Sommar 2022

Question 1

In spinal cord injury, are the following statements true or false?

True / False

Hemisection of the spinal cord results in ipsilateral paralysis below the level of the lesion?

Answer 1

True

Explanation: motorneuron kopplar om i medulla (pyramidal decussation)

Injury to the anterior spinal cord results in paralysis (motor loss) below the level of the lesion, with proprioception, touch and vibration senses being preserved.

Hemisection of the cord (Brown-Sequard syndrome) results in ipsilateral paralysis and loss of proprioception, touch and vibration sense, together with loss of pain and temperature sensation on the contralateral side.

Question 2

In spinal cord injury, are the following statements true or false?

True / False

Hemisection of the spinal cord results in loss of contralateral proprioception below the level of the lesion?

Answer 2

False

Explanation: proprioception, vibration och sensorik korsar över i medulla oblongata

Injury to the anterior spinal cord results in paralysis (motor loss) below the level of the lesion, with proprioception, touch and vibration senses being preserved.

Hemisection of the cord (Brown-Sequard syndrome) results in ipsilateral paralysis and loss of proprioception, touch and vibration sense, together with loss of pain and temperature sensation on the contralateral side.

Question 3

In spinal cord injury, are the following statements true or false?

True / False

Hemisection of the spinal cord results in loss of ipsilateral pain sensation below the level of the lesion?

Answer 3

False

Explanation: smärtsensorik och temperatur korsar över segmentellt i ryggmärgen, precis efter omkoppling till andra gradens neuron och fortlöper sen kontralateralt och ventralt upp

Injury to the anterior spinal cord results in paralysis (motor loss) below the level of the lesion, with proprioception, touch and vibration senses being preserved.

Hemisection of the cord (Brown-Sequard syndrome) results in ipsilateral paralysis and loss of proprioception, touch and vibration sense, together with loss of pain and temperature sensation on the contralateral side.

Question 4

In spinal cord injury, are the following statements true or false?

True / False

Section of the anterior cord results in impaired proprioception, touch and vibration sense below the level of the lesion?

Answer 4

False

Explanation: ytlig beröring, proprioception och vibration kopplar om i dorsalhornet och fortlöper ipsilateralt dorsalt upp till medulla där de korsar över, temperatur och smärta kopplar om i dorsalhornet men fortlöper sen kontralateralt och anteriort upp till thalamus

Injury to the anterior spinal cord results in paralysis (motor loss) below the level of the lesion, with proprioception, touch and vibration senses being preserved.

Hemisection of the cord (Brown-Sequard syndrome) results in ipsilateral paralysis and loss of proprioception, touch and vibration sense, together with loss of pain and temperature sensation on the contralateral side.

Question 5

In spinal cord injury, are the following statements true or false?

True / False

Section of the anterior cord results in paralysis below the level of the lesion?

Answer 5

True

Explanation: motoriska neuron kopplar om ventralt och fortlöper ipsilateralt ventralt upp till hjärnan

Injury to the anterior spinal cord results in paralysis (motor loss) below the level of the lesion, with proprioception, touch and vibration senses being preserved.

Hemisection of the cord (Brown-Sequard syndrome) results in ipsilateral paralysis and loss of proprioception, touch and vibration sense, together with loss of pain and temperature sensation on the contralateral side.

Question 6

Are the following statements concerning intravenous fluids true?

True / False

0.9% saline solution has a similar pH to plasma?

Answer 6

False

Explanation: 0.9% saline has a pH of 5.5, whereas plasma pH is approximately 7.4

Question 7

Are the following statements concerning intravenous fluids true?

True / False

Colloids, generally, have lower sodium concentrations than 0.9% saline?

Answer 7

False

Explanation: Artificial colloids are suspensions of large molecules in 0.9% saline and so contain 154 mmol per litre of sodium (the same).

Question 8

Are the following statements concerning intravenous fluids true?

True / False

Hartmann’s solution has a higher chloride concentration than 0.9% saline

Answer 8

False

Explanation: Hartmann’s solution contains:

131 mmol per litre of sodium ions
111 mmol per litre of chloride ions
2 mmol per litre of calcium ions
5 mmol per litre of potassium ions and
29 mmol per litre of lactate ions.

It therefore has a lower chloride concentration than 0.9% saline (154 mmol per litre of sodium and chloride ions).

Question 9

Are the following statements concerning intravenous fluids true?

True / False

Hydroxyethyl starch solutions do not interfere with blood cross-matching?

Answer 9

True

Explanation: Hydroxyethyl starch solutions do not interfere with blood cross-matching, unlike the dextrans, although rouleaux formation may occur.

