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
What is informed consent?
AA signed form that removes all liability from staff for any harm caused by the procedure
BA signature from any family member
CAgreement obtained after the procedure
DVoluntary agreement by a patient with capacity, after receiving adequate information
2.Nursing fundamentalsHard
A stable patient is woken every hour for observations and is becoming tired and confused. What is the best nursing action?
AStop all observations so the patient can sleep
BAsk the team whether the observations can safely be done less often
CKeep the same plan, as observations matter more than sleep for patients
DAsk the doctor for a sedative to help the patient sleep
3.Clinical nursingMedium
Why is oxygen often humidified for a patient with a tracheostomy?
AHumidification lowers the oxygen concentration to a safer level
BHumidity is needed for the oxygen to work as a drug
CThe tube bypasses the nose, which normally warms and moistens air
DDry oxygen causes high blood glucose
4.Clinical nursingHard
Which finding most strongly suggests a pulmonary embolism in a postoperative patient?
ASlow heart rate with high blood pressure
BSudden breathlessness and pleuritic chest pain with tachycardia
CGradual onset of cough with yellow sputum and mild fever over a week
DWheeze that improves with salbutamol
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.43, PaCO₂ 31 mmHg (4.1 kPa) and HCO₃⁻ 20 mmol/L. The primary disorder is respiratory alkalosis. How far is it compensated? Click your answer.
pH 7.43PaCO₂ 31 mmHg (4.1 kPa)HCO₃⁻ 20 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
A practice gas shows pH 7.30, PaCO₂ 25 mmHg (3.3 kPa) and HCO₃⁻ 12 mmol/L, with Na⁺ 138 and Cl⁻ 110 mmol/L. Use the anion gap and the delta ratio to click the best interpretation.
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 16/min, SpO₂ 95% on room air, blood pressure 118/70 mmHg, pulse 64/min, alert, temperature 36.0 °C. What is the NEWS2 total score?
RR 16SpO₂ 95%airSBP 118HR 64AT 36.0 °C
NEWS2 =
8.Clinical assessment scoresHard
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: holds on to furniture; IV therapy or saline lock: yes; gait: normal, bed rest or wheelchair; mental status: overestimates or forgets limits. Using the cut-offs 0–24 low, 25–44 moderate and 45 or more high, click the fall-risk level.
Practice exercise (made-up values, not clinical guidance). A 50 kg patient needs 1.3 g of protein per kg a day. The tube feed contains 40 g of protein per litre and runs at 60 mL/h for 18 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 2000 mL of parenteral nutrition with final concentrations of 25% dextrose and 4.25% amino acids, plus 250 mL of 20% lipid emulsion (2 kcal/mL). Find the non-protein kilocalorie to nitrogen ratio NPC : N (the number x in x : 1). Round to the nearest whole number.
2000 mLdextrose 25%amino acids 4.25%lipid 250 mL · 2 kcal/mL
NPC : N =
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
1junctional rhythm
2sinus bradycardia
3first-degree AV block
4sinus tachycardia
12.ECG rhythm strip interpretationHard
Interpret this lead II strip with the five steps in order: rate, rhythm, P waves, PR interval, QRS duration. At which step do you find the first abnormal finding? Click it.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
1rate
2rhythm
3P waves
4PR interval
5QRS duration
13.Prioritization & delegationMedium
Which task should the nurse delegate to a nursing assistant for a patient on fall precautions?
AAssessing and recording the patient’s fall risk score each morning
BDeciding whether the bed alarm is still needed
CTeaching the family how to prevent falls at home
DHelping the patient to the toilet every 2 hours as planned
14.Prioritization & delegationHard
Which task is most appropriate for the RN to do personally rather than delegate to a nursing assistant?
ATaking a stable patient for a walk in the corridor on the third day after surgery
BGetting a patient out of bed for the first time after surgery
CWeighing a patient with heart failure each morning
DHelping a patient with oral care
15.Infection control & patient safetyMedium
Before helping a patient from bed into a wheelchair, what should the nurse do with the wheelchair?
