title: Transient pulmonary vascular lability: a form of mild pulmonary hypertension of the newborn not requiring mechanical ventilation.
abstract: Infants at risk for the development of persistent pulmonary hypertension of the newborn (PPHN) may require hyperventilation and muscle relaxation to improve lung compliance and oxygenation. During a 16-month period from June 1983 to October 1984, the author identified a separate population of infants who presented initially with symptoms indistinguishable from those of infants who develop severe PPHN, but who responded to hyperoxia (FiO2 = 1.00) and were successfully managed with supplemental oxygen without the need for intubation, hyperventilation, or muscle relaxation to achieve hypocarbic alkalosis and adequate oxygenation. We studied 20 infants, 15 with evidence of perinatal aspiration syndromes, and compared their initial responses to supplemental oxygen with those of 16 infants whose pulmonary hypertension was severe enough to require intubation, hyperventilation, and muscle relaxation for adequate control of oxygenation. No significant differences were noted in PaO2 response in FiO2 = 0.21 or 0.40. A significant rise in PaO2 was observed among infants with transient pulmonary vascular lability (TPVL), a milder form of pulmonary hypertension of the newborn, but not among infants with persistent pulmonary hypertension of the newborn, when exposed to FiO2 = 1.00 (250.7 torr versus 86.0 torr; P less than 0.0001). No significant differences in pH or PCO2 were observed. TPVL appears to present among term or post-term large-for-gestational age (LGA) infants, frequently delivered by cesarean section, who have experienced perinatal factors known to be associated with an increased risk of PPHN.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Pediatric Department, Naval Hospital, Portsmouth, Virginia 23708-5000.
authors.forename: B W
authors.initials: BW
authors.lastname: Bonta
mesh_terms: D005865:Gestational Age; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D007442:Intubation, Intratracheal; D008991:Monitoring, Physiologic; D009466:Neuromuscular Blocking Agents / Q000627:therapeutic use; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy; D010547:Persistent Fetal Circulation Syndrome / Q000503:physiopathology / Q000628:therapy*; D011652:Pulmonary Circulation; D012121:Respiration, Artificial; D012307:Risk Factors; D013921:Thrombocytopenia / Q000209:etiology
chemical_list: D009466:Neuromuscular Blocking Agents; D010100:Oxygen