MCQ 1 Flashcards
The management of local anaesthetic toxicity includes:
A. suxamethonium
B.-blockers
C. vasopressors
D. hyperventilation
E. bretylium
- A. false B. false C. true D. false E. true
Local anaesthetic toxicity presents as a reduction in myocardial contractility, conductivity and excitability with inhibition of cerebral activity.
Cardiovascular effects require inotropes, vasopressors and fluids for hypotension. Bretylium is the only anti-arrhythmic drug recommended for resuscitation but it too can cause hypotension if administered intravenously. It is recommended that it should not be given with catecholamines. Fitting should be controlled using the ABC regime
Sumatriptan:
A. has an antiemetic property
B. is a 5-hydroxytryptamine (5-HT) antagonist
C. is used in the treatment of migraine
D. does not cross the blood-brain barrier
E. can cause arrhythmias
- A. true B. false C. true D. true E. true Sumatriptan is a 5-HT1 agonist. Its main indication is in the management of migraine but it also has antiemetic properties. This group of drugs should be used with caution, if at all, in ischaemic heart disease and hypertension due to a vasoconstrictor effect. It can cause bradycardia or tachycardia
In pregnancy:
A. fatty liver changes occur most often in the second trimester
B. there is no change in the severity of bronchial asthma
C. sickle cell crises are more common in the first trimester
D. haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome is a variant of pre-eclamptic toxaemia E. systemic lupus erythematosus (SLE) becomes worse
A. false B. true C. false D. false E. true
○Acute fatty liver of pregnancy (AFLP) is of unknown cause. It mainly occurs in the third trimester but can be seen from 20 weeks onwards. The mother becomes very ill very quickly but fatty liver recovers following immediate delivery of the foetus. It presents with non-specific symptoms of abdominal pain, malaise, nausea and vomiting, fever and jaundice develop over one week. The differential diagnosis of jaundice in pregnancy includes a viral hepatitis, cholestasis, bile duct obstruction, alcohol related liver disease or an autoimmune disease.
Pre-eclampsia is frequently present.
○On average bronchial asthma is not affected by pregnancy. Some improve, some get worse and many are the same. ○ Sickle cellcrises result in a 1% mortality, which is usually precipitated by infection or pre-eclampsia.
○ Haemolytic anaemia, elevated liver enzymes and low platelets occur in up to 20% of patient with pre-eclampsia but it is not a variant of pre-eclamptic toxaemia. ○ If patients with SLE conceive then 50% will have a serious exacerbation and their condition will deteriorate.
In a patient with well controlled insulin dependent diabetes, for elective surgery:
A. glucose free solutions should be used
B. hourly urine glucose estimations should be made preoperatively C.-blockers are contraindicated
D. volatile agents should not be used
E. the full morning dose of insulin should be given on the day of surgery
A. false B. false C. false D. false E. false
A regime of intravenous glucose, potassium and insulin should be commenced on the morning of surgery in place of normal breakfast and the normal dose of insulin. Blood sugar should be monitored 3 hourly before and after surgery but hourly during surgery and in the immediate recovery period. -blockers may mask hypoglycaemia and should be avoided if possible, but are contraindicated in severe peripheral arterial disease, uncontrolled heart failure, bradycardia and bronchial asthma.
Concerning local anaesthesia for rigid bronchoscopy in a 70kg adult:
A. The superior laryngeal nerve should be blocked
B. The internal laryngeal nerve is blocked
C. Amethocaine can be given orally
D. Cricothyroid puncture can be used
E. 10ml of 4% lidocaine is used
A. true B. true C. false D. true E. false
○ The superior laryngeal nerve carries sensation from above the vocal cords. The internal laryngeal nerve carries sensation from below the vocal cords.
○ Amethocaine was supplied as a lozenge but has been withdrawn as lidocaine is safer for bronchoscopy and cystoscopy.
○ Cricothyroid puncture is used to inject local anaesthetic into the trachea.
○ Lidocaine for surface use is available as 2% and 4%.
