Mechanical ventilation troubleshooting (asthma, ARDS, COPD)MANAGEMENT

RESPIRATORY PRESENTATIONS · 12 SECTIONS

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675 items

☷ Legend

01Approach to the Critical Patient/attcp103

Immediate priorities in the crashing ventilated patient

›Sudden deterioration threats

›Hypoxemia

›SpO2 falling despite unchanged FiO2 and settings

›High pressure alarm firing concurrently

›Hypotension immediately after intubation or a ventilator change

›Most common mechanism is auto-PEEP from dynamic hyperinflation

›Occurs within minutes of positive pressure initiation

›Cardiac arrest with pulseless electrical activity

›Tension pneumothorax or severe auto-PEEP as reversible causes

›Do not attribute to primary cardiac arrest without a ventilator-cause screen

›If any of the above, disconnect the circuit before further workup

›Disconnection is diagnostic and therapeutic simultaneously

›Hand-ventilate with a bag-valve device on 100% oxygen

DOPES and DOTTS structured approach

›DOPES: causes of acute deterioration on the ventilator

›Displacement of the endotracheal tube

›Mainstem migration, most often right mainstem

›Inadvertent extubation

›Obstruction of the tube or airway

›Secretions, mucus plugging, or blood clot

›Kinking or patient biting the tube

›Pneumothorax, usually tension physiology in a ventilated patient

›Positive pressure converts a simple pneumothorax to tension rapidly

›Sudden unilateral absence of breath sounds with hypotension

›Equipment failure

›Ventilator malfunction or circuit disconnection

›Oxygen supply failure or exhausted cylinder

›Stacked breaths

›Breath stacking and dynamic hyperinflation with auto-PEEP

›Most likely in obstructive disease with high minute ventilation demand

›DOTTS: the corresponding action sequence

›Disconnect the patient from the ventilator circuit

›Allow full passive exhalation for 15 to 60 seconds

›Gentle bilateral chest wall compression can accelerate exhalation

›One hundred percent oxygen by bag-valve device

›Hand-ventilate at a slow rate, 6 to 8 breaths per minute

›Assess compliance to bagging by feel

›Tube position and patency check

›Auscultate for bilateral, symmetric breath sounds

›Pass a suction catheter down the tube

›Catheter fails to pass to expected depth confirms obstruction or kinking

›Catheter passes freely and returns secretions suggests plugging relieved

›Tweak the ventilator

›Reduce respiratory rate and minute ventilation

›Increase inspiratory flow rate and expiratory time

›Sonography

›Bedside ultrasound for pneumothorax, mainstem intubation, and effusion

›Needle decompression or finger thoracostomy if tension physiology confirmed or strongly suspected with hemodynamic collapse

Peak versus plateau pressure discriminator

›Plateau pressure measurement technique

›End-inspiratory hold maneuver

›Apply an inspiratory pause of 0.5 to 2 seconds on volume-control ventilation

›Read the pressure once inspiratory flow reaches zero

›Requires a passive patient for an accurate reading

›Spontaneous effort during the hold invalidates the measurement

›Brief additional sedation may be needed solely to obtain the measurement

›Interpretation of the peak-plateau relationship

›High peak pressure with normal plateau pressure

›Indicates a resistance problem in the airway or circuit

›Peak-plateau gradient greater than approximately 15 cm H2O

›Differential: tube obstruction, bronchospasm, secretions, biting, kinked tubing

›High peak pressure with high plateau pressure

›Indicates a compliance problem in the lung, chest wall, or thorax

›Plateau pressure elevated together with peak pressure

›Differential: pneumothorax, mainstem intubation, auto-PEEP, abdominal distension, pulmonary edema

›Plateau pressure target

›Plateau pressure <= 30 cm H2O

›Driving pressure, plateau pressure minus PEEP, target < 15 cm H2O

Disconnect and decompress maneuver

›Sudden hypotension or arrest after intubation in obstructive disease

›This is the life-saving action and takes priority over any other workup

›Disconnect the endotracheal tube from the ventilator circuit immediately

›Apply firm manual pressure to the chest wall to hasten passive exhalation

›Reconnection strategy

›Reconnect at a lower respiratory rate and lower minute ventilation

›Reassess blood pressure within one minute of reconnection

›If hypotension recurs on reconnection

›Repeat the disconnect-and-decompress cycle

›Pursue concurrent volume loading and consider a pneumothorax screen

Iatrogenic harms audit

›Intubation

›Positive pressure ventilation precipitates auto-PEEP and obstructive shock in severe airflow obstruction

