemicals also provide information on the chemical contents and their hazards.

Contamination in chemical incidents can occur in three phases: primary contamination from the initial incident, secondary contamination spread via contaminated people leaving the initial scene, and tertiary contamination spread to the environment, including becoming airborne and waterborne. The ideal personal protective equipment (PPE) for chemical incidents is an all-in-one chemical-resistant overall with integral head/visor and hands/feet worn with a mask, gloves, and boots.

Decontamination of contaminated individuals involves the removal and disposal of contaminated clothing, followed by either dry or wet decontamination. Dry decontamination is suitable for patients contaminated with non-caustic chemicals and involves blotting and rubbing exposed skin gently with dry absorbent material. Wet decontamination is suitable for patients contaminated with caustic chemicals and involves a warm water shower while cleaning the body with simple detergent.

After decontamination, the focus shifts to assessing the extent of any possible poisoning and managing it. The patient’s history should establish the chemical the patient was exposed to, the volume and concentration of the chemical, the route of exposure, any protective measures in place, and any treatment given. Most chemical poisonings require supportive care using standard resuscitation principles, while some chemicals have specific antidotes. Identifying toxidromes can be useful in guiding treatment, and specific antidotes may be administered accordingly.

Acute epiglottitis is inflammation of the epiglottis, which can be life-threatening if not treated promptly. When the soft tissues surrounding the epiglottis are also affected, it is called acute supraglottitis. This condition is most commonly seen in children between the ages of 3 and 5, but it can occur at any age, with adults typically presenting in their 40s and 50s.

In the past, Haemophilus influenzae type B was the main cause of acute epiglottitis, but with the introduction of the Hib vaccination, it has become rare in children. Streptococcus spp. is now the most common causative organism. Other potential culprits include Staphylococcus aureus, Pseudomonas spp., Moraxella catarrhalis, Mycobacterium tuberculosis, and the herpes simplex virus. In immunocompromised patients, Candida spp. and Aspergillus spp. infections can occur.

The typical symptoms of acute epiglottitis include fever, sore throat, painful swallowing, difficulty swallowing secretions (especially in children who may drool), muffled voice, stridor, respiratory distress, rapid heartbeat, tenderness in the front of the neck over the hyoid bone, ear pain, and swollen lymph nodes in the neck. Some patients may also exhibit the tripod sign, where they lean forward on outstretched arms to relieve upper airway obstruction.

To diagnose acute epiglottitis, fibre-optic laryngoscopy is considered the gold standard investigation. However, this procedure should only be performed by an anaesthetist in a setting prepared for intubation or tracheostomy in case of airway obstruction. Other useful tests include a lateral neck X-ray to look for the thumbprint sign, throat swabs, blood cultures, and a CT scan of the neck if an abscess is suspected.

When dealing with a case of acute epiglottitis, it is crucial not to panic or distress the patient, especially in pediatric cases. Avoid attempting to examine the throat with a tongue depressor, as this can trigger spasm and worsen airway obstruction. Instead, keep the patient as calm as possible and immediately call a senior anaesthetist, a senior paediatrician, and an ENT surgeon. Nebulized adrenaline can be used as a temporary measure if there is critical airway obstruction.

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 patients are classified as Child-Pugh class C. In any given year, around 30% of patients with ascites, a condition characterized by 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 ascites, 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, chills, nausea, vomiting, abdominal pain, tenderness, worsening ascites, general malaise, and hepatic encephalopathy. Certain factors can increase the risk of developing SBP, such as severe liver disease, gastrointestinal bleeding, urinary tract infection, intestinal bacterial overgrowth, indwelling lines (e.g., central venous catheters or urinary catheters), previous episodes of SBP, and low levels of protein in the ascitic fluid.

To diagnose SBP, an abdominal paracentesis, also known as an ascitic tap, is performed. This involves locating the area of dullness on the flank, next to the rectus abdominis muscle, and performing the tap about 5 cm above and towards the midline from the anterior superior iliac spines.

Certain features on the analysis of the peritoneal fluid strongly suggest SBP, including a total white cell count in the ascitic fluid of more than 500 cells/µL, a total neutrophil count of more than 250 cells/µL, a lactate level in the ascitic fluid of more than 25 mg/dL, a pH of less than 7.35, and the presence of bacteria on Gram-stain.

Patients diagnosed with SBP should be admitted to the hospital and given broad-spectrum antibiotics. The preferred choice is an intravenous 3rd generation cephalosporin, such as ceftriaxone. If the patient is allergic to beta-lactam antibiotics, ciprofloxacin can be considered as an alternative. Administering intravenous albumin can help reduce the risk of kidney failure and mortality.

