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 measure helps prevent deep vein thrombosis in hospital patients?
ARestricting fluids
BCrossing the legs while sitting
CKeeping the patient in bed as long as possible
DEarly mobilisation and leg exercises
2.Nursing fundamentalsHard
A patient on regular paracetamol (acetaminophen) also takes an over-the-counter cold and flu remedy. Why is this a concern?
AThere is no concern, as cold remedies contain no drugs
BMany cold remedies also contain paracetamol, risking liver damage
CParacetamol makes cold remedies cause drowsiness
DCold remedies stop paracetamol from working, so the pain will not be controlled
3.Clinical nursingMedium
Which factor is most likely to slow wound healing?
ASmoking
BA diet rich in protein
CGood blood glucose control
DAdequate fluid intake
4.Clinical nursingHard
A patient after major surgery has a falling blood pressure, rising heart rate and a swollen, tense abdomen, though the wound dressing is dry. What should you suspect?
AInternal bleeding
BUrinary tract infection
CConstipation
DNormal postoperative swelling with no concern
5.Arterial blood gas interpretationMedium
Practice values: Na⁺ 138 mmol/L, glucose 31.4 mmol/L and urea 6.5 mmol/L. Calculate the serum osmolality Osm = 2·Na⁺ + glucose + urea to the nearest whole number.
Na⁺ 138 mmol/Lglucose 31.4 mmol/Lurea 6.5 mmol/L
Osm = mOsm/kg
6.Arterial blood gas interpretationHard
A practice gas shows a respiratory acidosis: pH 7.19, PaCO₂ 75 mmHg (10.0 kPa), HCO₃⁻ 28 mmol/L. Use the rules ‘HCO₃⁻ rises 1 mmol/L per 10 mmHg (acute) or 3.5 mmol/L per 10 mmHg (chronic)’ to classify it. Click your answer.
pH 7.19PaCO₂ 75 mmHg (10.0 kPa)HCO₃⁻ 28 mmol/L
1acute
2chronic
3acute on chronic
7.Clinical assessment scoresMedium
Practice exercise (made-up values, not clinical guidance). A practice patient is assessed with the Braden scale: sensory perception: slightly limited; moisture: constantly moist; activity: chairfast; mobility: no limitation; nutrition: adequate; friction and shear: no apparent problem. Find the Braden total B.
6–23
B =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 14/min, SpO₂ 93% on room air, blood pressure 222/134 mmHg, pulse 98/min, alert, temperature 35.2 °C. Which clinical risk group does the patient fall into? Click it.
Practice exercise (made-up values, not clinical guidance). A 64 kg patient has a fluid goal of 35 mL/kg/day and receives all fluid through a feeding tube. The formula is 81% free water and runs at 75 mL/h for 24 hours a day. The rest of the fluid is given as water flushes every 4 hours. What volume V is each flush? 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 10% dextrose and 3.5% amino acids, plus 100 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 10%amino acids 3.5%lipid 100 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
1first-degree AV block
2sinus bradycardia
3junctional rhythm
4atrial fibrillation
12.ECG rhythm strip interpretationHard
This lead II strip shows a conduction problem between the atria and the ventricles. 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
1second-degree AV block type II
2second-degree AV block type I (Wenckebach)
3third-degree (complete) AV block
4first-degree AV block
13.Prioritization & delegationMedium
A malnourished patient admitted with alcohol use disorder needs IV glucose. Which vitamin is given before or with it?
AVitamin C (ascorbic acid)
BVitamin K (phytonadione)
CVitamin D (calciferol)
DThiamine (vitamin B1)
14.Prioritization & delegationHard
Four laboratory results come back at once. Which one should the nurse report first?
AHemoglobin 6.5 g/dL (65 g/L) in a patient with a GI bleed
BPotassium 3.4 mEq/L in a patient on a diuretic
CCreatinine 1.3 mg/dL in an older adult, unchanged from last week
DGlucose 180 mg/dL after a meal in a patient with diabetes
15.Infection control & patient safetyMedium
When is it appropriate to use the override function on an automated dispensing cabinet to take a drug before pharmacist review?
