NON - INVASIVE VENTILATION
AT HOME
DR. D. K. PILLAI
07.09.2011
MUG @ UOM
ƒ In the beginning came ………….
OSA (HS)
1. CPAP – for
f OSAHS
(Obstructive Sleep Apnoea Hypopnoea Syndrome)
2 NIPPV
2.
(Non – invasive positive pressure ventilation)
Historically
ƒ First NIV – was iron lung for polio (negative pressure).
pressure)
ƒ Positive Pressure Ventilation with Intubation – ICU setting only.
ƒ Technological wizardry has produced compact, p
powerful, simple Positive Pressure Ventilators.
p
ƒ Doctors are more aware of their existence and indications.
ƒ Exponentially greater use in the West.
p
yg
Topics to be covered
Topics to be covered
¾ OSAHS
¾ OHS (Obesity Hypoventilation)
¾ ‐ DMD (Duchenne Muscular Dystrophy)
‐ POST POLIO ; MND POST POLIO MND ¾ Thoracic Restriction (post TB syndrome, severe kyphoscoliosis, ankylosing spondilitis)
OBESITY HYPOVENTILATION SYNDROME OBESITY
HYPOVENTILATION SYNDROME
(OHS)
• A worsening problem – in line with obesity epidemic.
• The higher the BMI, the more likely.
• 20% OSAHS have OHS.
• 90% OHV have OSAHS
OHS
OHS –
Pathophysiology
Alveolar Hypoventilation
yp
™ Fat, heavy chest wall.
™ Elevated, poorly moving diaphragm (abdominal fat).
™ Blunted response to hypoxia / hypercapnia.
™ Upper airway resistance (90% associated OSAHS).
™ Leptin resistance
OHS
Why is diagnosis important?
(a) MORTALITY at 18 months
‐ OHS
23%
%
‐ Obese, No OHS
9%
‐ OHS on NIPPV 3%
(b) MORBIDITY – habitual offenders in the very obese with OSAHS i.e., Metabolic, C di
Cardiovascular, Degenerative
l D
ti
How to diagnose OHS?
How to diagnose OHS?
• Anyone with BMI > 30, but especially > 35 kg.m‐
2 and PaO2 > 45 mmHg
• Symptoms – Snoring, apnoea, daytime somnolence
‐ Morning headaches, grogginess
‐ Daytime fatigue, dyspnoea, pedal oedema
• Signs – BMI, OSAHS, Cor Pulmonale
BMI OSAHS Cor Pulmonale
OHS
Laboratory tests
y
A. General
ƒ
ƒ
ƒ
Polycythaemia
Lipids, Thyroid
Cardiovascular
B. Specific
ƒ
ƒ
ƒ
Low Sp O2
Increased serum HCO3‐
Hypercapnia
yp
p ((> 45mm Pn
45
CO2)
C. Sleep study
OHS OHS
Treatment
1. Weight loss – may need bariatric surgery
2 CPAP
2. CPAP
3. NIPPV ‐ essentially BIPAP (Bilevel Positive Airways Pressure)
y
)
DUCHENNE MUSCULAR DYSTROPHY
DUCHENNE
MUSCULAR DYSTROPHY
(DMD)
¾ X linked recessive
¾ 1 in 3500 live after birth
(2 New cases annually here)
¾ Progressive muscular weakness
g
DMD
¾ 12 yrs ‐ Wheelchair
¾ Mid Teens – Lung Volume Loss, Scoliosis
g
,
¾ Age 18 –
A 8 20 ‐
Ventilatory failure
V til t f il
¾ If no Rx –
Death within 2 yrs
DMD
DMD –
Rx with NIV
Rx with NIV
¾ 5 yrs Survival : 70%
¾ May survive into Late 30
May survive into Late 30’ss
DMD ‐ monitoring
Annual – VC, Cough Peak Flow, SpO
,
g
, p 2
VC < 60% ‐ Sleep study annually
p
y
y
± wheelchair (REM Sleep disordered breathing)
VC < 40% ‐ Continuous Nocturnal Hypoventilation
‐ Start NIV (Rideau –
St t NIV (Rid
1980’s)
8 ’)
VC < 25% ‐ Daytime Ventilatory failure
‐ Ventilator dependence
DMD
DMD –
Cough failure
Cough failure
¾ NIV machine / Ambu Bag to “stack” breaths and produce a cough.
d
h
¾ Cough IN – EX ‐ Sufflator
OTHER DISEASES
OTHER DISEASES
9 POST POLIO SYNDROME
9 POST TUBERCULOSIS SYNDROME
9 SEVERE KYPHOSCOLIOSIS
NIPPV
Some practical aspects
VENTILATORY SUPPORT
ƒ NPV : Negative Pressure Ventilation
ƒ PPV : Positive pressure ventilation
Volume Targeted
(Volumetric)
Pressure Targeted
BPPV – Bilevel positive Pressure
Ventilation
e.g. BiPAP R
WHICH TO CHOOSE
WHICH TO CHOOSE
¾ No clear advantage of one over the other.
¾ BPPV used in vast majority of home ventilation, iirrespective of aetiology ti f ti l
‐ Cheaper, more comfortable
¾ Volume Targeted Ventilators used often in neuromuscular patients.
HOW DOES NOCTURNAL NIV WORK?
HOW DOES NOCTURNAL NIV WORK?
ƒ Relief of respiratory muscle fatigue.
ƒ Improved respiratory drive
(better response to hypercapnia)
? Decreased leptin resistance
ƒ Better sleep quality (less arousals)
MACHINE
MACHINE ‐
PATIENT INTERFACE
PATIENT INTERFACE
™ Extremely important
™ NASAL, NASOBUCCAL, FULL FACE MASKS
NASAL NASOBUCCAL FULL FACE MASKS
™ NASAL CUSHIONS
MACHINE
MACHINE ‐
PATIENT INTERFACE
PATIENT INTERFACE
¾ First session very important (and time consuming).
¾ Takes time to find a mask / cushion that fits patient nicely.
¾ Leaks
–
avoid strapping too tight.
ƒ Nose and mouth dryness
N d th d
‐ Chin Straps
Chi St
‐ Humidification