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.

The current guidelines from NICE and the BNF suggest that if treatment is necessary for campylobacter enteritis, clarithromycin should be the first choice. Azithromycin and erythromycin can be used interchangeably, and ciprofloxacin is a suitable alternative. It is important to note that many cases of campylobacter enteritis resolve on their own without treatment. However, individuals with severe infections or those who are immunocompromised should receive treatment.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Epiglottitis symptoms typically appear suddenly, usually within a day. This patient’s symptoms align with those of epiglottitis and his vaccination status puts him at a higher risk. Common clinical features of epiglottitis include a rapid onset of symptoms, high fever, a sore throat, a change in voice (often described as a muffled or hot potato voice), painful swallowing, a specific positioning called tripod positioning, excessive drooling, and stridor.

Further Reading:

Epiglottitis is a rare but serious condition characterized by inflammation and swelling of the epiglottis, which can lead to a complete blockage of the airway. It is more commonly seen in children between the ages of 2-6, but can also occur in adults, particularly those in their 40s and 50s. Streptococcus infections are now the most common cause of epiglottitis in the UK, although other bacterial agents, viruses, fungi, and iatrogenic causes can also be responsible.

The clinical features of epiglottitis include a rapid onset of symptoms, high fever, sore throat, painful swallowing, muffled voice, stridor and difficulty breathing, drooling of saliva, irritability, and a characteristic tripod positioning with the arms forming the front two legs of the tripod. It is important for healthcare professionals to avoid examining the throat or performing any potentially upsetting procedures until the airway has been assessed and secured.

Diagnosis of epiglottitis is typically made through fibre-optic laryngoscopy, which is considered the gold standard investigation. Lateral neck X-rays may also show a characteristic thumb sign, indicating an enlarged and swollen epiglottis. Throat swabs and blood cultures may be taken once the airway is secured to identify the causative organism.

Management of epiglottitis involves assessing and securing the airway as the top priority. Intravenous or oral antibiotics are typically prescribed, and supplemental oxygen may be given if intubation or tracheostomy is planned. In severe cases where the airway is significantly compromised, intubation or tracheostomy may be necessary. Steroids may also be used, although the evidence for their benefit is limited.

Overall, epiglottitis is a potentially life-threatening condition that requires urgent medical attention. Prompt diagnosis, appropriate management, and securing the airway are crucial in ensuring a positive outcome for patients with this condition.

Infectious factors that can lead to back pain consist of discitis, vertebral osteomyelitis, and spinal epidural abscess. There are certain warning signs, known as red flags, that indicate the presence of an infectious cause for back pain. These red flags include experiencing a fever, having tuberculosis, being diabetic, having recently had a bacterial infection such as a urinary tract infection, engaging in intravenous drug use, and having a weakened immune system due to conditions like HIV or the use of immunosuppressant drugs.

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

Further Reading:

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

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

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

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

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

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

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

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

Bullous pemphigoid (BP) is a chronic autoimmune disorder that affects the skin, causing blistering. It occurs when the immune system mistakenly attacks the basement membrane of the epidermis. This attack is carried out by immunoglobulins (IgG and sometimes IgE) and activated T lymphocytes. The autoantibodies bind to proteins and release cytokines, leading to complement activation, neutrophil recruitment, and the release of enzymes that destroy the hemidesmosomes. As a result, subepidermal blisters form.

Pemphigus, on the other hand, is a group of autoimmune disorders characterized by blistering of the skin and mucosal surfaces. The most common type, pemphigus vulgaris (PV), accounts for about 70% of cases worldwide. PV is also autoimmune in nature, with autoantibodies targeting cell surface antigens on keratinocytes (desmogleins 1 and 3). This leads to a loss of adhesion between cells and their separation.

