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
Which patient goal is written in a SMART way?
AThe patient will walk 20 metres with a frame by Friday
BThe patient will improve mobility
CThe patient will feel better soon
DThe patient will try to eat more
2.Nursing fundamentalsHard
A patient with a valid DNACPR (DNR) decision, whose death was expected, stops breathing. What should the nurse do?
ANot start CPR, note the time, inform the team and support the family
BStart CPR but stop after five minutes
CStart CPR and call the cardiac arrest team
DLeave the patient and ask the family to wait outside until the doctor comes
3.Clinical nursingMedium
A patient with dysphagia after a stroke has been cleared for a modified diet. How should they be positioned for meals?
ASitting fully upright, and staying upright for a time after eating
BLying flat on their back with the head turned to one side
CLying on their side with the knees bent
DSemi-reclined at about 20 degrees, with the head supported on pillows
4.Clinical nursingHard
A patient taking regular ibuprofen suddenly develops severe upper abdominal pain, a rigid abdomen and becomes tachycardic. What is most likely?
AConstipation
BIndigestion that will settle with antacids
CIrritable bowel syndrome
DA perforated peptic ulcer
5.Arterial blood gas interpretationMedium
A practice gas shows PaCO₂ 58 mmHg (7.7 kPa). Use the rule that in chronic respiratory acidosis HCO₃⁻ rises by 3.5 mmol/L for every 10 mmHg that PaCO₂ is above 40, starting from HCO₃⁻ 24 mmol/L, to find the expected HCO₃⁻.
Practice exercise (made-up values, not clinical guidance). A practice patient is assessed with the Morse fall scale: history of falling in the last 3 months: yes; secondary diagnosis: no; ambulatory aid: crutches, cane or walker; IV therapy or saline lock: yes; gait: normal, bed rest or wheelchair; mental status: overestimates or forgets limits. Find the Morse total MFS.
0–125
MFS =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). At 5 minutes after birth, a practice newborn has blue or pale skin all over, no heartbeat, no response to stimulation, limp limbs with no muscle tone and no breathing. Score the APGAR and click how the score is interpreted.
Practice exercise (made-up values, not clinical guidance). A 63 kg patient has a fluid goal of 30 mL/kg/day and receives all fluid through a feeding tube. The formula is 84% free water and runs at 40 mL/h for 24 hours a day. The rest of the fluid is given as water flushes every 4 hours. What volume V is each flush? Round to the nearest whole number.
Practice exercise (made-up values, not clinical guidance). A child who weighs 5.5 kg receives 5% dextrose at 25 mL/h. Find the glucose infusion rate GIR in mg/kg/min. Round to two decimal places.
5.5 kg5%25 mL/h
GIR = mg/kg/min
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 rhythm with sinus arrest
2normal sinus rhythm
3sinus bradycardia
4sinus rhythm with PVCs
12.ECG rhythm strip interpretationHard
A patient without a palpable pulse has this organised rhythm on the monitor (pulseless electrical activity). Which treatment do adult resuscitation guidelines name for 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
1immediate defibrillation
2CPR (non-shockable rhythm)
3synchronised cardioversion
4transcutaneous pacing
13.Prioritization & delegationMedium
Which medication order should the nurse question?
APotassium chloride diluted in an IV bag via a pump
BOral potassium chloride with food
CPotassium chloride oral solution diluted in juice
DPotassium chloride by IV push
14.Prioritization & delegationHard
Four patients arrive at the emergency department at the same time. Who should be seen first?
AA child with a temperature of 39 °C who is alert and drinking
BA young adult with a swollen, painful ankle after a fall on the stairs
CAn adult with kidney stone pain of 9/10 and stable vital signs
DAn older adult with weakness on one side that began 40 minutes ago
15.Infection control & patient safetyMedium
Hair must be removed from a planned surgical site. Which method reduces the risk of surgical site infection?
AShaving with a disposable razor the night before surgery
BShaving with a razor just before the incision
CClipping with electric clippers just before surgery
DUsing wax strips on the morning of surgery
16.Infection control & patient safetyHard
A patient with dementia is often found at the exit doors trying to leave the unit. Which measure is most appropriate?
AGive a sedative each time the patient goes to the door
BLock the patient alone in a single room so that they cannot reach the exit doors
CKeep the patient in a chair with a vest restraint
DUse an electronic wander alert, supervise closely and offer meaningful activity
17.Lab values & electrolytesMedium
During a red cell transfusion, when are serious acute reactions most likely, so the nurse stays with the patient?
