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 should an unconscious patient be positioned for mouth care?
ASitting fully upright with the head bent forwards
BProne with the face in the pillow
COn their side with the head turned, with suction ready
DFlat on their back with the head tilted back
2.Nursing fundamentalsHard
An older patient who lives alone is ready to go home after a hip fracture but worries about washing and cooking. Which referral is most appropriate?
AOccupational therapy for a home assessment
BPodiatry for nail care
CSpeech and language therapy for a swallowing assessment
DDietitian for a weight-loss plan
3.Clinical nursingMedium
Which examination findings suggest a large pleural effusion on one side?
ADull percussion and reduced breath sounds over the lung base
BNormal breath sounds and normal percussion
CWheeze heard over both lungs
DA hyper-resonant chest with the trachea pulled towards that side
4.Clinical nursingHard
Which sign is often a late finding in hypovolaemic shock in a young, previously fit adult?
ACool peripheries
BA fall in blood pressure
CA slightly raised respiratory rate
DA rise in heart rate
5.Arterial blood gas interpretationMedium
A practice gas shows a metabolic acidosis with HCO₃⁻ 12 mmol/L. Use Winter’s formula to find the expected PaCO₂ (the centre of the range) in mmHg.
HCO₃⁻ 12 mmol/L
PaCO₂ = mmHg
6.Arterial blood gas interpretationHard
A practice gas shows a metabolic acidosis: pH 7.13, PaCO₂ 44 mmHg (5.9 kPa), HCO₃⁻ 14 mmol/L. Compare the measured PaCO₂ with Winter’s formula. Click your interpretation.
pH 7.13PaCO₂ 44 mmHg (5.9 kPa)HCO₃⁻ 14 mmol/L
1appropriate compensation
2added respiratory acidosis
3added respiratory alkalosis
7.Clinical assessment scoresMedium
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: yes; ambulatory aid: crutches, cane or walker; IV therapy or saline lock: no; 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). A practice patient is assessed with the Morse fall scale: history of falling in the last 3 months: no; secondary diagnosis: no; ambulatory aid: crutches, cane or walker; IV therapy or saline lock: no; gait: normal, bed rest or wheelchair; mental status: knows own limits. Using the cut-offs 0–24 low, 25–44 moderate and 45 or more high, click the fall-risk level.
Practice exercise (made-up values, not clinical guidance). A 79 kg patient has a fluid goal of 30 mL/kg/day and receives all fluid through a feeding tube. The formula is 76% free water and runs at 90 mL/h for 24 hours a day. The rest of the fluid is given as water flushes every 8 hours. What volume V is each flush? Round to the nearest whole number.
Practice exercise (made-up values, not clinical guidance). Over 24 hours a patient receives 2000 mL of parenteral nutrition with final concentrations of 17.5% dextrose and 3.5% amino acids, plus 500 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.
2000 mLdextrose 17.5%amino acids 3.5%lipid 500 mL · 1.1 kcal/mL
E = kcal/day
11.ECG rhythm strip interpretationMedium
This lead II strip shows sinus rhythm with one pause. Measure the pause, the R–R interval across it, in seconds.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
pause = s
12.ECG rhythm strip interpretationHard
Interpret this lead II strip with the five steps in order: rate, rhythm, P waves, PR interval, QRS duration. At which step do you find the first abnormal finding? Click it.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
1rate
2rhythm
3P waves
4PR interval
5QRS duration
13.Prioritization & delegationMedium
Using the Emergency Severity Index, which patient receives the highest acuity level?
AAn unresponsive patient with gasping, irregular breaths
BA patient with chest pain and normal vital signs
CA patient with a sore throat for three days and normal vital signs
DA patient with a possible ankle fracture
14.Prioritization & delegationHard
A patient with suspected sepsis has four prescribed orders. Which should usually be done first?
ATake blood cultures
BArrange a chest X-ray for later today
CRepeat the lactate in six hours
DGive the IV antibiotic
15.Infection control & patient safetyMedium
An older adult has trouble getting in and out of the bath. Which measures make bathing safer?
