Applications

nHFV. Nasal high frequency ventilation

Medijet

High-frequency and nCPAP

nHFV combines the benefits of high-frequency ventilation and non-invasive CPAP support (De Luca D, Dell'Orto V. Non-invasive high-frequency oscillatory ventilation in neonates: review of physiology, biology and clinical data. Arch Dis Child Fetal Neonatal Ed. 2016;101(6):F565-F570. doi:10.1136/archdischild-2016-3106641). 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.

  • 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

Rescue therapy

The carbon dioxide elimination takes place in the upper airway in the form of a washout effect (De Luca D, Dell'Orto V. Non-invasive high-frequency oscillatory ventilation in neonates: review of physiology, biology and clinical data. Arch Dis Child Fetal Neonatal Ed. 2016;101(6):F565-F570. doi:10.1136/archdischild-2016-3106641). 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 D, Dell'Orto V. Non-invasive high-frequency oscillatory ventilation in neonates: review of physiology, biology and clinical data. Arch Dis Child Fetal Neonatal Ed. 2016;101(6):F565-F570. doi:10.1136/archdischild-2016-3106641):

  • Increased carbon dioxide values which do not require ventilation
  • Apnea-bradycardia syndrome
  • Stabilization of the airways
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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 (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;52(8):1038-1042. doi:10.1002/ppul.237552​, Chen W, Chen Z, Lai S, Cai W, Lin Y. Noninvasive high-frequency oscillatory ventilation versus bi-level positive pressure ventilation in premature infants with respiratory failure: A retrospective study. Pak J Med Sci. 2022;38(5):1353-1359. doi:10.12669/pjms.38.5.59393​)

The higher the frequency, the lower the pressure amplitude.

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 D, Dell'Orto V. Non-invasive high-frequency oscillatory ventilation in neonates: review of physiology, biology and clinical data. Arch Dis Child Fetal Neonatal Ed. 2016;101(6):F565-F570. doi:10.1136/archdischild-2016-3106641).

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

Non-invasive high-frequency oscillatory ventilation in neonates: review of physiology, biology and clinical data

De Luca D, Dell'Orto V. Non-invasive high-frequency oscillatory ventilation in neonates: review of physiology, biology and clinical data. Arch Dis Child Fetal Neonatal Ed. 2016;101(6):F565-F570. doi:10.1136/archdischild-2016-310664

Non-invasive high-frequency oscillatory ventilation (NHFOV) consists of the application of a bias flow generating a continuous distending positive pressure with superimposed oscillations, which have constant frequency and active expiratory phase. NHFOV matches together the advantages of high-frequency ventilation (no need for synchronisation, high efficacy in removing CO2) and nasal continuous positive airway pressure (CPAP) (non-invasive interface, increase in functional residual capacity allowing oxygenation to improve). There is enough clinical expertise demonstrating that NHFOV may be tried in some selected cases, in whom CPAP or conventional non-invasive ventilation have failed. Nonetheless, there are no clear data about its clinical usefulness and there is a need for randomised controlled studies. Our purpose is to review the physiology and biological effects of NHFOV, to present the current clinical evidence on its use, to provide some guiding principles to clinicians and suggest directions for further research.

Noninvasive high-frequency oscillatory ventilation versus nasal continuous positive airway pressure in preterm infants with moderate-severe respiratory distress syndrome: A preliminary report.

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;52(8):1038-1042. doi:10.1002/ppul.23755



OBJECTIVE

The aim of this study was to compare the effect of noninvasive high-frequency oscillatory ventilation (nHFOV) with nasal continuous positive airway pressure (nCPAP) in preterm infants with moderate-severe respiratory distress syndrome (RDS) after surfactant administration via INSURE (intubation, surfactant, extubation) method on the need for invasive mechanical ventilation (IMV).

METHODS

A total of 81 infants with a gestational age (GA) of 28-34 weeks were eligible and were randomized to nCPAP (n = 42) or to nHFOV (n = 39). The need for IMV was the primary outcome. The incidence of bronchopulmonary dysplasia (BPD), occurrence of intraventricular hemorrhage (IVH), and air leaks, and mortality were considered as secondary outcomes.

RESULT

A total 76 infants finally completed the study. The need for IMV was significantlylower in the nHFOV group compared with the nCPAP group(24.3% vs 56.4%, P < 0.01). The incidence of IVH, air leaks or BPD was similar between the two groups. In addition, the mortality rate was not statistically different.

CONCLUSION

In this prospective, randomized controlled study, nHFOV significantly reduced the need for IMV as compared with nCPAP in preterm infants with moderate-severe RDS without increase in adverse effects.

Noninvasive high-frequency oscillatory ventilation versus bi-level positive pressure ventilation in premature infants with respiratory failure: A retrospective study.

Chen W, Chen Z, Lai S, Cai W, Lin Y. Noninvasive high-frequency oscillatory ventilation versus bi-level positive pressure ventilation in premature infants with respiratory failure: A retrospective study. Pak J Med Sci. 2022;38(5):1353-1359. doi:10.12669/pjms.38.5.5939



OBJECTIVES

Noninvasive high-frequency oscillatory ventilation (nHFOV) is a novel respiratory support mode for premature infants. This retrospective study aimed to compare the effect of nHFOV and bi-level nasal continuous positive airway pressure (BiPAP) in premature infants with neonatal respiratory failure (NRF) as initial noninvasive ventilation (NIV) support mode.

METHODS

We retrospectively analyzed medical records of preterm infants admitted to the tertiary neonatal intensive care units (NICUs) of Fujian Maternal and Child Health Hospital from January 2019 to December 2020. Preterm infants with the gestational age of 25-34 weeks, diagnosed with NRF, used nHFOV or BiPAP as the initial respiratory support mode were analyzed. The rates of invasive mechanical ventilation (IMV) within the first seven days after birth and adverse outcomes were compared between the two groups.

RESULTS

Two hundred fifty-five preterm infants were analyzed (128 in nHFOV group,127 in BiPAP group). There was no significant difference in baseline characteristics between the two groups. Compared with the BiPAP group, the nHFOV group had significantly lower need for IMV within the first seven days after birth (18/128 vs. 33/127, p = 0.01) and PCO2 at 12 and 24 hours post-treatment (46.34±5.24mmHg vs. 51.18±4.83mmHg, P<0.01; 40.72±4.02mmHg vs. 42.50±3.86mmHg, P<0.01). The incidence of BPD, ROP, air leak syndromes, IVH≥ grade 3, PVL, NEC≥II stage, abdominal distension, and nasal trauma were similar between the two groups.

CONCLUSION

nHFOV significantly reduced the need for IMV and improved the elimination of CO2 compared with BiPAP in preterm infants with NRF without increasing the incidence of adverse effects.