Station 16 of 33 · Free

A positive fluid balance and a falling urine output after bowel surgery.

Fluid balance
Skills stations
Surgical ward, 06:00
Simulated patient (actor)
14 minutes

Station timer: 14 minutes [S4] for this skill in adult nursing, with a prompt 3 minutes before the end [S5].

Station brief

Setting: Surgical ward, 06:00. Patient: Simulated patient (actor).

You are the registered nurse on the surgical ward at 06:00. Mr Samuel Adeyemi, 68, is day 1 after a laparotomy for a bowel obstruction.

He has a urinary catheter with an hourly measuring bag, a nasogastric tube on free drainage, a wound drain and IV fluids. He is allowed sips of water only.

The fluid balance chart started at 08:00 yesterday. The night nurse asks you to total it so far, work out the running balance and act on what you find. You may not use a calculator.

In 14 minutes:

Check his identity and explain what you are doing.
Total the intake and the output on the fluid balance chart, and work out the running balance.
Assess Mr Adeyemi in the light of your findings and say what you will do next.
Document your totals and actions.

In the station: Fluid balance chart (08:00 yesterday to 06:00 today), NEWS2 observation chart, prescription chart with IV fluids, black pen, alcohol-based hand rub.

Findings: what the patient or assessor tells you

Open these as you assess, one at a time, the way an assessor or patient would give them.

Intake on the chart: IV Hartmann's solution 1000 mL, 08:00 to 18:00. IV sodium chloride 0.9% 1000 mL, 18:00 to 06:00. Oral sips 300 mL in total. Nothing else.
Output on the chart: urine 08:00 to 01:00, 560 mL in total. Then hourly urine: 02:00 20 mL, 03:00 15 mL, 04:00 15 mL, 05:00 10 mL, 06:00 10 mL.
Output on the chart: nasogastric drainage 350 mL in total. Wound drain 120 mL in total. No vomiting.
06:00 observations: respiratory rate 20, SpO2 95% on air, blood pressure 102/64 mmHg, pulse 104, alert, temperature 37.4 °C.
Mr Adeyemi says he is thirsty and his mouth is dry. His wound is sore, as expected. The urine in the bag is dark and concentrated.
The catheter tubing is not kinked and the bag hangs on its stand below his bladder, off the floor.

The checklist

Tick what you really did. 10 points, 4 safety-critical, each mapped to a platform of the standards of proficiency [S10] and to sections of the Code [S9]. Our own practice checklist, not the NMC marking criteria.

Cleans hands, introduces self, explains why the chart is being totalled and gains consent to assess him.Platform P1 AccountablePlatform P4 Provide and evaluateCode section 4 Best interestsCode section 7 Communicate
Why it matters
He should know why you are counting his fluids and checking him at this hour.
Safety-criticalConfirms identity with name and date of birth or hospital number, verbally and against the wristband and the fluid balance chart.Platform P4 Provide and evaluatePlatform P6 Safety and qualityCode section 10 RecordsCode section 19 Reduce harm
Why it matters
A balance worked out on the wrong chart leads to the wrong fluid decision.
Total intake so far (mL)
mL

Totals the intake: 1000 mL + 1000 mL + 300 mL = 2300 mL.
Platform P3 Assess and planCode section 10 Records

Why it matters
Every IV bag and every sip counts; a missed entry hides a problem.
Total output so far (mL)
mL

Totals the output: urine 560 + 20 + 15 + 15 + 10 + 10 mL, nasogastric drainage 350 mL, wound drain 120 mL = 1100 mL.
Platform P3 Assess and planCode section 10 Records

Why it matters
Nasogastric and drain losses are output too; leaving them out overstates the balance.
Safety-critical Running balance at 06:00 (mL; a positive number means more in than out)
mL

Works out the running balance: 2300 mL in minus 1100 mL out = 1200 mL positive.
Platform P3 Assess and planPlatform P4 Provide and evaluateCode section 10 RecordsCode section 19 Reduce harm

