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.
A nurse realises that a dose of analgesia given two hours ago was not documented. What is correct?
AWrite it in the space for two hours ago as if it was recorded then
BWrite it now as a late entry, stating when it was given
CLeave it out, as it is now too late to record it in the notes
DAsk a colleague to sign that they gave it
3.Clinical nursingMedium
Which is a first-line nursing measure to help prevent constipation in hospital?
AGiving an enema to every patient on admission
BKeeping the patient in bed
CEncouraging fluids, fibre and mobility
DRestricting fluids to reduce urine output
4.Clinical nursingHard
Which ECG change is classically associated with severe hyperkalaemia?
AST depression only
BA shortened PR interval
CProminent U waves
DTall, peaked T waves
5.Arterial blood gas interpretationMedium
Practice values: Na⁺ 151 mmol/L, glucose 9.9 mmol/L and urea 20.3 mmol/L. Calculate the serum osmolality Osm = 2·Na⁺ + glucose + urea to the nearest whole number.
Na⁺ 151 mmol/Lglucose 9.9 mmol/Lurea 20.3 mmol/L
Osm = mOsm/kg
6.Arterial blood gas interpretationHard
A practice gas shows pH 7.29, PaCO₂ 26 mmHg (3.5 kPa) and HCO₃⁻ 12 mmol/L, with Na⁺ 133 and Cl⁻ 93 mmol/L. Use the anion gap and the delta ratio to click the best interpretation.
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: yes; secondary diagnosis: no; ambulatory aid: none, bed rest or nurse assists; IV therapy or saline lock: yes; 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 18/min, SpO₂ 97% on room air, blood pressure 222/134 mmHg, pulse 88/min, alert, temperature 37.1 °C. Which clinical risk group does the patient fall into? Click it.
Practice exercise (made-up values, not clinical guidance). A 68 kg adult (BMI below 30) needs 30 kcal/kg/day. The tube feed provides 1.5 kcal/mL and runs by pump for 24 hours a day. At what rate R do you set the pump, in mL/h? Round to the nearest whole number.
Practice exercise (made-up values, not clinical guidance). Over 24 hours a patient receives 1000 mL of parenteral nutrition with final concentrations of 25% dextrose and 4.25% amino acids, plus 100 mL of 20% lipid emulsion (2 kcal/mL). Find the total energy E the patient receives in kcal per day. Round to the nearest whole number.
1000 mLdextrose 25%amino acids 4.25%lipid 100 mL · 2 kcal/mL
E = kcal/day
11.ECG rhythm strip interpretationMedium
Interpret this lead II rhythm strip. Which rhythm is 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
1ventricular bigeminy
2atrial fibrillation
3sinus rhythm with PVCs
4normal sinus rhythm
12.ECG rhythm strip interpretationHard
This lead II strip shows a conduction problem between the atria and the ventricles. Which rhythm is 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
1third-degree (complete) AV block
2second-degree AV block type I (Wenckebach)
3second-degree AV block type II
4first-degree AV block
13.Prioritization & delegationMedium
A nurse cannot read part of a medication order. What should the nurse do?
AContact the prescriber to clarify the order before giving the drug
BAsk another nurse to guess what the order most likely says, then give it
CSkip the drug and not tell anyone until the next ward round
DGive the usual dose of the drug the nurse thinks was meant
14.Prioritization & delegationHard
A patient at 32 weeks of pregnancy feels dizzy and faint while lying flat on her back. What should the nurse do first?
ASit her upright with her head between her knees
BGive her a sugary drink and keep her flat
CRaise her legs while she stays on her back
DTurn her onto her left side
15.Infection control & patient safetyMedium
Why are some patients screened with a nasal swab for MRSA on admission?
ATo find carriers so precautions or decolonization can be used
BTo diagnose a sinus infection
CTo check whether the patient is allergic to penicillin before surgery
DTo measure the patient’s immunity to MRSA
16.Infection control & patient safetyHard
A chemical cloud has been released near the hospital, and authorities order “shelter in place”. What should staff do?
ASend all visitors home through the main entrance
BKeep everyone inside, close windows and doors and shut off outside air intake
CEvacuate all patients into the car park at once
DOpen the windows to let fresh air into the wards and dilute the chemical
17.Lab values & electrolytesMedium
How does IV calcium gluconate help a patient with severe hyperkalemia?