›Loss of the patient's own respiratory drive removes the compensatory tachypnea that was maintaining minute ventilation

›Sedation

›Deep sedation is usually required to prevent dyssynchrony but propofol bolus dosing worsens hypotension in preload-dependent auto-PEEP physiology

›Ketamine is preferred in obstructive disease for its bronchodilatory and hemodynamically neutral profile

›Fluid loading

›Indicated pre-intubation in obstructive disease to buffer the hypotension of positive pressure initiation

›Contraindicated as a routine strategy in ARDS once shock has resolved; a conservative fluid strategy improves ventilator-free days

›Oxygen

›High FiO2 does not correct an obstruction or compliance problem and delays recognition of the true cause

›Hyperoxia is avoided; target SpO2 88% to 95% once the acute crisis is controlled

›Vasopressors

›Reasonable temporizing measure for auto-PEEP-induced obstructive shock while decompression is performed

›Not a substitute for decompression; pressors alone do not correct dynamic hyperinflation

›Mechanical circulatory support including intra-aortic balloon pump

›Not indicated as a primary strategy for auto-PEEP-induced obstructive shock

›The physiology is impaired venous return from elevated intrathoracic pressure, not a primary pump failure, so circulatory support does not address the mechanism

›Anticoagulation

›Standard VTE prophylaxis dosing applies unless a procedure such as chest tube placement is imminent

›Hold before needle decompression or thoracostomy when time allows

›Fibrinolysis

›Not indicated for the primary conditions in this topic

›Reserve for confirmed massive pulmonary embolism only; inappropriate use adds bleeding risk without benefit in obstructive or ARDS physiology

›Analgesia

›Opioid bolus dosing can precipitate hypotension in preload-dependent auto-PEEP physiology

›Required as part of an analgosedation strategy but titrate in small increments during the acute crisis

