Best Practice

Question 1

net positive fluid balance manifests as

Answer 1

interstitial oedema

Question 2

triad for intra-vascular fluid depletion

Answer 2

tachycardia, drop in blood pressure, a postural fall in blood pressure.

Question 3

NICE signs for hypovolaemia and urgent fluid resus

Answer 3

Systolic blood pressure below 100 mmHg
Heart rate above 90 beats per minute
Capillary refill time is longer than 2 seconds, or peripheries are cold to the touch
Respiratory rate is above 20 breaths per minute
National Early Warning Score (NEWS) is 5 or more
Passive leg raising suggests fluid responsiveness.

Question 4

signs of fluid overload

Answer 4

elevated JVP, third heart sound, bibasal crepitations, dependent oedema, hypertension

Question 5

volume responsiveness refers too

Answer 5

giving additional fluid will increase preload and cause a significant increase in stroke volume. This augments cardiac output and therefore perfusion and oxygen delivery.

Question 6

limitations of fluid balance charts

Answer 6

don’t take account of insensible loss, oral water inaccurately recorded or urinal volume incompletely measured.

Question 7

biochemical signs of dehydration or cardiac failure

Answer 7

urea is usually disproportionately raised when compared to creatinine.

Question 8

reduced renal perfusion affects urine by

Answer 8

reducing volume of concentrated urine with low sodium excretion

Question 9

An IVC collapse of below 12mm in a spontaneously breathing patient indicates

Answer 9

hypovolaemia

Question 10

signs of preload responsiveness

Answer 10

sub aortic peak velocities, aortic blood flow, pulse contour analysis, respiratory variations of the IVC and SVC, passive leg raising.

Question 11

NICE suggests the use of what for routine maintenance alone?

Answer 11

dextrose saline (0.18% sodium chloride with 4% glucose) with 27 mmol/l potassium added.

Question 12

hypotensive urgent fluid resus NICE recommends

Answer 12

administer 500 ml of a crystalloid with a sodium content of 130 mmol/l to 154 mmol/l over less than 15 minutes.

Question 13

what percentage of crystalloids end up in the interstitium

Answer 13

80%

Question 14

hypovolaemic haemorrhagic shock NICE recommends

Answer 14

blood products

Question 15

recovery from acute tubular necrosis is characterised by a

Answer 15

polyuric phase of several litres of diluted urine each day.

Question 16

What urinary biochemistry would suggest persistent hypovolaemia rather than established acute renal failure?

1) Urine sodium 5 mmol/l
2) Urine osmolality 320 mmol/l
3) Urine specific gravity below 1010
4) Urine urea 84 mmol/l

Answer 16

1)Urine sodium 5 mmol/l

Question 17

A patient presents with nephrotic syndrome:

Oedema
Proteinuria 5 g/24 hr
Reduced serum albumin.

Which one of the following would be an appropriate part of your management plan?

1) Saline infusion to replace intravascular depletion
2) 20% albumin infusion to correct hypoalbuminaemia
3) Low sodium diet
4) High protein intake

Answer 17

3) low sodium diet

Question 18

if pH is below 7.35 and PCO2 is increased then there is

Answer 18

primary respiratory acidosis

Question 19

if pH is below 7.35 and HCO3- is decreased then there is

Answer 19

primary metabolic acidosis

Question 20

if pH is above 7.45 and POC2 is decreased it is

Answer 20

primary respiratory alkalosis

Question 21

if pH is above 7.45 and HCO3- is increased it is

Answer 21

primary metabolic alkalosis.

Question 22

anion gap formula is

Answer 22

Na+ - (HCO3- + Cl-)

Question 23

the normal anion gap is

Answer 23

8-16mmol/l.

Question 24

three main causes of a high anion gap acidosis

Answer 24

increased endogenous acid production.

increased exogenous acids.

inability to excrete acid.

i.e. increase in unmeasured anions - hydrogen ions reacting with bicarbonate ions.

Question 25

two main causes of a normal anion gap acidosis

Answer 25

loss of bicarbonate, impaired renal excretion.

I.e. lost bicarbonate ions are replaced with chloride ions.

Question 26

effect of low albumin on anion gaps

Answer 26

low albumin may have a normal anion gap in the presence of a disorder that produces a high anion gap.

Question 27

respiratory acidosis metabolic compensation is

Answer 27

renal excretion of carbonic acid and re-absorption of bicarbonate is increased

Question 28

in respiratory alkalosis metabolic compensation is

Answer 28

kidneys reduce reabsorption of bicarbonate and excretion of ammonium.

Question 29

consider a mixed acid base disorder when

Answer 29

compensation is inadequate or excessive.

PCO2 and HCO3- concentrations become abnormal in opposite directions.

pH is normal but PCO2 or HCO3 concentration is abnormal (normal compensations rarely return pH to normal)

Question 30

When the pCO2 is elevated and the HCO3- concentration is reduced =

Answer 30

respiratory acidosis and metabolic acidosis coexist

Question 31

When the pCO2 is reduced and the HCO3- concentration is elevated

Answer 31

respiratory alkalosis and metabolic alkalosis coexist.

Question 32

the A-a gradient is

Answer 32

difference between the calculated alveolar pO2 and the measured arterial pO2

Question 33

A-a gradient calculation is

Answer 33

A-a gradient = alveolar pO2 - arterial pO2

Question 34

alveolar Po2 =

Answer 34

PiO2 - arterial pCO2 x 1.2

Pio2 = effective inspired pO2

Question 35

main causes of respiratory acidosis

Answer 35

depression of respiratory drive
neuromuscular weakness
chest wall abnormality
disorder affecting gas exchange (COPD, asthma etc)
Airway obstruction.

Question 36

main causes of respiratory alkalosis

Answer 36

CNS stimulation (head trauma, hyperventilation, tumour)
Hypoxia (anaemia, high altitude)
Pulmonary disease
Drugs (Salicylates, aminophyllines)

Question 37

main causes of metabolic alkalosis

Answer 37

hydrogen ion loss (Renal or GI)
intracellular shift of hydrogen (Hypokalaemia) 
contraction alkalosis (Diuretics)

Question 38

the axis is normal if the QRS complex is predominantly upwards in leads

Answer 38

1 and 2

Question 39

left axis deviation occurs when the QRS complex is predominantly upwards in lead and downward in lead

Answer 39

upward lead 1 and downward lead 2

Question 40

right axis deviation occurs when the QRS complex is predominantly downward in lead and upward in lead

Answer 40

downward lead 1 and upward lead 2