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 of these is recorded as fluid intake on a fluid balance chart?
AVomit
BUrine output from a catheter
CWound drainage
DIntravenous fluids
2.Nursing fundamentalsHard
A patient needs a painful dressing change. When is it best to give the prescribed oral analgesic?
AImmediately after the dressing change
BThe same time the next day
CEarly enough before the procedure for it to reach its peak effect
DOnly if the patient shows signs of pain or cries out during the procedure
3.Clinical nursingMedium
During a red cell transfusion, when are serious acute reactions most likely to start?
AAbout 24 hours later
BIn the first 15 minutes
COnly after the unit has finished
DAfter the third unit only
4.Clinical nursingHard
A patient with a head injury has a GCS that falls from 14 to 10 and one pupil becomes larger and slow to react. What should the nurse do?
AEncourage the patient to sleep
BRecheck the GCS at the next routine observation round
CEscalate immediately as a neurological emergency
DGive a sedative to calm the patient
5.Arterial blood gas interpretationMedium
Practice values: Na⁺ 150 mmol/L, glucose 4.3 mmol/L and urea 9.6 mmol/L. Calculate the serum osmolality Osm = 2·Na⁺ + glucose + urea to the nearest whole number.
Na⁺ 150 mmol/Lglucose 4.3 mmol/Lurea 9.6 mmol/L
Osm = mOsm/kg
6.Arterial blood gas interpretationHard
A practice gas shows a metabolic acidosis: pH 7.17, PaCO₂ 17 mmHg (2.3 kPa), HCO₃⁻ 6 mmol/L. Compare the measured PaCO₂ with Winter’s formula. Click your interpretation.
pH 7.17PaCO₂ 17 mmHg (2.3 kPa)HCO₃⁻ 6 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 Braden scale: sensory perception: slightly limited; moisture: occasionally moist; activity: walks frequently; mobility: very limited; nutrition: probably inadequate; friction and shear: problem. Find the Braden total B.
6–23
B =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 18/min, SpO₂ 96% on room air, blood pressure 110/66 mmHg, pulse 132/min, responds only to pain, temperature 35.8 °C. Which clinical risk group does the patient fall into? Click it.
Practice exercise (made-up values, not clinical guidance). A man is 189 cm tall and weighs 89 kg. Find the actual weight as a percentage of the ideal body weight, %IBW, using the Devine formula (1 in = 2.54 cm). Round to the nearest whole number.
Practice exercise (made-up values, not clinical guidance). A child who weighs 8.5 kg receives 5% dextrose at 32 mL/h. Find the glucose infusion rate GIR in mg/kg/min. Round to two decimal places.
8.5 kg5%32 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
1first-degree AV block
2sinus tachycardia
3normal sinus rhythm
4junctional rhythm
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
Which SBAR recommendation is the clearest?
A“I just wanted to let you know about him.”
B“He seems a bit off tonight, so maybe you could come up and do something about it.”
C“I will keep watching him and call again tomorrow.”
D“I would like you to see him within 15 minutes and consider a fluid bolus.”
14.Prioritization & delegationHard
A medical-unit nurse is floated to intensive care and given a patient on a ventilator, which the nurse has never managed. What is the best response?
ARefuse to work and go home, because the assignment is unsafe
BTell the charge nurse about the gap, accept tasks within competence and ask for support
CLeave the intensive care unit and go back to the medical unit without telling anyone
DAccept the full assignment without comment to avoid conflict
15.Infection control & patient safetyMedium
Which patient has the highest risk of a burn from a heating pad?
AA patient with a sprained wrist who is fully alert
BA healthy young adult with a strained muscle
CA patient recovering from a cold
DA patient with diabetic peripheral neuropathy
16.Infection control & patient safetyHard
During a power cut in a US hospital, a ventilator must stay powered. Where should it be plugged in?
AInto any white outlet in the room
BInto the outlet that is closest to the bed, whatever its color
CInto an extension cord from the corridor
DInto a red outlet connected to the emergency generator
17.Lab values & electrolytesMedium
Which instruction is correct for a patient starting oral iron tablets?
ATake each tablet with milk to protect the stomach
BYour urine will turn bright orange while you take it
CYour stools may turn dark green or black
DTake the tablet with an antacid to improve absorption
18.Lab values & electrolytesHard
The nurse teaches a patient who is starting warfarin. Which statement shows a need for further teaching?
A"I will keep my intake of green leafy vegetables about the same"
B"I will tell my dentist and pharmacist that I take warfarin"
C"I will have my INR checked as often as I am told to"
D"If I miss a dose, I will take two tablets the next day"
3Solutions
1.Nursing fundamentals
Answer: D · Intravenous fluids
Why this is the answer
Intake includes oral fluids, enteral feeds and IV fluids, including drug infusions. Urine, vomit, drainage and stool are output.
Answer
D · Intravenous fluids
2.Nursing fundamentals
Answer: C · Early enough before the procedure for it to reach its peak effect
Why this is the answer
Giving analgesia in advance, timed to the drug's onset and peak, means the pain relief is working during the procedure. This is more effective than treating pain after it has started.
Answer
C · Early enough before the procedure for it to reach its peak effect
3.Clinical nursing
Answer: B · In the first 15 minutes
Why this is the answer
Severe reactions such as ABO incompatibility and anaphylaxis usually begin early. The patient should be watched closely in the first 15 minutes, with observations repeated as per local policy.
