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 dentures be cleaned to avoid breaking them?
ABy soaking them in very hot water to sterilise them
BOver an empty, hard sink so they can be seen clearly
CWith an abrasive cleaning powder to remove stains
DOver a sink lined with a towel or partly filled with water
2.Nursing fundamentalsHard
In early hypovolaemic shock in a young adult, which sign usually appears before blood pressure falls?
AA very low blood pressure
BA rising heart rate with cool peripheries
CA slow heart rate
DWarm, flushed skin
3.Clinical nursingMedium
Why is it important to prevent hypothermia during and after surgery?
AIt causes high blood glucose only
BIt makes the patient wake up too quickly and become agitated in recovery
CIt increases the risk of wound infection, bleeding and cardiac complications
DIt makes the patient's pain disappear
4.Clinical nursingHard
A patient suddenly develops a severe "worst ever" headache that reached full intensity within seconds, followed by vomiting and neck stiffness. What should be suspected?
AMigraine with aura in a known migraine sufferer
BTension headache
CSinusitis
DSubarachnoid haemorrhage
5.Arterial blood gas interpretationMedium
A practice arterial blood gas shows pH 7.22, PaCO₂ 74 mmHg (9.9 kPa) and HCO₃⁻ 29 mmol/L. The primary disorder is respiratory acidosis. How far is it compensated? Click your answer.
pH 7.22PaCO₂ 74 mmHg (9.9 kPa)HCO₃⁻ 29 mmol/L
1uncompensated
2partially compensated
3fully compensated
6.Arterial blood gas interpretationHard
A practice gas shows pH 7.25, PaCO₂ 26 mmHg (3.5 kPa) and HCO₃⁻ 11 mmol/L, with Na⁺ 142 and Cl⁻ 102 mmol/L. Use the anion gap and the delta ratio to click the best interpretation.
Practice exercise (made-up values, not clinical guidance). Use the NEWS2 chart (SpO₂ scale 1) for these observations: respiration rate 20/min, SpO₂ 98% on supplemental oxygen, blood pressure 96/58 mmHg, pulse 88/min, alert, temperature 39.2 °C. What is the NEWS2 total score?
RR 20SpO₂ 98%O₂SBP 96HR 88AT 39.2 °C
NEWS2 =
8.Clinical assessment scoresHard
Practice exercise (made-up values, not clinical guidance). An adult weighs 91 kg and is 158 cm tall. Calculate the BMI and click the WHO weight category.
Practice exercise (made-up values, not clinical guidance). A 95 kg adult (BMI below 30) needs 35 kcal/kg/day. The tube feed provides 1.2 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 1500 mL of parenteral nutrition with final concentrations of 17.5% dextrose and 5% 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.
1500 mLdextrose 17.5%amino acids 5%lipid 500 mL · 1.1 kcal/mL
NPC : N =
11.ECG rhythm strip interpretationMedium
This lead II strip shows atrial flutter. Measure the flutter-wave interval and find the atrial rate in beats per minute.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
atrial rate = bpm
12.ECG rhythm strip interpretationHard
This lead II strip shows second-degree AV block type I (Wenckebach). Measure the PR interval of the last conducted beat before a non-conducted P wave (the longest PR), in seconds.
lead II, 25 mm/s, 10 mm/mV1 small box = 0.04 s, 1 large box = 0.20 sstrip length 6 s
longest PR = s
13.Prioritization & delegationMedium
A patient receiving an aminoglycoside antibiotic, such as gentamicin, reports ringing in the ears. What should the nurse do?
AHold the next dose and report it promptly
BReassure the patient that it is a normal effect
CGive the next dose early to finish the course
DAdvise the patient to use ear drops
14.Prioritization & delegationHard
Several patients on a unit develop diarrhea within two days. What should the nurse do first?
AWait to see if more patients become unwell
BPlace affected patients on contact precautions and inform infection control
CGive all patients antidiarrheal drugs without assessment
DMove the affected patients into shared rooms with other patients to free up beds
15.Infection control & patient safetyMedium
Which technique is used for suctioning a tracheostomy in hospital?
ASterile technique, with a sterile catheter and sterile glove
BClean technique, with the catheter rinsed in tap water
CNo gloves at all, because the airway already contains bacteria
DClean technique, reusing the catheter during the shift
16.Infection control & patient safetyHard
A nurse calls a provider using SBAR about a patient with falling blood pressure. Which statement is the “Recommendation”?