Enzyme-inducing anticonvulsants have been found to enhance the metabolism of ethinyl estradiol and progestogens. This increased breakdown diminishes the effectiveness of the oral contraceptive pill (OCP) in preventing pregnancy. Some examples of enzyme-inducing anticonvulsants include carbamazepine, phenytoin, phenobarbitol, and topiramate.

On the other hand, non-enzyme-inducing anticonvulsants are unlikely to have an impact on contraception. Some examples of these anticonvulsants are sodium valproate, clonazepam, gabapentin, levetiracetam, and piracetam.

It is important to note that lamotrigine, although classified as a non-enzyme-inducing anticonvulsant, requires special consideration. While there is no evidence suggesting that the OCP directly affects epilepsy, there is evidence indicating that it reduces the levels of lamotrigine in the bloodstream. This reduction in lamotrigine levels could potentially compromise seizure control and increase the likelihood of experiencing seizures.

Spontaneous bacterial peritonitis (SBP) is a condition that occurs as a complication of ascites, which is the accumulation of fluid in the abdomen. SBP typically presents with various symptoms such as fevers, chills, nausea, vomiting, abdominal pain, general malaise, altered mental status, and worsening ascites. This patient is at risk of developing alcoholic liver disease and cirrhosis due to their harmful levels of alcohol consumption. Harmful drinking is defined as drinking ≥ 35 units a week for women or drinking ≥ 50 units a week for men. The presence of shifting dullness and a distended abdomen are consistent with the presence of ascites. SBP is an acute bacterial infection of the ascitic fluid that occurs without an obvious identifiable cause. It is one of the most commonly encountered bacterial infections in patients with cirrhosis. Signs and symptoms of SBP include fevers, chills, nausea, vomiting, abdominal pain and tenderness, general malaise, altered mental status, and worsening ascites.

Further Reading:

Cirrhosis is a condition where the liver undergoes structural changes, resulting in dysfunction of its normal functions. It can be classified as either compensated or decompensated. Compensated cirrhosis refers to a stage where the liver can still function effectively with minimal symptoms, while decompensated cirrhosis is when the liver damage is severe and clinical complications are present.

Cirrhosis develops over a period of several years due to repeated insults to the liver. Risk factors for cirrhosis include alcohol misuse, hepatitis B and C infection, obesity, type 2 diabetes, autoimmune liver disease, genetic conditions, certain medications, and other rare conditions.

The prognosis of cirrhosis can be assessed using the Child-Pugh score, which predicts mortality based on parameters such as bilirubin levels, albumin levels, INR, ascites, and encephalopathy. The score ranges from A to C, with higher scores indicating a poorer prognosis.

Complications of cirrhosis include portal hypertension, ascites, hepatic encephalopathy, variceal hemorrhage, increased infection risk, hepatocellular carcinoma, and cardiovascular complications.

Diagnosis of cirrhosis is typically done through liver function tests, blood tests, viral hepatitis screening, and imaging techniques such as transient elastography or acoustic radiation force impulse imaging. Liver biopsy may also be performed in some cases.

Management of cirrhosis involves treating the underlying cause, controlling risk factors, and monitoring for complications. Complications such as ascites, spontaneous bacterial peritonitis, oesophageal varices, and hepatic encephalopathy require specific management strategies.

Overall, cirrhosis is a progressive condition that requires ongoing monitoring and management to prevent further complications and improve outcomes for patients.

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

Type I hypersensitivity reactions are allergic reactions that occur when a person is exposed again to a particular antigen, known as an allergen. These reactions are triggered by IgE and typically happen within 15 to 30 minutes after exposure to the allergen.

A rapid onset of an urticarial rash, which occurs shortly after being exposed to an allergen (such as latex), is highly likely to be caused by a type I hypersensitivity reaction.

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 intravenous drug users and those with weakened immune systems. Gram-negative organisms such as Escherichia coli and Mycobacterium tuberculosis can also cause discitis.

There are several risk factors that increase the likelihood of developing discitis. These include having undergone spinal surgery (which occurs in 1-2% of cases 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, refusal to walk may also be a symptom.

When diagnosing discitis, 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. CT scanning is also not very sensitive in detecting discitis.