APlace it on the patient’s weaker side so that side is supported
BPlace it at the foot of the bed, facing away
CLeave the brakes off so the chair can move along with the patient during the pivot
DLock the brakes and place it close to the bed on the patient’s stronger side
16.Infection control & patient safetyHard
A patient dies after a wrong-drug error, and the hospital carries out a root cause analysis. What is its main focus?
AIdentifying which staff member made the error and should be disciplined
BEstimating the legal costs for the hospital
CFinding the system and process weaknesses that allowed the error
DDeciding whether to tell the family about the error
17.Lab values & electrolytesMedium
A nurse completed the hepatitis B vaccine series. Which result shows protective immunity?
AA positive IgM anti-HBc
BA positive HBsAg test
CAnti-HBs of 10 mIU/mL or more
DA raised ALT level
18.Lab values & electrolytesHard
Four patients had a thyroidectomy earlier today. Which result should the nurse act on first?
ASodium 136 mEq/L on IV fluids after surgery
BGlucose 145 mg/dL (8.0 mmol/L) after surgery
CHemoglobin 12.1 g/dL (121 g/L) after surgery
DCalcium 7.2 mg/dL (1.8 mmol/L) with tingling lips
3Solutions
1.Nursing fundamentals
Answer: D · Voluntary agreement by a patient with capacity, after receiving adequate information
Why this is the answer
Valid consent requires a patient with capacity, enough information about risks, benefits and alternatives, and a free choice. It can be withdrawn at any time.
Answer
D · Voluntary agreement by a patient with capacity, after receiving adequate information
2.Nursing fundamentals
Answer: B · Ask the team whether the observations can safely be done less often
Why this is the answer
Lack of sleep can contribute to delirium. If the patient's scores are stable, the frequency of observations can be reviewed by the team so care is safe but less disruptive.
Answer
B · Ask the team whether the observations can safely be done less often
3.Clinical nursing
Answer: C · The tube bypasses the nose, which normally warms and moistens air
Why this is the answer
The upper airway normally humidifies inspired air. Without it, secretions become thick and may block the tracheostomy tube, so humidification is used.
Answer
C · The tube bypasses the nose, which normally warms and moistens air
4.Clinical nursing
Answer: B · Sudden breathlessness and pleuritic chest pain with tachycardia
Why this is the answer
PE typically presents with sudden dyspnoea, chest pain on breathing, tachycardia, low oxygen saturation and sometimes haemoptysis or collapse.
Answer
B · Sudden breathlessness and pleuritic chest pain with tachycardia
5.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 7.43: within 7.35–7.45
PaCO₂ 31 mmHg: low (35–45)
HCO₃⁻ 20 mmol/L: low (22–26)
Compensation
fully compensated
Answer
fully compensated
6.Arterial blood gas interpretation
Answer: added normal-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 = 138 − (110 + 12) = 16
Delta ratio
(16 − 12)/(24 − 12) = 0.3333
added normal-gap acidosis
Answer
added normal-gap acidosis
7.Clinical assessment scores
Answer: NEWS2 = 2
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 16/min → 0
SpO₂ 95% → 1
on air → 0
SBP 118 mmHg → 0
HR 64/min → 0
alert (A) → 0
T 36.0 °C → 1
Add
NEWS2 = 0 + 1 + 0 + 0 + 0 + 0 + 1 = 2
Answer
NEWS2 = 2
8.Clinical assessment scores
Answer: high risk
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: holds on to furniture → 30
IV therapy or saline lock: yes → 20
gait: normal, bed rest or wheelchair → 0
mental status: overestimates or forgets limits → 15
Add
Morse total = 0 + 15 + 30 + 20 + 0 + 15 = 80
Risk level
80 → high risk
Answer
high risk
9.Enteral & parenteral nutrition calculations
Answer: ΔP = 21.8 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
1.3·50 = 65 g/day
Protein from the feed
60·18 = 1080 mL = 1.08 L
1.08·40 = 43.2 g/day
Shortfall
ΔP = 65 − 43.2 = 21.8 g/day
Answer
ΔP = 21.8 g/day
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 162
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: 25·2000/100 = 500 g
amino acids: 4.25·2000/100 = 85 g
Kilocalories per component
dextrose: 500·3.4 = 1700 kcal
amino acids: 85·4 = 340 kcal
lipid: 250·2 = 500 kcal
Non-protein kcal and nitrogen
NPC = 1700 + 500 = 2200 kcal
N = 85/6.25 = 13.6 g
Ratio
NPC : N = 2200/13.6 = 161.8 ≈ 162 : 1
Answer
NPC : N = 162
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: sinus bradycardia
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: R–R = 30 small boxes, 1500 ÷ 30 ≈ 50 per minute.
