Rakesh 5 Flashcards
1
Q
- A 54-year-old man with a history of COPD undergoes left shoulder
arthroscopic surgery under interscalene brachial plexus block. The operation
was uneventful. In recovery after 30 min the nurse looking after the patient
noticed he was looking pale, with heart rate of 110, BP of 110/70 mmHg,
respiratory rate of 25/min, and saturation of 90 % on room air. On auscultation
there was no wheeze and air entry on left base was reduced. The chest X-ray
in recovery appears normal. What is the most likely cause of his symptoms?
A. Local anaesthetic toxicity.
B. Left phrenic nerve block/palsy.
C. Exacerbation of COPD.
D. Horner’s syndrome.
E. Recurrent laryngeal nerve block.
A
B
- Answer: B
Local anaesthetic toxicity is less likely considering the duration of the operation. Phrenic nerve palsy
is the most likely cause for all the symptoms and signs. The chest X-ray needs to be in inspiratory
phase to show the raised diaphragm of left side. Recurrent laryngeal nerve block is a well-known
complication after interscalene block, which can cause hoarseness of voice due to ipsilateral
paralysis of the vocal cords. The other mentioned complications are possible but are unlikely
2
Q
- A 54-year-old patient is having retinal detachment surgery under
general anaesthetic. During the surgery the patient became bradycardic
with heart rate of 40 beats per minute and blood pressure of 75/40.
What is the fi rst thing would you do?
A. Reduce the inspired inhalation concentration of isofl urane.
B. Give intravenous glycopyrolate 200 mcg.
C. Give intravenous atropine 600 mcg.
D. Stop the surgeon operating and release the muscles of the globe.
E. Give intravenous ephedrine 6–12 mg.
A
D
- Answer: D
The oculo-cardiac refl ex (OCR) can occur secondary to traction on the eye and ocular muscles,
resulting in bradycardia. Occasionally it can cause junctional rhythm or asystole. The aff erent
pathway is ciliary ganglion to ophthalmic division of trigeminal nerve to gasserian ganglion to main
trigeminal sensory nucleus fourth ventricle. The eff erent pathway is the vagus nerve.
The fi rst step in managing OCR is to releasing the traction on the eye. Persistent bradycardia
should be treated with anticholinergic drugs. Intravenous atropine sulphate blocks the peripheral
muscarinic receptors at the heart, and release of traction blocks the conduction at ciliary ganglion
on the aff erent limb of OCR. Atropine or glycopyrrolate can be used to treat this refl ex and it can
be given prophylactically. Hypoxia, hypercarbia, and light anaesthesia potentiate this refl ex and
should be avoided. Retrobulbar block does not guarantee attenuation of this refl ex.
3
Q
- A 65-year-old lady with BMI of 38 had a total knee replacement
under general anaesthesia. Femoral nerve block was performed using
ultrasound. She suff ers from mild asthma and hypertension. The total
tourniquet time was 1 h 40 min. Twenty-four hours postoperative, the
patient complained of paraesthesia in the right foot and is found to have
foot drop. Which of the following is the most likely cause?
A. Pressure injury from the long duration of operation.
B. Ischaemic injury to the calf muscle.
C. Deep vein thrombosis in the calf muscle.
D. Compression injury to the sciatic nerve.
E. Compartment syndrome in the thigh.
A
D
- Answer: D
Foot drop can be defi ned as a signifi cant weakness of ankle and toe. The foot and ankle dorsifl exors include the tibialis anterior, extensor hallucis longus, and extensor digitorum longus. These muscles are supplied by the sciatic nerve. The paresis of sciatic nerve is more like to be due to the insult secondary to the prolonged application of the tourniquet. Pressure injury, ischaemic injury, and DVT are less likely.
4
Q
- An 8-year-old child is rescued 20 min after near-drowning and has a
core temperature of 30 ° C and fi xed dilated pupils. Along with the
resuscitation what would be the appropriate treatment:
A. Intravenous barbiturate infusion.
B. Rapid re-warming to 32–34 ° C.
C. Intravenous steroid therapy.
D. Hypoventilation.
E. Intravenous sodium bicarbonate.
A
B
4. Answer: B
Accidental hypothermia exists when the body’s core temperature unintentionally drops below
35 ° C. Hypothermia can be classifi ed arbitrarily as mild (35–32 ° C), moderate (32–28 ° C), or severe
(<28 ° C). In a hypothermic patient, the absence of signs of life alone is unreliable for declaring death.
