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 is a slide sheet used to move a patient up the bed?
AIt reduces friction and shear on the skin
BIt lets one nurse lift the patient alone
CIt keeps the bed clean during the move
DIt warms the patient during the move
2.Nursing fundamentalsHard
A patient describes burning, shooting pain with pins and needles in both feet. Which type of pain is most likely?
AReferred pain
BVisceral pain
CAcute somatic pain
DNeuropathic pain
3.Clinical nursingMedium
Why is blood pressure monitored closely in a patient with an epidural infusion?
AThe epidural pump uses the blood pressure to set the rate
BEpidurals always cause severe hypertension that needs regular treatment
CThe local anaesthetic can block sympathetic nerves and cause hypotension
DBlood pressure readings show whether the catheter is infected
4.Clinical nursingHard
Soon after starting chemotherapy for a high-grade lymphoma, a patient has rising potassium, phosphate and uric acid with falling urine output. What is the most likely cause?
ARefeeding syndrome
BSyndrome of inappropriate ADH secretion
CTumour lysis syndrome
DAdrenal insufficiency
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 alkalosis with HCO₃⁻ 36 mmol/L. Use expected PaCO₂ = 0.7·HCO₃⁻ + 21 to find the expected PaCO₂.
HCO₃⁻ 36 mmol/L
PaCO₂ = mmHg
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: no; ambulatory aid: crutches, cane or walker; IV therapy or saline lock: yes; gait: impaired; mental status: knows own limits. Find the Morse total MFS.
0–125
MFS =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). The team aims for a mean arterial pressure of at least 70 mmHg. A patient’s systolic pressure is 86 mmHg. Using MAP = (SBP + 2·DBP)/3, what is the lowest diastolic pressure DBP that still gives a MAP of 70 mmHg?
Practice exercise (made-up values, not clinical guidance). A 65 kg patient needs 1.5 g of protein per kg a day. The tube feed contains 44 g of protein per litre and runs at 50 mL/h for 18 hours a day. A protein powder supplies 5 g of protein per scoop. How many scoops n a day are needed to cover the shortfall? Round up to a whole scoop.
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 4.25% amino acids, plus 250 mL of 20% lipid emulsion (2 kcal/mL). Find the non-protein kilocalorie to nitrogen ratio NPC : N (the number x in x : 1). Round to the nearest whole number.
2400 mLdextrose 15%amino acids 4.25%lipid 250 mL · 2 kcal/mL
NPC : N =
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 arrhythmia
2sinus rhythm with PVCs
3atrial fibrillation
4atrial flutter, 4:1 conduction
12.ECG rhythm strip interpretationHard
This lead II strip shows a conduction problem between the atria and the ventricles. 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
1second-degree AV block type II
2sinus bradycardia
3first-degree AV block
4third-degree (complete) AV block
13.Prioritization & delegationMedium
Two hours after birth, the nurse finds the uterus firm but above the umbilicus and pushed to the right. What should the nurse do first?
AAsk the patient to lie still for another hour
BGive a dose of oxytocin straight away
CHelp the patient empty her bladder
DMassage the uterus firmly for ten minutes
14.Prioritization & delegationHard
A nurse thinks a prescribed dose is unsafe. The prescriber says to give it anyway. What should the nurse do?
AGive the dose, because the prescriber is now responsible for it
BSkip the dose quietly and say nothing to avoid conflict
CHold the dose and escalate through the chain of command
DGive half the dose as a compromise and document the reason
15.Infection control & patient safetyMedium
Which measure is part of the bundle for inserting a central venous catheter to prevent bloodstream infection?
AChoosing the femoral vein as the first site in adults
BGiving antibiotics to every patient before insertion
CChlorhexidine-alcohol skin antisepsis and maximal sterile barrier precautions
DRoutine replacement of the catheter on a fixed schedule, such as every three days
16.Infection control & patient safetyHard
A visitor is receiving an electric shock from a faulty lamp and is still touching it. What should the nurse do first?
