بنك أسئلة العناية المركزة

اقرأ أسئلة عيّنة بنك أسئلة العناية المركزة

1. 1.Guillain-Barré syndrome (GBS):

   • أ.Affects more females than males.
   • ب.Is a disease of the middle-aged.
   • ج.When secondary to a respiratory illness, the majority of cases present within a month.إجابة صحيحة
   • د.The presence of cranial nerve signs effectively rules out the diagnosis

   لماذا: When GBS follows an antecedent infection (often respiratory or gastrointestinal), the demyelinating attack typically begins within 1-4 weeks, so the majority of post-infectious cases present within a month. GBS affects males slightly more than females, can occur at any age, and cranial nerve involvement (e.g. facial weakness, the Miller-Fisher variant) is well recognised, so it does not rule out the diagnosis.

2. 2.In the trauma patient with massive haemorrhage, the following statements are correct:

   • أ.An initial target systolic blood pressure of 80-90mmHg is recommended for the patient without brain injuryإجابة صحيحة
   • ب.Desmopressin at a dose of 0.3μg/kg is recommended in the bleeding patient taking platelet-inhibiting drugs.
   • ج.Recombinant factor VIIa (rFVIIa) can be considered as a rescue measure provided the platelet count is greater than 30 x 10 9 /L.
   • د.Pre-injury warfarin use doubles the odds of death for trauma patients with blunt head injury.

   لماذا: In uncontrolled haemorrhage without traumatic brain injury, permissive hypotension targeting a systolic of about 80-90 mmHg limits clot disruption and dilutional coagulopathy until bleeding is controlled. This 'hypotensive resuscitation' strategy is endorsed by European trauma guidelines; the higher MAP targets needed for TBI do not apply here.

3. 3.The following drugs undergo non-organ metabolism:

   • أ.Esmololإجابة صحيحة
   • ب.Atracurium
   • ج.Inhaled nitric oxide.
   • د.Propofol

   لماذا: Esmolol is hydrolysed by red blood cell esterases independent of hepatic or renal function, giving it an ultra-short half-life. Atracurium undergoes Hofmann elimination/ester hydrolysis (organ-independent) and inhaled nitric oxide is rapidly bound by haemoglobin, so several options are non-organ dependent; however among the choices esmolol is the keyed example of plasma-esterase metabolism. Propofol, by contrast, is predominantly hepatically metabolised.

4. 4.Which of the following features of an asthma attack are classified as 'lifethreatening' in the 2011 BTS asthma guideline?

   • أ.Inability to complete sentences in one breath.
   • ب.PaO 2 of >8kPa.
   • ج.Silent chest.إجابة صحيحة
   • د.PaCO 2 >6kPa.

   لماذا: A silent chest indicates airflow so reduced that wheeze can no longer be generated, a recognised life-threatening feature in the BTS/SIGN asthma guideline. Inability to complete sentences and a normal/rising PaCO2 are markers of acute severe or life-threatening disease, but the silent chest is the classic life-threatening physical sign signalling imminent respiratory arrest.

5. 5.With regard to bleeding and coagulopathy in the critically ill patient:

   • أ.If a platelet transfusion is indicated, 1 unit will raise the count by approximately 20 x 10^9 /L.
   • ب.The principal constituents of cryoprecipitate include Factors VIII, XIII, vWF, fibronectin and fibrinogen.إجابة صحيحة
   • ج.A suggested dose of fresh frozen plasma in the bleeding trauma patient with coagulopathy is 30ml/kg.
   • د.Desmopressin at a dose of 0.3μg/kg is a useful treatment in patients with coagulopathy related to uraemia, cirrhosis and aspirin use.

   لماذا: Cryoprecipitate is the cold-insoluble fraction of plasma and is rich in fibrinogen, Factor VIII, Factor XIII, von Willebrand factor and fibronectin, making it the product of choice for hypofibrinogenaemia. The other statements contain errors (e.g. one adult pool of platelets, not a single unit, raises the count by ~20x10^9/L).

