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  • Question 1 - Post-total gastrectomy, there will be a decreased production of which of the following...

    Correct

    • Post-total gastrectomy, there will be a decreased production of which of the following enzymes?

      Your Answer: Pepsin

      Explanation:

      Pepsin is a protease that is released from the gastric chief cells and acts to degrade proteins into peptides. Released as pepsinogen, it is activated by hydrochloric acid and into pepsin itself. Gastrin and the vagus nerve trigger the release of pepsinogen and HCl when a meal is ingested. Pepsin functions optimally in an acidic environment, especially at a pH of 2.

    • This question is part of the following fields:

      • Gastroenterology
      • Physiology
      5.8
      Seconds
  • Question 2 - After total thyroidectomy, which of the following investigations is recommended in the immediate...

    Incorrect

    • After total thyroidectomy, which of the following investigations is recommended in the immediate post-operative period?

      Your Answer: Thyroid-stimulating hormone

      Correct Answer: Serum calcium

      Explanation:

      Total thyroidectomy might sometimes result in inadvertent excision or damage of parathyroid glands, leading to hypoparathyroidism. Monitoring serum calcium levels in the post-operative period to detect hypocalcaemia is essential to diagnose and prevent this condition.

    • This question is part of the following fields:

      • Endocrine
      • Pathology
      10.1
      Seconds
  • Question 3 - Which of the following structure contains the parasympathetic pre-ganglionic nucleus that innervates the...

    Incorrect

    • Which of the following structure contains the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle?

      Your Answer: Ciliary ganglion

      Correct Answer: Edinger–Westphal nucleus

      Explanation:

      The Edinger–Westphal nucleus (accessory oculomotor nucleus) is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle.

    • This question is part of the following fields:

      • Anatomy
      • Head & Neck
      10.6
      Seconds
  • Question 4 - Nephrotic syndrome is a condition that causes proteinuria, hypoalbuminemia and oedema. Which of...

    Correct

    • Nephrotic syndrome is a condition that causes proteinuria, hypoalbuminemia and oedema. Which of the following is the cause of the oedema in these patients?

      Your Answer: Decreased oncotic pressure

      Explanation:

      The glomeruli of the kidneys are the parts that normally filter the blood. They consist of capillaries that are fenestrated and allow fluid, salts and other small solutes to flow through, but normally not proteins. In nephrotic syndrome, the glomeruli become damaged allowing small proteins, such as albumin to pass through the kidneys into urine. Oedema usually occurs due to salt and water retention by the diseased kidneys as well as due to the reduced colloid oncotic pressure (because of reduced albumin in the plasma). Lower serum oncotic pressure causes fluid to accumulate in the interstitial tissues.

    • This question is part of the following fields:

      • Physiology
      • Renal
      18.2
      Seconds
  • Question 5 - The pudendal nerve is derived from? ...

    Incorrect

    • The pudendal nerve is derived from?

      Your Answer: L5, S1, S2

      Correct Answer: S2, S3, S4

      Explanation:

      The pudendal nerve derives it’s fibres from the ventral branches of the second, third and fourth sacral nerves (S2,3,4)

    • This question is part of the following fields:

      • Anatomy
      • Pelvis
      5.6
      Seconds
  • Question 6 - A 24 year old mother is breastfeeding her first child. Which of the...

    Incorrect

    • A 24 year old mother is breastfeeding her first child. Which of the following cellular adaptations occurred in her breast tissue to allow her to do this?

      Your Answer: Ductal epithelial metaplasia

      Correct Answer: Lobular hyperplasia

      Explanation:

      Under the influence of oestrogen in pregnancy, there is an increase in the number of lobules which will facilitate lactation.

      Steatocytes occur due to loss of weight and nutritional deficit.

      Metaplasia is a normal physiological process which is due to a change in normal epithelium with another type.

      Lobular atrophy will result in a decreased capacity to provide milk.

    • This question is part of the following fields:

      • Cell Injury & Wound Healing; Female Health
      • Pathology
      12.2
      Seconds
  • Question 7 - Whipple's procedure involves mobilizing the head of the pancreas. As the surgeon does...

    Correct

    • Whipple's procedure involves mobilizing the head of the pancreas. As the surgeon does this, he must be careful to avoid injury to a key structure that is found lying behind the head of the pancreas. Which vital structure is this?