AIt binds potassium in the gut so that it is passed in the stool
BIt increases potassium excretion by the kidneys
CIt stabilizes heart cell membranes without lowering potassium
DIt moves potassium from the blood into the cells
18.Lab values & electrolytesHard
A patient without diabetes in the ICU with sepsis has a glucose of 260 mg/dL (14.4 mmol/L) and an HbA1c of 5.2%. What is the best interpretation?
AStress hyperglycemia from acute illness
BLong-standing undiagnosed type 2 diabetes
CA meter error, because HbA1c is normal
DType 1 diabetes from autoimmune damage
3Solutions
1.Nursing fundamentals
Answer: C · Airway, Breathing, Circulation, Disability, Exposure
Why this is the answer
ABCDE assesses Airway, Breathing, Circulation, Disability (neurology, glucose) and Exposure, fixing each problem before moving on.
Answer
C · Airway, Breathing, Circulation, Disability, Exposure
2.Nursing fundamentals
Answer: B · Write it now as a late entry, stating when it was given
Why this is the answer
Late entries are clearly marked as such, showing both when care was given and when the note was written. This keeps the record accurate and prevents a second dose being given.
Answer
B · Write it now as a late entry, stating when it was given
3.Clinical nursing
Answer: C · Encouraging fluids, fibre and mobility
Why this is the answer
Adequate fluids, a fibre-rich diet, mobility and privacy for toileting help prevent constipation. Laxatives are added if needed, especially with opioids.
Answer
C · Encouraging fluids, fibre and mobility
4.Clinical nursing
Answer: D · Tall, peaked T waves
Why this is the answer
Hyperkalaemia causes peaked T waves, then a widened QRS and possibly a sine-wave pattern and arrest. Hypokalaemia causes flat T waves and U waves.
Answer
D · Tall, peaked T waves
5.Arterial blood gas interpretation
Answer: Osm = 332 mOsm/kg
Derived values: calculated serum osmolality is 2·Na⁺ + glucose + urea with all values in mmol/L (2·Na⁺ + glucose/18 + BUN/2.8 with glucose and BUN in mg/dL); normal is about 275–295 mOsm/kg. The P/F ratio is PaO₂ divided by FiO₂ as a fraction. The alveolar oxygen pressure is PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 mmHg at sea level, and the A–a gradient is PAO₂ − PaO₂.
Calculated osmolality
Osm = 2·151 + 9.9 + 20.3 = 332.2 ≈ 332 mOsm/kg
Answer
Osm = 332 mOsm/kg
6.Arterial blood gas interpretation
Answer: pure high-gap acidosis
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 = 133 − (93 + 12) = 28
Delta ratio
(28 − 12)/(24 − 12) = 1.333
pure high-gap acidosis
Answer
pure high-gap acidosis
7.Clinical assessment scores
Answer: MFS = 45
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: yes → 25
secondary diagnosis: no → 0
ambulatory aid: none, bed rest or nurse assists → 0
IV therapy or saline lock: yes → 20
gait: normal, bed rest or wheelchair → 0
mental status: knows own limits → 0
Add
Morse total = 25 + 0 + 0 + 20 + 0 + 0 = 45
Answer
MFS = 45
8.Clinical assessment scores
Answer: low–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 18/min → 0
SpO₂ 97% → 0
on air → 0
SBP 222 mmHg → 3
HR 88/min → 0
alert (A) → 0
T 37.1 °C → 0
Total and red scores
NEWS2 = 0 + 0 + 0 + 3 + 0 + 0 + 0 = 3
At least one parameter scores 3.
Risk group
low–medium
Answer
low–medium
A single score of 3 needs an urgent review even when the total is low.
9.Enteral & parenteral nutrition calculations
Answer: R = 57 mL/h
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.
Energy needed
E = 30·68 = 2040 kcal/day
Daily volume
V = 2040/1.5 = 1360 mL/day
Pump rate
R = 1360/24 = 56.67 ≈ 57 mL/h
Answer
R = 57 mL/h
10.Enteral & parenteral nutrition calculations
Answer: E = 1220 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: 25·1000/100 = 250 g
amino acids: 4.25·1000/100 = 42.5 g
Kilocalories per component
dextrose: 250·3.4 = 850 kcal
amino acids: 42.5·4 = 170 kcal
lipid: 100·2 = 200 kcal
Total energy
E = 850 + 170 + 200 = 1220 kcal/day
Answer
E = 1220 kcal/day
11.ECG rhythm strip interpretation
Answer: ventricular bigeminy
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.
