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 should a patient collect a midstream urine sample?
APass the first part into the toilet, then catch the middle part in the pot
BCollect urine from the toilet bowl after passing it
CCollect the very first part of the stream in the pot, then pass the rest into the toilet
DCollect the last few drops after the bladder is empty
2.Nursing fundamentalsHard
When is a "clean" (non-sterile) technique acceptable instead of an aseptic technique?
AFor dressing a fresh surgical wound in theatre, provided that non-sterile gloves are worn throughout
BFor inserting a urinary catheter
CFor procedures that do not enter sterile body areas, such as giving an oral medicine
DFor inserting a central venous catheter
3.Clinical nursingMedium
What is one advantage of a direct oral anticoagulant (DOAC) such as apixaban compared with warfarin?
AIt does not need routine INR monitoring
BIt has no risk of bleeding
CIt is safe in all patients with severe kidney failure
DIt never interacts with other drugs
4.Clinical nursingHard
An older patient with delirium is trying to leave the ward at night, saying he must go home. What is the best initial approach?
AGive a sedative straight away without a prescription
BPhysically restrain him in bed until the morning so that he cannot fall
CLet him leave, because adults can always do as they wish whatever their state
DCalmly reassure and redirect him while the team assesses his capacity and safety
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.24, PaCO₂ 43 mmHg (5.7 kPa) and HCO₃⁻ 18 mmol/L. The primary disorder is metabolic acidosis. How far is it compensated? Click your answer.
pH 7.24PaCO₂ 43 mmHg (5.7 kPa)HCO₃⁻ 18 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
A practice gas shows a metabolic acidosis: pH 7.22, PaCO₂ 35 mmHg (4.7 kPa), HCO₃⁻ 14 mmol/L. Compare the measured PaCO₂ with Winter’s formula. Click your interpretation.
pH 7.22PaCO₂ 35 mmHg (4.7 kPa)HCO₃⁻ 14 mmol/L
1appropriate compensation
2added respiratory acidosis
3added respiratory alkalosis
7.Clinical assessment scoresMedium
Practice exercise (made-up values, not clinical guidance). A practice patient after a head injury does not open the eyes at all, makes no sounds and shows as the best motor response: no movement at all. Work out the GCS and classify the head injury by it. Click your answer.
1mild
2moderate
3severe
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 32/min, SpO₂ 96% on room air, blood pressure 112/68 mmHg, pulse 70/min, alert, temperature 37.9 °C. Which clinical risk group does the patient fall into? Click it.
Practice exercise (made-up values, not clinical guidance). A 90 kg patient needs 1.8 g of protein per kg a day. The tube feed contains 68 g of protein per litre and runs at 85 mL/h for 20 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 17.5% dextrose and 6% 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.
1200 mLdextrose 17.5%amino acids 6%lipid 500 mL · 1.1 kcal/mL
E = kcal/day
11.ECG rhythm strip interpretationMedium
Measure the QT interval on this lead II strip, in seconds.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
QT = s
12.ECG rhythm strip interpretationHard
This lead II strip shows an AV block, so the atria and the ventricles beat at different rates. The QRS complexes are regular: find the ventricular rate in beats per minute (1500 method, whole number).
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
13.Prioritization & delegationMedium
A nurse teaches a patient who uses home oxygen. Which statement shows a need for further teaching?
A“I will not use oil-based creams on my face.”
B“My husband can smoke in my room if the window is open.”
C“I will keep the oxygen away from the gas stove.”
D“I will put up no-smoking signs at the front door and in my room.”
14.Prioritization & delegationHard
In an emergency department, which patient should go straight to a treatment room?
AA 30-year-old with a sore throat for two days and a temperature of 38.0 °C
BA 60-year-old with chest pressure, sweating and nausea for 20 minutes
CA 45-year-old asking for a repeat prescription
DA 25-year-old with a sprained wrist and normal vital signs
15.Infection control & patient safetyMedium
Before a blood transfusion is started, which check is required?
AOne nurse checks the blood product against the order at the nurses’ station
BThe patient signs the blood bag label to confirm their name before it is hung
CThe patient’s identity is checked against the blood product and its paperwork at the bedside
DThe nurse checks only that the bag number matches the order
16.Infection control & patient safetyHard
A nurse often skips barcode scanning to save time, as many colleagues do. In a just culture, how is this behavior classed?