2. Rhythm: regular, every R–R is 1.20 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: 0.08 s, narrow (below 0.12 s).
Interpretation
sinus bradycardia
Answer
sinus bradycardia
12.ECG rhythm strip interpretation
Answer: PR interval
Five steps for every strip: 1. rate (300 or 1500 method, or the 6-second method if irregular); 2. rhythm: are the R–R intervals equal; 3. P waves: present, upright in lead II, one before every QRS and all alike; 4. PR interval: 0.12–0.20 s and constant; 5. QRS duration: below 0.12 s. Only after the five steps name the rhythm. Normal sinus rhythm passes all five: 60–100/min, regular, upright P before every QRS, PR 0.12–0.20 s, QRS below 0.12 s.
Five steps
1. Rate: R–R = 24 small boxes, 1500 ÷ 24 ≈ 63 per minute.
2. Rhythm: regular, every R–R is 0.96 s.
3. P waves: upright, one before every QRS, all alike.
4. PR interval: 0.36 s, constant, longer than 0.20 s.
5. QRS: 0.08 s, narrow (below 0.12 s).
First abnormal step
PR interval → first-degree AV block
Answer
PR interval
13.Prioritization & delegation
Answer: D · Helping the patient to the toilet every 2 hours as planned
Why this is the answer
A scheduled toileting round is a routine task that follows the care plan. Scoring fall risk, deciding on interventions and teaching need nursing judgement.
Answer
D · Helping the patient to the toilet every 2 hours as planned
14.Prioritization & delegation
Answer: B · Getting a patient out of bed for the first time after surgery
Why this is the answer
The first time out of bed after surgery the patient may faint or show other unexpected responses, so the RN usually assesses the patient during it. Later walks with a stable patient, daily weights and oral care are routine tasks.
Answer
B · Getting a patient out of bed for the first time after surgery
15.Infection control & patient safety
Answer: D · Lock the brakes and place it close to the bed on the patient’s stronger side
Why this is the answer
Locked brakes stop the chair rolling away during the transfer. Placing it close to the bed on the stronger side lets the patient lead with their strong leg.
Answer
D · Lock the brakes and place it close to the bed on the patient’s stronger side
16.Infection control & patient safety
Answer: C · Finding the system and process weaknesses that allowed the error
Why this is the answer
A root cause analysis looks beyond the individual to the system factors, such as storage, labeling, staffing or workflow, that allowed the error. The aim is to change the system so the error cannot happen again.
Answer
C · Finding the system and process weaknesses that allowed the error
17.Lab values & electrolytes
Answer: C · Anti-HBs of 10 mIU/mL or more
Why this is the answer
An anti-HBs level of at least 10 mIU/mL after vaccination indicates protection. HBsAg and IgM anti-HBc indicate infection, not immunity. Health care workers are often tested after vaccination.Checked against:Hepatitis virus panel · MedlinePlus (NIH) (2024)
Answer
C · Anti-HBs of 10 mIU/mL or more
18.Lab values & electrolytes
Answer: D · Calcium 7.2 mg/dL (1.8 mmol/L) with tingling lips
Why this is the answer
Hypocalcemia after thyroid surgery, from parathyroid injury, can progress to tetany and laryngospasm. Tingling lips are an early sign, so the nurse assesses the airway and Chvostek and Trousseau signs and reports at once. The other results are expected after surgery.Checked against:Calcium Blood Test · MedlinePlus (NIH) (2024)
Answer
D · Calcium 7.2 mg/dL (1.8 mmol/L) with tingling lips