The inner cannula of a tracheostomy tube is removed and cleaned, or replaced, at regular intervals mainly to:

Prevent blockage of the airway by dried secretions

Reduce the risk of the tube becoming displaced

Lower the pressure the cuff puts on the trachea

Allow the patient to speak during cleaning

In which ventilator mode does the machine deliver a set number of mandatory breaths timed with the patient's own effort, while allowing spontaneous breaths in between?

Synchronised intermittent mandatory ventilation (SIMV)

Pressure support ventilation (PSV)

Assist-control ventilation (AC)

Continuous positive airway pressure (CPAP)

A patient back from a long operation has cold, pale fingers. The finger probe shows SpO2 84% with a low, irregular waveform, but the patient is alert, talking in full sentences, with pink lips and RR 16/min. What is the most likely explanation for the low reading?

Poor perfusion at the probe site from cold fingers

Anaemia from blood lost during the surgery

Carbon dioxide retention after the anaesthesia

Early hypoxaemia from residual anaesthetic drugs

Respiratory: ventilation, airway and tracheostomy care

14 AIIMS NORCET (Nursing Officer) practice questions on Respiratory: ventilation, airway and tracheostomy care, part of Medical-Surgical Nursing. The first 14 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
The inner cannula of a tracheostomy tube is removed and cleaned, or replaced, at regular intervals mainly to:
1. APrevent blockage of the airway by dried secretions
2. BReduce the risk of the tube becoming displaced
3. CLower the pressure the cuff puts on the trachea
4. DAllow the patient to speak during cleaning
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Answer: A · Prevent blockage of the airway by dried secretions
Secretions dry and crust on the inside of the tube and can narrow or block it completely. The inner cannula can be taken out and cleaned or changed without removing the outer tube, which keeps the stoma secure. This is done at least every shift and more often when secretions are thick. A spare inner cannula and a spare tracheostomy tube are kept at the bedside.
- B: Displacement is prevented by secure ties, not by cleaning the inner cannula.
- C: Cuff pressure is set and checked with a manometer, not changed by the inner cannula.
- D: Speech needs a fenestrated tube or a speaking valve, not removal of the inner cannula.
Question 2 · Easy
In which ventilator mode does the machine deliver a set number of mandatory breaths timed with the patient's own effort, while allowing spontaneous breaths in between?
1. APressure support ventilation (PSV)
2. BAssist-control ventilation (AC)
3. CContinuous positive airway pressure (CPAP)
4. DSynchronised intermittent mandatory ventilation (SIMV)
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Answer: D · Synchronised intermittent mandatory ventilation (SIMV)
In SIMV the ventilator gives a preset number of mandatory breaths, each timed to coincide with the patient's own inspiratory effort. Between them the patient breathes spontaneously at their own depth, often helped by pressure support. It was widely used for weaning because the mandatory rate can be lowered step by step. In assist-control, by contrast, every breath the patient triggers is a full machine breath.
- A: Pressure support only boosts the patient's own breaths and delivers no mandatory rate.
- B: In assist-control every triggered breath is a full set breath, with no purely spontaneous breaths.
- C: CPAP gives a constant pressure throughout the cycle but no mandatory breaths.
Question 3 · Medium
A patient back from a long operation has cold, pale fingers. The finger probe shows SpO2 84% with a low, irregular waveform, but the patient is alert, talking in full sentences, with pink lips and RR 16/min. What is the most likely explanation for the low reading?
1. APoor perfusion at the probe site from cold fingers
2. BAnaemia from blood lost during the surgery
3. CCarbon dioxide retention after the anaesthesia
4. DEarly hypoxaemia from residual anaesthetic drugs
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Answer: A · Poor perfusion at the probe site from cold fingers
A pulse oximeter needs a good pulsatile signal, and cold, vasoconstricted fingers give a weak, irregular waveform with a falsely low SpO2. A comfortable, pink patient talking in full sentences does not fit true desaturation to 84%. The nurse warms the hand or moves the probe to the earlobe or forehead and accepts only a reading with a clean waveform. If the repeat reading is still low, it is treated as real.
- B: Anaemia lowers oxygen content but leaves the SpO2 normal.
- C: CO2 retention causes drowsiness and does not by itself lower a pulse oximeter reading in this way.
- D: Hypoxaemia severe enough to give 84% usually shows as breathlessness, restlessness or cyanosis.
Question 4 · Easy
What cuff pressure is generally recommended for an adult endotracheal or tracheostomy tube?
1. A60 to 80 cmH2O
2. B20 to 30 cmH2O
3. C40 to 50 cmH2O
4. D5 to 10 cmH2O
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Answer: B · 20 to 30 cmH2O
