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.
Keep sterile items sterile: if in doubt, it is not sterile; replace, never wipe.
Prevent harm in the environment: fall measures, restraints only as a last resort, RACE and PASS for fire.
Check the rights of medication administration, two identifiers and extra safeguards for high-alert drugs; report errors and near misses.
Lab values & electrolytes
Method
Compare the value with the laboratory’s own reference range, then with the patient’s baseline and trend.
Check the sample: hemolysis, a delay, or blood drawn near an IV can give false results.
Link the value to its typical signs and to the drugs and conditions that cause it.
Look for interactions: low potassium or magnesium increases digoxin toxicity; dehydration raises lithium.
Act on the patient: assess, hold a drug if the level is unsafe, read back critical values and inform the prescriber.
2Practice problems
1.Nursing fundamentalsMedium
How can nurses help patients sleep better on a hospital ward at night?
AGroup care and observations so patients are disturbed less often
BDo routine tasks such as bed changes at midnight while it is quiet
CKeep the main lights on so staff can see clearly
DGive every patient a sleeping tablet
2.Nursing fundamentalsHard
A patient on regular paracetamol (acetaminophen) also takes an over-the-counter cold and flu remedy. Why is this a concern?
AThere is no concern, as cold remedies contain no drugs
BCold remedies stop paracetamol from working, so the pain will not be controlled
CMany cold remedies also contain paracetamol, risking liver damage
DParacetamol makes cold remedies cause drowsiness
3.Clinical nursingMedium
Which technique is correct when suctioning through a tracheostomy?
ASuction every 15 minutes whether or not secretions are present
BKeep suctioning for at least a minute each time to clear all the secretions
CApply suction continuously while inserting the catheter as far as it will go
DApply suction only while withdrawing the catheter, for no more than about 10–15 seconds
4.Clinical nursingHard
A nurse notices that a wrong dose of a drug was prepared but was caught before it was given. What should be done?
ATell only the patient's family
BReport it as a near miss through the incident reporting system
CSay nothing, because no harm reached the patient
DDiscipline the nurse who prepared it on the spot in front of colleagues
5.Arterial blood gas interpretationMedium
A practice gas shows PaCO₂ 55 mmHg (7.3 kPa). Use the rule that in acute respiratory acidosis HCO₃⁻ rises by 1 mmol/L for every 10 mmHg that PaCO₂ is above 40, starting from HCO₃⁻ 24 mmol/L, to find the expected HCO₃⁻.
Practice exercise (made-up values, not clinical guidance). A practice patient is assessed with the Morse fall scale: history of falling in the last 3 months: no; secondary diagnosis: yes; ambulatory aid: crutches, cane or walker; IV therapy or saline lock: no; gait: normal, bed rest or wheelchair; mental status: knows own limits. Find the Morse total MFS.
0–125
MFS =
8.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 96% on room air, blood pressure 124/74 mmHg, pulse 82/min, alert, temperature 37.2 °C. Which clinical risk group does the patient fall into? Click it.
Practice exercise (made-up values, not clinical guidance). A 75 kg patient needs 1.2 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 1500 mL of parenteral nutrition with final concentrations of 25% dextrose and 4% amino acids, plus 500 mL of 10% lipid emulsion (1.1 kcal/mL). Find the total energy E the patient receives in kcal per day. Round to the nearest whole number.
1500 mLdextrose 25%amino acids 4%lipid 500 mL · 1.1 kcal/mL
E = kcal/day
11.ECG rhythm strip interpretationMedium
This lead II strip shows atrial flutter with a fixed conduction ratio. Find the ventricular rate in beats per minute.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
ventricular rate = bpm
12.ECG rhythm strip interpretationHard
A patient without a palpable pulse has this organised rhythm on the monitor (pulseless electrical activity). Which treatment do adult resuscitation guidelines name for it? 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
1immediate defibrillation
2synchronised cardioversion
3transcutaneous pacing
4CPR (non-shockable rhythm)
13.Prioritization & delegationMedium
A nurse needs to give report on a patient to a colleague. Which information is the most important to include?
APersonal opinions about the patient’s family members and their visiting habits
BDetails of the nurse’s own break times that shift
CThe patient’s current condition, recent changes and pending tasks
DThe patient’s favorite television programs and hobbies
14.Prioritization & delegationHard
A patient suddenly has severe pain in one leg. The leg is pale and cold with no pedal pulse. What does this suggest?
AA muscle cramp that will pass with stretching
BAcute arterial occlusion, which is an emergency
CChronic venous insufficiency that needs elevation
DA deep vein thrombosis that can be treated next week
15.Infection control & patient safetyMedium
The barcode scanner warns that the medication does not match the patient’s record. What should the nurse do?