Rouleaux formation: happens when either fibrinogens or globulins are present at high levels in the blood, although at times it may be caused by incorrect blood smear preparation when blood is placed on a slide for microscopic examination. The formation causes red blood cells to be stacked on top of each other.

Question 10

Are the following statements concerning intravenous fluids true?

True / False

Pruritus is associated with the use of hydroxyethyl starch solutions?

Answer 10

True

Explanation: The hydroxyethyl starches are removed from the circulation by the reticuloendothelial system and are deposited in the skin. Pruritus is therefore a relatively common and significant sequel of over-enthusiastic administration of starches.

Question 11

Which of the following reduce protein catabolism?

Cortisol
Glutamine
Growth hormone
Insulin
Insulin-like growth factor-1

Answer 11

Which of the following reduce protein catabolism:

Glutamine: is used to reduce catabolism in critically ill patients.

Growth hormone: promotes protein synthesis and inhibits protein catabolism.

Insulin: inhibits protein catabolism and lipolysis.

Insulin-like growth factor-1: GH also stimulates hepatic production of insulin-like growth factor-1 which has the same effect on protein synthesis and catabolism.

*Cortisol stimulates protein catabolism.

Question 12

Do the following enzymes synthesise the neurotransmitters with which they are paired?

1) Catechol-O-methyl transferase (COMT) and dopamine?
2) Catechol-O-methyl transferase (COMT) and norepinephrine?
3) Cholinesterase and acetylcholine?
4) Glutamic acid decarboxylase and gamma-aminobutyric acid (GABA)?
5) Monoamine oxidase and serotonin?

Answer 12

1) False - COMT metaboliserar dopamin till 3-methoxytyramine, samt noradrenalin och adrenalin till normetaephrine resp. metanephrine
2) False - COMT metaboliserar NA
3) False - Cholinesteras metaboliserar ACh
4) True - Glutamic acid decarboxylase does synthesise gamma-aminobutyric acid (GABA).
5) Falsk - MAO metaboliserar serotonin till 5-hydroxyindole acetic acid (5-HIAA)

Question 13

Hypokalaemia is associated with which the following?

Insulin infusions
Oral furosemide therapy
Prednisolone therapy
Salbutamol nebuliser therapy
Spironolactone therapy

Answer 13

Hypokalaemia is associated with which the following?

Insulin infusions: true 
Oral furosemide therapy: true 
Prednisolone therapy: true 
Salbutamol nebuliser therapy: true 
Spironolactone therapy: false 

Explanation:
Hypokalaemia is associated with insulin therapy due to the effect of insulin on the cell membrane sodium-potassium pump causing intracellular shift of potassium.

Nebulised salbutamol is a recognised treatment for hyperkalaemia.

Prednisolone is capable of producing hypokalaemia due to excessive potassium excretion.

Conversely Addison’s is associated with hyperkalaemia.

Spironolactone is associated with potassium retention.

Thiazide and loop diuretics are both associated with hypokalaemia.

Question 14

A previously fit 23-year-old is having a general anaesthetic for an inguinal hernia repair. He is breathing spontaneously with a supraglottic airway being maintained with air/oxygen and sevoflurane via a circle system.

The end-tidal CO2 reads 8.1 kPa with a fresh gas flow of 14 L/min. Inspired CO2 is 1.9 kPa. Inspired and the expired oxygen are 38 and 33 % respectively.

What is the most likely cause for these readings?

a) Exhaustion of soda lime
b) Incompetent expiratory valve
c) Leak in the expiratory limb
d) Onset of malignant hyperthermia
e) Upper airway obstruction

Answer 14

What is the most likely cause for these readings?

Svar: The two most likely causes of rebreathing are exhaustion of the soda lime and failure of the expiratory valve.

*Om exp valve har fastnat i ett öppet läge kommer man återandas utandad luft.

Explanation: The patient is rebreathing expired carbon dioxide.

The two most likely causes are exhaustion of the soda lime and failure of the expiratory valve. A less likely cause is a leak in the inspiratory limb. If the expiratory valve is incompetent, increased inhaled and exhaled carbon dioxide levels may appear with a normal appearing capnogram.

If the inspiratory valve is incompetent the patient will exhale into both the inspiratory and expiratory limbs. The capnogram sometimes shows a characteristic slanted downstroke inspiratory phase (as the patient inhales carbon dioxide-containing gas from the inspiratory limb) and increased end-tidal carbon dioxide.

With a high fresh gas flow, even if the soda lime were exhausted it would be sufficient to prevent rebreathing. The difference in inspired and expired oxygen concentrations would not be as marked.

