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  • Question 1 - A 7-year-old boy is diagnosed with metabolic acidosis as a result of severe...

    Incorrect

    • A 7-year-old boy is diagnosed with metabolic acidosis as a result of severe dehydration. Which of the following conditions is most likely to cause severe dehydration and metabolic acidosis?

      Your Answer: Severe persistent vomiting

      Correct Answer: Severe diarrhoea

      Explanation:

      Diarrhoea is defined as having three or more loose or liquid stools per day, or as having more stools than is normal for that person. Severe diarrhoea, causing fluid loss and loss of bicarbonate, will result in marked dehydration and metabolic acidosis.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      24.6
      Seconds
  • Question 2 - A 25-year-old female had a painful abdomen and several episodes of vomiting. She...

    Correct

    • A 25-year-old female had a painful abdomen and several episodes of vomiting. She was severely dehydrated when she was brought to the hospital. Her ABG showed a pH 7.7, p(O2) 75 mmHg, p(CO2) 46 mmHg and bicarbonate 48 mmol/l. The most likely interpretation of this ABG report would be:

      Your Answer: Metabolic alkalosis

      Explanation:

      Metabolic alkalosis is a primary increase in bicarbonate (HCO3−) with or without compensatory increase in carbon dioxide partial pressure (Pco2); pH may be high or nearly normal. Metabolic alkalosis occurs as a consequence of a loss of H+ from the body or a gain in HCO3 -. In its pure form, it manifests as alkalemia (pH >7.40). As a compensatory mechanism, metabolic alkalosis leads to alveolar hypoventilation with a rise in arterial carbon dioxide tension p(CO2), which diminishes the change in pH that would otherwise occur. Normally, arterial p(CO2) increases by 0.5–0.7 mmHg for every 1 mmol/l increase in plasma bicarbonate concentration, a compensatory response that occurs very rapidly. If the change in p(CO2) is not within this range, then a mixed acid–base disturbance occurs. Likewise, if the increase in p(CO2) is less than the expected change, then a primary respiratory alkalosis is also present. However an elevated serum bicarbonate concentration can also occur due to a compensatory response to primary respiratory acidosis. A bicarbonate concentration greater than 35 mmol/l is almost always caused by metabolic alkalosis (as is the case in this clinical scenario). Calculation of the serum anion gap can also help to differentiate between primary metabolic alkalosis and the metabolic compensation for respiratory acidosis. The anion gap is frequently elevated to a modest degree in metabolic alkalosis because of the increase in the negative charge of albumin and the enhanced production of lactate. However, the only definitive way to diagnose metabolic alkalosis is by performing a simultaneous blood gases analysis, which reveals elevation of both pH and arterial p(CO2) and increased calculated bicarbonate.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      25.1
      Seconds
  • Question 3 - Which of the following conditions causes an elevation of the pH in the...

    Incorrect

    • Which of the following conditions causes an elevation of the pH in the tissues with elevated arterial CO2 content?

      Your Answer: Respiratory alkalosis

      Correct Answer: Metabolic alkalosis

      Explanation:

      Metabolic alkalosis is a metabolic condition in which the pH of tissue is elevated beyond the normal range (7.35-7.45). This is the result of decreased hydrogen ion concentration, leading to increased bicarbonate, or alternatively a direct result of increased bicarbonate concentrations. Normally, arterial pa(CO2) increases by 0.5–0.7 mmHg for every 1 mEq/l increase in plasma bicarbonate concentration, a compensatory response that is very quick. If the change in pa(CO2) is not within this range, then a mixed acid–base disturbance occurs.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      27.3
      Seconds
  • Question 4 - A 20-year-old woman had profuse watery diarrhoea for 2 days. She felt dizzy...

    Incorrect

    • A 20-year-old woman had profuse watery diarrhoea for 2 days. She felt dizzy and weak, and thus decided to seek medical attention. At the emergency room her BP was 80/60 mmHg with a pulse of 118/min. What is the most appropriate intravenous treatment that should be given?