AAt the start of each shift to save time later
BWhenever the nurse is sure of the dose
COnly in an urgent situation where delay would harm the patient, per policy
DWhenever the pharmacist is slow to review new orders and the patient is waiting
16.Infection control & patient safetyHard
A bag of chemotherapy drug leaks onto the floor. What is the first step?
AWipe it up quickly with paper towels and bare hands
BLeave it to dry, then clean it up at the end of the shift
CPut on the spill kit’s protective equipment and contain the spill
DAsk the cleaner to mop it up with the usual mop
17.Lab values & electrolytesMedium
A woman who is 30 weeks pregnant has a new blood pressure of 152/98 mm Hg. Which urine finding would most support preeclampsia?
AProtein in the urine
BNitrites in the urine
CKetones in the urine
DGlucose in the urine
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
BSecondary hypothyroidism from failure of the pituitary gland
CHyperthyroidism, with suppressed thyroid hormone production
DPrimary hypothyroidism, which can raise lipids and lower sodium
3Solutions
1.Nursing fundamentals
Answer: D · Early mobilisation and leg exercises
Why this is the answer
Moving early, leg exercises, good hydration and, where assessed as appropriate, compression or anticoagulant drugs reduce venous stasis and the risk of thrombosis.
Answer
D · Early mobilisation and leg exercises
2.Nursing fundamentals
Answer: B · Many cold remedies also contain paracetamol, risking liver damage
Why this is the answer
Paracetamol is in many combination products. Taking several at once can push the total over the safe daily maximum and cause liver damage, so patients are taught to check labels.
Answer
B · Many cold remedies also contain paracetamol, risking liver damage
3.Clinical nursing
Answer: A · Smoking
Why this is the answer
Smoking causes vasoconstriction and reduces tissue oxygen, slowing healing and increasing infection risk. Poor nutrition, diabetes, infection and steroids also impair healing.
Answer
A · Smoking
4.Clinical nursing
Answer: A · Internal bleeding
Why this is the answer
Haemodynamic signs of shock with abdominal distension suggest intra-abdominal haemorrhage, even without visible blood loss. Urgent surgical review is required.
Answer
A · Internal bleeding
5.Arterial blood gas interpretation
Answer: Osm = 314 mOsm/kg
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.
Calculated osmolality
Osm = 2·138 + 31.4 + 6.5 = 313.9 ≈ 314 mOsm/kg
Answer
Osm = 314 mOsm/kg
6.Arterial blood gas interpretation
Answer: acute
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 HCO₃⁻
acute: 24 + 1·3.5 = 27.5 mmol/L
chronic: 24 + 3.5·3.5 = 36.25 mmol/L
Compare
measured: 28 mmol/L → acute
Answer
acute
7.Clinical assessment scores
Answer: B = 16
Braden scale: six subscales for pressure-injury risk. Sensory perception, moisture, activity, mobility and nutrition score 1 to 4, from the worst level (1) to no problem (4); friction and shear scores 1 to 3. The total runs from 6 to 23, and a lower total means a higher risk. Common bands: 19–23 not at risk, 15–18 mild risk, 13–14 moderate risk, 10–12 high risk and 9 or below very high risk.
Score each subscale
sensory perception: slightly limited → 3
moisture: constantly moist → 1
activity: chairfast → 2
mobility: no limitation → 4
nutrition: adequate → 3
friction and shear: no apparent problem → 3
Add
Braden total = 3 + 1 + 2 + 4 + 3 + 3 = 16
Answer
B = 16
8.Clinical assessment scores
Answer: high
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 14/min → 0
SpO₂ 93% → 2
on air → 0
SBP 222 mmHg → 3
HR 98/min → 1
alert (A) → 0
T 35.2 °C → 1
Total and red scores
NEWS2 = 0 + 2 + 0 + 3 + 1 + 0 + 1 = 7
At least one parameter scores 3.
Risk group
high
Answer
high
A total of 5 or more calls for an urgent clinical response.
