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
Which early warning sign often appears first when a patient's condition worsens?
ALower heart rate
BImproving appetite
CA rising respiratory rate
DA falling body temperature
2.Nursing fundamentalsHard
Which patient should the nurse see first?
AA patient who is asking for help to walk to the toilet now
BA patient with a pain score of 3/10 whose analgesia is due in an hour
CA postoperative patient with SpO₂ 89% on air and a respiratory rate of 28
DA patient who is waiting for their discharge letter and medicines
3.Clinical nursingMedium
What should the nurse regularly check for a patient with a syringe driver?
AOnly the patient's weight, measured once a week on the same scales
BOnly that the battery is charged and the device is switched on
CNothing, once the syringe driver is running
DThe infusion site, the rate and volume remaining, and the patient's symptoms
4.Clinical nursingHard
Which feature best distinguishes delirium from dementia?
ADementia always causes visual hallucinations
BDelirium only affects people under 50, while dementia affects older people
CDelirium is permanent, while dementia is reversible
DDelirium starts suddenly and fluctuates, while dementia develops gradually
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.43, PaCO₂ 59 mmHg (7.9 kPa) and HCO₃⁻ 38 mmol/L. The primary disorder is metabolic alkalosis. How far is it compensated? Click your answer.
pH 7.43PaCO₂ 59 mmHg (7.9 kPa)HCO₃⁻ 38 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
A practice gas shows pH 7.32, PaCO₂ 36 mmHg (4.8 kPa) and HCO₃⁻ 18 mmol/L, with Na⁺ 134 and Cl⁻ 95 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 chart records GCS 4, with E1 and V2. What motor score M was recorded, and which response does it describe? Give the number.
GCS 4E1V2
M =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). An adult weighs 47 kg and is 174 cm tall. Calculate the BMI and click the WHO weight category.
Practice exercise (made-up values, not clinical guidance). A 79 kg adult (BMI below 30) needs 35 kcal/kg/day. The tube feed provides 1.5 kcal/mL and runs by pump for 16 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). A critically ill woman is 170 cm tall and weighs 97 kg. The practice protocol gives 2 g of protein per kg of ideal body weight (Devine) per day if the BMI is 30 to under 40 kg/m², and 2.5 g/kg of ideal body weight per day if the BMI is 40 kg/m² or more. Find the protein goal P in g/day. Round to the nearest whole number.
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
This patient has a pacemaker. Interpret the 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
1paced rhythm, failure to capture
2idioventricular rhythm
3sinus rhythm with wide QRS
4dual-chamber (AV) paced rhythm
13.Prioritization & delegationMedium
A nurse sees a nursing assistant leave a confused patient’s bed in the highest position after care. What should the nurse do?
ALeave it because the patient is asleep
BLower the bed now and remind the assistant why it matters
CAsk the family to lower the bed when they next visit
DWrite it in the assistant’s yearly review only
14.Prioritization & delegationHard
After a head injury, a patient passes large amounts of very dilute urine, is thirsty and has a rising serum sodium. Which condition is most likely?
ASIADH
BDiabetes insipidus
CAcute kidney injury with oliguria
DDiabetic ketoacidosis
15.Infection control & patient safetyMedium
A nurse pours sterile saline into a bowl on a sterile field. Which technique is correct?
APour from below the level of the field to reduce splashing
BHold the bottle with the label in the palm and pour without touching the bowl
CRest the lip of the bottle on the edge of the bowl so that the saline does not splash
DReach across the field to fill the bowl at the far side
16.Infection control & patient safetyHard
A nurse has raised a safety concern about an order with the prescriber, who dismissed it without addressing it. What should the nurse do next?
AState the concern clearly a second time and, if still unresolved, use the chain of command
BCarry out the order as written, because the prescriber has heard the concern
CRefuse to care for the patient for the rest of the shift until the prescriber apologizes
DDiscuss the concern with the patient and let them decide
17.Lab values & electrolytesMedium
A patient’s hemoglobin is 7.8 g/dL (78 g/L). Which findings would the nurse expect?
