A 20-year-old man had a malignant hyperthermia crisis during appendicectomy that was treated with dantrolene; his end-tidal CO2, temperature and heart rate are now normal. He is moved to the ICU, where dantrolene is continued and he is watched closely for at least 24 hours. What is the main reason for this?

The crisis can recur within the first day

Dantrolene treats the hyperkalaemia directly

Dantrolene must continue until CK is normal

Stopping dantrolene suddenly causes seizures

Anaesthetic drugs, CPR and ICU care

18 NEET-PG practice questions on Anaesthetic drugs, CPR and ICU care, part of Anaesthesia. The first 18 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 20-year-old man had a malignant hyperthermia crisis during appendicectomy that was treated with dantrolene; his end-tidal CO2, temperature and heart rate are now normal. He is moved to the ICU, where dantrolene is continued and he is watched closely for at least 24 hours. What is the main reason for this?
1. ADantrolene treats the hyperkalaemia directly
2. BDantrolene must continue until CK is normal
3. CStopping dantrolene suddenly causes seizures
4. DThe crisis can recur within the first day
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Answer: D · The crisis can recur within the first day
After a treated crisis, malignant hyperthermia can recur (recrudescence) in a sizeable minority of patients, usually within the first 24 hours, so dantrolene is continued and the patient is monitored in a high-dependency setting. Potassium, CK, myoglobinuria, kidney function and clotting are checked, because rhabdomyolysis can cause hyperkalaemia, acute kidney injury and DIC. The patient and family must be told of the diagnosis, given an anaesthetic alert and referred for susceptibility testing, as the trait is autosomal dominant.
- A: Hyperkalaemia is treated with calcium, insulin-glucose and hyperventilation; dantrolene acts on the cause.
- B: CK often peaks a day or more later; dantrolene is not titrated to CK.
- C: Dantrolene is not known to cause withdrawal seizures when stopped.
Question 2 · Medium
A 32-year-old man with a fractured femur after a road accident is taken for nailing under general anaesthesia. Chest X-ray in casualty showed a small left pneumothorax that has not been drained, and he is breathing comfortably. Which anaesthetic gas should be avoided?
1. ANitrous oxide
2. BSevoflurane
3. CDesflurane
4. DIsoflurane
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Answer: A · Nitrous oxide
Nitrous oxide is about 30 times more soluble in blood than nitrogen, so it enters air-filled spaces much faster than nitrogen can leave them. A compliant space such as a pneumothorax or obstructed bowel expands, and a closed rigid space such as the middle ear rises in pressure. A small pneumothorax can thus become a tension pneumothorax; positive pressure ventilation adds to the risk, so a chest drain is often placed first. Other contraindications include air embolism, pneumocephalus and intraocular gas.
- B: Sevoflurane is used at low concentration and does not expand gas spaces significantly.
- C: Desflurane does not expand closed gas spaces; its drawback is airway irritation.
- D: Isoflurane does not expand closed gas spaces.
Question 3 · Medium
A 68-year-old woman admitted with pneumonia is hypoxic, and the ward resident reviews her oxygen devices. Consider four statements: 1. A Venturi mask delivers a fixed FiO2 even if her breathing pattern changes. 2. A nasal cannula at 6 L/min gives an FiO2 of about 0.9. 3. The reservoir bag of a non-rebreathing mask should not collapse during inspiration. 4. High-flow nasal oxygen provides a small amount of positive airway pressure. Which statements are correct?
1. A1, 3 and 4 only
2. B1, 2 and 3 only
3. C1 and 3 only
4. D1, 2, 3 and 4
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Answer: A · 1, 3 and 4 only
Statements 1, 3 and 4 are correct. A Venturi mask entrains room air in a fixed ratio and delivers a total flow above the patient's inspiratory demand, so the FiO2 stays fixed. A non-rebreathing mask gives a high FiO2 only if the flow keeps the reservoir bag from collapsing, and heated, humidified high-flow nasal oxygen washes out dead space and gives a little positive pressure. Statement 2 is wrong: nasal cannulae add roughly 4% per litre, giving an FiO2 of only about 0.4 at 6 L/min.
- B: Includes statement 2; nasal cannulae give an FiO2 of only about 0.4 at 6 L/min.
- C: Omits statement 4; high-flow nasal oxygen does give some positive pressure.
- D: Includes statement 2, which overstates nasal cannula oxygen more than twofold.
Question 4 · Medium
A 45-year-old man has a cardiac arrest in the surgical ward. The team leader reminds the team about high-quality CPR: 1. Compress at a rate of 100-120 per minute. 2. Compress the adult chest at least 5 cm but not more than 6 cm. 3. Once a tracheal tube is in place, pause after every 30 compressions for 2 breaths. 4. Lean on the chest between compressions to keep the hands in position. Which of these are correct?
1. A1, 2 and 4 only
2. B1, 2 and 3 only
3. C1 and 2 only
4. D1, 2, 3 and 4
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Answer: C · 1 and 2 only
Statements 1 and 2 are correct: adult compressions are given at 100-120 per minute to a depth of 5-6 cm. Statement 3 is wrong because once an advanced airway is in place compressions continue without pauses and one breath is given every 6 seconds. Statement 4 is wrong because leaning prevents full chest recoil, which reduces venous return and coronary perfusion. Interruptions are kept as short as possible, and compressors change about every 2 minutes to avoid fatigue.
- A: Includes statement 4; leaning prevents full recoil and reduces venous return.
- B: Includes statement 3; with an advanced airway, compressions are continuous with a breath every 6 seconds.
- D: Includes statements 3 and 4, both incorrect.
Question 5 · Easy
A 22-year-old man with life-threatening acute asthma is to be intubated in the ICU after failing maximal bronchodilator therapy. Which induction agent is preferred because it relaxes bronchial smooth muscle?
1. AKetamine
2. BMorphine
3. CThiopentone sodium
4. DEtomidate
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Answer: A · Ketamine
Ketamine, an NMDA receptor antagonist, releases catecholamines and relaxes bronchial smooth muscle, so it is the preferred induction agent in severe bronchospasm. It also tends to keep the blood pressure up. It increases secretions, so an antisialagogue may be given, and emergence reactions are reduced with a benzodiazepine. Ventilation after intubation uses a long expiratory time to avoid gas trapping.
