The Journal of Pediatrics
`Volume 129. Number 1
`
`Editorial correspondence
`
`1 8 3
`
`lnholed nitric oxide con cause
`
`Neurodevelopmentol outcome in
`
`severe systemic hypotension
`To the Editor.-
`Inhaled nitric oxide (NO) is a promising and now widely used
`pulmonary vasodilator for neonates with persistent pulmonary
`hypertension of the newborn (PPHN) because of its alleged lack
`of systemic hypotensive side effects.‘ We describe a term baby
`with PPHN and left ventricular dysfunction caused by birth
`asphyxia, in whom marked systemic hypotension developed after
`exposure to NO. The condition reversed when NO therapy was dis-
`continued.
`
`The baby, born at 38 weeks of gestation, was referred to our in-
`sfimtion at 5 hours of age for cardiac assessment to exclude cyan-
`otic heart disease. An cchocardiogram showed a structurally normal
`heart, severe left ventricular dysfunction. and a patent duclus arte-
`riosus (PDA) with bidirectional flow. This suggested that the sys-
`temic perfusion was dependent on the right-to-left shunt through the
`PDA. and therefore the prostaglandin E2 infusion, started at the re-
`ferring hospital, was continued to maintain ductal potency. A dob-
`utaminc infusion was commenced to provide inotropic support to
`the left ventricle.
`
`The baby was given 2: trial of NO 6 hours later because of wors-
`ening hypoxemia. (sanitation of arterial oxygen interrnittentiy fall-
`ing to 50%). Exposure to N0 (20 ppm) resulted in an imnrediatc fall
`in the mean systemic arterial blood pressure from 48 to 35 mm Hg,
`which reversed when NO therapy was discontinued. This hypoten-
`sive episode was thought to have been caused by the 1"~l(J’s rovers-
`ing the right—to-left shunt mrough the PDA on which the systemic
`circulation depended.
`Thirty hours later, after recovery of left ventricular function
`(clinically and on echocardiography}, a second trial of NO (20 ppm
`for 30 minutes) resulted in a marked improvement in oxygenation,
`from an arterial oxygen tension of 16 to 420 mm Hg without a
`change in the systemic arterial blood pressure. The baby was suc-
`cessfully weaned from NC! during a period of 30 hours, and exto-
`bation was successful 2 days later.
`This case demonstrates that aldrough N0 is a selective pulmonary
`vasodilator, it can nonetheless cause severe systemic hypotension
`in babies with PPI-IN associated with severe left ventricular
`
`dysfunction. 510 should therefore be administered with caution to
`such babies.
`
`There Henrichsen, Cami Med
`Allan P. Goldman, MRCP
`Duncan J. Macrue, FRCA
`Cardiac Intensive Care Unit,
`Great Omwrid Street Hospital for Children NHS Tmst
`London WCIN 31H, United Kingdom
`9l35f733l4
`
`extrocorporeol membrane
`
`oxygenation survivors
`To the Editor:
`
`The long-term outcome for critically ill neonates requiring extra-
`corporeal membrane oxygenation (ECMO) reflects not only the in-
`herent risk of the procedure but also the underlying disease state.
`the aggressive conventional therapy required, and the child’s fam-
`ilyfhorne environment. The recent article by Glass et al.' has been
`helpful in delineating the 5—year neurodeveloprnental outcome for
`ECMO-treated stuvivors. However, these 103 ECMCHreated sub-
`jects include 6l% of discharged survivors, leaving an almost 40%
`of loss-to—follow-up rate, particularly among those requiring
`extended travel, and hence raising the possibility of selection bias
`along urbanlrural or nearfdistant lines. Comparison subjects num-
`bered less than one third of study subjects and were not adequately
`matched for a case-control study; notably they had a significantly
`longer gestation with a narrower standard deviation, suggesting that
`the ECMO-treated children had a greater range of gestational age.
`This is particularly important because the authors previously sug-
`gested a possible association between gestational age and outcome?
`Nonetheless, me report of 42% of nonretarded ECMO~I:reated chil-
`diet! at risk of school failure is clinically very important.‘ The pro-
`portion of reported behavioral concern in this Washington popula-
`tion is high and requires further evaluation. In view of recent reports
`of undetected neurosensory hearing loss after infancy in both
`ECMO survivors and children with persistent pulmonary hyperten-
`sion?" ‘ and the link of undetected hearing loss with poor [‘1E.ll1‘0l3€-
`havioral performance and school failure, further evaluation of
`childhood heu.ri.ng should be carried out in this population.
`We ask the authors of this article, if at all possible, to reanalyze
`Lhei.1' data for the ECMO—trea1ed study group, using familyfhome
`environment and underlying respiratory diagrrosnc variables to
`predict the risk of academic failure. l.n view of the complexity of
`insults of ECMO-treated survivors, it is strongly recommended that
`subsequent comparisons use a comparable “control" group of crit-
`ically ill infants not treated with ECMO to assess the safety and ef-
`fectiveness of ECMO therapy. Because most nontrcatcd ECMO
`candidalzcs do not survive, the choice of control groups is not ideal;
`however,
`those with documented hypoxemia are preferable to
`healthy children as control subjects.
`Po-Yin Chew-lg, MBB.£ MRCHUK), DCH
`Charlene M.
`It’. Robertson. MD, FRCP{Cj
`Neonatal Fot'Low—up Clinic.
`Glemvse Rehabilitation Hospital.
`University ofAlbern:1
`Edmonton, Alberta, Canada
`9i35:"73300
`
`REFERENCE
`
`REFERENCES
`
`1. Kinsella IF, Neish SR, Ivy DD, Shaffer E, Abman SH. Clin-
`ical responses to prolonged treatment of persistent pulmonary
`hypertension of the newborn with low doses of inhaled nitric
`oxide. 1 Pediatr 1993;123:103-8.
`
`1. Glass P, Wagner AE, Papero PH, ct Ill. Neurodevelopmental
`status at age five years of neonates heated with extracorporeal
`membrane oxygenation. I Pediatr l995;127:447—5'1'.
`2. Glass P, Miller M, Shon. B. Morbidity for .‘i1IJ’\«'i\«'0l'S of extra-
`
`Mallinckrodt Hosp. Prods. IP Ltd.
`Exhibit 2041
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