Non-Invasive Ventilation Flashcards
Use of Non-Invasive Ventilation Frequency
Before only CPAP was being used but now BiPAP is on the rise
BiPAP is more effective than CPAP in reducing extubation failure as it will augment ventilation
Advantages of NIV in Infants
Reduction in number of infants requiring intubation and ventilation
Shortened course of ventilation by facilitating earlier weaning
Treatment for difficult apneas
Treatment for infants with chronic lung disease
*Further improvements in all of the above seen with BIPAP over CPAP!
Non-Invasive Ventilation Interfaces
Typically used without an artificial airway
Nasal prongs and nasal masks most common
*Sizing for the SiPAP machine is very important
SiPAP
Will give us a baseline pressure
SiPAP Machine
SiPAP is a brand name seen
- Less expiratory resistance due to the specially designed flow generator (incorporated flip flop gate)
- The flip flop gate will effective manage the baseline pressure that is delivered to the baby
- More stable pressures are delivered
- Provides a baseline pressure
- Uses a demand system that allows for lower flows to be used
- Used for spontaneous breathing patients as they will be triggering the BiPAP
- SiPAP uses the Graesby capsule
Broad Purpose of Non-Invasive Ventilation
*The broad purpose of non-invasive ventilation is to treat respiratory dysfunction and restore respiratory gas exchange in a range of clinical settings
Non-Invasive Positive Pressure Ventilation (NPPV)
A method of respiratory assistance that involves an external interface and cyclical positive pressure device
Negative Pressure Assisted Ventilation (NPAV)
A method of respiratory assistance based on intermittent application of sub atmospheric pressure external to the chest wall through a tank or mold
Used for kyphoscoliosis
Continuous positive airway pressure (CPAP)
A method of respiratory assistance based on application of distending flow via external interface to attain a defined constant positive pressure
High-Flow Nasal Cannula (HFNC)
A means of respiratory assistance that utilizes a soft nasal cannula interface and high humidified flow source to raise the intraluminal pharyngeal pressure
Will always be humidified
FiO2 is set via a blender
Flow rate is often set to 1 lpm, but can be as high as 5
Very effective
High flow nasal cannula=irritation therapy. Prost does not believe that it is given actual CPAP
Contraindications to NIV
- The need for intubation and mechanical ventilation:
- Nasal obstruction or severe upper airway malformation
- Choanal atresia, Cleft palate, TE fistula
- Severe cardiovascular instability and impending arrest
- Untreated CDH
- Unstable respiratory drive with frequent apneic episodes
- Resulting in desaturation associated with/without bradycardia
- Ventilatory failure (PaCO2 > 60 mmHg and pH < 7.25)
- History of recent GI surgery
- Bronchiolitis is a relative contraindication as hyperinflation may result 2° obstructive airways disease.
NIV Waveforms
Variable flow in CPAP systems are seen in machines such as Arabella and are the most desirable
Systems like the Arabella will use a demand system (flip flop gate) and use a lower flow on expiration
Sechrist systems will deliver a constant flow
Does CPAP augument vetilation
CPAP does not augment ventilation rather it is an interface that helps with oxygenation and WOB (improve compliance and FRC which in turn improves ventilation)
No matter how perfect we try to make our machines we will get slight ossiclations
Levels 5 and 6 seems to work well for most patients
Important Considerations with NIV
- Prongs/tubes must be checked periodically for patency
- Can become kinked or occluded with secretions (this is one of the biggest complications)
- Pressure necrosis, nasal irritation or septal distortion can result
- Nasal septal breakdown is very common!
- To minimize/prevent:
- Make sure they are secured properly!
