Inhaled nitric oxide and persistent pulmonary hypertension of the newborn. The Inhaled Nitric Oxide Study Group.
BACKGROUND
Persistent pulmonary hypertension of the newborn causes systemic arterial hypoxemia because of increased pulmonary vascular resistance and right-to-left shunting of deoxygenated blood. Inhaled nitric oxide decreases pulmonary vascular resistance in newborns. We studied whether inhaled nitric oxide decreases severe hypoxemia in infants with persistent pulmonary hypertension.


METHODS
In a prospective, multicenter study, 58 full-term infants with severe hypoxemia and persistent pulmonary hypertension were randomly assigned to breathe either a control gas (nitrogen) or nitric oxide (80 parts per million), mixed with oxygen from a ventilator. If oxygenation increased after 20 minutes and systemic blood pressure did not decrease, the treatment was considered successful and was continued at lower concentrations. Otherwise, it was discontinued and alternative therapies, including extracorporeal membrane oxygenation, were used.


RESULTS
Inhaled nitric oxide successfully doubled systemic oxygenation in 16 of 30 infants (53 percent), whereas conventional therapy without inhaled nitric oxide increased oxygenation in only 2 of 28 infants (7 percent). Long-term therapy with inhaled nitric oxide sustained systemic oxygenation in 75 percent of the infants who had initial improvement. Extracorporeal membrane oxygenation was required in 71 percent of the control group and 40 percent of the nitric oxide group (P=0.02). The number of deaths was similar in the two groups. Inhaled nitric oxide did not cause systemic hypotension or increase methemoglobin levels.


CONCLUSIONS
Inhaled nitric oxide improves systemic oxygenation in infants with persistent pulmonary hypertension and may reduce the need for more invasive treatments.
Roberts
J D
JD
Department of Anesthesia, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
Fineman
J R
JR
Morin
F C
FC
Shaul
P W
PW
Rimar
S
S
Schreiber
M D
MD
Polin
R A
RA
Zwass
M S
MS
Zayek
M M
MM
Gross
I
I
Heymann
M A
MA
Zapol
W M
WM
D000280:Administration, Inhalation; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000188:drug therapy* / Q000209:etiology; D007231:Infant, Newborn; D008297:Male; D008708:Methemoglobinemia / Q000139:chemically induced; D009569:Nitric Oxide / Q000009:adverse effects / Q000627:therapeutic use*; D010547:Persistent Fetal Circulation Syndrome / Q000150:complications / Q000188:drug therapy*; D011446:Prospective Studies; D016896:Treatment Outcome
D009569:Nitric Oxide