1. Home Mechanical Ventilation
Cori Daines, MD
Pediatric Pulmonary Medicine

2. Outline Indications Patients Interfaces Ventilators
Modes of ventilation
Home considerations
Complications
Outcomes

3. Goals Extend the duration of life Enhance the quality of life
Reduce morbidity
Improve physiologic function
Achieve normal growth and development
Reduce overall health care costs

4. Indications Disorders of the respiratory pump
Neuromuscular diseases, chest wall diseases, spinal cord injury
Obstructive diseases of the airway
Craniofacial abnormalities, hypotonia, obesity
Parenchymal lung disease
BPD, cystic fibrosis
Disorders of control of respiration
Congenital central hypoventilation syndrome

5. Indications Inability to wean from mechanical ventilation
After and acute illness
After prolonged ventilation for a chronic disease
Progressive chronic respiratory failure
Sleep disturbance
Central or obstructive, apnea or hypopnea

6. Indications/Symptoms
Shortness of breath
Especially on exertion or lying down
Morning headache and insomnia
Fatigue and lethargy
Increased respiratory rate
Restlessness and anxiety

7. Indications/Criteria
Forced vital capacity < 50% predicted
Maximal Inspiratory Pressure < 60
ABG pCO2 > 45
Moderate to severe sleep apnea

8. Patients Cardiopulmonary stability
Positive trend in weight gain/maintenance and growth
Stamina for play or daily activities while ventilated
Freedom from active/recurrent infection, fever, deterioration
ATS Position Paper 1990

9. Interfaces Noninvasive vs. Invasive Age Cognitive ability Body habitus
Ventilatory needs
Anticipated length of ventilation
Family/patient preference

10. Noninvasive interfaces
Nasal masks
Full facemasks
Nasal pillows
Sipper mouthpiece
Lipseal/mouthpiece device

11. NIV: Nasal mask / Prongs
Many older patients prefer compared to mouthpiece
Problems:
Leak, especially mouth
Nasal bridge pressure with mask
Gum erosion or compression with mask
Nasal erosion with prongs
Chin strap may be needed

12. NIV: Full face mask Decreased leak Decreased
Cough
Talking
Eating
Increased risk of aspiration
Nocturnal use with daytime nasal mask

13. NIV: Sipper /Lipseal Mouthpiece
Daytime use
Allows facial freedom
Flexed mouthpiece +/- custom orthodontics
Intermittently used to augment breathing
Continuously used

14. Complications of NIV Facial and orthodontic changes
Aerophagia (PIP > 25 cmH2O)
Nasal drying/congestion = humidify
Volutrauma - air leak
Inadequate ventilation

15. Tracheostomies Shiley, Bivona, Portex and others
Pediatric sizes mimic ETT ID’s
Neonatal, pediatric, adult and customized lengths
Cuffed and uncuffed
Disposable inner cannula models

16. Tracheostomies

17. Ventilators

18. CPAP Continuous Positive Airway Pressure For simple sleep apnea
Stents open the airway
Decreases work of breathing

19. BiPAP Pressure Support Ventilation
IPAP—the inspiratory positive airway pressure—extra help when breathing in
EPAP—the expiratory positive airway pressure--CPAP
Cycles based on patient initiated breaths
Available with timed back-up rates
Used for severe sleep apnea, neuromuscular weakness or insufficiency

20. Full Ventilation Noninvasive or invasive
Pressure cycled or volume cycled
SIMV vs. AC
Allows pressure support, PEEP, inspiratory time, flow to be added and manipulated

21. Ventilator Choice Noninvasive vs. invasive Portability Battery life
Setting capabilities
Reliability
Community support

22. Ventilators Pressure cycled vs Volume cycled
Pressure cycled are often triggered by flow sensing reducing work of breathing
Flow sensing is also important in pts with high respiratory rates = infants/toddlers

23. Ventilators
Leak can vary with sleep, position, and effort which is problematic with volume cycled ventilators
Variable airway resistance and/or pulmonary or chest wall compliance better with volume settings
Pressure cycling limits ability to stack

24. Control vs. SIMV SIMV Modes Control Modes
Every breath is supported regardless of “trigger”
Can’t wean by decreasing rate
Patient may hyperventilate if agitated
Patient / vent asynchrony possible and may need sedation +/- paralysis
SIMV Modes
Vent tries to synchronize with pt’s effort
Patient takes “own” breaths in between (+/- PS)
Potential increased work of breathing
Can have patient / vent asynchrony
Control modes are used when complete control over the patient’s ventilation and/or oxygenation is desired. This is usually because the patient’s lung disease is significant enough that you that you wish to give maximal support. Another scenario may be one in which you want to precisely control the PaCO2, as in hyperventilation for increased intracranial pressure. Patients placed on control modes are often deeply sedated and may be given neuromuscular blockers.
SIMV modes are chosen when you want the patient to do as much work as they can tolerate and try to minimize the support from the ventilator. SIMV modes are used to wean patients; as you decrease the set rate, the patient will need to do more on their own to maintain normal blood gases. In control modes, if you decrease the rate, the patient’s spontaneous efforts will be fully supported so you will not know how much of that particular tidal volume they are generating on their own.
Note that for the paralyzed patient there is no significant difference between assist control and SIMV.