02History/hx25

Pre-crisis ventilator and clinical context

›Indication for mechanical ventilation

›Underlying diagnosis driving ventilator support

›Status asthmaticus, COPD exacerbation, or ARDS

›Time since intubation

›Ventilator mode and settings prior to deterioration

›Mode, rate, tidal volume, PEEP, FiO2

›Any setting change in the preceding minutes

›Sedation and paralysis status

›Current sedation depth and agent

›Recent bolus or infusion rate change

›Neuromuscular blockade in use

Timeline and trigger of deterioration

›Onset characteristics

›Abrupt versus gradual desaturation or pressure rise

›Abrupt onset favors pneumothorax, mainstem migration, or disconnection

›Gradual onset favors secretions, worsening bronchospasm, or evolving edema

›Temporal relationship to an intervention

›Coincides with suctioning, repositioning, or a ventilator change

›Coincides with a sedation or paralytic bolus or infusion adjustment

›Nursing and respiratory therapy report

›Recent alarm history

›Which alarm fired first

›Trend of peak and plateau pressures over the preceding hour

›Recent suctioning findings

›Volume and character of secretions

›Ease of catheter passage

03Physical Exam/exam38

Circuit and airway exam

›Circuit inspection

›Tubing patency and connections

›Visible kinking or water in the circuit

›Circuit fully connected from ventilator to tube

›Endotracheal tube position

›Depth at the teeth compared with documented baseline depth

›Cuff leak audible at the mouth

›Suction catheter pass

›Resistance to passage

›Catheter meets resistance before expected depth

›Catheter passes freely

›Secretion characteristics

›Thick or bloody secretions

›Volume returned

Chest and hemodynamic exam

›Auscultation

›Symmetry of breath sounds

›Unilateral absence suggests mainstem intubation or pneumothorax

›Bilateral wheeze suggests bronchospasm

›Chest wall movement

›Asymmetric expansion

›Subcutaneous emphysema or crepitus

›Hemodynamic assessment

›Blood pressure trend

›Hypotension coincident with the ventilator change

›Pulse pressure narrowing

›Neck and jugular exam

04Differential Diagnosis/ddx61

High peak pressure with normal plateau pressure — resistance problems

›Airway and circuit causes

›Bronchospasm

›Diffuse expiratory wheeze

›Responds to bronchodilator therapy

›Secretions or mucus plugging

›Resistance to suction catheter passage

›Improves after suctioning

›Kinked or bitten tube

›Bite block malposition

›Visible external kink

›Endotracheal tube too small or partially obstructed by a clot

›Higher resistance at higher flow rates

›Catheter passage difficult but possible

High peak pressure with high plateau pressure — compliance problems

›Thoracic and lung causes

›Tension pneumothorax

›ICD-10 J93.0

›Unilateral absent breath sounds with hypotension

›Mainstem intubation

›Unilateral breath sounds, usually right-sided

›Tube depth deeper than documented baseline

›Auto-PEEP and dynamic hyperinflation

›Confirmed by end-expiratory hold maneuver

›Most common in obstructive disease with inadequate expiratory time

›Abdominal distension

›Elevated intra-abdominal pressure splinting the diaphragm

›Gastric distension from bag-mask ventilation before intubation

05Laboratory Tests/lt28

Gas exchange and acid-base monitoring

›Arterial blood gas

›Oxygenation trend

›PaO2/FiO2 trend across the crisis

›Correlation with SpO2 to establish a reliable trending proxy

›Ventilation and acid-base trend

›PaCO2 trajectory relative to minute ventilation delivered

›pH relative to the permissive hypercapnia target

›Lab-interpretation trap

›Rising PaCO2 with unchanged delivered minute ventilation suggests worsening obstruction or auto-PEEP rather than a primary metabolic process

›Widening gap between PaCO2 and end-tidal CO2 suggests increased dead space or pulmonary embolism rather than a ventilator setting problem

›End-tidal capnography

›Waveform shape

›Shark-fin morphology, a rising expiratory upslope, indicates bronchospasm

›Loss of waveform suggests disconnection, esophageal placement, or cardiac arrest

Electrolyte and metabolic monitoring

›Potassium

›Hypokalemia from beta-agonist therapy

›Intracellular potassium shift from beta-2 stimulation

›ECG correlation: flattened T waves, U waves, QT prolongation, risk of torsades de pointes

›Hyperkalemia risk with succinylcholine

›Risk elevated with prolonged immobilization, burns, or preexisting neuromuscular disease

›ECG correlation: peaked T waves and QRS widening before use if hyperkalemia is already suspected

›Renal and metabolic panel

›Renal function for sedative and paralytic dose adjustment

›Cisatracurium is organ-independent and preferred with renal impairment

›Rocuronium clearance prolonged in renal and hepatic failure

›Glucose

06Diagnostic Tests/dt56

Scoring Systems

›Sedation and paralysis scoring

›Richmond Agitation-Sedation Scale

›Target individualized to the ventilation strategy in use

›Deeper targets acceptable when permissive hypercapnia or neuromuscular blockade is in use

›Train-of-four monitoring during neuromuscular blockade

›Peripheral nerve stimulator at the ulnar or facial nerve

›Target 1 to 2 twitches of 4 to avoid excessive blockade

›Berlin definition severity strata for ARDS, applied to this population

›Mild PaO2/FiO2 200 to 300 mmHg

›Moderate PaO2/FiO2 100 to 200 mmHg

›Severe PaO2/FiO2 <= 100 mmHg

MRI

›MRI role in ventilator troubleshooting

›Acute utility very limited

›Not indicated during an acute ventilator crisis

›Incompatible with continuous monitoring needs of an unstable patient

›Contraindications

›Hemodynamic instability

›Non-compatible implants or monitoring equipment

›CT chest indications

›Diagnostic uncertainty after bedside workup

›Suspected occult pneumothorax not confirmed on plain film or ultrasound

›Suspected structural airway abnormality

›Not indicated during hemodynamic instability

›Bedside ultrasound and plain film take priority

›CT only after the patient is stabilized

07Disposition/dispo25

ICU and transfer criteria

›ICU-level care

›All patients requiring invasive mechanical ventilation

›No floor-level or stepdown management of an unstable ventilated patient

›Continuous hemodynamic and respiratory monitoring

›Refractory hypoxemia or hemodynamic instability

›ECMO center evaluation for refractory ARDS

›Refractory obstructive shock despite decompression and pressors

›Transfer criteria for non-tertiary emergency departments

›Indications for transfer

›No on-site intensivist or ICU bed capacity

›Need for prone positioning expertise or ECMO not available locally

›Stabilization before transport

›Definitive airway secured and tube position confirmed

›Accepting ICU bed and receiving physician confirmed before transport

Weaning and step-down readiness

›Spontaneous breathing trial readiness

›Objective criteria

›FiO2 <= 0.5

›PEEP <= 8 cm H2O

›Clinical criteria

›Hemodynamically stable without escalating vasopressor requirement

›Adequate mental status to protect the airway after extubation

›COPD-specific weaning considerations

›Higher extubation failure risk than other populations

›Plan for immediate noninvasive ventilation after extubation in high-risk patients