AIn the first 15 minutes
BAfter about 2 hours
CThe next morning
DAfter the last drop is given
18.Lab values & electrolytesHard
A young woman with frequent self-induced vomiting has swollen salivary glands. Which laboratory pattern is most likely?
AHigh potassium, low bicarbonate and low amylase
BHigh calcium, high phosphate and high glucose
CLow sodium, low bicarbonate and high lipase
DLow potassium, high bicarbonate and high amylase
3Solutions
1.Nursing fundamentals
Answer: A · The patient will walk 20 metres with a frame by Friday
Why this is the answer
A SMART goal states exactly what is expected, how it will be measured and by when. "Walk 20 metres with a frame by Friday" can be checked; "feel better" cannot.
Answer
A · The patient will walk 20 metres with a frame by Friday
2.Nursing fundamentals
Answer: A · Not start CPR, note the time, inform the team and support the family
Why this is the answer
CPR is not attempted when a valid DNACPR decision applies. The nurse notes the time, follows local policy for verifying death, informs the medical team and supports the family.
Answer
A · Not start CPR, note the time, inform the team and support the family
3.Clinical nursing
Answer: A · Sitting fully upright, and staying upright for a time after eating
Why this is the answer
Sitting upright during and after meals reduces the risk of aspiration. The patient should also be supervised and given the consistency recommended by the speech and language therapist.
Answer
A · Sitting fully upright, and staying upright for a time after eating
4.Clinical nursing
Answer: D · A perforated peptic ulcer
Why this is the answer
Sudden severe pain with a board-like abdomen suggests perforation and peritonitis. The patient needs nil by mouth, IV access, analgesia and urgent surgical review.
Answer
D · A perforated peptic ulcer
5.Arterial blood gas interpretation
Answer: HCO₃⁻ = 30.3 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.
Change in PaCO₂
|58 − 40| = 18 mmHg → 1.8 × 10 mmHg
Expected HCO₃⁻
HCO₃⁻ = 24 + 3.5·1.8 = 30.3 mmol/L
Answer
HCO₃⁻ = 30.3 mmol/L
6.Arterial blood gas interpretation
Answer: AGc = 21.5 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 = 140 − (105 + 17) = 18
Correction for albumin
18 + 0.25·(40 − 26) = 21.5 mmol/L
Answer
AGc = 21.5 mmol/L
Above about 12 after correction: a high anion gap.
7.Clinical assessment scores
Answer: MFS = 75
Morse fall scale: six items. History of falling: no 0, yes 25. Secondary diagnosis: no 0, yes 15. Ambulatory aid: none, bed rest or nurse assistance 0; crutches, cane or walker 15; holding on to furniture 30. IV therapy or saline lock: no 0, yes 20. Gait: normal, bed rest or wheelchair 0; weak 10; impaired 20. Mental status: knows own limits 0; overestimates or forgets limits 15. The total runs from 0 to 125. Risk cut-offs differ between hospitals; a common set is 0–24 low, 25–44 moderate and 45 or more high.
Score each item
history of falling in the last 3 months: yes → 25
secondary diagnosis: no → 0
ambulatory aid: crutches, cane or walker → 15
IV therapy or saline lock: yes → 20
gait: normal, bed rest or wheelchair → 0
mental status: overestimates or forgets limits → 15
Add
Morse total = 25 + 0 + 15 + 20 + 0 + 15 = 75
Answer
MFS = 75
8.Clinical assessment scores
Answer: low
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: blue or pale skin all over → 0
Pulse: 0 → 0
Grimace: no response to stimulation → 0
Activity: limp limbs with no muscle tone → 0
Respiration: no breathing → 0
Add
APGAR = 0 + 0 + 0 + 0 + 0 = 0
Interpretation
0 → low
Answer
low
Below 7 at 5 minutes, the score is usually repeated every 5 minutes up to 20 minutes.
9.Enteral & parenteral nutrition calculations
Answer: V = 181 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
30·63 = 1890 mL/day
Free water from the formula
40·24 = 960 mL
960·0.84 = 806.4 mL
Water still needed
1890 − 806.4 = 1084 mL/day
Volume per flush
24/4 = 6 flushes
V = 1084/6 = 180.6 ≈ 181 mL
Answer
V = 181 mL
10.Enteral & parenteral nutrition calculations
Answer: GIR = 3.79 mg/kg/min
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.