      Your Answer: Common bile duct

      Explanation:

      The posterior relations of the head of the pancreas include: the inferior vena cava, the common bile duct, the renal veins, the right crus of the diaphragm and the aorta.

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      8.8
      Seconds
  • Question 8 - A 49-year-old woman with acute renal failure has a total plasma [Ca2+] =...

    Incorrect

    • A 49-year-old woman with acute renal failure has a total plasma [Ca2+] = 2. 5 mmol/l and a glomerular filtration rate of 160 l/day. What is the estimated daily filtered load of calcium?

      Your Answer: 550 mmol/day

      Correct Answer: 240 mmol/day

      Explanation:

      Calcium is the most abundant mineral in the human body. The average adult body contains in total approximately 1 kg of calcium of which 99% is in the skeleton in the form of calcium phosphate salts. The extracellular fluid (ECF) contains approximately 22 mmol, of which about 9 mmol is in the plasma. About 40% of total plasma Ca2+ is bound to proteins and not filtered at the glomerular basement membrane. Therefore, the estimated daily filtered load is 1.5 mmol/l × 160 l/day = 240 mmol/day. The exact amount of free versus total Ca2+ depends on the blood pH: free Ca2+ increases during acidosis and decreases during alkalosis.

    • This question is part of the following fields:

      • Physiology
      • Renal
      16.5
      Seconds
  • Question 9 - A 70-year-old man who was previously healthy develops a rapidly progressing neurological deficit....

    Incorrect

    • A 70-year-old man who was previously healthy develops a rapidly progressing neurological deficit. A MRI reveals a large, poorly defined mass with central necrosis in his left temporal lobe. What is the most likely diagnosis?

      Your Answer: Low-grade astrocytoma

      Correct Answer: Glioblastoma multiforme

      Explanation:

      Glioblastoma multiforme, or grade 4 astrocytoma, is the most common and aggressive primary brain tumour. They are formed by small areas of necrotising tissue surrounded by highly anaplastic cells. Most of them arise from the deep white matter of the brain and quickly infiltrate it, becoming very large before they are symptomatic. The most common symptom is progressive memory, personality or neurological deficit due to temporal and frontal lobe involvement. It is most common in men, and risk factors include: neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome, and Turcot syndrome.

    • This question is part of the following fields:

      • Neurology
      • Pathology
      14.4
      Seconds
  • Question 10 - A 36-year-old woman suddenly suffers from a generalized seizure. She was previously healthy....

    Incorrect

    • A 36-year-old woman suddenly suffers from a generalized seizure. She was previously healthy. An emergency CT scan reveals a mass in the posterior fossa, with distortion of the lateral ventricles. After removing the tumour, the biopsy reveals it contains glial fibrillary acidic protein (GEAP). What's the most likely diagnosis?

      Your Answer: Neuroblastoma

      Correct Answer: Astrocytoma

      Explanation:

      Astrocytomas are primary intracranial tumours derived from astrocyte cells of the brain. They can arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve and, rarely, in the spinal cord. These tumours express glial fibrillary acidic protein (GFAP). In almost half of cases, the first symptom of an astrocytoma is the onset of a focal or generalised seizure. Between 60% and 75% of patients will have recurrent seizures during the course of their illness. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) cause by the direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume. CT will usually show distortion of the third and lateral ventricles, with displacement of the anterior and middle cerebral arteries. Histological diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumour.

    • This question is part of the following fields:

      • Neurology
      • Pathology
      18.8
      Seconds
  • Question 11 - Which of the following structure forms the floor of the posterior triangle of...

    Incorrect

    • Which of the following structure forms the floor of the posterior triangle of the neck:

      Your Answer: Investing fascia

      Correct Answer: Prevertebral fascia

      Explanation:

      The posterior triangle (or lateral cervical region) is a region of the neck which has the following boundaries:
      Apex: Union of the sternocleidomastoid and the trapezius muscles at the superior nuchal line of the occipital bone
      Anterior: Posterior border of the sternocleidomastoid muscle
      Posterior: Anterior border of the trapezius
      Base: Middle one third of the clavicle
      Roof: Investing layer of the deep cervical fascia
      Floor: The anterolateral portion of prevertebral fascia

    • This question is part of the following fields:

      • Anatomy
      • Head & Neck
      40.7
      Seconds
  • Question 12 - Leakage from a silicone breast implant can lead to: ...

