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
Why do nurses often count the respiratory rate while still appearing to take the pulse?
AIt is not allowed to tell patients that breathing is measured
BCounting breaths is only accurate when the wrist is held
CPatients who know their breathing is watched tend to change it
DThe pulse and breathing rates are always the same number
2.Nursing fundamentalsHard
Which sequence of steps is correct when taking off personal protective equipment?
AEye protection, then mask, then gown, then gloves
BGloves, then mask, then gown, then eye protection
CGown, then mask, then gloves, then eye protection
DGloves, then eye protection, then gown, then mask
3.Clinical nursingMedium
Before giving a beta-blocker, which observation is most important to check?
AHeart rate and blood pressure
BBlood glucose only
CTemperature only
DBowel movements
4.Clinical nursingHard
A patient suddenly develops a severe "worst ever" headache that reached full intensity within seconds, followed by vomiting and neck stiffness. What should be suspected?
ASinusitis
BTension headache
CMigraine with aura in a known migraine sufferer
DSubarachnoid haemorrhage
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.38, PaCO₂ 33 mmHg (4.4 kPa) and HCO₃⁻ 19 mmol/L. The primary disorder is metabolic acidosis. How far is it compensated? Click your answer.
pH 7.38PaCO₂ 33 mmHg (4.4 kPa)HCO₃⁻ 19 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
A practice gas shows a respiratory acidosis: pH 7.24, PaCO₂ 77 mmHg (10.3 kPa), HCO₃⁻ 32 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 7.24PaCO₂ 77 mmHg (10.3 kPa)HCO₃⁻ 32 mmol/L
1acute
2chronic
3acute on chronic
7.Clinical assessment scoresMedium
Practice exercise (made-up values, not clinical guidance). A practice chart records GCS 8, with E3 and V2. What motor score M was recorded, and which response does it describe? Give the number.
GCS 8E3V2
M =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). At 5 minutes after birth, a practice newborn has a pink body with blue hands and feet, a heart rate of 60/min, a cry, cough or sneeze when stimulated, some flexion of the arms and legs and good breathing with a strong cry. Score the APGAR and click how the score is interpreted.
Practice exercise (made-up values, not clinical guidance). A 77 kg adult (BMI below 30) needs 25 kcal/kg/day. The tube feed provides 1.2 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 2400 mL of parenteral nutrition with final concentrations of 15% dextrose and 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.
2400 mLdextrose 15%amino acids 5%lipid 100 mL · 2 kcal/mL
E = kcal/day
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
1sinus bradycardia
2normal sinus rhythm
3first-degree AV block
4junctional rhythm
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
A patient had a colostomy formed yesterday. Which stoma appearance should be reported straight away?
ADark purple or black
BSlightly swollen
CA little bleeding when cleaned
DMoist and pink-red
14.Prioritization & delegationHard
A patient with diabetes is sweaty and confused, and no glucose meter is available. The patient can swallow. What should the nurse do?
AAsk the patient to lie down and sleep it off
BGive a dose of rapid-acting insulin in case the glucose is high
CWithhold all food and fluids until a meter is found
DTreat for hypoglycemia with fast-acting oral carbohydrate
15.Infection control & patient safetyMedium
A small spill of blood is found on the floor. How should it be cleaned?
AWear gloves, absorb the blood, then clean the area with an approved disinfectant
BCover it with a clean sheet and keep working
CWipe it up quickly with a dry cloth using bare hands, then wash the hands well
DLeave it until housekeeping arrives the next morning
16.Infection control & patient safetyHard
An audit shows poor hand hygiene compliance on a ward. Which plan is most likely to improve it?
ARemoving all sinks so staff must use hand rub
BA single poster about hand hygiene placed in the staff room
CA combined approach with education, hand rub at every bedside, regular audits and feedback
DDisciplining staff who are seen not cleaning their hands, with no other change
17.Lab values & electrolytesMedium
A patient taking empagliflozin (an SGLT2 inhibitor) has glucose in the urine but a normal blood glucose. What is the best interpretation?
AA urinary tract infection
BUncontrolled diabetes needing insulin
CAn expected effect of the drug
DA sign of kidney failure
18.Lab values & electrolytesHard
Which finding most strongly suggests that a patient’s raised creatinine is due to acute kidney injury rather than long-standing chronic kidney disease?
AThe patient has had a high creatinine for many years
BThe patient has long-standing anemia
CThe patient has small kidneys on an ultrasound scan
DThe creatinine was normal three days ago and has doubled since
3Solutions
1.Nursing fundamentals
Answer: C · Patients who know their breathing is watched tend to change it
Why this is the answer
Breathing can be changed on purpose, so a patient who is aware of being watched may breathe differently. Counting unobtrusively for a full minute gives a more accurate rate.
Answer
C · Patients who know their breathing is watched tend to change it
2.Nursing fundamentals
Answer: D · Gloves, then eye protection, then gown, then mask
Why this is the answer
In the CDC sequence, gloves (most contaminated) come off first, then goggles or face shield, then the gown, and finally the mask or respirator after leaving the room, with hand hygiene whenever hands become contaminated and at the end. Gown and gloves may also be removed together.
Answer
D · Gloves, then eye protection, then gown, then mask
3.Clinical nursing
Answer: A · 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
A · Heart rate and blood pressure
4.Clinical nursing
Answer: D · Subarachnoid haemorrhage
Why this is the answer
A sudden thunderclap headache suggests bleeding into the subarachnoid space, often from a ruptured aneurysm. It needs an urgent CT scan and neurosurgical input.