A“I am calling about Mr. Jansen in room 12, who is hypotensive.”
B“His blood pressure has fallen from 130/80 to 88/50 over the last two hours.”
C“He is 72 and had a bowel resection yesterday.”
D“I think he needs to be assessed now. Can you come within the next 15 minutes?”
17.Lab values & electrolytesMedium
In the third trimester of pregnancy, a woman's alkaline phosphatase (ALP) is about twice the usual adult range, and the other liver tests are normal. What is the best interpretation?
AA sign of blocked bile ducts
BA normal rise from placental ALP
CA sign of new bone cancer
DA sign of acute viral hepatitis
18.Lab values & electrolytesHard
A patient on an IV insulin infusion has a blood glucose of 65 mg/dL (3.6 mmol/L). What is the best action?
AGive oral potassium to protect the heart
BStop the infusion and leave the glucose recheck until the morning
CFollow the protocol for low glucose and inform the provider
DContinue at the same rate and recheck in four hours
3Solutions
1.Nursing fundamentals
Answer: D · Over a sink lined with a towel or partly filled with water
Why this is the answer
Cleaning over a padded or water-filled sink cushions a fall. Hot water can warp dentures, and abrasives scratch them; they are stored in a labelled denture pot.
Answer
D · Over a sink lined with a towel or partly filled with water
2.Nursing fundamentals
Answer: B · A rising heart rate with cool peripheries
Why this is the answer
Compensation through tachycardia and vasoconstriction keeps blood pressure normal at first, so low blood pressure is a late sign. Tachycardia, cool skin and slow capillary refill should prompt action.
Answer
B · A rising heart rate with cool peripheries
3.Clinical nursing
Answer: C · It increases the risk of wound infection, bleeding and cardiac complications
Why this is the answer
Inadvertent perioperative hypothermia impairs clotting and immune function and increases cardiac events and wound infection. Patients are warmed actively and their temperature monitored.
Answer
C · It increases the risk of wound infection, bleeding and cardiac complications
4.Clinical nursing
Answer: D · Subarachnoid haemorrhage
Why this is the answer
A sudden thunderclap headache suggests bleeding into the subarachnoid space, often from a ruptured aneurysm. It needs an urgent CT scan and neurosurgical input.
Answer
D · Subarachnoid haemorrhage
5.Arterial blood gas interpretation
Answer: partially compensated
Reading a blood gas (ROME): first the pH: below 7.35 is acidaemia, above 7.45 alkalaemia. Then find the value that explains it. PaCO₂ (normal 35–45 mmHg, 4.7–6.0 kPa) is the respiratory part and moves Opposite to the pH in a respiratory disorder; HCO₃⁻ (normal 22–26 mmol/L) is the metabolic part and moves in the same direction as the pH (Respiratory Opposite, Metabolic Equal). The other value shows the compensation: normal means uncompensated; abnormal in the direction that pulls the pH back while the pH is still abnormal means partially compensated; a normal pH with both values abnormal means fully compensated. Ranges differ slightly between laboratories; these are practice values.
ROME, value by value
pH 7.22: acidaemia (below 7.35)
PaCO₂ 74 mmHg: high (35–45)
HCO₃⁻ 29 mmol/L: high (22–26)
Compensation
partially compensated
Answer
partially compensated
6.Arterial blood gas interpretation
Answer: pure high-gap 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.
Anion gap
AG = 142 − (102 + 11) = 29
Delta ratio
(29 − 12)/(24 − 11) = 1.308
pure high-gap acidosis
Answer
pure high-gap acidosis
7.Clinical assessment scores
Answer: NEWS2 = 6
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 20/min → 0
SpO₂ 98% → 0
on oxygen → 2
SBP 96 mmHg → 2
HR 88/min → 0
alert (A) → 0
T 39.2 °C → 2
Add
NEWS2 = 0 + 0 + 2 + 2 + 0 + 0 + 2 = 6
Answer
NEWS2 = 6
8.Clinical assessment scores
Answer: obesity class II
Body mass index: BMI = weight (kg)/height (m)², with the height converted to metres first. With pounds and inches, BMI = 703 × weight (lb)/height (in)². WHO adult categories: below 18.5 underweight, 18.5–24.9 healthy weight, 25.0–29.9 overweight, 30.0–34.9 obesity class I, 35.0–39.9 obesity class II and 40 or more obesity class III.