    Incorrect

    • Leakage from a silicone breast implant can lead to:

      Your Answer: Breast abscess

      Correct Answer: Pain and contracture

      Explanation:

      Breast implants are mainly: saline-filled and silicone gel-filled. Complications include haematoma, fluid collections, infection at the surgical site, pain, wrinkling, asymmetric appearance, wound dehiscence and thinning of the breast tissue.

    • This question is part of the following fields:

      • Pathology
      • Women's Health
      7.5
      Seconds
  • Question 13 - A 60-year-old female has sudden onset of high-grade fever associated with cough with...

    Correct

    • A 60-year-old female has sudden onset of high-grade fever associated with cough with productive rusty-coloured sputum. Chest x-ray showed left-sided consolidation. What is the most accurate test for the diagnosis of this patient?

      Your Answer: Sputum culture

      Explanation:

      Sputum culture is used to detect and identify the organism that are infecting the lungs or breathing passages.

    • This question is part of the following fields:

      • Microbiology
      • Pathology
      14.3
      Seconds
  • Question 14 - Bloody discharge from the nipple of a 40-year old woman with no obvious...

    Correct

    • Bloody discharge from the nipple of a 40-year old woman with no obvious lump or abnormality on mammography is suggestive of:

      Your Answer: Intraductal papilloma

      Explanation:

      A small benign tumour, namely intraductal papilloma is most common in women between 35-55 years of age. It is also the commonest cause of spontaneous discharge from a single duct. A lump below the nipple may be sometimes palpable. Ultrasound and ductography are useful investigations., along with cytology of discharge to assess the presence of malignant cells. Confirmation is by breast biopsy.

    • This question is part of the following fields:

      • Pathology
      • Women's Health
      8.4
      Seconds
  • Question 15 - What is the most likely cause of bilateral gynaecomastia in a 55-year old...

    Correct

    • What is the most likely cause of bilateral gynaecomastia in a 55-year old male?

      Your Answer: Hepatic failure

      Explanation:

      Hypertrophy of breast tissue in males is known as gynaecomastia. It is normally due to proliferation of stroma and not of mammary ducts. Physiological gynaecomastia can occur during puberty and is often transient, bilateral, symmetrical and possibly tender. Gynaecomastia can occur during old age too, but is usually unilateral. Other causes include hepatic or renal failure, endocrinological disorders, drugs (anabolic steroids, antineoplastic drugs, calcium channel blockers, cimetidine, digitalis, oestrogens, isoniazid, ketoconazole, methadone, metronidazole, reserpine, spironolactone, theophylline), and marijuana. It should not be confused with malignancy which is often hard, asymmetric and fixed to the dermis or fascia. Treatment if indicated, includes withdrawal of the causative factor or treatment of the underlying disorder.

    • This question is part of the following fields:

      • Pathology
      • Women's Health
      7.8
      Seconds
  • Question 16 - An explorative laparotomy is done on a 23 year old following a gunshot...

    Incorrect

    • An explorative laparotomy is done on a 23 year old following a gunshot abdominal injury through the right iliac fossa. It is found that the ileocolic artery is severed and the bullet had perforated the caecum. From which branch does the ileocolic artery originate?

      Your Answer: Coeliac artery

      Correct Answer: Superior mesenteric artery

      Explanation:

      Ileocolic artery branches off from the superior mesenteric artery. It then divides to give a superior and inferior branch.

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      21.1
      Seconds
  • Question 17 - Which muscle is most likely to be affected following an injury to the...

    Correct

    • Which muscle is most likely to be affected following an injury to the thoracodorsal nerve (C6-C8)?

      Your Answer: Latissimus dorsi

      Explanation:

      Latissimus dorsi is a triangular, flat muscle that covers the lumbar region and the lower half of the thoracic region. It is supplied by the sixth, seventh and eighth cervical nerves through the thoracodorsal (long subscapular) nerve.

    • This question is part of the following fields:

      • Anatomy
      • Thorax
      5.5
      Seconds
  • Question 18 - In a splenectomy procedure, special care is emphasized on the preservation of the...

