Nasal high frequency ventilation

  • Effective CO2 washout
  • No synchronization needed
  • Combination of HFV and nasal interface
  • Ideal supplement to conventional non-invasive respiratory support
  • Available in the medinCNO device®

nHFV combines the benefits of high-frequency ventilation and non-invasive CPAP support (De Luca D, 2016). The patient breathes spontaneously with CPAP support. A special valve shifts the air flow in all phases of spontaneous respiration under high-frequency oscillations (<200 BPM).  

The benefits of CPAP thus include the pronounced ventilatory effect of the high-frequency ventilation. While peak pressures and target volume changes are used with conventional modes such as NIPPV in order to eliminate carbon dioxide, this effect is achieved in nHFV through the high-frequency oscillations. The patient is not exposed to any fixed breaths. In addition, no synchronization is necessary.

The carbon dioxide elimination takes place in the upper airway in the form of a washout effect (De Luca 2016). nHFV is frequently used as rescue therapy to prevent intubation. Especially when modes such as NIPPV/SNIPPV do not bring about the desired success.

However, nHFV is also increasingly being used as primary respiratory support since it is an ideal complement to conventional non-invasive respiratory support.

Positive effect in apnea-bradycardia syndrome

In addition to the effective carbon dioxide washout, nHFV can stabilize the airways and thus has a positive effect in apnea-bradycardia syndrome.

The indications for nHFV are (De Luca 2016):

  • Increased carbon dioxide values which do not require ventilation
  • Apnea-bradycardia syndrome
  • Stabilization of the airways

medinCNO and nHFV

The medinCNO is the only CPAP device worldwide which can offer you nasal high-frequency ventilation. In combination with conventional modes such as nCPAP, ApneaCPAP, SNIPPV and NIPPV, nHFV in the medinCNO is an effective instrument for individually adapting the non-invasive respiratory support to the patient.

The efficacy with regard to avoiding intubation, CO2 washout as well as positive effects on circulation were able to be demonstrated in studies (Ruolo, Zhu XW 2017)

First adjust the optimal CPAP pressure for the patient with regard to oxygenation and breathing effort. With a so-called flow interruptor valve, the breathing gas flow is shifted in the device under high-frequency oscillations. Depending on how far the valve closes, the resultant amplitude is defined with regard to its height. Frequencies are to be set from 300 to 1200 BPM.

The following applies: The higher the frequency, the lower the pressure amplitude. That is, the efficacy with regard to CO2 washout decreases with increasing frequency. A frequency value of 10 Hz is established as an initial setting which must subsequently be individually adjusted to the patient.

Vibration of the upper airway should be sought; by contrast, vibration of the chest is not necessarily needed. The force of the nHFV should not be compared with that of invasive HFV. Leakages, especially via the mouth, and upper airway compliance can suppress the nHFV amplitude (De Luca 2016).

The following parameters are to be set

  • Basic flow: In L/min; generates the CPAP/PEEP in the Medijet nCPAP generator
  • Push flow: In L/min; generates a second pressure level, PIP, in the Medijet nCPAP generator, in addition to the basic flow
  • Amplitude: In increments of 1 to 10; defines the level of the pressure amplitude via the depth of closure of the high-frequency valve; level 10 = highest amplitude; level 1 = lowest amplitude
  • Frequency: In Hz; defines the number of closures of the high-frequency valve per
  • oxygen supply

References

De Luca D, Dell’Orto V. Arch Dis Child Fetal Neonatal Ed 2016; 0:F1–F6. doi:10.1136/archdischild-2016-310664

RUOLO DELL’N-HFOV SULLA FUNZIONALITÀ VENTRICOLARE DESTRA IN PRETERMINE ELBW V. Fatuzzo1, C. Mattia1, A. Lanzafame1, A. Castro 1, P. Sciacca1, M. Caracciolo1, S. Cilauro1, M.A. Conversano 1, M. Marletta1, A. Saporito1, P. Betta1 1UOC UTIN-Neonatologia, AOU Policlinico Vittorio Emanuele, Catania

Zhu XW, Zhao JN, Tang SF, Yan J, Shi Y; Noninvasive high-frequency oscillatory ventilation versus nasal continuous positive airway pressure in preterm infants with moderate-severe respiratory distress syndrome: A preliminary report. Pediatr Pulmonol. 2017 Aug;52(8):1038-1042. doi: 10.1002/ppul.23755. Epub 2017 Jul 3.