Why it matters
The balance is what the team uses to judge his fluids; an arithmetic slip changes the decision.
Safety-criticalRecognises the warning pattern: hourly urine falling from 20 to 10 mL, dark urine, thirst, dry mouth and a pulse of 104, and says a positive balance does not mean he is well filled after abdominal surgery.Platform P3 Assess and planPlatform P4 Provide and evaluateCode section 3 Needs assessedCode section 13 Competence limitsCode section 16 Act without delay
Why it matters
After surgery fluid can leave the circulation; falling urine with a raised pulse is an early sign of poor perfusion or kidney injury.
Checks for simple causes first: catheter tubing not kinked, bag below the bladder and off the floor, and asks about pain, nausea and thirst.Platform P3 Assess and planPlatform P4 Provide and evaluateCode section 3 Needs assessedCode section 19 Reduce harm
Why it matters
A blocked or kinked catheter mimics a low urine output and is fixed in seconds.
Safety-criticalScores NEWS2 at 3 from the 06:00 observations, increases the frequency of observations as the chart response requires, and escalates to the doctor now with an SBAR handover using the numbers.Platform P4 Provide and evaluatePlatform P6 Safety and qualityPlatform P7 Coordinate careCode section 8 TeamworkCode section 16 Act without delay
Why it matters
The urine output and his pulse make this a clinical concern beyond the score; the doctor needs to review his fluids now, not at the morning round.
Documents the totals, the hourly urine, the observations, the time of the call and who was told, and keeps measuring every hour.Platform P4 Provide and evaluatePlatform P7 Coordinate careCode section 10 Records
Why it matters
The record shows the trend and the response for the next nurse and the doctor.
Explains to Mr Adeyemi in plain words what you found and what happens next, and offers mouth care for the dry mouth within his sips-only plan.Platform P1 AccountablePlatform P4 Provide and evaluateCode section 1 DignityCode section 7 Communicate
Why it matters
Explaining reduces worry, and mouth care relieves thirst safely while he is on sips only.

NEWS2, worked out

Show the chart, band by band (total it yourself first)

06:00 observations: NEWS2 3
Parameter	Value	Score
Respiration rate	20	0
SpO2, Scale 1	95%	1
Air or oxygen	Air	0
Systolic blood pressure	102	1
Pulse	104	1
Consciousness (ACVPU)	Alert	0
Temperature	37.4 °C	0

Bands from the RCP NEWS2 chart [S11]. The build recalculates every total.

Model walkthrough

Show it, minute by minute (try the station first)

0:00
Read the brief and the chart once. Day 1 laparotomy, catheter, NG on free drainage, drain, IV fluids. Plan: identity, totals, balance, assess, escalate, document.
1:00
Hand rub. Introduce yourself, check name and date of birth against the wristband and the chart.
Say Good morning, Mr Adeyemi. I'm (your name), one of the nurses. I'm going to add up your fluids from yesterday and check how you are. Is that OK?
2:00
Intake: 1000 + 1000 + 300 = 2300 mL. Write it on the chart.
3:30
Output: urine 560 + 20 + 15 + 15 + 10 + 10, NG 350, drain 120 = 1100 mL. Running balance: 2300 minus 1100 = 1200 mL positive.
5:00
Look at the hourly urine: 20, 15, 15, 10, 10 mL, falling. Check the catheter tubing and bag. Ask about thirst, pain and nausea.
Say Are you thirsty? Any sickness, or new pain in your tummy?
6:30
Chart the 06:00 observations on NEWS2: total 3. Say the pattern out loud: positive balance, but falling urine, dark urine, thirst, pulse 104.
8:00
Escalate now with SBAR.
Say I'm (your name), RN on the surgical ward, about Samuel Adeyemi, day 1 after laparotomy. His urine output has fallen from 20 to 10 mL an hour since 02:00 and it's dark. Pulse 104, BP 102/64, NEWS2 3. He's 1200 mL positive, with 350 mL of NG loss. I'm worried he's dry. Please review his fluids now. I'm doing hourly observations meanwhile.
9:30
Tell Mr Adeyemi what is happening. Offer mouth care for the dry mouth.
11:30
After the 3-minute prompt: document totals, hourly urine, observations, time of call and who was told.

