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 bedbound patient who has not opened their bowels for a week now has liquid stool leaking constantly. What should the nurse suspect?
AA side effect of drinking too much water
BFaecal impaction with overflow
CNormal bowel function returning
DAn infection that needs antidiarrhoeal drugs at once
2.Nursing fundamentalsHard
Why is heat usually avoided on a fresh soft-tissue injury during the first day?
AIt widens blood vessels and can increase swelling and bleeding
BIt narrows blood vessels and reduces blood flow to the injury
CIt numbs the area so the patient cannot feel pain
DIt makes the muscles weaker for several weeks
3.Clinical nursingMedium
Before giving a beta-blocker, which observation is most important to check?
ABowel movements
BBlood glucose only
CHeart rate and blood pressure
DTemperature only
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?
APostoperative infection
BMalignant hyperthermia
CA normal response to surgery
DNeuroleptic malignant syndrome from antipsychotics
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.50, PaCO₂ 24 mmHg (3.2 kPa) and HCO₃⁻ 18 mmol/L. The primary disorder is respiratory alkalosis. How far is it compensated? Click your answer.
pH 7.50PaCO₂ 24 mmHg (3.2 kPa)HCO₃⁻ 18 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
Practice values: Na⁺ 141, Cl⁻ 111, HCO₃⁻ 14 mmol/L and albumin 36 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: completely limited; moisture: constantly moist; activity: chairfast; mobility: no limitation; nutrition: very poor; friction and shear: potential problem. Find the Braden total B.
6–23
B =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). A practice patient is assessed with the Braden scale: sensory perception: very limited; moisture: occasionally moist; activity: walks occasionally; mobility: no limitation; nutrition: very poor; friction and shear: potential problem. Use the bands 19–23 not at risk, 15–18 mild, 13–14 moderate, 10–12 high and 9 or below very high. Click the risk level.
Practice exercise (made-up values, not clinical guidance). Use the Devine formula to find the ideal body weight IBW of a woman who is 177 cm tall (1 in = 2.54 cm). Round to one decimal place.
Practice exercise (made-up values, not clinical guidance). Over 24 hours a patient receives 1800 mL of parenteral nutrition with final concentrations of 25% dextrose and 4.25% amino acids, plus 250 mL of 10% lipid emulsion (1.1 kcal/mL). Find the total energy E the patient receives in kcal per day. Round to the nearest whole number.
1800 mLdextrose 25%amino acids 4.25%lipid 250 mL · 1.1 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
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
1supraventricular tachycardia (SVT)
2torsades de pointes
3idioventricular rhythm
4ventricular fibrillation
13.Prioritization & delegationMedium
A patient has heart failure. Which instruction about daily weights is best to give the nursing assistant?
A“Weigh him each morning before breakfast, on the same scale, and tell me the result.”
B“Only weigh him if his ankles look more swollen than they did yesterday afternoon.”
C“Weigh him after lunch, fully dressed, with his shoes on.”
D“Weigh him at any time today, on whichever scale is free.”
14.Prioritization & delegationHard
After handover on a medical unit, which patient should the nurse see first?
ADeep vein thrombosis on a heparin infusion, aPTT in the target range
BDay 2 after a hernia repair, pain 6/10, oral analgesic due in 20 minutes, wants it now
DPneumonia on 2 L/min oxygen, SpO₂ 93%, talking in full sentences
15.Infection control & patient safetyMedium
Hair must be removed from a planned surgical site. Which method reduces the risk of surgical site infection?
AUsing wax strips on the morning of surgery
BClipping with electric clippers just before surgery
CShaving with a disposable razor the night before surgery
DShaving with a razor just before the incision
16.Infection control & patient safetyHard
A patient on a general ward for two days is found to have smear-positive pulmonary TB. What should the nurse do besides moving the patient to an airborne isolation room?
AClose the ward to all new admissions for a full year
BInform infection prevention so exposed patients and staff can be identified and followed up
CNothing more, because the patient has now been isolated
DTell all the exposed patients to start TB drugs at once, before any testing
17.Lab values & electrolytesMedium
A patient’s fasting glucose today is 98 mg/dL (5.4 mmol/L), but the HbA1c is 8.9% (74 mmol/mol). What is the best interpretation?
AGlucose control has been poor over the past 2–3 months
BThe HbA1c reflects only the past 24 hours
CThe patient does not have diabetes
DToday’s good result shows that diabetes is well controlled
18.Lab values & electrolytesHard
A young adult has fatigue, bruising and fever. The white cell count is 85 × 10³/µL with many blasts, the hemoglobin is 7.9 g/dL (79 g/L) and the platelets are 22 × 10³/µL. What is the most likely diagnosis?
AAcute leukemia
BIron-deficiency anemia
CPolycythemia vera
DAcute viral infection
3Solutions
1.Nursing fundamentals
Answer: B · Faecal impaction with overflow
Why this is the answer
Overflow happens when liquid stool seeps around impacted hard faeces. Giving antidiarrhoeal drugs would make it worse; the nurse reports it for assessment and treatment.
Answer
B · Faecal impaction with overflow
2.Nursing fundamentals
Answer: A · It widens blood vessels and can increase swelling and bleeding
Why this is the answer
Heat causes vasodilation, which can worsen swelling and bleeding in an acute injury. Cold is used first; heat may help later with stiffness.
