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.
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 16/min, SpO₂ 98% on supplemental oxygen, blood pressure 112/68 mmHg, pulse 76/min, alert, temperature 39.6 °C. What is the NEWS2 total score?
RR 16SpO₂ 98%O₂SBP 112HR 76AT 39.6 °C
NEWS2 =
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: yes; gait: weak; mental status: overestimates or forgets 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 56 kg adult (BMI below 30) needs 25 kcal/kg/day. The tube feed provides 1.5 kcal/mL and runs by pump for 16 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 2000 mL of parenteral nutrition with final concentrations of 20% dextrose and 4.25% amino acids, plus 500 mL of 10% lipid emulsion (1.1 kcal/mL). Find the non-protein kilocalorie to nitrogen ratio NPC : N (the number x in x : 1). Round to the nearest whole number.
2000 mLdextrose 20%amino acids 4.25%lipid 500 mL · 1.1 kcal/mL
NPC : N =
11.ECG rhythm strip interpretationMedium
Measure the QT interval and the R–R interval on this regular lead II strip, then calculate the rate-corrected QTc with Bazett’s formula QTc = QT/√RR (both in seconds). Give the answer in seconds to three decimals.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
QTc = s
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
1sinus bradycardia
2second-degree AV block type I (Wenckebach)
3second-degree AV block type II
4first-degree AV block
13.Prioritization & delegationMedium
A patient is receiving a blood transfusion. Which task can the nurse delegate to a nursing assistant?
AAssessing the patient for signs of a transfusion reaction
BStarting the transfusion once the blood arrives
CDeciding whether to stop the transfusion if the patient has chills
DMeasuring and reporting vital signs at the times set by the nurse
14.Prioritization & delegationHard
After a vaginal birth, the uterus is firm and central, but bright red blood keeps trickling steadily. What should the nurse suspect?
AUterine atony that needs more massage
BA tear in the birth canal or cervix
CNormal lochia for the first hour
DA full bladder pushing the uterus aside
15.Infection control & patient safetyMedium
A confused patient keeps pulling at an IV line. Which is a less restrictive option to consider before wrist restraints?
ATying both arms to the bed frame
BGiving a sedative every few hours
CCovering the site with a sleeve or using hand mitts with supervision
DUsing a vest restraint in the chair so that the patient’s hands stay down
16.Infection control & patient safetyHard
A nurse often skips barcode scanning to save time, as many colleagues do. In a just culture, how is this behavior classed?
AAcceptable behavior, because it is common on the unit
BSimple human error, managed only by consoling the nurse and moving on
CAt-risk behavior, managed by coaching and fixing the system pressures behind it
DReckless behavior, managed by immediate dismissal and reporting to the licensing board
17.Lab values & electrolytesMedium
A patient is starting dabigatran, a direct oral anticoagulant. Which laboratory test is most important to review before the first dose?
ALipase, to rule out an inflamed pancreas first
BKidney function (creatinine clearance)
CINR, to set the dose of the anticoagulant
DTSH, to rule out an overactive thyroid gland
18.Lab values & electrolytesHard
The nurse teaches a patient starting lithium. Which statement shows a need for further teaching?
A"I will cut out salt from my diet completely to stay healthy"
B"I will tell my doctor if I have vomiting or diarrhea"
C"I will check with the pharmacist before taking ibuprofen"
D"I will drink plenty of fluids, especially in hot weather"
3Solutions
1.Nursing fundamentals
Answer: D · The registered nurse
Why this is the answer
The nurse is accountable for delegating appropriately, to someone competent, with supervision as needed. The person who accepts the task is accountable for carrying it out properly.
Answer
D · The registered nurse
2.Nursing fundamentals
Answer: D · From the sampling port, using aseptic technique
Why this is the answer
Samples are taken from the needle-free sampling port after cleaning it. Urine in the bag is stale and contaminated, and breaking the system raises infection risk.
Answer
D · From the sampling port, using aseptic technique
3.Clinical nursing
Answer: A · Infiltration of fluid into the surrounding tissue
Why this is the answer
Infiltration causes cool, swollen, pale skin. Stop the infusion and remove the cannula. If the fluid is a vesicant, this is extravasation and needs specific management.
Answer
A · Infiltration of fluid into the surrounding tissue
4.Clinical nursing
Answer: B · A patient with asthma who can only speak in single words
Why this is the answer
Being unable to complete sentences is a sign of acute severe or life-threatening asthma, an airway and breathing emergency. The other patients need attention but are not immediately life-threatened.
Answer
B · A patient with asthma who can only speak in single words
5.Arterial blood gas interpretation
Answer: PaCO₂ = 20 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 = 1.5·8 + 8 = 20 mmHg
range: 18–22 mmHg
Answer
PaCO₂ = 20 mmHg
6.Arterial blood gas interpretation
Answer: AGc = 23.25 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 = 135 − (108 + 10) = 17
Correction for albumin
17 + 0.25·(40 − 15) = 23.25 mmol/L
Answer
AGc = 23.25 mmol/L
Above about 12 after correction: a high anion gap.