AHeadache, nosebleeds and a red face
BItching, yellow skin and dark urine
CFatigue, pallor, a fast heart rate and breathlessness on exertion
DA slow heart rate, flushed skin and a high blood pressure
18.Lab values & electrolytesHard
A patient with right upper abdominal pain from gallstones now has jaundice, a total bilirubin of 4.8 mg/dL (82 µmol/L) and a raised ALP. What is the most likely cause?
AUncomplicated gallbladder inflammation
BGilbert syndrome triggered by pain
CHemolysis caused by the gallstones
DA stone blocking the common bile duct
3Solutions
1.Nursing fundamentals
Answer: C · A rising respiratory rate
Why this is the answer
Tachypnoea is one of the earliest and most sensitive signs of deterioration and scores highly in early warning systems such as NEWS2.
Answer
C · A rising respiratory rate
2.Nursing fundamentals
Answer: C · A postoperative patient with SpO₂ 89% on air and a respiratory rate of 28
Why this is the answer
Low saturation with a high respiratory rate shows a breathing problem that could worsen quickly. The other needs are real but not urgent.
Answer
C · A postoperative patient with SpO₂ 89% on air and a respiratory rate of 28
3.Clinical nursing
Answer: D · The infusion site, the rate and volume remaining, and the patient's symptoms
Why this is the answer
Nurses check that the infusion is running as planned, the site has no redness or swelling, and the symptoms are controlled. Problems are acted on quickly to avoid distress.
Answer
D · The infusion site, the rate and volume remaining, and the patient's symptoms
4.Clinical nursing
Answer: D · Delirium starts suddenly and fluctuates, while dementia develops gradually
Why this is the answer
Delirium develops over hours to days, with fluctuating attention and consciousness, and is often reversible when the cause is treated. Dementia is a gradual, progressive decline. Patients with dementia are at higher risk of delirium.
Answer
D · Delirium starts suddenly and fluctuates, while dementia develops gradually
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 59 mmHg: high (35–45)
HCO₃⁻ 38 mmol/L: high (22–26)
Compensation
Clinically, also check the expected compensation: for a metabolic alkalosis PaCO₂ ≈ 0.7·HCO₃⁻ + 21 = 45.6–49.6 mmHg, so the measured 59 mmHg points to an additional respiratory acidosis (a mixed disorder). The answer above is the ROME exam classification.
fully compensated
Answer
fully compensated
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 = 134 − (95 + 18) = 21
Delta ratio
(21 − 12)/(24 − 18) = 1.5
pure high-gap acidosis
Answer
pure high-gap acidosis
7.Clinical assessment scores
Answer: M = 1
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.
Motor score
M = 4 − 1 − 2 = 1
M1: no movement at all
Answer
M = 1
8.Clinical assessment scores
Answer: underweight
Body mass index: BMI = weight (kg)/height (m)², with the height converted to metres first. With pounds and inches, BMI = 703 × weight (lb)/height (in)². WHO adult categories: below 18.5 underweight, 18.5–24.9 healthy weight, 25.0–29.9 overweight, 30.0–34.9 obesity class I, 35.0–39.9 obesity class II and 40 or more obesity class III.
BMI
BMI = 47/1.74² = 15.52
Category
underweight
Answer
underweight
9.Enteral & parenteral nutrition calculations
Answer: R = 115 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 = 35·79 = 2765 kcal/day
Daily volume
V = 2765/1.5 = 1843 mL/day
Pump rate
R = 1843/16 = 115.2 ≈ 115 mL/h
Answer
R = 115 mL/h
10.Enteral & parenteral nutrition calculations
Answer: P = 123 g/day
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. Obesity in critical illness (ASPEN/SCCM 2016): BMI = weight/height² (kg/m²). The protein goal is 2 g/kg of ideal body weight per day for BMI 30–40 and up to 2.5 g/kg of ideal body weight per day for BMI 40 and above. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Body mass index
BMI = 97/1.7² = 33.56 kg/m²
Ideal body weight (Devine)
170 cm/2.54 = 66.93 in
IBW = 45.5 + 2.3·(66.93 − 60) = 61.44 kg
Protein goal
BMI 30 to under 40: 2 g per kg of ideal body weight.