AThrow water over the lamp to stop the current
BSwitch off the power or unplug the lamp without touching the person
CStart chest compressions straight away
DPull the visitor away from the lamp by the arm as quickly as possible
17.Lab values & electrolytesMedium
A patient receiving chemotherapy has an ANC of 300/µL and a new temperature of 38.3 °C (100.9 °F). What should the nurse do first?
ARemove extra blankets and offer a tepid sponge bath
BEncourage oral fluids and record the fever in the chart
CReport it at once so cultures and antibiotics start quickly
DGive acetaminophen (paracetamol) and recheck the temperature in 4 hours
18.Lab values & electrolytesHard
Which set of results most strongly suggests hemolytic anemia?
ALow hemoglobin, low platelets, low white cells, low reticulocytes
BLow hemoglobin, high MCV, low vitamin B12, normal bilirubin
DLow hemoglobin, high reticulocytes, high unconjugated bilirubin, high LDH
3Solutions
1.Nursing fundamentals
Answer: A · It reduces friction and shear on the skin
Why this is the answer
Slide sheets let the patient glide rather than be dragged, protecting the skin from friction and shear and reducing strain on staff.
Answer
A · It reduces friction and shear on the skin
2.Nursing fundamentals
Answer: D · Neuropathic pain
Why this is the answer
Neuropathic pain comes from damage to nerves, for example in diabetes, and is often burning, shooting or tingling. It may respond poorly to standard analgesics and need specific drugs.
Answer
D · Neuropathic pain
3.Clinical nursing
Answer: C · The local anaesthetic can block sympathetic nerves and cause hypotension
Why this is the answer
Epidural local anaesthetic can cause vasodilation and hypotension. Nurses also monitor sedation, respiratory rate, block height, motor function and the catheter site.
Answer
C · The local anaesthetic can block sympathetic nerves and cause hypotension
4.Clinical nursing
Answer: C · Tumour lysis syndrome
Why this is the answer
Rapid tumour cell death releases potassium, phosphate and nucleic acids (forming uric acid), which can cause AKI and arrhythmias. Prevention includes IV hydration and drugs to lower uric acid.
Answer
C · Tumour lysis syndrome
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: PaCO₂ = 46.2 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.
Expected PaCO₂
0.7·36 + 21 = 46.2 mmHg
Answer
PaCO₂ = 46.2 mmHg
The rise has a limit: PaCO₂ rarely goes above about 55 mmHg from compensation alone.
7.Clinical assessment scores
Answer: MFS = 80
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: impaired → 20
mental status: knows own limits → 0
Add
Morse total = 25 + 0 + 15 + 20 + 20 + 0 = 80
Answer
MFS = 80
8.Clinical assessment scores
Answer: DBP = 62 mmHg
Blood pressure values: pulse pressure PP = SBP − DBP. Mean arterial pressure MAP ≈ (SBP + 2·DBP)/3 = DBP + PP/3, an estimate based on the heart spending about two thirds of each beat in diastole at a normal heart rate (less accurate when the heart rate is fast); a MAP of at least about 65 mmHg is a common target for organ perfusion. The shock index SI = heart rate/SBP is normally about 0.5–0.7; a value above about 1 is a warning sign of shock.
Rearrange
DBP = (3·MAP − SBP)/2
Substitute
DBP = (3·70 − 86)/2 = 124/2 = 62 mmHg
Answer
DBP = 62 mmHg
9.Enteral & parenteral nutrition calculations
Answer: n = 12
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.
Protein needed
1.5·65 = 97.5 g/day
Protein from the feed
50·18 = 900 mL = 0.9 L
0.9·44 = 39.6 g/day
Shortfall
ΔP = 97.5 − 39.6 = 57.9 g
Scoops
57.9/5 = 11.58 → n = 12
Answer
n = 12
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 106
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: 4.25·2400/100 = 102 g
Kilocalories per component
dextrose: 360·3.4 = 1224 kcal
amino acids: 102·4 = 408 kcal
lipid: 250·2 = 500 kcal
Non-protein kcal and nitrogen
NPC = 1224 + 500 = 1724 kcal
N = 102/6.25 = 16.32 g
Ratio
NPC : N = 1724/16.32 = 105.6 ≈ 106 : 1
Answer
NPC : N = 106
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: atrial fibrillation
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: 8 QRS complexes in 6 s, × 10 = 80 per minute.