**The maximum recommended dose is 3mg/kg and a disposable spray contains 4ml
Nitrous oxide in the cuff of a tracheal tube:
A. increases with time
B. decreases after the nitrous oxide administration is discontinued
C. creates a pressure that is lower in high volume, low pressure cuffs
D. causes a decrease in capillary blood flow
E. can cause necrosis of the tracheal mucosa
A. true B. true C. false D. true E. true Nitrous oxide diffuses into air filled spaces quicker than the nitrogen diffuses out. It will increase the volume and pressure in the cuff of a tracheal tube. Some practitioners fill their cuffs with an oxygen/nitrous oxide mixture to prevent this happening. The process is reversible. Increased pressure causes ischaemia of the tracheal mucosa and over time will lead to necrosis.
In a patient with Duchenne muscular dystrophy and kyphosis with Q waves and inverted T waves on the ECG who is listed for Harrington rod insertion:
A. suxamethonium should not be used
B. a stress test ECG should be requested
C. if the creatinine phosphokinase (CPK) is elevated, surgery should be postponed
D. if there is no chest pain it is safe to proceed E. shortness of breath is a contraindication for surgery
- A. true B. false C. false D. false E. true ○ Suxamethonium and volatile agents should be avoided in Duchenne muscular dystrophy. They cause respiratory, metabolicand cardiac effects of unknown origin.
○ An echocardiogram or angiography will give more information. The patient may not be able to co-operate for a proper stress test. The creatinine phosphokinase (CPK) is a non-specific enzyme. It is grossly elevated in the early stages of the dystrophy when most muscle wasting is occurring.
○ Chest pain is not a good indicator of cardiac function, particularly in the sedentary patient.
○ Before proceeding the nature and cause of the breathlessness should be assessed. The kyphosis may be the cause of the breathlessness, which will hopefully be improved by the operation.
Diamorphine given epidurally:
A. has a faster onset of action than morphine
B. first pass metabolism occurs
C. has no active metabolite
D. 20mg diamorphine is equivalent to 20mg oxycodone E. causes less delayed respiratory depression than morphine
A. false B. true C. false D. false E. false
○ Diamorphine is more water soluble and more lipid soluble than morphine and so passes the blood-brain barrier quicker than morphine, when given systemically. But once in the CSF it looses the two acetyl molecules and becomes morphine, which is the form in which it is active. In this respect its actions are the same as morphine. It is metabolised in the liver to active morphine 6 glucoronide and inactive morphine 3 glucoronide. All morphine related drugs are subject to a “first pass effect” when they pass through the liver. This effect is limited to oral preparations as the liver stands between the bowel and the systemic circulation. Some practitioners prefer diamorphine for subarachnoid block as the powder can be reconstituted to give a preservative free solution. Oxycodone is about twice as potent as morphine.
The MAC50 of volatile agents is decreased with:
A. a decrease in oxygen tension
B. a decrease in carbon dioxide tension
C. treatment with lithium
D. treatment with chlorpromazine
E. treatment with clonidine
. A. false B. true C. true D. true E. true Reduced carbon dioxide tension by itself leads to a loss of awareness. Lithium is used in the treatment of mania. An excess leads to apathy and eventually coma
- Proximal myopathy occurs with:
A. diabetes mellitus
B. treatment with steroids
C. untreated thyrotoxicosis
D. subacute combined degeneration of the spinal cord
E. alcoholism
A. false B. true C. true D. false E. true
○ Proximal muscle weakness occurs with prolonged, high doses of steroids, thyrotoxicosis and the associated conditions of myasthenia gravis and hypokalaemic periodic paralysis.
○ Eaton Lambert syndrome affects proximal muscles.
○ Hypocalcaemia, rickets and any cause of osteomalacia may affect proximal muscles. ○ Subacute proximal myopathy can be caused by many drugs including chronic alcohol abuse, diamorphine, clofibrate, chloroquine, lithium and quinine. ○ Subacute combined degeneration of the spinal cord is due to vitamin B12 deficiency. It is combined spinal cord and peripheral nerve damage.
○ Diabetes causes a systemic and autonomic neuropathy.
