1. What is CPAP?
1. What is CPAP?
He CPAP (Continuous Positive Airway Pressure) is a form of non-invasive respiratory support. It works by delivering a constant flow of air at a set pressure, which helps keep the airways and alveoli open.
Key analogy: Imagine you are trying to keep a balloon slightly inflated. CPAP is like blowing gently and continuously into the balloon to prevent it from deflating completely. This reduces the effort the baby has to make to breathe.
Airway
Collapsed (No CPAP)
Open (With CPAP)
CPAP prevents alveolar collapse at the end of expiration.
Checkpoint 💡
What is the main mechanism of action of CPAP?
2. When to start it?
2. When to start it?
CPAP is indicated in various situations of mild to moderate respiratory distress.
- ✓Respiratory Distress Syndrome (RDS): Especially in premature babies, as primary therapy.
- ✓Apnea of Prematurity: It helps stabilize the airway and stimulates breathing.
- ✓Post-extubation support: To prevent extubation failure and atelectrauma.
- ✓Transient Tachypnea of the Newborn (TTRN): Helps reabsorb lung fluid.
- ✓Pulmonary edema: Improves oxygenation.
Checkpoint 💡
A 32-week premature baby complains and has retractions. Would CPAP be a good initial option?
3. Initial Parameters
3. Initial Parameters
The success of CPAP depends on proper initiation. Here is an interactive guide.
Sets the pressure to keep the airway open.
Adjusts oxygen to reach target saturation.
Saturation Target (SpO₂): Generally 90-95% in premature babies and >92% in term infants.
Checkpoint 💡
For a full-term newborn with mild respiratory distress, what would be a reasonable starting point?
4. When and How to Modify the Parameters?
4. When and How to Modify the Parameters?
The key is continuous reevaluation. Adjusts the parameters according to the patient's symptoms, gases and oximetry.
⬆️ INCREASE Support if...
- Increased work of breathing: retractions, moaning, nasal flaring.
- FiO₂ requirements > 40-60%: Indicates that the current pressure is insufficient.
- Frequent or severe apneas.
- Respiratory acidosis in blood gas analysis (high PaCO₂).
As?: Increase PEEP/CPAP in steps of 1-2 cmH₂O (usually to a maximum of 8-10 cmH₂O).
⬇️ DECREASE Support if...
- Stable and comfortable patient.
- FiO₂ requirements < 30% and stable.
- Good lung expansion on Chest X-ray.
- Gasometry normalized or improving.
As?: First, lower FiO₂ to ~21-25%. Then, start lowering PEEP/CPAP in steps of 1 cmH₂O every 12-24 hours.
Checkpoint 💡
A child on CPAP with PEEP 6 and FiO₂ 50% persists with intercostal indrawing. What would you do first?
5. Weaning from CPAP
5. Weaning from CPAP
The ultimate goal is to free the patient from support. Weaning should be gradual and systematic.
Step 1: Starting Criteria
The patient must be clinically stable, with FiO₂ ≤ 25-30% and a PEEP/CPAP of 5 cmH₂O without signs of respiratory distress.
Step 2: Rest Periods ("CPAP off")
Once at minimum parameters (PEEP 4-5), you can try to suspend CPAP for short periods (e.g. 1-2 hours), closely monitoring the patient. Low-flow nasal cannula can be used during breaks.
Step 3: Successful Withdrawal
If the patient tolerates progressively longer periods without CPAP (e.g. up to 12-24 hours) without showing signs of failure (increased work of breathing, apneas, desaturations), support can be permanently removed.
Careful! Weaning failure is considered if the patient requires a return to previous parameters or needs increased support. Reevaluate the cause before trying again.
Checkpoint 💡
What is the first parameter that is usually completely weaned?
6. Practical Examples
6. Practical Examples
7. Final Evaluation
7. Final Evaluation
Time to test your knowledge! Answer the following questions.
1. A neonate with CPAP at 7 cmH₂O presents abdominal distension and poor perfusion. What is the most likely complication?
2. What is the main objective when using CPAP in a post-extubated patient?
3. It is decided to start weaning from CPAP. The patient is on PEEP 5 and FiO₂ 40%. What is the correct step?
4. What is "CPAP failure"?
5. When adjusting FiO₂ in an extremely preterm infant, what is a safe and commonly accepted SpO₂ target to balance oxygenation and risk of retinopathy?
📚 Bibliographic References
📚 Bibliographic References
1. De Paoli, A. G., Davis, P. G., & Lemyre, B. (2002). Nasal CPAP for neonates: what do we know in 2003?. *Current opinion in pediatrics*, 15(2), 169-174.
2. Morley, C. J., Davis, P. G., Doyle, L. W., Brion, L. P., Hascoet, J. M., & Carlin, J. B. (2008). Nasal CPAP or intubation at birth for very preterm infants. *New England Journal of Medicine*, 358(7), 700-708.
3. Dylag, A. M., & Tulledge-Scheitel, S. (2018). Weaning from noninvasive positive pressure ventilation. *Respiratory care*, 63(6), 765-777.
4. Committee on Fetus and Newborn. (2014). Respiratory support in preterm infants at birth. *Pediatrics*, 133(1), 171-174.