2. Rhythm: irregularly irregular, R–R from 0.46 to 1.02 s with no pattern.
3. P waves: none; the baseline shows small irregular fibrillatory waves.
4. PR interval: not measurable.
5. QRS: 0.06 s, narrow (below 0.12 s).
Interpretation
atrial fibrillation
Answer
atrial fibrillation
12.ECG rhythm strip interpretation
Answer: second-degree AV block type II
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.
Five steps
1. Rate: 6 QRS complexes in 6 s, × 10 = 60 per minute.
2. Rhythm: the P waves are regular; R–R is regular except for a long pause where a QRS is missing.
3. P waves: upright and regular (P–P 0.88 s, 68 per minute); one P in every 4 is not followed by a QRS.
4. PR interval: constant at 0.16 s in the conducted beats.
5. QRS: 0.08 s, narrow (below 0.12 s).
Interpretation
second-degree AV block type II
Answer
second-degree AV block type II
Type II and third-degree blocks are the ones that can suddenly progress, so textbooks rank them as more serious than type I.
13.Prioritization & delegation
Answer: C · Help the patient empty her bladder
Why this is the answer
A uterus that is high and displaced to one side usually means a full bladder. A full bladder stops the uterus contracting well, so the nurse helps the patient void and reassesses.
Answer
C · Help the patient empty her bladder
14.Prioritization & delegation
Answer: C · Hold the dose and escalate through the chain of command
Why this is the answer
A nurse who believes an order is unsafe does not give it, documents the concern, and escalates through the chain of command until it is resolved. Changing the dose alone or silently omitting it is unsafe and outside nursing scope.
Answer
C · Hold the dose and escalate through the chain of command
15.Infection control & patient safety
Answer: C · Chlorhexidine-alcohol skin antisepsis and maximal sterile barrier precautions
Why this is the answer
The insertion bundle includes hand hygiene, chlorhexidine-alcohol skin prep, maximal barrier precautions (cap, mask, sterile gown, sterile gloves and a full body drape) and avoiding the femoral site in adults. Routine replacement and routine antibiotics are not recommended.
Answer
C · Chlorhexidine-alcohol skin antisepsis and maximal sterile barrier precautions
16.Infection control & patient safety
Answer: B · Switch off the power or unplug the lamp without touching the person
Why this is the answer
The rescuer must not touch someone still in contact with live current. The power is switched off or the plug pulled first, then the person is assessed and resuscitation is started if needed.
Answer
B · Switch off the power or unplug the lamp without touching the person
17.Lab values & electrolytes
Answer: C · Report it at once so cultures and antibiotics start quickly
Why this is the answer
Neutropenic fever is a medical emergency, because infection can progress to sepsis rapidly without the usual signs of inflammation. Blood cultures are taken and broad-spectrum antibiotics are started promptly as prescribed.Checked against:Watch Out for Fever · CDC (2024); What You Need to Know: Neutropenia and Risk for Infection · CDC
Answer
C · Report it at once so cultures and antibiotics start quickly
18.Lab values & electrolytes
Answer: D · Low hemoglobin, high reticulocytes, high unconjugated bilirubin, high LDH
Why this is the answer
When red cells break down early, hemoglobin is turned into unconjugated bilirubin and LDH is released, while the marrow increases reticulocytes. Option B fits iron deficiency, C fits B12 deficiency and D fits marrow failure.Checked against:Hemolytic anemia · MedlinePlus (NIH) (2026); Reticulocyte Count · MedlinePlus (NIH) (2024); Bilirubin Blood Test · MedlinePlus (NIH) (2024)
Answer
D · Low hemoglobin, high reticulocytes, high unconjugated bilirubin, high LDH