AReckless behavior, managed by immediate dismissal and reporting to the licensing board
BSimple human error, managed only by consoling the nurse and moving on
CAcceptable behavior, because it is common on the unit
DAt-risk behavior, managed by coaching and fixing the system pressures behind it
17.Lab values & electrolytesMedium
A patient with suspected pulmonary TB needs sputum samples for acid-fast bacilli. Which instruction is correct?
AGive one sample after brushing with mouthwash so it is clean
BGive several deep-cough samples, often first thing in the morning
CGive one sample of saliva collected from the mouth at any time of day
DGive several samples of nasal mucus blown into a tissue
18.Lab values & electrolytesHard
On the evening after surgery, a patient’s hemoglobin has fallen from 12.5 g/dL to 8.1 g/dL (125 to 81 g/L), and the heart rate is 118/min. What is the most likely problem?
ADehydration
BBleeding
CAn improving condition
DNormal dilution after surgery that needs no action
3Solutions
1.Nursing fundamentals
Answer: A · Pass the first part into the toilet, then catch the middle part in the pot
Why this is the answer
After cleaning, the first stream flushes bacteria from the urethra, so the midstream part is collected in a sterile container. This reduces contamination.
Answer
A · Pass the first part into the toilet, then catch the middle part in the pot
2.Nursing fundamentals
Answer: C · For procedures that do not enter sterile body areas, such as giving an oral medicine
Why this is the answer
Aseptic technique is required when entering normally sterile sites or handling key parts of invasive devices. Routine non-invasive tasks only need standard precautions.
Answer
C · For procedures that do not enter sterile body areas, such as giving an oral medicine
3.Clinical nursing
Answer: A · It does not need routine INR monitoring
Why this is the answer
DOACs have predictable effects so INR monitoring is not needed. They still cause bleeding, have some interactions and need kidney function checked.
Answer
A · It does not need routine INR monitoring
4.Clinical nursing
Answer: D · Calmly reassure and redirect him while the team assesses his capacity and safety
Why this is the answer
De-escalation, reorientation and supervision come first. If he lacks capacity, the team must act in his best interests using the least restrictive measures, following local law and policy.
Answer
D · Calmly reassure and redirect him while the team assesses his capacity and safety
5.Arterial blood gas interpretation
Answer: uncompensated
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 7.24: acidaemia (below 7.35)
PaCO₂ 43 mmHg: normal (35–45)
HCO₃⁻ 18 mmol/L: low (22–26)
Compensation
Clinically, also check the expected compensation: Winter’s formula expects PaCO₂ 33–37 mmHg, so the measured 43 mmHg points to an additional respiratory acidosis (a mixed disorder). The answer above is the ROME exam classification.
uncompensated
Answer
uncompensated
6.Arterial blood gas interpretation
Answer: added respiratory 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.
Expected PaCO₂
1.5·14 + 8 = 29 → 27–31 mmHg
Compare
measured: 35 mmHg → added respiratory acidosis
Answer
added respiratory acidosis
7.Clinical assessment scores
Answer: severe
Glasgow Coma Scale: add the best response in three areas. Eye opening E: 4 spontaneous, 3 to sound or speech, 2 to pressure, 1 none. Verbal V: 5 oriented, 4 confused, 3 inappropriate words, 2 incomprehensible sounds, 1 none. Motor M: 6 obeys commands, 5 localises, 4 normal flexion (withdraws), 3 abnormal flexion, 2 extension, 1 none. The total runs from 3 to 15. After a head injury, 13–15 is usually called mild, 9–12 moderate and 3–8 severe.
