A 66-year-old man with moderate COPD has a right interscalene brachial plexus block for arthroscopic shoulder surgery. In recovery he is breathless, with reduced breath sounds at the right base; chest X-ray shows a raised right hemidiaphragm and no pneumothorax. He also has right ptosis and a small right pupil. Which structure has been blocked to cause his breathlessness?

Right recurrent laryngeal nerve

Right cervical sympathetic chain

A 70-year-old man has spinal anaesthesia with hyperbaric bupivacaine for transurethral resection of a bladder tumour. Ten minutes later the sensory block reaches T2. His pulse falls from 78 to 44/min and BP from 140/80 to 86/50 mmHg. Which mechanism best explains the bradycardia?

Block of cardioaccelerator fibres from T1-T4

Direct depression of the SA node by bupivacaine

Reflex response to hypercapnia from weak breathing

Block of the vagus nerve in the brainstem

A 24-year-old woman had a caesarean under spinal anaesthesia 3 days ago. She has a severe fronto-occipital headache that comes on within minutes of sitting up and eases on lying flat, with neck stiffness and nausea. She has no fever and her neurological examination is normal. Two days of fluids, paracetamol and caffeine have not helped, and she cannot care for her baby. What is the most effective treatment?

Strict bed rest for another week

Before starting labour analgesia, a resident gives 3 mL of 1.5% lignocaine with adrenaline 1:200,000 through a newly placed lumbar epidural catheter. Within 45 seconds the mother's heart rate rises from 88 to 120/min, between contractions, and then settles. Five minutes later she has no leg weakness. What should be done next?

Withdraw or re-site the catheter

Use it for continuous spinal analgesia

Give the full epidural dose through it

Inject a further 10 mL as a second test

A 40-year-old man is listed for haemorrhoidectomy. The anaesthetist wants anaesthesia of the perineum only, with little effect on leg power or blood pressure. Hyperbaric bupivacaine is injected at L4-L5 with the patient sitting, and he is kept sitting for several minutes before lying down. Why is the block confined to the sacral segments?

