The technology

The focus of this briefing is the Servo‑n pneumatic life-support system with Neurally Adjusted Ventilatory Assist (NAVA) technology (Getinge Group). It is for babies and children who need ventilator assistance. NAVA consists of proprietary software and a bespoke oesophageal catheter that serves as a feeding tube. It contains small sensors, designed to measure the diaphragm electrical activity (the Edi measurement). This information is used to interpret the neural respiratory drive to control the timing and amount of ventilatory assistance provided. The Edi measurement can also be used for continuous bedside monitoring of a baby or child's breathing effort. NAVA mode is available for babies or children having invasive or non‑invasive mechanical ventilation. In babies or children having non‑invasive ventilation, the Edi is measured in the same way. But ventilation is provided by either nasal prongs or a nasal mask.

The NAVA technology can only be used with a compatible Servo‑n ventilator.


NAVA differs from standard ventilator systems because it uses electrical changes in the diaphragm muscle to control the timing of ventilation. This is designed to provide more accurate synchronisation with the patient's respiratory drive, minimising the risk that happens substantially earlier in the process of breathing. Conventional ventilator systems use pressure or flow signals, which are affected by air leaks, to trigger support and which may result in asynchronous ventilation.

Current care pathway

No national guidelines that cover the NAVA technology for neonatal ventilation were identified. The common indication for ventilation in babies is either 1, or a combination of the following:

  • parenchymal lung disease or ventilation perfusion mismatch (for example, meconium aspiration, pneumonia)

  • poor respiratory drive (for example, hypoxic–ischemic encephalopathy, sepsis)

  • lung malformations (for example, diaphragmatic hernia, congenital cystic adenomatoid malformation)

  • mechanical (for example, abdominal distension, airway obstruction).

Population, setting and intended user

The Servo‑n with NAVA would be used in babies and children weighing between 0.3 and 30 kg who need mechanical ventilation (invasive or non‑invasive). It would be used in place of conventional ventilator systems in paediatric or neonatal intensive care units. The place in therapy is currently uncertain as to which patient groups would benefit most from the technology. Servo‑n with NAVA would be used by multi-disciplinary teams.


Technology costs

The list price of a Servo‑n ventilator is about £28,000 (excluding VAT), with an annual maintenance or service schedule negotiable within the price. The anticipated life span of the ventilator is 7 to 10 years. An additional NAVA module is needed, at a cost of around £6,300 (also excluding VAT). The list price of the single-use NAVA catheter, which is certified for 5 days' use, is £145.

Existing Servo‑i ventilators can be upgraded with software and an additional module. The list prices of these are: Edi-module around £6,300; NAVA software around £2,000 and NIV NAVA software around £1,300 (all list prices are excluding VAT).

Costs of standard care

Standard care would be a ventilator machine without the NAVA technology, which is estimated by specialist commentators to cost around £25,000. Conventional ventilators need tubing to connect the patient with the ventilator. These are typically single use and vary widely in cost.

Resource consequences

The use of NAVA would be an additional cost compared with standard care. Staff would need additional training and the company has stated that training and initial support costs are included in the purchase price. If NAVA reduced the time to discharge from an intensive care unit, then the additional costs may be offset. But there is no published evidence to support this. The NAVA catheter is ENFit compatible and is managed in the same way as a conventional feeding tube.