P = 2·61.44 = 122.9 ≈ 123 g/day
Answer
P = 123 g/day
11.ECG rhythm strip interpretation
Answer: QTc = 0.502 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 = 11.5 × 0.04 = 0.46 s
RR = 21 × 0.04 = 0.84 s
Bazett’s formula
QTc = 0.46/√0.84 = 0.46/0.9165 = 0.502 s
Answer
QTc = 0.502 s
Above 0.50 s: markedly prolonged. (502 ms)
12.ECG rhythm strip interpretation
Answer: dual-chamber (AV) paced rhythm
Paced rhythms: a pacemaker impulse shows as a narrow vertical pacing spike. After a ventricular spike the QRS is wide (0.12 s or more), because the impulse spreads from the lead through the muscle instead of the conduction system; with right-ventricular pacing it is often mostly negative in lead II. A spike before each P wave means atrial pacing, and a dual-chamber (AV) pacemaker shows an atrial spike and a P wave, then, after the programmed AV delay, a ventricular spike and a wide QRS. Capture means every spike is followed by a depolarisation. Failure to capture is a spike without a P wave or QRS after it; failure to sense (spikes that ignore the patient’s own beats) and failure to pace (no spike when one is due) are the other classic malfunctions.
Five steps
1. Rate: R–R = 25 small boxes, 1500 ÷ 25 ≈ 60 per minute.
2. Rhythm: regular, every R–R is 1.00 s.
3. P waves: each P wave follows its own pacing spike (atrial pacing).
4. AV interval: the second spike comes 0.18 s after the first one (the programmed AV delay).
5. QRS: 0.14 s, wide, right after the second spike (ventricular pacing).
Interpretation
dual-chamber (AV) paced rhythm
Answer
dual-chamber (AV) paced rhythm
The paced QRS is wide by nature; do not call it a bundle branch block or a ventricular rhythm.
13.Prioritization & delegation
Answer: B · Lower the bed now and remind the assistant why it matters
Why this is the answer
A high bed increases the risk of a serious fall, so the nurse corrects it at once and gives brief, clear feedback. Leaving it or delaying feedback leaves the patient at risk.
Answer
B · Lower the bed now and remind the assistant why it matters
14.Prioritization & delegation
Answer: B · Diabetes insipidus
Why this is the answer
Damage to the pituitary or hypothalamus can stop the release of antidiuretic hormone, causing diabetes insipidus. The patient loses water, so urine is dilute and sodium rises; SIADH causes the opposite.
Answer
B · Diabetes insipidus
15.Infection control & patient safety
Answer: B · Hold the bottle with the label in the palm and pour without touching the bowl
Why this is the answer
The nurse pours from a little height without touching the sterile bowl, avoiding splashes that would wet the field. Holding the label in the palm keeps it readable and free of drips.
Answer
B · Hold the bottle with the label in the palm and pour without touching the bowl
16.Infection control & patient safety
Answer: A · State the concern clearly a second time and, if still unresolved, use the chain of command
Why this is the answer
The two-challenge rule says the concern is voiced at least twice to make sure it was heard. If it is still not addressed, the nurse escalates through the chain of command rather than acting against the patient’s safety.
Answer
A · State the concern clearly a second time and, if still unresolved, use the chain of command
17.Lab values & electrolytes
Answer: C · Fatigue, pallor, a fast heart rate and breathlessness on exertion
Why this is the answer
Anemia reduces oxygen delivery. The heart beats faster to compensate, and the patient feels tired and breathless with activity and looks pale. Severe anemia can cause chest pain in people with heart disease.Checked against:Anemia · MedlinePlus (NIH) (2026)
Answer
C · Fatigue, pallor, a fast heart rate and breathlessness on exertion
18.Lab values & electrolytes
Answer: D · A stone blocking the common bile duct
Why this is the answer
A gallstone in the common bile duct (choledocholithiasis) obstructs bile flow, raising conjugated bilirubin and ALP. Fever with jaundice and pain suggests cholangitis, an emergency. Simple cholecystitis usually causes only mild liver test changes.Checked against:Choledocholithiasis · MedlinePlus (NIH) (2025); Cholangitis · MedlinePlus (NIH) (2026)