Read the pH: below 7.35 is acidosis, above 7.45 alkalosis.
Find the value that explains it: PaCO₂ moving opposite to the pH is respiratory, HCO₃⁻ moving with the pH is metabolic.
Look at the other value: normal means uncompensated, abnormal in the compensating direction means partial compensation, and a normal pH with both abnormal means full compensation.
In a metabolic acidosis, compare PaCO₂ with Winter’s formula, 1.5·HCO₃⁻ + 8 ± 2, and calculate the anion gap Na⁺ − (Cl⁻ + HCO₃⁻).
Check a high anion gap with the delta ratio and, when albumin is low, with the corrected gap.
Nursing math & unit conversions
Metric steps
1 kg = 1000 g, 1 g = 1000 mg, 1 mg = 1000 mcg, 1 L = 1000 mL
Weight and length
1 kg = 2.2 lb, 1 lb = 16 oz, 1 in = 2.54 cm, 1 ft = 12 in
Household measures
1 tsp = 5 mL, 1 tbsp = 15 mL, 1 fl oz = 30 mL, 1 cup = 8 fl oz = 240 mL
Write the given quantity with its unit and the unit you want.
Pick the equivalent: 1000 between kg, g, mg and mcg or L and mL; 1 kg = 2.2 lb; 1 tsp = 5 mL, 1 tbsp = 15 mL, 1 fl oz = 30 mL, 1 cup = 240 mL.
Write it as a fraction so that the unwanted unit cancels; for a rate, use one fraction per unit that changes.
Check the direction: a smaller unit gives a bigger number.
Round only the final answer, to the precision the question names.
2Practice problems
1.Clinical assessment scoresMedium
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 30/min, SpO₂ 96% on room air, blood pressure 118/70 mmHg, pulse 114/min, alert, temperature 38.0 °C. What is the NEWS2 total score?
RR 30SpO₂ 96%airSBP 118HR 114AT 38.0 °C
NEWS2 =
2.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 22/min, SpO₂ 98% on room air, blood pressure 142/86 mmHg, pulse 76/min, alert, temperature 35.2 °C. Which clinical risk group does the patient fall into? Click it.
RR 22SpO₂ 98%airSBP 142HR 76AT 35.2 °C
1low
2low–medium
3medium
4high
3.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.38, PaCO₂ 21 mmHg (2.8 kPa) and HCO₃⁻ 12 mmol/L. The primary disorder is metabolic acidosis. How far is it compensated? Click your answer.
pH 7.38PaCO₂ 21 mmHg (2.8 kPa)HCO₃⁻ 12 mmol/L
1uncompensated
2partially compensated
3fully compensated
4.Arterial blood gas interpretationHard
A practice gas shows a respiratory acidosis: pH 7.32, PaCO₂ 73 mmHg (9.7 kPa), HCO₃⁻ 36 mmol/L. Use the rules ‘HCO₃⁻ rises 1 mmol/L per 10 mmHg (acute) or 3.5 mmol/L per 10 mmHg (chronic)’ to classify it. Click your answer.
pH 7.32PaCO₂ 73 mmHg (9.7 kPa)HCO₃⁻ 36 mmol/L
1acute
2chronic
3acute on chronic
5.Nursing fundamentalsMedium
When are non-sterile gloves needed?
AFor every patient contact, including taking a pulse or blood pressure
BOnly when handling medicines
CWhen contact with blood, body fluids or broken skin is expected
DOnly when the patient is known to have an infection
6.Nursing fundamentalsHard
In early hypovolaemic shock in a young adult, which sign usually appears before blood pressure falls?
AA slow heart rate
BA very low blood pressure
CA rising heart rate with cool peripheries
DWarm, flushed skin
7.Nursing math & unit conversionsMedium
Practice exercise (made-up values, not clinical guidance). A patient’s temperature is 103.7 °F. Convert it to degrees Celsius T with °C = (°F − 32) × 5/9. Round to one decimal place.
103.7 °F
T = °C
8.Nursing math & unit conversionsHard
Practice exercise (made-up values, not clinical guidance). A maintenance infusion runs at 80 mL/h without a break. How many litres V does it deliver in 24 hours?
80 mL/h24 h
V = L
3Solutions
1.Clinical assessment scores
Answer: NEWS2 = 5
NEWS2 (National Early Warning Score 2, Royal College of Physicians 2017): score each of the seven parameters with the chart (respiration rate, SpO₂ on scale 1, air or supplemental oxygen, systolic blood pressure, pulse, consciousness on the ACVPU scale and temperature) and add the scores. Clinical risk: 0–4 low; a score of 3 in any single parameter low–medium; 5–6 medium; 7 or more high. A total of 5 or more needs an urgent response.