Respiratory obstruction and malignant hyperthermia are causes of hypercapnia but not rebreathing.

Question 15

Helium:

True / False

1) Combined with oxygen can reduce the work of breathing in patients with upper airway obstruction?
2) Combined with oxygen is supplied in brown cylinders
3) Has a higher density than oxygen
4) Is a noble gas
5) Is the most abundant element in the universe

Answer 15

Helium: is a noble gas used in the measurement of lung volumes and to improve airflow in patients with upper airway resistance

1) Combined with oxygen can reduce the work of breathing in patients with upper airway obstruction? - True
2) Combined with oxygen is supplied in brown cylinders - False
3) Has a higher density than oxygen - False
4) Is a noble gas - True
5) Is the most abundant element in the universe - False

Explanation: Helium is a light inert gas and is the second most abundant element in the universe, after hydrogen. It has an atomic number of 2 and heads the group of noble gases in the periodic table.

Helium is present in air and in natural gas from which it is extracted. It is supplied at 137 bar as either heliox (79% He, 21% O2) in white cylinders with white/brown shoulders or as 100% helium in brown cylinders.

Helium has a lower density (and hence specific gravity) than oxygen, nitrogen and air. Therefore, for a given pressure difference, laminar flow is better preserved and provides better airflow. This has the potential to reduce the work of breathing in patients with upper airway obstruction (i.e. tumour, epiglottitis). Its use in severe asthma and chronic obstructive airway disease has also been suggested. Helium/oxygen mixtures are also used for deep water diving to avoid nitrogen narcosis.

Helium is used in the measurement of lung volumes because of its very low solubility.

The lower density of helium/oxygen mixture produces the typical squeaky voice due to the higher frequency vocal sounds.

Question 16

A transport ventilator is connected to a size CD oxygen cylinder. With a setting of air/oxygen mix (entrainment ratio 1:1) and a minute volume set at 10 litres/minute.

Which of the following values best approximates to the FiO2?

0. 4
1. 5
2. 6
3. 8
4. 0

Answer 16

0,6

The CD cylinder has a nominal volume of 2 litres. When full it has a pressure of 230 bar. It contains litres 460 L of useable oxygen at STP (standard temoperature and pressure).

With an air/oxygen mix, for every 1000 mL 100% oxygen there will be an entrainment of 1000 mL or air (20% oxygen, 200 ml oxygen). Total oxygen content 1200 ml per 2000 ml mixture. 1200/200 = 0,6.

The average concentration is, therefore, 120/2=60% or FiO2 0.6

Question 17

Which of the following are secreted from the posterior pituitary?
IGF-1?

Oestradiol
Oxytocin
Progesterone
Prolactin

Answer 17

Manufactured in the hypothalamic nuclei, antidiuretic hormone (ADH) and oxytocin are secreted from the posterior pituitary.

IGF-1 is mostly produced under the influence of growth hormone by the liver.

Question 18

In a normal adult woman weighing 60 kg which of the following is true about the extracellular fluid (ECF)?

a) Contains no protein
b) Forms a greater proportion of the total body weight in the obese than in the lean woman
c) Has a sodium concentration of 125-135 mmol/L
d) Has a total volume of about 12 litres
e) Is isotonic throughout the bod

Answer 18

d) Has a total volume of about 12 litres

Total body water is about 60% of body weight (50% to 70% depending on how much fat is present). In the obese ECF is relatively contracted.

Total body water is about 60% of body weight (50% to 70% depending on how much fat is present). In the obese ECF is relatively contracted.

In this person total body water is approximately 36 litres (0.6 × 60), of which 1/3 is ECF (12 litres) and 2/3 (24 litres) intracellular fluid.

The simple rule is 60-40-20.

Normal sodium concentration is approximately 135-145 mmol/L.

ECF is composed of intravascular fluid and extravascular fluid. Both contain plasma proteins.

Question 19

A 2-year-old child presents for inguinal hernia repair. A caudal anaesthetic block is planned for this procedure.

Which one of the following options best explains why access to the caudal epidural space is via the sacral hiatus?

a) The dural sac ends at the level of the sacral hiatus
b) The failure of fusion of the laminae of S4 and S5 provides a suitable point of entry
c) The posterior superior iliac spines and sacral hiatus form an equilateral triangle pointing downwards
d) The sacral hiatus is palpable only in the lateral position
e) The sacrococcygeal membrane is tough and offers noticeable resistance

Answer 19

b) The failure of fusion of the laminae of S4 and S5 provides a suitable point of entry

The sacral canal results from the fusion of the laminae of the five sacral vertebrae in the midline. Failure of fusion of the S4 and S5 results in the formation of the sacral hiatus. The sacral hiatus is easily identifiable as a small depression between the sacral cornua, hence making the performance of the sacral block possible with the use of landmarks.

