Transcript Noninvasive Oxygenation and Ventilation

Noninvasive Oxygenation
and Ventilation
Goals of noninvasive measures
 Either short term or long term support of
pulmonary function
 Short Term
– Hospital NC
– BiPAP for acute respiratory distress
 Long Term
– Home O2 for chronic COPDers
– CPAP for Obesity Hypoventilation Syndrome
or OSA
What goal for oxygen?
 COPDers
– Between 88 and 95%
– PaO2 >= 60
 Non-COPDers
– >= 92%
– PaO2 > 60
O2 Saturation vs. PaO2
 40-50-60 to 70-80-90 rule
PaO2
O2 Sat
40
70
50
60
80
90
Types of NIV
 Nasal Cannula
 Venti-Mask
 Non-rebreathers
 BiLevel
 CPAP
Non-Invasive Oxygenation:
Achieved FiO2
Venti-Mask colors
Non-Rebreather versus Partial
Non-rebreather
Non-Invasive Ventilation
 BiLevel
 CPAP (not discussed)
Advantages to Noninvasive
Ventilation
 No internal traumatic complications
 Decreased infections
 Less interference with communication and
swallowing
 Less need for sedation
Indications
 Well established
– COPD exacerbation
– Weaning in COPD patients
– Acute cardiogenic pulmonary edema
– Immunocompromised patients
– DNI patients
 Weaker indications
– Asthma exacerbations
– Cystic fibrosis
– Hypoxemic respiratory failure
– Extubation failure
NIV and COPD
 RCTs have shown
– 20-50% reduced intubation rate
– Improved RR, dyspnea and gas exchange
– Decreased length of stay
– Lowered mortality
 Intubated COPD patients who have failed T
“piece” trials
– Should be able to breath without assistance for 5
minutes
– Can tolerate levels of pressure generated by NIV
– Should not be “difficult” intubations
NIV and Asthma
 Physiological Rationale
– Decrease work of breathing
– Improve exchange
 Limited evidence
– No consistent recommendations for trial of NIV
in patients failing standard therapy
Acute Cardiogenic Pulmonary
Edema
 Physiology
– Recruits “flooded” alveoli
– Reduces preload and afterload
 RCTs have shown that BiPAP/CPAP can
– Improve dyspnea and oxygenation
– Lowers intubation rate
– Reduced intubation
– Reduced LOS
– Reduced mortality
Immunocompromised Patients
 Mechanical ventilation in these patients have a
high risk of
– Nosocomial infection (VAP) and septicemia
– Fatal airway hemorrhage caused by thrombocytopenia
and platelet dysfunction
 NIV begun in these patients before respiratory
failure becomes severe may halve mortality
 Greatest benefit with early initiation and singleorgan failure
Post-op Patients
 CPAP reduces intubation in patients after
abdominal surgery (reduces atelectasis)
 NIV improves outcomes in hypoxemic
respiratory failure after lung resection
Predictors of NIV success in
acute respiratory distress
 Cooperative patient
 Intact neurological function
 Good synchrony with ventilator
 APACHE score <29
 pH > 7.25
 Intact dentition
 Air leaking well-controlled
 Able to control secretions
Selection guidelines for use of
NIV in acute respiratory distress
 Appropriate diagnosis with potential
reversibility over hours to days
 Ascertain need for ventilatory assistance
– Moderate to severe respiratory distress
– Tachypnea (>24/min for COPD, >30/min for
hypoxemia
– Accessory muscle use or abdominal paradox
– Blood gas abnormality
– pH < 7.35, PaCO2 > 45 or PaO2/FiO2 < 200
Contraindications for NIV
 Respiratory arrest/Cardiac arrest
 Medically unstable (hemodynamically unstable,
arrythmias, cardiogenic shock/MI, GIB, ABG pH
< 7.1)
 Unable to protect airway (bulbar dysfunction,
AMS)
 Excessive secretions
 Uncooperative or agitated
 Unable to fit mask (facial trauma/surgery)
 Recent upper airway or GI surgery
BiLevel – What is it?
 IPAP (Inspiratory Positive Airway Pressure)
– Excess pressure to move air into lungs
 EPAP(Expiratory Positive Airway Pressure)
– Increased minimum lung pressure maintained
to increase alveolar recruitment
 PS (Pressure Support)
– PS = IPAP - EPAP
BiLevel – Setting?
 IPAP
– Usually 8-12 cm H2O
 EPAP
– Usually 4-5 cm H2O
BiLevel - Recheck
 A baseline ABG should be done during
initial episode of respiratory distress
 Patient should be followed-up in 1-2 hours
depending on condition after BiLevel NIV
is placed
BiLevel – Recheck Criteria
 Objective
–
–
–
–
Compare repeat ABG to baseline
PaO2/FiO2 should be > 150 after 1st hour
Gas Exchange: Oximetry, PaCO2, pH
RR, HR, BP, cough strength and ability to raise secretions should be
improved
 Subjective
– Comfort/Discomfort
– Feeling of dyspnea
 Ventilatory Function
– Synchrony
– Tidal Volume
– Airleaks
– Wave form
BiLevel - Complications