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.
Write down what is asked: a pump rate, a volume, kilocalories, grams of protein or water.
Turn energy into volume with mL = kcal/(kcal/mL), and volume into protein with litres × g/L.
Divide by the hours the feed actually runs for a rate, or by the number of feeds for a bolus.
For needs, multiply kcal/kg or g/kg by the weight the rule names; find the ideal body weight with Devine: 50 or 45.5 + 2.3 × (inches − 60).
For PN, find grams as % × mL/100, then use 3.4 kcal/g for dextrose, 4 kcal/g for amino acids and the stated kcal/mL for lipid.
ECG rhythm strip interpretation
Paper (25 mm/s, 10 mm/mV)
1 small box = 0.04 s, 1 large box = 0.20 s, 10 mm = 1 mV
Heart rate, regular rhythm
300 ÷ large boxes = 1500 ÷ small boxes = 60 ÷ RR (s)
Heart rate, irregular rhythm
QRS complexes in 6 s × 10
Normal PR interval
0.12–0.20 s
Normal QRS duration
< 0.12 s
QTc (Bazett)
QT/√RR
QTc (Fridericia)
QT/∛RR
QTc (Framingham)
QT + 154·(1 − RR)
Sinus rates
bradycardia < 60, normal 60–100, tachycardia > 100 /min
Escape rates
junctional 40–60, ventricular 20–40 /min
Fast rhythms
SVT 150–250 /min (narrow), VT > 100 /min (wide)
Method
Rate: for a regular rhythm divide 300 by the large boxes or 1500 by the small boxes between two R waves; for an irregular rhythm count the QRS complexes in 6 seconds and multiply by 10.
Rhythm: compare the R–R intervals. Equal is regular; a repeating pattern is regularly irregular; no pattern at all is irregularly irregular.
P waves: is there an upright P wave in lead II before every QRS, all alike? Look for fibrillatory or sawtooth waves, inverted P waves and P waves without a QRS.
PR interval: from the start of P to the start of the QRS, normally 0.12–0.20 s and constant. Watch whether it lengthens, stays fixed before a dropped beat, or varies at random.
QRS duration: below 0.12 s is narrow; 0.12 s or more is wide. Then name the rhythm, and for the QT use QTc = QT/√RR (Bazett) with times in seconds.
Prioritization & delegation
Method
Ask what will harm the patient soonest if nothing is done.
Apply ABC (C-A-B in cardiac arrest), then Maslow: physiological needs before safety, safety before psychological needs.
Compare the options: acute before chronic, unstable before stable, unexpected before expected, systemic before local, and check each finding against the patient’s baseline.
Assess before you act unless it is an emergency; then choose the step the others depend on.
For delegation, check the five rights: task, circumstance, person, directions and supervision. Assessment, teaching and evaluation stay with the RN.
Infection control & patient safety
Method
Start with standard precautions for every patient: hand hygiene, PPE for the expected exposure, safe sharps.
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 22/min, SpO₂ 97% on room air, blood pressure 110/66 mmHg, pulse 58/min, alert, temperature 39.6 °C. What is the NEWS2 total score?
RR 22SpO₂ 97%airSBP 110HR 58AT 39.6 °C
NEWS2 =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 12/min, SpO₂ 86% on room air, blood pressure 222/134 mmHg, pulse 88/min, alert, temperature 36.9 °C. Which clinical risk group does the patient fall into? Click it.
Practice exercise (made-up values, not clinical guidance). A 51 kg patient needs 1.3 g of protein per kg a day. The tube feed contains 44 g of protein per litre and runs at 45 mL/h for 16 hours a day. How many grams of extra protein ΔP a day are still needed? Round to one decimal place.
Practice exercise (made-up values, not clinical guidance). Over 24 hours a patient receives 1200 mL of parenteral nutrition with final concentrations of 20% dextrose and 4% amino acids, plus 250 mL of 10% lipid emulsion (1.1 kcal/mL). Find the non-protein kilocalorie to nitrogen ratio NPC : N (the number x in x : 1). Round to the nearest whole number.
1200 mLdextrose 20%amino acids 4%lipid 250 mL · 1.1 kcal/mL
NPC : N =
11.ECG rhythm strip interpretationMedium
Measure the QT interval and the R–R interval on this regular lead II strip, then calculate the rate-corrected QTc with Bazett’s formula QTc = QT/√RR (both in seconds). Give the answer in seconds to three decimals.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
QTc = s
12.ECG rhythm strip interpretationHard
Identify the rhythm on this lead II strip. Click your answer.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
1ventricular fibrillation
2torsades de pointes
3supraventricular tachycardia (SVT)
4atrial flutter, 2:1 conduction
13.Prioritization & delegationMedium
An older patient becomes confused over a few hours, with attention that comes and goes. What does this suggest?
ANormal aging that needs no action
BDelirium, which needs the cause found quickly
CA personality change that is permanent and expected
DLong-standing dementia that is expected
14.Prioritization & delegationHard
During START triage, an adult is not breathing. The airway is repositioned and the victim still does not breathe. What is the correct category?
