Respiratory Highlights 2008
BWH NICU Nursing Blitz
1. Choice of Oscillator & Jet Ventilator
(15 min)
2. Choice of High Flow & Nasal CPAP
(20 to 30 min)
3. Trials in 2008 of CPAP & SIPAP
(5 min)
4. ROP Data & O2 Saturation Alarms
(10 min)
HFO Choice
Oscillator
Jet
Pressure/Volume
NEJM Sept. 13, 2007, Malhotra
Intracranial Blood Pressure Elevated
Elevated Intrathoracic
Pressure
( High PEEP & Paw)
Venous Return Impeded
Hepatic Veins Dilated
HFV Pressure Attenuation
Tracheal
Pressure
cm H2O
Amplitude may attenuate around a fixed Paw
20
CV
15
10
HFOV
5
HFJV
0
Proximal
Distal
Airways
Paw
Exhalation with HFOV
• Active exhalation, as with high-frequency oscillation (HFO),
can lead to gas trapping by lowering intraluminal pressure
disproportionately below pressure in surrounding alveoli,
thereby collapsing more proximal airways before exhalation is
complete.
• For that reason, users of HFO typically operate at higher mean
airway pressures than those used with HFJV.
• Elevating the baseline pressure during HFO, "splints" the
airways open while gas is actively withdrawn from alveoli.
Exhalation with HFJV
• During HFJV, exhaled gas swirls
outward around the incoming gas.
• The exhaled gas sweeps through
the CO2-rich deadspace gas.
• This action may help evacuate
CO2 and enhance ventilation.
• Small VT is readily exhaled
without trapping during
short exhalation time.
CHOKE POINTS may develop when:
• airways lack structural strength
• the chest is squeezed
• gas is sucked out of the airway
• Back pressure (High PEEP/Paw) may splint
open the airway and allow gas to exit
PEEP
+
+
+
+
+
The 6 Jet Fundamentals
1. HFJV P (PIP - PEEP)  PaCO2
•
HFJV Rate is secondary
2. FRC and MAP  PaO2
3.  PEEP to avoid hyperventilation and hypoxemia
4. If  CV Rate  oxygenation, PEEP is probably
too low
5.  CV settings whenever possible
•
Especially when airleaks are a concern
6.  FiO2 before PEEP until FiO2 < 0.5
Ventilation and HFJV
25
PIP
20
15
P
10
PEEP
5
0
time
Raising PIP or lowering PEEP
VT which
PCO2
Recruitment Strategy for RDS
• Find the Critical Opening Pressure of the
alveoli
• Optimize PEEP to stabilize the alveoli
• Reduce PIP as recruitment proceeds
• HFJV may reduce volutrauma in
surfactant deficient lungs
HFJV - RDS Study Summary
* of BPD at 36 wks PCA.
• HFJV reduced the incidence
• HFJV reduced PIP and P compared to CV.
• HFJV "optimal-volume strategy" resulted in less hypocarbia and better oxygenation than low-volume strategy.
• HFJV "optimal-volume strategy" was associated with
lower incidence of severe neuroimaging abnormalities
compared to low-volume strategy.
* Keszler, et al. Peds 1997; 100:593-599.
HFO / HFJV
choice
•High PIP & FiO2
conventional
•PIE per CXR
•Need for nitric oxide
•When Jet fails
choice
•PIE despite HFO
•Air leak syndromes
•Excessive secretions
•Hemodynamic
compromise
•When HFOV fails
Oxygenation –
• HFO
–FiO2
–MAP
• Jet-Particularly effective with
non-homogeneous disease.
–FiO2
–PEEP
–CV rate
–CV PIP
–CV I time
Ventilation –
• HFO
• Jet
–Amplitude
–Raise PIP
–MAP to optimize
–Raise rate
position on inflation
–Change PEEP
curve
–Rate (lower to
drop PaCO2)
Bubble CPAP
HF Nasal
Cannula
RDS,
apnea
&
http://www.surfneon.com/cpapbwh.swf
post-extubation support
B
U
B
B
L
E
C
P
A
P
DuoDerm
•Nare protection from CPAP prongs
•Nasal seal for CPAP prongs
Bruised Nasal Septum /Mepitac use under Cannulaide
CPAP
design
CPAP
design
for a
contented
family…
“On the basis of our findings, we suggest that highflow nasal cannula should not be used as a routine
replacement for CPAP therapy.”
Tight cannula obstructs nares.
Cannula flow will not meet baby’s flow demand.
Flow directed into nasopharynx not at stable pressure
Anatomic variants of nare size & structure alter
cannula seal. Clinically relevant pressure is achieved
only on the smallest of babies.
Poor humidification
•Airway dysfunction
• mucocilliary transport
•Increased fluid osmolarity
•Promotion of bronchospasm
• secretion viscosity
•Impaired nutrition
•Impaired growth
•Mucosal injury
•infection
Trial:
Airlife
CPAP
&
BIPAP
CPAP
Maine Med Portland
St/ Margaret’s Dorchester
MY SAT
LIMITS ARE:
HIGH: 93
LOW: 85
• Ford S. Leick-Rude MK, Meinert K, Anderson B, Sheehan M,
Haney B, Leeks S, Simon S, Jackson J. Overcoming Barriers
to Oxygen Saturation Targeting. Pediatrics 2006 118 Suppl
2:S177-186
• Phelps, D., Goldsmith, JP, Retinopathy of Prematurity Hot
Topics Dec. 4, 2007