AA loose rug beside the tub to stand on
BBath oil to help the person slide in and out
CA shower chair, grab bars and a non-slip mat
DLocking the bathroom door for privacy
16.Infection control & patient safetyHard
An 82-year-old patient is prescribed diphenhydramine at bedtime for sleep. Why should the nurse raise this with the prescriber?
AIt is strongly anticholinergic and can cause confusion and falls in older adults
BIt raises blood pressure in most older adults
CIt is too weak to help an older person sleep
DIt is only available as an IV drug and cannot be given by mouth at bedtime
17.Lab values & electrolytesMedium
A patient is scheduled for a liver biopsy. Which laboratory results should the nurse check before the procedure?
APlatelet count and PT/INR
BTSH and free T4
CSerum sodium and chloride
DHbA1c and lipid panel
18.Lab values & electrolytesHard
A patient has sudden episodes of severe headache, sweating, palpitations and very high blood pressure. Which test is most useful to look for the cause?
ASerum calcium only
BPlasma free metanephrines
CSerum TSH and free T4
DFasting lipid profile
3Solutions
1.Nursing fundamentals
Answer: C · On their side with the head turned, with suction ready
Why this is the answer
Side-lying lets fluid drain from the mouth instead of into the airway. Only small amounts of fluid are used, and suction is kept at hand to reduce the risk of aspiration.
Answer
C · On their side with the head turned, with suction ready
2.Nursing fundamentals
Answer: A · Occupational therapy for a home assessment
Why this is the answer
Occupational therapists assess how people manage daily activities and the home, and can arrange equipment such as perching stools and raised toilet seats.
Answer
A · Occupational therapy for a home assessment
3.Clinical nursing
Answer: A · Dull percussion and reduced breath sounds over the lung base
Why this is the answer
Fluid in the pleural space muffles breath sounds and makes percussion stony dull. A large effusion may push the trachea away from the affected side.
Answer
A · Dull percussion and reduced breath sounds over the lung base
4.Clinical nursing
Answer: B · A fall in blood pressure
Why this is the answer
Young adults compensate for blood loss with tachycardia and vasoconstriction, so blood pressure may stay normal until a large volume is lost. Hypotension is therefore a late and serious sign.
Answer
B · A fall in blood pressure
5.Arterial blood gas interpretation
Answer: PaCO₂ = 26 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 = 1.5·12 + 8 = 26 mmHg
range: 24–28 mmHg
Answer
PaCO₂ = 26 mmHg
6.Arterial blood gas interpretation
Answer: added respiratory 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.
Expected PaCO₂
1.5·14 + 8 = 29 → 27–31 mmHg
Compare
measured: 44 mmHg → added respiratory acidosis
Answer
added respiratory acidosis
7.Clinical assessment scores
Answer: MFS = 70
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: yes → 15
ambulatory aid: crutches, cane or walker → 15
IV therapy or saline lock: no → 0
gait: normal, bed rest or wheelchair → 0
mental status: overestimates or forgets limits → 15
Add
Morse total = 25 + 15 + 15 + 0 + 0 + 15 = 70
Answer
MFS = 70
8.Clinical assessment scores
Answer: low risk
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: no → 0
secondary diagnosis: no → 0
ambulatory aid: crutches, cane or walker → 15
IV therapy or saline lock: no → 0
gait: normal, bed rest or wheelchair → 0
mental status: knows own limits → 0
Add
Morse total = 0 + 0 + 15 + 0 + 0 + 0 = 15
Risk level
15 → low risk
Answer
low risk
9.Enteral & parenteral nutrition calculations
Answer: V = 243 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
30·79 = 2370 mL/day
Free water from the formula
90·24 = 2160 mL
2160·0.76 = 1642 mL
Water still needed
2370 − 1642 = 728.4 mL/day
Volume per flush
24/8 = 3 flushes
V = 728.4/3 = 242.8 ≈ 243 mL
Answer
V = 243 mL
10.Enteral & parenteral nutrition calculations
Answer: E = 2020 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: 17.5·2000/100 = 350 g
amino acids: 3.5·2000/100 = 70 g
Kilocalories per component
dextrose: 350·3.4 = 1190 kcal
amino acids: 70·4 = 280 kcal
lipid: 500·1.1 = 550 kcal
Total energy
E = 1190 + 280 + 550 = 2020 kcal/day
Answer
E = 2020 kcal/day
11.ECG rhythm strip interpretation
Answer: pause = 1.88 s
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).
