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
At what angle is an intramuscular injection given?
A90 degrees
B45 degrees
C15 degrees
D30 degrees
2.Nursing fundamentalsHard
A patient with diabetes has had foot-care teaching. Which statement shows a need for further teaching?
A"I'll check my feet every day, using a mirror if needed."
B"I'll soak my feet in hot water every evening."
C"I'll dry carefully between my toes after washing."
D"I'll wear shoes that fit well and never walk barefoot."
3.Clinical nursingMedium
Which blood result often rises in an upper GI bleed because blood is digested in the gut?
AGlucose
BSodium
CUrea (blood urea nitrogen)
DCalcium
4.Clinical nursingHard
A patient who speaks little English needs to give consent for a procedure. Their 14-year-old child offers to interpret. What is the best action?
AUse gestures and proceed
BArrange a professional interpreter
CLet the child interpret to save time
DAsk the patient to sign the form without explanation
5.Arterial blood gas interpretationMedium
A practice gas shows a metabolic acidosis with HCO₃⁻ 16 mmol/L. Use Winter’s formula to find the expected PaCO₂ (the centre of the range) in mmHg.
HCO₃⁻ 16 mmol/L
PaCO₂ = mmHg
6.Arterial blood gas interpretationHard
A practice gas shows a metabolic alkalosis with HCO₃⁻ 46 mmol/L. Use expected PaCO₂ = 0.7·HCO₃⁻ + 21 to find the expected PaCO₂.
HCO₃⁻ 46 mmol/L
PaCO₂ = mmHg
7.Clinical assessment scoresMedium
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: weak; 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). An adult weighs 115 kg and is 186 cm tall. Calculate the BMI and click the WHO weight category.
Practice exercise (made-up values, not clinical guidance). An 85 kg adult (BMI below 30) needs 30 kcal/kg/day. The tube feed provides 1 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 1500 mL of parenteral nutrition with final concentrations of 15% dextrose and 5% amino acids, plus 500 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.
1500 mLdextrose 15%amino acids 5%lipid 500 mL · 2 kcal/mL
NPC : N =
11.ECG rhythm strip interpretationMedium
This lead II strip shows sinus rhythm with one pause. Measure the pause, the R–R interval across it, in seconds.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
pause = s
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
1ventricular fibrillation
2atrial fibrillation
3ventricular tachycardia
4atrial flutter, 2:1 conduction
13.Prioritization & delegationMedium
A nursing assistant tells the RN that a patient’s IV pump is alarming. What is the best response?
A“I will come and check the pump and the IV site now.”
B“Turn the pump off and on again until it stops.”
C“Increase the rate a little so the alarm clears.”
D“Silence the alarm and I will check it at the end of the shift.”
14.Prioritization & delegationHard
A nursing assistant has twice not reported abnormal vital signs to the RN. What is the RN’s best action?
ATalk to the assistant privately, restate what must be reported and follow up closely
BComplain about the assistant to the patients during care
CStop delegating any tasks to the assistant for the rest of the year
DSay nothing to the assistant and quietly recheck all of the assistant’s vital signs in secret
15.Infection control & patient safetyMedium
During a norovirus outbreak on a ward, which hand hygiene method should staff use after patient care?
AWiping hands on a paper towel only
BAlcohol hand rub only
CWashing with soap and water
DNo hand hygiene if gloves were worn
16.Infection control & patient safetyHard
A competent patient at high risk of falls insists on walking to the bathroom alone. What is the best nursing approach?
AApply wrist restraints so the patient stays in bed
BRemove the patient’s shoes and walking aid so that they cannot walk alone
CTell the patient that walking alone is against hospital law
DExplain the risks, agree on ways to reduce them, respect the decision and document
17.Lab values & electrolytesMedium
How does IV calcium gluconate help a patient with severe hyperkalemia?
AIt stabilizes heart cell membranes without lowering potassium
BIt moves potassium from the blood into the cells
CIt binds potassium in the gut so that it is passed in the stool
DIt increases potassium excretion by the kidneys
18.Lab values & electrolytesHard
Which set of results is most typical of iron-deficiency anemia?
ANormal hemoglobin with a high platelet count only
BHigh hemoglobin and high hematocrit
CLow hemoglobin, large red cells (high MCV) and high ferritin
DLow hemoglobin, small red cells (low MCV) and low ferritin
3Solutions
1.Nursing fundamentals
Answer: A · 90 degrees
Why this is the answer
Intramuscular injections are given at 90 degrees so the needle passes through the skin and fat into the muscle. Intradermal injections use about 10–15 degrees.
Answer
A · 90 degrees
2.Nursing fundamentals
Answer: B · "I'll soak my feet in hot water every evening."
Why this is the answer
People with diabetic neuropathy may not feel heat, and soaking softens the skin, so long hot soaks are avoided. Daily inspection, good footwear and careful drying are correct.
Answer
B · "I'll soak my feet in hot water every evening."
3.Clinical nursing
Answer: C · Urea (blood urea nitrogen)
Why this is the answer
Blood proteins digested in the upper GI tract are absorbed and converted to urea, so urea rises out of proportion to creatinine. Urea is part of the Glasgow-Blatchford bleeding score.
