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

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

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

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

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

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

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

The 30-point Folstein mini-mental state examination (MMSE) includes a task where the examiner asks the individual to repeat back a phrase. However, this task is not included in the AMTS. The AMTS consists of ten questions that assess different aspects of cognitive function. These questions cover topics such as age, time, year, location, recognition of people, date of birth, historical events, present monarch or prime minister, counting backwards, and recall of an address. The AMTS is a useful tool for evaluating memory loss and is referenced in the RCEM syllabus.

The typical range for the partial pressure of carbon dioxide (pCO2) is 4.4-6.4 kilopascals (kPa). In terms of arterial blood gas (ABG) results, the normal range for pO2 (partial pressure of oxygen) is 10-14.4 kPa or 70-100 millimeters of mercury (mmHg). The normal range for pCO2 is 4.4-6.4 kPa or 35-45 mmHg. Additionally, the normal range for bicarbonate levels is 23-28 millimoles per liter (mmol/L).

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

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

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

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

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

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

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

This patient has presented with an Addisonian crisis, which is a rare but potentially catastrophic condition if not diagnosed promptly. It is more commonly seen in women than men and typically occurs between the ages of 30 and 50.

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

The most common trigger for an Addisonian crisis in patients with Addison’s disease is the intentional or accidental withdrawal of steroid therapy. Other factors that can precipitate a crisis include infection, trauma, myocardial infarction, cerebral infarction, asthma, hypothermia, and alcohol abuse.

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

Biochemical markers of Addison’s disease typically include increased ACTH levels (as a compensatory response to stimulate the adrenal glands), elevated serum renin levels, hyponatremia, hyperkalemia, hypercalcemia, hypoglycemia, and metabolic acidosis. Confirmatory investigations may involve the Synacthen test, plasma ACTH level measurement, plasma renin level measurement, and testing for adrenocortical antibodies.

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

Lidocaine is commonly chosen because it offers some local anesthesia. Alternatively, mineral oil can be used. Cold water irrigation can often cause nausea and vomiting, so it is recommended to use warm water for irrigation. An ENT clinician should be able to remove an insect from the ear canal. However, if removal attempts are unsuccessful or complications arise, a referral may be necessary.

Further Reading:

Foreign bodies in the ear or nose are a common occurrence, especially in children between the ages of 2 and 8. Foreign bodies in the ear are more common than those in the nose. Symptoms of foreign bodies in the ear may include ear pain, a feeling of fullness, impaired hearing, discharge, tinnitus, and vertigo. It is important to consider referral to an ENT specialist for the removal of potentially harmful foreign bodies such as glass, sharp objects, button batteries, and tightly wedged items. ENT involvement is also necessary if there is a perforation of the eardrum or if the foreign body is embedded in the eardrum.

When preparing a patient for removal, it is important to establish rapport and keep the patient relaxed, especially if they are a young child. The patient should be positioned comfortably and securely, and ear drops may be used to anesthetize the ear. Removal methods for foreign bodies in the ear include the use of forceps or a hook, irrigation (except for batteries, perforations, or organic material), suction, and magnets for ferrous metal foreign bodies. If there is an insect in the ear, it should be killed with alcohol, lignocaine, or mineral oil before removal.

After the foreign body is removed, it is important to check for any residual foreign bodies and to discharge the patient with appropriate safety net advice. Prophylactic antibiotic drops may be considered if there has been an abrasion of the skin.

Foreign bodies in the nose are less common but should be dealt with promptly due to the risk of posterior dislodgement into the airway. Symptoms of foreign bodies in the nose may include nasal discharge, sinusitis, nasal pain, epistaxis, or blood-stained discharge. Most nasal foreign bodies are found on the anterior or middle third of the nose and may not show up on x-rays.

Methods for removing foreign bodies from the nose include the mother’s kiss technique, suction, forceps, Jobson horne probe, and foley catheter. The mother’s kiss technique involves occluding the patent nostril and having a parent blow into the patient’s mouth. A foley catheter can be used by inserting it past the foreign body and inflating the balloon to gently push the foreign body out. ENT referral may be necessary if the foreign body cannot be visualized but there is a high suspicion, if attempts to remove the foreign body have failed, if the patient requires sed

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.

Renal colic, also known as ureteric colic, refers to a sudden and intense pain in the loin area caused by a blockage in the ureter, which is the tube that carries urine from the kidney to the bladder. This condition is commonly associated with urinary tract stones. The pain typically starts in the flank or loin and radiates to the labia in women or to the groin or testicle in men.

The pain experienced during renal or ureteric colic is severe and comes in spasms, with periods of no pain or a dull ache in between. It can last for minutes to hours. Nausea, vomiting, and the presence of blood in the urine (haematuria) often accompany the pain. Many individuals describe this pain as the most intense they have ever felt, with some women even comparing it to the pain of childbirth.