      Your Answer: 5% dextrose in water

      Correct Answer: Isotonic saline

      Explanation:

      Normal saline is typically the first fluid used when hypovolemia is severe enough to threaten the adequacy of blood circulation. It is isotonic and has long been believed to be the safest fluid to give quickly in large volumes.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      23.3
      Seconds
  • Question 5 - Some substances, such as Chromium-51 and Technetium-99, are freely filtered but not secreted...

    Correct

    • Some substances, such as Chromium-51 and Technetium-99, are freely filtered but not secreted or absorbed by the kidney. In these cases, their clearance rate is equal to:

      Your Answer: Glomerular filtration rate

      Explanation:

      If a substance passes through the glomerular membrane with perfect ease, the glomerular filtrate contains virtually the same concentration of the substance as does the plasma and if the substance is neither secreted nor reabsorbed by the tubules, all of the filtered substance continues on into the urine. Glomerular filtration rate (GFR) describes the flow rate of filtered fluid through the kidney.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      27.9
      Seconds
  • Question 6 - A medical student is asked to calculate the net pressure difference in a...

    Incorrect

    • A medical student is asked to calculate the net pressure difference in a capillary wall, considering: Interstitial fluid hydrostatic pressure = –3 mmHg, Plasma colloid osmotic pressure = 28 mmHg, Capillary hydrostatic pressure = 17 mmHg, Interstitial fluid colloid osmotic pressure = 8 mmHg, and Filtration coefficient = 1. Which is the correct answer?

      Your Answer: –2 mmHg

      Correct Answer: 0 mmHg

      Explanation:

      The rate of filtration at any point along a capillary depends on a balance of forces sometimes called Starling’s forces after the physiologist who first described their operation in detail. The Starling principle of fluid exchange is key to understanding how plasma fluid (solvent) within the bloodstream (intravascular fluid) moves to the space outside the bloodstream (extravascular space). Fluid movement = k[(pc– pi)–(Πc– Πi)] where k = capillary filtration coefficient, pc = capillary hydrostatic pressure, pi= interstitial hydrostatic pressure, Πc = capillary colloid osmotic pressure, Πi = interstitial colloid osmotic pressure. Therefore: 1 × [capillary hydrostatic pressure (17) – interstitial fluid hydrostatic pressure (–3)] – [plasma colloid osmotic pressure (28) – interstitial fluid colloid osmotic pressure (8)] = 0 mmHg

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      56.5
      Seconds
  • Question 7 - Which of the following conditions may cause hypervolaemic hyponatraemia? ...

    Incorrect

    • Which of the following conditions may cause hypervolaemic hyponatraemia?

      Your Answer: Polycystic Kidney Disease

      Correct Answer: Cirrhosis

      Explanation:

      Hypovolaemic hyponatraemia: reduced extracellular fluid
      Renal loss of sodium and water; urine Na >20 mmol/day
      Causes:
      Diuretic use
      Salt wasting nephropathy
      Cerebral salt wasting
      Mineralocorticoid deficiency/adrenal insufficiency
      Renal tubular acidosis
      Extrarenal loss of sodium and water with renal conservation; urine Na <20 mmol/day
      Causes:
      Burns
      Gastrointestinal loss
      Pancreatitis
      Blood loss
      3rd space loss (bowel obstruction, peritonitis)

      Hypervolaemic hyponatraemia: expanded intracellular fluid and extracellular fluid but reduced effective arterial blood volume
      Causes:
      Congestive cardiac failure
      Cirrhosis
      Nephrotic syndrome

      Euvolaemic hyponatraemia: expanded intracellular and extracellular fluid but oedema absent
      Causes:
      Thiazide diuretics (can be euvolaemic or hypovolaemic)
      Hypothyroidism
      Adrenal insufficiency (can be euvolaemic or hypovolaemic)
      SIADH (cancer, central nervous system disorders, drugs, pulmonary disease, nausea, postoperative pain, HIV, infection, Guillain‐Barre syndrome, acute intermittent porphyria)
      Decreased solute ingestion (beer potomania/tea and toast diet)

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      26.2
      Seconds
  • Question 8 - A patient with this condition has extracellular fluid volume expansion: ...

