Bedside Topline

What It Does: Delivers breaths and sets pressure, volume and flow. When a ventilated patient deteriorates, first find whether the patient, the tube, the circuit or the machine is the cause.
Key Settings & Targets: Plateau pressure at or below 30 cm H₂O (ARDS)
Tidal volume 4–8 mL/kg predicted body weight, usually 6 (ARDS)
Cuff pressure 20–30 cm H₂O
Check Every Hour: Chest rise, breath sounds, SpO₂, EtCO₂ waveform, peak and plateau pressure, exhaled volume, and any alarm history.
Top Alarm → First Move: High peak pressure: check patient, suction, check tube kinks and bite, then disconnect and bag if the patient worsens.
Never: Silence an alarm without finding its cause. Leave a disconnected patient without bagging.
Escalate Now If: SpO₂ falls despite more FiO₂; blood pressure falls with rising peak pressure (think tension pneumothorax); or the EtCO₂ waveform disappears.

Overview & How It Works

A mechanical ventilator pushes positive-pressure breaths through an endotracheal tube (ETT) or tracheostomy. On every breath it measures pressure, flow and volume. An alarm means the measured breath is not the set breath, or the patient is breathing in a way the machine does not expect. Most sudden alarms come from the patient, the tube or the circuit. Not the machine.

Key Components

Component	Where It Sits	What It Does
Ventilator console	Bedside or transport unit	Mixes gas, sets mode and breath type, and measures pressure and flow
Inspiratory and expiratory limbs	Patient circuit	Carry gas to and from the patient; water traps collect condensate
Humidifier or heat-moisture exchanger	Inspiratory limb	Conditions gas; a filter adds dead space and resistance
ETT or tracheostomy with cuff	Patient airway	Delivers gas; the cuff seals the airway
Flow sensor and pressure line	Y-piece	Source of the pressure and flow waveforms and most alarms
Exhalation valve and PEEP valve	Expiratory limb	Releases gas and sets positive end-expiratory pressure (PEEP)

Flow Path

Gas source (wall oxygen and air, or compressor) enters the ventilator and blender.
Gas passes through the inspiratory limb and humidifier to the Y-piece with the flow sensor.
Gas enters the ETT and the lungs.
Expired gas returns through the expiratory limb, passes the exhalation valve (PEEP is set here) and exits the ventilator.

Key Point: First question on any alarm: is the patient breathing and oxygenating? Check the patient before you look at the screen.

Physiology & Hemodynamic Effects

What It Does

Parameter	Effect	Why It Matters
Intrathoracic pressure	↑ during each breath	Reduces venous return; blood pressure can fall, especially with high PEEP or auto-PEEP
Lung volume at end-expiration	↑ with PEEP	Recruits collapsed alveoli and improves oxygenation in ARDS, but adds lung stretch
Lung stretch	↑ with tidal volume and driving pressure	Ventilator-induced lung injury; in pooled ARDS trial data, driving pressure was the ventilator variable most associated with survival
Air trapped at end-expiration	↑ with auto-PEEP	Hyperinflation, higher work of breathing, lower blood pressure and missed triggers
CO₂ elimination	↓ when minute ventilation falls	PaCO₂ rises; the EtCO₂ trend shows it before the blood gas does
Oxygenation	↑ with FiO₂ and PEEP	Falls when the tube is displaced, the circuit leaks or the lung becomes stiffer

What It Depends On

Preload: low volume status makes positive pressure hit blood pressure harder.
Compliance and resistance: stiff lungs (ARDS, pneumothorax, abdominal distension) and narrow airways (secretions, bronchospasm) change every pressure you read.
Patient effort: sedation, pain and paralysis all reshape the waveform.
Tube and circuit: position, cuff seal, kinks and leaks.

Clinical Pearl: Auto-PEEP is pressure left in the lungs at end-expiration. Most screens don't show it as a single number. Look for expiratory flow that has not returned to zero. To measure it, use an end-expiratory hold in a passive patient.

