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Question 1
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A 75-year-old woman is recuperating from an inguinal hernia surgery when she experiences a severe ischemic stroke. She is being treated on the rehabilitation ward. Nevertheless, she is still unable to eat securely, and multiple swallowing evaluations have revealed that she has a tendency to aspirate. What is the most suitable alternative for long-term feeding?
Your Answer: PEG tube feeding
Explanation:Although PEG tubes are linked to a considerable amount of morbidity, they are the most suitable choice for a long-term solution. A feeding jejunostomy necessitates the use of general anesthesia. TPN is not a viable alternative. Long-term nasogastric feeding is typically inadequate.
Enteral feeding is a method of providing nutrition to patients who are malnourished or at risk of malnutrition and have a functional gastrointestinal tract. It involves administering food directly into the stomach through a tube, which can be placed either through the nose (nasogastric tube) or directly into the stomach (gastrostomy tube). The type of tube used depends on the patient’s condition and the presence of upper gastrointestinal dysfunction.
To ensure safe and effective enteral feeding, healthcare professionals must check the placement of the tube using aspiration and pH tests. Gastric feeding is preferred, but if there is upper GI dysfunction, duodenal or jejunal tubes may be used. Patients in intensive care units (ICUs) should receive continuous feeding for 16-24 hours, and a motility agent may be used to aid gastric emptying. If this is ineffective, post-pyloric feeding or parenteral feeding may be considered.
Complications of enteral feeding include diarrhoea, aspiration, hyperglycaemia, and refeeding syndrome. Patients who are identified as malnourished or at risk of malnutrition should be considered for enteral feeding, especially if they have a BMI below 18.5 kg/m2, unintentional weight loss of more than 10% over 3-6 months, or a BMI below 20 kg/m2 and unintentional weight loss of more than 5% over 3-6 months. Surgical patients who are malnourished, have an unsafe swallow or inadequate oral intake, and have a functional GI tract may benefit from preoperative enteral feeding.
It is important to note that PEG tubes should not be removed until at least 2 weeks after insertion, and surgical patients due to have major abdominal surgery should be carefully evaluated before enteral feeding is initiated. Overall, enteral feeding is a valuable tool for providing nutrition to patients who are unable to eat normally, but it must be used with caution and under the guidance of a healthcare professional.
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This question is part of the following fields:
- Surgery
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Question 2
Correct
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A 52-year-old man is shot in the abdomen and suffers a significant intra-abdominal injury. He undergoes a laparotomy, bowel resection, and end colostomy, and requires a 6-unit blood transfusion due to an associated vascular injury. After a prolonged recovery, he is paralyzed and ventilated for 2 weeks in the intensive care unit. He is given total parenteral nutrition and eventually weaned off the ventilator and transferred to the ward. During a routine blood test, the following results are observed:
Full blood count
Hb 11.3 g/dl
Platelets 267 x 109/l
WBC 10.1 x109/l
Urea and electrolytes
Na+ 131 mmol/l
K+ 4.6 mmol/l
Urea 2.3 mmol/l
Creatinine 78 µmol/l
Liver function tests
Bilirubin 25 µmol/l
ALP 445 u/l
ALT 89 u/l
γGT 103 u/l
What is the most probable underlying cause for the noted abnormalities?Your Answer: Total parenteral nutrition
Explanation:Liver function tests are often affected by TPN, which can cause cholestasis but it is unlikely to lead to the formation of gallstones as seen in the image. While blood transfusion reactions may cause hepatitis, they usually present earlier and with changes in haemoglobin, which is rare in modern times.
Understanding Total Parenteral Nutrition
Total parenteral nutrition is a commonly used method of providing nutrition to surgical patients who are nutritionally compromised. The bags used in this method contain a combination of glucose, lipids, and essential electrolytes, with the exact composition being determined by the patient’s nutritional requirements. While it is possible to infuse this nutrition peripherally, doing so may result in thrombophlebitis. As such, longer-term infusions should be administered into a central vein, preferably via a PICC line.