5
Q
- A 65-year-old male patient had open prostatectomy under general
anaesthesia. The surgical procedure was complicated, with prolonged
anaesthesia for 5 h, and there was a total blood loss of about 2.5 L. Intraoperatively
he received 6 units of packed cells and he was transferred
to the intensive care unit. In the intensive care unit, the patient was
tachycardic and hypotensive. The peak airway pressure was about
30–35 cm H 2 O. On chest examination there were bilateral lung
crepitations. The most likely cause of his condition is:
A. Cardiogenic shock.
B. Acute myocardial infarction.
C. Sepsis.
D. Transfusion-related reaction.
E. Transfusion-related acute lung injury.
A
E
- Answer: E
The clinical condition presented here is following the transfusion of packed cells. Hence the most
likely diagnosis is transfusion-related acute lung injury (TRALI). TRALI is defi ned as new acute
lung injury occurring during or within 6 h after a transfusion, with a clear temporal relationship to
the transfusion. Another important concept is that acute lung injuries temporally associated with
multiple transfusions can be TRALI because each unit of blood or blood component can carry one
or more of the possible causative agents: anti-leukocyte antibody, biologically active substances,
and other yet unidentifi ed agents.
6
Q
- A 35-year-old male is listed for electroconvulsive therapy. He is
medically fi t but has a family history of allergy to suxamethonium.
You are advised by the consultant to use rocuronium and sugammadex.
Which of the following statements is true regarding sugammadex?
A. Most of the drug is metabolized and excreted by kidney.
B. Sugammadex binds with rocuronium at the neuromuscular junction.
C. The drug forms complex with the rocuronium with a ratio of 1:3.
D. The free plasma concentration of rocuronium increases following complex formation with
sugammadex.
E. It is a modifi ed γ -cyclodextrin with eight side chains and a negatively charged carboxyl
group.
A
E
- Answer: E
Sugammadex is the fi rst selective relaxant binding agent to reverse neuromuscular blockade. It is
a γ -cyclodextrin that forms a tight (1:1) one-to-one complex with rocuronium (vecuronium to a
lesser extent), reducing the plasma concentration of the neuromuscular blocking agents and rapidly
reversing their eff ects. It is a modifi ed γ -cyclodextrin with eight side chains and negatively charged
carboxyl group to increase the affi nity.
7
Q
- As a universal precaution there is a recommendation to use a heat
and moisture-exchange fi lter with each patient. A heat and moistureexchange
fi lter incorporates a high-effi ciency particulate air fi lter of
small size. Which of the following pathogens will pass through the
heat and moisture-exchange fi lter?
A. Pseudomonas aeruginosa .
B. Mycoplasma pneumonia .
C. Mycobacterium tuberculosis .
D. Staphylococcus aureus .
E. Legionella pneumophilia.
A
a
- Answer: C
A standard heat and moisture exchange fi lter is tested to 0.3 μm pore size.
The sizes of the organisms are:
Pseudomonas aeruginosa : 1–3 μm
Mycoplasma pneumoniae : 0.15 μm is the smallest.
Mycobacterium tuberculosis : 2–4 μm length, 0.2–0.4 μm wide
Staphylococcus aureus : 0.6 μm diameter
Legionella pneumophilia : 1–3 μm long, 0.5–1.0 μm wide
8
Q
- A 70-year-old woman is referred to the pain clinic with severe shooting
pains in the upper half of the left side of her face. These are made worse
by eating. Physical examination and all investigations are normal. Simple
analgesics have not provided eff ective pain relief. Which of the following
would be the initial treatment?
A. Carbamazepine.
B. Topical capsaicin ointment.
C. Oral morphine.
D. Transcutaneous nerve stimulation (TENS).
E. Fluoxetine.
A
A
8. Answer: A
Trigeminal neuralgia is an intermittent, usually unilateral, severe neuropathic pain, which can come
on spontaneously or by stimulation of the trigger zone. There is an abnormality in the trigeminal
sensory system. There is signifi cant female preponderance (2:1). Magnetic resonance imaging is
recommended in these patients.
Classifi cation
Type 1 is primary or idiopathic.
Type 2 is secondary to irritation or compression of the trigeminal nerve by tumour or disease,
including multiple sclerosis.
Medical treatment
Response to carbamazepine is almost diagnostic of this condition. Gabapentine, baclofen, and
sodium valproate have also been used.
9
Q
- A 70-year-old patient, who had a hip replacement 2 weeks ago, now
has dislocated the hip. The patient is on ramipril, simvastatin, aspirin,
and dabigatran. Which of the following statements is correct regarding
dabigatran?
A. The drug is licensed for venous thromboembolism (VTE) prophylaxis in AF patients.
B. The drug is in its active form.
C. The drug needs routine coagulation monitoring.
D. The drug is a direct thrombin inhibitor.
E. The drug is metabolized in liver and excreted by kidney in inactive form.
A
e
- Answer: D
Dabigatran is a new oral anticoagulant for prevention of venous thromboembolism. This drug is a specific, competitive, and reversible thrombin inhibitor.
Mechanism of action
Dabigatran is a direct thrombin inhibitor and is used in the form of a pro-drug, dabigatran etexilate.
This is metabolized by plasma esterases into active drug, dabigatran. It prolongs APTT, PT, and TT.
