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
While being helped to eat, a patient with dysphagia coughs and their voice sounds wet and gurgly. What should the nurse do?
AStop feeding and report for a swallowing assessment
BLie the patient flat to rest
CFeed more quickly so the meal is finished before they tire
DGive a drink of water to wash the food down
2.Nursing fundamentalsHard
A patient standing for the first time after surgery becomes pale, sweaty and dizzy. What should the nurse do first?
AHelp the patient sit or lie down safely
BEncourage the patient to keep walking to build strength
CGive the patient a sugary drink while standing
DLeave the patient standing and fetch the blood pressure machine
3.Clinical nursingMedium
A patient says they are "allergic" to codeine because it made them constipated. How should this be recorded?
AAs a side effect or intolerance, not a true allergy
BAs a severe anaphylactic allergy to all opioids
CIt should not be recorded at all
DAs an allergy to all painkillers
4.Clinical nursingHard
A patient going home with a leg cast is taught about cast care. Which statement shows a need for further teaching?
A"I will keep the cast dry."
B"I will keep my leg raised on pillows for the first few days."
C"I can push a knitting needle down the cast to scratch an itch."
D"I will come back if my toes go numb or turn blue."
5.Arterial blood gas interpretationMedium
A practice gas shows a metabolic acidosis with HCO₃⁻ 6 mmol/L. Use Winter’s formula to find the expected PaCO₂ (the centre of the range) in mmHg.
HCO₃⁻ 6 mmol/L
PaCO₂ = mmHg
6.Arterial blood gas interpretationHard
A practice gas shows pH 7.31, PaCO₂ 31 mmHg (4.1 kPa) and HCO₃⁻ 15 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 8, with E2 and V2. What motor score M was recorded, and which response does it describe? Give the number.
GCS 8E2V2
M =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). An adult weighs 82 kg and is 193 cm tall. Calculate the BMI and click the WHO weight category.
Practice exercise (made-up values, not clinical guidance). A 71 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 75 mL/h for 20 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). Over 24 hours a patient receives 2000 mL of parenteral nutrition with final concentrations of 12.5% dextrose and 3.5% amino acids, plus 100 mL of 20% lipid emulsion (2 kcal/mL). Find the total energy E the patient receives in kcal per day. Round to the nearest whole number.
2000 mLdextrose 12.5%amino acids 3.5%lipid 100 mL · 2 kcal/mL
E = kcal/day
11.ECG rhythm strip interpretationMedium
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 lead II strip shows an AV block, so the atria and the ventricles beat at different rates. Measure the P–P interval and find the atrial rate in beats per minute (1500 method, whole number).
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
atrial rate = bpm
13.Prioritization & delegationMedium
Which patient should the nurse see first?
AA patient with type 2 diabetes asking about the diet
BA patient with long-standing rheumatoid arthritis and the usual morning joint stiffness
CA patient with chronic kidney disease due for dialysis tomorrow
DA patient with new slurred speech and a facial droop that started 30 minutes ago
14.Prioritization & delegationHard
A patient who is 7 weeks pregnant has one-sided lower abdominal pain, pain in the shoulder tip, a heart rate of 120/min and a blood pressure of 88/54 mmHg. What is most likely?
AA ruptured ectopic pregnancy
BA urinary tract infection
CSevere morning sickness
DA normal early pregnancy
15.Infection control & patient safetyMedium
An infusion pump’s drug library warns that the programmed dose is above the safe limit. What should the nurse do?
AContinue the infusion and recheck the pump at the end of the shift
BSwitch off the drug library for this infusion
CRecheck the order, the calculation and the pump settings first
DOverride the alert, because pump alerts are often wrong
16.Infection control & patient safetyHard
A patient who speaks little English is being discharged with new medications. The patient’s 12-year-old child offers to interpret. What should the nurse do?
AGive written instructions in English only
BLet the child interpret, because the family prefers it
CUse simple English and many hand gestures
DUse a professional medical interpreter
17.Lab values & electrolytesMedium
A patient receiving chemotherapy has an ANC of 300/µL and a new temperature of 38.3 °C (100.9 °F). What should the nurse do first?
AGive acetaminophen (paracetamol) and recheck the temperature in 4 hours
BRemove extra blankets and offer a tepid sponge bath
CEncourage oral fluids and record the fever in the chart
DReport it at once so cultures and antibiotics start quickly
18.Lab values & electrolytesHard
On the evening after surgery, a patient’s hemoglobin has fallen from 12.5 g/dL to 8.1 g/dL (125 to 81 g/L), and the heart rate is 118/min. What is the most likely problem?
ABleeding
BDehydration
CNormal dilution after surgery that needs no action
DAn improving condition
3Solutions
1.Nursing fundamentals
Answer: A · Stop feeding and report for a swallowing assessment
Why this is the answer
Coughing, choking and a wet voice during meals suggest food or drink is entering the airway. Feeding stops, the patient sits upright and a speech and language therapist assesses them.
Answer
A · Stop feeding and report for a swallowing assessment
2.Nursing fundamentals
Answer: A · Help the patient sit or lie down safely
Why this is the answer
These signs suggest postural hypotension and a risk of fainting. The nurse lowers the patient safely first, then checks blood pressure and pulse and reports the finding.