Complications associated with total parenteral nutrition are related to sepsis, refeeding syndromes, and hepatic dysfunction. It is important to monitor patients closely for any signs of these complications and adjust the nutrition accordingly. By understanding the basics of total parenteral nutrition, healthcare professionals can provide optimal care to their patients and ensure their nutritional needs are being met.
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This question is part of the following fields:
- Surgery
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Question 3
Incorrect
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What is the most frequent kind of kidney stone?
Your Answer: Calcium phosphate
Correct Answer: Calcium oxalate
Explanation:Types of Renal Stones and their Appearance on X-ray
Renal stones, also known as kidney stones, are solid masses that form in the kidneys due to the accumulation of certain substances. There are different types of renal stones, each with a unique appearance on x-ray. Calcium oxalate stones are the most common, accounting for 40% of cases, and appear opaque on x-ray. Mixed calcium oxalate/phosphate stones and calcium phosphate stones also appear opaque and make up 25% and 10% of cases, respectively. Triple phosphate stones, which develop in alkaline urine and are composed of struvite, account for 10% of cases and appear opaque as well. Urate stones, which are radiolucent, make up 5-10% of cases. Cystine stones, which have a semi-opaque, ‘ground-glass’ appearance, are rare and only account for 1% of cases. Xanthine stones are the least common, accounting for less than 1% of cases, and are also radiolucent. Stag-horn calculi, which involve the renal pelvis and extend into at least 2 calyces, are composed of triple phosphate and are more likely to develop in alkaline urine. Infections with Ureaplasma urealyticum and Proteus can increase the risk of their formation.
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This question is part of the following fields:
- Surgery
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Question 4
Incorrect
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A 55-year-old woman arrives at the emergency department with a sudden and severe headache, which she describes as the worst she has ever experienced. The headache came on while she was sitting at her desk. She also reports feeling nauseous and vomiting.
During the examination, the woman displays neck stiffness, photophobia, and appears drowsy. A CT scan reveals hyperdense across the basal cisterns and sulci.
What is the appropriate course of action for managing the complications of this condition?Your Answer: Nifedipine
Correct Answer: Nimodipine
Explanation:A subarachnoid haemorrhage (SAH) is a type of bleeding that occurs within the subarachnoid space of the meninges in the brain. It can be caused by head injury or occur spontaneously. Spontaneous SAH is often caused by an intracranial aneurysm, which accounts for around 85% of cases. Other causes include arteriovenous malformation, pituitary apoplexy, and mycotic aneurysms. The classic symptoms of SAH include a sudden and severe headache, nausea and vomiting, meningism, coma, seizures, and ECG changes.
The first-line investigation for SAH is a non-contrast CT head, which can detect acute blood in the basal cisterns, sulci, and ventricular system. If the CT is normal within 6 hours of symptom onset, a lumbar puncture is not recommended. However, if the CT is normal after 6 hours, a lumbar puncture should be performed at least 12 hours after symptom onset to check for xanthochromia and other CSF findings consistent with SAH. If SAH is confirmed, referral to neurosurgery is necessary to identify the underlying cause and provide urgent treatment.
Management of aneurysmal SAH involves supportive care, such as bed rest, analgesia, and venous thromboembolism prophylaxis. Vasospasm is prevented with oral nimodipine, and intracranial aneurysms require prompt intervention to prevent rebleeding. Most aneurysms are treated with a coil by interventional neuroradiologists, but some require a craniotomy and clipping by a neurosurgeon. Complications of aneurysmal SAH include re-bleeding, hydrocephalus, vasospasm, and hyponatraemia. Predictive factors for SAH include conscious level on admission, age, and amount of blood visible on CT head.
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This question is part of the following fields:
- Surgery
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Question 5
Correct
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A 75-year-old woman undergoes a left hemicolectomy for colon cancer. The pathology report reveals that the tumour has invaded the muscle layer surrounding the colon but there is no lymph node involvement or distant metastasis on the CT scan of the abdomen and pelvis. What is the Dukes stage of the tumour in this patient?