Dextrose concentration
5% = 50 mg/mL
Dextrose per minute
50·25/60 = 20.83 mg/min
Per kilogram
GIR = 20.83/5.5 = 3.788 ≈ 3.79 mg/kg/min
Answer
GIR = 3.79 mg/kg/min
Shortcut: GIR = % dextrose × mL/h/(6 × kg).
11.ECG rhythm strip interpretation
Answer: sinus rhythm with sinus arrest
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. Narrow-complex tachycardia and pauses: supraventricular tachycardia (SVT) is a regular tachycardia at about 150–250/min with narrow QRS complexes; the P waves are usually not visible because they are hidden in the QRS complex or the T wave. Sinus tachycardia in an adult at rest is usually below about 150/min and has a visible P wave before every QRS; atrial flutter with 2:1 conduction often runs at about 150/min and shows sawtooth waves. In sinus arrest the sinus node stops firing for a moment: a pause with no P wave and no QRS whose length is not a whole number of P–P cycles (a pause of exactly two or three cycles points to sinus exit block instead).
Five steps
1. Rate: 5 QRS complexes in 6 s, × 10 = 50 per minute.
2. Rhythm: regular (R–R 0.96 s) except for one pause of 2.24 s, which is not a whole number of P–P cycles.
3. P waves: upright, one before every QRS; no P wave at all during the pause.
4. PR interval: 0.14 s, constant, within 0.12–0.20 s.
5. QRS: 0.08 s, narrow (below 0.12 s).
Interpretation
sinus rhythm with sinus arrest
Answer
sinus rhythm with sinus arrest
12.ECG rhythm strip interpretation
Answer: CPR (non-shockable rhythm)
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 = 28 small boxes, 1500 ÷ 28 ≈ 54 per minute.
2. Rhythm: regular, every R–R is 1.12 s.
3. P waves: upright, one before every QRS, all alike.
4. PR interval: 0.18 s, constant, within 0.12–0.20 s.
5. QRS: 0.08 s, narrow (below 0.12 s).
sinus bradycardia
What the patient shows
no pulse despite organised electrical activity: pulseless electrical activity (PEA), a non-shockable cardiac arrest rhythm
Answer
CPR (non-shockable rhythm)
Answer
CPR (non-shockable rhythm)
PEA is recognised at the bedside, never from the strip alone. This is exam practice, not clinical guidance.
13.Prioritization & delegation
Answer: D · Potassium chloride by IV push
Why this is the answer
Potassium chloride must never be given by IV push, because a rapid dose can cause cardiac arrest. It is diluted and given slowly through an infusion pump.
Answer
D · Potassium chloride by IV push
14.Prioritization & delegation
Answer: D · An older adult with weakness on one side that began 40 minutes ago
Why this is the answer
Sudden one-sided weakness suggests a stroke, and treatment depends on how quickly it starts. Severe kidney stone pain needs prompt pain relief, but the patient is stable.
Answer
D · An older adult with weakness on one side that began 40 minutes ago
15.Infection control & patient safety
Answer: C · 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
C · Clipping with electric clippers just before surgery
16.Infection control & patient safety
Answer: D · Use an electronic wander alert, supervise closely and offer meaningful activity
Why this is the answer
Wander alert systems, close supervision, orientation and activity reduce the risk of elopement without restricting the patient. Seclusion, restraints and sedation used for convenience are not appropriate.
Answer
D · Use an electronic wander alert, supervise closely and offer meaningful activity
17.Lab values & electrolytes
Answer: A · In the first 15 minutes
Why this is the answer
Acute hemolytic and anaphylactic reactions usually appear early, so the transfusion is started slowly and the nurse stays with the patient for about the first 15 minutes, checking vital signs before, during and after according to policy.
Answer
A · In the first 15 minutes
18.Lab values & electrolytes
Answer: D · Low potassium, high bicarbonate and high amylase
Why this is the answer
Repeated vomiting causes hypokalemia and metabolic alkalosis (high bicarbonate) from the loss of stomach acid. Enlarged salivary glands can raise salivary amylase. Hypokalemia can cause dangerous arrhythmias, so it is monitored and corrected.Checked against:Bulimia · MedlinePlus (NIH) (2026)
Answer
D · Low potassium, high bicarbonate and high amylase