ARed, because no breathing is the most urgent finding
BYellow, and come back later
CRed, and start CPR at once
DBlack (deceased or expectant)
15.Infection control & patient safetyMedium
What should a nurse do after an accidental splash of a patient’s blood into the eyes?
ARub the eyes gently with a clean, dry tissue to remove the blood first
BRinse the eyes at once with plenty of water or saline, then report
CApply antibiotic eye drops and tell no one
DFinish the procedure, then report it the next day
16.Infection control & patient safetyHard
A visitor is receiving an electric shock from a faulty lamp and is still touching it. What should the nurse do first?
AThrow water over the lamp to stop the current
BPull the visitor away from the lamp by the arm as quickly as possible
CStart chest compressions straight away
DSwitch off the power or unplug the lamp without touching the person
17.Lab values & electrolytesMedium
A patient on digoxin has a level of 2.8 ng/mL and a heart rate of 52/min. What is the nurse’s best action?
AGive the dose and recheck the level in a month
BGive a double dose to correct the rhythm
CHold the dose and inform the prescriber
DGive the dose, as the heart rate is above 50/min
18.Lab values & electrolytesHard
A patient has sudden episodes of severe headache, sweating, palpitations and very high blood pressure. Which test is most useful to look for the cause?
APlasma free metanephrines
BSerum calcium only
CFasting lipid profile
DSerum TSH and free T4
3Solutions
1.Nursing fundamentals
Answer: D · From the incision outwards, using a new swab for each stroke
Why this is the answer
The incision is the cleanest area, so cleaning moves from it outwards. Using a fresh swab each time avoids bringing skin bacteria back into the wound.
Answer
D · From the incision outwards, using a new swab for each stroke
2.Nursing fundamentals
Answer: C · Removing the catheter as soon as it is no longer needed
Why this is the answer
The infection risk grows with each day of catheterisation, so the most effective step is avoiding unnecessary catheters and removing them early. Routine bladder washouts and frequent bag changes break the closed system and add risk.
Answer
C · Removing the catheter as soon as it is no longer needed
3.Clinical nursing
Answer: A · Sepsis
Why this is the answer
These three signs form the qSOFA criteria and suggest a high risk of poor outcome from sepsis. Escalate urgently and start the sepsis pathway.
Answer
A · Sepsis
4.Clinical nursing
Answer: D · A patient who has just become breathless after starting an IV antibiotic
Why this is the answer
Breathlessness soon after a new IV antibiotic suggests possible anaphylaxis, an airway and breathing emergency. The infusion should be stopped and the patient assessed immediately.
Answer
D · A patient who has just become breathless after starting an IV antibiotic
5.Arterial blood gas interpretation
Answer: PaCO₂ = 32 mmHg
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.
Winter’s formula
PaCO₂ = 1.5·16 + 8 = 32 mmHg
range: 30–34 mmHg
Answer
PaCO₂ = 32 mmHg
6.Arterial blood gas interpretation
Answer: AGc = 16 mmol/L
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.
Anion gap
AG = 134 − (107 + 15) = 12
Correction for albumin
12 + 0.25·(40 − 24) = 16 mmol/L
Answer
AGc = 16 mmol/L
Above about 12 after correction: a high anion gap.
7.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 22/min → 2
SpO₂ 97% → 0
on air → 0
SBP 110 mmHg → 1
HR 58/min → 0
alert (A) → 0
T 39.6 °C → 2
Add
NEWS2 = 2 + 0 + 0 + 1 + 0 + 0 + 2 = 5
Answer
NEWS2 = 5
8.Clinical assessment scores
Answer: medium
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 12/min → 0
SpO₂ 86% → 3
on air → 0
SBP 222 mmHg → 3
HR 88/min → 0
alert (A) → 0
T 36.9 °C → 0
Total and red scores
NEWS2 = 0 + 3 + 0 + 3 + 0 + 0 + 0 = 6
At least one parameter scores 3.
Risk group
medium
Answer
medium
A total of 5 or more calls for an urgent clinical response.