The dense solution settles in the lowest part of the sac

The sacral roots lack a myelin sheath

Bupivacaine binds selectively to sacral roots

CSF flow carries the drug down to the sacrum

Spinal, epidural and local anaesthesia

18 NEET-PG practice questions on Spinal, epidural and local anaesthesia, 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 66-year-old man with moderate COPD has a right interscalene brachial plexus block for arthroscopic shoulder surgery. In recovery he is breathless, with reduced breath sounds at the right base; chest X-ray shows a raised right hemidiaphragm and no pneumothorax. He also has right ptosis and a small right pupil. Which structure has been blocked to cause his breathlessness?
1. ARight recurrent laryngeal nerve
2. BRight phrenic nerve
3. CRight long thoracic nerve
4. DRight cervical sympathetic chain
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Answer: B · Right phrenic nerve
The interscalene block is given at the level of C5-C6, close to the phrenic nerve (C3-C5) lying on scalenus anterior, and it blocks the phrenic nerve in almost every patient, paralysing the diaphragm on that side. Healthy patients tolerate this, but in COPD the loss of half the diaphragm can cause respiratory distress. Spread to the cervical sympathetic chain explains his Horner syndrome, and hoarseness can follow recurrent laryngeal block. Patients with poor lung reserve are offered a lower-volume block or an alternative such as a suprascapular nerve block.
- A: Recurrent laryngeal block causes hoarseness, not a raised hemidiaphragm.
- C: The long thoracic nerve supplies serratus anterior; its loss causes winging, not diaphragm paralysis.
- D: Sympathetic block explains the ptosis and small pupil, not the breathlessness.
Question 2 · Medium
A 70-year-old man has spinal anaesthesia with hyperbaric bupivacaine for transurethral resection of a bladder tumour. Ten minutes later the sensory block reaches T2. His pulse falls from 78 to 44/min and BP from 140/80 to 86/50 mmHg. Which mechanism best explains the bradycardia?
1. ADirect depression of the SA node by bupivacaine
2. BBlock of cardioaccelerator fibres from T1-T4
3. CReflex response to hypercapnia from weak breathing
4. DBlock of the vagus nerve in the brainstem
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Answer: B · Block of cardioaccelerator fibres from T1-T4
The cardiac sympathetic (cardioaccelerator) fibres arise from T1 to T4, so a block reaching this level leaves vagal tone unopposed. Reduced venous return from venodilatation adds to the slowing through reflexes from the stretch receptors of the heart. Treatment is atropine or ephedrine with fluids, and adrenaline if the fall is severe. High blocks in elderly patients need close watching, because sudden asystole can occur.
- A: Spinal doses of bupivacaine give far too low a blood level to depress the SA node.
- C: Hypercapnia raises the heart rate through sympathetic stimulation and is not present here.
- D: Vagal block would cause tachycardia, and the brainstem is not reached by this block.
Question 3 · Medium
A 24-year-old woman had a caesarean under spinal anaesthesia 3 days ago. She has a severe fronto-occipital headache that comes on within minutes of sitting up and eases on lying flat, with neck stiffness and nausea. She has no fever and her neurological examination is normal. Two days of fluids, paracetamol and caffeine have not helped, and she cannot care for her baby. What is the most effective treatment?
1. AOral sumatriptan
2. BStrict bed rest for another week
3. CEpidural blood patch
4. DIntravenous ceftriaxone
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Answer: C · Epidural blood patch
A positional headache within days of a dural puncture is post-dural puncture headache: CSF leaks through the dural hole, intracranial pressure falls and pain-sensitive structures are stretched. Simple measures come first, but severe or persistent headache is best treated with an epidural blood patch, in which about 20 mL of her own blood, drawn aseptically, is injected into the epidural space at or near the puncture level and seals the leak. Red flags such as fever, focal signs or a non-positional headache must be excluded first, because meningitis, subdural haematoma and venous sinus thrombosis can follow delivery.
- A: Triptans are for migraine and have no proven role in this headache.
- B: Bed rest does not shorten or prevent the headache.
- D: There is no fever or other sign of meningitis to justify antibiotics.
Question 4 · Hard
Before starting labour analgesia, a resident gives 3 mL of 1.5% lignocaine with adrenaline 1:200,000 through a newly placed lumbar epidural catheter. Within 45 seconds the mother's heart rate rises from 88 to 120/min, between contractions, and then settles. Five minutes later she has no leg weakness. What should be done next?
1. AUse it for continuous spinal analgesia
2. BWithdraw or re-site the catheter
3. CGive the full epidural dose through it
4. DInject a further 10 mL as a second test
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Answer: B · Withdraw or re-site the catheter
The test dose contains 15 micrograms of adrenaline; if it enters a vein, the heart rate rises sharply within about a minute, so this catheter is probably in an epidural vein. The lack of leg weakness at 5 minutes shows that it is not intrathecal. Giving the full dose would risk local anaesthetic systemic toxicity, so the catheter is withdrawn a little and re-tested, or re-sited. Labour pain itself raises the heart rate, so the test is read between contractions, and it is less reliable in patients on beta-blockers.
- A: There is no motor block, so the catheter is not intrathecal; it is probably in a vein.
- C: A full dose into a vein could cause local anaesthetic systemic toxicity.
- D: A larger 'test' into a vein is itself a toxic dose.
Question 5 · Medium
A 40-year-old man is listed for haemorrhoidectomy. The anaesthetist wants anaesthesia of the perineum only, with little effect on leg power or blood pressure. Hyperbaric bupivacaine is injected at L4-L5 with the patient sitting, and he is kept sitting for several minutes before lying down. Why is the block confined to the sacral segments?
1. AThe sacral roots lack a myelin sheath
2. BBupivacaine binds selectively to sacral roots
3. CCSF flow carries the drug down to the sacrum
4. DThe dense solution settles in the lowest part of the sac
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Answer: D · The dense solution settles in the lowest part of the sac
