1
Look at the patient first
Assess mental status, chest rise, work of breathing, color, perfusion, blood pressure, SpO₂ waveform, and immediate distress.
PulmTools Resource
Mechanical Ventilation Troubleshooting
A practical ventilator troubleshooting reference for high peak pressure, high plateau pressure, auto-PEEP, low exhaled tidal volume, leaks, dyssynchrony, ventilator alarms, and sudden desaturation on mechanical ventilation.
High peak pressureHigh plateau pressureAuto-PEEPVent alarmsLeaksDyssynchrony
Bedside priority: When a ventilated patient deteriorates, assess the patient first, then the tube/circuit, ventilator data, and waveforms. Do not troubleshoot the screen while the patient is unstable.
2
Check the circuit and tube
Follow oxygen source, ventilator, circuit, humidifier/filter, patient connection, cuff, tube depth, and suction catheter passage.
3
Read the ventilator data
Compare set vs delivered VT, exhaled VT, minute ventilation, peak, plateau, PEEP, FiO₂, ETCO₂, and alarm history.
4
Use waveforms
Flow, pressure, and volume waveforms often reveal air trapping, obstruction, leaks, dyssynchrony, or inadequate flow.
5
Fix and reassess
After each intervention, reassess the patient, ventilator numbers, waveforms, oxygenation, ventilation, and hemodynamics.
Troubleshooting by problem
Common mechanical ventilation problems
Use these patterns to organize bedside thinking. Many ventilator problems overlap, so reassess the patient and waveforms after each intervention.
Oxygenation problems
Signal: Low SpO₂, falling PaO₂, rising FiO₂ need, cyanosis, or worsening work of breathing
Common causes
- Atelectasis or derecruitment
- Worsening pneumonia, edema, ARDS, or shunt physiology
- Low PEEP or inadequate mean airway pressure
- Circuit disconnect, leak, or oxygen source problem
- Right mainstem intubation or tube migration
Bedside actions
- ✓Check patient first: pulse ox waveform, perfusion, mental status, chest rise, and hemodynamics.
- ✓Confirm oxygen source, FiO₂ delivery, circuit connection, humidifier, and ventilator function.
- ✓Assess breath sounds, tube depth, suction need, and recent position changes.
- ✓Consider recruitment/PEEP strategy, CXR, ABG/VBG, and escalation based on clinical severity.
Ventilation problems
Signal: High PaCO₂, rising ETCO₂, low minute ventilation, low tidal volume, or hypoventilation alarms
Common causes
- Low set respiratory rate or tidal volume
- Increased dead space or severe V/Q mismatch
- Air trapping limiting effective ventilation
- Weak drive or fatigue on spontaneous modes
- Leak, disconnect, obstruction, or poor synchrony
Bedside actions
- ✓Confirm delivered VT, exhaled VT, minute ventilation, ETCO₂ trend, and ABG/VBG when needed.
- ✓Review mode, set rate, VT or pressure, inspiratory time, pressure support, and trigger settings.
- ✓Look for obstruction, auto-PEEP, circuit leak, and patient-ventilator dyssynchrony.
- ✓Adjust ventilation thoughtfully while protecting pressures, expiratory time, and lung-protective goals.
High peak pressure
Signal: Peak inspiratory pressure rises while plateau pressure may be normal or elevated
Common causes
- Secretions, mucus plug, bronchospasm, or biting the tube
- Kinked ETT, kinked circuit, water in tubing, or clogged HME/filter
- High inspiratory flow or airway resistance
- Reduced compliance if plateau is also high
- Coughing, agitation, dyssynchrony, or patient effort
Bedside actions
- ✓Compare peak pressure with plateau pressure when clinically appropriate and safe.
- ✓If peak is high but plateau is normal, think resistance: suction, bronchodilator need, kink, bite block, or circuit obstruction.
- ✓If both peak and plateau are high, think compliance, lung volume, abdominal pressure, pneumothorax, edema, ARDS, or atelectasis.
- ✓Treat the patient, not the number: reassess chest rise, breath sounds, oxygenation, hemodynamics, and waveform changes.
High plateau pressure
Signal: Elevated plateau pressure during passive ventilation suggests increased alveolar pressure / reduced compliance
Common causes
- ARDS, pulmonary edema, pneumonia, atelectasis, or consolidation
- Pneumothorax or pleural process
- Excessive tidal volume or overdistension
- High intrinsic PEEP or breath stacking
- Elevated abdominal pressure, obesity, or positioning effects
Bedside actions
- ✓Confirm patient is passive enough for an accurate inspiratory hold measurement.
- ✓Review VT based on predicted body weight and lung-protective strategy.
- ✓Assess driving pressure, PEEP, CXR findings, lung mechanics, and hemodynamics.
- ✓Escalate promptly if high plateau pressure occurs with hypotension, sudden desaturation, or unilateral breath sounds.