Answer
B · In the first 15 minutes
4.Clinical nursing
Answer: C · Escalate immediately as a neurological emergency
Why this is the answer
A falling GCS with a unilateral dilated pupil suggests rising intracranial pressure and possible brain herniation. Urgent medical review and imaging are needed.
Answer
C · Escalate immediately as a neurological emergency
5.Arterial blood gas interpretation
Answer: Osm = 314 mOsm/kg
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.
Calculated osmolality
Osm = 2·150 + 4.3 + 9.6 = 313.9 ≈ 314 mOsm/kg
Answer
Osm = 314 mOsm/kg
6.Arterial blood gas interpretation
Answer: appropriate compensation
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
1.5·6 + 8 = 17 → 15–19 mmHg
Compare
measured: 17 mmHg → appropriate compensation
Answer
appropriate compensation
7.Clinical assessment scores
Answer: B = 15
Braden scale: six subscales for pressure-injury risk. Sensory perception, moisture, activity, mobility and nutrition score 1 to 4, from the worst level (1) to no problem (4); friction and shear scores 1 to 3. The total runs from 6 to 23, and a lower total means a higher risk. Common bands: 19–23 not at risk, 15–18 mild risk, 13–14 moderate risk, 10–12 high risk and 9 or below very high risk.
Score each subscale
sensory perception: slightly limited → 3
moisture: occasionally moist → 3
activity: walks frequently → 4
mobility: very limited → 2
nutrition: probably inadequate → 2
friction and shear: problem → 1
Add
Braden total = 3 + 3 + 4 + 2 + 2 + 1 = 15
Answer
B = 15
8.Clinical assessment scores
Answer: high
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 18/min → 0
SpO₂ 96% → 0
on air → 0
SBP 110 mmHg → 1
HR 132/min → 3
responds only to pain (P) → 3
T 35.8 °C → 1
Total and red scores
NEWS2 = 0 + 0 + 0 + 1 + 3 + 3 + 1 = 8
At least one parameter scores 3.
Risk group
high
Answer
high
A total of 5 or more calls for an urgent clinical response.
9.Enteral & parenteral nutrition calculations
Answer: %IBW = 107 %
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.
Ideal body weight (Devine)
189 cm/2.54 = 74.41 in
IBW = 50 + 2.3·(74.41 − 60) = 83.14 kg
Percentage of ideal body weight
%IBW = 89/83.14·100 = 107%
Answer
%IBW = 107%
10.Enteral & parenteral nutrition calculations
Answer: GIR = 3.14 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
50·32/60 = 26.67 mg/min
Per kilogram
GIR = 26.67/8.5 = 3.137 ≈ 3.14 mg/kg/min
Answer
GIR = 3.14 mg/kg/min
Shortcut: GIR = % dextrose × mL/h/(6 × kg).
11.ECG rhythm strip interpretation
Answer: normal sinus 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 = 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: 0.06 s, narrow (below 0.12 s).
Interpretation
normal sinus rhythm
Answer
normal sinus rhythm
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 = 16 small boxes, 1500 ÷ 16 ≈ 94 per minute.
2. Rhythm: regular, every R–R is 0.64 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: 0.12 s, wide (0.12 s or more).
First abnormal step
QRS duration → sinus rhythm with wide QRS
Answer
QRS duration
13.Prioritization & delegation
Answer: D · “I would like you to see him within 15 minutes and consider a fluid bolus.”
Why this is the answer
A good recommendation is specific about the request and the time frame. Vague statements leave the provider unsure how urgent the problem is.
Answer
D · “I would like you to see him within 15 minutes and consider a fluid bolus.”
14.Prioritization & delegation
Answer: B · Tell the charge nurse about the gap, accept tasks within competence and ask for support
Why this is the answer
A nurse should clearly state the limits of their competence and ask for an assignment or support that keeps patients safe. Leaving without handover would be patient abandonment.
Answer
B · Tell the charge nurse about the gap, accept tasks within competence and ask for support
15.Infection control & patient safety
Answer: D · A patient with diabetic peripheral neuropathy
Why this is the answer
Reduced sensation, as in peripheral neuropathy, prevents a person from feeling heat damage. Patients with poor sensation, poor circulation or confusion need very close monitoring if heat is used at all.
Answer
D · A patient with diabetic peripheral neuropathy
16.Infection control & patient safety
Answer: D · Into a red outlet connected to the emergency generator
Why this is the answer
In US hospitals, red outlets are usually connected to the emergency generator. Life-support equipment is plugged into them, and battery backups are checked as part of emergency planning.
Answer
D · Into a red outlet connected to the emergency generator
17.Lab values & electrolytes
Answer: C · Your stools may turn dark green or black
Why this is the answer
Oral iron commonly darkens the stools, which is harmless, but black tarry stools with abdominal pain should be reported. Milk, antacids and tea reduce absorption; vitamin C or orange juice can improve it.
Answer
C · Your stools may turn dark green or black
18.Lab values & electrolytes
Answer: D · "If I miss a dose, I will take two tablets the next day"
Why this is the answer
Doubling a missed warfarin dose can raise the INR and cause bleeding; the patient should follow the prescriber's instructions, usually taking the missed dose the same day or skipping it. A steady vitamin K intake, regular INR checks and telling other providers are correct.
Answer
D · "If I miss a dose, I will take two tablets the next day"