The real advantage of the drug is it does not need routine coagulation monitoring. It does not have
a specifi c antidote
10
Q
- An 88-year-old male patient is admitted with fracture of neck of femur
for left hip hemiarthroplasty. The patient is a known hypertensive, on
atenolol 50 mg and ramipril 5 mg. Following spinal anaesthesia the
blood pressure drops to 60/35 mmHg and his heart rate drops from
80 to 60/min. He has received 1.5 L of Hartman’s solution. The next
step is:
A. To transfuse 500 mL crystalloid and recheck the blood pressure every 1–2 min.
B. To give incremental bolus of 6 mg ephedrine along with the crystalloid.
C. To position the patient’s head downwards and infuse 500 ml crystalloid.
D. To give 250 ml of gelofusion along with the bolus of 6 mg of ephedrine.
E. To give 500 mcg metaraminol as bolus, along with the rest of the crystalloid and recheck
the blood pressure.
A
e
- Answer: E
Central neuraxial block causes reduction of sympathetic outfl ow, which results in reduction of
the sympathetic tone and reduction of the systemic vascular resistance. This is compensated by
increase in heart rate and stroke volume; in a group of geriatric patients these are less eff ective.
Furthermore, this patient is on β -blockers and ACE inhibitors, which, along with less compliant
ventricles, further compounds the problem for the patient. In the elderly patient hypotension
should be treated with cautious use of fl uids and vasopressors. Ephedrine is likely to be ineff ecti
11
Q
- A 50-year-old man with metastatic cancer is listed for intramedullary
nailing of a pathological femoral fracture. For the last 3 months he has
been on 300 mg/day of oral morphine for cancer-related pain control.
What is the most appropriate way to manage his postoperative pain?
A. The patient’s morphine should be temporarily discontinued during the perioperative
period.
B. This patient has reached the upper limit of opioid and should be reduced before the surgery.
C. This patient will be tolerant to opioid analgesia — increasing opioid load would lead to
addiction and should be avoided.
D. Routine postoperative patient-controlled morphine would be adequate.
E. A combination of femoral nerve block and fentanyl patient-controlled analgesia with
shorter lock-out and higher bolus would be appropriate.
A
e
- Answer: E
The principles of acute pain management in the patient who is dependent on high-dose opioids
represent challenges, as it is diffi cult to diff erentiate addiction from dependence and to avoid opioid
withdrawal symptoms. It is also diffi cult to achieve adequate pain management, as tolerance to the
eff ect of postoperative opioids must also be considered.
The aim is to bring acute pain under control. Opioid use in the context of pain/analgesia is unlikely
to lead to addiction. Reducing high background opioid doses acutely may precipitate withdrawal.
Standard postoperative opioid regimes are unlikely to be adequate for opioid-tolerant patients,
who are also less likely to suff er side eff ects such as respiratory depression. Involvement of a
multidisciplinary team will often be necessary to manage behavioural, psychological, psychiatric, and
medical problems encountered in this group of patients.
12
Q
- Twenty-four hours following a normal vaginal delivery a 34-year-old
woman is looking drowsy on routine examination. Her heart rate is
110/min and blood pressure is 85/40 mmHg. Her temperature is noted
to be 38.9 ° C. She is treated with 1 L of crystalloid and oral amoxicillin.
The midwife is concerned and has asked for an anaesthetic review of
the patient. What would be the most appropriate step to follow?
A. Keep giving fl uid until the tachycardia settles.
B. Insert a central venous line to monitor fl uids on the ward.
C. Arrange early transfer to an HDU facility.
D. Ask the midwife to do hourly MEWS on the ward.
E. Advise the obstetrician to refer her to the medical team.
A
c
- Answer: C
During the 2006–2008 triennium, sepsis was the leading cause of direct maternal death, accounting
for 26 direct deaths and with a further 3 deaths classifi ed as ‘late direct’, particularly those
associated with Group A streptococcal infection (GAS).
Most of the deaths occurred in the postpartum period; more than half following lower segment
caesarean section. Seven women died from sepsis that developed after vaginal delivery, illustrating
13
Q
- A 56-year-old male presents for day-case knee arthroscopy. On the day
unit he seems to be slightly confused. Patient is a known alcoholic and
had a few admissions to the hospital with upper gastrointestinal bleeding.
The last hospital letter shows he was diagnosed with end-stage liver
failure. What would be the most appropriate anaesthetic management?
A. Cancel the case and rearrange as an inpatient procedure.
B. Cancel the patient, as anaesthesia carries high risk and this is not a life-threatening
situation.
C. Call the bed manager, arrange an inpatient bed and do the case.
D. Patient would need to be intubated as he is at high risk of aspiration.
E. After the procedure he should be followed up by an alcohol-awareness team.
A
a
- Answer: B
Patients with end-stage liver disease are at signifi cant risk of mobility and mortality after anaesthesia
and surgery. Medical and surgical intervention may exacerbate liver dysfunction and result in
life-threatening hepatic failure. End-stage liver disease should constitute a relative contraindication
to surgical intervention except for life-threatening situations. Death from liver disease and
alcoholism increases by 7 % a year
14
Q
- A 70-year-old man is brought to A&E following a collapse at home. The
paramedics gave him 1000 mL of crystalloid and noticed a pulsating
swelling in the abdomen. On arrival in A&E his BP is 100/60 mmHg,
heart rate is 110/min, and GCS 15/15. The FAST scan was positive
and CT scan showed leaking aneurysm. Which of the following is not
appropriate management?
