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

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

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

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

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

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

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

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

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

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

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

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

Optimum CPAP Comfortable baby / pink / normal BP No retraction / grunt No cyanosis / normal CRT CRT < 3 SEC SpO2 > 90-93 % ABG : PaO2 60-80 / PaCO2 40-45 /p H 7.30-7.40. Diagnosis ; Xray Chest in supine : Post. Intercostal space 7-8 (if > 8 : reduce PEEP / IF < 5 : raise PEEP) Dr. Gautam Ghosh

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

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 15-30 min after each setting. Dr. Gautam Ghosh

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

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

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

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

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

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, 8/5. 1280 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

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