Types, Modes & Configurations

Mode	What the Machine Targets	What to Watch
Volume control (assist-control)	Set tidal volume and flow; pressure varies	Peak pressure rises with secretions or stiffer lungs; read the plateau
Pressure control	Set inspiratory pressure; volume varies	Exhaled volume falls when compliance drops or the circuit leaks
Pressure support	Patient sets rate and timing; machine supports each breath	Patient-ventilator mismatch: check trigger sensitivity and cycling
SIMV (mandatory plus spontaneous)	Mandatory breaths at set rate; spontaneous breaths between them	A mandatory breath landing on top of an effort can stack breaths

Settings That Change the Waveform

Tidal volume (volume modes): the volume you set is the volume delivered, and that sets peak and plateau pressure.
Inspiratory flow and time: a short inspiratory time or low flow cuts expiration short and promotes auto-PEEP.
Respiratory rate: a higher rate leaves less expiratory time. That is the main driver of dynamic hyperinflation, as the 2026 Marini review on airflow obstruction describes.
PEEP: it sets the end-expiratory baseline.
Trigger sensitivity: too insensitive and you miss efforts. Too sensitive and the machine auto-triggers.

Note: Mode names change from one manufacturer to the next. Read the operator's manual for the device at the bedside.

Indications, Contraindications & Evidence

Indications

Acute respiratory failure with hypoxemia or hypercapnia that does not respond to noninvasive support or that requires a secure airway.
Acute respiratory distress syndrome (ARDS): use lung-protective settings (tidal volume 4–8 mL/kg predicted body weight, usually 6, and plateau pressure at or below 30 cm H₂O; ARDS Network 2000, Fan 2017).
Inability to protect the airway or clear secretions, with or without a rising PaCO₂.

Cautions: Treat or Adjust, Do Not Withhold Ventilation

Condition	What to Do
Pneumothorax, tension or simple (untreated)	Ventilate if the patient needs it, and decompress or drain at the same time per protocol. Positive pressure can enlarge a simple pneumothorax and turn it into a tension pneumothorax (general teaching). The Leigh-Smith and Harris review (2005) covers the recognition and decompression of tension pneumothorax.
Severe hypotension	Resuscitate (fluid, vasopressor) in parallel with intubation, and anticipate hypotension after intubation. Use the lowest rate and PEEP the protocol allows while oxygenation is maintained, and recheck blood pressure after each change.
Severe bronchospasm with auto-PEEP	Treat the bronchospasm, use a slower rate and longer expiratory time, and disconnect briefly to deflate the lungs if the patient is unstable.

Positive pressure cuts venous return. Blood pressure can fall with it.
A clean waveform does not rule out hypoxemia, a displaced tube or a pneumothorax.
Waveforms and calculated values are unreliable while the patient coughs, fights the ventilator or has a leaking cuff. Don't trust the numbers then.

Key Evidence

Trial or Guideline (Year)	Population	Bottom Line
ARDS Network (2000)	ARDS, randomized	Tidal volume 6 mL/kg predicted body weight with plateau pressure at or below 30 cm H₂O improved survival compared with 12 mL/kg
Amato (2015)	ARDS, pooled trial data	Driving pressure (plateau minus PEEP) was most strongly associated with survival; each 1 SD (about 7 cm H₂O) increase raised mortality risk
Taran (2026)	Acute brain injury, secondary analysis	Higher driving pressure was associated with ICU mortality; the association was similar for static driving pressure
Fan (ATS/ESICM/SCCM, 2017)	ARDS, guideline	Tidal volume 4–8 mL/kg predicted body weight and plateau pressure below 30 cm H₂O
ATS/ACCP (2017)	Ventilated adults over 24 hours	Protocolized ventilator liberation; cuff leak test before extubation in selected patients (conditional recommendation)

Warning: Here's the trap: the most missed pitfall is an untreated pneumothorax. Positive pressure can turn a simple one into a tension pneumothorax. Listen to both sides of the chest before and after intubation.

Setup, Settings & Targets

Parameter	Typical Target	If Below	If Above
Plateau pressure	At or below 30 cm H₂O (ARDS)	—	Lower tidal volume in 1 mL/kg steps toward 4 mL/kg predicted body weight (ARDS Network protocol); check compliance and chest
Driving pressure (plateau minus PEEP)	As low as feasible (protocol-dependent)	—	Lower tidal volume or adjust PEEP per protocol
Tidal volume	ARDS: 4–8 mL/kg predicted body weight, usually 6 (typical; follow institutional protocol). Non-ARDS: 6–8 mL/kg (typical)	Check leak and exhaled volume	Lower tidal volume; check plateau
ETT cuff pressure	20–30 cm H₂O	Add air; check for leak and aspiration	Remove air; check for tracheal injury
PEEP	Per protocol or ARDS table	Check oxygenation trend	Check blood pressure and driving pressure
FiO₂	Lowest that meets the ordered SpO₂ goal	Check tube, circuit and lung first	Wean as tolerated