›Optimize bronchodilator and corticosteroid therapy before the trial

08Treatment/t215

Sudden deterioration checklist

›Ordered action sequence

›Disconnect the patient from the ventilator and hand-ventilate with 100% oxygen

›Perform this step before further diagnostic workup in any acute crisis

›Assess ease of bagging by feel

›If bagging is easy and the patient improves

›Suspect a ventilator or circuit problem, or auto-PEEP relieved by disconnection

›Inspect the ventilator and circuit before reconnecting

›If bagging is difficult

›Suspect a tube or patient problem

›Pass a suction catheter to assess tube patency

›Auscultate for symmetric breath sounds

›Unilateral absence directs to mainstem intubation or pneumothorax

›Confirm findings with bedside ultrasound

›Treat the identified cause

›Withdraw the tube for mainstem intubation

›Needle decompression or thoracostomy for confirmed or strongly suspected tension pneumothorax

›If no cause is found and the patient remains unstable

›Reassess sedation depth and consider neuromuscular blockade for severe dyssynchrony

›Reassess volume status and consider a fluid bolus for preload-dependent hypotension

Alarm interpretation and response

›High pressure alarm

›Common causes

›Secretions, bronchospasm, biting, mainstem intubation, pneumothorax, breath stacking

›Immediate response

›Determine peak versus plateau pattern

›Follow the resistance versus compliance differential accordingly

›Low pressure or low minute ventilation alarm

›Common causes

›Circuit disconnection, cuff leak, large air leak

›Immediate response

›Inspect the full circuit from ventilator to tube

›Check cuff pressure and reinflate or replace as needed

›Apnea alarm

›Common causes

›Over-sedation, disconnection, respiratory arrest

›Immediate response

›Confirm circuit integrity first

›Reassess sedation depth and consider dose reduction if over-sedated

›High respiratory rate alarm

›Common causes

›Pain, anxiety, acidosis, dyssynchrony, worsening gas exchange

›Immediate response

›Reassess for a settings mismatch before escalating sedation

›Check for a new metabolic acidosis driving compensatory tachypnea

Patient-ventilator dyssynchrony management

›Settings-first approach

›The initial response to most dyssynchrony is a ventilator settings change, not sedation

›Increase inspiratory flow rate for flow starvation

›Shorten inspiratory time and prolong expiratory time for obstructive disease with premature cycling

›When sedation is the correct response

›Settings optimization has failed to resolve dyssynchrony

›Deep sedation is independently indicated, such as during a permissive hypercapnia protocol or neuromuscular blockade

›Sedative agents and dosing

›Propofol

›5 to 50 mcg/kg/min IV continuous infusion

›Bolus dosing 0.5 to 1 mg/kg IV; omit or minimize bolus in hypotension-prone patients

›Monitoring cadence: reassess sedation depth every 1 to 2 hours and after every rate change

›Midazolam

›0.02 to 0.1 mg/kg/h IV continuous infusion

›Alternative when propofol infusion syndrome risk is a concern

›Fentanyl

›25 to 100 mcg IV bolus

›0.7 to 10 mcg/kg/h IV continuous infusion

›Titrate in small increments to avoid a hypotensive bolus effect

›Ketamine

›0.5 to 2 mg/kg/h IV continuous infusion for refractory bronchospasm with sedation need

›Preferred in obstructive disease for bronchodilatory and hemodynamically neutral properties

›Neuromuscular blockade

›Cisatracurium

›Bolus 0.1 to 0.2 mg/kg IV, or 1 to 3 mcg/kg/min IV continuous infusion

›Limit continuous infusion duration to <= 48 hours

›Monitoring cadence: train-of-four assessment every 2 to 4 hours, target 1 to 2 twitches of 4

›Indication specifics

›Severe dyssynchrony refractory to settings change and adequate sedation

›Deep sedation is a prerequisite before initiating neuromuscular blockade

Obstructive disease ventilator strategy (asthma and COPD)