Your Answer: B
Explanation:The tumour in this patient is classified as Duke Stage B, as it has invaded the local tissue outside of the mucosa but does not involve any lymph nodes, which would make it Duke Stage C. Duke Stage D would involve distant metastases. Staging is crucial in determining prognosis and further management.
While Dukes staging is still widely used, TNM classification is gradually replacing it for colorectal tumours. Tumours that are still within the mucosal wall are classified as T1 or T2, while those that have spread outside the mucosal wall are classified as T3 or T4. Lymph node involvement is classified as N0 (no involvement), N1 (up to 3 regional lymph nodes), or N2 (4 or more regional lymph nodes). Metastasis is classified as either M0 (no metastasis) or M1 (metastasis present).
Duke Stage B can be classified as either T3N0M0 or T4N0M0.
Dukes’ Classification: Stages of Colorectal Cancer
Dukes’ classification is a system used to describe the extent of spread of colorectal cancer. It is divided into four stages, each with a different level of severity and prognosis. Stage A refers to a tumour that is confined to the mucosa, with a 95% 5-year survival rate. Stage B describes a tumour that has invaded the bowel wall, with an 80% 5-year survival rate. Stage C indicates the presence of lymph node metastases, with a 65% 5-year survival rate. Finally, Stage D refers to distant metastases, with a 5% 5-year survival rate (although this increases to 20% if the metastases are resectable).
Overall, Dukes’ classification is an important tool for doctors to use when determining the best course of treatment for patients with colorectal cancer. By understanding the stage of the cancer, doctors can make more informed decisions about surgery, chemotherapy, and other treatments. Additionally, patients can use this information to better understand their prognosis and make decisions about their own care.
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This question is part of the following fields:
- Surgery
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Question 6
Correct
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A 50-year-old man comes to the emergency department complaining of high fever and severe pain in the upper abdomen. He appears disheveled and admits to consuming 50 units of alcohol per week. Despite experiencing symptoms for two days, he delayed seeking medical attention due to a fear of hospitals. What is the most appropriate test to order for the most probable diagnosis?
Your Answer: Lipase
Explanation:Serum lipase is more useful than amylase for diagnosing acute pancreatitis in late presentations (>24 hours). This patient’s lipase level is >3 times normal, confirming the diagnosis. Ultrasound can investigate for bile duct stones, but CT scans are not used for diagnosis.
Understanding Acute Pancreatitis
Acute pancreatitis is a condition that is commonly caused by alcohol or gallstones. It occurs when the pancreatic enzymes start to digest the pancreatic tissue, leading to necrosis. The main symptom of acute pancreatitis is severe epigastric pain that may radiate through to the back. Vomiting is also common, and examination may reveal epigastric tenderness, ileus, and low-grade fever. In rare cases, periumbilical discolouration (Cullen’s sign) and flank discolouration (Grey-Turner’s sign) may be present.
To diagnose acute pancreatitis, doctors typically measure the levels of serum amylase and lipase in the blood. While amylase is raised in 75% of patients, it does not correlate with disease severity. Lipase, on the other hand, is more sensitive and specific than amylase and has a longer half-life. Imaging tests, such as ultrasound and contrast-enhanced CT, may also be used to assess the aetiology of the condition.
Scoring systems, such as the Ranson score, Glasgow score, and APACHE II, are used to identify cases of severe pancreatitis that may require intensive care management. Factors that indicate severe pancreatitis include age over 55 years, hypocalcaemia, hyperglycaemia, hypoxia, neutrophilia, and elevated LDH and AST. It is important to note that the actual amylase level is not of prognostic value.
In summary, acute pancreatitis is a condition that can cause severe pain and discomfort. It is typically caused by alcohol or gallstones and can be diagnosed through blood tests and imaging. Scoring systems are used to identify cases of severe pancreatitis that require intensive care management.
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This question is part of the following fields:
- Surgery
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Question 7
Correct
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A 24-year-old male victim of an acid attack has been brought to the resus department. He has sustained burns on approximately 25% of his body surface area and weighs 60kg. The medical team needs to determine the amount of fluid resuscitation required for the next 24 hours using the Parkland formula based on his weight and the extent of burns. What is the volume of fluid resuscitation that should be administered to this patient over the next 24 hours?
