10. Karolinska university hospital
• regional hospital, opened in 1937
• health care
• education and research connect the hospital
to Karolinska institutet
13. Fetal duct
• Essential for fetal circulation
• ”shunt” is right to left
• Fetal ductal closure can induce
primary pulmonary hypertension
14. Postnatal duct – term infant
• Shunt direction reversed
• Muscular tissue in the duct
sensitive to oxygen
• Duct closes during
the first days of life
15. Postnatal duct – preterm infant
• Constriction can be delayed
– pulmonary disease
– oxygenation problems
– inflammation
• Blood volume shunted through
the duct can be LARGE!
16. PDA – common clinical problem
PDA rate (%)
100
80
60
40
20
0
22 w 23 w 24 w 25 w 26 w
the EXPRESS study, all live-born infants <27 weeks in Sweden 2004-2007.
Acta Paediatrica 2010;99:978-992
26. PDA – what we really really mean
• ”diastolic flow easily detectable… main
pulmonary artery”
• ”diastolic backflow in the aorta immediately
beneath the ductus”
• ”LA-to-Ao-ratio >1.6”
* van Overmeire et al, New
Engl J Med 2000;343:674-81
27. PDA – what we really really mean
• ”left to right ductal shunting”
• ”increased LA-to-Ao-ratio”
• ”failure to wean from mechanical ventilation
* Richards et al, Pediatrics 2009;124:e287
29. PDA – review of definitions
*Zonnenberg, de Waal, Acta Paediatrica 2012;101:247-251
30. PDA – review of definitions
Criteria for definition of a significant PDA studies (n)
- not mentioned 3
- clinical only 7
- clinical and echocardiographic 44
- echocardiographic only 13
*Zonnenberg, de Waal, Acta Paediatrica 2012;101:247-251
32. Stethoscope ≠ good
• Murmur - good specificity, poor sensitivity
– hear a murmur - probably a PDA
– don’t hear a murmur - could be a PDA anyway
Skelton. J Peaditr Child Health. 1994;30:406
Davis. Arch Pediatr Adolesc. 1995;149:1136
33. ”I know it when I see it”
• Echocardiography!
• Echocardiography!
• Echocardiography!
34. My take
Visualise the problem with echo
Functional measurements first
Structural changes is a consequence of
functional changes (that you can measure)
35. My take
Functional measurements
• Ductal blood flow pattern
• End-diastolic velocity in LPA
• Diastolic flow in postductal aorta
Structural measurements
• LA/Ao-ratio
• Ductal diameter
36. My take
Functional measurements
• Ductal blood flow pattern: pulsatile
• End-diastolic velocity in LPA: >0.3 m/s
• Diastolic flow in postductal aorta: reversed
Structural measurements
• LA:Ao-ratio >1.4
• Ductal diameter >2 mm
37. My advice
Make your own definition and use it!
… until there is a validated definition.
Learn echocardiography!
40. Do you care about a PDA…
…as a risk factor for other
…as such, for example to
problems, such as BPD or
find ways to prevent it?
ROP?
41. ”PDA increase the risk of…”
• mechanical ventilation
• pulmonary haemorrhage
• NEC
• IVH / PVL
• ROP
• BPD
PDA is even related to
an increased mortality
42. Are these associations true?
• Conflicting results.
• Small studies!
• PDA treatment does not reduce risks.
44. Should PDAs be treated at all?
Benitz, Arch Dis Child Fetal Neonatal Ed 2012;97:F80-F82
45. Personal reflection
What we have…
• associations plausible
• underpowered studies
What we need…
• large observational studies
• placebo-controlled RCT
49. Medical treatment of sign PDA
Ibuprofen vs indomethacin (n=1092)
• Equal efficacy
• Ibuprofen – lower risk of NEC and transient
renal insufficiency.
• Studies need to evaluate long-term outcomes
50. Medical or surgical treatment
Surgery vs indomethacin (n=154)
• insufficient data to make a conclusion
• three recent studies indicates an increased
risk of BPD, ROP and neurosensory
impairment .
51. Dosing schedules – indomethacin
Several regimes
• slow injection vs infusion
• three doses vs six doses
• 0.2 mg/kg most common?
55. When is the shunt significant?
• ”…the shunt develops when the pulmonary
pressure drops during the first days in life”
56. When is the shunt significant?
It is not true that…
• ”…the shunt develops when the pulmonary
pressure drops during the first days in life”
57. Early ductal shunting
• Echocardiography!
• First hours of life:
– large shunt volumes
– most pronounced hemodynamic impact
– most strongly associated with morbidities
58. When to treat?
• Prophylactic treatment?
• Early ”pre-symtomatic” treatment?
• Treating the clinically apparent PDA?
59. When to treat?
…one of the big
unsanswered
questions in
neonatology.
60. DETECT trial
• infants <29 weeks
• echo within 12 hours
• infants with PDAs – indomethacin or placebo
• Results reported (PAS May 2012)
– reduced risk for lung hemorraghe
– no effect on other outcomes
63. Ibuprofen @ Karolinska
• Pro’s and con’s with both drugs.
• Change to ibuprofen in 2001
– less water balance problems
– cerebral circulation unaffected by ibuprofen
64. Current protocol
Echocardiography day 1-3
• ≤ 27 weeks
• any preterm on mechanical ventilation
Echocardiography day 4-5 (or later)
• preterm on CPAP and FiO2>0.30
• clinical suspicion
65. sign PDA
Contraindications?
• trombocytopenia Yes
• hyperbilirubinemia
• low urinary output Watchful waiting
• active NEC
• IVH grade 2-4
• DIC
No
Postnatal age?
• <14-21 days – ibuprofen
• >14-21 days – surgery
78. Our experience
• Transient renal dysfunction during ibuprofen treatment;
surveillance indicated.
• Short term closure achieved in most preterm infants.
• Surgical ligation common in 23-24 week infants,
due to relapses.
79. Conclusions
• More research!
• In the meantime, we should do our best!
7 April 2007 Stefan Johansson 79