Initial Settings

ARDS: volume control at 4–8 mL/kg predicted body weight, usually 6 (ARDS Network 2000; Fan 2017). Keep plateau at or below 30 cm H₂O. Set PEEP and FiO₂ per the ARDS table or protocol.
Non-ARDS adult (typical starting point): volume control at 6–8 mL/kg predicted body weight, rate about 12–20, PEEP about 5, FiO₂ titrated to the SpO₂ goal; keep plateau at or below 30 cm H₂O (typical; follow institutional protocol).
Obstructive lung disease (asthma, COPD): low rate (about 8–12/min) and a long expiratory time (I:E 1:4 or longer) so expiratory flow returns to zero. Accept hypercapnia within protocol limits. Check auto-PEEP with an end-expiratory hold (see the 2026 Marini review).
Acute brain injury: avoid hyperventilation unless it is ordered for herniation; target normocapnia per protocol. Driving pressure is associated with outcome in this group (2026 Taran secondary analysis).
Set rate for the target minute ventilation and expiratory time that allows flow to return to zero (typical; follow institutional protocol).
Confirm alarm limits before you leave the bedside.

Sizing & Positioning

Predicted body weight comes from height and sex. Actual weight does not enter into it. The formulas are in the calculations section. After every move, confirm ETT depth at the lip marking and the cuff seal.

Calculations & Derived Values

Driving pressure

Driving pressure = plateau pressure − PEEP

Static compliance

Compliance (mL/cm H₂O) = exhaled tidal volume ÷ (plateau pressure − PEEP)

Airway resistance

Resistance (cm H₂O/L/s) = (peak pressure − plateau pressure) ÷ inspiratory flow (L/s)

Predicted body weight (ARDS)

Male: 50 + 0.91 × (height in cm − 152.4) kg; Female: 45.5 + 0.91 × (height in cm − 152.4) kg

Variable	Formula	Normal or Target	Why You Care
Driving pressure	Plateau − PEEP	As low as feasible	Tracks lung stretch; trend it, not one value
Static compliance	Vt ÷ (plateau − PEEP)	Trend from baseline	Falls with ARDS, pneumothorax, distension or a stiff chest
Airway resistance	(Peak − plateau) ÷ flow	Trend from baseline	Rises with secretions, kinks, bite and bronchospasm
Predicted body weight	Height and sex formula	Set tidal volume from this	Actual weight overestimates lung size in obesity

Clinical Pearl: Plateau 28 cm H₂O with PEEP 8 cm H₂O gives a driving pressure of 20 cm H₂O. Same settings and a rising driving pressure? The lung got stiffer. The machine did not change.

Circuit Pressures & Console

Normal

Volume control: flow comes in as a square wave. Pressure spikes briefly, then holds flat on the plateau during the inspiratory pause. Expiratory flow is back at zero before the next breath.
Pressure control: pressure hits target fast and holds. Flow slows to zero before the next breath.
Pressure support: the patient's effort shows as a small negative deflection just ahead of the machine breath.

Pressure-time curve: peak 35, plateau 28 during inspiratory pause, PEEP 8 cm H₂O — **Figure 1:** Volume-control pressure-time curve (schematic). Peak pressure (35 cm H₂O) reflects resistance and stiffness. Plateau (28 cm H₂O) reflects the lung and chest alone and is read during an inspiratory hold of about 0.5–1 second. Pressure drops from the peak to the plateau as soon as the hold starts. Driving pressure is plateau minus PEEP (28 − 8 = 20 cm H₂O). Source: E3 Learning (generated diagram)

Pressure and flow tracings; expiratory flow has not returned to zero when the next breath starts — **Figure 2:** Auto-PEEP (illustrative schematic). Auto-PEEP shows as expiratory flow that has not returned to zero when the next breath starts. The airway pressure trace drops to set PEEP early in exhalation, so read auto-PEEP from the flow trace and measure it with an end-expiratory hold. Source: E3 Learning (generated diagram)

Abnormal Patterns

Asynchrony terms come from the two 2026 scoping reviews on patient-ventilator asynchrony, listed in the References.