Answer
A · It widens blood vessels and can increase swelling and bleeding
3.Clinical nursing
Answer: C · Heart rate and blood pressure
Why this is the answer
Beta-blockers lower heart rate and blood pressure, so bradycardia or hypotension may require withholding the dose and informing the prescriber.
Answer
C · Heart rate and blood pressure
4.Clinical nursing
Answer: B · 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
B · Malignant hyperthermia
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 7.50: alkalaemia (above 7.45)
PaCO₂ 24 mmHg: low (35–45)
HCO₃⁻ 18 mmol/L: low (22–26)
Compensation
partially compensated
Answer
partially compensated
6.Arterial blood gas interpretation
Answer: AGc = 17 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 = 141 − (111 + 14) = 16
Correction for albumin
16 + 0.25·(40 − 36) = 17 mmol/L
Answer
AGc = 17 mmol/L
Above about 12 after correction: a high anion gap.
7.Clinical assessment scores
Answer: B = 11
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: completely limited → 1
moisture: constantly moist → 1
activity: chairfast → 2
mobility: no limitation → 4
nutrition: very poor → 1
friction and shear: potential problem → 2
Add
Braden total = 1 + 1 + 2 + 4 + 1 + 2 = 11
Answer
B = 11
8.Clinical assessment scores
Answer: mild risk
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: very limited → 2
moisture: occasionally moist → 3
activity: walks occasionally → 3
mobility: no limitation → 4
nutrition: very poor → 1
friction and shear: potential problem → 2
Add
Braden total = 2 + 3 + 3 + 4 + 1 + 2 = 15
Risk level
15 → mild risk
Answer
mild risk
9.Enteral & parenteral nutrition calculations
Answer: IBW = 67.8 kg
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.
Height in inches
177 cm/2.54 = 69.69 in
Ideal body weight (Devine)
IBW = 45.5 + 2.3·(69.69 − 60) = 67.78 ≈ 67.8 kg
Answer
IBW = 67.8 kg
10.Enteral & parenteral nutrition calculations
Answer: E = 2111 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: 25·1800/100 = 450 g
amino acids: 4.25·1800/100 = 76.5 g
Kilocalories per component
dextrose: 450·3.4 = 1530 kcal
amino acids: 76.5·4 = 306 kcal
lipid: 250·1.1 = 275 kcal
Total energy
E = 1530 + 306 + 275 = 2111 kcal/day
Answer
E = 2111 kcal/day
11.ECG rhythm strip interpretation
Answer: QTc = 0.492 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 = 11 × 0.04 = 0.44 s
RR = 20 × 0.04 = 0.80 s
Bazett’s formula
QTc = 0.44/√0.80 = 0.44/0.8944 = 0.492 s
Answer
QTc = 0.492 s
Above the usual limits for both men (about 0.45 s) and women (about 0.46 s): prolonged. (492 ms)
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 6 small boxes apart (about 250 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: A · “Weigh him each morning before breakfast, on the same scale, and tell me the result.”
Why this is the answer
Daily weights are measured at the same time, on the same scale and in similar clothing so that changes show real fluid gain. A quick rise in weight can be an early sign of worsening heart failure.
Answer
A · “Weigh him each morning before breakfast, on the same scale, and tell me the result.”
14.Prioritization & delegation
Answer: C · New atrial fibrillation, heart rate 150/min, blood pressure 86/50 mmHg, dizzy
Why this is the answer
Rapid atrial fibrillation with hypotension and dizziness means the heart is not pumping enough blood; the patient is unstable. The other patients are within target or have predictable needs.
Answer
C · New atrial fibrillation, heart rate 150/min, blood pressure 86/50 mmHg, dizzy
15.Infection control & patient safety
Answer: B · Clipping with electric clippers just before surgery
Why this is the answer
Razors cause tiny skin cuts that bacteria can colonize, which raises the infection risk. If hair must be removed, clippers are used close to the time of surgery.
Answer
B · Clipping with electric clippers just before surgery
16.Infection control & patient safety
Answer: B · Inform infection prevention so exposed patients and staff can be identified and followed up
Why this is the answer
Infection prevention and public health carry out a contact investigation to identify and screen people exposed while the patient was not isolated. Treatment of contacts depends on their test results.
Answer
B · Inform infection prevention so exposed patients and staff can be identified and followed up
17.Lab values & electrolytes
Answer: A · Glucose control has been poor over the past 2–3 months
Why this is the answer
HbA1c shows the average glucose over about 2–3 months. One normal fasting value does not show long-term control. An HbA1c of 8.9% is well above common targets such as below 7%.Checked against:Hemoglobin A1C (HbA1c) Test · MedlinePlus (NIH) (2025)
Answer
A · Glucose control has been poor over the past 2–3 months
18.Lab values & electrolytes
Answer: A · Acute leukemia
Why this is the answer
Many circulating blasts with anemia and thrombocytopenia suggest acute leukemia: malignant cells crowd out normal production in the marrow. Despite the high white count, the patient has few working white cells and is at high risk of infection and bleeding.Checked against:Laboratory Evaluation of Acute Leukemia · StatPearls (NCBI Bookshelf) (2025)