Answer
A · Help the patient sit or lie down safely
3.Clinical nursing
Answer: A · As a side effect or intolerance, not a true allergy
Why this is the answer
Constipation is a predictable side effect of opioids, not an immune response. Recording it accurately avoids withholding useful medicines while still noting the patient's experience.
Answer
A · As a side effect or intolerance, not a true allergy
4.Clinical nursing
Answer: C · "I can push a knitting needle down the cast to scratch an itch."
Why this is the answer
Pushing objects under a cast can injure the skin and cause infection or pressure sores. Elevation, keeping the cast dry and reporting numbness, colour change or increasing pain are correct.
Answer
C · "I can push a knitting needle down the cast to scratch an itch."
5.Arterial blood gas interpretation
Answer: PaCO₂ = 17 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 = 1.5·6 + 8 = 17 mmHg
range: 15–19 mmHg
Answer
PaCO₂ = 17 mmHg
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 + 15) = 24
Delta ratio
(24 − 12)/(24 − 15) = 1.333
pure high-gap acidosis
Answer
pure high-gap acidosis
7.Clinical assessment scores
Answer: M = 4
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 = 8 − 2 − 2 = 4
M4: withdraws the limb from pressure (normal flexion)
Answer
M = 4
8.Clinical assessment scores
Answer: healthy weight
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 = 82/1.93² = 22.01
Category
healthy weight
Answer
healthy weight
9.Enteral & parenteral nutrition calculations
Answer: ΔP = 25.2 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
1.2·71 = 85.2 g/day
Protein from the feed
75·20 = 1500 mL = 1.5 L
1.5·40 = 60 g/day
Shortfall
ΔP = 85.2 − 60 = 25.2 g/day
Answer
ΔP = 25.2 g/day
10.Enteral & parenteral nutrition calculations
Answer: E = 1330 kcal/day
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: 12.5·2000/100 = 250 g
amino acids: 3.5·2000/100 = 70 g
Kilocalories per component
dextrose: 250·3.4 = 850 kcal
amino acids: 70·4 = 280 kcal
lipid: 100·2 = 200 kcal
Total energy
E = 850 + 280 + 200 = 1330 kcal/day
Answer
E = 1330 kcal/day
11.ECG rhythm strip interpretation
Answer: QTc = 0.512 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 = 12 × 0.04 = 0.48 s
RR = 22 × 0.04 = 0.88 s
Bazett’s formula
QTc = 0.48/√0.88 = 0.48/0.9381 = 0.512 s
Answer
QTc = 0.512 s
Above 0.50 s: markedly prolonged. (512 ms)
12.ECG rhythm strip interpretation
Answer: atrial rate = 75 bpm
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.
Atrial rate
P–P = 20 small boxes = 0.80 s → 1500 ÷ 20 = 75 ≈ 75 per minute
Ventricular rate
R–R = 40 small boxes = 1.60 s → 1500 ÷ 40 = 37.5 ≈ 38 per minute
Answer
atrial rate = 75 bpm
Answer
atrial rate = 75 bpm
2:1 AV block: every second P wave is not conducted, so the atrial rate is twice the ventricular rate.
13.Prioritization & delegation
Answer: D · A patient with new slurred speech and a facial droop that started 30 minutes ago
Why this is the answer
Sudden slurred speech and facial droop suggest a stroke, and treatment depends on time. The others have chronic, stable problems that can wait.
Answer
D · A patient with new slurred speech and a facial droop that started 30 minutes ago
14.Prioritization & delegation
Answer: A · A ruptured ectopic pregnancy
Why this is the answer
A ruptured ectopic pregnancy causes internal bleeding, with abdominal pain, shoulder-tip pain and signs of shock. It is a surgical emergency.
Answer
A · A ruptured ectopic pregnancy
15.Infection control & patient safety
Answer: C · Recheck the order, the calculation and the pump settings first
Why this is the answer
Smart pump limits are set to catch programming and calculation errors. The nurse checks the order, the concentration, the dose and the rate before deciding whether an override is truly appropriate.
Answer
C · Recheck the order, the calculation and the pump settings first
16.Infection control & patient safety
Answer: D · Use a professional medical interpreter
Why this is the answer
Professional medical interpreters reduce errors and protect privacy. Children and other family members may translate wrongly, leave things out or be placed in a difficult position.
Answer
D · Use a professional medical interpreter
17.Lab values & electrolytes
Answer: D · Report it at once so cultures and antibiotics start quickly
Why this is the answer
Neutropenic fever is a medical emergency, because infection can progress to sepsis rapidly without the usual signs of inflammation. Blood cultures are taken and broad-spectrum antibiotics are started promptly as prescribed.Checked against:Watch Out for Fever · CDC (2024); What You Need to Know: Neutropenia and Risk for Infection · CDC
Answer
D · Report it at once so cultures and antibiotics start quickly
18.Lab values & electrolytes
Answer: A · Bleeding
Why this is the answer
A fall of more than 4 g/dL with a fast heart rate suggests ongoing blood loss. The nurse assesses the wound and drains, monitors the vital signs and escalates urgently. Some dilution from IV fluids is common, but not this much, and not with tachycardia.Checked against:Hemoglobin Test · MedlinePlus (NIH) (2024)