›Core settings

›Low respiratory rate

›10 to 12 breaths per minute

›Lower rate directly increases available expiratory time

›Tidal volume

›6 to 8 mL/kg ideal body weight

›Inspiratory flow and expiratory time

›High inspiratory flow rate, 60 to 100 L/min, to shorten inspiratory time

›Prolonged expiratory time, I:E ratio 1:4 or greater

›Permissive hypercapnia

›Targets

›Accept PaCO2 up to 70 to 80 mmHg

›Target pH > 7.20 rather than a normal PaCO2

›Threshold exceptions

›Avoid permissive hypercapnia with raised intracranial pressure

›Avoid or minimize with severe pulmonary hypertension or right heart failure

›Use caution in chronic CO2 retainers already near their baseline compensation limit

Auto-PEEP and breath-stacking management

›Mechanism

›Incomplete exhalation before the next breath begins causes progressive air trapping

›Increased end-expiratory lung volume and intrathoracic pressure

›Impaired venous return and obstructive shock, up to pulseless electrical activity arrest

›Detection

›End-expiratory hold maneuver on the ventilator

›Measures total PEEP; auto-PEEP equals total PEEP minus set PEEP

›Flow-time waveform inspection

›Expiratory flow not returning to zero before the next breath

›Management

›Reduce minute ventilation

›Lower respiratory rate and tidal volume

›Prolong expiratory time

›Disconnect and decompress for hemodynamic compromise

›See the disconnect and decompress maneuver in Approach to the Critical Patient

›"Therapy is not working" node

›Persistent auto-PEEP despite rate reduction and adequate bronchodilator therapy

›Reassess for a fixed mechanical obstruction, such as a mucus plug or a kinked tube, rather than assuming physiologic obstruction alone

Bronchodilator and adjunct therapy during ventilation

›Inhaled bronchodilators

›Albuterol

›2.5 to 5 mg nebulized in-line every 20 minutes for 3 doses, then every 1 to 4 hours as needed

›Continuous nebulization 10 to 15 mg per hour for severe, refractory bronchospasm

›Ipratropium bromide

›0.5 mg nebulized in-line every 20 minutes for 3 doses

›Magnesium sulfate

›Adult dosing

›2 g IV over 20 minutes

›Monitoring

›Blood pressure monitoring during infusion for hypotension

›Renal function assessment before administration

›"Therapy is not working" node

›Persistent bronchospasm and rising pressures despite bronchodilators and magnesium

›Reassess for an alternative diagnosis: mucus plugging, mainstem migration, pneumothorax

›Escalate to ketamine infusion, heliox, or inhaled anesthetics before assuming maximal medical therapy has failed

ARDS lung-protective ventilation and PEEP strategy

›Tidal volume by predicted body weight

›Predicted body weight formula

›Male: 50 + 2.3 x (height in inches - 60) kg

›Female: 45.5 + 2.3 x (height in inches - 60) kg

›Target tidal volume

›6 mL/kg predicted body weight, acceptable range 4 to 8 mL/kg

›Strong recommendation from the ATS/ESICM/SCCM 2017 mechanical ventilation guideline

›Pressure limits

›Plateau pressure <= 30 cm H2O

›Driving pressure < 15 cm H2O

›Permissive hypercapnia in ARDS

›Targets

›Maintain pH > 7.20

›Prioritize low tidal volume over a normal PaCO2

›Threshold exceptions

›Avoid with raised intracranial pressure

›Avoid with severe pulmonary hypertension

›PEEP strategy

›Minimum PEEP >= 5 cm H2O

›Higher PEEP for moderate-to-severe ARDS, titrated against oxygenation and driving pressure response

›Recruitment maneuvers

›Prolonged recruitment maneuvers recommended against

›Strong recommendation from the ATS/ESICM/SCCM 2017 guideline

›Corticosteroids

›Moderate-to-severe ARDS within 14 days of onset

›Dexamethasone 20 mg IV daily for 5 days, then 10 mg IV daily for 5 days

›Avoid initiation beyond 14 days, as later initiation may worsen outcomes

›Monitoring

›Glycemic control

›Surveillance for secondary infection

Prone positioning

›Protocol

›Indication

›Moderate-to-severe ARDS, PaO2/FiO2 < 150 mmHg

›Duration

›12 to 16 hours per day, repeated daily until sustained improvement

›Combined strategy

›Low tidal volume ventilation together with prone positioning produces the greatest mortality reduction