    Correct

    • A patient with this condition has extracellular fluid volume expansion:

      Your Answer: Nephrotic syndrome

      Explanation:

      Nephrotic syndrome is a syndrome comprising of signs of nephrosis, including proteinuria, hypoalbuminemia, and oedema. It is a component of glomerulonephritis, in which different degrees of proteinuria occur. Essentially, loss of protein through the kidneys leads to low protein levels in the blood , which causes water to be drawn into soft tissues (oedema). Severe hypoalbuminemia can also cause a variety of secondary problems, such as water in the abdominal cavity (ascites), around the heart or lung (pericardial effusion, pleural effusion), high cholesterol, loss of molecules regulating coagulation (hence increased risk of thrombosis). The most common sign is excess fluid in the body due to the serum hypoalbuminemia. Lower serum oncotic pressure causes fluid to accumulate in the interstitial tissues. Sodium and water retention aggravates the oedema.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      13.4
      Seconds
  • Question 9 - A 32-year-old man presented with a metabolic acidosis and increased anion gap. What...

    Incorrect

    • A 32-year-old man presented with a metabolic acidosis and increased anion gap. What is the most likely cause of the changes of the anion gap in this patient?

      Your Answer: Bromide intoxication

      Correct Answer: Lactic acidosis

      Explanation:

      High anion gap in metabolic acidosis is caused generally by the elevation of the levels of acids like ketones, lactate, sulphates in the body, which consume the bicarbonate ions. Other causes of a high anion gap include overdosing on salicylates, uraemia, rhabdomyolysis, hypocalcaemia, hypomagnesaemia, or ingestion of toxins such as ethylene glycol, methanol, propyl alcohol, cyanide and iron.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      18.4
      Seconds
  • Question 10 - A 45 year-old male, with behavioural changes developed euvolemic hyponatraemia. Which of the...

    Incorrect

    • A 45 year-old male, with behavioural changes developed euvolemic hyponatraemia. Which of the following conditions most likely predisposed the patient to develop euvolemic hyponatraemia?

      Your Answer: Salt-losing nephropathy

      Correct Answer: Psychosis

      Explanation:

      In euvolemic hyponatraemia, there is volume expansion in the body, there is no oedema, but hyponatremia occurs. Causes include: state of severe pain or nausea, psychosis, brain trauma, SIADH, hypothyroidism and glucocorticoid deficiency.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      19.9
      Seconds
  • Question 11 - A 45-year-old man with short bowel syndrome requires parenteral nutrition. The solution of...

    Correct

    • A 45-year-old man with short bowel syndrome requires parenteral nutrition. The solution of choice for parenteral nutrition is:

      Your Answer: Crystalline amino acids

      Explanation:

      Total parenteral nutrition (TPN), is the practice of feeding a person intravenously, circumventing the gut. It is normally used in the following situations: surgery, when feeding by mouth is not possible, when a person’s digestive system cannot absorb nutrients due to chronic disease or if a person’s nutrient requirement cannot be met by enteral feeding and supplementation. A sterile bag of nutrient solution, between 500 ml and 4L, is provided. The pump infuses a small amount (0.1–10 ml/h) continuously to keep the vein open. The nutrient solution consists of water, glucose, salts, amino acids, vitamins and sometimes emulsified fats. Ideally each patient is assessed individually before commencing on parenteral nutrition, and a team consisting of doctors, nurses, clinical pharmacists and dietitians evaluate the patient’s individual data and decide what formula to use and at what rate.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      22.7
      Seconds
  • Question 12 - A 56-year-old woman weighs 75 kg. In this patient, total body water, intracellular...