- B: Morphine releases histamine and is not an induction agent for this purpose.
- C: Thiopentone can provoke bronchospasm at light planes and has no bronchodilator effect.
- D: Etomidate keeps the blood pressure stable but does not dilate the bronchi.
Question 6 · Medium
A 55-year-old man collapses in the coronary care unit, and the monitor shows ventricular fibrillation. High-quality CPR is started, he receives three shocks with 2-minute cycles of CPR in between, and 1 mg IV adrenaline was given after the second shock. The rhythm is still VF after the third shock. Which drug should be given now?
1. AAmiodarone 300 mg IV bolus
2. BAtropine 1 mg IV
3. CA repeat 1 mg IV adrenaline
4. DCalcium gluconate 10 mL of 10%
Answer and explanation in LearnFree account
Question 7 · Hard
A 56-year-old man on maintenance haemodialysis has missed two sessions and is brought to casualty weak. An ECG shows tall peaked T waves and a wide QRS, and while it is being recorded he becomes unresponsive and pulseless with a slow broad-complex rhythm on the monitor. CPR is started and 1 mg adrenaline given. Point-of-care potassium is 8.4 mmol/L. Which drug is most urgently needed?
1. AIntravenous calcium chloride
2. BIntravenous amiodarone 300 mg
3. CIntravenous atropine 3 mg
4. DOral sodium polystyrene sulphonate
Answer and explanation in LearnFree account
Question 8 · Medium
During CPR for a PEA arrest in a 62-year-old woman on the ward, the end-tidal CO2 through her tracheal tube has stayed around 15 mmHg for 8 minutes. During compressions it suddenly rises to 42 mmHg and stays there. What does this most likely indicate?
1. ADisplacement of the tube into the oesophagus
2. BRescuer fatigue with poorer compressions
3. CBronchospasm caused by the tube
4. DReturn of spontaneous circulation
Answer and explanation in LearnFree account
Question 9 · Medium
At a railway station in Pune, a 50-year-old man suddenly collapses. A medical intern finds him unresponsive; his chest does not move except for an occasional deep, noisy gasp, and she cannot feel a definite pulse within 10 seconds. A bystander has already called for help and gone to fetch the station's AED. What should she do next?
1. AWait for the AED before starting CPR
2. BGive two rescue breaths and recheck
3. CStart chest compressions at once
4. DPlace him in the recovery position
Answer and explanation in LearnFree account
Question 10 · Medium
A frightened 4-year-old girl with no IV access is to have dental extractions under general anaesthesia. The anaesthetist plans inhalational induction through a face mask. Which agent is best suited?
1. ASevoflurane
2. BIsoflurane
3. CDesflurane
4. DNitrous oxide alone
Answer and explanation in LearnFree account
Question 11 · Medium
A 58-year-old man in the ICU is on non-invasive ventilation for an exacerbation of COPD. He is agitated and keeps pulling off his mask. The intensivist wants a sedative that keeps him easily rousable and causes little respiratory depression. Which drug best fits?
1. AMidazolam infusion
2. BMorphine infusion
3. CPropofol infusion
4. DDexmedetomidine
Answer and explanation in LearnFree account
Question 12 · Hard
A 24-year-old man with severe traumatic brain injury has been sedated in the neuro-ICU with a high-dose propofol infusion (about 6 mg/kg/h) for 4 days to control intracranial pressure. He now has a metabolic acidosis with lactate 7 mmol/L, potassium 6.1 mmol/L, CK 18,000 U/L, rising triglycerides, dark urine and a new right bundle branch block with hypotension. What is the most likely diagnosis?
1. ASeptic shock with rhabdomyolysis
2. BMalignant hyperthermia
3. CPropofol infusion syndrome
4. DNeuroleptic malignant syndrome
Answer and explanation in LearnFree account
Question 13 · Easy
A 26-year-old woman with acute intermittent porphyria, who has had two previous attacks of abdominal pain, confusion and dark urine, is listed for emergency appendicectomy. Which anaesthetic drug must be avoided?
1. APropofol
2. BFentanyl
3. CThiopentone sodium
4. DAtracurium
Answer and explanation in LearnFree account
Question 14 · Easy
A 14-year-old girl is under general anaesthesia with sevoflurane for an elective tibial osteotomy. Forty minutes into the operation the anaesthetist suspects early malignant hyperthermia. Which monitored change is usually the earliest sign?
1. ADark-coloured urine in the bag
2. BFall in SpO2 on pulse oximetry
3. CRise in core body temperature
4. DUnexplained rise in end-tidal CO2
Answer and explanation in LearnFree account
Question 15 · Medium
A 30-year-old woman who vomited severely after previous anaesthetics is listed for day-care diagnostic laparoscopy. The anaesthetist plans total intravenous anaesthesia with propofol. Consider four statements about propofol: 1. It has an antiemetic effect. 2. It commonly causes pain on injection into small veins. 3. Its lipid emulsion supports bacterial growth, so it must be handled aseptically and used promptly. 4. It raises blood pressure through sympathetic stimulation. Which statements are correct?
1. A1, 2 and 3 only
2. B1 and 2 only
3. C2, 3 and 4 only
4. D1, 2, 3 and 4
Answer and explanation in LearnFree account
Question 16 · Hard
A 40-year-old woman with influenza A (H1N1) pneumonia has been ventilated in the ICU for 18 hours with a tidal volume of 6 mL/kg predicted body weight, plateau pressure 28 cmH2O and PEEP 14 cmH2O. Chest X-ray shows bilateral opacities and echocardiography is normal. On FiO2 0.9 her PaO2 is 72 mmHg. What is the next best step?
1. AProne positioning for at least 12 hours a day
2. BIncrease the tidal volume to 10 mL/kg
3. CHigh-frequency oscillatory ventilation
4. DRoutine inhaled nitric oxide
Answer and explanation in LearnFree account
Question 17 · Medium
A 60-year-old man with septic shock from cholangitis was intubated in casualty with a single dose of an induction agent chosen because it kept his blood pressure stable. Over the next day his hypotension responds poorly to noradrenaline and his serum cortisol is low. Which enzyme does this drug inhibit?
1. A17-alpha-hydroxylase
2. BAromatase
3. C21-hydroxylase
4. D11-beta-hydroxylase
Answer and explanation in LearnFree account
Question 18 · Medium
A 59-year-old man has return of spontaneous circulation after 12 minutes of CPR for VF arrest in the emergency department. He is intubated and ventilated on FiO2 1.0; SpO2 is 100%, PaO2 410 mmHg, PaCO2 40 mmHg and BP 112/70 mmHg. What should be done with his inspired oxygen?
1. AReduce the FiO2 to keep SpO2 92-98%
2. BSwitch to hyperbaric oxygen therapy
3. CReduce the FiO2 to keep SpO2 85-88%
4. DKeep FiO2 at 1.0 for the first 24 hours
Answer and explanation in LearnFree account