Your Answer: 6000mls
Explanation:Fluid Resuscitation for Burns
Fluid resuscitation is necessary for patients with burns that cover more than 15% of their total body area (10% for children). The primary goal of resuscitation is to prevent the burn from deepening. Most fluid is lost within the first 24 hours after injury, and during the first 8-12 hours, fluid shifts from the intravascular to the interstitial fluid compartments, which can compromise circulatory volume. However, fluid resuscitation causes more fluid to enter the interstitial compartment, especially colloid, which should be avoided in the first 8-24 hours. Protein loss also occurs.
The Parkland formula is used to calculate the total fluid requirement in 24 hours, which is given as 4 ml x (total burn surface area (%)) x (body weight (kg)). Fifty percent of the total fluid requirement is given in the first 8 hours, and the remaining 50% is given in the next 16 hours. The resuscitation endpoint is a urine output of 0.5-1.0 ml/kg/hour in adults, and the rate of fluid is increased to achieve this.
It is important to note that the starting point of resuscitation is the time of injury, and fluids already given should be deducted. After 24 hours, colloid infusion is begun at a rate of 0.5 ml x (total burn surface area (%)) x (body weight (kg)), and maintenance crystalloid (usually dextrose-saline) is continued at a rate of 1.5 ml x (burn area) x (body weight). Colloids used include albumin and FFP, and antioxidants such as vitamin C can be used to minimize oxidant-mediated contributions to the inflammatory cascade in burns. High tension electrical injuries and inhalation injuries require more fluid, and monitoring of packed cell volume, plasma sodium, base excess, and lactate is essential.
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This question is part of the following fields:
- Surgery
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Question 8
Incorrect
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Mrs. Smith has recently been diagnosed with bowel cancer. Which marker would be most effective in monitoring the tumor's progression and response to future treatment?
Your Answer: Ca-125
Correct Answer: CEA
Explanation:Colon cancer treatment response is monitored using CEA.
Although CT scans can reveal malignancy progression, they are not suitable for routine monitoring due to their expense and radiation exposure.
Ovarian cancer is detected using Ca-125 as a tumour marker.
Hepatocellular carcinoma is detected using AFP as a tumour marker.Colorectal cancer is typically diagnosed through CT scans and colonoscopies or CT colonography. Patients with tumors below the peritoneal reflection should also undergo MRI to evaluate their mesorectum. Once staging is complete, a treatment plan is formulated by a dedicated colorectal MDT meeting.
For colon cancer, surgery is the primary treatment option, with resectional surgery being the only cure. The procedure is tailored to the patient and tumor location, with lymphatic chains being resected based on arterial supply. Anastomosis is the preferred method of restoring continuity, but in some cases, an end stoma may be necessary. Chemotherapy is often offered to patients with risk factors for disease recurrence.
Rectal cancer management differs from colon cancer due to the rectum’s anatomical location. Tumors can be surgically resected with either an anterior resection or an abdominoperineal excision of rectum (APER). A meticulous dissection of the mesorectal fat and lymph nodes is integral to the procedure. Neoadjuvant radiotherapy is often offered to patients prior to resectional surgery, and those with obstructing rectal cancer should have a defunctioning loop colostomy.
Segmental resections based on blood supply and lymphatic drainage are the primary operations for cancer. The type of resection and anastomosis depend on the site of cancer. In emergency situations where the bowel has perforated, an end colostomy is often safer. Left-sided resections are more risky, but ileocolic anastomoses are relatively safe even in the emergency setting and do not need to be defunctioned.
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This question is part of the following fields:
- Surgery
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Question 9
Correct
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A 45-year-old patient presents to their GP with a 3-month history of worsening dyspepsia, epigastric pain, and drenching night sweats on a background of recurrent gastric ulcers. The GP urgently refers the patient for investigation. Following a gastroscopy with biopsies taken, a low grade gastric MALT lymphoma is diagnosed, and the presence of H. pylori was also noted on the biopsy report. The patient has no significant past medical history. What treatment plan is the doctor likely to recommend?
