MRCS Part A Principles of Surgery-in-General Flashcards

24 sample cards from the Principles of Surgery-in-General deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. What does a suture's USP gauge indicate (e.g. 3-0 vs 5-0)?

   It denotes thread diameter: the more zeros, the thinner the suture. So $5\text{-}0$ is thinner than $3\text{-}0$. Thinner sutures are used for finer, less load-bearing tissue (e.g. face, vessels).

2. Define minimally invasive (laparoscopic) surgery and list three physiological effects of the pneumoperitoneum.

   Surgery through small ports using a camera and long instruments. $\mathrm{CO_2}$ pneumoperitoneum causes: raised intra-abdominal pressure (reduced venous return, splinted diaphragm), hypercarbia/absorption acidosis, and reduced renal/splanchnic perfusion.

3. List advantages of minimally invasive surgery over open surgery.

   Less postoperative pain, smaller scars, reduced wound infection/hernia, shorter hospital stay, faster return to normal activity, and less blood loss — at the cost of longer operating time, cost and a learning curve.

4. Why is $\mathrm{CO_2}$ chosen as the insufflation gas for laparoscopy?

   It is non-combustible (safe with diathermy), highly soluble/rapidly absorbed and excreted (low risk of gas embolism), colourless, and inexpensive.

5. Name three advanced/robotic surgical technologies and one benefit of robotic surgery.

   Robotic platforms (e.g. da Vinci), image-guided/navigation surgery, and intraoperative fluorescence (indocyanine green). Robotic benefit: wristed instruments with $7$ degrees of freedom, tremor filtration and 3D magnified vision improving precision in confined spaces.

6. Define the systemic inflammatory response syndrome (SIRS) criteria.

   Two or more of: temperature $>38\,^{\circ}\mathrm{C}$ or $<36\,^{\circ}\mathrm{C}$; heart rate $>90/min$; respiratory rate $>20/min$ or $\mathrm{PaCO_2}<4.3\ kPa$; WCC $>12$ or $<4 \times 10^{9}/L$.

7. What is the current (Sepsis-3) definition of sepsis and septic shock?

   Sepsis: life-threatening organ dysfunction (rise in SOFA score $\geq 2$) caused by a dysregulated host response to infection. Septic shock: sepsis with persistent hypotension needing vasopressors to keep MAP $\geq 65\ mmHg$ and lactate $>2\ mmol/L$ despite fluids.

8. List the components of the 'Sepsis Six' bundle to be delivered within 1 hour.

   Give: oxygen, IV fluids, IV antibiotics. Take: blood cultures, lactate, and monitor urine output. (3 in, 3 out.)

9. Give the formula for Mean Arterial Pressure (MAP) and its critical organ-perfusion threshold.

   $$MAP = DBP + \frac{1}{3}(SBP - DBP)$$ A MAP of at least $65\ mmHg$ is generally required to maintain vital organ perfusion.

10. Classify haemorrhagic shock by the ATLS four classes (blood loss and signs).

    Class I: $<15\%$ (up to $750\ mL$), normal signs. Class II: $15\text{–}30\%$, tachycardia, narrowed pulse pressure. Class III: $30\text{–}40\%$, hypotension, confusion. Class IV: $>40\%$, marked hypotension, negligible urine output — immediately life-threatening.

11. Describe the classification of postoperative pyrexia by timing ('the 5 Ws').

    Wind (atelectasis/pneumonia, days $1$–$2$), Water (UTI, days $3$–$5$), Wound (infection, days $5$–$7$), Walking (DVT/PE, days $5$+), and Wonder drugs / lines (drug reaction, IV-line sepsis).

12. What are the components of Virchow's triad predisposing to venous thromboembolism?

    Stasis (immobility), endothelial injury (surgery/trauma), and hypercoagulability (malignancy, pregnancy, thrombophilia).

13. List methods of VTE prophylaxis in surgical patients (mechanical and pharmacological).

    Mechanical: early mobilisation, graduated compression stockings, intermittent pneumatic compression. Pharmacological: low-molecular-weight heparin, unfractionated heparin, or DOACs — balanced against bleeding risk.

14. Define wound dehiscence and give its typical presentation.

    Partial or complete separation of the layers of a surgical wound. Classically presents around day $5$–$8$ with a serosanguinous ('pink') discharge; 'burst abdomen' with bowel evisceration is a surgical emergency.

15. Distinguish an anastomotic leak's typical onset and key clinical signs.

    Usually presents around days $5$–$7$ with fever, tachycardia, prolonged ileus, abdominal pain/peritonism, raised inflammatory markers, and sometimes faeculent drain output. Requires urgent imaging (CT with contrast) and intervention.

16. What is the Clavien-Dindo classification used for, and outline its grades?

    It grades the severity of surgical complications by the treatment required. Grade I: any deviation, no treatment; II: pharmacological treatment/transfusion; III: surgical/endoscopic/radiological intervention (IIIa no GA, IIIb with GA); IV: life-threatening/organ failure (ICU); V: death.

17. Outline the metabolic (Cuthbertson/Moore) phases of the stress response to surgery.

    Ebb phase (first $\sim 24$ h): hypometabolism, hypovolaemia, catecholamine surge. Flow phase: catabolism, hypermetabolism, negative nitrogen balance, insulin resistance. Anabolic recovery phase: restoration of protein/fat stores.

18. Define daily maintenance fluid and electrolyte requirements for an adult (NICE).

    Water $\approx 25\text{–}30\ mL/kg/day$; sodium, potassium and chloride $\approx 1\ mmol/kg/day$ each; glucose $\approx 50\text{–}100\ g/day$ to limit ketosis.

19. State the daily energy and protein requirements to consider in surgical nutritional support.

    Approximately $25\text{–}30\ kcal/kg/day$ energy and $\approx 1.0\text{–}1.5\ g/kg/day$ protein (nitrogen $\approx 0.15\text{–}0.25\ g/kg/day$), guided by catabolic state.

20. What is refeeding syndrome and its biochemical hallmarks?

    A dangerous fluid/electrolyte shift on reintroducing nutrition to a starved patient, driven by insulin surge. Hallmarks: hypophosphataemia (key), hypokalaemia, hypomagnesaemia, and thiamine deficiency — risking arrhythmia and cardiac failure.

21. Define the four principles (pillars) of medical ethics relevant to surgical decision-making.

    Autonomy (respect patient self-determination), Beneficence (act in the patient's best interest), Non-maleficence ('first do no harm'), and Justice (fair distribution of resources and equal treatment).

22. What is a DNACPR decision and does it require patient consent?

    A Do Not Attempt CPR decision recording that cardiopulmonary resuscitation will not be attempted. It is a clinical decision, but there is a legal duty to consult and inform the patient (or, if they lack capacity, those close to them) — established by Tracey (2014).

23. Define the doctrine of double effect in end-of-life surgical/palliative care.

    Providing treatment (e.g. opioids/sedation) with the primary intention of relieving suffering is ethically and legally permissible even if a foreseen but unintended secondary effect is to hasten death — provided the intent is symptom relief, not to kill.

24. What is the QALY and how is it used in resource allocation (e.g. NICE)?

    The Quality-Adjusted Life Year combines length and quality of life ($1$ QALY = one year in perfect health). Cost-effectiveness is judged by cost per QALY; NICE typically uses a threshold around $£20{,}000\text{–}£30{,}000$ per QALY to allocate finite resources justly.

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