Anaesthetic drugs, CPR and ICU care

A 32-year-old man with a fractured femur after a road accident is taken for nailing under general anaesthesia. Chest X-ray in casualty showed a small left pneumothorax that has not been drained, and he is breathing comfortably. Which anaesthetic gas should be avoided?

A 22-year-old man with life-threatening acute asthma is to be intubated in the ICU after failing maximal bronchodilator therapy. Which induction agent is preferred because it relaxes bronchial smooth muscle?

During CPR for a PEA arrest in a 62-year-old woman on the ward, the end-tidal CO2 through her tracheal tube has stayed around 15 mmHg for 8 minutes. During compressions it suddenly rises to 42 mmHg and stays there. What does this most likely indicate?

A frightened 4-year-old girl with no IV access is to have dental extractions under general anaesthesia. The anaesthetist plans inhalational induction through a face mask. Which agent is best suited?

A 58-year-old man in the ICU is on non-invasive ventilation for an exacerbation of COPD. He is agitated and keeps pulling off his mask. The intensivist wants a sedative that keeps him easily rousable and causes little respiratory depression. Which drug best fits?

A 26-year-old woman with acute intermittent porphyria, who has had two previous attacks of abdominal pain, confusion and dark urine, is listed for emergency appendicectomy. Which anaesthetic drug must be avoided?

A 14-year-old girl is under general anaesthesia with sevoflurane for an elective tibial osteotomy. Forty minutes into the operation the anaesthetist suspects early malignant hyperthermia. Which monitored change is usually the earliest sign?

A 59-year-old man has return of spontaneous circulation after 12 minutes of CPR for VF arrest in the emergency department. He is intubated and ventilated on FiO2 1.0; SpO2 is 100%, PaO2 410 mmHg, PaCO2 40 mmHg and BP 112/70 mmHg. What should be done with his inspired oxygen?