A. Check NIBP in both arms.
B. Good preoperative assessment.
C. Administer IV fl uids to restore the BP.
D. Administer IV fl uids to aim for a MAP of 90 mmHg.
E. Get blood products as soon as possible.
A
d
- Answer: C
Ruptured AAA is a surgical emergency and a rapid preoperative evaluation is required. The fi rst
response of many anaesthetists confronted with a patient with a ruptured AAA is to administer
intravenous fl uids to rapidly restore blood pressure to near-normal levels. However, excessive
administration of fl uids prior to clamping of the aorta will increase bleeding through thrombus
dislodgement and dilution of clotting factors. A brief and targeted preoperative assessment should
be made. Most patients will have extensive atherosclerotic and smoking-related diseases. Many
patients have signifi cant coronary artery disease, which is not always obvious from history and
examination. Diabetes, hypertension, and renal impairment are also common. Blood pressure
should be checked non-invasively in both arms as there may be brachiocephalic and subclavian
artery stenosis. If there is a diff erence in readings, the higher reading should be use.
??????????????????????sbp of 90 not map????????
15
Q
- You are asked to review a 32-year-old woman in the post-delivery ward.
Twenty-four hours post forceps delivery, she is complaining of left foot
drop. She had a labour epidural for pain relief, which worked very well.
On examination she has good power in both legs and there are no other
neurological issues. What is the most likely cause?
A. Epidural haematoma.
B. Dense block from the top up.
C. Epidural abscess.
D. Neuropraxia of the common peroneal nerve from forceps delivery.
E. Spinal cord compression.
A
D
- Answer: D
Postpartum foot drop is caused by damage to the lumbosacral nerve trunk or, less frequently, the
common peroneal nerve. The lumbosacral trunk (L4 and L5) is compressed between the ala of
the sacrum and the descending foetal head. It may also occur during a forceps delivery. Typically, it
occurs in a mother of short stature with a large baby. The result is a unilateral foot drop, with loss
of sensation and/or paraesthesia along the lateral calf and foot. Common peroneal nerve damage
may occur due to improper or prolonged positioning during lithotomy, and sensory defi cit may be
limited to the dorsum of the foot. Nerve-conduction studies are required to identify the site of
neural damage with any certainty.
16
Q
- A 24-year-old man is brought to A&E following a motorbike accident.
On arrival his initial assessment was clear airway, tachypnoeic,
tachycardic, and hypotensive. He was immediately given oxygen by
mask and intravenous access was secured with two 16-g cannula.
He responded to an initial 10 mL/kg fl uid bolus. His CT scan shows
an unstable spinal fracture at a level of T10. After 10 min his blood
pressure dropped again. What is the most likely reason?
A. Neurogenic shock.
B. Septic shock.
C. Bleeding from an undiagnosed injury.
D. Allergic reaction.
E. Sympathetic hyperrefl exia.
A
C
- Answer: C
Maintenance of an adequate circulation is essential in spinal cord injury in order to minimize
secondary ischaemic damage to the injured cord. Hypotension must be treated promptly with
fl uid boluses in the fi rst instance. In the polytrauma patient who is hypotensive, hypovolaemia secondary to haemorrhage from concurrent injuries must be excluded according to ATLS principles.
Remember that the patient with a high spinal cord injury will not complain of pain from a fractured
pelvis or other injuries. Intra-abdominal bleeding is more diffi cult to diagnose when the abdominal
muscles are fl accid.
Neurogenic shock
Hypotension occurs with lesions above T6 due to loss of sympathetic autonomic function and
unopposed parasympathetic function. Vasoconstrictor tone is lost and venous pooling occurs.
Loss of cardiac accelerator fi bres results in bradycardia and patients are unable to increase cardiac
output by changes in heart rate. Although the duration of neurogenic shock is variable, recovery
tends to be incomplete and postural hypotension can be a persistent problem.
Septic shock is not a acute presentation in trauma patients.
17
Q
- A 70-year-old patient with coronary artery disease is listed for an elective
coronary artery bypass; he has moderate-to-severe left ventricular failure
on his most recent echo-cardiogram. During the surgery, after weaning
from cardiopulmonary bypass (CPB), there is persistent hypotension
with low cardiac index despite the administration of inotropic drugs.
What would be the specifi c management of this condition?