›Safety during proning

›Airway and line security

›Confirm endotracheal tube position before and after turning

›Secure all vascular access before the turn

›Pressure injury surveillance

›Facial and dependent-area skin checks each shift

›"Therapy is not working" node

›No improvement in oxygenation after an adequate prone trial

›Reassess ECMO candidacy

›Reassess for a missed alternative diagnosis such as a large effusion or occult pneumothorax

COPD-specific ventilation and weaning

›Distinguishing COPD from asthma in ventilation terms

›Baseline hypercapnia and chronic respiratory acidosis with metabolic compensation

›Permissive hypercapnia targets are individualized to the patient's known baseline PaCO2, not a fixed number

›Lower likelihood of full reversibility with bronchodilators alone

›Fixed airflow obstruction component in addition to any reversible bronchospasm

›Higher baseline risk of dynamic hyperinflation even at rest

›Auto-PEEP present at baseline in advanced disease

›Weaning strategy

›Extubation to noninvasive ventilation

›Reduces reintubation risk in COPD patients extubated after acute respiratory failure

›Bronchodilator and corticosteroid optimization before the weaning trial

Rescue and refractory therapies

›Refractory obstructive bronchospasm

›Heliox

›70:30 or 80:20 helium to oxygen mixture

›Not suitable when FiO2 requirement > 0.4

›Inhaled anesthetics

›Sevoflurane or isoflurane, last-line therapy for intubated patients with refractory bronchospasm

›Requires anesthesiology involvement

›Refractory ARDS hypoxemia

›Inhaled pulmonary vasodilators

›Inhaled nitric oxide, transient oxygenation improvement without proven mortality benefit

›VV-ECMO

›Selected severe refractory ARDS after conventional therapy has failed

›Early referral before multi-organ failure develops

›Vasopressor support during ventilator troubleshooting

›Norepinephrine

›0.01 to 0.5 mcg/kg/min IV continuous infusion

›Monitoring cadence: reassess mean arterial pressure every 5 minutes during titration, target MAP >= 65 mmHg

Rapid sequence intubation for the deteriorating obstructive patient

›Pre-intubation optimization

›Volume loading

›500 to 1000 mL crystalloid bolus in adults before induction, to buffer positive-pressure-induced hypotension

›Preoxygenation

›Target SpO2 as high as achievable before induction; avoid delaying for a marginal further gain

›Induction and paralytic agents

›Ketamine

›1 to 2 mg/kg IV, preferred for bronchodilatory properties

›Succinylcholine

›1 to 1.5 mg/kg IV

›Avoid or use caution with known hyperkalemia risk factors; obtain an ECG or point-of-care potassium first when time allows

›Rocuronium

›1 to 1.2 mg/kg IV, alternative when succinylcholine is contraindicated

›Post-intubation ventilator strategy

›Initiate at a low respiratory rate, 10 to 12 breaths per minute, from the first delivered breath

›Anticipate and prepare for the disconnect and decompress maneuver before the first hypotensive episode occurs

09Special Populations/sp44

Pregnancy

›Ventilated obstetric patient

›Physiologic vulnerability

›Reduced functional residual capacity from the gravid uterus increases desaturation speed during any disconnection

›Increased oxygen consumption

›Oxygenation goal exception

›Maintain maternal SpO2 >= 95% when feasible, higher than the general 88% to 95% target, for fetal oxygenation

›Positioning

›Left lateral tilt to relieve aortocaval compression during any troubleshooting maneuver

›Medication safety

›Albuterol and ipratropium are safe in all trimesters

›Magnesium sulfate is safe and also used for tocolysis

›Ketamine is an acceptable induction agent in pregnancy

›Fetal monitoring

›Continuous fetal heart rate monitoring when viable gestation

›Obstetrics consultation for any ventilator crisis

Geriatric

›Older adult considerations

›Reduced physiologic reserve

›Less tolerance for transient hypoxemia during troubleshooting maneuvers

›Higher mortality for a given severity of ARDS or obstructive crisis

›Comorbidity interactions

›Coexisting heart failure complicates the auto-PEEP versus cardiogenic edema distinction

›Beta-blocker use for cardiac disease may blunt the tachycardic response used to gauge bronchodilator effect

›Medication dose adjustment

›Renal function assessment before magnesium sulfate and before renally cleared paralytics

›Lower sedative bolus doses to reduce hypotension risk

›Goals of care

10Background/b30

Epidemiology

›Obstructive disease ventilator crises

›Intubation for status asthmaticus occurs in a small minority of ED presentations, but carries a disproportionate mortality risk