A decrease in blood pressure after carotid endarterectomy can be due to:
A. loss of cervical sympathetic tone
B. loss of chemoreceptor function
C. loss of baroreceptor function
D. haemorrhage
E. arrhythmias
A. true B. false C. true D. false E. false To perform a carotid endarterectomy the skin supplied by the roots of C3 and 4 are blocked by a deep or superficial cervical plexus block. The lesser occipital and transverse cervical nervessupply the neck. The carotid bifurcation is also blocked to prevent abnormal cardiac effects when the carotid sinus is manipulated.
Concerning post traumatic acute renal failure (ARF):
A. Mortality is 50%
B. Mannitol is indicated in the management
C. The oliguric phase lasts 10 days
D. Disseminated intravascular coagulation (DIC) can occur
E. There is an increased urinary urea level with normal creatinine level
- A. false B. true C. false D. true E. false
The factors that predispose to acute renal failure are hypocalcaemia, aciduria and myoglobinuria.
The aims of treatment are to address these factors by:
• A urine output of 100ml/h
• Test urine regularly for pH and myoglobin
• If the urine pH is 7.0. It has been shown that 100mmol of sodium bicarbonate, which can be repeated, is beneficial
• If the urine pH is 7.0 give acetazolomide 500mg iv, which can be repeated every 4h. This drug has not been shown to be consistently beneficial
• Mannitol is used to promote diuresis
• Loop diuretics should be avoided as they acidify the urine
In a Shrader valve connection:
A. different sized collars are used for different gases
B. the nitrous oxide pipeline pressure is 600kPa
C. there is a non-return valve
D. after maintenance work on the pipelines, testing by an oxygen analyser is sufficient
E. the probe can be twisted in the wall unit
- A. true B. false C. true D. false E. false The Shrader probe is similar for all gases. The gas specific feature is the diameter of the collar, which is specific to fit the wall socket. The pipeline pressure is 400kPa. The wall socket includes a seal to block the flow of gas when the probe is removed. After maintenance the line should be tested for both oxygen and nitrous oxide. The British standard states that the probe should not twist while in the wall outlet. To prevent this the collar has a notch. The socket has a spring loaded outer ring. When this is depressed the probe is released and ejected.
When nitrous oxide is used in contrast studies of cerebral vessel the intracranial pressure is increased by the use of: A. oxygen
B. carbon dioxide
C. air
D. nitrogen E. sevoflurane
- A. false B. true C. false D. false E. true Sevoflurane, carbon dioxide and nitrous oxide are known cerebrovascular vasodilators. They will increase regional blood flow and regional blood volume and hence raise intracranial pressure
The anatomical features of the right side of the lung include:
A. no Sibson’s fascia
B. seven broncho-pulmonary segments
C. one fissure
D. relationship to an azygos vein
E. two pulmonary veins
A. false B. false C. false D. true E. false The right lung has two fissures. The oblique fissure separates the middle lobe from the lower lobe. It follows a line from the second vertebral spine to the sixth costochondral junction. The horizontal (transverse) fissure separates the upper lobe from the middle lobe. It follows a line from the fourth costochondral junction to join the oblique fissure in the axillary line. Relationships of the right lung: Apex – extends into the root of the neck. The suprapleural membrane and pleural cupola are superior. The subclavian artery leaves a groove on the mediastinal surface of the lung. Other relationships on the right are: • The superior vena cava • Right atrium lies anterior to the hilum • The azygos vein arches over it The bronchopulmonary segments of the right lung are: • Upper lobe: apical, posterior and anterior • Middle lobe: lateral and medial • Lower lobe: apical, medial basal (cardiac), anterior, lateral and posterior
A decrease in oxygenation after haemodialysis could be due to:
A. increased shunt
B. increased A-a difference
C. hypotension
D. increased pH
E. bicarbonate dialysis
- A. false B. false C. true D. true E. true The cause of post dialysis hypoxia is not clear. Shunt, water overload and acidosis can lead to hypoxia but are unlikely to be present after dialysis. Hypoxia is common after dialysis and is most significant in the period immediately post-dialysis.
Possible causes include:
• Intrapulmonary leukostasis due to compliment activation
• Microatelectasis
• Increased pH (Bohr effect)
• Metabolism of small amounts of acetate (4mmol/l) in bicarbonate dialysate can lead to a loss of carbon dioxide, under ventilation and hence hypoxia