25. Control vs. SIMV CONTROL MODE SIMV MODE Every breath fully supported
Can’t wean by decreasing rate
Risk of hyperventilation if agitated
SIMV MODE
Vent synchronizes to support patient effort
Patient takes own breaths between vent breaths
Increased work of breathing vs. control

26. Assist Control Mode
Can trigger breaths, but needs support with each breath

27. SIMV Mode
Most patients, improved comfort, stable CO2s

28. Pressure vs. Volume Pressure Limited
Control FiO2 and MAP (oxygenation)
Still can influence ventilation somewhat (respiratory rate, PAP)
Decelerating flow pattern (lower PIP for same TV)
Volume Limited
Control minute ventilation
Still can influence oxygenation somewhat (FiO2, PEEP, I-time)
Square wave flow pattern
PRESSURE-LIMITED
I would not say that I have limited ability to affect ventilation in PC, though I may choose to increase the PAP recognizing that I accept the potential for increased baro/volutrauma at the same time
I also accept that I may suffer a decrease in ventilation with changes in compliance.
VOLUME-LIMITED
Accept that changes in compliance may lead to increases in peak airway pressures and associated baro/volutrauma.

29. Pressure vs. Volume Pressure Pitfalls Volume Vitriol
tidal volume by change suddenly as patient’s compliance changes
this can lead to hypoventilation or overexpansion of the lung
if ETT is obstructed acutely, delivered tidal volume will decrease
Volume Vitriol
no limit per se on PIP (usually vent will have upper pressure limit)
square wave(constant) flow pattern results in higher PIP for same tidal volume as compared to Pressure modes
Whichever mode one chooses, one needs to be aware of the limitations of that mode. In pressure modes, the tidal volume can drop resulting in hypoventilation or it can increase, leading to overdistention. With volume modes, the peak pressure can increase, resulting in barotrauma if the pulmonary compliance worsens. Regardless of the parameter that is controlled, the other must be monitored as it is a reflection of the compliance and hence the patient’s pulmonary function. Increasing peak pressures on volume mode (or decreasing tidal volumes in pressure modes) can also be a sign that the ETT is obstructed or of another problem with the ventilator circuit.

30. Pressure vs. Volume Volume No limit on pressure unless set Pressure
Square wave pattern results in higher pressure delivered for same volume delivered
Pressure
Tidal volume changes as patient compliance changes
Potential hypoventilation or overexpansion
Obstructed trach decreases delivered volume

31. Pressure vs. Volume Pressure control Set pressure, volume variable
Better control of oxygenation than ventilation
Better for younger, noncompliant lungs
Volume control
Set volume, pressure variable
Better control of ventilation than oxygenation
Better for older more compliant lungs

34. Need a hand?? Pressure Support
“Triggering” vent requires certain amount of work by patient
Can decrease work of breathing by providing flow during inspiration for patient triggered breaths
Can be given with spontaneous breaths in IMV modes or as stand alone mode without set rate
Flow-cycled
A patient needs to generate a certain amount of work in order to trigger it. Additionally, a patient has to breathe through an ETT that is almost always narrower than their own airway and ventilate the increased dead space imposed by the vent circuit. A patient may not be able to generate adequate tidal volumes for these reasons. To compensate for this increase in the work of breathing, pressure support is given. The ventilator generates pressure support by adding flow to the circuit during patient-triggered breaths in IMV or SIMV modes. This does not make it easier for the patient to trigger the ventilator but it does help the patient generate larger tidal volumes. Pressure support usually terminates when the flow in the circuit is 25% of the peak flow.

35. Pressure Support Trigger by patient
Provides inspiratory flow during inspiration
Given in addition to vent breaths in IMV modes or alone without a set rate, mimicking BiPAP

36. Bilevel Mode
Mimic BiPAP / No Backup Rate

37. Supporting Equipment External support—PEEP Alarms/Monitoring
Pulse oximetry, Apnea monitor, Capnography
Humidification
External w/ heater, HME
Airway clearance
Suctioning, Vest, cough assist
Talking devices

38. Discharge Criteria Presence of a stable airway FiO2 less than 40%
PCO2 safely maintained
Nutritional intake optimal
Other medical conditions well controlled
Above may vary if palliative care

39. Discharge Criteria
Goals and plans clarified with family and caregivers
Family and respite caregivers trained in the ventilation, clearance, prevention, evaluation and all equipment
Nursing support arranged for nighttime
Equipment lists developed and implemented with re-supply and funding addressed
Funding and insurance issues addressed

40. Continuing Assessment
Titration sleep studies
Blood gases
Bronchoscopy
Home monitoring
Used more frequently when weaning/decannulating

41. Complications Ventilator failure Tracheostomy issues
Decannulation, blockage, infection
Mask-related issues
Pressure sores, facial growth issues
Under- or over-ventilation

42. Outcomes Dependent on underlying disease
Over 70% 10-year survival, most deaths due to underlying disease
In retrospective studies, 0-8% of deaths were ventilator or technology-related
Occasional hospitalization

43. Quality of Life Generally good Some stress for patients, caregivers
Fewer hospitalizations
Better sleep quality
Better daytime functioning
Some stress for patients, caregivers
Related to amount of care and support needed

44. Home ventilation reality
Every patient is unique
These are guidelines not rules
Vary settings, interfaces, strategies to achieve goals of good health and optimized quality of life
Team approach necessary