›25,000 to 50,000 ICU admissions per year in the United States for life-threatening asthma

›Post-intubation hypotension occurs in a substantial proportion of obstructive patients placed on positive pressure ventilation

›ARDS ventilator crises

›ARDS affects approximately 10% of ICU admissions and approximately 24% of mechanically ventilated patients

›Approximately 40% of ARDS is unrecognized at diagnosis, and only about 31% of recognized cases initially receive lung-protective ventilation

›In-hospital mortality ranges from approximately 27% in mild disease to approximately 45% in severe disease

Pathophysiology

›Obstructive mechanism of ventilator crisis

›Dynamic hyperinflation

›Incomplete exhalation leads to progressive air trapping and rising intrathoracic pressure

›Intrinsic PEEP impairs venous return and can precipitate obstructive shock

›Increased inspiratory work

›Inspiratory muscles, or the ventilator, must first overcome intrinsic PEEP to initiate flow

›ARDS mechanism of ventilator crisis

›Diffuse alveolar damage

›Increased alveolar-capillary permeability and protein-rich noncardiogenic edema

›Heterogeneous lung involvement, with normally compliant and severely diseased regions coexisting

›Ventilator-induced lung injury

›Volutrauma from overdistension of compliant lung units

›Atelectrauma from cyclic opening and closing of unstable alveoli

›Barotrauma from excessive plateau pressure

Therapeutic Considerations

›Shared principles across obstructive disease and ARDS

›Minute ventilation reduction is protective in both settings, though for different mechanical reasons

›In obstructive disease it allows adequate exhalation time

11Patient Discharge Instructions/pdi21

copy discharge instructions

›Recovery after a ventilator-supported critical illness

›Recovery from a severe breathing crisis is gradual over weeks to months

›Pulmonary rehabilitation as recommended by your care team

›Continue all prescribed inhalers and medications until reviewed at follow-up

›Expected effects after critical illness

›Reduced exercise tolerance and muscle weakness

›Memory and concentration difficulty

›Persistent breathlessness improving gradually over time

›Warning signs requiring immediate return to the emergency department

›Worsening shortness of breath or inability to complete a sentence

›Blue lips or fingernails

›New fever or chills

›Chest pain

›Confusion or sudden functional decline

›Follow-up

›Primary care and pulmonology follow-up after discharge

›Pulmonary function testing at 3 to 6 months for ARDS survivors

›Review and update your written asthma or COPD action plan at follow-up

›Prevention

›Take your controller inhaler every day even when feeling well

›Identify and avoid your personal triggers, including smoke, allergens, and cold air

12References/r29

Guidelines and key sources

›Primary guidelines

›ATS/ESICM/SCCM clinical practice guideline on mechanical ventilation in adult ARDS

›Fan E et al. American Journal of Respiratory and Critical Care Medicine. 2017

›GINA Global Strategy for Asthma Management and Prevention

›Global Initiative for Asthma. 2025

›GOLD Global Strategy for the Diagnosis, Management, and Prevention of COPD

›Global Initiative for Chronic Obstructive Lung Disease. 2025

›New Global Definition of ARDS

›Matthay MA et al. American Journal of Respiratory and Critical Care Medicine. 2024

›Landmark trials

›Ventilation with lower tidal volumes for acute lung injury and ARDS

›ARDS Network. New England Journal of Medicine. 2000

›Prone positioning in severe ARDS, the PROSEVA trial

›Guerin C et al. New England Journal of Medicine. 2013

›Neuromuscular blockade in early ARDS, the ACURASYS trial

›Papazian L et al. New England Journal of Medicine. 2010

›Reevaluation of systemic early neuromuscular blockade, the ROSE trial

›National Heart, Lung, and Blood Institute PETAL Network. New England Journal of Medicine. 2019

›Ventilator troubleshooting reviews

›Managing initial mechanical ventilation in the emergency department

›Weingart SD. Annals of Emergency Medicine. 2016

›Principles and Practice of Mechanical Ventilation

›Tobin MJ, editor. McGraw-Hill textbook reference

›Coding standards

›ICD-10 J96.01 acute respiratory failure with hypoxia

›ICD-10 J93.0 spontaneous tension pneumothorax

›ICD-10 J80 acute respiratory distress syndrome

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed September 13, 2026

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