Measure
47 small boxes from R to R across the pause
Convert
pause = 47 × 0.04 s = 1.88 s
Compare with P–P
1.88 ÷ 0.76 ≈ 2.5 P–P cycles, not a whole number
Answer
pause = 1.88 s
No P wave appears in the pause, and the pause is not a whole number of P–P cycles: sinus arrest. A pause of exactly two or three cycles would point to sinus exit block.
12.ECG rhythm strip interpretation
Answer: QRS duration
Five steps for every strip: 1. rate (300 or 1500 method, or the 6-second method if irregular); 2. rhythm: are the R–R intervals equal; 3. P waves: present, upright in lead II, one before every QRS and all alike; 4. PR interval: 0.12–0.20 s and constant; 5. QRS duration: below 0.12 s. Only after the five steps name the rhythm. Normal sinus rhythm passes all five: 60–100/min, regular, upright P before every QRS, PR 0.12–0.20 s, QRS below 0.12 s.
Five steps
1. Rate: R–R = 22 small boxes, 1500 ÷ 22 ≈ 68 per minute.
2. Rhythm: regular, every R–R is 0.88 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: 0.14 s, wide (0.12 s or more).
First abnormal step
QRS duration → sinus rhythm with wide QRS
Answer
QRS duration
13.Prioritization & delegation
Answer: A · An unresponsive patient with gasping, irregular breaths
Why this is the answer
An unresponsive patient with agonal breathing needs immediate airway and breathing support, which is ESI level 1. Chest pain with normal vital signs is high risk (level 2), and the others are lower levels.
Answer
A · An unresponsive patient with gasping, irregular breaths
14.Prioritization & delegation
Answer: A · Take blood cultures
Why this is the answer
Blood cultures are taken before the first antibiotic dose when this does not cause significant delay, so the organism can be identified. The antibiotic follows as soon as possible.
Answer
A · Take blood cultures
15.Infection control & patient safety
Answer: C · A shower chair, grab bars and a non-slip mat
Why this is the answer
Shower chairs, grab bars and non-slip surfaces reduce slips and falls. Bath oils make surfaces slippery, and a locked door delays help if the person falls.
Answer
C · A shower chair, grab bars and a non-slip mat
16.Infection control & patient safety
Answer: A · It is strongly anticholinergic and can cause confusion and falls in older adults
Why this is the answer
First-generation antihistamines such as diphenhydramine are on the Beers list because they cause confusion, constipation, urinary retention and falls in older adults. Safer approaches to sleep should be discussed.
Answer
A · It is strongly anticholinergic and can cause confusion and falls in older adults
17.Lab values & electrolytes
Answer: A · Platelet count and PT/INR
Why this is the answer
Liver biopsy carries a risk of bleeding, and liver disease often lowers platelets and clotting factors. Platelets and PT/INR are checked beforehand, and abnormal results are reported so they can be corrected or the procedure postponed.
Answer
A · Platelet count and PT/INR
18.Lab values & electrolytes
Answer: B · Plasma free metanephrines
Why this is the answer
These episodes suggest pheochromocytoma, a tumor of the adrenal medulla that releases catecholamines. Plasma free metanephrines (or 24-hour urine metanephrines) are the main screening tests. Hyperthyroidism can cause similar symptoms but usually without these bursts of severe hypertension.