Pattern	What You See	Cause	Fix
High peak, normal plateau	Peak rises; plateau unchanged	Airway resistance: secretions, kink, bite, bronchospasm, small tube	Suction, check circuit and bite block, treat bronchospasm per order
High peak and high plateau	Both rise together	Lower compliance: pneumothorax, mainstem intubation, distension, edema, ARDS	Check breath sounds, tube depth and chest; treat the cause per protocol
Expiratory flow not back to zero	Next breath starts before flow ends	Auto-PEEP (dynamic hyperinflation)	Lower rate or tidal volume, lengthen expiration, relieve obstruction; disconnect to deflate the lungs if unstable
Ineffective triggering	Patient effort with no machine breath	Trigger too insensitive, auto-PEEP, sedation shift	Adjust trigger, check auto-PEEP, reassess sedation
Double triggering	Two machine breaths for one patient effort	Mandatory breath lands during an effort; common in volume control	Review rate and sedation; adjust mode per protocol
Auto-triggering	Machine breath with no patient effort	Water or leak in the circuit, cardiac oscillations, trigger too sensitive	Drain water, check for leaks, adjust trigger sensitivity
Flow starvation	Patient effort meets a scooped (concave) pressure curve; patient is short of air	Set inspiratory flow too low for the patient's demand in volume modes	Raise inspiratory flow per protocol or change mode; reassess effort and sedation
Premature cycling	Machine ends the breath while the patient is still inhaling	Cycle criterion too sensitive, leak, or patient effort larger than the set breath	Adjust cycle criterion per protocol; check for leaks; reassess the patient
Delayed cycling	Patient has begun to exhale while the machine keeps delivering inspiratory flow	Cycle criterion too low, or pressure support too high	Adjust cycle criterion or pressure support per protocol; reassess sedation
Reverse triggering	A patient effort follows a passive machine breath	Strong respiratory drive or light sedation; the machine breath triggers the patient's own effort	Reassess sedation and drive per protocol; review mode and settings

Loops

Flow-volume loop, leak: the expiratory limb should be back at zero flow before the next breath. If the loop does not close, think leak.
Flow-volume loop, sawtooth: a jagged, sawtooth expiratory limb points to secretions or water in the circuit.
Flow-volume loop, obstruction: a scooped expiratory limb points to airflow obstruction, as in asthma or COPD.
Pressure-volume loop, beaking: an upper inflection on the inspiratory limb points to overdistension. Reduce tidal volume and check the plateau.

Warning: Coughing or fighting the ventilator? Do not read compliance or auto-PEEP yet. Sedate, check the patient, then measure.

Monitoring & Ongoing Care

Frequency	What to Check	Expected or Action Threshold
Hourly	Chest rise, breath sounds, SpO₂, EtCO₂ waveform, peak and plateau, exhaled volume	Plateau at or below 30 cm H₂O (ARDS); act on any new alarm
Every 4–6 h	ETT depth at the lip, cuff pressure, humidifier and water traps	Cuff 20–30 cm H₂O; re-check after any move
Every 12–24 h	Blood gas trend (PaO₂/FiO₂, PaCO₂, pH), FiO₂ and PEEP, sedation target	Wean per protocol; see the PaO₂ and CO₂ pages
Daily	Sedation interruption, weaning screen, oral care, head-of-bed position	Light sedation target (2018 PADIS guideline); pneumonia-prevention bundle

Positioning & Mobility

Keep the head of the bed raised as the bundle requires; log-roll and secure the tube when turning.
Check the circuit and tube after every position change.

Clinical Pearl: Trend the same patient on the same mode. A single reading is a snapshot. A new number is what matters.

Anticoagulation & Hematology

The ventilator does not deliver anticoagulants. Bleeding hits ventilation three ways. Suctioning and tube changes can bleed from the airway. A pneumothorax in an anticoagulated patient can bleed into the pleural space. Hemoptysis can occlude the tube. Before chest decompression or a tube change, confirm the patient's anticoagulant status.

Anticoagulants such as heparin are High-alert. Confirm the agent and dose on the order.
Plan suction and tube changes with the team when a patient is heavily anticoagulated.

