Surfactant better as infusion than as bolus (in animals) - less inactivation?
The more doses the better the effect...
Effective in term babies with resp failure (ie less ECMO).
Routine intrapartum oropharyngeal and nasopharyngeal suctioning of term-gestation infants born through Meconium Stained Amniotic Fluid does not prevent MAS.(n=2500, Lancet 2004)
Transcervical amnioinfusion with saline for women with thick meconium staining in labour does not prevent MAS (n=2000, New England Journal of Medicine 2005;353:909).
Inhaled NO avoids ECMO in term babies. Most obvious benefit is for meconium aspiration with Oxygen Index over 20. Used also for Congenital diaphragmatic hernias and sepsis but benefits dubious. Although mostly a vasodilator, it has diverse effects including bronchodilation, angiogenesis; in fact, could be said to drive fetal adaptation.
Cochrane reports on 11 studies in preterms: highlights different strategies, but concludes:
Data from Chicago (New England Journal of Medicine 2003;349:2099-107). So role as prophylaxis vs BPD?
=Surfactant deficiency. Associated with prematurity but occasionally still affects babies at term.
ATECS study 2005 showed that antenatal steroids effective in elective LSCS! A more cost-effective policy option would be to give only to diabetics going for elective section.
Traditionally late fibroproliferation but now with surfactant it's all a bit different. Some ex prems get chronic lung disease who required little in the way of early ventilatory support, and this seems to be a problem with distal lung growth. Definition is now O2 requirement at 36/40 corrected (if you were less than 32/40), or at 28/7 if you were more than 32/40 - but depends on saturation criteria! Associated with PaCO2, reflecting volutrauma; PDA (fluid overload?); chorioamnionitis (toxins disrupt lung growth?).
Ventilator strategies: permissive hypercapnoea. PTV does not change outcome but shortens weaning from ventilator. No benefit from prophylactic CPAP for 28-31 weekers.Arch Fet 2004; 89
HFOV conflicting results; benefit from 1 trial in which only moderate/severe cases were entered.
Fluid restriction does not help, but avoiding excessive sodium and fluid probably useful. Nutrition is obviously important but excessive weight gain (crossing centiles) is bad.
Evidence of decreased Surfactant protein sp-b/c production in BPD - role for late surfactant?
Steroids improve lung mechanics and gas exchange. Early steroids reduce BPD but increased mortality and adverse effects on head growth, although most of these trials used prolonged courses so shorter courses may not carry same risks. Inhaled steroids, disappointingly, do not seem to help.
Multiple antenatal courses of dexamethasone but not betamethasone were associated with an increased risk of leukomalacia and 2-year infant neurodevelopmental abnormalities. (AmJObsGyn 2004)
Comparing centres using lots of home oxygen with those that don't, the babies get discharged earlier and stay on oxygen longer, but GP/community visits are reduced (admissions are the same) so overall costs are the same. Morbidity is no different. Anne Greenough, Eur J Pediatr. 2004 Jun;163
O2 dependency at 2yr unlikely to improve.
Caffeine reduces BPD from 47-36% of VLBW! N Engl J Med. 2006 May 18;354(20):2112-21.
Fryn's syndrome- coarse facies, diaph hernia, cardiac. High mortality even with surgery...
Caffeine is a respiratory stimulant, useful for preterms who have immature respiratory centres and patterns. NNT=3 to prevent apnoea, 13 to prevent IPPV. No role prophylactically! NNT=3.7 for use post extubation, to prevent failing. Less side effects cf theophylline. High dose (20mg/kg) better (and even seems to shorten time on ventilator!). Suggestion that you get less BPD cf placebo (see above)! But you seem to get worse weight gain. Also impairs cranial/intestinal blood flow on doppler, which is slightly worrying, although there is no definite increase in IVH or NEC.
Steer
Haemorrhagic pulmonary oedema is probably more accurate. Thought to be similar to high altitude pulmonary oedema, where there is stress failure of the pulmonary capillaries. A sudden event seen typically in the first few days of life in association with RDS, accompanied by respiratory deterioration as well as cardiovascular collapse and coagulopathy.
Antenatal steroids appear to reduce the risk. Thrombocytopenia seems to increase the risk. Can occasionally occur in the second or third week of life, often in association with a patent ductus.
The diagnosis is usually obvious. CXR will show bilateral white out. Management is supportive - ventilatory support (high PEEP may have a splinting effect), sedation/paralysis (to lower pulmonary vascular resistance), blood products.
Has a high mortality. Survivors are also more likely to have severe intraventricular haemorrhage.
Can also be seen in term babies, where it typically accompanies meconium aspiration or some other lung pathology requiring positive pressure ventilation at birth - usually occurs in the first 12 hours of life.
J Perinat 2000;5: 295
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