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
A smoker says, "I know I should stop, and I'm thinking about it some time in the next few months." Which stage of change is this?
APrecontemplation
BContemplation
CPreparation
DMaintenance
2.Nursing fundamentalsHard
A patient with dementia keeps getting out of bed at night. What is the best first nursing approach?
AAsk the doctor to prescribe a sedative so the patient sleeps through the night
BLook for an unmet need such as toileting, pain, hunger or thirst
CTie a sheet across the bed to keep the patient in
DRaise the bed rails and leave the patient alone
3.Clinical nursingMedium
Modern wound care generally aims to keep a healing wound bed:
ASoaked in antiseptic solution every day
BCompletely dry and open to the air
CMoist but not wet
DTightly packed with dry gauze
4.Clinical nursingHard
An older patient found on the floor after lying there for many hours has dark brown urine and a very high creatine kinase. What is the main risk?
AA stroke
BHypoglycaemia
CA urinary tract infection from lying in urine
DAcute kidney injury from rhabdomyolysis
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.28, PaCO₂ 20 mmHg (2.7 kPa) and HCO₃⁻ 9 mmol/L. The primary disorder is metabolic acidosis. How far is it compensated? Click your answer.
pH 7.28PaCO₂ 20 mmHg (2.7 kPa)HCO₃⁻ 9 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
At sea level, a practice gas taken on 50% oxygen shows PaO₂ 62 mmHg (8.3 kPa) and PaCO₂ 59 mmHg (7.9 kPa). Use PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 to find the A–a gradient.
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 10/min, SpO₂ 97% on supplemental oxygen, blood pressure 100/60 mmHg, pulse 82/min, alert, temperature 38.4 °C. What is the NEWS2 total score?
RR 10SpO₂ 97%O₂SBP 100HR 82AT 38.4 °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: no; ambulatory aid: none, bed rest or nurse assists; IV therapy or saline lock: no; 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 60 kg patient needs 1.2 g of protein per kg a day. The tube feed contains 40 g of protein per litre and runs at 70 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). A critically ill man is 171 cm tall and weighs 96 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.
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
1sinus rhythm with PVCs
2atrial fibrillation
3normal sinus rhythm
4first-degree AV block
12.ECG rhythm strip interpretationHard
Identify the rhythm on this 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
1atrial fibrillation
2sinus tachycardia
3ventricular tachycardia
4supraventricular tachycardia (SVT)
13.Prioritization & delegationMedium
During a blood transfusion, a patient develops chills, back pain and a fever. What is the nurse’s first action?
AStop the transfusion and keep the IV open with normal saline via new tubing
BSlow the transfusion and recheck in an hour
CFinish the unit quickly through a pressure bag so that the reaction does not last long
DGive an antipyretic and continue the transfusion
14.Prioritization & delegationHard
Which patient is the best choice for the room closest to the nurses’ station?
AA patient admitted for a planned scan, feeling well
BA confused older adult at high risk of falls
CA young adult waiting for discharge tomorrow
DA patient with stable diabetes who walks independently
15.Infection control & patient safetyMedium
A patient with suspected tuberculosis is in a negative-pressure room. Which practice is correct?
ALet visitors enter without any protection
BKeep the door closed except when entering or leaving
CTurn off the room ventilation at night
DKeep the door open so staff can see the patient at all times
16.Infection control & patient safetyHard
A patient sitting in a chair starts to have a generalized seizure. What should the nurse do?
AHold the patient firmly in the chair until the seizure stops
BLeave to get the provider, then return
CPut a padded tongue blade between the teeth to protect the tongue and airway
DEase the patient to the floor, protect the head and turn them on their side
17.Lab values & electrolytesMedium
A nurse completed the hepatitis B vaccine series. Which result shows protective immunity?
AAnti-HBs of 10 mIU/mL or more
BA raised ALT level
CA positive IgM anti-HBc
DA positive HBsAg test
18.Lab values & electrolytesHard
A patient has fatigue, weight gain and constipation. Results: TSH 24 mIU/L, free T4 low, total cholesterol 285 mg/dL (7.4 mmol/L), sodium 131 mEq/L. What is the best interpretation?
AFamilial hypercholesterolemia, unrelated to the thyroid results
BHyperthyroidism, with suppressed thyroid hormone production
CPrimary hypothyroidism, which can raise lipids and lower sodium
DSecondary hypothyroidism from failure of the pituitary gland
3Solutions
1.Nursing fundamentals
Answer: B · Contemplation
Why this is the answer
In the stages-of-change model, contemplation means considering change within about six months without a firm plan. Precontemplation means not thinking about change yet.
Answer
B · Contemplation
2.Nursing fundamentals
Answer: B · Look for an unmet need such as toileting, pain, hunger or thirst
Why this is the answer
Restlessness in dementia often has a cause, such as needing the toilet, pain or being cold. Meeting the need is safer than restraint or sedation, which increase the risk of harm.
Answer
B · Look for an unmet need such as toileting, pain, hunger or thirst
3.Clinical nursing
Answer: C · Moist but not wet
Why this is the answer
A moist wound environment speeds epithelial cell migration and healing. Too much moisture causes maceration, so dressings are chosen to manage exudate.