AOverride the warning and give the medication
BGive the medication and report the warning later in the shift
CStop and find out why before giving the medication
DScan a different patient’s wristband
16.Infection control & patient safetyHard
On the morning of surgery, a patient says the operation is on the left knee, but the consent form says right knee. What should the nurse do?
AFollow the consent form, because it has been signed
BStop and tell the surgeon, so the site is confirmed first
CMark both knees so either can be operated on
DFollow the patient, because they know their own body best
17.Lab values & electrolytesMedium
Apart from the lithium level, which tests are monitored regularly in long-term lithium therapy?
AINR and the platelet count
BKidney function and thyroid function
CLiver enzymes and serum amylase
DTroponin and creatine kinase (CK)
18.Lab values & electrolytesHard
A patient receiving IV magnesium sulfate has a respiratory rate of 9/min and absent patellar reflexes. After stopping the infusion, which medication should the nurse expect to give?
ASodium bicarbonate
BPotassium chloride
CCalcium gluconate
DProtamine sulfate
3Solutions
1.Nursing fundamentals
Answer: A · Group care and observations so patients are disturbed less often
Why this is the answer
Clustering care, dimming lights, reducing noise and offering eye masks or earplugs improve sleep. Sedatives carry risks and are not routine.
Answer
A · Group care and observations so patients are disturbed less often
2.Nursing fundamentals
Answer: C · Many cold remedies also contain paracetamol, risking liver damage
Why this is the answer
Paracetamol is in many combination products. Taking several at once can push the total over the safe daily maximum and cause liver damage, so patients are taught to check labels.
Answer
C · Many cold remedies also contain paracetamol, risking liver damage
3.Clinical nursing
Answer: D · Apply suction only while withdrawing the catheter, for no more than about 10–15 seconds
Why this is the answer
Suctioning only on withdrawal and keeping it brief reduces hypoxia and mucosal damage. Suction is performed when needed, not routinely, and the patient is pre-oxygenated if required.
Answer
D · Apply suction only while withdrawing the catheter, for no more than about 10–15 seconds
4.Clinical nursing
Answer: B · Report it as a near miss through the incident reporting system
Why this is the answer
Near misses are reported so that causes can be studied and systems improved. A just, open culture encourages reporting without blame.
Answer
B · Report it as a near miss through the incident reporting system
5.Arterial blood gas interpretation
Answer: HCO₃⁻ = 25.5 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.
Change in PaCO₂
|55 − 40| = 15 mmHg → 1.5 × 10 mmHg
Expected HCO₃⁻
HCO₃⁻ = 24 + 1·1.5 = 25.5 mmol/L
Answer
HCO₃⁻ = 25.5 mmol/L
6.Arterial blood gas interpretation
Answer: AGc = 24.25 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 = 138 − (109 + 10) = 19
Correction for albumin
19 + 0.25·(40 − 19) = 24.25 mmol/L
Answer
AGc = 24.25 mmol/L
Above about 12 after correction: a high anion gap.
7.Clinical assessment scores
Answer: MFS = 30
Morse fall scale: six items. History of falling: no 0, yes 25. Secondary diagnosis: no 0, yes 15. Ambulatory aid: none, bed rest or nurse assistance 0; crutches, cane or walker 15; holding on to furniture 30. IV therapy or saline lock: no 0, yes 20. Gait: normal, bed rest or wheelchair 0; weak 10; impaired 20. Mental status: knows own limits 0; overestimates or forgets limits 15. The total runs from 0 to 125. Risk cut-offs differ between hospitals; a common set is 0–24 low, 25–44 moderate and 45 or more high.
Score each item
history of falling in the last 3 months: no → 0
secondary diagnosis: yes → 15
ambulatory aid: crutches, cane or walker → 15
IV therapy or saline lock: no → 0
gait: normal, bed rest or wheelchair → 0
mental status: knows own limits → 0
Add
Morse total = 0 + 15 + 15 + 0 + 0 + 0 = 30
Answer
MFS = 30
8.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 96% → 0
on air → 0
SBP 124 mmHg → 0
HR 82/min → 0
alert (A) → 0
T 37.2 °C → 0
Total and red scores
NEWS2 = 2 + 0 + 0 + 0 + 0 + 0 + 0 = 2
No parameter scores 3.