Common mistakes

Leaving the nasogastric and drain losses out of the output.
Every loss on the chart counts: urine, NG drainage, drains, vomit.
Reading a positive balance as 'well hydrated, nothing to do'.
Look at the hourly urine and the patient, not just the total.
Waiting for the morning ward round to mention the urine output.
Escalate now with the numbers and the trend.
Not checking the catheter before calling.
Check the tubing and the bag first, then call.
Sums done in your head and not written down.
Write each total on the chart as you go, so it can be checked.

From the official NMC materials

Adult nursing skills stations and their timings: administration of inhaled medication 12 minutes, administration of suppository 10, anti-embolism stockings 10, blood glucose monitoring 8, bowel assessment 8, catheter specimen of urine 8, fine-bore NG tube 12, fluid balance 14, intramuscular injection 12, IV flush and VIP score 12, MSU and urinalysis 12, nutritional assessment 8, oral care plan 8, oxygen therapy 10, pain assessment 6, peak expiratory flow rate 8, pre-operative check 12, pressure area assessment 8, removal of urinary catheter 8, subcutaneous injection 12, wound assessment and ANTT 21. [S4]
You get a prompt 5 minutes before the end of an APIE station and 3 minutes before the end of a skills station. [S5]
Communication is assessed throughout. With a manikin, say your actions and the reasons for them out loud, as you would with a real patient. [S3]
Unsafe practice raises a red flag, and an agreed red flag always means the station is failed. [S3]
The NMC publishes the charts and forms that may be used in the OSCE, including the NEWS2 chart, a hospital medication prescription and administration record, MUST, the Braden risk assessment chart, a phlebitis score, the Bristol stool chart, a fluid balance chart and a pre-operative checklist. [S8]
The NMC's adult mock OSCE checks identity with the person's name plus either their date of birth or hospital number, verbally and against the wristband and paperwork. [S7]
Common mistakes the NMC lists for every station: touching the patient before hand hygiene, not checking allergies, not checking identity, not gaining consent and not finishing in time. [S5]
Saying what you would have done will not overturn a critical fail, and anything you do after the time is up is not assessed. [S5]

The clinical numbers in this station

NEWS2 scores (RCP Chart 1). Respiration rate: 8 or less scores 3, 9-11 scores 1, 12-20 scores 0, 21-24 scores 2, 25 or more scores 3. SpO2 Scale 1: 91% or less 3, 92-93% 2, 94-95% 1, 96% or more 0. Air 0, oxygen 2. Systolic blood pressure: 90 or less 3, 91-100 2, 101-110 1, 111-219 0, 220 or more 3. Pulse: 40 or less 3, 41-50 1, 51-90 0, 91-110 1, 111-130 2, 131 or more 3. Consciousness: alert 0, new confusion, voice, pain or unresponsive (CVPU) 3. Temperature: 35.0 or less 3, 35.1-36.0 1, 36.1-38.0 0, 38.1-39.0 1, 39.1 or more 2. [S11]
NEWS2 response (RCP Chart 4). Total 0: minimum 12-hourly observations. Total 1-4: minimum 4-6 hourly; the registered nurse assesses and decides on more frequent monitoring or escalation. 3 in a single parameter: minimum 1-hourly; inform the medical team. Total 5 or more: minimum 1-hourly; the registered nurse immediately informs the medical team and requests urgent assessment by a clinician with acute care competencies. Total 7 or more: continuous monitoring and emergency assessment by a team with critical care competencies. [S12]
NICE: be bare below the elbow for direct care; take urine samples from a catheter sampling port using an aseptic technique; keep the drainage bag below the level of the bladder and off the floor; flush cannula lumens with sterile sodium chloride 0.9%; clean the skin with chlorhexidine gluconate in 70% alcohol before inserting a peripheral vascular access device. [S17]

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Independent practice. Not affiliated with, endorsed by or approved by the NMC, the test centres or any exam body. Original practice material, no real exam content. No guarantee of a pass. Our checklists are our own, not the NMC marking criteria. Written with AI from the official NMC materials, and checked word for word against them. Practice material, not advice for real patient care: follow your employer's policy and the NMC Code.