Five steps
1. Rate: 8 QRS complexes in 6 s, × 10 = 80 per minute.
2. Rhythm: regularly irregular, a short and a long R–R alternate (0.44 s and 1.16 s).
3. P waves: upright before every narrow QRS; none before the early wide beats.
4. PR interval: 0.14 s, constant, within 0.12–0.20 s.
5. QRS: 0.06 s in the sinus beats; the early beats are wide (0.14 s) and bizarre, with the T wave pointing the other way.
Interpretation
ventricular bigeminy
Answer
ventricular bigeminy
12.ECG rhythm strip interpretation
Answer: third-degree (complete) AV block
AV blocks: march out the P waves and check which ones are followed by a QRS. First-degree: every P conducted, PR constant and above 0.20 s. Second-degree type I (Mobitz I, Wenckebach): the PR lengthens from beat to beat until one P wave is not conducted, then the cycle starts again (group beating). Second-degree type II (Mobitz II): the PR of the conducted beats stays constant, and P waves are suddenly not conducted; the QRS is often wide. Third-degree (complete) block: P waves and QRS complexes are each regular but independent, the PR varies at random and the atrial rate is faster than the escape rate (junctional 40–60/min with a narrow QRS, ventricular 20–40/min with a wide QRS). A 2:1 block cannot be called type I or type II from one strip.
Five steps
1. Rate: R–R = 30 small boxes, 1500 ÷ 30 ≈ 50 per minute.
2. Rhythm: R–R regular (1.20 s) and P–P regular (0.84 s), but the two are independent.
3. P waves: upright and regular at 71 per minute, but not linked to the QRS complexes; some hide in a QRS or a T wave.
4. PR interval: varies from beat to beat; there is no fixed relation.
5. QRS: 0.08 s, narrow (below 0.12 s).
Interpretation
third-degree (complete) AV block
Answer
third-degree (complete) AV block
Type II and third-degree blocks are the ones that can suddenly progress, so textbooks rank them as more serious than type I.
13.Prioritization & delegation
Answer: A · Contact the prescriber to clarify the order before giving the drug
Why this is the answer
An unclear order must be clarified with the prescriber before the medication is given. Guessing or ignoring the order can harm the patient.
Answer
A · Contact the prescriber to clarify the order before giving the drug
14.Prioritization & delegation
Answer: D · Turn her onto her left side
Why this is the answer
Lying on the back lets the uterus compress the inferior vena cava, reducing blood return to the heart. Turning to the left side relieves the pressure and restores the blood pressure.
Answer
D · Turn her onto her left side
15.Infection control & patient safety
Answer: A · To find carriers so precautions or decolonization can be used
Why this is the answer
Screening identifies people who are colonized with MRSA, often in the nose. Precautions and, in some cases, decolonization reduce spread and the risk of the patient’s own infection after surgery.
Answer
A · To find carriers so precautions or decolonization can be used
16.Infection control & patient safety
Answer: B · Keep everyone inside, close windows and doors and shut off outside air intake
Why this is the answer
Sheltering in place keeps people inside, away from the hazard. Windows and doors are closed and ventilation systems that bring in outside air are shut off until the all-clear.
Answer
B · Keep everyone inside, close windows and doors and shut off outside air intake
17.Lab values & electrolytes
Answer: C · It stabilizes heart cell membranes without lowering potassium
Why this is the answer
Calcium counteracts the effect of high potassium on the heart’s electrical activity within minutes. The potassium must still be lowered by shifting it into cells (insulin with glucose) and removing it (binders, diuretics or dialysis).Checked against:High potassium level · MedlinePlus (NIH) (2025)
Answer
C · It stabilizes heart cell membranes without lowering potassium
18.Lab values & electrolytes
Answer: A · Stress hyperglycemia from acute illness
Why this is the answer
Stress hormones and inflammation raise glucose in acute illness, even without diabetes. A normal HbA1c shows that glucose was normal over the previous months. Stress hyperglycemia is still treated, usually with insulin, because it worsens outcomes.Checked against:Hemoglobin A1C (HbA1c) Test · MedlinePlus (NIH) (2025)