Risk group
low
Answer
low
9.Enteral & parenteral nutrition calculations
Answer: ΔP = 58.3 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
1.2·75 = 90 g/day
Protein from the feed
45·16 = 720 mL = 0.72 L
0.72·44 = 31.68 g/day
Shortfall
ΔP = 90 − 31.68 = 58.32 ≈ 58.3 g/day
Answer
ΔP = 58.3 g/day
10.Enteral & parenteral nutrition calculations
Answer: E = 2065 kcal/day
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: 25·1500/100 = 375 g
amino acids: 4·1500/100 = 60 g
Kilocalories per component
dextrose: 375·3.4 = 1275 kcal
amino acids: 60·4 = 240 kcal
lipid: 500·1.1 = 550 kcal
Total energy
E = 1275 + 240 + 550 = 2065 kcal/day
Answer
E = 2065 kcal/day
11.ECG rhythm strip interpretation
Answer: ventricular rate = 75 bpm
Rhythm criteria (lead II): sinus rhythm has an upright P wave before every QRS, a constant PR of 0.12–0.20 s and a narrow QRS: normal sinus rhythm at 60–100/min, sinus bradycardia below 60, sinus tachycardia above 100. Atrial fibrillation: no P waves, a fibrillatory baseline and an irregularly irregular R–R. Atrial flutter: sawtooth flutter waves at about 250–350/min with a fixed conduction ratio such as 2:1 or 4:1. First-degree AV block: sinus rhythm with a constant PR above 0.20 s. Junctional rhythm: narrow QRS at 40–60/min with absent or inverted P waves (PR below 0.12 s, or P after the QRS). A PVC is an early, wide (0.12 s or more), bizarre QRS without a P wave, with the T wave in the opposite direction and usually a full compensatory pause; in bigeminy every second beat is a PVC.
Flutter waves
F–F = 5 small boxes = 0.20 s → 1500 ÷ 5 = 300 per minute
QRS complexes
R–R = 20 small boxes = 0.80 s → 1500 ÷ 20 = 75 per minute
conduction ratio = 300 ÷ 75 = 4:1
Answer
ventricular rate = 75 bpm
12.ECG rhythm strip interpretation
Answer: CPR (non-shockable rhythm)
Pulseless electrical activity (PEA): PEA cannot be seen on a strip. The monitor shows organised electrical activity (a rhythm other than VF, VT or asystole) but the patient has no palpable pulse, so it is recognised by checking the patient. In adult resuscitation guidelines PEA and asystole are the non-shockable cardiac arrest rhythms: high-quality CPR, epinephrine as soon as possible and a search for reversible causes (the Hs and Ts, such as hypovolaemia, hypoxia, tension pneumothorax and cardiac tamponade). VF and pulseless VT are the shockable rhythms.
What the strip shows
1. Rate: R–R = 34 small boxes, 1500 ÷ 34 ≈ 44 per minute.
2. Rhythm: regular, every R–R is 1.36 s.
3. P waves: upright, one before every QRS, all alike.
4. PR interval: 0.20 s, constant, within 0.12–0.20 s.
5. QRS: 0.10 s, narrow (below 0.12 s).
sinus bradycardia
What the patient shows
no pulse despite organised electrical activity: pulseless electrical activity (PEA), a non-shockable cardiac arrest rhythm
Answer
CPR (non-shockable rhythm)
Answer
CPR (non-shockable rhythm)
PEA is recognised at the bedside, never from the strip alone. This is exam practice, not clinical guidance.
13.Prioritization & delegation
Answer: C · The patient’s current condition, recent changes and pending tasks
Why this is the answer
Effective handover covers the current status, changes, risks and outstanding tasks, often using a structure such as SBAR. Opinions and unrelated details distract from what matters.
Answer
C · The patient’s current condition, recent changes and pending tasks
14.Prioritization & delegation
Answer: B · Acute arterial occlusion, which is an emergency
Why this is the answer
Sudden pain, pallor, coldness and loss of pulse suggest an embolus blocking an artery. The limb can be lost within hours, so the nurse escalates immediately.
Answer
B · Acute arterial occlusion, which is an emergency
15.Infection control & patient safety
Answer: C · Stop and find out why before giving the medication
Why this is the answer
Barcode warnings exist to catch wrong-patient, wrong-drug and wrong-dose errors. The nurse stops and checks the order and the product, and contacts the pharmacy or prescriber. Overriding warnings out of habit causes errors.
Answer
C · Stop and find out why before giving the medication
16.Infection control & patient safety
Answer: B · Stop and tell the surgeon, so the site is confirmed first
Why this is the answer
Wrong-site surgery prevention depends on confirming the correct site from several sources. A discrepancy stops the process until the surgeon has verified the correct site with the patient and records, and the consent is corrected if needed.
Answer
B · Stop and tell the surgeon, so the site is confirmed first
17.Lab values & electrolytes
Answer: B · Kidney function and thyroid function
Why this is the answer
Long-term lithium can cause hypothyroidism and impair kidney function, including nephrogenic diabetes insipidus. Creatinine/eGFR and TSH are therefore checked regularly, together with sodium and the lithium level.Checked against:Hypothyroidism · MedlinePlus (NIH) (2024)
Answer
B · Kidney function and thyroid function
18.Lab values & electrolytes
Answer: C · Calcium gluconate
Why this is the answer
Absent reflexes and slow breathing indicate magnesium toxicity. The infusion is stopped, the provider is called, the airway and breathing are supported, and IV calcium gluconate is given as prescribed to counteract magnesium.