9.Enteral & parenteral nutrition calculations
Answer: V = 130 mL
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.
Fluid goal
35·64 = 2240 mL/day
Free water from the formula
75·24 = 1800 mL
1800·0.81 = 1458 mL
Water still needed
2240 − 1458 = 782 mL/day
Volume per flush
24/4 = 6 flushes
V = 782/6 = 130.3 ≈ 130 mL
Answer
V = 130 mL
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 85
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: 10·1500/100 = 150 g
amino acids: 3.5·1500/100 = 52.5 g
Kilocalories per component
dextrose: 150·3.4 = 510 kcal
amino acids: 52.5·4 = 210 kcal
lipid: 100·2 = 200 kcal
Non-protein kcal and nitrogen
NPC = 510 + 200 = 710 kcal
N = 52.5/6.25 = 8.4 g
Ratio
NPC : N = 710/8.4 = 84.52 ≈ 85 : 1
Answer
NPC : N = 85
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: junctional rhythm
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 = 28 small boxes, 1500 ÷ 28 ≈ 54 per minute.
2. Rhythm: regular, every R–R is 1.12 s.
3. P waves: inverted, just after each QRS.
4. PR interval: not measurable.
5. QRS: 0.06 s, narrow (below 0.12 s).
Interpretation
junctional rhythm
Answer
junctional rhythm
12.ECG rhythm strip interpretation
Answer: second-degree AV block type II
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.
Five steps
1. Rate: 4 QRS complexes in 6 s, × 10 = 40 per minute.
2. Rhythm: the P waves are regular; R–R is regular except for a long pause where a QRS is missing.
3. P waves: upright and regular (P–P 0.88 s, 68 per minute); one P in every 3 is not followed by a QRS.
4. PR interval: constant at 0.16 s in the conducted beats.
5. QRS: 0.08 s, narrow (below 0.12 s).
Interpretation
second-degree AV block type II
Answer
second-degree AV block type II
Type II and third-degree blocks are the ones that can suddenly progress, so textbooks rank them as more serious than type I.
13.Prioritization & delegation
Answer: D · Thiamine (vitamin B1)
Why this is the answer
Thiamine deficiency is common in heavy alcohol use, and giving glucose without thiamine can trigger Wernicke encephalopathy. Thiamine is given before or with glucose.
Answer
D · Thiamine (vitamin B1)
14.Prioritization & delegation
Answer: A · Hemoglobin 6.5 g/dL (65 g/L) in a patient with a GI bleed
Why this is the answer
A hemoglobin of 6.5 g/dL (65 g/L) in a bleeding patient shows severe anemia and may need urgent transfusion. The other results are mildly abnormal or stable.
Answer
A · Hemoglobin 6.5 g/dL (65 g/L) in a patient with a GI bleed
15.Infection control & patient safety
Answer: C · Only in an urgent situation where delay would harm the patient, per policy
Why this is the answer
Pharmacist review checks for allergies, interactions and dosing errors. Overrides are limited to true emergencies and drugs on an approved list, because bypassing review has led to serious errors.
Answer
C · Only in an urgent situation where delay would harm the patient, per policy
16.Infection control & patient safety
Answer: C · Put on the spill kit’s protective equipment and contain the spill
Why this is the answer
Hazardous drug spills are handled with a spill kit, including chemotherapy-tested gloves, a gown and eye protection. The area is secured and the spill is contained, cleaned and disposed of as hazardous waste, then reported.
Answer
C · Put on the spill kit’s protective equipment and contain the spill
17.Lab values & electrolytes
Answer: A · Protein in the urine
Why this is the answer
Preeclampsia is new hypertension after 20 weeks of pregnancy with proteinuria or other signs of organ involvement, such as low platelets, raised liver enzymes or rising creatinine. Proteinuria reflects damage to the glomerular filter.Checked against:Preeclampsia · MedlinePlus (NIH) (2026)
Answer
A · Protein in the urine
18.Lab values & electrolytes
Answer: D · Primary hypothyroidism, which can raise lipids and lower sodium