The posterior superior iliac spines and sacral hiatus form an equilateral triangle pointing downwards and can be felt in the lateral and prone positions.

The dural sac ends at the level of S2 in adults and S3 in children.

Question 20

Are the following statements true regarding randomised controlled trials in single patients (n of 1 trials)?

a) Are inappropriate for drugs with longlasting effect
b) Are useful where the patient doubts the effectiveness of a treatment
c) Can guide treatment in other patients
d) Have an advantage in studying drugs with long half lives
e) Need to be repeated in many patients to achieve significant results

Answer 20

a) Are inappropriate for drugs with longlasting effect - True
b) Are useful where the patient doubts the effectiveness of a treatment - True
c) Can guide treatment in other patients - False
d) Have an advantage in studying drugs with long half lives - False
e) Need to be repeated in many patients to achieve significant results - False

In an ‘n of 1’ trial the treatment and placebo are given at random treatment periods to the same patient.

The results are specific to one drug and the patient studied and cannot usually be generalised.

They are useful where the patient doubts the effectiveness of a treatment or where the practitioner has doubts. They are also useful for dosing or working out if a symptom is a side effect or not.

Drugs with short lived effects are best, as long wash-out periods need to be included for long acting drugs.

Question 21

May the depth of anaesthesia be monitored using the following?

1) The isolated forearm technique?
2) Lower oesophageal contractility?
3) Ocular microtremor?
4) Skin conductivity?
5) R-R beat variability.

Answer 21

Alla

Monitoring the depth of anaesthesia and methods for detecting awareness during anaesthesia are numerous and include:

The isolated forearm technique
Lower oesophageal contractility
Ocular microtremor
Skin conductivity and
R-R beat variability.
Clinical signs have been used to detect lightening of anaesthetic depth but these are unreliable.

The presence of hypertension, tachycardia, sweating and lacrimation or PRST (that is, pressure rate sweat and tears) are worrying signs.

Other methods to assess the depth of anaesthesia include:

Digital plethysmography
Electromuscular monitoring
Electroencephalogram and cerebral function monitoring
Evoked potentials.

Question 22

Typical changes in pulmonary function during a moderate asthma attack include the following?

1) Decreased forced expiratory volume in 1 sec (FEV1)
2) Decreased functional residual capacity (FRC)
3) Increased arterial pO2
4) Increased arterial pCO2
4) Raised serum bicarbonate concentration

Answer 22

In mild to moderate asthma attacks the arterial pCO2 may decrease. With increasing severity the pCO2 returns to normal and in severe asthma attacks it may be increased.

With airways obstruction the functional residual capacity increases (not decreases).

The serum bicarbonate concentration would not be raised in moderately severe asthma but it could be in a life-threatening attack for the same reasons as the arterial PCO2 increases.

The forced expiratory volume in 1 sec (FEV1) is a good indication of airway obstruction.

Do not be confused with chronic obstructive pulmonary disease (COPD) where reduced FEV1 is normally mentioned. It measures airways obstruction and is reduced in acute asthma.

The arterial pO2 is usually normal in a moderate attack but may decrease during a severe asthma attack.

If a pneumothorax occurs then the fall in arterial PO2 may be greater.

Question 23

Which one of the following is characteristic of the physiological responses to starvation and the stress response to surgery?

Fatty acids are converted to glucose?

Increase in basal metabolic rate?

Reduced insulin production?

Reversal of process by feeding?

Renin angiotensin system activation?

Answer 23

The stress response results in reduced insulin production and often a rise in blood glucose accompanies this.

Explanation:

Fatty acids cannot be converted to glucose, so this option is incorrect. This is because acetyl-CoA (formed from β-oxidation of fatty acids) cannot be converted to pyruvate and therefore the only other source of glucose is amino acids derived from protein breakdown.

Increase in basal metabolic rate is incorrect as starvation reduces the basal metabolic rate (BMR), whereas the stress response results in rises in BMR, body temperature and O2 consumption.

Reduced insulin production is the correct response here. Starvation results in reduced insulin production in response to hypoglycaemia. The stress response results in reduced insulin production and often a rise in blood glucose accompanies this.

Reversal of process by feeding is incorrect as feeding does not attenuate the stress response but does immediately reverse the process of starvation.

Renin angiotensin system activation is incorrect as the sympathetic nervous system and RAS are only activated in the stress response.

The stress response and the physiology of starvation are both catabolic processes but there are important differences between them.

