Ventilator Trouble shootingPresented by Lily To & James Lindsey

Ventilator Troubleshooting• Involves identification & resolution of a technical problem• A problem is a situation in which one finds oneself in that can not be immediately corrected

Solving Ventilator Problems• Access situation • Gather & analyze pertinent data• This information should point to a number of potential solutions• A solution should be tried – with making an observation of the patient’s response• A positive response leads to correction of the problem• A negative response – undo what was tried – find out why it didn’t work before attempting a new solution• Determining cause of the problem – helps prevent the problem from reoccurring

Protecting the Patient• Always ensure patient safety• When alarm is triggered – check patient first • Look for LOC, increased WOB, use of accessory muscles, auscultation, SpO2, heart rate, skin color, diaphoresis• Distress - bag patient, if necessary• Check alarm & alarm settings

Ventilator – Related Causes• System leaks• Disconnected circuit• Low FiO2

Patient – Ventilator asynchrony – Causes• Artificial airway problems• Bronchospasm• Secretions• Pulmonary edema• Pulmonary embolism• Dynamic hyperinflation• Abnormal respiratory drive• Body positioning• Pneumothorax• Anxiety

Improper Settings

• Incorrect support mode

• Sensitivity

• Flow

• Time cycled

• PEEP

Identifying Patient Distress

• Notice when patient is “fighting the vent” or asynchrony

• Signs include: tachypnea, nasal flaring , diaphoresis, use of accessory muscles, retractions, paradoxal chest abdomen movement, abnormal breath sounds, tachycardia, arrhythmia, hypertension

Sudden Causes of Respiratory Distress

Common Patient – Related Problems

• Airway problems• Kinked ET tube, biting• Displacement of tube in right lobe or upward• Rupture of an artery• Fistula obstructed ET tube

• Pneumothorax• Look for increased work of breathing, nasal flaring, use of accessory muscles, absence of breath sounds, uneven chest movement & cardiovascular assessment

• Bronchospasm• Signs include:• dyspnea, wheezing, increased work of breathing, paradoxical chest/abdomen movement,

retractions and increased RAW

• Secretions• Evaluation can lead to differentiate problems• Dry secretions – insufficient humidification?• Copious amounts – pulmonary edema?• Detect infection?

Pneumothorax

Common Patient – Related Problems

• Pulmonary Edema• Cardiogenic pulmonary edema

• Sudden – thin, frothy, white to pink secretions. Follow through with additional testing – ECG, Bp, JVD and Hx of heart disease• Treatment includes medications to reduce preload and afterload (lasix), increase contractility (Lanoxin)

• Non-cardiogenic pulmonary edema• Not sudden – increase in pulmonary capillary permeability (treatment similar to above)

• Dynamic Hyperinflation • Auto-PEEP causes dynamic hyperinflation – leads to difficulty triggering ventilator & increased work of breathing• Causes hypertension and reduced cardiac output• Suspected when flow does not return to baseline in flow-time curve.• Treatment: reduce TI, VE and correct RAW

• Abnormalities in Respiratory Drive• Decrease is result of heavy sedation, neurological disorders, neuromuscular blockage• Increase is result of pain, anxiety, peripheral sensory stimulation, medications and improper ventilator settings

Common Patient – Related Problems

• Changes in Position• Can cause accidental extubation• Alter oxygenation by bending, twisting circuit• Cause mucous plugging

• Drug Induced Distress• Can cause respiratory distress & maybe failure

• Abdominal Distention• Distention - can be associated with other disorders that introduce air into the stomach (ascites, GI bleed, liver & kidney problems)

• Pulmonary Embolism• Emergency • Leads to asynchrony • Sudden onset – hypoxemia • Patient presents with bilateral breath sounds, increased WOB, elevated HR, Bp and RR• Increasing flow and FiO2 does nothing to correct• Treat with increased respiratory rate• Capnography – helps us see – reduced VT & CO2

Ventilator – Related Problems

• Leaks – cuff, circuit• Alarm activates• Low/high pressure• Low minute ventilation

• Inadequate Oxygenation• SpO2 alarm• Signs – hypoxemia

• Inadequate Ventilator Support• Causes increased work of breathing, respiratory acidosis & hypoxemia• Leads to asynchrony

• Sensitivity• Causes auto-triggering –setting too low - high pressure, patient can not trigger

• Flow Setting• Air starvation – correct by increasing flow or changing flow pattern

• Other Problems• Auto-PEEP – makes vent more difficult for patient to trigger a breath – correct by increasing E-time• PSV - may cause asynchrony with certain disorders and if it is set too low

Drager V500

Puritan Bennet 840

Normal Alarm Settings:

• VT: high, 200ml above setting – low, 100ml below setting

• Pressure: high, 10cmH2O above PIP – low, 5cmH2O below PIP

• Rate: high, 10 bpm above setting – low, 5 bpm below setting

• Flow: high, 2L above setting – low, 2L below setting

• Apneic: 20 seconds

• FiO2: high, 5% above setting – low, 5% below setting

Common Alarm Situations

Common Alarm Situations

Low Pressure Alarm Causes:• Patient disconnected

• Circuit leaks – inspiratory/expiratory circuits

• Ventilator related disconnections• Humidifiers, filters, water traps, nebulizers, closed circuit

catheter

• Temperature monitors

• Exhalation valve leak• Cracked, unseated, improperly connected

• Airway leaks• Improper cuff inflation• Cut hole in pilot balloon/ cuff• Migration of ET tube

• Chest tube leaks

*Most often activated by leaks*

High Pressure Alarm Causes:• Coughing

• Biting, kinking, positioning of ET tube

• Herniation of ET tube/cuff

• Increased airway resistance (secretions, edema, bronchospasm)

• Decreased compliance (pneumothorax, pulmonary embolism)

• Patient – ventilator asynchrony

• Accumulation of water in circuit

• Kinking in inspiratory circuit

• Malfunction with inspiratory/expiratory valves

Additional Alarms

• Low PEEP/CPAP• Activated when airway pressure falls below desired baseline during PEEP/CPAP• Causes include: leaks or by active inspiration

• Apnea alarm• 20 seconds• Causes: patient apneic or disconnection, leaks, sensitivity setting

• Low-Source Gas Pressure/ Power Alarm• If gas or power source fails

• I:E Ratio Alarm• Most ventilators do not allow I:E ratio to be set less than 1:1• Causes: flow set too low for desired VT delivery• I:E – may change with a change in waveform (constant to descending - lengthens TI in VC)

Additional Alarms

• High PEEP/CPAP alarms• Causes are similar to those of high pressure• flow-cycle modes , check for leaks

• Low VT, low VE or low flow alarms• Causes are similar to low pressure alarms• Determine if spontaneous ventilation has decreased• Check all alarms• Check flow sensors, disconnection/malfunction

• High VT, high VE or high flow alarms• Check sensitivity setting, causes auto-triggering• Check patient for possible cause of increased VE• Check alarm settings• If nebulizer in use, reset alarm until treatment is completed• Check flow sensors, contamination/malfunction

• Low/high FiO2 alarms• Check gas source• Check built-in oxygen analyzer is functioning properly

Flow Sensor

Nebulizer

Use of Ventilator Graphics to Identify Ventilator Problems

• Ventilator graphics can alert of abnormalities before obvious signs appear

• Flow-time & Pressure-time graphs are used for accessing patient triggering, flow starvation, auto-PEEP, I:E time, flow pattern, plateau time, rise times and asynchrony

• Volume-time graph accesses auto-PEEP

• Pressure-Volume loop accesses leaks, overdistention, increased RAW, asynchrony and patient triggering

• Flow-Volume loops are used to access obstructive/restrictive lungs, the effects of bronchodilators and leaks

• Waveform ringing in Flow-time & Pressure-time Occurs when flow & pressure are very high at a beginning of a breath – a result of oscillation of air at beginning of a breath

Flow-Volume

Use of Ventilator Graphics to ID Problems

Leaks – low pressure, low volume , low minute ventilation or apnea will trigger alarm

Pressure-Volume Loop Flow-Volume Loop

Flow-time curve

Volume-time curve

LeakLeak

Auto-PEEP, air trapping

Overdistention

Examples of additional graphic curves

Pressure-Volume Loop

Overdistention

Correct: increase E-time Correct: reduce volume, pressure

Obstruction: administer bronchodilator

Unexpected Ventilator Responses

Unseated/Obstructed Expiratory Valve• Blocked or unseated valve, unable to get expiratory pause – plateau pressure

High Tidal Volume Delivery• Occurs with small volume nebulizer (SVN)• Flowmeters can add extra flow – can increase tidal volume

Excessive CPAP/PEEP• Eliminate leaks – causes application of high flow to maintain CPAP/PEEP

Nebulizer Impairment of Patient’s Ability to Trigger PSV• Nebulizer makes it more difficult for patient to trigger ventilator • Usually occurs with external gas sourced nebulizer• Use manufacturer’s nebulizer if provided

Flowmeter 840

Is patient demandVE increased

Is vent Auto-triggering

Is a nebulizerIn use

Is flow sensormalfunctioning

Is alarm settoo low

Check operatorsManual/contact

manufacturer

Check cause of increased VE demandto determine if change is needed

yes

yes

1. Check sensitivity setting2. Check the MMV setting

yes Adjust vent settings untiltreatment is completed

yes1. Clean & calibrate sensor 2. Clear sensor line3. Check its function and replace if needed

yes Adjust alarm setting

Increased VT, VE or rate alarm

No

1. Check machine for sensitivity level for auto-triggering2. Check for cause of increased VE

3. Ensure alarms have been properly set4. External nebulizer used; reset alarm until treatment is completed5. Check flow sensors for calibrations, contamination or malfunction

