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 patient says, "I've never seen this tablet before," as the nurse offers it. What should the nurse do?
AStop and recheck the prescription before giving it
BReassure the patient that the tablet is correct and give it
CLeave the tablet on the table for the patient to take later
DGive half the tablet until the doctor visits
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
BCold remedies stop paracetamol from working, so the pain will not be controlled
CMany cold remedies also contain paracetamol, risking liver damage
DParacetamol makes cold remedies cause drowsiness
3.Clinical nursingMedium
Which of these is a non-drug measure that can help relieve pain?
AKeeping the patient awake all night
BTelling the patient that the pain is not real
CRestricting visitors completely
DRepositioning and distraction
4.Clinical nursingHard
During a general anaesthetic, a patient develops a rapidly rising temperature, muscle rigidity and rising carbon dioxide levels. What should be suspected?
ANeuroleptic malignant syndrome from antipsychotics
BA normal response to surgery
CMalignant hyperthermia
DPostoperative infection
5.Arterial blood gas interpretationMedium
A practice gas shows a metabolic acidosis with HCO₃⁻ 10 mmol/L. Use Winter’s formula to find the expected PaCO₂ (the centre of the range) in mmHg.
HCO₃⁻ 10 mmol/L
PaCO₂ = mmHg
6.Arterial blood gas interpretationHard
Practice values: Na⁺ 136, Cl⁻ 111, HCO₃⁻ 12 mmol/L and albumin 20 g/L. Find the albumin-corrected anion gap AGc = AG + 0.25·(40 − albumin).
Practice exercise (made-up values, not clinical guidance). A practice patient is assessed with the Braden scale: sensory perception: no impairment; moisture: rarely moist; activity: chairfast; mobility: slightly limited; nutrition: probably inadequate; friction and shear: problem. Find the Braden total B.
6–23
B =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). An adult weighs 95 kg and is 186 cm tall. Calculate the BMI and click the WHO weight category.
Practice exercise (made-up values, not clinical guidance). A 77 kg patient has a fluid goal of 30 mL/kg/day and receives all fluid through a feeding tube. The formula is 81% free water and runs at 85 mL/h for 24 hours a day. The rest of the fluid is given as water flushes every 6 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 1000 mL of parenteral nutrition with final concentrations of 25% dextrose and 4.25% 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.
1000 mLdextrose 25%amino acids 4.25%lipid 100 mL · 2 kcal/mL
NPC : N =
11.ECG rhythm strip interpretationMedium
This lead II strip shows atrial flutter. How many flutter waves per QRS complex are there (the n of n:1 conduction)?
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
flutter waves per QRS =
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 flutter, 2:1 conduction
2ventricular fibrillation
3torsades de pointes
4supraventricular tachycardia (SVT)
13.Prioritization & delegationMedium
A nurse teaches foot care to a patient with diabetes. Which statement shows a need for further teaching?
A“I will wear shoes that fit well, even at home.”
B“I will dry well between my toes after washing.”
C“I will check the soles of my feet every day with a mirror.”
D“I will soak my feet in hot water every evening.”
14.Prioritization & delegationHard
Which patient finding is unexpected and needs action after a transurethral resection of the prostate with continuous bladder irrigation?
ALight pink urine that becomes clearer over the day
BBright red urine with clots and reduced flow out of the catheter
CMild bladder spasms that ease with the prescribed antispasmodic medication
DA feeling of needing to pass urine despite the catheter
15.Infection control & patient safetyMedium
A patient wants to use their own electric hair dryer in the hospital. What is correct?
AIt can be used straight away if it looks new
BIt can be plugged into an extension lead under the bed
CIt is checked for electrical safety according to hospital policy before use
DIt can be used in the bathroom near the sink if the patient is careful
16.Infection control & patient safetyHard
A nurse teaches a patient with neutropenia about preventing infection at home. Which statement shows a need for further teaching?
A“I will avoid crowds and people who have colds.”
B“I will check my temperature and call if I have a fever.”
C“I will wash my hands often and ask visitors to do the same.”
D“I can clean the cat’s litter box if I wear a face mask.”
17.Lab values & electrolytesMedium
How should a blood sample for serum ammonia be handled?
APlaced on ice and sent to the laboratory at once
BShaken firmly to mix it before it is sent away
CKept warm and sent with the next routine batch
DLeft at room temperature for several hours first
18.Lab values & electrolytesHard
A patient with a large, fast-growing lymphoma will start chemotherapy tomorrow. Which plan best prevents tumor lysis syndrome?
ACalcium supplements and a high-phosphate diet during treatment
BFluid restriction and a high-potassium diet before the treatment
CNo special measures, because the risk starts only after a week
DIV hydration, a uric acid-lowering drug and frequent electrolytes
3Solutions
1.Nursing fundamentals
Answer: A · Stop and recheck the prescription before giving it
Why this is the answer
A patient questioning a medicine may be a sign of an error. The nurse holds the dose, checks the prescription and the drug and explains before giving it.
Answer
A · Stop and recheck the prescription before giving it
2.Nursing fundamentals
Answer: C · 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
C · Many cold remedies also contain paracetamol, risking liver damage
3.Clinical nursing
Answer: D · Repositioning and distraction
Why this is the answer
Positioning, heat or cold where safe, relaxation, distraction and explanation can all reduce pain alongside analgesics.
Answer
D · Repositioning and distraction
4.Clinical nursing
Answer: C · Malignant hyperthermia
Why this is the answer
Malignant hyperthermia is a hypermetabolic reaction triggered by volatile anaesthetics or suxamethonium (succinylcholine) in susceptible people. It is treated urgently with dantrolene, cooling and stopping the trigger.