Hyperbaric bupivacaine contains dextrose and is denser than CSF, so it moves with gravity. With the patient sitting, it pools in the lowest part of the dural sac and blocks the sacral roots (a saddle block), sparing the lumbar and thoracic roots. The small spread gives little sympathetic block, so blood pressure is barely affected. A hypobaric solution would rise instead and is sometimes used for operations in the jack-knife position.
- A: Sacral roots are myelinated like other roots; the selective block is due to gravity.
- B: Bupivacaine has no selective affinity for sacral roots.
- C: There is no downward flow of CSF that carries the drug; gravity acting on the dense solution does it.
Question 6 · Medium
A 3-week-old baby in a NICU had EMLA cream applied thickly over a large area of skin and left under an occlusive dressing for several hours before procedures. He becomes grey-blue; SpO2 reads 86% and does not improve with 100% oxygen, and arterial blood is chocolate-brown with a normal PaO2. Which component is responsible?
1. ALignocaine
2. BPrilocaine
3. CTetracaine
4. DBenzocaine
Answer and explanation in LearnFree account
Question 7 · Easy
A 26-year-old woman is to have an elective caesarean section under spinal anaesthesia at a district hospital. She is anxious because her sister had a severe headache for a week after her own spinal. Which choice of needle most reduces the risk of this headache?
1. AA 22G Quincke cutting needle
2. BAn 18G Tuohy epidural needle
3. CA 23G Quincke, bevel across fibres
4. DA 25G or 27G pencil-point needle
Answer and explanation in LearnFree account
Question 8 · Easy
A 45-year-old man receives spinal anaesthesia for a hernia repair. Within the first minutes his feet feel warm and flushed, before he loses pinprick sensation or the ability to move his legs. Which nerve fibres are blocked first?
1. AA-alpha motor fibres
2. BPreganglionic sympathetic B fibres
3. CA-beta touch and pressure fibres
4. DA-gamma muscle spindle fibres
Answer and explanation in LearnFree account
Question 9 · Medium
A 58-year-old man with five fractured ribs on the left is to receive bupivacaine for pain relief. The resident is reminded that the same dose gives very different blood levels at different sites. With equal doses, which route leads to the highest peak plasma level?
1. ABrachial plexus block
2. BMultiple intercostal nerve blocks
3. CSubcutaneous infiltration
4. DThoracic epidural injection
Answer and explanation in LearnFree account
Question 10 · Easy
A 32-year-old man needs suturing of a scalp laceration in casualty. He says he developed hives and wheezing after a dental injection of procaine some years ago. Which local anaesthetic is least likely to cross-react?
1. AChloroprocaine
2. BLignocaine
3. CTetracaine
4. DBenzocaine
Answer and explanation in LearnFree account
Question 11 · Medium
A 68-year-old woman with ischaemic heart disease is to have continuous femoral and sciatic nerve blocks for leg surgery, needing a large volume of a long-acting local anaesthetic. Which drug is preferred because it is less cardiotoxic than racemic bupivacaine?
1. ATetracaine
2. BRopivacaine
3. CEtidocaine
4. DRacemic bupivacaine
Answer and explanation in LearnFree account
Question 12 · Hard
A 50-kg woman needs excision of a large lipoma on her back under local infiltration. The only solution available is 2% lignocaine with adrenaline 1:200,000. Taking the maximum safe dose of lignocaine with adrenaline as 7 mg/kg, what is the largest volume of this solution that may be used?
1. A35 mL
2. B17.5 mL
3. C175 mL
4. D1.75 mL
Answer and explanation in LearnFree account
Question 13 · Medium
A 3-year-old boy is to have a caudal block after induction of general anaesthesia for orchidopexy. With the child lying on his side, the needle is inserted at the apex of the triangle formed with the two posterior superior iliac spines, and a distinct 'give' is felt. What has the needle just pierced?
1. ASupraspinous ligament
2. BSacrococcygeal ligament
3. CLigamentum flavum
4. DDura mater
Answer and explanation in LearnFree account
Question 14 · Easy
A 30-year-old man is positioned sitting for spinal anaesthesia before a knee arthroscopy. The anaesthetist draws an imaginary line joining the highest points of the two iliac crests to find the interspace. At which level does this line usually cross the spine in an adult?
1. AS2 spinous process
2. BT12 spinous process
3. CL1 spinous process
4. DL4 spinous process
Answer and explanation in LearnFree account
Question 15 · Medium
A 27-year-old woman in labour has an epidural catheter placed. Shortly after 15 mL of 0.25% bupivacaine is given through the catheter, she says her arms feel heavy and she cannot breathe properly. BP is 70/40 mmHg and pulse 48/min, and she soon becomes unresponsive and apnoeic with dilated pupils. What is the most likely cause?
1. ASystemic toxicity from intravascular injection
2. BAmniotic fluid embolism
3. CHigh spinal from an intrathecal catheter
4. DVasovagal syncope from anxiety
Answer and explanation in LearnFree account
Question 16 · Medium
A 64-year-old man with COPD is to have an open colectomy, and the anaesthetist plans a thoracic epidural for analgesia. A student compares epidural with spinal anaesthesia: 1. An epidural can produce a segmental block limited to chosen dermatomes. 2. A spinal block has a faster onset and needs a much smaller dose of drug. 3. The epidural space is found by loss of resistance as the needle passes the ligamentum flavum. 4. A test dose helps detect a catheter that has entered a vein or the subarachnoid space. Which statements are correct?
1. A2, 3 and 4 only
2. B1 and 3 only
3. C1, 2, 3 and 4
4. D1, 2 and 3 only
Answer and explanation in LearnFree account
Question 17 · Hard
A 68-year-old man has a lumbar epidural catheter for analgesia after knee replacement. Enoxaparin 40 mg once daily was started on the evening of surgery, and the catheter was removed 6 hours after the second dose. Eight hours later he has new severe back pain, weakness and numbness of both legs, and urinary retention. What is the next best step?
1. AGive protamine sulphate and observe
2. BEmergency MRI and neurosurgical decompression
3. CStop enoxaparin and reassess in 24 hours
4. DRe-site the epidural to restore analgesia
Answer and explanation in LearnFree account
Question 18 · Hard
A 72-year-old, 60-kg man receives femoral and sciatic nerve blocks with a total of 40 mL of 0.5% bupivacaine for a below-knee amputation. Ten minutes later he has a seizure and then goes into ventricular fibrillation. CPR and defibrillation are started and 20% lipid emulsion is given. How should adrenaline be used during this resuscitation?
1. AIn the standard 1 mg dose every 3-5 minutes
2. BIn small doses of 1 microgram/kg or less
3. CAvoided completely throughout
4. DReplaced by vasopressin throughout
Answer and explanation in LearnFree account