Please Note always start by checking patient’s stability and is adequately ventilated

Is patient disconnected

Is there a leak in the circuit

Is there a cuff leak

Is there a chest tube leak

Is proximal airway pressure line obstructed

Is the flow sensor malfunctioning

Alarm set inappropriately

Check manual/contact trained specialist

yes Reconnect

Repair/replace circuit

Reinflate cuff/check it’s pressure –replace tube if necessary

No

Contact physician/monitor pt

Clear the line

1. Clear sensor & recalibrate it2. Clear sensor line & recheck3. Check sensor function & replace sensor if necessary

yes

yes

Reset

yes

yes

yes

yes

Low pressure. Low PEEP, low VT, low VE

1. Check for disconnection2. Check for leaks in ventilator, circuits, airway & chest tubes3. Check proximal pressure line is connected & unobstructed4. Low-pressure maybe accompanied by a low minute volume or low tidal volume alarm

Is artificial airway completely obstructedCan it be cleared

Is pt coughing

Are there secretions in the airway

Is the circuit obstructed

Is ET tube being bitten

Is the position of artificial airway altered

Is the Raw increased or compliance increased

High pressure, High PEEP alarms

Change artificial airway

Suction or relieve irritation

1. Drain condensation 3. kinks in ventilator circuit

2. Check water traps

Insert a bite block

Reposition artificial airway

Suction pt

Assess & Correct1. Secretions 5. Pulmonary edema2. Bronchospasm 6. Pneumothorax3. Mucosal edema 7. Pleural effusion 4. Pneumonia 8. Other

No

yes

yes

yes

yes

yes

yes

yes

Continued

Continued - High pressure, High PEEP

Is pt breathing asynchronously

Auto-PEEP present

Is exhalation valve malfunctioning

Is the venting pressure too high

Is alarm set too low

Check for possible causesET cuff blocking the end of

the artificial airway

1. Check inspiratory gas flow 4. Check mode of ventilation

2. Check sensitivity 5. Consider sedation3. Check vent parameters

1. Check & treat for increased Raw (suction, bronchodilator)2. Increase flow to shorten Ti and increase TE 3. Decrease VE

Fix or replace valve

Reduce pressure

Increase alarm setting

No

yes

yes

yes

yes

yes

1. Pt coughing; determine if secretions have built up in airway or pt is biting ET tube2. Check for kinks or displacement of ET tube and circuit3. Check to see if RAW has increased or CL has decreased4. Check is patient is breathing synchronously with vent5. Determine if there is auto-PEEP has developed6. Make sure the expiratory filter & expiratory valve are functioning properly.

Is an adverse ratio desired

Is vent time cycled

Is volume being used with set flow too low

Is volume being used with a set volume too high

Is the rate too high

Is vent flow reduced due to mechanical problem, increased Raw, or decreased compliance

Change mode or VE parameters

I:E Indicator

No

Activate inverse ratio

Decrease inspiratory time

Increase flow

Decrease volume

Decrease rate

Eval patient & vent’s performance and correct problem

yes

yes

yes

yes

yes

yes

1. Usually indicates I:E ratio greater than 1:12. If inverse is goal: disable I:E ratio limit or ignore alarm3. If normal I:E desired: check alarmIf increased RAW/decreased CL has resulted in lower flow, tx causeIf flow is too low for desired VT, increase flow or change waveform

Is an actual apneic episode occurring

Is the alarm setting appropriate

Is vent insensitive to patient effort

Is there a leak

Is flow or pressure sensor faulty

Check operator’s manual/contact trained technician

Apneic Alarm

Readjust vent support

Reset alarm

Reset the sensitivity

See low pressure alarms

Clean recalibrate, check & replace sensor if necessary

yes

yes

yes

yes

No

yes

1. Is patient apneic2. Check for leaks3. Check sensitivity to make sure vent can detect patient effort4. Check alarm time interval and volume setting

References:

AARC Clinical Practice Guidelines Basic Clinical Lab Competencies for Respiratory Care, 5th Ed., White Cardiopulmonary Anatomy & Physiology, Essentials of Respiratory Care, 6th Ed, Des Jardins Egan’s Fundamentals of Respiratory Care, 10th Ed, Kacmarek, Stoller, Heuer emedicine.com Equipment Theory for Respiratory Care, 4th Ed., White John Hopkins Medical Health Library, hopkinsmedicine.org MayoClinic.com Mechanical Ventilation Physiological and Clinical Applications, 5th Ed 2014, Pilbeam Medline Plus, 2013 Medscape NCBI, National Center for Biotechnology Information, U.S. National Library of Medicine, 2013 NDNR, Naturopathic Doctor News & Review, 2013 RC Journal Respiratory Care, Principles & Practice, 2nd Ed, Hess The Essentials of Respiratory Care, 4th Ed, Kacmarek