Inhaled nitric oxide monitoring.
Recently, inhaled nitric oxide (NO) became clinically available for the treatment of persistent pulmonary hypertension of the newborn. Such use requires administration and continuous monitoring of a very low concentration of NO to prevent potential toxicity. Since limited data on the reliability of NO monitoring devices are available, we evaluated the performance of a chemiluminescent and electrochemical sensor NO analyzer in a patient ventilator circuit.


RESULTS
The chemiluminescence analyzer readings were significantly altered by the oxygen concentration in the ventilator circuit. When the FiO2 was increased from 0.21 to 1, a 4.5% +/- 0.3 decrease in the NO readings was found (p < 0.01). Similarly, adding humidity to the circuit, reduced the NO readings by 4.8% +/- 0.9 (p < 0.01). The effect of gas pressure was proportional to its magnitude but independent of whether a pulsatile or continuous gas flow was provided. At a mean airway pressure of 15 cm H2O, the NO readings increased by 3.94% +/- 0.05 (NO = 10 parts per million) and 3.97% +/- 0.02 (40 parts per million) (p < 0.01). The electrochemical sensor NO readings were directly proportional to the ventilator circuit pressure but independent of whether a pulsatile or continuous gas flow was provided. At a mean airway pressure of 15 cm H2O, the NO reading was increased by 25.39% +/- 0.04 (NO = 40 parts per million) (p < 0.01) and 1.07% +/- 0.16 (NO = 10 parts per million) (p NS). The greatest difference with NO = 10 parts per million from baseline was found at a mean airway pressure of 6 cm H2O (6.67% +/- 0.23; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Fajardo
C A
CA
Department of Pediatrics, University of Manitoba, Winnipeg.
Prokopowich
J
J
Belik
J
J
D000280:Administration, Inhalation; D016903:Drug Monitoring / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry; D006813:Humidity; D008163:Luminescent Measurements; D009569:Nitric Oxide / Q000008:administration & dosage / Q000032:analysis*; D010100:Oxygen; D012122:Ventilators, Mechanical
D009569:Nitric Oxide; D010100:Oxygen