9.Enteral & parenteral nutrition calculations
Answer: ΔP = 34.6 g/day
Needs and free water: energy needs are often estimated as kcal/kg/day × weight and protein needs as g/kg/day × weight. A formula is only partly water, so its free water = volume × water fraction; water flushes make up the rest of the daily fluid goal. Ideal body weight (Devine): IBW = 50 kg + 2.3 kg for every inch over 5 feet (60 in) for men, and 45.5 kg + 2.3 kg per inch over 60 in for women; 1 in = 2.54 cm. The formula is meant for adults at least 152.4 cm (5 ft) tall. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Protein needed
1.3·51 = 66.3 g/day
Protein from the feed
45·16 = 720 mL = 0.72 L
0.72·44 = 31.68 g/day
Shortfall
ΔP = 66.3 − 31.68 = 34.62 ≈ 34.6 g/day
Answer
ΔP = 34.6 g/day
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 142
Parenteral nutrition: dextrose provides 3.4 kcal/g, amino acids 4 kcal/g and lipid emulsion the kcal/mL stated (2 kcal/mL for 20%, 1.1 kcal/mL for 10%). Grams = % × mL/100. Non-protein kcal (NPC) = dextrose + lipid kcal; nitrogen = protein/6.25. The glucose infusion rate (GIR) in mg/kg/min = dextrose mg/(kg × minutes). The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Grams of dextrose and amino acids
dextrose: 20·1200/100 = 240 g
amino acids: 4·1200/100 = 48 g
Kilocalories per component
dextrose: 240·3.4 = 816 kcal
amino acids: 48·4 = 192 kcal
lipid: 250·1.1 = 275 kcal
Non-protein kcal and nitrogen
NPC = 816 + 275 = 1091 kcal
N = 48/6.25 = 7.68 g
Ratio
NPC : N = 1091/7.68 = 142.1 ≈ 142 : 1
Answer
NPC : N = 142
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: QTc = 0.482 s
QT and QTc: the QT interval runs from the start of the QRS complex to the end of the T wave. It shortens as the heart rate rises, so it is corrected for rate with the R–R interval in seconds: Bazett QTc = QT/√RR and Fridericia QTc = QT/∛RR. Bazett is the formula most textbooks use; it over-corrects at fast rates, where Fridericia is preferred. Limits differ between references: a QTc above about 0.45 s in men or 0.46 s in women is usually called prolonged, and above 0.50 s markedly prolonged.
Measure
QT = 10.5 × 0.04 = 0.42 s
RR = 19 × 0.04 = 0.76 s
Bazett’s formula
QTc = 0.42/√0.76 = 0.42/0.8718 = 0.482 s
Answer
QTc = 0.482 s
Above the usual limits for both men (about 0.45 s) and women (about 0.46 s): prolonged. (482 ms)
12.ECG rhythm strip interpretation
Answer: torsades de pointes
More ventricular rhythms: torsades de pointes is a polymorphic ventricular tachycardia, usually 150–250/min, in which the wide complexes change in height and twist around the baseline, pointing up for a few beats and then down. Textbooks link it to a prolonged QT interval, and magnesium sulfate is the drug resuscitation guidelines name for it. An idioventricular rhythm is a ventricular escape rhythm: regular, wide QRS (0.12 s or more), no P waves, at 20–40/min (an accelerated idioventricular rhythm runs at 40–100/min). Monomorphic VT has identical wide complexes at more than 100/min. VF is chaotic, without any repeating complex.
Five steps
1. Rate: very fast, the complexes are about 6 small boxes apart (about 250 per minute).
2. Rhythm: fast and roughly regular, but the height and direction of the complexes change in a repeating spindle pattern.
3. P waves: none identifiable.
4. PR interval: not measurable.
5. QRS: wide and polymorphic; the complexes twist around the baseline, pointing up for a few beats and then down.
Interpretation
torsades de pointes
Answer
torsades de pointes
Torsades de pointes is a polymorphic VT linked to a prolonged QT interval. This is identification practice only.
13.Prioritization & delegation
Answer: B · Delirium, which needs the cause found quickly
Why this is the answer
Delirium starts suddenly, over hours or days, and attention fluctuates. It often has a treatable cause such as infection, hypoxia or medication, so it is a priority to assess.
Answer
B · Delirium, which needs the cause found quickly
14.Prioritization & delegation
Answer: D · Black (deceased or expectant)
Why this is the answer
In START, a victim who does not breathe after the airway is repositioned is tagged black. CPR for one person would take rescuers away from many others who could survive. If breathing starts after repositioning, the victim is red.
Answer
D · Black (deceased or expectant)
15.Infection control & patient safety
Answer: B · Rinse the eyes at once with plenty of water or saline, then report
Why this is the answer
Mucous membranes are rinsed straight away with plenty of water or saline, for example at an eyewash station. The exposure is reported immediately so the risk can be assessed and post-exposure treatment considered.
Answer
B · Rinse the eyes at once with plenty of water or saline, then report
16.Infection control & patient safety
Answer: D · Switch off the power or unplug the lamp without touching the person
Why this is the answer
The rescuer must not touch someone still in contact with live current. The power is switched off or the plug pulled first, then the person is assessed and resuscitation is started if needed.
Answer
D · Switch off the power or unplug the lamp without touching the person
17.Lab values & electrolytes
Answer: C · Hold the dose and inform the prescriber
Why this is the answer
A level of 2.8 ng/mL is above the usual range, and the slow heart rate fits toxicity. The nurse holds the dose, checks potassium and the ECG and informs the prescriber.
Answer
C · Hold the dose and inform the prescriber
18.Lab values & electrolytes
Answer: A · Plasma free metanephrines
Why this is the answer
These episodes suggest pheochromocytoma, a tumor of the adrenal medulla that releases catecholamines. Plasma free metanephrines (or 24-hour urine metanephrines) are the main screening tests. Hyperthyroidism can cause similar symptoms but usually without these bursts of severe hypertension.Checked against:Pheochromocytoma · MedlinePlus (NIH) (2024)