Key Medications & Drug Considerations

Medication	Role Here	Typical Adult Dose / Target	Ventilator-Specific Notes
Propofol	Sedation of ventilated patients	Titrate to the sedation target; see medication page	High-alert Can drop blood pressure after a change in positive pressure; check the circuit before blaming the drug
Dexmedetomidine	Light sedation with less respiratory depression	Label (adult ICU sedation): 1 mcg/kg over 10 minutes, then 0.2–0.7 mcg/kg/hr IV infusion; many protocols omit the load	High-alert Bradycardia and hypotension; do not confuse concentrations
Rocuronium	Neuromuscular blockade for intubation or ventilator synchrony	RSI: 1 mg/kg is a common dose within the label range of 0.6–1.2 mg/kg IV. Ventilator synchrony: per ICU protocol; the label starts an infusion at 10–12 mcg/kg/min only after early recovery from the intubating dose (0.6 mg/kg). IO use per protocol (see rocuronium page)	High-alert Paralysis hides effort and dyssynchrony; the patient must be sedated first
Albuterol	Bronchospasm and obstruction-related auto-PEEP	Per order; see medication page	Treats resistance, not compliance; reassess the peak and expiratory flow after each dose
Norepinephrine	Hypotension from positive pressure, auto-PEEP or disconnect	Titrate to the MAP target; see medication page	High-alert Treat the ventilator cause at the same time

Doses vary by protocol; follow local protocols and medical direction.

Alarms & Troubleshooting

Alarm or Problem	What You See	Likely Causes	First Actions
High pressure (peak)	Peak alarm; breath stops or cycles early	Secretions, kink, bite, bronchospasm, cough, mainstem intubation, pneumothorax	1) Look and listen. 2) Suction. 3) Check the tube for kinks and bite. 4) If still high, disconnect and bag, then reassess.
Low pressure or disconnect	Low pressure, low exhaled volume	Circuit disconnect, cuff leak, tube out of position	1) Check connections and cuff. 2) If the tube is out, bag and re-intubate per airway protocol.
Low exhaled volume (leak)	Exhaled volume below set volume	Cuff underinflated, circuit or humidifier leak	Check cuff pressure (20–30 cm H₂O), circuit joins and humidifier seal
Apnea	No breath within the set time	Patient apnea, deep sedation, disconnect	Stimulate the patient, bag with oxygen, check connection
Desaturation or EtCO₂ drops	SpO₂ falls; EtCO₂ waveform flat or lower	Tube displaced, disconnect, obstruction, pneumothorax	Bag with oxygen, check tube, then work through DOPES below
High respiratory rate	Patient breathing faster than set rate	Pain, anxiety, hypoxemia, sepsis, auto-PEEP, trigger too sensitive	Assess the patient first; then check trigger, sedation and auto-PEEP
Low PEEP	Low PEEP alarm; set PEEP not reached	Leak at the cuff or circuit, disconnect, PEEP valve fault	1) Check connections and cuff. 2) Check the PEEP valve and water traps. 3) Bag if oxygenation falls.
Low minute ventilation	Low minute-volume alarm; EtCO₂ rising	Apnea, deep sedation, leak, disconnect, tube out	1) Look at the patient and the chest. 2) Check connections and the EtCO₂ waveform. 3) Bag if the patient is not breathing adequately.
Power or console failure	Alarm, blank screen	Mains loss, depleted battery, console fault	Switch to backup power; bag with oxygen; use a spare ventilator if needed

DOPES: Sudden Deterioration on a Ventilator

D, Displacement or disconnection: tube out, cuff deflated, or circuit apart. Check the EtCO₂ waveform and tube depth.
O, Obstruction: kinked, plugged or bitten tube. Secretions. A mucus plug.
P, Pneumothorax: rising pressure, falling SpO₂ and one-sided breath sounds. If blood pressure falls too, think tension (see Emergencies).
E, Equipment failure: a ventilator, humidifier or valve fault. Switch to a bag.
S, Stacked breaths: auto-PEEP is trapping air. Disconnect to let the lungs empty.

Never: Silence an alarm without finding its cause. Leave a patient disconnected without bagging. Raise PEEP or tidal volume to fix a high-pressure alarm before you know whether the cause is resistance or compliance. Reconnect a tube before EtCO₂ and breath sounds confirm placement.

Clinical Pearl: Patient first. Then the tube, the circuit and the machine, in that order. Your bag and the patient's chest tell you more than the screen ever will.