Here is a comparison of the key differences between pemphigus vulgaris and bullous pemphigoid:

Pemphigus vulgaris:
– Age: Middle-aged people (average age 50)
– Oral involvement: Common
– Blister type: Large, flaccid, and painful
– Blister content: Fluid-filled, often haemorrhagic
– Areas commonly affected: Initially face and scalp, then spread to the chest and back
– Nikolsky sign: Usually positive
– Pruritus: Rare
– Skin biopsy: Intra-epidermal deposition of IgG between cells throughout the epidermis

Bullous pemphigoid:
– Age: Elderly people (average age 80)
– Oral involvement: Rare
– Blister type: Large and tense
– Blister content: Fluid-filled
– Areas commonly affected: Upper arms, thighs, and skin flexures
– Nikolsky sign: Usually negative
– Pruritus: Common
– Skin biopsy: A band of IgG and/or C3 at the dermo-epidermal junction

Occlusion of the posterior inferior cerebellar artery leads to the development of lateral medullary syndrome, also known as Wallenberg’s syndrome. This condition is characterized by several distinct symptoms. Firstly, there is a loss of pain and temperature sensation on the opposite side of the body, which occurs due to damage to the spinothalamic tracts. Additionally, there is a loss of pain and temperature sensation on the same side of the face, resulting from damage to the fifth cranial nerve (CN V).

Furthermore, individuals with lateral medullary syndrome may experience vertigo, nystagmus, tinnitus, deafness, and vomiting. These symptoms arise from damage to the eighth cranial nerve (CN VIII). Lastly, the syndrome may also present with Horner’s syndrome, which is caused by damage to the descending hypothalamospinal tract.

In summary, occlusion of the posterior inferior cerebellar artery causes lateral medullary syndrome, leading to a combination of symptoms including sensory loss, vertigo, tinnitus, and Horner’s syndrome.

In pediatric patients who have sustained burns in a house fire, the presence of burns greater than 15% of the total body surface area should trigger the initiation of immediate fluid resuscitation.

Further Reading:

Burn injuries can be classified based on their type (degree, partial thickness or full thickness), extent as a percentage of total body surface area (TBSA), and severity (minor, moderate, major/severe). Severe burns are defined as a >10% TBSA in a child and >15% TBSA in an adult.

When assessing a burn, it is important to consider airway injury, carbon monoxide poisoning, type of burn, extent of burn, special considerations, and fluid status. Special considerations may include head and neck burns, circumferential burns, thorax burns, electrical burns, hand burns, and burns to the genitalia.

Airway management is a priority in burn injuries. Inhalation of hot particles can cause damage to the respiratory epithelium and lead to airway compromise. Signs of inhalation injury include visible burns or erythema to the face, soot around the nostrils and mouth, burnt/singed nasal hairs, hoarse voice, wheeze or stridor, swollen tissues in the mouth or nostrils, and tachypnea and tachycardia. Supplemental oxygen should be provided, and endotracheal intubation may be necessary if there is airway obstruction or impending obstruction.

The initial management of a patient with burn injuries involves conserving body heat, covering burns with clean or sterile coverings, establishing IV access, providing pain relief, initiating fluid resuscitation, measuring urinary output with a catheter, maintaining nil by mouth status, closely monitoring vital signs and urine output, monitoring the airway, preparing for surgery if necessary, and administering medications.

Burns can be classified based on the depth of injury, ranging from simple erythema to full thickness burns that penetrate into subcutaneous tissue. The extent of a burn can be estimated using methods such as the rule of nines or the Lund and Browder chart, which takes into account age-specific body proportions.

Fluid management is crucial in burn injuries due to significant fluid losses. Evaporative fluid loss from burnt skin and increased permeability of blood vessels can lead to reduced intravascular volume and tissue perfusion. Fluid resuscitation should be aggressive in severe burns, while burns <15% in adults and <10% in children may not require immediate fluid resuscitation. The Parkland formula can be used to calculate the intravenous fluid requirements for someone with a significant burn injury.

This patient is experiencing a condition called right-sided abducens nerve palsy, which means that their sixth cranial nerve is paralyzed. As a result, the lateral rectus muscle, which is responsible for moving the eye outward, is also paralyzed. This means that the patient’s right eye is unable to turn outward. This can lead to a condition called convergent strabismus, where the eyes are not aligned properly, and diplopia, which is double vision. To compensate for the double vision, patients often tilt their head towards the side of the paralyzed muscle.