A cuff pressure of 20-30 cmH2O seals the airway without stopping blood flow in the tracheal mucosa. Above about 30 cmH2O the capillaries are compressed, which can lead to ischaemia, ulceration, tracheal stenosis or tracheomalacia. Below 20 cmH2O secretions leak past the cuff into the lungs and raise the risk of VAP. The pressure is checked with a cuff manometer at least once a shift, not judged by feeling the pilot balloon.
- A: Sixty to eighty cmH2O causes ischaemic necrosis of the tracheal wall.
- C: Forty to fifty cmH2O compresses mucosal capillaries and causes tracheal injury.
- D: Five to ten cmH2O allows secretions to leak past the cuff and be aspirated.
Question 5 · Easy
As part of the ventilator-associated pneumonia (VAP) prevention bundle, the head of the bed of a ventilated adult is kept at:
1. AFlat at 0 degrees
2. B10 to 15 degrees
3. C80 to 90 degrees
4. D30 to 45 degrees
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Answer: D · 30 to 45 degrees
Raising the head of the bed to 30-45 degrees reduces reflux of gastric contents and aspiration of secretions that pool above the cuff. Aspiration of these secretions is the main route by which VAP develops. Other parts of the bundle are daily sedation breaks with a check of readiness to wean, oral care with chlorhexidine, peptic ulcer and DVT prophylaxis, and subglottic suction where available. Unless it is contraindicated, the elevation is kept at all times, including during feeds.
- A: Lying flat makes reflux and aspiration much more likely.
- B: Ten to fifteen degrees is too low to prevent aspiration.
- C: Sitting bolt upright for long periods is hard to maintain and raises the risk of sacral pressure injury; it is not the bundle target.
Question 6 · Medium
A ventilated patient's high-pressure alarm sounds. The patient is coughing, and coarse crackles are heard over the trachea. The nurse's first action is to:
1. ASuction the endotracheal tube
2. BSilence the alarm for two minutes
3. CDeflate the endotracheal tube cuff
4. DIncrease the set tidal volume
Answer and explanation in LearnFree account
Question 7 · Medium
A patient rescued from a closed room with a burning charcoal stove reads SpO2 99% on the pulse oximeter but is confused and has a headache. Why is this SpO2 reading unreliable?
1. AConfusion causes movement that falsely raises SpO2
2. BThe probe reads carboxyhaemoglobin as oxyhaemoglobin
3. CSmoke deposits on the skin block the light signal
4. DCarbon monoxide lowers the pulse amplitude at the probe
Answer and explanation in LearnFree account
Question 8 · Medium
The low-pressure (low exhaled volume) alarm of a ventilator sounds. What should the nurse check first?
1. AThe water level in the humidifier
2. BWhether the patient needs suctioning
3. CEvery connection from the tube to the ventilator
4. DThe patient's most recent ABG report
Answer and explanation in LearnFree account
Question 9 · Easy
In an adult, each pass of the suction catheter during endotracheal suctioning should last no longer than:
1. A45 to 60 seconds
2. B60 to 90 seconds
3. C30 to 40 seconds
4. D10 to 15 seconds
Answer and explanation in LearnFree account
Question 10 · Medium
Thirty minutes after PEEP is raised from 5 to 15 cmH2O in a patient with ARDS, the blood pressure falls from 118/74 to 88/56 mmHg. The most likely cause is:
1. AVasodilation caused by improved oxygenation
2. BSpread of sepsis from the lungs
3. CReduced venous return from raised intrathoracic pressure
4. DLeft ventricular failure from fluid overload
Answer and explanation in LearnFree account
Question 11 · Hard
A patient on mechanical ventilation after chest trauma suddenly has repeated high-pressure alarms, SpO2 falling from 96% to 82%, BP 78/50 mmHg, HR 138/min, absent breath sounds on the left, and a trachea shifted to the right. A suction catheter passes easily and returns little. What is the most likely cause?
1. APatient biting on the endotracheal tube
2. BMucus plug in the right main bronchus
3. CEndotracheal tube slipped into the right main bronchus
4. DLeft tension pneumothorax
Answer and explanation in LearnFree account
Question 12 · Hard
A 60-kg adult on volume-control ventilation (rate 22/min, tidal volume 550 mL) has this ABG: pH 7.53, PaCO2 27 mmHg, HCO3- 23 mEq/L, PaO2 96 mmHg (normal pH 7.35-7.45, PaCO2 35-45 mmHg, HCO3- 22-26 mEq/L). Which interpretation and likely cause fit best?
1. AMetabolic acidosis with compensatory hyperventilation
2. BMetabolic alkalosis from nasogastric drainage
3. CRespiratory acidosis from too low a set rate
4. DRespiratory alkalosis from excess minute ventilation
Answer and explanation in LearnFree account
Question 13 · Hard
A patient with a cuffed tracheostomy tube with an inner cannula suddenly becomes distressed, with SpO2 80%, no air felt at the tube opening and no misting. A suction catheter will not pass beyond a few centimetres. The nurse's first action is to:
1. ADeflate the cuff and wait for the doctor
2. BRemove the inner cannula and check it for a block
3. CIncrease the oxygen flow to 15 L/min
4. DInstil 5 mL of saline down the tube
Answer and explanation in LearnFree account
Question 14 · Medium
Before suctioning a ventilated adult, the nurse gives 100% oxygen for 30 to 60 seconds. The purpose is to:
1. APrevent hypoxaemia caused by the suctioning
2. BLoosen thick secretions in the airway
3. CStop the patient coughing as the catheter passes
4. DReduce the risk of bacterial contamination
Answer and explanation in LearnFree account