Complications & Red Flags

Complication	How You Recognize It	Immediate Action	Prevention
Barotrauma and pneumothorax	Sudden peak rise, falling SpO₂, one-sided breath sounds, hypotension if tension	Disconnect, bag, decompress per protocol	Lung-protective tidal volume and low driving pressure (ARDS Network trial; pooled ARDS driving-pressure analysis)
Hypotension from positive pressure or auto-PEEP	Blood pressure falls when PEEP rises or after disconnect	Check for auto-PEEP; disconnect briefly; vasopressor per order	Lower rate, adequate sedation, volume status per order
Ventilator-induced lung injury	Rising driving pressure or falling compliance over hours to days	Lower tidal volume and driving pressure per protocol	Lung-protective settings from the first breath
Aspiration around the cuff	Secretions above the cuff; cough; new infiltrate	Suction; check cuff pressure	Cuff 20–30 cm H₂O (usual target); oral care
Tube displacement or extubation	EtCO₂ waveform lost; sudden desaturation	Bag with oxygen; re-intubate per airway protocol	Secure the tube; check depth at the lip after every move
Ventilator-associated pneumonia	Fever, new infiltrate, purulent secretions	Cultures and antibiotics per protocol	Head-of-bed position, oral care, cuff pressure per bundle

Red Flags: Call Immediately

Blood pressure falls as peak pressure rises, with falling SpO₂ or one-sided absent breath sounds
SpO₂ keeps falling despite more FiO₂
No EtCO₂ waveform on an intubated patient
Air leak or bubbling in a chest drain after a ventilator change

Emergencies: Arrest, Power Loss & Device Failure

Sudden Hypoxemia or Hypotension on the Ventilator (DOPES)

Disconnect and bag with 100% oxygen to rescue the patient first (Paramedic/RN/CCT, per protocol). If the patient needs PEEP, use a PEEP valve on the bag.
Check the tube: depth, cuff and EtCO₂ waveform.
Listen to both chests. One-sided absent breath sounds with rising pressure and hypotension point to tension pneumothorax: decompress per protocol.
Suction the tube if it is obstructed.
If the tube is out and the patient is unstable, re-intubate per the airway protocol.
Call for help and check the console only after the patient is oxygenating.

Cardiac Arrest on the Ventilator

Start CPR per AHA adult and ACLS protocol.
With an advanced airway in place, give 1 breath every 6 seconds (10 breaths/min) with continuous chest compressions (2025 AHA Guidelines for CPR and ECC, Part 9; Class 2b, LOE C-LD).
Confirm the tube with waveform capnography (2025 AHA Guidelines for CPR and ECC, Part 9; Class 1, LOE C-LD).
If the ventilator is not delivering reliable breaths, or auto-PEEP is suspected (breath stacking), disconnect and bag with 100% oxygen at 1 breath every 6 seconds without pausing compressions.
Follow reversible causes, including the DOPES list above.

Power or Ventilator Failure

Switch to battery or backup power on the console.
If there is no backup, bag with oxygen and watch chest rise.
Check the tube and circuit for disconnect or kink.
Use a spare ventilator with the same tube if one is available.
Keep EtCO₂ monitoring connected throughout.

Circuit Separation or Tube Out

Bag immediately with oxygen.
Do not reconnect until the tube position is confirmed by EtCO₂ and breath sounds.
Suction and check the cuff.
Re-intubate per protocol if the tube is out; see the intubation guide.

Weaning & Discontinuation

Readiness Criteria

The cause of respiratory failure is treated or improving.
Oxygenation adequate on low FiO₂ and PEEP per protocol.
Stable on no or low-dose vasopressor support.
Able to protect the airway and clear secretions.

Weaning Steps

Run a ventilator liberation protocol, with daily sedation interruption and a spontaneous breathing trial (ATS/ACCP 2017 guideline).
Reduce pressure support or move to a trial per protocol; watch for patient-ventilator mismatch.
Before extubation in patients at higher risk of post-extubation stridor, consider a cuff leak test (conditional recommendation, ATS/ACCP 2017 guideline).

Failure Criteria: Step Back Up

Rising work of breathing, tachypnea, accessory muscle use or paradoxical breathing.
Falling SpO₂ or rising PaCO₂ on the trial.
Agitation or new dyssynchrony that sedation does not fix.

Removal & Post-Removal Care

Suction before extubation; watch for stridor and airway edema after removal.
Keep humidified oxygen available and the patient upright unless the order says otherwise.

Protocol Varies: Every unit sets its own thresholds and trial lengths. Run the local protocol.

Transport Considerations

Before You Move

Check battery run time and the backup power source.
Check oxygen cylinder contents and duration at the planned flow.
Secure the tube, circuit and all lines; carry a spare bag-valve.
Confirm alarm limits and EtCO₂ monitoring.
Brief the receiving team on settings, sedation and recent alarms.