Question 24

72-year-old man complains of numbness in his feet and difficulty walking. On examination he has normal pain and temperature sensation in his lower limbs, but decreased appreciation of light touch and proprioception.

Which of the following is the most likely site of a neurological lesion?

a) Lamina II of dorsal horn grey matter?
b) Lateral corticospinal tracts?
c) Lateral spinothalamic tracts?
d) Spinocerebellar tracts?
e) Dorsal columns?

Answer 24

e) Dorsal columns

Explanation

The dorsal (posterior) columns are ascending pathways that carry information regarding light touch and proprioception.

The grey matter of the spinal cord is divided into three columns (anterior horn, posterior horn and the grey commissure), and on transverse section is butterfly shaped. The dorsal (posterior) horn is divided into the laminae of Rexed and the primary afferent sensory neurones synapse prior to relay.

The laminae identified are:

I (marginal posteromarginal) receives Aδ fibres and are involved with fast pain and temperature sensation.
II (substantia gelatinosa) receives C fibres and are involved with slow pain sensation.
Laminae III and IV (nucleus proprius), receives inputs from the dorsal root ganglia and carry sensory information such as light touch, pain and temperature sensation.
Lamina V (neck of dorsal horn) receives fine afferents from the skin, muscles and viscera.
Lamina VI (base of dorsal horn) receives proprioceptive fibres and contributes to the pathway for the deep tendon reflex.
The primary neurones of the lateral corticospinal tract originate in the motor cortex. A lesion in the primary motor cortex or in the tract would result in disorders of motor function.
The lateral spinothalamic tract is an ascending sensory pathway from the periphery to the thalamus. The first order neurones carry information regarding pain, temperature, coarse touch and pressure.
The anterior and posterior spinocerebellar tracts convey proprioceptive and cutaneous sensation from Golgi tendon organs and muscle spindles to the cerebellum for the coordination of movement.

Question 25

Which of the following electromagnetic waves have the shortest wavelength?

a) Infrared?
b) Radio waves?
c) UV?
d) Visible light?
e) X-rays?

Answer 25

e) X-rays

X rays have a very small wavelength with a range of 0.01-10 nm.

Infrared radiation (IR) has wavelengths between 1 mm and 750 nm. The smallest wavelengths nearest to the visible spectrum are termed “near-infrared” and the largest wavelengths “far-infrared”. Infrared absorption spectroscopy is used for volatile agent monitoring. Wavelengths of 3.3 μm are used because all current volatile agents have a strong absorption peak at this wavelength. Volatile anaesthetic agents also absorb at wavelengths of 9 and 12 μm.

Carbon dioxide absorbs infrared light at the far end at 4.3 μm and is used in capnography.

Pulse oximetry works using spectrophotometry. The two wavelengths of light used are visible red light at a wavelength of 660 nm and near infrared light at a wavelength of 940 nm.

Visible light has a wavelength range between 400 nm and 700 nm.

Ultraviolet light (UV) has a wavelength range between 100 nm and 400 nm. Volatile anaesthetic monitoring can utilise UV light absorption techniques.

Radio waves have the largest wavelength at between 100 mm and 10 000 km.

Gamma “rays” have the smallest wavelength of the electromagnetic spectrum. They are used commercially to sterilise surgical instruments and anaesthetic equipment. The wavelength range less than 10 pm.

Question 26

In hypothermia, are the following statements true or false?

a) A metabolic acidosis is a common finding?
b) Hypertension is often seen during rewarming?
c) Pancreatitis is a recognised complication? d) Passive rewarming is advised for all patients?
e) The oxygen dissociation curve is shifted to the left?

Answer 26

True:

a) A metabolic acidosis is a common finding
c) Pancreatitis is a recognised complication
e) The oxygen dissociation curve is shifted to the left

Explanation: 
Hypothermia is defined as a core temperature less than 35°C, and is associated with:
- Hypopituitarism
- Hypothyroidism
- Spinal cord trauma, and
- Alcohol and drug overdose.

In hypothermic patients the oxygen dissociation curve is shifted to the left.

A metabolic acidosis is commonly seen in hypothermia, and is exacerbated by a reduction in hepatic clearance and renal excretion of hydrogen ions and lactic acid.

Other complications include:

• Acute pancreatitis
• Hyperglycaemia
• Thrombocytopenia, and
• A coagulopathy.

Passive rewarming is appropriate when the core temperature is above 33°C (not all patients), but active measures are required when the temperature is lower.

Hypotension may be seen as the core temperature rises, as hypovolaemia is revealed and will usually require fluid resuscitation.

Question 27

Boiling point of Desflurane at one atmosphere of pressure?

Answer 27

22,8 degrees Celsius