Respiratory: ventilation, airway and tracheostomy care

The inner cannula of a tracheostomy tube is removed and cleaned, or replaced, at regular intervals mainly to:

In which ventilator mode does the machine deliver a set number of mandatory breaths timed with the patient's own effort, while allowing spontaneous breaths in between?

A patient back from a long operation has cold, pale fingers. The finger probe shows SpO2 84% with a low, irregular waveform, but the patient is alert, talking in full sentences, with pink lips and RR 16/min. What is the most likely explanation for the low reading?

What cuff pressure is generally recommended for an adult endotracheal or tracheostomy tube?

As part of the ventilator-associated pneumonia (VAP) prevention bundle, the head of the bed of a ventilated adult is kept at:

A ventilated patient's high-pressure alarm sounds. The patient is coughing, and coarse crackles are heard over the trachea. The nurse's first action is to:

A patient rescued from a closed room with a burning charcoal stove reads SpO2 99% on the pulse oximeter but is confused and has a headache. Why is this SpO2 reading unreliable?

The low-pressure (low exhaled volume) alarm of a ventilator sounds. What should the nurse check first?

In an adult, each pass of the suction catheter during endotracheal suctioning should last no longer than:

Thirty minutes after PEEP is raised from 5 to 15 cmH2O in a patient with ARDS, the blood pressure falls from 118/74 to 88/56 mmHg. The most likely cause is:

A 60-kg adult on volume-control ventilation (rate 22/min, tidal volume 550 mL) has this ABG: pH 7.53, PaCO2 27 mmHg, HCO3- 23 mEq/L, PaO2 96 mmHg (normal pH 7.35-7.45, PaCO2 35-45 mmHg, HCO3- 22-26 mEq/L). Which interpretation and likely cause fit best?

A patient with a cuffed tracheostomy tube with an inner cannula suddenly becomes distressed, with SpO2 80%, no air felt at the tube opening and no misting. A suction catheter will not pass beyond a few centimetres. The nurse's first action is to:

Before suctioning a ventilated adult, the nurse gives 100% oxygen for 30 to 60 seconds. The purpose is to: