1. CPAP Workshop Dr. Gautam Ghosh Dr. Chandan Roy Dr. Ashok Modi
Dr. Debjani Gupta
Dr. Amit Roy
Dr. Gautam Ghosh

2. Definition
CPAP : It is a modality of respiratory support in which increased pulmonary pressure is provided artificially during the expiratory phase of the respiration in a spontaneously breathing neonate.
IPPV or IMV : Breathing is taken over completely by the machine & increased pulmonary pressure occurs during both inspiration & expiration.
Dr. Gautam Ghosh

3. Historical review Poulton & Oxam 1936 Gregory et. Al 1971: first trial
Agostino et.al 1973 : first RDS managed with CPAP.
Bubble & Dual flow CPAP (Infant flow drive)
Dr. Gautam Ghosh

4. Types of CPAP Oxygen hood Bubble CPAP & Dual flow CPAP machine
Ventilator
Dr. Gautam Ghosh

5. Physiological effects
Organ System
Benefit
Risk
Pulmonary
FRC / Static compliance / Pa02
IP Shunt/ WOB / PVR
Splinting airway& diaphragm /surfactant +++
Air-leak syndrome / Decreased compliance at high pressure.
CVS/ CNS
CPP = MABP( ) --- ICP ( )
VR / CO
ICT/
Renal /GIT
ADH /Aldos.
Urine / Gut distension
Dr. Gautam Ghosh

6. Various Modes of CPAP Methods Advantages Disadvantages ET Tube
Stable ++/ good control & ventilator access
Invasive / Airway resistance ++
Nasal Prongs
Easy / low resistance /easy feeding / non-invasive
Septal erosion /nasal obstruction /abd. distension
Nasopharyng. tube
Non-invasive / easy feeding
Leaks /pressure necrosis/abd. distension
Mask
CPAP mask
Easiest application
Oral care difficult /leak / aspiration
Head box
Easy application
Leak /high flow 02 / access difficult
Dr. Gautam Ghosh

7. Newer CPAP
Bubble CPAP : vibration (high frequency?) / may be less CLD (?)
Dual flow : Infant flow driver / fluidic flip mechanism / more stable PEEP control / failed nasal CPAP – try Dual flow CPAP—failed –try IMV
Dr. Gautam Ghosh

8. Effect on Blood gases
Oxygen : Improves due to increase in FRC through recruitment of atelectatic alveoli.
CO2 : Decreases due to availability of greater surface area for gas exchange due to recruitment of alveoli. Excessive CPAP(> 7 cm) leads to over-distension of alveoli and CO2 retention.
CPAP improves p O2, p CO2 change is secondary.
Dr. Gautam Ghosh

9. Fi O2 controlled from 0.2 to 1.0 with CPAP.
CPAP Ranges
Ranges
ET Tube
Nasal
Comment
Low
3—4
4—5
CPAP< 3 not useful
Medium
5—7
6—8
Good range
High
8--10
9--10
Adverse effects common
Fi O2 controlled from 0.2 to 1.0 with CPAP.
Dr. Gautam Ghosh

10. Indications of CPAP
Respiratory distress, moderate /severe: retraction or grunt.
Recurrent apnea
P aO2 < 60 with FiO2 > 0.6 ( O2 hood).
Early : within 2 hrs of distress.
Late ; after FiO2 requirement > 0.6
Dr. Gautam Ghosh

11. Guidelines for CPAP Start with nasal CPAP of 5—6 cm & FiO2 0.4—0.5
Increase CPAP by 1 cm if required
Reach a CPAP of 8—9 cm.
Now increase FiO2 in small steps of 0.05 up to 0.8
Clinical /ABG / SpO2 > 30min in each step
Do not raise FiO2 before pressure : may remove hypoxic stimulus -- apnea
Revert to IMV if not responding
Dr. Gautam Ghosh

12. Weaning from CPAP Reduce nasal CPAP TO 8 cm Reduce FiO2 by 0.05 to 0.4
Reduce CPAP by 1 cm decrements
Reach a level of CPAP 4cm / FiO2 0.4
Remove CPAP and replace a O2 hood.
Dr. Gautam Ghosh

13. Optimum CPAP Comfortable baby / pink / normal BP No retraction / grunt
No cyanosis / normal CRT
CRT < 3 SEC
SpO2 > %
ABG : PaO / PaCO /p H
Diagnosis ; Xray Chest in supine : Post. Intercostal space 7-8 (if > 8 : reduce PEEP / IF < 5 : raise PEEP)
Dr. Gautam Ghosh

14. Failure of CPAP Retraction / Grunt ++ Apnea on CPAP
PaO2 < 50 in FiO2 > 0.8 ( nasal CPAP >8cm)
PaCO2 > 55
Baby not tolerating CPAP.
Commonest cause : delay in starting
Dr. Gautam Ghosh

15. Monitoring CPAP
Clinical : comfort /RR,grunt,retraction /Cyanosis/HR, pulse / CRT,BP / Temp ./ Abd.girth / Urine / CPAP machine
Pulse Oximetry ; set alarm at 88%(L) & 95%(H).
ABG : wait for min after each setting.
Dr. Gautam Ghosh

16. Practical Points in CPAP
Warm gases at 34—37* C & humidify.
Gas flow (21/2 times minute ventilation) at 5-8 L/M minimum
Look for nasal or oral blocks by secretion
Oro-gastric suction is a must
Stabilize the head with a cap and string
Change CPAP circuit/prong every 3 days
Asepsis.
Sedation ??
Feed : oro-gastric 10 ml/kg EBM
Dr. Gautam Ghosh

17. CPAP & RDS Prevent atelectasis/ preserve surfactant / avoid IMV
Early better than late / no role in prophylactic CPAP
INSURE : intubate / surfactant /extubate / CPAP with early signs( a/A o2 <0.36)
Surfactant by CPAP ; future ??
Dr. Gautam Ghosh

18. CPAP & Other disease
CPAP after extubaion : Nasal better than ET tube CPAP / SNIPP (synchronised nasal intermittent positive pressure ventilation)
MAS : better in atelectatic than over-inflated lung
Dr. Gautam Ghosh

19. Complications of CPAP
PAL : tends to occur when O2requirements are decreasing & compliance improving
Excess PEEP : V /Q mismatch due to excess flow in under-ventilated lungs.
Dr. Gautam Ghosh

20. Future
With chance of cost of surfactant coming down in future, CPAP may be a better alternative in RDS.
Noninvasive ventilation
Dr. Gautam Ghosh

21. Case 1
30wks, Uncontrolled APH, 30 yrs , 4th gravida, P 1+2, LUCS, 1 dose Dexa 12 hr before birth
BVm with 100% O2for resuscitation, APGAR 5/1, 8/ gms female
Cord blood PCV 56%, Sepsis screen –ve, gastric aspirate shake test –ve.
1hr: tachypnea, retractions, Spo2 82%
Put on O2 hood (Fio2 0.5)
Dr. Gautam Ghosh

22. ABG tree ABG CORD 1 HR (hood) 6HR (CPAP) 14HR (IMV?) p H 7.30 7.32
7.20
7.25
Pa CO2 53 52 45 41
PaO2 39
82.9 55 65
HCO3 25 26 23 16
SpO2 91 90 86
Dr. Gautam Ghosh