Delivery and monitoring of inhaled nitric oxide in patients with pulmonary hypertension.
OBJECTIVE
The development of a safe, portable, accurate, and adaptable system to deliver nitric oxide to patients with pulmonary hypertension.


METHODS
A prospective, clinical study.


METHODS
Tertiary care pediatric intensive care unit and cardiac catheterization laboratory.


METHODS
One hundred twenty-three patients (median age 11 months, range 1 day to 72 yrs) with pulmonary hypertension who were administered nitric oxide between November 1991 and July 1993. Ninety-one patients were mechanically ventilated (volume-controlled ventilator, n = 53; pressure-controlled ventilator, n = 5; and a pressure-limited, time-cycled infant ventilator, n = 25). The system was adapted to allow high-frequency oscillator (n = 2) or hand ventilation, and for intraoperative use with an anesthesia machine (n = 6). Thirty-two patients were breathing spontaneously through a mask without assistance.


METHODS
Nitric oxide was delivered at 10 to 80 parts per million (ppm); the dose was adjusted independently of the FIO2 without altering minute ventilation or tidal volume.


RESULTS
Nitrogen dioxide was continuously monitored and exceeded 3 ppm in only four patients. Methemoglobin concentrations were < 5% in all but four patients. Nitric oxide doses remained stable, independent of minute ventilation and could be changed easily and quickly.


CONCLUSIONS
Inhaled nitric oxide can be administered precisely and reliably through a variety of delivery systems which can be used in patients of any size. Potential toxicity requires careful monitoring and continued improvement on apparatus design.
Wessel
D L
DL
Cardiac Intensive Care Unit, Children's Hospital, Boston, MA 02115.
Adatia
I
I
Thompson
J E
JE
Hickey
P R
PR
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods; D016903:Drug Monitoring / Q000295:instrumentation / Q000379:methods; D006801:Humans; D006976:Hypertension, Pulmonary / Q000628:therapy*; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D009569:Nitric Oxide / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D012121:Respiration, Artificial
D009569:Nitric Oxide