Answer
D · Subarachnoid haemorrhage
5.Arterial blood gas interpretation
Answer: fully 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 7.38: within 7.35–7.45
PaCO₂ 33 mmHg: low (35–45)
HCO₃⁻ 19 mmol/L: low (22–26)
Compensation
Clinically, also check the expected compensation: Winter’s formula expects PaCO₂ 34.5–38.5 mmHg, so the measured 33 mmHg points to an additional respiratory alkalosis (a mixed disorder). The answer above is the ROME exam classification.
fully compensated
Answer
fully compensated
6.Arterial blood gas interpretation
Answer: acute on chronic
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 + 1·3.7 = 27.7 mmol/L
chronic: 24 + 3.5·3.7 = 36.95 mmol/L
Compare
measured: 32 mmol/L → acute on chronic
Answer
acute on chronic
7.Clinical assessment scores
Answer: M = 3
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 − 3 − 2 = 3
M3: abnormal flexion of the arms (decorticate posture)
Answer
M = 3
8.Clinical assessment scores
Answer: reassuring
APGAR score: five signs, each scored 0, 1 or 2, checked at 1 and 5 minutes after birth. Appearance (colour): blue or pale 0, pink body with blue extremities 1, pink all over 2. Pulse: absent 0, below 100/min 1, 100/min or more 2. Grimace (reflex irritability): none 0, grimace 1, cry, cough or sneeze 2. Activity (tone): limp 0, some flexion 1, active movement 2. Respiration: absent 0, slow or irregular with a weak cry 1, good with a strong cry 2. A total of 7–10 is reassuring, 4–6 moderately abnormal and 0–3 low.
Score each sign
Appearance: a pink body with blue hands and feet → 1
Pulse: 60/min → 1
Grimace: a cry, cough or sneeze when stimulated → 2
Activity: some flexion of the arms and legs → 1
Respiration: good breathing with a strong cry → 2
Add
APGAR = 1 + 1 + 2 + 1 + 2 = 7
Interpretation
7 → reassuring
Answer
reassuring
9.Enteral & parenteral nutrition calculations
Answer: R = 67 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 = 25·77 = 1925 kcal/day
Daily volume
V = 1925/1.2 = 1604 mL/day
Pump rate
R = 1604/24 = 66.84 ≈ 67 mL/h
Answer
R = 67 mL/h
10.Enteral & parenteral nutrition calculations
Answer: E = 1904 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: 15·2400/100 = 360 g
amino acids: 5·2400/100 = 120 g
Kilocalories per component
dextrose: 360·3.4 = 1224 kcal
amino acids: 120·4 = 480 kcal
lipid: 100·2 = 200 kcal
Total energy
E = 1224 + 480 + 200 = 1904 kcal/day
Answer
E = 1904 kcal/day
11.ECG rhythm strip interpretation
Answer: sinus bradycardia
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 = 31 small boxes, 1500 ÷ 31 ≈ 48 per minute.
2. Rhythm: regular, every R–R is 1.24 s.
3. P waves: upright, one before every QRS, all alike.
4. PR interval: 0.14 s, constant, within 0.12–0.20 s.
5. QRS: 0.10 s, narrow (below 0.12 s).
Interpretation
sinus bradycardia
Answer
sinus bradycardia
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 = 50 small boxes = 2.00 s → 1500 ÷ 50 = 30 ≈ 30 per minute
Answer
atrial rate = 75 bpm
Answer
atrial rate = 75 bpm
Third-degree block with a wide-complex ventricular escape (usually 20–40 per minute).
13.Prioritization & delegation
Answer: A · Dark purple or black
Why this is the answer
A healthy stoma is moist and pink to red, and early swelling or slight bleeding is common. A dark purple or black stoma suggests poor blood supply (ischemia) and needs urgent review.
Answer
A · Dark purple or black
14.Prioritization & delegation
Answer: D · Treat for hypoglycemia with fast-acting oral carbohydrate
Why this is the answer
When in doubt, treat as hypoglycemia. A little sugar will not harm a patient with high glucose, but untreated hypoglycemia can cause brain injury within minutes, and insulin could be fatal.
Answer
D · Treat for hypoglycemia with fast-acting oral carbohydrate
15.Infection control & patient safety
Answer: A · Wear gloves, absorb the blood, then clean the area with an approved disinfectant
Why this is the answer
Blood spills are cleaned promptly by staff wearing gloves. The blood is absorbed with disposable material, then the area is cleaned and disinfected with a hospital disinfectant, and waste goes into clinical waste.
Answer
A · Wear gloves, absorb the blood, then clean the area with an approved disinfectant
16.Infection control & patient safety
Answer: C · A combined approach with education, hand rub at every bedside, regular audits and feedback
Why this is the answer
Multimodal strategies, such as easy access to hand rub at the point of care, training, reminders, audits with feedback and leadership support, improve hand hygiene more than single actions.
Answer
C · A combined approach with education, hand rub at every bedside, regular audits and feedback
17.Lab values & electrolytes
Answer: C · An expected effect of the drug
Why this is the answer
SGLT2 inhibitors block glucose reabsorption in the proximal tubule, so glycosuria is expected even with normal blood glucose. Urine glucose cannot be used to monitor control in these patients. The drugs also raise the risk of genital infections and DKA.Checked against:Ketones blood test · MedlinePlus (NIH) (2025)
Answer
C · An expected effect of the drug
18.Lab values & electrolytes
Answer: D · The creatinine was normal three days ago and has doubled since
Why this is the answer
A rapid rise from a normal baseline over days is the hallmark of acute kidney injury. Long-standing raised values, small kidneys and chronic anemia point to chronic kidney disease.Checked against:Acute Kidney Injury · StatPearls (NCBI Bookshelf) (2026)
Answer
D · The creatinine was normal three days ago and has doubled since