- Calgary Health Region switches between mask and the nasal prongs at least Q6h
- When we use too much PEEP in babies, the capillary bed is so fine if you overinflate the alveoli you impede pulmonary circulation
What will small increases in CPAP do
Small increases in CPAP can change lung volumes by 4-6 ml/kg
Because the volumes are so low deadspace is a big problem
BiPhasic Ventilation
- Allows the infant to breath spontaneously at either a high or low pressure
- User will set RR and inspiratory time
- BP-NCPAP may be used safety and effectively to assist in weaning from mechanical ventilation
- However the effectiveness and safety of BP NCPAP compared to NCAPA need to be confirmed in a large multi-center trail
CPAP
Spontaneous breathing can be supported with CPAP, which is a mode that maintains constant pressure above baseline throughout inspiration and expiration
CPAP works by maintaining inspiratory and expiratory pressure above ambient, which will improve FRC and static lung compliance
Patient need to maintain adequate minute volume while breathing spontaneously because ventilatory support is not provided
Indications of CPAP
-
Arterial oxygenation is inadequate despite elevated FiO2
- Usually accompanied with signs of respiratory distress
- PaO2 is less than 50 mmHg while the infant is breathing FiO2 of 0.60
- Provided that Minute Ventilation is adequate
- PaCO2 is 50 mmHg and pH is 7.25
-
Abnormalities on the physical examination
- Tachypnea (30% above normal), retractions, grunting, nasal flaring, cyanosis or pale, agitation
- Poorly expanded and/or infiltrated lungs on CXR
- A condition responsive to CPAP plus one of the above
- Very low birth weight babies at risk for RDS (+ surfactant)
- For administration of NO to spontaneously breathing babies
General Categories of Conditions that Use CPAP
Respiratory Distress
Abnormal Breathing Pattern
Lung Diseases
Conditions that Use CPAP
Respirtory Distress
Tachypnea
Retractions or accessory muscle use
Grunting
Nasal Flaring
Head Bobbing
Conditions that Use CPAP
Abnormal Breathing Pattern
Apnea of prematurity
Obstructive sleep apnea
Conditions that Use CPAP
Lung Diseases
Decreased lung volumes
Pneumonia
Tracheomalacia
Pulmonary Edema
RDS
Atelectasis
TTNB
Tracheal malacia or other airway abnormality
Conditions that Use CPAP
Other
Post extubation failure
Objectives in Use of Non-Invasive Mechanical Ventilation in Pediatrics
The primary objective of NPPV are to decrease the WOB and improve respiratory gas exchange
- Decreased WOB manifested by
- Decreased RR
- Decreased retractions
- Decreased use of accessory muscle of breathing
- Improved respiratory gas exchange manifested by
- Decreased arterial PaCO2
- Increased arterial PaO2
- Increased arterial pH
- Increased FRC
- Increased patency of oral pharyngeal airway and decrease intrinsic auto PEEP
Acute Respiratory Disorders in Neonatal and Pediatric Patients Responsive to NPPV
Early phase ARDS
Acute chest syndrome
Congenital Heart disease
Complicated community acquired pneumonia
Pulmonary edema
Fat or bone marrow embolism
Status asthmatics
Post extubation respiratory distress
Acute pulmonary hemorrhage
Near drowning lung injury
Acute lung aspiration syndrome
Bronchiolitis
Acute respiratory distress post bone marrow transplantation
Factors Informing the Success or Failure of NPPV in Treatment of Acute Respiratory Distress in Children
- Assignment of skilled personnel to monitor and manage critically ill child
- Availability of appropriate NPPV equipment and monitoring devices
- Level of postnatal development and status of airway protective reflexes
- Exclusion of children with rapidly evolving:
- Hypoxemia
- Cardiovascular instability
- ARDS
- Severe asthma
Methods of Applying CPAP
- Nasal prongs
- Most common
- Nasal pharyngeal prongs
- Only progress to nasal pharyngeal if it is thought that the infants apneas will be relived by stimulation of the nasal pharynx by the flow.
- Non-invasive nasal masks
- Nasal pharyngeal tubes
- Trimmed ETT
- ETT
- Don’t do this for long periods clinically due to the WOB imposed by the tube. It will be done short term (< 2 hours generally) to assess if patient is ready to be extubated.