Spinal, epidural and local anaesthesia

A 70-year-old man has spinal anaesthesia with hyperbaric bupivacaine for transurethral resection of a bladder tumour. Ten minutes later the sensory block reaches T2. His pulse falls from 78 to 44/min and BP from 140/80 to 86/50 mmHg. Which mechanism best explains the bradycardia?

A 26-year-old woman is to have an elective caesarean section under spinal anaesthesia at a district hospital. She is anxious because her sister had a severe headache for a week after her own spinal. Which choice of needle most reduces the risk of this headache?

A 45-year-old man receives spinal anaesthesia for a hernia repair. Within the first minutes his feet feel warm and flushed, before he loses pinprick sensation or the ability to move his legs. Which nerve fibres are blocked first?

A 58-year-old man with five fractured ribs on the left is to receive bupivacaine for pain relief. The resident is reminded that the same dose gives very different blood levels at different sites. With equal doses, which route leads to the highest peak plasma level?

A 32-year-old man needs suturing of a scalp laceration in casualty. He says he developed hives and wheezing after a dental injection of procaine some years ago. Which local anaesthetic is least likely to cross-react?

A 68-year-old woman with ischaemic heart disease is to have continuous femoral and sciatic nerve blocks for leg surgery, needing a large volume of a long-acting local anaesthetic. Which drug is preferred because it is less cardiotoxic than racemic bupivacaine?

A 50-kg woman needs excision of a large lipoma on her back under local infiltration. The only solution available is 2% lignocaine with adrenaline 1:200,000. Taking the maximum safe dose of lignocaine with adrenaline as 7 mg/kg, what is the largest volume of this solution that may be used?

A 30-year-old man is positioned sitting for spinal anaesthesia before a knee arthroscopy. The anaesthetist draws an imaginary line joining the highest points of the two iliac crests to find the interspace. At which level does this line usually cross the spine in an adult?