Your Answer: Omeprazole, amoxicillin and clarithromycin
Explanation:The recommended treatment for gastric MALT lymphoma associated with H. pylori infection is a combination of omeprazole, amoxicillin, and clarithromycin. This is because the majority of cases are linked to H. pylori, as suggested by the patient’s history of gastric ulcers. Low-grade cases can be treated with H. pylori eradication alone, but high-grade or atypical cases may require chemotherapy and/or radiotherapy. The answer choice of lansoprazole, clarithromycin, and doxycycline is incorrect, as doxycycline is not used in H. pylori eradication. Active monitoring may be an option in some cases, but when a clear cause like H. pylori is identified, treatment is recommended. Partial gastrectomy is not a standard treatment for gastric MALT lymphoma.
Gastric MALT Lymphoma: A Brief Overview
Gastric MALT lymphoma is a type of lymphoma that is commonly associated with H. pylori infection, which is present in 95% of cases. The good news is that this type of lymphoma has a good prognosis, especially if it is low grade. In fact, about 80% of patients with low-grade gastric MALT lymphoma respond well to H. pylori eradication.
One potential feature of gastric MALT lymphoma is the presence of paraproteinaemia, which is an abnormal protein in the blood. However, this is not always present and may not be a reliable indicator of the disease. Overall, gastric MALT lymphoma is a treatable form of lymphoma with a high likelihood of successful treatment.
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This question is part of the following fields:
- Surgery
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Question 10
Incorrect
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A 65-year-old patient has sustained a traumatic burn injury and requires emergency surgery. The patient's electrolyte levels are as follows:
Na+ 131 mmol/l
K+ 5.9 mmol/l
Urea 8.1 mmol/l
Creatinine 78 µmol/l
The patient is being prepared for anesthesia. Which of the following neuromuscular blockers should be avoided in this case?Your Answer: Rocuronium
Correct Answer: Suxamethonium (succinylcholine)
Explanation:Suxamethonium, also known as succinylcholine, has the potential to induce hyperkalemia. This risk is particularly high in patients with burns or trauma, and as a result, depolarizing neuromuscular blockers like suxamethonium are not recommended. On the other hand, non-depolarizing neuromuscular blockers do not pose a risk of hyperkalemia.
Understanding Neuromuscular Blocking Drugs
Neuromuscular blocking drugs are commonly used in surgical procedures as an adjunct to anaesthetic agents. These drugs are responsible for inducing muscle paralysis, which is a necessary prerequisite for mechanical ventilation. There are two types of neuromuscular blocking drugs: depolarizing and non-depolarizing.
Depolarizing neuromuscular blocking drugs bind to nicotinic acetylcholine receptors, resulting in persistent depolarization of the motor end plate. On the other hand, non-depolarizing neuromuscular blocking drugs act as competitive antagonists of nicotinic acetylcholine receptors. Examples of depolarizing neuromuscular blocking drugs include succinylcholine (also known as suxamethonium), while examples of non-depolarizing neuromuscular blocking drugs include tubcurarine, atracurium, vecuronium, and pancuronium.
While these drugs are effective in inducing muscle paralysis, they also come with potential adverse effects. Depolarizing neuromuscular blocking drugs may cause malignant hyperthermia and transient hyperkalaemia, while non-depolarizing neuromuscular blocking drugs may cause hypotension. However, these adverse effects can be reversed using acetylcholinesterase inhibitors such as neostigmine.
It is important to note that suxamethonium is contraindicated for patients with penetrating eye injuries or acute narrow angle glaucoma, as it increases intra-ocular pressure. Additionally, suxamethonium is the muscle relaxant of choice for rapid sequence induction for intubation and may cause fasciculations. Understanding the mechanism of action and potential adverse effects of neuromuscular blocking drugs is crucial in ensuring their safe and effective use in surgical procedures.
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This question is part of the following fields:
- Surgery
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