Score each area
E: does not open the eyes at all → 1
V: makes no sounds → 1
M: no movement at all → 1
Add
GCS = 1 + 1 + 1 = 3
Severity
GCS 3 → severe
Answer
severe
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 32/min → 3
SpO₂ 96% → 0
on air → 0
SBP 112 mmHg → 0
HR 70/min → 0
alert (A) → 0
T 37.9 °C → 0
Total and red scores
NEWS2 = 3 + 0 + 0 + 0 + 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: ΔP = 46.4 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
1.8·90 = 162 g/day
Protein from the feed
85·20 = 1700 mL = 1.7 L
1.7·68 = 115.6 g/day
Shortfall
ΔP = 162 − 115.6 = 46.4 g/day
Answer
ΔP = 46.4 g/day
10.Enteral & parenteral nutrition calculations
Answer: E = 1552 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: 17.5·1200/100 = 210 g
amino acids: 6·1200/100 = 72 g
Kilocalories per component
dextrose: 210·3.4 = 714 kcal
amino acids: 72·4 = 288 kcal
lipid: 500·1.1 = 550 kcal
Total energy
E = 714 + 288 + 550 = 1552 kcal/day
Answer
E = 1552 kcal/day
11.ECG rhythm strip interpretation
Answer: QT = 0.5 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
12.5 small boxes from the start of the QRS to the end of the T wave
Convert
QT = 12.5 × 0.04 s = 0.5 s
Answer
QT = 0.5 s
A rough rule: at normal rates the QT should be less than half the R–R interval (here R–R = 0.96 s).
12.ECG rhythm strip interpretation
Answer: ventricular rate = 42 bpm
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.
Atrial rate
P–P = 21 small boxes = 0.84 s → 1500 ÷ 21 = 71.43 ≈ 71 per minute
Ventricular rate
R–R = 36 small boxes = 1.44 s → 1500 ÷ 36 = 41.67 ≈ 42 per minute
Answer
ventricular rate = 42 bpm
Answer
ventricular rate = 42 bpm
Third-degree block with a narrow-complex junctional escape (usually 40–60 per minute).
13.Prioritization & delegation
Answer: B · “My husband can smoke in my room if the window is open.”
Why this is the answer
Oxygen supports combustion, so no one may smoke near it, even with a window open. Keeping it away from flames and avoiding oil-based products are correct.
Answer
B · “My husband can smoke in my room if the window is open.”
14.Prioritization & delegation
Answer: B · A 60-year-old with chest pressure, sweating and nausea for 20 minutes
Why this is the answer
Chest pressure with sweating and nausea may be a heart attack, so the patient needs an ECG within minutes. The other patients are stable and can safely wait.
Answer
B · A 60-year-old with chest pressure, sweating and nausea for 20 minutes
15.Infection control & patient safety
Answer: C · The patient’s identity is checked against the blood product and its paperwork at the bedside
Why this is the answer
Wrong-patient transfusion can cause a fatal ABO reaction, so the final check is always done at the bedside, with positive patient identification against the product label, compatibility tag and order. Many US hospitals require two qualified people for this check, while UK guidance allows one trained person if positive identification is used. Local policy decides who checks.
Answer
C · The patient’s identity is checked against the blood product and its paperwork at the bedside
16.Infection control & patient safety
Answer: D · At-risk behavior, managed by coaching and fixing the system pressures behind it
Why this is the answer
At-risk behavior is a choice whose risk is not recognized or is believed to be justified, often because shortcuts have become normal. It is managed by coaching and removing the pressures behind it, while reckless behavior may need disciplinary action.
Answer
D · At-risk behavior, managed by coaching and fixing the system pressures behind it
17.Lab values & electrolytes
Answer: B · Give several deep-cough samples, often first thing in the morning
Why this is the answer
Usually a series of three sputum samples is collected, at least one in the early morning, when secretions have pooled overnight. The patient rinses with water (not mouthwash), takes deep breaths and coughs deeply to bring up sputum, not saliva. Airborne precautions are used.Checked against:Sputum Culture · MedlinePlus (NIH) (2024); Acid-Fast Bacillus (AFB) Tests · MedlinePlus (NIH) (2025)
Answer
B · Give several deep-cough samples, often first thing in the morning
18.Lab values & electrolytes
Answer: B · Bleeding
Why this is the answer
A fall of more than 4 g/dL with a fast heart rate suggests ongoing blood loss. The nurse assesses the wound and drains, monitors the vital signs and escalates urgently. Some dilution from IV fluids is common, but not this much, and not with tachycardia.Checked against:Hemoglobin Test · MedlinePlus (NIH) (2024)