Treatment for discitis involves admission to the hospital for intravenous antibiotics. Before starting the antibiotics, it is important to send three sets of blood cultures and a full set of blood tests, including a CRP, to the lab. The choice of antibiotics depends on the specific situation. A typical antibiotic regimen for discitis may include IV flucloxacillin as the first-line treatment if there is no penicillin allergy, IV vancomycin if the infection was acquired in the hospital or there is a high risk of MRSA, and possibly IV gentamicin if there is a possibility of a Gram-negative infection. In cases where there is acute kidney injury and Gram-negative cover is required, IV piperacillin-tazobactam alone may be used.

Nephrogenic diabetes insipidus may develop in a certain percentage of individuals who take lithium.

Further Reading:

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

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

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

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

Patients who have taken an overdose of tricyclic antidepressants (TCAs) should not be given phenytoin.

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.

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.

Flucloxacillin is recommended as the initial treatment for mild cellulitis, according to NICE guidelines. The recommended dosage for flucloxacillin is 500-1000 mg taken four times a day for a period of 5-7 days. However, if a patient is allergic to penicillin or if flucloxacillin is not suitable for them, alternative medications such as clarithromycin, doxycycline, or erythromycin can be used as second-line options. It is important to note that for cellulitis near the eyes, co-amoxiclav is advised as the first-line treatment, while for cellulitis in patients with lymphedema who do not require hospital admission, amoxicillin is recommended as the first-line treatment.

Further Reading:

Cellulitis is an inflammation of the skin and subcutaneous tissues caused by an infection, usually by Streptococcus pyogenes or Staphylococcus aureus. It commonly occurs on the shins and is characterized by symptoms such as erythema, pain, swelling, and heat. In some cases, there may also be systemic symptoms like fever and malaise.

The NICE Clinical Knowledge Summaries recommend using the Eron classification to determine the appropriate management of cellulitis. Class I cellulitis refers to cases without signs of systemic toxicity or uncontrolled comorbidities. Class II cellulitis involves either systemic illness or the presence of a co-morbidity that may complicate or delay the resolution of the infection. Class III cellulitis is characterized by significant systemic upset or limb-threatening infection due to vascular compromise. Class IV cellulitis involves sepsis syndrome or a severe life-threatening infection like necrotizing fasciitis.

According to the guidelines, patients with Eron Class III or Class IV cellulitis should be admitted for intravenous antibiotics. This also applies to patients with severe or rapidly deteriorating cellulitis, very young or frail individuals, immunocompromised patients, those with significant lymphedema, and those with facial or periorbital cellulitis (unless very mild). Patients with Eron Class II cellulitis may not require admission if the necessary facilities and expertise are available in the community to administer intravenous antibiotics and monitor the patient.

The recommended first-line treatment for mild to moderate cellulitis is flucloxacillin. For patients allergic to penicillin, clarithromycin or clindamycin is recommended. In cases where patients have failed to respond to flucloxacillin, local protocols may suggest the use of oral clindamycin. Severe cellulitis should be treated with intravenous benzylpenicillin and flucloxacillin.

Overall, the management of cellulitis depends on the severity of the infection and the presence of any systemic symptoms or complications. Prompt treatment with appropriate antibiotics is crucial to prevent further complications and promote healing.

Cardiopulmonary bypass (CPB) is the most efficient technique for warming up a patient who is experiencing hypothermia. While other methods may also be suitable and may have already been initiated by the paramedic team, CPB stands out as the most effective approach.

Further Reading:

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

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

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

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

When caring for a patient with a declining Glasgow Coma Scale (GCS) who may require rapid sequence induction (RSI), it is important to consider their medical history. In this case, the patient has a history of asthma. One of the induction medications that is recognized for its bronchodilatory effects and would be appropriate for use in an asthmatic patient is Ketamine.

Further Reading:

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

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

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

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

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

NICE provides a list of reasons for admitting patients with acute alcohol withdrawal. These include individuals who are deemed to be at risk of experiencing withdrawal seizures or delirium tremens. Additionally, young people under the age of 16 who are going through acute alcohol withdrawal may also require admission. Furthermore, vulnerable individuals, such as those who are frail, have cognitive impairment or multiple comorbidities, lack social support, or have learning difficulties, may also benefit from being admitted for acute alcohol withdrawal. For more information, please refer to the NICE pathway for acute alcohol withdrawal.

The most likely cause of the fainting episode in this 25-year-old third year medical student is vasovagal syncope. Vasovagal syncope is a common type of fainting that occurs in response to certain triggers, such as emotional stress, pain, or seeing blood. In this case, the prolonged delivery and emergency C-section likely triggered the patient’s vasovagal response.

The patient’s symptoms of feeling warm and sweaty before fainting are consistent with vasovagal syncope. During a vasovagal episode, there is a sudden drop in blood pressure and heart rate, leading to a temporary loss of consciousness. The absence of loss of bladder or bowel control and tongue biting further support this diagnosis.