A. Correct hypothermia.
B. Correct electrolyte imbalance.
C. Insert an intra-aortic balloon pump.
D. Restart the CPB as soon as possible.
E. Consider ECMO.
A
C
- Answer: C
Intra-arotic balloon pumps (IABP) are used for stabilization of patients with acute myocardial
infarction referred for urgent cardiac surgery. IABP support is often initiated in the cardiac
catheterization laboratory and continued through the perioperative period. Elective placement
is considered in high-risk patients such as those with signifi cant left main stem disease, severe
LV dysfunction (ejection fraction <30 % ), congestive heart failure, cardiomyopathy, chronic renal
failure, or cerebrovascular disease. Weaning from cardiopulmonary bypass may be diffi cult in cases
where aortic cross-clamping is prolonged, revascularization is only partially achieved, or preexisting
myocardial dysfunction is present. Separation from cardiopulmonary bypass may be marked by
hypotension and a low cardiac index despite the administration of inotropic drugs. The use of
IABP in this setting decreases LV resistance, increases cardiac output, and increases coronary and
systemic perfusion, facilitating the patient’s weaning from cardiopulmonary bypass.
18
Q
- A frail 75-year-old woman was brought to A&E with a Colle’s fracture
of the left wrist. A junior orthopaedic trainee manipulated the wrist
using intravenous regional anaesthesia (Bier’s block) with 30 mL
of 0.25 % levobuvipacaine. Shortly after the cuff was defl ated, the
patient had symptoms of confusion, seizure, and hypotension, without
cardiorespiratory arrest. The most appropriate management would be:
A. Follow the ALS guidelines.
B. Give 10 mg of lorazepam.
C. Secure the airway.
D. Give an initial intravenous bolus injection of 20 % lipid emulsion 1.5 mL/kg over 1 min.
E. Refer the patient to intensive care.
A
d
- Answer: D
This lady has local anaesthetic toxicity without cardiorespiratory arrest, as the local anaesthetic used
was levo-bupivacaine rather than prilocaine, which is advised for Bier’s block as it is less cardiotoxic.
Signs of severe toxicity include:
sudden alteration in mental status, severe agitation or loss of consciousness, with or without
tonic-clonic convulsions.
cardiovascular collapse: sinus bradycardia, conduction blocks, asystole, and ventricular
tachyarrhythmias
Local anaesthetic (LA) toxicity may occur sometime after an initial injection.
Immediate management steps are:
Stop injecting the LA.
Call for help.
Maintain the airway and, if necessary, secure it with a tracheal tube.
Give 100 % oxygen and ensure adequate lung ventilation (hyperventilation may help by
increasing plasma pH in the presence of metabolic acidosis).
Confi rm or establish intravenous access.
Control seizures: give a benzodiazepine, thiopental, or propofol in small incremental doses.
19
Q
- A 35-year-old patient was admitted to critical care with pneumonia.
He was ventilated and treated with antibiotics. Forty-eight hours
post admission his airway pressure is 35 cmH 2 O and he is on Fi O 2 of
80 % with a P aO 2 of 10 kPa. Chest X-ray shows bilateral asymmetrical
consolidation. Which of the following criteria fi ts for acute lung injury?
A. Acute onset.
B. Presence of bilateral infi ltrates on chest-X-ray consistent with oedema.
C. PAWP <18 mmHg or clinical absence of left atrial hypertension.
D. Hypoxaemia with P aO2 / Fi O 2 <40 (if P aO 2 / Fi O 2 <27, the term ARDS is used).
E. All of the above answers are criteria for acute lung injury.
A
d
- Answer: E
Acute lung injury (ALI) is a condition that is diagnosed clinically and radiologically based on the
presence of non-cardiogenic pulmonary oedema and respiratory failure in a critically ill patient.
The diagnostic criteria for ALI are:
acute onset
presence of bilateral infi ltrates on CXR consistent with oedema
PAWP <18 mmHg or clinical absence of left atrial hypertension
hypoxaemia, with P aO 2 / Fi O 2 < 40 (if P aO 2 / Fi O 2 < 27, the term ARDS is used).
20
Q
- A 31-week primigravida presented to A&E complaining of headache
and blurred vision.
Her blood pressure is 150/109 mmHg and the
urine shows proteinuria. Whilst she is waiting to be reviewed by the
obstetrician, her blood pressure rises to 157/115 mmHg. What is the
next step in the management of the patient?
A. Transfer the patient immediately to theatre for emergency LSCS.
B. Give her a bolus of 100 mg labetalol.
C. Restrictive fl uid therapy.
D. Load her with 4 g magnesium sulphate and start her on a magnesium sulphate infusion.
E. Check her FBC and clotting.
A
D
- Answer: D
Consider giving intravenous magnesium sulphate to women with severe pre-eclampsia who are in a
critical care setting if birth is planned within 24 h. If considering magnesium sulphate treatment, use
the following as features of severe preeclampsia:
severe hypertension and proteinuria or
mild or moderate hypertension and proteinuria with one or more of the following:
symptoms of severe headache
problems with vision, such as blurring or fl ashing before the eyes
severe pain just below the ribs or vomiting
papilloedema
signs of clonus (3 beats)
liver tenderness
HELLP syndrome
platelet count falling to below 100 × 10 9 /L
abnormal liver enzymes (ALT or AST rising to above 70 IU/L).