Answer
C · Urea (blood urea nitrogen)
4.Clinical nursing
Answer: B · Arrange a professional interpreter
Why this is the answer
Professional interpreters provide accurate, impartial translation and protect confidentiality. Children and family members should not be used for important clinical discussions such as consent.
Answer
B · Arrange a professional interpreter
5.Arterial blood gas interpretation
Answer: PaCO₂ = 32 mmHg
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.
Winter’s formula
PaCO₂ = 1.5·16 + 8 = 32 mmHg
range: 30–34 mmHg
Answer
PaCO₂ = 32 mmHg
6.Arterial blood gas interpretation
Answer: PaCO₂ = 53.2 mmHg
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
0.7·46 + 21 = 53.2 mmHg
Answer
PaCO₂ = 53.2 mmHg
The rise has a limit: PaCO₂ rarely goes above about 55 mmHg from compensation alone.
7.Clinical assessment scores
Answer: MFS = 55
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: weak → 10
mental status: knows own limits → 0
Add
Morse total = 25 + 0 + 0 + 20 + 10 + 0 = 55
Answer
MFS = 55
8.Clinical assessment scores
Answer: obesity class I
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 = 115/1.86² = 33.24
Category
obesity class I
Answer
obesity class I
9.Enteral & parenteral nutrition calculations
Answer: R = 106 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 = 30·85 = 2550 kcal/day
Daily volume
V = 2550/1 = 2550 mL/day
Pump rate
R = 2550/24 = 106.3 ≈ 106 mL/h
Answer
R = 106 mL/h
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 147
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: 15·1500/100 = 225 g
amino acids: 5·1500/100 = 75 g
Kilocalories per component
dextrose: 225·3.4 = 765 kcal
amino acids: 75·4 = 300 kcal
lipid: 500·2 = 1000 kcal
Non-protein kcal and nitrogen
NPC = 765 + 1000 = 1765 kcal
N = 75/6.25 = 12 g
Ratio
NPC : N = 1765/12 = 147.1 ≈ 147 : 1
Answer
NPC : N = 147
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: pause = 2.32 s
Narrow-complex tachycardia and pauses: supraventricular tachycardia (SVT) is a regular tachycardia at about 150–250/min with narrow QRS complexes; the P waves are usually not visible because they are hidden in the QRS complex or the T wave. Sinus tachycardia in an adult at rest is usually below about 150/min and has a visible P wave before every QRS; atrial flutter with 2:1 conduction often runs at about 150/min and shows sawtooth waves. In sinus arrest the sinus node stops firing for a moment: a pause with no P wave and no QRS whose length is not a whole number of P–P cycles (a pause of exactly two or three cycles points to sinus exit block instead).
Measure
58 small boxes from R to R across the pause
Convert
pause = 58 × 0.04 s = 2.32 s
Compare with P–P
2.32 ÷ 0.96 ≈ 2.4 P–P cycles, not a whole number
Answer
pause = 2.32 s
No P wave appears in the pause, and the pause is not a whole number of P–P cycles: sinus arrest. A pause of exactly two or three cycles would point to sinus exit block.
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: 0.14 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 · “I will come and check the pump and the IV site now.”
Why this is the answer
An alarm may mean an occlusion, air in the line or infiltration. The nurse checks the pump and site; the assistant should not adjust the pump or silence alarms.
Answer
A · “I will come and check the pump and the IV site now.”
14.Prioritization & delegation
Answer: A · Talk to the assistant privately, restate what must be reported and follow up closely
Why this is the answer
The RN gives direct, private feedback, restates the reporting limits and increases supervision. If the problem continues, it is escalated to the manager according to policy.
Answer
A · Talk to the assistant privately, restate what must be reported and follow up closely
15.Infection control & patient safety
Answer: C · Washing with soap and water
Why this is the answer
Norovirus is not reliably killed by alcohol hand rub, so hands are washed with soap and water, which removes it mechanically. Contact precautions and thorough environmental cleaning are also used.
Answer
C · Washing with soap and water
16.Infection control & patient safety
Answer: D · Explain the risks, agree on ways to reduce them, respect the decision and document
Why this is the answer
A competent patient can accept a risk. The nurse explains the danger, offers measures such as a low bed, non-slip footwear, a clear path and a call light, respects the choice and documents the discussion.
Answer
D · Explain the risks, agree on ways to reduce them, respect the decision and document
17.Lab values & electrolytes
Answer: A · 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
A · It stabilizes heart cell membranes without lowering potassium
18.Lab values & electrolytes
Answer: D · Low hemoglobin, small red cells (low MCV) and low ferritin
Why this is the answer
Iron deficiency causes a microcytic anemia (low MCV) with low iron stores (low ferritin). Large red cells suggest vitamin B12 or folate deficiency.Checked against:Ferritin Blood Test · MedlinePlus (NIH) (2025); RBC indices · MedlinePlus (NIH) (2026)
Answer
D · Low hemoglobin, small red cells (low MCV) and low ferritin