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
How can a patient reduce pain when coughing after abdominal surgery?
ALie flat on their back with arms by their sides
BCough while bending forward with no support
CHold a pillow firmly against the wound while coughing
DAvoid coughing completely until the stitches have been removed
2.Nursing fundamentalsHard
Which of these patients should the nurse attend to first?
AA patient asking for their regular evening medicines
BA patient with diabetes who is sweaty and shaky with a glucose of 2.9 mmol/L (52 mg/dL)
CA patient with a pain score of 4/10 who had analgesia 30 minutes ago
DA patient who wants to talk about the results of a scan
3.Clinical nursingMedium
Which side effect is associated with SGLT2 inhibitors such as dapagliflozin?
ABradycardia
BGenital fungal infections
CSevere weight gain and fluid retention
DHair loss
4.Clinical nursingHard
Why must a unit of red cells be transfused within the set time limit (commonly four hours) after it leaves controlled cold storage?
AThe blood group of the cells changes after a few hours
BThe bag stops dripping after four hours
CBacteria can grow in the blood at room temperature
DThe red cells break down and turn into plasma
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.44, PaCO₂ 29 mmHg (3.9 kPa) and HCO₃⁻ 19 mmol/L. The primary disorder is respiratory alkalosis. How far is it compensated? Click your answer.
pH 7.44PaCO₂ 29 mmHg (3.9 kPa)HCO₃⁻ 19 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
At sea level, a practice gas taken on 40% oxygen shows PaO₂ 73 mmHg (9.7 kPa) and PaCO₂ 34 mmHg (4.5 kPa). Use PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 to find the A–a gradient.
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 14/min, SpO₂ 95% on supplemental oxygen, blood pressure 150/90 mmHg, pulse 88/min, alert, temperature 37.0 °C. What is the NEWS2 total score?
RR 14SpO₂ 95%O₂SBP 150HR 88AT 37.0 °C
NEWS2 =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). At 1 minute after birth, a practice newborn has a pink body with blue hands and feet, a heart rate of 95/min, a grimace when stimulated, some flexion of the arms and legs and no breathing. Score the APGAR and click how the score is interpreted.
Practice exercise (made-up values, not clinical guidance). Use the Devine formula to find the ideal body weight IBW of a man who is 181 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 2400 mL of parenteral nutrition with final concentrations of 10% dextrose and 5% amino acids, plus 500 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 10%amino acids 5%lipid 500 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
1junctional rhythm
2first-degree AV block
3atrial fibrillation
4normal sinus rhythm
12.ECG rhythm strip interpretationHard
A monitored patient is found unresponsive and not breathing normally, and no carotid pulse can be felt. The monitor shows this organised rhythm. What is this situation called? 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
1normal sinus rhythm
2asystole
3pulseless electrical activity (PEA)
4ventricular fibrillation
13.Prioritization & delegationMedium
Which action helps prevent a catheter-associated urinary tract infection?
ADisconnecting the bag every shift to empty it
BKeeping the drainage bag below the level of the bladder
CLeaving the catheter in place longer than needed
DRaising the drainage bag above the bladder when walking
14.Prioritization & delegationHard
A patient is receiving IV potassium chloride through a peripheral line and complains of burning at the site, which looks red. What does the nurse do first?
AIncrease the infusion rate to finish the dose sooner
BApply a warm pack and continue the infusion
CStop the infusion and assess the IV site
DTell the patient that burning is expected and continue
15.Infection control & patient safetyMedium
An alcohol-based skin prep has been used before surgery with electrosurgery. What must happen before the drapes are placed?
AThe prep must be fully dry and any pooled liquid removed
BThe prep must be wiped off with saline
CThe prep must be warmed with a hair dryer
DThe prep must be covered with the drapes while it is still wet
16.Infection control & patient safetyHard
A patient’s blood splashes onto a nurse’s forearm. The skin is intact. What is the correct response?
ADo nothing, because intact skin cannot be contaminated
BWash the area with soap and water, then follow the reporting policy
CStart HIV post-exposure prophylaxis right away, before any other step is taken
DScrub the area with undiluted bleach
17.Lab values & electrolytesMedium
A patient who has been vomiting for two days has a BUN of 32 mg/dL (urea 11.4 mmol/L) and a normal creatinine. What is the most likely cause?
ALow-protein diet
BLiver failure
CDehydration
DOverhydration
18.Lab values & electrolytesHard
A patient with long-term heavy alcohol use is admitted with alcohol withdrawal. Which group of electrolyte problems is most common?
ALow chloride, high bicarbonate and high calcium
BHigh sodium, high calcium and high glucose
CHigh magnesium, high phosphate and high potassium
DLow magnesium, low phosphate and low potassium
3Solutions
1.Nursing fundamentals
Answer: C · Hold a pillow firmly against the wound while coughing
Why this is the answer
Splinting the incision with a pillow or folded towel supports the wound and reduces pain, so the patient can cough effectively and clear secretions.
Answer
C · Hold a pillow firmly against the wound while coughing
2.Nursing fundamentals
Answer: B · A patient with diabetes who is sweaty and shaky with a glucose of 2.9 mmol/L (52 mg/dL)
Why this is the answer
Hypoglycaemia can quickly lead to unconsciousness and seizures and needs immediate treatment. The other patients' needs are important but can wait a few minutes.
Answer
B · A patient with diabetes who is sweaty and shaky with a glucose of 2.9 mmol/L (52 mg/dL)
3.Clinical nursing
Answer: B · Genital fungal infections
Why this is the answer
SGLT2 inhibitors cause glycosuria, which increases the risk of genital thrush and urinary infections. They can also rarely cause DKA with only modestly raised glucose.