Use the collaborative eclampsia trial regimen for administration of magnesium sulphate:
loading dose of 4 g should be given intravenously over 5 min, followed by an infusion of 1 g/h
maintained for 24 h
recurrent seizures should be treated with a further dose of 2–4 g given over 5 min.
21
Q
- A 21-year-old woman is brought to A&E after ingesting 200 g of
paracetamol.
She is initially managed with N-acetylcysteine and referred
to the high-dependency unit. Twenty-four hours later her Glasgow Coma
Scale was reduced to 8/15 and her blood results show pH 7.28, PaO 2
12 kPa, PaCO 2 5.1 kPa, HCO 3 16 mmol/L, PT 110 s, and creatinine 210
mmol/L. The appropriate management following intubation should be:
A. Early referral to specialist liver centre for liver transplant.
B. Refer to the haematology team to improve her clotting.
C. Refer to the psychiatric team before discharging home.
D. Give her another dose of N-acetylcysteine.
E. Early haemofi ltration to avoid renal failure.
A
A
- Answer: A
Paracetamol overdose is a life-threatening occurrence and is likely after ingestion of > 10–15 g of
paracetamol. Paracetamol is rapidly absorbed and metabolized by conjugation in the liver. Hepatic
necrosis occurs due to toxicity of an alkylating metabolite normally removed by conjugation with
glutathione. With overdose, glutathione is rapidly depleted and may already be low in cases of starvation,
and among alcoholics and those with HIV, thus predisposing these groups to an increased risk of toxicity.
Toxicity is usually asymptomatic for 1–2 days, although laboratory assessment of liver function may
become abnormal as early as 18 h after ingestion. Hepatic failure develops after 2–7 days.
Complications
The major complication is hepatic (with or without renal) failure. A rise in prothrombin time, INR,
and bilirubin are early warning signs of signifi cant hepatic damage and this should prompt early
referral to a specialist centre.
Guidelines for referral to a specialist liver centre
Arterial pH < 7.3.
INR > 3 on day 2 or > 4 thereafter.
Oliguria and/or rising creatinine.
Altered conscious level.
Hypoglycaemia.
Guidelines for liver transplantation
Arterial pH < 7.3.
All the following:
PT > 100, INR > 6.5
creatinine > 200 mol/L
grade 3–4 encephalopathy.
High lactate levels ( > 3.5 mmol/L at 4 h and 12 h) and low factor V levels are also associated with a
poor outcome if not transplanted.
22
Q
- A 28-year-old female patient with a history of asthma arrives in A&E
by ambulance. She is short of breath with audible wheeze. She has
used her inhalers repeatedly over the last few hours but she has not
improved and is unable to talk. On arrival her respiratory rate is 30/
min with oxygen saturation of 90 % . On arrival she is treated with 10 L of
oxygen and nebulized salbutamol 5 mg. 10 min after the treatment her
respiratory rate is still 28/min and saturation 91 % . The clinical condition
has not improved. Arterial gas shows P aCO 2 of 9 kPa and P O 2 of 8 kPa.
What would be the most appropriate management?
A. Nebulized B2-agonist (e.g. salbutamol).
B. Intravenous corticosteroids for 24 h.
C. Intravenous magnesium sulphate 2 g slowly.
D. Intravenous aminophylline 5 mg/kg.
E. Rapid sequence induction and positive pressure ventilation.
A
e
Indications for mechanical ventilation are:
increasing fatigue
respiratory failure — rising P aCO 2 , falling P aO 2
cardiovascular collapse
23
Q
- A 65-year-old male is scheduled for elective laryngectomy. He suff ers
from COPD, coronary artery disease, and had three coronary stents
inserted 3 years ago. He smokes 20 cigarettes a day. His nasendoscopy
shows a subglottic tumour occupying two-thirds of the airway. He says
that he is unable to lie fl at and presents with an inspiratory stridor.
What is the most appropriate method of induction in this patient?
A. He should have an intravenous induction.
B. He should have gas induction, muscle relaxant, and laryngoscopy.
C. He should have gas induction and asleep fi breoptic intubation.
D. He should have an awake fi breoptic intubation and then intravenous induction.
E. He should have a tracheostomy with local anaesthetic and then general anaesthetic.
A
E
- Answer: D
This patient has an airway compromised by a tumour and there is a potential to obstruct the airway
after administration of neuromuscular blockers. The intubation would then be extremely diffi cult as
the anatomy is altered by the tumour and it would be narrow.
Seventy two cases reported in the National Audit Project 4: Major Complications of Airway
Management in the United Kingdom (NAP4) involved an airway problem in association with an acute
or chronic disease process in the head, neck, or trachea. Approximately 70 % of these cases were
associated with obstructive lesions within the airway.
24
Q
- A 34-year-old biker had a motorbike accident with open knee injury.
He had general anaesthesia for knee washout and ligament repair.
He has an arterial tourniquet, infl ated at right thigh level. During the
operation the blood pressure rose to 180/90 mmHg. Regarding the use
of arterial tourniquets, which one of the following statements is most
accurate?