7.Clinical assessment scores
Answer: NEWS2 = 4
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 16/min → 0
SpO₂ 98% → 0
on oxygen → 2
SBP 112 mmHg → 0
HR 76/min → 0
alert (A) → 0
T 39.6 °C → 2
Add
NEWS2 = 0 + 0 + 2 + 0 + 0 + 0 + 2 = 4
Answer
NEWS2 = 4
8.Clinical assessment scores
Answer: high 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: yes → 20
gait: weak → 10
mental status: overestimates or forgets limits → 15
Add
Morse total = 0 + 0 + 15 + 20 + 10 + 15 = 60
Risk level
60 → high risk
Answer
high risk
9.Enteral & parenteral nutrition calculations
Answer: R = 58 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 = 25·56 = 1400 kcal/day
Daily volume
V = 1400/1.5 = 933.3 mL/day
Pump rate
R = 933.3/16 = 58.33 ≈ 58 mL/h
Answer
R = 58 mL/h
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 140
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: 20·2000/100 = 400 g
amino acids: 4.25·2000/100 = 85 g
Kilocalories per component
dextrose: 400·3.4 = 1360 kcal
amino acids: 85·4 = 340 kcal
lipid: 500·1.1 = 550 kcal
Non-protein kcal and nitrogen
NPC = 1360 + 550 = 1910 kcal
N = 85/6.25 = 13.6 g
Ratio
NPC : N = 1910/13.6 = 140.4 ≈ 140 : 1
Answer
NPC : N = 140
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: QTc = 0.482 s
QT and QTc: the QT interval runs from the start of the QRS complex to the end of the T wave. It shortens as the heart rate rises, so it is corrected for rate with the R–R interval in seconds: Bazett QTc = QT/√RR and Fridericia QTc = QT/∛RR. Bazett is the formula most textbooks use; it over-corrects at fast rates, where Fridericia is preferred. Limits differ between references: a QTc above about 0.45 s in men or 0.46 s in women is usually called prolonged, and above 0.50 s markedly prolonged.
Measure
QT = 10.5 × 0.04 = 0.42 s
RR = 19 × 0.04 = 0.76 s
Bazett’s formula
QTc = 0.42/√0.76 = 0.42/0.8718 = 0.482 s
Answer
QTc = 0.482 s
Above the usual limits for both men (about 0.45 s) and women (about 0.46 s): prolonged. (482 ms)
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: 4 QRS complexes in 6 s, × 10 = 40 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 0.96 s, 63 per minute); one P in every 3 is not followed by a QRS.
4. PR interval: constant at 0.16 s in the conducted beats.
5. QRS: 0.12 s, wide (0.12 s or more).
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: D · Measuring and reporting vital signs at the times set by the nurse
Why this is the answer
An assistant can measure vital signs and report them. Assessing for a reaction, starting the transfusion and deciding to stop it need the nurse’s judgement.
Answer
D · Measuring and reporting vital signs at the times set by the nurse
14.Prioritization & delegation
Answer: B · A tear in the birth canal or cervix
Why this is the answer
Continuous bright red bleeding with a firm uterus suggests a laceration of the cervix, vagina or perineum. The nurse reports it so it can be found and repaired.
Answer
B · A tear in the birth canal or cervix
15.Infection control & patient safety
Answer: C · Covering the site with a sleeve or using hand mitts with supervision
Why this is the answer
Covering the line, keeping it out of view and using mitts while observing the patient can stop pulling without fully restricting movement. Restraints and sedation are used only if these fail.
Answer
C · Covering the site with a sleeve or using hand mitts with supervision
16.Infection control & patient safety
Answer: C · At-risk behavior, managed by coaching and fixing the system pressures behind it
Why this is the answer
At-risk behavior is a choice whose risk is not recognized or is believed to be justified, often because shortcuts have become normal. It is managed by coaching and removing the pressures behind it, while reckless behavior may need disciplinary action.
Answer
C · At-risk behavior, managed by coaching and fixing the system pressures behind it
17.Lab values & electrolytes
Answer: B · Kidney function (creatinine clearance)
Why this is the answer
Dabigatran is excreted mainly by the kidneys, so poor kidney function raises the drug level and bleeding risk. Kidney function is checked before starting and regularly afterwards. Routine INR monitoring is not used for direct oral anticoagulants.
Answer
B · Kidney function (creatinine clearance)
18.Lab values & electrolytes
Answer: A · "I will cut out salt from my diet completely to stay healthy"
Why this is the answer
A sudden fall in sodium intake makes the kidneys keep more sodium and lithium, raising the lithium level towards toxicity. Patients keep a normal, steady salt intake, drink enough fluids, report fluid loss and avoid NSAIDs unless approved.
Answer
A · "I will cut out salt from my diet completely to stay healthy"