    Incorrect

    • A 56-year-old woman weighs 75 kg. In this patient, total body water, intracellular fluid and extracellular fluid are respectively:

      Your Answer: 40 l, 30 l, 10 l

      Correct Answer: 45 l, 30 l, 15 l

      Explanation:

      The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. The total body water (TBW) content of humans is approximately 60% of body weight. Two-thirds is located in the intracellular and one-third in the extracellular compartment. So, in a 75-kg individual, TBW = 60 × 75/100 = 45 l. Intracellular content = 2/3 × 45 = 30 l and extracellular content = 1/3 × 45 = 15 l.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      18.7
      Seconds
  • Question 13 - Extracellular body fluid as compared with intracellular body fluid: ...

    Incorrect

    • Extracellular body fluid as compared with intracellular body fluid:

      Your Answer: Contains more amino acids

      Correct Answer: Is relatively rich in glucose

      Explanation:

      The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. Ensuring the right amount of body water is part of fluid balance, an aspect of homeostasis. The extracellular fluid (ECF) includes all fluids outside the cells. This fluid can be divided into three fluid departments: interstitial (in the tissue spaces) fluid, blood plasma and lymph, and specialised compartments called transcellular fluid. The extracellular fluid surrounds all the cells in the body and is in equilibrium with the intracellular fluid. So, its composition must remain fairly constant even though substances are passing into and out of the cells. The interstitial fluid, though called a fluid, is in a reality a gel-like composition made up of: water, proteoglycan molecules and collagen. The extracellular fluid constitutes 40% of total body water, with intracellular fluid making up the remaining 60%. It is relatively rich in glucose.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      11.3
      Seconds
  • Question 14 - A 30-year-old woman feels thirsty. This thirst is probably due to: ...

    Incorrect

    • A 30-year-old woman feels thirsty. This thirst is probably due to:

      Your Answer: Decreased level of angiotensin II

      Correct Answer: Increased level of angiotensin II

      Explanation:

      Thirst is the basic need or instinct to drink. It arises from a lack of fluids and/or an increase in the concentration of certain osmolites such as salt. If the water volume of the body falls below a certain threshold or the osmolite concentration becomes too high, the brain signals thirst. Excessive thirst, known as polydipsia, along with excessive urination, known as polyuria, may be an indication of diabetes. Angiotensin II is a hormone that is a powerful dipsogen (i.e. it stimulates thirst) that acts via the subfornical organ. It increases secretion of ADH in the posterior pituitary and secretion of ACTH in the anterior pituitary.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      13.5
      Seconds
  • Question 15 - What is the percentage of bone calcium that is freely exchangeable with the...

    Correct

    • What is the percentage of bone calcium that is freely exchangeable with the extracellular fluid that is available for buffering changes in the calcium ion balance?

      Your Answer: 1%

      Explanation:

      Around 1% of calcium in the body is available for buffering changes in calcium ion balance. These are mainly derived from the bone that are freely exchangeable with extracellular fluid.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      20.9
      Seconds
  • Question 16 - A 43-year-old diabetic man complains of headaches, palpitations, anxiety, abdominal pain and weakness....

    Incorrect

    • A 43-year-old diabetic man complains of headaches, palpitations, anxiety, abdominal pain and weakness. He is administered sodium bicarbonate used to treat:

      Your Answer: Metabolic alkalosis

      Correct Answer: Metabolic acidosis

      Explanation:

      Sodium bicarbonate is indicated in the management of metabolic acidosis, which may occur in severe renal disease, uncontrolled diabetes, circulatory insufficiency due to shock or severe dehydration, extracorporeal circulation of blood, cardiac arrest and severe primary lactic acidosis. Bicarbonate is given at 50-100 mmol at a time under scrupulous monitoring of the arterial blood gas readings. This intervention, however, has some serious complications including lactic acidosis, and in those cases, should be used with great care.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      47.3
      Seconds
  • Question 17 - The blood-brain barrier is a membrane that separates the circulating blood from the...