Answer
C · Malignant hyperthermia
5.Arterial blood gas interpretation
Answer: PaCO₂ = 23 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 = 1.5·10 + 8 = 23 mmHg
range: 21–25 mmHg
Answer
PaCO₂ = 23 mmHg
6.Arterial blood gas interpretation
Answer: AGc = 18 mmol/L
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 = 136 − (111 + 12) = 13
Correction for albumin
13 + 0.25·(40 − 20) = 18 mmol/L
Answer
AGc = 18 mmol/L
Above about 12 after correction: a high anion gap.
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: no impairment → 4
moisture: rarely moist → 4
activity: chairfast → 2
mobility: slightly limited → 3
nutrition: probably inadequate → 2
friction and shear: problem → 1
Add
Braden total = 4 + 4 + 2 + 3 + 2 + 1 = 16
Answer
B = 16
8.Clinical assessment scores
Answer: overweight
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 = 95/1.86² = 27.46
Category
overweight
Answer
overweight
9.Enteral & parenteral nutrition calculations
Answer: V = 164 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
30·77 = 2310 mL/day
Free water from the formula
85·24 = 2040 mL
2040·0.81 = 1652 mL
Water still needed
2310 − 1652 = 657.6 mL/day
Volume per flush
24/6 = 4 flushes
V = 657.6/4 = 164.4 ≈ 164 mL
Answer
V = 164 mL
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 154
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: 25·1000/100 = 250 g
amino acids: 4.25·1000/100 = 42.5 g
Kilocalories per component
dextrose: 250·3.4 = 850 kcal
amino acids: 42.5·4 = 170 kcal
lipid: 100·2 = 200 kcal
Non-protein kcal and nitrogen
NPC = 850 + 200 = 1050 kcal
N = 42.5/6.25 = 6.8 g
Ratio
NPC : N = 1050/6.8 = 154.4 ≈ 154 : 1
Answer
NPC : N = 154
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: flutter waves per QRS = 2
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.
Flutter waves
F–F = 5 small boxes = 0.20 s → 1500 ÷ 5 = 300 per minute
QRS complexes
R–R = 10 small boxes = 0.40 s → 1500 ÷ 10 = 150 per minute
conduction ratio = 300 ÷ 150 = 2:1
Answer
flutter waves per QRS = 2
12.ECG rhythm strip interpretation
Answer: torsades de pointes
More ventricular rhythms: torsades de pointes is a polymorphic ventricular tachycardia, usually 150–250/min, in which the wide complexes change in height and twist around the baseline, pointing up for a few beats and then down. Textbooks link it to a prolonged QT interval, and magnesium sulfate is the drug resuscitation guidelines name for it. An idioventricular rhythm is a ventricular escape rhythm: regular, wide QRS (0.12 s or more), no P waves, at 20–40/min (an accelerated idioventricular rhythm runs at 40–100/min). Monomorphic VT has identical wide complexes at more than 100/min. VF is chaotic, without any repeating complex.
Five steps
1. Rate: very fast, the complexes are about 7 small boxes apart (about 214 per minute).
2. Rhythm: fast and roughly regular, but the height and direction of the complexes change in a repeating spindle pattern.
3. P waves: none identifiable.
4. PR interval: not measurable.
5. QRS: wide and polymorphic; the complexes twist around the baseline, pointing up for a few beats and then down.
Interpretation
torsades de pointes
Answer
torsades de pointes
Torsades de pointes is a polymorphic VT linked to a prolonged QT interval. This is identification practice only.
13.Prioritization & delegation
Answer: D · “I will soak my feet in hot water every evening.”
Why this is the answer
Neuropathy can stop the patient feeling heat, so hot soaks can cause burns, and long soaking dries the skin. Daily checks, careful drying and well-fitting shoes are correct.
Answer
D · “I will soak my feet in hot water every evening.”
14.Prioritization & delegation
Answer: B · Bright red urine with clots and reduced flow out of the catheter
Why this is the answer
Bright red urine with clots suggests arterial bleeding and can block the catheter, causing bladder distension. Light pink urine, urgency and mild spasms are common after this operation.
Answer
B · Bright red urine with clots and reduced flow out of the catheter
15.Infection control & patient safety
Answer: C · It is checked for electrical safety according to hospital policy before use
Why this is the answer
Electrical items from home can be faulty and cause shocks or fires. Policies usually require them to be inspected before use, and extension cords near patients are avoided.
Answer
C · It is checked for electrical safety according to hospital policy before use
16.Infection control & patient safety
Answer: D · “I can clean the cat’s litter box if I wear a face mask.”
Why this is the answer
Immunocompromised patients should avoid cleaning litter boxes and other animal waste, because of organisms such as Toxoplasma. Another person should do it. The other statements are correct.
Answer
D · “I can clean the cat’s litter box if I wear a face mask.”
17.Lab values & electrolytes
Answer: A · Placed on ice and sent to the laboratory at once
Why this is the answer
Ammonia can rise in a standing sample as red cells and proteins break down. The sample is usually placed on ice and analyzed promptly to avoid a falsely high result.
Answer
A · Placed on ice and sent to the laboratory at once
18.Lab values & electrolytes
Answer: D · IV hydration, a uric acid-lowering drug and frequent electrolytes
Why this is the answer
Prevention includes aggressive IV hydration, drugs such as allopurinol or rasburicase to lower uric acid, and frequent monitoring of potassium, phosphate, calcium, uric acid and creatinine. Tumor lysis usually begins within 1–3 days of starting treatment.Checked against:Uric Acid Test · MedlinePlus (NIH) (2026)
Answer
D · IV hydration, a uric acid-lowering drug and frequent electrolytes