Answer
C · Moist but not wet
4.Clinical nursing
Answer: D · Acute kidney injury from rhabdomyolysis
Why this is the answer
Prolonged pressure on muscles causes rhabdomyolysis, releasing myoglobin and potassium. Myoglobin can block kidney tubules; treatment includes IV fluids and close monitoring of urine output and electrolytes.
Answer
D · Acute kidney injury from rhabdomyolysis
5.Arterial blood gas interpretation
Answer: partially 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 7.28: acidaemia (below 7.35)
PaCO₂ 20 mmHg: low (35–45)
HCO₃⁻ 9 mmol/L: low (22–26)
Compensation
partially compensated
Answer
partially compensated
6.Arterial blood gas interpretation
Answer: A–a gradient = 220.8 mmHg
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.
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 10/min → 1
SpO₂ 97% → 0
on oxygen → 2
SBP 100 mmHg → 2
HR 82/min → 0
alert (A) → 0
T 38.4 °C → 1
Add
NEWS2 = 1 + 0 + 2 + 2 + 0 + 0 + 1 = 6
Answer
NEWS2 = 6
8.Clinical assessment scores
Answer: low 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: no → 0
ambulatory aid: none, bed rest or nurse assists → 0
IV therapy or saline lock: no → 0
gait: normal, bed rest or wheelchair → 0
mental status: overestimates or forgets limits → 15
Add
Morse total = 0 + 0 + 0 + 0 + 0 + 15 = 15
Risk level
15 → low risk
Answer
low risk
9.Enteral & parenteral nutrition calculations
Answer: ΔP = 27.2 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
1.2·60 = 72 g/day
Protein from the feed
70·16 = 1120 mL = 1.12 L
1.12·40 = 44.8 g/day
Shortfall
ΔP = 72 − 44.8 = 27.2 g/day
Answer
ΔP = 27.2 g/day
10.Enteral & parenteral nutrition calculations
Answer: P = 134 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 = 96/1.71² = 32.83 kg/m²
Ideal body weight (Devine)
171 cm/2.54 = 67.32 in
IBW = 50 + 2.3·(67.32 − 60) = 66.84 kg
Protein goal
BMI 30 to under 40: 2 g per kg of ideal body weight.
P = 2·66.84 = 133.7 ≈ 134 g/day
Answer
P = 134 g/day
11.ECG rhythm strip interpretation
Answer: sinus rhythm with PVCs
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: regular (0.72 s) except for the early beats and the pause after each of them.
3. P waves: upright before every narrow QRS; none before the early wide beats.
4. PR interval: 0.16 s, constant, within 0.12–0.20 s.
5. QRS: 0.08 s in the sinus beats; the early beats are wide (0.14 s) and bizarre, with the T wave pointing the other way.
Interpretation
sinus rhythm with PVCs
Answer
sinus rhythm with PVCs
12.ECG rhythm strip interpretation
Answer: ventricular tachycardia
Ventricular rhythms: ventricular tachycardia is a run of three or more wide (0.12 s or more) complexes in a row at more than 100/min, usually 150–250/min, regular, without related P waves. Ventricular fibrillation is a chaotic, irregular waveform with no identifiable P waves, QRS complexes or T waves and no countable rate. Asystole is an almost flat line with no ventricular activity; a flat line is always confirmed by checking the patient, the leads and the gain and a second lead. In resuscitation guidelines VF and pulseless VT are the shockable rhythms and asystole is not.
Five steps
1. Rate: R–R = 10 small boxes, 1500 ÷ 10 ≈ 150 per minute.
2. Rhythm: regular, every R–R is 0.40 s.
3. P waves: none identifiable.
4. PR interval: not measurable.
5. QRS: 0.16 s, wide (0.12 s or more).
Interpretation
ventricular tachycardia
Answer
ventricular tachycardia
In resuscitation guidelines VF and pulseless VT are the shockable rhythms. This is identification practice only.
13.Prioritization & delegation
Answer: A · Stop the transfusion and keep the IV open with normal saline via new tubing
Why this is the answer
For any suspected transfusion reaction, the nurse stops the transfusion at once, keeps the vein open with normal saline through new tubing and informs the provider and blood bank.
Answer
A · Stop the transfusion and keep the IV open with normal saline via new tubing
14.Prioritization & delegation
Answer: B · A confused older adult at high risk of falls
Why this is the answer
A confused patient at high risk of falls benefits from being close to staff, so they can be observed and helped quickly. The other patients are stable and independent.
Answer
B · A confused older adult at high risk of falls
15.Infection control & patient safety
Answer: B · Keep the door closed except when entering or leaving
Why this is the answer
The door is kept closed so that the airflow into the room is maintained. Visitors are limited and instructed about respiratory protection according to policy.
Answer
B · Keep the door closed except when entering or leaving
16.Infection control & patient safety
Answer: D · Ease the patient to the floor, protect the head and turn them on their side
Why this is the answer
The nurse guides the patient gently to the floor, cushions the head, moves objects away and turns the patient on their side to protect the airway. The nurse stays, times the seizure and calls for help.
Answer
D · Ease the patient to the floor, protect the head and turn them on their side
17.Lab values & electrolytes
Answer: A · 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
A · Anti-HBs of 10 mIU/mL or more
18.Lab values & electrolytes
Answer: C · Primary hypothyroidism, which can raise lipids and lower sodium