If You Are Not the Device Specialist

Watch SpO₂, EtCO₂, blood pressure and chest rise.
Do not change the mode or settings without an order.
If the screen goes blank, bag the patient with oxygen.
Do not silence alarms you do not understand; call for help.

During Transport

Recheck tube depth and cuff pressure after every move and after any change in altitude.
Keep connections short and secured; avoid tugging the circuit.

Air Medical & Altitude

Gas in the cuff and the circuit expands as ambient pressure falls with altitude (Boyle's law). That is why cuff pressure rises on ascent and falls on descent. Every altitude change means a fresh manometer check of the cuff. Whether the transport ventilator compensates for altitude depends on the device. Some services inflate the cuff with saline instead. Follow local protocol.

Handoff

Mode and working settings, including PEEP and FiO₂.
Last plateau pressure, last blood gas and recent alarms with the fix.
Sedation, paralysis and anticoagulation status.
Tube size, depth, cuff pressure and any leak.

Transport Pearl: Put the working settings on paper, with the alarm you fixed beside them. The next team needs both.

Special Populations

Pediatric & Neonatal

The adult 6 mL/kg target and the adult predicted-body-weight formulas do not apply to children. For pediatric ARDS, the PALICC-2 executive summary suggests tidal volume 6–8 mL/kg predicted body weight. Go below 6 mL/kg only as needed to keep plateau pressure at or below 28 cm H₂O and driving pressure at or below 15 cm H₂O. These are conditional recommendations. Below 4 mL/kg, go only with caution. Tube choice and the rest of pediatric ventilation run on the institutional pediatric protocol. Pediatric weight-based dosing is on the weight-based dosing page. See also pediatric airway.

Other

Obesity: calculate tidal volume from predicted body weight, not actual weight.
Pregnancy: follow the obstetric critical care protocol. Don't apply adult targets without it. Left uterine displacement relieves aortocaval compression from about 20 weeks. Normal pregnancy PaCO₂ runs about 30 mmHg. Avoid hypercapnia. Avoid over-correcting it too, because a low PaCO₂ can reduce uterine blood flow. The obstetric team sets maternal oxygenation targets. Avoid maternal hypoxemia, which harms the fetus.

Note: Neonatal ventilation runs on neonatal targets and equipment. This page does not cover it.

Bedside Pearls & Teaching Script

Systematic Walk-Through

Is the patient breathing and oxygenating? Look and listen first.
Check the tube position and the EtCO₂ waveform.
Read the pressure waveform: peak against plateau.
Read the expiratory flow for auto-PEEP.
Check the circuit, humidifier and water traps.
Check the console settings and alarm limits.
Decide: fix the cause, bag, or call for help.

Pearls

A rising peak with a normal plateau points to the airway. A rising plateau points to the chest and the lung.
Bag first when the patient gets worse, not when the alarm gets loud.
Auto-PEEP hides on most screens. Look at expiratory flow. Measure it with an end-expiratory hold.
Paralysis hides the patient's effort. Re-check the waveform after rocuronium.

References

Acute Respiratory Distress Syndrome Network; Brower, R. G., Matthay, M. A., Morris, A., Schoenfeld, D., Thompson, B. T., & Wheeler, A. (2000). Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome (landmark trial). New England Journal of Medicine, 342(18), 1301–1308. https://doi.org/10.1056/NEJM200005043421801
Amato, M. B., Meade, M. O., Slutsky, A. S., Brochard, L., Costa, E. L., Schoenfeld, D. A., Stewart, T. E., Briel, M., Talmor, D., Mercat, A., Richard, J.-C., Carvalho, C. R., & Brower, R. G. (2015). Driving pressure and survival in the acute respiratory distress syndrome. New England Journal of Medicine, 372(8), 747–755. https://doi.org/10.1056/NEJMsa1410639
Fan, E., Del Sorbo, L., Goligher, E. C., et al. (2017). An official American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine clinical practice guideline: Mechanical ventilation in adult patients with acute respiratory distress syndrome. American Journal of Respiratory and Critical Care Medicine, 195(9), 1253–1263. https://doi.org/10.1164/rccm.201703-0548ST
Leigh-Smith, S., & Harris, T. (2005). Tension pneumothorax: time for a re-think? Emergency Medicine Journal, 22(1), 8–16. https://pubmed.ncbi.nlm.nih.gov/15611534/
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