    Incorrect

    • The blood-brain barrier is a membrane that separates the circulating blood from the brain extracellular fluid in the central nervous system (CNS). Which of the following statements regarding the blood– brain barrier is CORRECT?

      Your Answer: It is more permeable in adults than in infants

      Correct Answer: It breaks down in areas of brain that are infected

      Explanation:

      The blood–brain barrier is a membrane that controls the passage of substances from the blood into the central nervous system. It is a physical barrier between the local blood vessels and most parts of the central nervous system and stops many substances from travelling across it. During meningitis, the blood–brain barrier may be disrupted. This disruption may increase the penetration of various substances (including either toxins or antibiotics) into the brain. A few regions in the brain, including the circumventricular organs, do not have a blood–brain barrier.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      30.4
      Seconds
  • Question 18 - Intracellular shifting of hydrogen ions can generate a metabolic alkalosis. In which of...

    Incorrect

    • Intracellular shifting of hydrogen ions can generate a metabolic alkalosis. In which of the following conditions is metabolic alkalosis caused by this mechanism ?

      Your Answer: Milk-alkali syndrome

      Correct Answer: Hypokalaemia

      Explanation:

      Metabolic alkalosis is characterized by a primary increase in the concentration of serum bicarbonate ions. This may occur as a consequence of a loss of hydrogen ions or a gain in bicarbonate. Hydrogen ions may be lost through the kidneys or the GI tract, as for example during vomiting, nasogastric suction or use of diuretics. Intracellular shifting of hydrogen ions develops mainly during hypokalaemia to maintain neutrality. Gain in bicarbonate ions may develop during administration of sodium bicarbonate in high amounts or in amounts that exceed the capacity of excretion of the kidneys, as seen in renal failure. Fluid losses may be another cause of metabolic alkalosis, causing the reduction of extracellular fluid volume.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      27.5
      Seconds
  • Question 19 - A 47 -year-old male was admitted due to a bleeding peptic ulcer. On...

    Incorrect

    • A 47 -year-old male was admitted due to a bleeding peptic ulcer. On his 3rd hospital day, he developed a cardiac arrhythmia. His serum potassium was markedly elevated. What is the most likely cause of hyperkalaemia in this patient?

      Your Answer: Volume overload

      Correct Answer: Multiple blood transfusions

      Explanation:

      Patients with gastrointestinal bleeding often require blood transfusion. Among the various side effects of blood transfusions, is the increase of potassium levels. The use of stored blood for transfusions is followed by an increase of serum potassium levels. Potassium level increases are more pronounced in patients who receive blood stored for more than 12 d. Furthermore, the lysis and destruction of red blood cells, especially in the transfusion of older PRBCs, can further increase potassium levels. Excessive use of a PPi has been associated with hyperkaelemia however would be less likely in this acute setting.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      15.8
      Seconds
  • Question 20 - A 66 year old male, was involved in a MVA. He sustained third...

    Incorrect

    • A 66 year old male, was involved in a MVA. He sustained third degree burns to his abdomen and open bleeding wound to his left leg. The patient complains of dizziness. He is a known hypertensive but during examination was found to be hypotensive. His heart rate is 120/min, with regular rhythm. What is the possible cause of his hypotension?

      Your Answer: Transfusion reaction

      Correct Answer: Hypovolaemia

      Explanation:

      Hypovolemia can be recognized by tachycardia, diminished blood pressure, and the absence of perfusion as assessed by skin signs (skin turning pale) and/or capillary refill time. The patient may feel dizzy, faint, nauseated, or very thirsty. Common causes of hypovolemia are loss of blood, loss of plasma which occurs in severe burns and lesions discharging fluid, loss of body sodium and consequent intravascular water which may occur in cases of diarrhoea and vomiting. In this case the cause of patients hypotension is due to hypovolemia from both loss of plasma and blood.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      20.7
      Seconds
  • Question 21 - A 27-year-old female was admitted due to severe dehydration. The patient also complained...