Auto-PEEP / breath stacking
Signal: Expiratory flow fails to return to baseline, air trapping, hypotension, high total PEEP, or difficult triggering
Common causes
- Obstructive lung disease such as asthma or COPD
- Respiratory rate too high
- Inspiratory time too long or expiratory time too short
- Large VT or excessive minute ventilation demand
- Secretions, bronchospasm, or narrow/artificial airway resistance
Bedside actions
- ✓Inspect the flow-time waveform: expiratory flow should return to baseline before the next breath.
- ✓Increase expiratory time by reducing RR, shortening inspiratory time, adjusting flow, or reducing VT when appropriate.
- ✓Treat bronchospasm and secretions; reassess resistance and patient comfort.
- ✓If severe hypotension or dynamic hyperinflation occurs, disconnecting briefly to allow exhalation may be an emergency maneuver under trained supervision.
Low exhaled tidal volume / leak
Signal: Low exhaled VT alarm, low minute ventilation, audible leak, poor cuff seal, or inconsistent delivered volume
Common causes
- Cuff leak or underinflated cuff
- Circuit disconnect or loose connection
- Chest tube leak, bronchopleural fistula, or large airway leak
- Noninvasive mask leak or poor interface fit
- ETT size/depth issue or tube damage
Bedside actions
- ✓Check the full circuit from ventilator outlet to patient connection.
- ✓Assess cuff pressure, pilot balloon, tube position, and audible leak.
- ✓Compare inspired VT and exhaled VT trends.
- ✓Escalate if leak causes inadequate ventilation, aspiration risk, or inability to maintain oxygenation.
Dyssynchrony / double-triggering
Signal: Patient fighting the ventilator, double breaths, accessory muscle use, discomfort, or abnormal waveforms
Common causes
- Pain, anxiety, fever, acidosis, hypoxemia, or high respiratory drive
- Inadequate flow, VT, inspiratory time, or pressure support
- Trigger sensitivity too insensitive or too sensitive
- Auto-PEEP making triggering difficult
- Mode mismatch for patient demand or disease state
Bedside actions
- ✓Assess pain, sedation, oxygenation, acid-base status, and patient respiratory drive first.
- ✓Review trigger, flow, inspiratory time, pressure support, rise time, cycling, and mode.
- ✓Use waveforms to identify ineffective triggering, flow starvation, double-triggering, or delayed cycling.
- ✓Avoid reflexively deepening sedation before fixing correctable ventilator-patient mismatch.
Sudden desaturation on the ventilator
Signal: Abrupt SpO₂ drop, alarm cluster, new hypotension, loss of chest rise, or acute distress
Common causes
- Displacement: tube migration, extubation, mainstem intubation
- Obstruction: mucus plug, kink, bite, clogged filter
- Pneumothorax or acute lung process
- Equipment: disconnect, oxygen failure, ventilator/circuit issue
- Stacking/auto-PEEP or severe bronchospasm
Bedside actions
- ✓Use a structured DOPE-style check: Displacement, Obstruction, Pneumothorax, Equipment.
- ✓Manually ventilate with BVM and 100% oxygen if ventilator/circuit failure is suspected or the patient is unstable.
- ✓Check tube depth, chest rise, breath sounds, suction catheter passage, and circuit connections.
- ✓Call for help early and escalate rapidly for hypotension, absent breath sounds, or suspected tension pneumothorax.
Alarm guide
Ventilator alarms: quick bedside framing
| Alarm | Likely meaning | Fast check |
|---|---|---|
| High pressure alarm | Resistance, compliance problem, coughing, secretions, kink, bronchospasm, or breath stacking | Patient → tube/circuit → suction/bronchospasm → peak vs plateau → waveform |
| Low pressure alarm | Disconnect, leak, cuff issue, circuit problem, or inadequate patient connection | Connections → cuff pressure → exhaled VT → circuit integrity → patient chest rise |
| Low minute ventilation | Low VT, apnea, leak, fatigue, weak effort, low set rate, or disconnect | Mode/rate → exhaled VT → leak → patient effort → ABG/VBG/ETCO₂ trend |
| High respiratory rate | Pain, anxiety, hypoxemia, acidosis, fever, dyssynchrony, or inadequate support | Patient comfort → oxygenation → acid-base → trigger/support → waveform |
| Apnea alarm | Low drive, oversedation, fatigue, neurologic change, or spontaneous mode mismatch | Patient responsiveness → backup ventilation → sedation/meds → mode safety |
Escalation cues
When to call for help immediately
Sudden desaturation with hypotension, absent breath sounds, or suspected pneumothorax.
Unable to ventilate or oxygenate despite BVM, suction, circuit check, and basic interventions.
Severe auto-PEEP, breath stacking, or obstructive crisis with hemodynamic compromise.
Persistent high plateau pressure with worsening oxygenation or shock physiology.
New severe dyssynchrony, agitation, or high respiratory drive with worsening gas exchange.
Any neonatal or pediatric ventilated patient with rapid deterioration or limited reserve.
Related PulmTools resources and calculators
Pair this troubleshooting guide with ventilator modes, ARDSNet, predicted body weight, oxygenation tools, and post-intubation airway resources.