A. Every 30 min of tourniquet infl ation increases the risk of nerve damage by 50 % .
B. Older age is an independent predictor of nerve damage following prolonged tourniquet
time.
C. Ketamine reduces the hypertensive eff ect of the tourniquet if given perioperatively.
D. Pain from the surgical site becomes a problem after 1 h of continuous tourniquet infl ation,
and may cause hypertension.
E. The use of a tourniquet has no implications for cerebral blood fl ow.
A
b
- Answer: C
Tourniquet is used widely for limb procedures. Complications are rare but can be severe. Most
literature recommends a maximum infl ation time of 1.5–2 h, followed by break of 10–15 min,
which should be used to allow regeneration of muscle ATP. After 15 and 45 min a physiological
conduction block aff ecting both motor and sensory nerve fi bres prevents nerve transmission to and
from distal to the tourniquet site.
The pain from the tourniquet site itself may be the cause of the ‘tourniquet hypertension’ seen
with increasing duration of tourniquet infl ation. This can be treated by use of ketamine (low dose),
clonidine, and even topical local anaesthetic cream.
Every 30 min a tourniquet is infl ated there is a threefold increase in the incidence of neurological
damage. Younger patients are more likely to have neurological damage following prolonged
tourniquet time. Pain transmission from distal to the tourniquet will be absent after 1 h. Changes
in CO 2 can cause a marked change in cerebral blood fl ow. Ketamine has been shown to reduce
‘tourniquet hypertension’.
25
Q
- A 28-year-old woman was brought to A&E following overdose by nasal
inhalation of cocaine. Her GCS was 3/15, heart rate was 165/min,
blood pressure was 110/60 mmHg, and respiratory rate was 6/min
on 15 L of oxygen and oxygen saturation of 94 % with Guedels airway
and mask ventilation. On arrival she was intermittently convulsing
with supraventricular and ventricular tachycardia. Arterial blood gas
analysis on arrival showed respiratory and metabolic acidosis. She
was immediately intubate and ventilated. What would be the most
appropriate next step?
A. Treat the convulsions by loading dose infusion of phenytoin 1.2 g (15 mg/kg).
B. Treat the hypotension by noradrenaline infusion (0.05 mcg/kg/min).
C. Fluid resuscitation.
D. Administer initial bolus of lipid emulsion 1.5 mL/kg of 20 % followed by infusion.
E. Correction of respiratory and metabolic acidosis.
A
e
- Answer: D
The patient was presented in a comatose state, suff ering from seizures and marked cardiovascularly
instability. This requires treating the patient as per the resuscitation guidelines. Hence once initial
resuscitation and tracheal intubation have been achieved, the appropriate treatment would be
to manage cocaine toxicity. Cocaine is both a local anaesthetic and lipophilic; the appropriate
.step is immediate administration of lipid emulsion. A 20 % lipid emulsion (Intralipid; Frasenius
Kabi, Runcorn, UK) is administered intravenously as an initial bolus dose of 1.5 mL/kg (120 mL),
followed by an infusion of 15 mL/kg/h (380 ml) over 20 min.
26
Q
- A 17-year-old boy is brought to A&E with a reduced level of
consciousness and rapid, deep, sighing breathing. On observation,
his heart rate is 125/min, blood pressure 120/65 mmHg, respiratory
rate 22/min, saturation of 99 % , and GCS 13/15. A urine dipstick
demonstrates signifi cant ketonuria. The blood gas is as follows: pH 6.89,
PO 2 64 kPa, PCO 2 1.6 kPa, HCO 3 4, lactate 2.1, Na + 114, K + 6.9, glucose - What is the most appropriate initial treatment?
A. Immediate intubation and ventilation.
B. Urgent haemofi ltration to treat acidosis and hyperkalaemia.
C. Intravenous bicarbonate slow infusion.
D. Cautious fl uid resuscitation with insulin infusion at 0.1 unit/kg/h until ketonaemia resolves.
E. Fluid resuscitation with insulin sliding scale adjusted to blood glucose level.
A
d
- Answer: A
The diagnosis here is severe diabetic ketoacidosis (DKA) with associated acidosis and shortness of
breath along with hyperkalaemia. It requires critical care admission with immediate resuscitation and
monitoring. The acidosis should be treated by fl uid resuscitation and shutting off ketone production.
Hyperkalaemia will also be treated by insulin therapy. Rapid fl uid resuscitation has a risk of cerebral
oedema, hence carefully monitored resuscitation with CVP is appropriate along with insulin therapy.
Classical management of DKA focuses on using fl uids and insulin to lower elevated blood glucose.
Patients with DKA have a signifi cant fl uid defi cit and are often water-depleted by up to 100
mL/kg, as well as associated electrolytes defi cit. A fi xed-rate insulin infusion at 0.1 units/kg is
recommended, which will lead to suppression of ketogenesis, reduction of glycosaemia, and
correction of electrolyte imbalance.