- Can also temporarily apply it with a JR bagger and mask
Methods of Applying CPAP
Arabella System
This is the most common method seen to provide NIV to the infant
Can use nasal prongs or nasal mask
Increasing use of simple nasal prongs to deliver flow and pressure to neonates
Applications of some CPAP and flow may help with apnea and bradycardia prevention
Do you set flow or pressure in CPAP
With CPAP set the flow to get the pressure you need (you don’t set pressure because of the leaks)
Bubble CPAP
You put gas through bubbles which we think will make an oscillator effect through vibration
So we are getting CPAP and vibration therapy (ossiliation)
The level of CPAP is not as effect as what it is on SiPAP
Monitoring the Patient on NIPPV
- ABG
- TcK (PCO2 & PO2)
- SpO2
- RR
- HR
- WOB
- With non invasive ventilation there is much less hard data such as Vt and monitor interaction variables
- Transcutaneous monitoring needs to be re calibrated often.
- If you are doing a blood gas make sure to re-calibrate it and then do the blood gas
ABG of Normal Preterm Infant (5 Days)
pH- 7.35-7.45
PCO2- 35-45
PO2- 85-100
HCO3- 22-26
BE- -2 to +2
ABG of Normal Preterm Infant (5 Days)
pH- 7.34 to 7.42
PCO2- 32 to 41
PO2- 62 to 92
HCO3- 19 to 23
BE- -5.8 to -1.2
ABG of Normal Term Infant at 5 Hours
pH- 7.31 to 7.37
PCO2- 32 to 39
PO2- 62 to 86
HCO3- 18 to 21
BE- - 6 to -2
ABG of Normal Preterm Infant at 1-5 Hours
pH- 7.29-7.37
PCO2- 39-56
PO2- 52-68
HCO3- 22-23
BE- -5 to -2.2
Wht will happen to the ABG if the baby is crying
If they are crying and are vigorous they will be more acidotic
ABG of Very Low Body Weight
28-40 Week GA
pH Greater than or equal 7.25
PCO2 45-55
PO2 50-70
HCO3- 18-20
SpO2 85-92
ABG of Extremely Low Body Weight
<28 Week GA
pH Greater than or equal 7.25
PCO2 45-55
PO2 45-65
HCO3- 15-28
SpO2 85-92
PowerPoint Initiation of CPAP
CPAP is initiated at levels of 4-5 cmH2O
CPAP can in increased up to 10 cmH2O Provided the following
*These are also what we look at to assess how well CPAP is working
- Stabilization of FiO2requirements 0.60 with PaO2levels >50 mmHg or the presence of Clinically acceptable non-invasive monitoring of O2(PtcO2) while maintaining an adequate VE as indicated by PaCO2of 50-60 and pH 7.25
- Reduced WOB as indicated by decreased RR, retractions, grunting, and nasal flaring
- Improvements in lung volumes and appearance of lung as indicated by chest radiograph
- Improvement in patient comfort as assessed by the bedside caregiver
BiPhasic Mode Basic Settings
6/9
7/10
Rate: 20
Ti: 1 sec.
Separation of 3 cmH2O
Settings for BP-NCPAP
FiO2 >0.5
Upper CPAP 10
Lower CPAP 7
Settings for BP-NCPAP
FiO2 0.30-0.5
Upper CPAP 9
Lower CPAP 6
Settings for BP-NCPAP
FiO2<0.30
Upper CPAP 8
Lower CPAP 5
Settings for NCPAP
FiO2 <0.30
CPAP 5
Settings for NCPAP
FiO2 0.30-0.5
CPAP 6
Settings for NCPAP
FiO2 >0.5
CPAP 7
BiPhasic Mode Basic Settings
6/9
7/10
Rate: 20
Ti: 1 sec.