    Incorrect

    • In a splenectomy procedure, special care is emphasized on the preservation of the tail of the pancreas that is closely associated with the spleen to avoid post operative pancreatic fistula. As a general surgeon conducting a splenectomy where are you most likely to find the tail of the pancreas in the abdominal cavity?

      Your Answer: Gastrocolic ligament

      Correct Answer: Splenorenal ligament

      Explanation:

      The tail of the pancreas is the only intraperitoneal part of the pancreas and is found contained in the splenorenal ligament of the peritoneal cavity. The splenorenal ligament is derived from the peritoneum where the wall of the general peritoneal cavity connects to the omental bursa between the spleen and the left kidney. This ligament contains the splenic vessels and the tail of the pancreas.

      The gastrocolic ligament stretches from the greater curvature of the stomach to the transverse colon, connecting the two.

      The gastrosplenic ligament is derived from the greater omentum and is the structure that connects the stomach to the hilum of the spleen. The gastrosplenic ligament continues from the splenic flexure of the colon to the diaphragm and acts as a support to the spleen.

      The transverse colon is connected to the abdominal wall by the mesocolon ligament.

      The falciform ligament on the other hand, attaches the liver to the ventral wall of the abdomen.

      The hepatoduodenal ligament connects the porta hepatis of the liver to the superior part of the duodenum.

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      97.8
      Seconds
  • Question 19 - A 55-year-old male chronic smoker is diagnosed with non-small-cell cancer. His right lung...

    Incorrect

    • A 55-year-old male chronic smoker is diagnosed with non-small-cell cancer. His right lung underwent complete atelectasis and he has a 7cm tumour involving the chest wall. What is the stage of the lung cancer of this patient?

      Your Answer: T4

      Correct Answer: T3

      Explanation:

      Non-small-cell lung cancer is staged through TNM classification. The stage of this patient is T3 because based on the TNM classification the tumour is staged T3 if > 7 cm or one that directly invades any of the following: Chest wall (including superior sulcus tumours), diaphragm, phrenic nerve, mediastinal pleura, or parietal pericardium; or the tumour is in the main bronchus < 2 cm distal to the carina but without involvement of the carina, Or it is associated with atelectasis/obstructive pneumonitis of the entire lung or separate tumour nodule(s) in the same lobe.

    • This question is part of the following fields:

      • Neoplasia
      • Pathology
      5.9
      Seconds
  • Question 20 - Which of the following organs of the abdominal cavity is completely covered by...

    Incorrect

    • Which of the following organs of the abdominal cavity is completely covered by the peritoneum?

      Your Answer: Pancreas

      Correct Answer: Spleen

      Explanation:

      Of the organs listed, the spleen is the only organ that is completely intraperitoneal, that is entirely in the peritoneum. Other completely intraperitoneal organs include the stomach, liver, appendix and the small intestines. The kidney, Inferior vena cava, aorta and the suprarenal glands are all retroperitoneal organs. The pancreas and the duodenum are partially retroperitoneal, with the tail of the pancreas in the peritoneum found in the splenorenal ligament while only the first part of the duodenum is intraperitoneal. For the intraperitoneal organs remember SALTD SPRSS
      S = Stomach
      A = Appendix
      L = Liver
      T = Transverse colon
      D = Duodenum (only the 1st part)
      S = Small intestines
      P = Pancreas (only the tail)
      R = Rectum (only the upper 3rd)
      S = Sigmoid colon
      S = Spleen
      For retroperitoneal, just remember SADPUCKER:
      S = suprarenal glands
      A = Aorta and IVC
      D = Duodenum (all but the 1st part)
      P = Pancreas (all but the tail)
      U = Ureter and bladder
      C = Colon (ascending and descending)
      K = Kidneys
      E = Oesophagus
      R = Rectum (Lower two-thirds)
      For secondarily retroperitoneal remember ‘Pussy Cat Dolls“:
      P = Pancreas
      C = Colon (only ascending and descending)
      D = Duodenum (only parts 2-4)

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      7.2
      Seconds
  • Question 21 - In which situation is a stretch reflex such as knee jerk likely to...

    Correct

    • In which situation is a stretch reflex such as knee jerk likely to be exaggerated?