BMI
BMI = 91/1.58² = 36.45
Category
obesity class II
Answer
obesity class II
9.Enteral & parenteral nutrition calculations
Answer: R = 173 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 = 35·95 = 3325 kcal/day
Daily volume
V = 3325/1.2 = 2771 mL/day
Pump rate
R = 2771/16 = 173.2 ≈ 173 mL/h
Answer
R = 173 mL/h
10.Enteral & parenteral nutrition calculations
Answer: NPC : N = 120
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: 17.5·1500/100 = 262.5 g
amino acids: 5·1500/100 = 75 g
Kilocalories per component
dextrose: 262.5·3.4 = 892.5 kcal
amino acids: 75·4 = 300 kcal
lipid: 500·1.1 = 550 kcal
Non-protein kcal and nitrogen
NPC = 892.5 + 550 = 1443 kcal
N = 75/6.25 = 12 g
Ratio
NPC : N = 1443/12 = 120.2 ≈ 120 : 1
Answer
NPC : N = 120
Ratios of about 150 : 1 are typical for stable patients; lower ratios give relatively more protein.
11.ECG rhythm strip interpretation
Answer: atrial rate = 300 bpm
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.
Flutter waves
F–F = 5 small boxes = 0.20 s → 1500 ÷ 5 = 300 per minute
QRS complexes
R–R = 15 small boxes = 0.60 s → 1500 ÷ 15 = 100 per minute
conduction ratio = 300 ÷ 100 = 3:1
Answer
atrial rate = 300 bpm
12.ECG rhythm strip interpretation
Answer:longest PR = 0.38 s
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.
March out the P waves
P–P = 1.00 s, regular; one P wave in every 4 is not conducted
PR in each group
PR₁ = 0.18 s, PR₂ = 0.30 s, PR₃ = 0.38 s
Answer
longest PR = 0.38 s
The biggest step in PR comes between the first and second beats of a group; later steps are smaller, which is why the R–R intervals shorten before the pause.
13.Prioritization & delegation
Answer: A · Hold the next dose and report it promptly
Why this is the answer
Aminoglycosides can cause ototoxicity, which may be permanent. Tinnitus or hearing loss is reported promptly, and drug levels and kidney function are checked.
Answer
A · Hold the next dose and report it promptly
14.Prioritization & delegation
Answer: B · Place affected patients on contact precautions and inform infection control
Why this is the answer
A cluster of diarrhea may be an outbreak, for example of C. difficile or norovirus. Contact precautions and early notification of infection control limit spread.
Answer
B · Place affected patients on contact precautions and inform infection control
15.Infection control & patient safety
Answer: A · Sterile technique, with a sterile catheter and sterile glove
Why this is the answer
In hospital, tracheal suctioning uses sterile technique to avoid introducing organisms into the lower airway. Clean technique may be taught for long-term home care, according to policy.
Answer
A · Sterile technique, with a sterile catheter and sterile glove
16.Infection control & patient safety
Answer: D · “I think he needs to be assessed now. Can you come within the next 15 minutes?”
Why this is the answer
In SBAR, the situation names the problem, the background gives the history, the assessment shares the nurse’s findings and judgement, and the recommendation states a clear request with a time frame.
Answer
D · “I think he needs to be assessed now. Can you come within the next 15 minutes?”
17.Lab values & electrolytes
Answer: B · A normal rise from placental ALP
Why this is the answer
The placenta produces ALP, so serum ALP normally rises in late pregnancy. With normal bilirubin, ALT and AST, this is expected. Symptoms such as severe itching or raised bile acids would need further review.Checked against:Alkaline Phosphatase · MedlinePlus (NIH) (2024)
Answer
B · A normal rise from placental ALP
18.Lab values & electrolytes
Answer: C · Follow the protocol for low glucose and inform the provider
Why this is the answer
A glucose below 70 mg/dL on an insulin infusion is hypoglycemia. The nurse follows the hospital’s protocol, which typically stops or reduces the insulin and gives glucose, rechecks often and informs the provider.Checked against:Low blood sugar · MedlinePlus (NIH) (2026)
Answer
C · Follow the protocol for low glucose and inform the provider