Separation of 3 cmH2O
Non-Invasive Ventilation in Pediatrics
Objectives For Respiratory Disorders
Decreased WOB
Increased ventilation
Increased FRC
Upper airway patency
Non-Invasive Ventilation in Pediatrics
Objectives For Chronic Disorders
Theses have not been proven conclusively
Improve quality of sleep
Reduce daytime symptoms
Decrease CO2
Prevent atelectasis
Maintain FRC
Increase lung compliance
Rest respiratory muscles
Non-Invasive Ventilation in Pediatrics
Respiratory Distress
There is not a lot of randomized controlled trails to show the effectiveness of non-invasive ventilation as treatment for respiratory distress
However when used in the right setting for hypoxemic and/or hypercarbic patients can be beneficial
Non-Invasive Ventilation in Pediatrics
Acute Care Settings
- Early ARDS
- Pneumonia
- Pulmonary edema
- Post op upper airway obstruction
- Atelectasis
- Hypercarbic CF exacerbation
- Asthma with hypoxemia
- Post extubation distress
- Near drowning
- Acute decompensating of NMD-SMA, Duchenne’s MD
Non-Invasive Ventilation in Pediatrics
Chronic Care Settings
- Neuromuscular Diseases
- Spinal muscle atrophy (SMA)
- Duchenne’s
- Rib cage and chest wall anomalies
- Restrictive lung diseases
- Advanced CF
- Central alveolar hypoventilation
- Laryngotracheomalacia
- Chronic upper airway obstruction
- Morbid obesity
Pediatric Positive Pressure Devices
Pressure Targeted
- BiLevel/BiPAP
- BiLevel is pressure support
- When there is a high WOB we will use pressure support rather than CPAP
- Same as in adults
- Will have IPAP and EPAP
Pediatric Positive Pressure Devices
Pressure Targeted Advantages
Leak compensation
Spontaneous and time modes
Pediatric Positive Pressure Devices
Volume Targeted
Portable home ventilators
Most devices do not have a pressure support feature
Do not trigger well or support spontaneous breathing
Set up so Vt is greater than physiologic Vt
NPPV Modes
Same as adult modes
CPAP
Spontaneous
Timed
Spontaneous/Timed
Pediatric NPPV Interfaces
Similar to adults
Nasal pillows, masks
Face masks reserved for critically ill
Ped NIV – Complications/Contraindications
- Skin irritation
- Nasal dryness
- Eye irritation
- Aspiration
- Reflux
- Leaks
-
Cardiovascular instability
- Absolute contraindication
Factors Unique to Pediatric Patients that Promote Complications of NPPV
-
Aspiration
- Immaturity of airway protective reflexes
-
Reflux
- Impaired gastroesophageal sphincter function during infancy
-
Upper Airway Obstruction
- Anatomical factors
- Difficulty clearing secretions
-
Large oral leak
- Tendency to mouth breath
-
Agitation
- Anxiety, incomplete understanding, developmental disorders
Monitoring Effectiveness in NIPPV in Peds
- Decreased WOB
- Improvements in Respiratory Gas Exchange
- Increase in FRC
- Maintenance of Upper Airway Patency
Monitoring Effectiveness in NIPPV in Peds
Decreased WOB
Assess during the physical assessment
Looking for a decrease in RR, retractions, and use of accessory muscles
Not reliable in young children and infants with neuromuscular and central disorders
Monitoring Effectiveness in NIPPV in Peds
Improvements in Respiratory Gas Exchange
- Assessed via Pulse oximetry while looking for acute improvements in SpO2
- Not a reliable metric in the assessment of hypoventilation
- Interpretation obscured by concurrent O2 treatment
- Assessed through blood gas sampling
- Increase in pH, decrease in PaCO2, increase PaO2
- PaCO2 may not decrease for hours if at all in some disorders
- It is an invasive measure
- End-Tidal CO2 Monitoring
- Acute reduction in end tidal CO2
- High background flow in NPPV circuit can wash out expired CO2
- Transcutaneous CO2 Monitoring
- Subacute reduction in transcutaneous CO2 monitoring
- Accuracy dependent on careful electrodes placement
- Changes lag minutes behind change in actual PaCO2
Monitoring Effectiveness in NIPPV in Peds
Increase in FRC
Assessed through a routine chest radiography to see an increased lung expansion, decreased atelectasis
Difficult to accomplish during therapy
Changes can lag days behind
Monitoring Effectiveness in NIPPV in Peds
Maintenance of Upper Airway Patency
- Assess through sleep polysomnography to look for sub-actute reduction in the number of airway-occlusive episode to decrease with the degree of thoracoabdominal asynchrony
- Not amendable to acute clinical setting