      Your Answer: In upper motor neuron lesion

      Explanation:

      A stretch reflex is a monosynaptic reflex that causes muscle contraction in response to stretching within that muscle. The sensory apparatus in a muscle that are sensitive to stretch are the muscle spindles. The patellar (knee jerk) reflex is an example. In upper motor neuron lesions, the stretch reflexes tend to be brisk due to loss of inhibitory signals on gamma neurons through the lateral reticulospinal tract.

    • This question is part of the following fields:

      • Neurology
      • Physiology
      9.2
      Seconds
  • Question 22 - A 65-year-old man with no history of smoking complains of shortness of breath...

    Incorrect

    • A 65-year-old man with no history of smoking complains of shortness of breath and persistent cough over the past 8 months. He reveals that in the 1960s he worked for several years as a boiler operator. Chest X-ray shows diffuse lung infiltrates. Which of the following is the most probable cause of these findings?

      Your Answer: Silicosis

      Correct Answer: Asbestosis

      Explanation:

      Asbestosis is a chronic lung disease which leads to long-term respiratory complications and is caused by the inhalation of asbestos fibres. Symptoms due to long exposure to asbestos usually appear 10 to 40 years after initial exposure and include shortness of breath, cough, weight loss, clubbing of the fingers and chest pain. Typical chest X-ray findings include diffuse lung infiltrates that cause the appearance of shaggy heart borders.

    • This question is part of the following fields:

      • Pathology
      • Respiratory
      13.3
      Seconds
  • Question 23 - If a 70-year-old man with known atrial fibrillation dies suddenly, which of these...

    Correct

    • If a 70-year-old man with known atrial fibrillation dies suddenly, which of these is the most likely cause of death?

      Your Answer: Thromboembolism

      Explanation:

      In atrial fibrillation, the abnormal atrial contraction can cause blood to stagnate in the left atrium and form a thrombus, which may then embolize. The patient’s history of AF suggest an embolic disease, which lead to his death.

    • This question is part of the following fields:

      • Cardiovascular
      • Pathology
      9.7
      Seconds
  • Question 24 - A diabetic 58-year-old man, after the injection of radiographic contrast, has a decreased...

    Correct

    • A diabetic 58-year-old man, after the injection of radiographic contrast, has a decreased urine output and decreased level of consciousness. Which of the following conditions has he most likely developed

      Your Answer: Acute tubular necrosis

      Explanation:

      Acute tubular necrosis (ATN) involves damage to the tubule cells of the kidneys and is the most common cause of acute kidney injury. ATN in the majority of the cases is caused by ischaemia of the kidneys due to lack of perfusion and oxygenation but it may also occur due to poison or harmful substance. Contrast used for radiology may cause ATN in patients with several risk factors e.g. diabetic nephropathy. Symptoms may include oliguria, nausea, fluid retention, fatigue and decreased consciousness.

    • This question is part of the following fields:

      • Pathology
      • Renal
      20.6
      Seconds
  • Question 25 - A 53 year old women with a history of atrial fibrillation developed an...

    Incorrect

    • A 53 year old women with a history of atrial fibrillation developed an acute abdomen. On laparoscopic examination her bowels appeared to be dusky to red-purple in colour and her mesenteric veins appeared to be patent. Which of the following is most likely to occur in this situation?

      Your Answer: Liquefactive gangrene

      Correct Answer: Wet gangrene

      Explanation:

      Infarction of the small bowel following a sudden and complete occlusion of the mesenteric artery can involve any portion of the bowel, whether small or a large. The splenic flexure is at most risk for infarction as it is the watershed area between the superior and inferior mesenteric vessels. Regardless of whether the arterial or the venous blood vessels are occluded, because of the blood reflow into the damaged portion, it will appear haemorrhagic. The bowel appearing congested at first and then becoming oedematous. If the artery is occluded then there will be a clear cut demarcation and in venous occlusion the dusky colour fades with the rest of the normal bowel. Wet gangrene is characteristic of ischaemic injury to the gut.

    • This question is part of the following fields:

      • Cell Injury & Wound Healing; Gastrointestinal
      • Pathology
      18
      Seconds
  • Question 26 - A 40-year old gentleman, known with a history of peptic ulcer disease, was...