Score each parameter
RR 30/min → 3
SpO₂ 96% → 0
on air → 0
SBP 118 mmHg → 0
HR 114/min → 2
alert (A) → 0
T 38.0 °C → 0
Add
NEWS2 = 3 + 0 + 0 + 0 + 2 + 0 + 0 = 5
Answer
NEWS2 = 5
2.Clinical assessment scores
Answer: low
NEWS2 (National Early Warning Score 2, Royal College of Physicians 2017): score each of the seven parameters with the chart (respiration rate, SpO₂ on scale 1, air or supplemental oxygen, systolic blood pressure, pulse, consciousness on the ACVPU scale and temperature) and add the scores. Clinical risk: 0–4 low; a score of 3 in any single parameter low–medium; 5–6 medium; 7 or more high. A total of 5 or more needs an urgent response.
Score each parameter
RR 22/min → 2
SpO₂ 98% → 0
on air → 0
SBP 142 mmHg → 0
HR 76/min → 0
alert (A) → 0
T 35.2 °C → 1
Total and red scores
NEWS2 = 2 + 0 + 0 + 0 + 0 + 0 + 1 = 3
No parameter scores 3.
Risk group
low
Answer
low
3.Arterial blood gas interpretation
Answer: fully compensated
Reading a blood gas (ROME): first the pH: below 7.35 is acidaemia, above 7.45 alkalaemia. Then find the value that explains it. PaCO₂ (normal 35–45 mmHg, 4.7–6.0 kPa) is the respiratory part and moves Opposite to the pH in a respiratory disorder; HCO₃⁻ (normal 22–26 mmol/L) is the metabolic part and moves in the same direction as the pH (Respiratory Opposite, Metabolic Equal). The other value shows the compensation: normal means uncompensated; abnormal in the direction that pulls the pH back while the pH is still abnormal means partially compensated; a normal pH with both values abnormal means fully compensated. Ranges differ slightly between laboratories; these are practice values.
ROME, value by value
pH 7.38: within 7.35–7.45
PaCO₂ 21 mmHg: low (35–45)
HCO₃⁻ 12 mmol/L: low (22–26)
Compensation
Clinically, also check the expected compensation: Winter’s formula expects PaCO₂ 24–28 mmHg, so the measured 21 mmHg points to an additional respiratory alkalosis (a mixed disorder). The answer above is the ROME exam classification.
fully compensated
Answer
fully compensated
4.Arterial blood gas interpretation
Answer: chronic
Expected compensation: in metabolic acidosis Winter’s formula predicts PaCO₂ = 1.5·HCO₃⁻ + 8 ± 2 mmHg; a measured value above that range points to an additional respiratory acidosis, below it to an additional respiratory alkalosis. The anion gap AG = Na⁺ − (Cl⁻ + HCO₃⁻), normally about 8–12 mmol/L, separates high-gap from normal-gap metabolic acidosis; low albumin hides a high gap (add 2.5 per g/dL that albumin is below 4.0). The delta ratio (AG − 12)/(24 − HCO₃⁻) between about 0.8 and 2 fits a pure high-gap acidosis (some texts use 1 instead of 0.8), below that an added normal-gap acidosis, and above 2 an added metabolic alkalosis.
Expected HCO₃⁻
acute: 24 + 1·3.3 = 27.3 mmol/L
chronic: 24 + 3.5·3.3 = 35.55 mmol/L
Compare
measured: 36 mmol/L → chronic
Answer
chronic
5.Nursing fundamentals
Answer: C · When contact with blood, body fluids or broken skin is expected
Why this is the answer
Under standard precautions, gloves are worn when exposure to blood or body fluids is likely. Wearing them for all contact gives false security and can spread germs if not changed.
Answer
C · When contact with blood, body fluids or broken skin is expected
6.Nursing fundamentals
Answer: C · A rising heart rate with cool peripheries
Why this is the answer
Compensation through tachycardia and vasoconstriction keeps blood pressure normal at first, so low blood pressure is a late sign. Tachycardia, cool skin and slow capillary refill should prompt action.
Answer
C · A rising heart rate with cool peripheries
7.Nursing math & unit conversions
Answer: T = 39.8 °C
Temperature: °C = (°F − 32) × 5/9 and °F = °C × 9/5 + 32. Subtract 32 before you multiply when going from °F, and add 32 after you multiply when going from °C. A quick check: 37 °C is 98.6 °F, and every 1 °C is 1.8 °F.
Subtract 32
103.7 − 32 = 71.7
Multiply by 5/9
T = 71.7·5/9 = 39.83 ≈ 39.8 °C
Answer
T = 39.8 °C
8.Nursing math & unit conversions
Answer: V = 1.92 L
Dimensional analysis: write the given quantity, then multiply by conversion factors written as fractions (for example 60 min/1 h or 1 mg/1000 mcg) so that each unwanted unit appears once on top and once underneath and cancels. When only the wanted unit is left, calculate. Use the equivalents the question gives and round only the final answer.