Answer
B · Genital fungal infections
4.Clinical nursing
Answer: C · Bacteria can grow in the blood at room temperature
Why this is the answer
Red cells are stored cold to limit bacterial growth. Once out of controlled storage, the transfusion must be completed within the time limit to reduce the risk of bacterial contamination and transfusion-transmitted infection.
Answer
C · Bacteria can grow in the blood at room temperature
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 7.44: within 7.35–7.45
PaCO₂ 29 mmHg: low (35–45)
HCO₃⁻ 19 mmol/L: low (22–26)
Compensation
fully compensated
Answer
fully compensated
6.Arterial blood gas interpretation
Answer: A–a gradient = 169.7 mmHg
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.
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 95% → 1
on oxygen → 2
SBP 150 mmHg → 0
HR 88/min → 0
alert (A) → 0
T 37.0 °C → 0
Add
NEWS2 = 0 + 1 + 2 + 0 + 0 + 0 + 0 = 3
Answer
NEWS2 = 3
8.Clinical assessment scores
Answer: moderately abnormal
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: 95/min → 1
Grimace: a grimace when stimulated → 1
Activity: some flexion of the arms and legs → 1
Respiration: no breathing → 0
Add
APGAR = 1 + 1 + 1 + 1 + 0 = 4
Interpretation
4 → moderately abnormal
Answer
moderately abnormal
9.Enteral & parenteral nutrition calculations
Answer: IBW = 75.9 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
181 cm/2.54 = 71.26 in
Ideal body weight (Devine)
IBW = 50 + 2.3·(71.26 − 60) = 75.9 kg
Answer
IBW = 75.9 kg
10.Enteral & parenteral nutrition calculations
Answer: E = 2296 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: 10·2400/100 = 240 g
amino acids: 5·2400/100 = 120 g
Kilocalories per component
dextrose: 240·3.4 = 816 kcal
amino acids: 120·4 = 480 kcal
lipid: 500·2 = 1000 kcal
Total energy
E = 816 + 480 + 1000 = 2296 kcal/day
Answer
E = 2296 kcal/day
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 = 35 small boxes, 1500 ÷ 35 ≈ 43 per minute.
2. Rhythm: regular, every R–R is 1.40 s.
3. P waves: inverted, just before each QRS.
4. PR interval: 0.08 s, shorter than 0.12 s.
5. QRS: 0.06 s, narrow (below 0.12 s).
Interpretation
junctional rhythm
Answer
junctional rhythm
12.ECG rhythm strip interpretation
Answer: pulseless electrical activity (PEA)
Pulseless electrical activity (PEA): PEA cannot be seen on a strip. The monitor shows organised electrical activity (a rhythm other than VF, VT or asystole) but the patient has no palpable pulse, so it is recognised by checking the patient. In adult resuscitation guidelines PEA and asystole are the non-shockable cardiac arrest rhythms: high-quality CPR, epinephrine as soon as possible and a search for reversible causes (the Hs and Ts, such as hypovolaemia, hypoxia, tension pneumothorax and cardiac tamponade). VF and pulseless VT are the shockable rhythms.
What the strip shows
1. Rate: R–R = 18 small boxes, 1500 ÷ 18 ≈ 83 per minute.
2. Rhythm: regular, every R–R is 0.72 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: 0.08 s, narrow (below 0.12 s).
normal sinus rhythm
What the patient shows
no pulse despite organised electrical activity: pulseless electrical activity (PEA), a non-shockable cardiac arrest rhythm
Answer
pulseless electrical activity (PEA)
Answer
pulseless electrical activity (PEA)
PEA is recognised at the bedside, never from the strip alone. This is exam practice, not clinical guidance.
13.Prioritization & delegation
Answer: B · Keeping the drainage bag below the level of the bladder
Why this is the answer
Keeping the bag below the bladder prevents backflow, and the closed system is not broken. Catheters are removed as soon as they are no longer needed.
Answer
B · Keeping the drainage bag below the level of the bladder
14.Prioritization & delegation
Answer: C · Stop the infusion and assess the IV site
Why this is the answer
Pain and redness suggest phlebitis or infiltration. The nurse stops the infusion, assesses the site and informs the provider. Continuing the infusion, or giving it faster, increases tissue damage.
Answer
C · Stop the infusion and assess the IV site
15.Infection control & patient safety
Answer: A · The prep must be fully dry and any pooled liquid removed
Why this is the answer
Wet alcohol prep and its vapors under drapes can be ignited by electrosurgery or lasers. The prep is allowed to dry fully, and pooling in skin folds or linen is prevented.
Answer
A · The prep must be fully dry and any pooled liquid removed
16.Infection control & patient safety
Answer: B · Wash the area with soap and water, then follow the reporting policy
Why this is the answer
Blood on intact skin carries very little risk of bloodborne infection, but it is still washed off promptly and handled according to policy. Bleach damages skin, and prophylaxis is for higher-risk exposures.
Answer
B · Wash the area with soap and water, then follow the reporting policy
17.Lab values & electrolytes
Answer: C · Dehydration
Why this is the answer
When the body is short of fluid, the kidneys reabsorb more urea, so the BUN rises out of proportion to creatinine (a BUN-to-creatinine ratio above 20:1). Liver failure and a low-protein diet lower the BUN.Checked against:BUN (Blood Urea Nitrogen) · MedlinePlus (NIH) (2024)
Answer
C · Dehydration
18.Lab values & electrolytes
Answer: D · Low magnesium, low phosphate and low potassium
Why this is the answer
Poor diet, vomiting, diarrhea and alcohol's effect on the kidneys commonly cause low magnesium, phosphate and potassium. These worsen arrhythmia and seizure risk, so they are checked and replaced, together with thiamine.
Answer
D · Low magnesium, low phosphate and low potassium