The physical examination findings of no focal neurological deficits and a normal cardiovascular examination also align with vasovagal syncope. Additionally, the blood pressure measurements of 122/74 mmHg when lying down and 120/72 mmHg when standing suggest orthostatic hypotension, which is commonly seen in vasovagal syncope.

Further Reading:

Blackouts, also known as syncope, are defined as a spontaneous transient loss of consciousness with complete recovery. They are most commonly caused by transient inadequate cerebral blood flow, although epileptic seizures can also result in blackouts. There are several different causes of blackouts, including neurally-mediated reflex syncope (such as vasovagal syncope or fainting), orthostatic hypotension (a drop in blood pressure upon standing), cardiovascular abnormalities, and epilepsy.

When evaluating a patient with blackouts, several key investigations should be performed. These include an electrocardiogram (ECG), heart auscultation, neurological examination, vital signs assessment, lying and standing blood pressure measurements, and blood tests such as a full blood count and glucose level. Additional investigations may be necessary depending on the suspected cause, such as ultrasound or CT scans for aortic dissection or other abdominal and thoracic pathology, chest X-ray for heart failure or pneumothorax, and CT pulmonary angiography for pulmonary embolism.

During the assessment, it is important to screen for red flags and signs of any underlying serious life-threatening condition. Red flags for blackouts include ECG abnormalities, clinical signs of heart failure, a heart murmur, blackouts occurring during exertion, a family history of sudden cardiac death at a young age, an inherited cardiac condition, new or unexplained breathlessness, and blackouts in individuals over the age of 65 without a prodrome. These red flags indicate the need for urgent assessment by an appropriate specialist.

There are several serious conditions that may be suggested by certain features. For example, myocardial infarction or ischemia may be indicated by a history of coronary artery disease, preceding chest pain, and ECG signs such as ST elevation or arrhythmia. Pulmonary embolism may be suggested by dizziness, acute shortness of breath, pleuritic chest pain, and risk factors for venous thromboembolism. Aortic dissection may be indicated by chest and back pain, abnormal ECG findings, and signs of cardiac tamponade include low systolic blood pressure, elevated jugular venous pressure, and muffled heart sounds. Other conditions that may cause blackouts include severe hypoglycemia, Addisonian crisis, and electrolyte abnormalities.

The current recommendations from NICE for managing warfarin in the presence of bleeding or an abnormal INR are as follows:

In cases of major active bleeding, regardless of the INR level, the first step is to stop administering warfarin. Next, 5 mg of vitamin K (phytomenadione) should be given intravenously. Additionally, dried prothrombin complex concentrate, which contains factors II, VII, IX, and X, should be administered. If dried prothrombin complex is not available, fresh frozen plasma can be given at a dose of 15 ml/kg.

If the INR is greater than 8.0 and there is minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is greater than 8.0 with no bleeding, warfarin should be stopped. Oral administration of 1-5 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with no bleeding, one or two doses of warfarin should be withheld, and the subsequent maintenance dose should be reduced.

For more information, please refer to the NICE Clinical Knowledge Summary on the management of warfarin therapy and the BNF guidance on the use of phytomenadione.

Hyperkalaemia is when the level of potassium in the blood is higher than 5.5 mmol/l. It can be categorized as mild, moderate, or severe depending on the specific potassium levels. Mild hyperkalaemia is between 5.5-5.9 mmol/l, moderate hyperkalaemia is between 6.0-6.4 mmol/l, and severe hyperkalaemia is above 6.5 mmol/l. The most common cause of hyperkalaemia in renal failure, which can be acute or chronic. Other causes include acidosis, adrenal insufficiency, cell lysis, and excessive potassium intake.

Calcium is used to counteract the harmful effects of hyperkalaemia on the heart by stabilizing the cardiac cell membrane and preventing abnormal depolarization. It works quickly, usually within 15 minutes, but its effects are not long-lasting. Calcium is considered a first-line treatment for arrhythmias and significant ECG abnormalities caused by hyperkalaemia, such as widening of the QRS interval, loss of the P wave, and cardiac arrhythmias. However, arrhythmias are rare at potassium levels below 7.5 mmol/l.

It’s important to note that calcium does not lower the serum potassium level. Therefore, it should be used in conjunction with other therapies that actually help reduce potassium levels, such as insulin and salbutamol. If the pH is measured to be above 7.35 and the potassium level remains high despite nebulized salbutamol, the APLS guidelines recommend the administration of an insulin and glucose infusion.