Nitric Oxide, iNO

Reviewed by Dr David Knight
February 2001
Dose and Pharmacology Newborn Drug Protocol Index Newborn Services Home Page

Management of Nitric Oxide Administration




  1. Set up circuit. A person familiar with circuit set up is called in if necessary. Turn on NOx Box or other Nitric Oxide Monitor.  Zero the monitor.
  2. Connect silicone tubing to box. The water trap and nafion tubing need to hang below the monitor to keep moisture away from the monitor.
  3. Attach sampling line to cylinder.
  4. Set up scavenging system as shown in nitric clinical guideline.
  5. Hand bag baby while circuit is set up via ventilator and until NO levels are steady.
  6. Doctor/NS-ANP is present and turns on NO flow (200ml per minute with a ventilator gas flow of 10L/min gives around 17 parts/million).
  7. When reading on NOx Box of NO ppm is at prescribed level and stable, reconnect patient to ventilator.

Observation and Documentation

  1. Concentration of NO is adjusted and documented by Doctor/NS-ANP on ventilator chart in ppm.
  2. Nursing staff must have Neonatal IV Drug Certification to nurse a baby receiving nitric oxide.
  3. Ensure at the beginning of each shift the concentration of NO prescribed on the ventilator chart is consistent with the level showing on the NO monitor and sign as correct by the nurse.
  4. NO and NO2 levels are monitored continuously and checked and documented on the ventilator chart in ppm hourly. Upper safety level of NO determined by medical staff for each individual baby.
  5. If NO readout levels rise check that there is not a leak or loose fitting in ventilator circuit. (Ventilator pressures will be reduced and because there is less flow the NO levels rise).
  6. If NO2 levels >1ppm notify Doctor/NS-ANP. NO2 levels should not exceed 3ppm in the circuit.
  7. Methaemoglobin levels should not exceed 3%.  If these exceed this, check the amount of iNO being delivered, and check that the sampling tubing is connected in the correct place.
  8. NO monitor must be higher than the water trap and nafion drying tube to prevent water entering it and rendering it unusable.
  9. Observe water trap on the monitor line and empty PRN. If this overfills water will run back to baby.
  10. Monitor blood pressure continuously and document hourly.
  11. Circuits are not changed routinely without discussion with Doctor/NS-ANP as baby will deteriorate rapidly if NO discontinued (due to very short half life of NO).
  12. During a circuit change hand bag baby until NO and NO2 monitoring is stable (Doctor/NS-ANP present).
  13. When baby is reintubated or hand bag cap ventilator end. DO NOT TURN VENTILATOR OFF AS THE NO AND NO2 LEVELS RISE IN THE TUBING.
  14. Observe and monitor baby closely for signs of deterioration during any trial off NO (Consultant orders this to determine need for continuing NO administration).
  15. The NO gauge is checked each shift for the amount left in the cylinder. When half empty inform Nurse Manager and a replacement cylinder is ordered.


Selected References

1 Clinical response to prolonged treatment of persistent pulmonary hypertension of the newborn with low doses of inhaled nitric oxide. Kinsella JP, Neish SR, Ivy DD et al. J Pediatr 1993; 123: 103-8.
2 Inhaled nitric oxide: a selective pulmonary vasodilator for the treatment of persistent pulmonary hypertension of the newborn. Geggel RL. J Pediatr 1993; 123: 76-9.
3 Inhaled nitric oxide in persistent pulmonary hypertension of the newborn. Roberts JD, Polaner DM, Land P, Zapol WM. Lancet 1992; 340: 818-9.
4 Low dose inhalational nitric oxide in persistent pulmonary hypertension of the newborn. Lancet 1992; 340: 819-20.
5 National Women’s Nitric Oxide Information Protocol Newborn Services Unit Review, 15 September 1996.