6. 6.Regarding drug-receptor interactions:

   • أ.An antagonist has receptor affinity and intrinsic activity.
   • ب.Increasing the dose of a partial agonist can elicit a maximal effect.
   • ج.β-receptor blockers are reversible antagonists.إجابة صحيحة
   • د.Flumazenil is an inverse agonist.

   لماذا: Beta-blockers compete reversibly with catecholamines at the receptor and their effect can be overcome by increasing agonist concentration, defining them as reversible (competitive) antagonists. An antagonist has affinity but no intrinsic activity; a partial agonist cannot produce a maximal response however high the dose; and flumazenil is a competitive antagonist, not an inverse agonist.

7. 7.Regarding the hepatorenal syndrome (HRS):

   • أ.It is commonly over-diagnosed in patients with cirrhotic liver diseaseإجابة صحيحة
   • ب.HRS Type 1 has the poorest outcome.
   • ج.Kidneys from patients with HRS are suitable for transplantation.
   • د.The condition is associated with splanchnic vasodilatation.

   لماذا: HRS is a diagnosis of exclusion in cirrhosis and is frequently over-diagnosed because other causes of AKI (hypovolaemia, ATN, sepsis, nephrotoxins) must first be ruled out. It is driven by splanchnic vasodilatation with secondary renal vasoconstriction; Type 1 carries the worst prognosis and HRS kidneys can recover, so they are suitable for transplantation.

8. 8.With regard to a patient with a neuromuscular disorder on the critical care unit:

   • أ.Potassium-sparing diuretics should be avoided in patients with hypokalaemic periodic paralysis.
   • ب.Suxamethonium use should be avoided in patients with myasthenia gravis.
   • ج.Patients with motor neurone disease typically require double the standard dose of suxamethonium to provide optimum intubating conditions.
   • د.Local anaesthesia can exacerbate symptoms of multiple sclerosis.إجابة صحيحة

   لماذا: Local (regional) anaesthesia and the associated stress/temperature changes can exacerbate multiple sclerosis symptoms, and amide local anaesthetics should be used cautiously. Suxamethonium is actually relatively resistant in myasthenia (patients may need more, not avoidance per se), but is dangerous in MND/denervation due to hyperkalaemia; potassium-sparing diuretics are useful, not avoided, in hypokalaemic periodic paralysis.

9. 9.Regarding parenteral nutrition in the critically ill patient:

   • أ.A patient with enteral feeds running at 40ml/hr with 4-hourly aspirates of >200ml is deemed to be failing enteral nutrition.
   • ب.Daily caloric intake should be 100-130% of the patient's calculated daily energy expenditure.
   • ج.Parenteral nutrition can be administered peripherally.إجابة صحيحة
   • د.Approximately 1g/kg/day of nitrogen is required.

   لماذا: Parenteral nutrition can be given through a peripheral vein, but only lower-osmolarity formulations and for short periods because of the high risk of thrombophlebitis; concentrated PN requires central access. Daily calories should approximate, not exceed (100-130% is excessive), measured expenditure, and nitrogen requirement is roughly 0.15-0.2 g/kg/day, not 1 g/kg/day.

10. 10.A 67-year-old male has a diagnosis of myasthenia gravis (MG). Which of the following medications should be avoided to reduce the risk of exacerbation?

    • أ.Gentamicinإجابة صحيحة
    • ب.Paracetamol
    • ج.Trimethoprim
    • د.Ciprofloxacin

    لماذا: Aminoglycosides such as gentamicin impair neuromuscular transmission by reducing presynaptic acetylcholine release and blocking postsynaptic receptors, which can precipitate a myasthenic crisis. Paracetamol is safe; trimethoprim and ciprofloxacin are used with caution but gentamicin is the classic drug to avoid in myasthenia gravis. [REVIEW: keyed answer (gentamicin) is correct, but fluoroquinolones such as ciprofloxacin are also recognised precipitants and should be used cautiously.]