    Incorrect

    • A 27-year-old female was admitted due to severe dehydration. The patient also complained of chest tightness, thus an ECG was requested. The ECG strip showed an isoelectric ST segment, upright T wave, with prominent U waves. What is the most likely electrolyte abnormality responsible for these ECG tracing?

      Your Answer: Hypocalcaemia

      Correct Answer: Hypokalaemia

      Explanation:

      U waves are prominent if it is >1-2mm or 25% of the height of the T wave. Abnormally prominent U waves are characteristically seen in severe hypokalaemia.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      23.7
      Seconds
  • Question 22 - The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation,...

    Incorrect

    • The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation, the buffering capacity of the system is at maximum when the number of free anions compared with undissociated acid is:

      Your Answer: Three times more

      Correct Answer: Equal

      Explanation:

      In 1908, Lawrence Joseph Henderson wrote an equation describing the use of carbonic acid as a buffer solution. Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson–Hasselbalch equation. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid–base reactions. Two equivalent forms of the equation are: pH = pKa + log10 [A–]/[HA] or pH = pKa + log10 [base]/[acid]. Here, pKa is − log10(Ka) where Ka is the acid dissociation constant, that is: pKa = –log10(Ka) = –log10 ([H3 O+][A–]/[HA]) for the reaction: HA + H2 O ≈ A– + H3 O+ In these equations, A– denotes the ionic form of the relevant acid. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed. Maximum buffering capacity is found when pH = pKa or when the number of free anions to undissociated acid is equal and buffer range is considered to be at a pH = pKa ± 1.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      14.5
      Seconds
  • Question 23 - A 5-year-old child diagnosed with nephrotic syndrome developed generalised oedema. What is the...

    Incorrect

    • A 5-year-old child diagnosed with nephrotic syndrome developed generalised oedema. What is the mechanism for the development of oedema in patients with nephrotic syndrome?

      Your Answer: Increased capillary hydrostatic pressure

      Correct Answer: Decreased colloid osmotic pressure

      Explanation:

      The development of oedema in nephrotic syndrome has traditionally been viewed as an underfill mechanism. According to this view, urinary loss of protein results in hypoalbuminemia and decreased plasma oncotic pressure. As a result, plasma water translocates out of the intravascular space and results in a decrease in intravascular volume. In response to the underfilled circulation, effector mechanisms are then activated that signal the kidney to secondarily retain salt and water. While an underfill mechanism may be responsible for oedema formation in a minority of patients, recent clinical and experimental findings would suggest that oedema formation in most nephrotic patients is the result of primary salt retention. Direct measurements of blood and plasma volume or measurement of neurohumoral markers that indirectly reflect effective circulatory volume are mostly consistent with either euvolemia or a volume expanded state. The ability to maintain plasma volume in the setting of a decreased plasma oncotic pressure is achieved by alterations in transcapillary exchange mechanisms known to occur in the setting of hypoalbuminemia that limit excessive capillary fluid filtration.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      10.2
      Seconds
  • Question 24 - Diffusion is the movement of molecules from a region of high concentration to a...

    Incorrect

    • Diffusion is the movement of molecules from a region of high concentration to a region of low concentration. Which of these changes will decrease the rate of diffusion of a substance?

      Your Answer: An increase in membrane permeability

      Correct Answer: An increase in the molecular weight of the substance

      Explanation:

      Unless given IV, a drug must cross several semipermeable cell membranes before it reaches the systemic circulation. Drugs may cross cell membranes by diffusion, amongst other mechanisms. The rate of diffusion of a substance is proportional to the difference in the concentration of the diffusing substance between the two sides of the membrane, the temperature of the solution, the permeability of the membrane and, in the case of ions, the electrical potential difference between the two sides of the membrane.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      16.7
      Seconds
  • Question 25 - Which of the following abnormalities can be seen in patients with hypermagnesemia? ...