The aim is to reduce blood ketones by 0.5 mmol/L/h, increase the bicarbonate by 3 mmol/L/h,
reduce the blood glucose by 3 mmol/L/h and maintain potassium concentration between
4.0 and 5.0 mmol/L. Insulin is infused at fi xed rate of 0.1 U/kg/h. The response to insulin infusion
pump is reviewed after 1 h. If blood glucose is not dropping by 5 mmol/h and capillary ketones
by 1 mmol/L, the infusion rate is increased by 1 U/h. The increase in insulin infusion rate may be
repeated hourly if necessary to achieve reduction in blood glucose and capillary ketones. Monitor
blood glucose, capillary ketones, and urine output hourly
27
Q
- Regarding the nerve supply of the muscles of the larynx, which of the
following muscles is supplied by the superior laryngeal nerve?
A. Thyroarytenoid.
B. Posterior cricoarytenoid muscles.
C. Lateral cricoarytenoids.
D. Cricothyroid muscle.
E. Arytenoid muscle.
A
c
- Answer: D
The nerve supply of the larynx is derived from the vagus nerve. The nerves are the superior
laryngeal nerve and the recurrent laryngeal nerve.
The superior laryngeal nerve arises from the middle of the ganglion nodosum and in its course
receives a branch from the superior cervical ganglion of the sympathetic. It descends, by the side of
the pharynx, behind the internal carotid artery and, below and anterior to greater cornua of hyoid
bone, divides into two branches:
internal laryngeal nerve supplies mucous membrane down to the vocal cords
external laryngeal nerve supplies cricothyroid muscle and inferior constrictor muscle of the
pharynx.
The recurrent laryngeal nerve:
supplies all intrinsic laryngeal muscles except the cricothyroid, and the mucous membrane of
the larynx below the vocal cords, which is innervated by the external branch of the superior
laryngeal nerve
motor to all intrinsic muscles of larynx and sensory supply below cords.
28
Q
- Regarding the gag refl ex, which of the following cranial nerves is the
eff erent pathway for the gag refl ex?
A. Cranial nerve XI.
B. Cranial nerve V.
C. Cranial nerve VII.
D. Cranial nerve X.
E. Cranial nerve IX.
A
d
- Answer: D
The pharyngeal refl ex or gag refl ex is a refl ex contraction of the back of the throat, evoked by
touching the soft palate or sometimes the back of the tongue. The gag refl ex involves elevation
and constriction of the pharynx following stimulation of the posterior pharyngeal wall. The aff erent
pathway is via the glossopharyngeal nerve (IX), the eff erent pathway is via the vagus (X). The clinical
relevance of an absent gag refl ex is in indicating an airway at risk or as part of brain-stem death testing
29
Q
- An 11–month-old child is on your list for adenotonsillectomy under general
anaesthesia. The routine examination reveals a soft systolic murmur; the
rest of the examination is normal. He has no history of shortness of breath.
The parents are very anxious. The appropriate action you will take is:
A. Proceed with the surgery.
B. Proceed with the surgery with antibiotic prophylaxis.
C. Proceed with the surgery and inform paediatric anaesthetist.
D. Postpone the surgery and refer the patient to GP.
E. Postpone the surgery and organize urgent echo.
A
d
- Answer: D
This case is not urgent and should be postponed for further investigation by the cardiologist.
The parents are very anxious and a full explanation would be very useful via a letter to their GP.
In an infant with a murmur, a history of recurrent chest infections, cyanosis, tachypnoea, sweating,
feeding diffi culties, and failure to thrive is suggestive of pathological heart disease. Most congenital
cardiac disease is identifi ed before 3 months of age, but any child under 1 year with a murmur
should be referred to a paediatric cardiologist before anaesthesia, even if asymptomatic, as
signifi cant lesions can be slow to presen
30
Q
- Which statement best describes the correct mechanism of action of the
following antiemetics?
A. Dexamethasone has been shown to downregulate 5-HT 3 receptors.
B. Ondansetron is a 5HT 2 receptor antagonist acting in the chemoreceptor trigger zone.
C. Haloperidol causes central dopaminergic (D2) blockade and post-synaptic GABA antagonism.
D. Cyclizine is a histamine H1 antagonist at as well as having activity at the muscarinic receptors.
E. Metoclopramide acts as an atiemetic via 5HT 3 receptors centrally and peripherally.
A
d
- Answer: D
The steroids’ mechanism of action is unknown. Ondansetron antagonizes 5HT3 receptors centrally
and peripherally; haloperidol causes central dopaminergic (D2) blockade and post-synaptic GABA
antagonism; cyclizine is a competitive histamine H 1 antagonist and blocks centrally located H1
receptors and also has some anticholinergic activity at the muscarinic M1, M2, and M3 receptors.
The antiemetic eff ect of metoclopramide seems to be mediated by central dopaminergic (D2)
blockade and a decrease in the sensitivity of nerves supplying aff erent information to the vomiting
centre.