People with renal or ureteric colic are restless and unable to find relief by lying still, which helps distinguish this condition from peritonitis. They may have a history of previous episodes and may also present with fever and sweating if there is a concurrent urinary infection. As the stone irritates the detrusor muscle, they may complain of dysuria (painful urination), frequent urination, and straining when the stone reaches the vesicoureteric junction.

To support the diagnosis, it is recommended to perform urine dipstick testing to check for evidence of a urinary tract infection. The presence of blood in the urine can also indicate renal or ureteric colic, although it is not a definitive diagnostic marker. Nitrite and leukocyte esterase in the urine suggest the presence of an infection.

In terms of pain management, non-steroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment for adults, children, and young people with suspected renal colic. Intravenous paracetamol can be offered if NSAIDs are contraindicated or not providing sufficient pain relief. Opioids may be considered if both NSAIDs and intravenous paracetamol are contraindicated or not effective. Antispasmodics should not be given to individuals with suspected renal colic.

For more detailed information, refer to the NICE guidelines on the assessment and management of renal and ureteric stones.

Stevens-Johnson syndrome is a severe and potentially deadly form of erythema multiforme. It can be triggered by anything that causes erythema multiforme, but it is most commonly seen as a reaction to medication within 1-3 weeks of starting treatment. Initially, there may be symptoms like fever, fatigue, joint pain, and digestive issues, followed by the development of severe mucocutaneous lesions that are blistering and ulcerating.

Stevens-Johnson syndrome and toxic epidermal necrolysis are considered to be different stages of the same mucocutaneous disease, with toxic epidermal necrolysis being more severe. The extent of epidermal detachment is used to differentiate between the two. In Stevens-Johnson syndrome, less than 10% of the body surface area is affected by epidermal detachment, while in toxic epidermal necrolysis, it is greater than 30%. An overlap syndrome occurs when detachment affects between 10-30% of the body surface area.

Several drugs can potentially cause Stevens-Johnson syndrome and toxic epidermal necrolysis, including tetracyclines, penicillins, vancomycin, sulphonamides, NSAIDs, and barbiturates.

If the patient is suffering from adrenal insufficiency, it is likely that she will have hyponatremia and hyperkalemia. Adrenal insufficiency occurs when the adrenal glands do not produce enough hormones, particularly cortisol. This can lead to imbalances in electrolytes, such as sodium and potassium. Hyponatremia refers to low levels of sodium in the blood, while hyperkalemia refers to high levels of potassium in the blood. These abnormalities can cause symptoms such as dizziness, weakness, abdominal discomfort, and muscle aches. Additionally, the patient’s reported weight loss and other symptoms are consistent with adrenal insufficiency.

Further Reading:

Addison’s disease, also known as primary adrenal insufficiency or hypoadrenalism, is a rare disorder caused by the destruction of the adrenal cortex. This leads to reduced production of glucocorticoids, mineralocorticoids, and adrenal androgens. The deficiency of cortisol results in increased production of adrenocorticotropic hormone (ACTH) due to reduced negative feedback to the pituitary gland. This condition can cause metabolic disturbances such as hyperkalemia, hyponatremia, hypercalcemia, and hypoglycemia.

The symptoms of Addison’s disease can vary but commonly include fatigue, weight loss, muscle weakness, and low blood pressure. It is more common in women and typically affects individuals between the ages of 30-50. The most common cause of primary hypoadrenalism in developed countries is autoimmune destruction of the adrenal glands. Other causes include tuberculosis, adrenal metastases, meningococcal septicaemia, HIV, and genetic disorders.

The diagnosis of Addison’s disease is often suspected based on low cortisol levels and electrolyte abnormalities. The adrenocorticotropic hormone stimulation test is commonly used for confirmation. Other investigations may include adrenal autoantibodies, imaging scans, and genetic screening.

Addisonian crisis is a potentially life-threatening condition that occurs when there is an acute deficiency of cortisol and aldosterone. It can be the first presentation of undiagnosed Addison’s disease. Precipitating factors of an Addisonian crisis include infection, dehydration, surgery, trauma, physiological stress, pregnancy, hypoglycemia, and acute withdrawal of long-term steroids. Symptoms of an Addisonian crisis include malaise, fatigue, nausea or vomiting, abdominal pain, fever, muscle pains, dehydration, confusion, and loss of consciousness.

There is no fixed consensus on diagnostic criteria for an Addisonian crisis, as symptoms are non-specific. Investigations may include blood tests, blood gas analysis, and septic screens if infection is suspected. Management involves administering hydrocortisone and fluids. Hydrocortisone is given parenterally, and the dosage varies depending on the age of the patient. Fluid resuscitation with saline is necessary to correct any electrolyte disturbances and maintain blood pressure. The underlying cause of the crisis should also be identified and treated. Close monitoring of sodium levels is important to prevent complications such as osmotic demyelination syndrome.

Sodium bicarbonate is used to treat severe TCA toxicity by reducing the risk of seizures and arrhythmia. The goal is to increase the serum pH to a range of 7.45 to 7.55 through alkalinisation.

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.