    Incorrect

    • Which of the following abnormalities can be seen in patients with hypermagnesemia?

      Your Answer: Anorexia

      Correct Answer: Respiratory depression

      Explanation:

      Hypermagnesemia is an electrolyte disturbance in which there is a high level of magnesium in the blood. It is defined as a level greater than 1.1 mmol/L. Symptoms include weakness, confusion, decreased breathing rate, and cardiac arrest.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      7.7
      Seconds
  • Question 26 - A 31 -year-old female patient had a blood gas done on presentation to...

    Incorrect

    • A 31 -year-old female patient had a blood gas done on presentation to the emergency department. She was found to have a metabolic acidosis and decreased anion gap. The most likely cause of these findings in this patient would be?

      Your Answer: Hypomagnesaemia

      Correct Answer: Hypoalbuminemia

      Explanation:

      A low anion gap might be caused by alterations in serum protein levels, primarily albumin (hypoalbuminemia), increased levels of calcium (hypercalcaemia) and magnesium (hypermagnesemia) or bromide and lithium intoxication. However, the commonest cause is hypoalbuminemia, thus if the albumin concentration falls, the anion gap will also be lower. The anion gap should be corrected upwards by 2.5 mmol/l for every 10g/l fall in the serum albumin.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      11.5
      Seconds
  • Question 27 - Which of the following is an anion? ...

    Incorrect

    • Which of the following is an anion?

      Your Answer: Sodium

      Correct Answer: Phosphate

      Explanation:

      Cations: sodium, magnesium, calcium and potassium

      Anions: chloride, phosphate, bicarbonate, lactate, sulphate and albumin

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Physiology
      10.9
      Seconds
  • Question 28 - A patient with chronic renal disease, missed a day of his dialysis schedule.,...

    Incorrect

    • A patient with chronic renal disease, missed a day of his dialysis schedule., His serum potassium was 7.6 mmol/L when his electrolytes were checked. What is the ECG finding expected in this patient?

      Your Answer: Prolonged QT interval

      Correct Answer: Tented T waves

      Explanation:

      ECG characteristics of hyperkalaemia may show the following changes: P-waves are widened and of low amplitude due to slowing of conduction, widened QRS complex, QRS-T fusion, loss of ST segment and tall tented T waves.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      26.3
      Seconds
  • Question 29 - A child presents with hypertension. Serum potassium analysis shows hypokalaemia. What is the...

    Incorrect

    • A child presents with hypertension. Serum potassium analysis shows hypokalaemia. What is the most likely diagnosis?

      Your Answer:

      Correct Answer: Liddle syndrome

      Explanation:

      Liddle’s syndrome,  is an autosomal dominant disorder, that is characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule. Bartter Syndrome also presents with hypokalaemia, however blood pressure of these patients is usually low or normal.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      0
      Seconds
  • Question 30 - A 62-year-old male patient in the intensive care unit was found to have...

    Incorrect

    • A 62-year-old male patient in the intensive care unit was found to have a low serum phosphate level. What is the serum level of phosphate which is considered as normal in adults?

      Your Answer:

      Correct Answer: 0.8–1.45 mmol/l

      Explanation:

      After calcium, phosphorus is the most plentiful mineral in the human body. It is an important and vital element which our body needs to complete many physiologic processes , such as filtering waste and repairing cells. Phosphorus helps with bone growth and approximately 85% of phosphate in the body is contained in bone. Phosphate is involved in energy storage, and nerve and muscle production. A normal range of plasma phosphate in adults teenagers generally from 0.8 mmol/l to 1.45 mmol/l. The normal range varies depending on age. Infants and children have higher phosphorus levels because more of this mineral is needed for their normal growth and bone development.

    • This question is part of the following fields:

      • Fluids & Electrolytes
      • Pathology
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Fluids & Electrolytes (14/28) 50%
Physiology (6/12) 50%
Pathology (8/16) 50%
Passmed