    Correct

    • A 40-year old gentleman, known with a history of peptic ulcer disease, was brought to the clinic in a dehydrated state with persistent vomiting. His blood investigations revealed:
      • sodium = 142 mmol/l
      • potassium = 2.6 mmol/l
      • chloride = 85 mmol/l
      • pH = 7.55
      • p(CO2) = 50 mmHg
      • p(O2) = 107 mmHg
      • standard bicarbonate = 40 mmol/l
      This patient has a:

      Your Answer: Metabolic alkalosis

      Explanation:

      High pH with high standard bicarbonate indicates metabolic alkalosis. The pa(CO2) was appropriately low in compensation. This is hypokalaemic hypochloraemic metabolic acidosis due to prolonged vomiting. Treatment includes treating the cause and intravenous sodium chloride with potassium.

    • This question is part of the following fields:

      • Physiology
      • Respiratory
      13
      Seconds
  • Question 27 - A 60-year old woman who has a left sided post-pneumonic effusion, was to...

    Correct

    • A 60-year old woman who has a left sided post-pneumonic effusion, was to have some pleural fluid aspirated for culture and sensitivity. If the medical intern in charge of the procedure decided to aspirate while the patient is sitting up on her bed, where in the pleural cavity would the fluid tend to accumulate?

      Your Answer: Costodiaphragmatic recess

      Explanation:

      The lowest part of the pleural cavity is the costodiaphragmatic recess and it the space in which the pleural fluid will accumulate when the patient sits up.

      The cupola is part of the pleural cavity that extends into the root of the neck above the first rib.

      The costomediastinal recess is the junction at which the costal pleura becomes the mediastinal pleura.

      The middle mediastinum is the part of the mediastinum that is occupied by the heart.

      The hilar reflection is the point where the mediastinal pleura is reflected to continue on as the visceral pleura.

    • This question is part of the following fields:

      • Anatomy
      • Thorax
      22.4
      Seconds
  • Question 28 - A 25 year-old female medical student presents with fever, lack of appetite, rashes,...

    Correct

    • A 25 year-old female medical student presents with fever, lack of appetite, rashes, sore throat and lymphadenopathy. Peripheral smear shows atypical lymphocytes. Which is the most likely organism responsible for this patient's condition?

      Your Answer: Epstein–Barr virus

      Explanation:

      Epstein-Barr virus is in the herpes family of viruses and most people will become infected with EBV sometime during their lives. EBV commonly causes infectious mononucleosis, or mono, a contagious viral illness that initially attacks the lymph nodes in the neck and throat. When these tissues become less effective in fighting infection, sore throats, swelling of the nodes and fever may result.

    • This question is part of the following fields:

      • Microbiology
      • Pathology
      8.5
      Seconds
  • Question 29 - Which of the following accumulates within a cell due to the aging process?...

    Correct

    • Which of the following accumulates within a cell due to the aging process?

      Your Answer: Lipofuscin

      Explanation:

      Lipofuscin , also known as lipochrome, is a wear and tear pigment or an aging pigment. It represents free radical injury or lipid peroxidation. On microscopic examination is appears as a yellowish brown pigment around the nucleus (perinuclear pigment). It is often seen in cells which are undergoing regressive changes, commonly in the liver and heart of old patients or patients with cancer, cachexia or severe malnutrition.

    • This question is part of the following fields:

      • Cell Injury & Wound Healing
      • Pathology
      8.4
      Seconds
  • Question 30 - 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
      7.2
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Gastroenterology (1/1) 100%
Physiology (4/5) 80%
Endocrine (0/1) 0%
Pathology (8/16) 50%
Anatomy (3/9) 33%
Head & Neck (0/2) 0%
Renal (2/3) 67%
Pelvis (0/1) 0%
Cell Injury & Wound Healing; Female Health (0/1) 0%
Abdomen (1/4) 25%
Neurology (1/3) 33%
Women's Health (2/3) 67%
Microbiology (2/2) 100%
Thorax (2/2) 100%
Neoplasia (0/1) 0%
Respiratory (1/2) 50%
Cardiovascular (1/1) 100%
Cell Injury & Wound Healing; Gastrointestinal (0/1) 0%
Cell Injury & Wound Healing (1/1) 100%
Fluids & Electrolytes (1/1) 100%
Passmed