This briefing describes the regulated use of the technology for the indication specified, in the setting described, and with any other specific equipment referred to. It is the responsibility of healthcare professionals to check the regulatory status of any intended use of the technology in other indications and settings.
The RhinoChill system was CE marked for post-mark clinical investigations in December 2007 and for commercial use in April 2011. At the time of publication of this briefing, the manufacturer has also released other CE-marked devices for use with the RhinoChill system – an MRI-compatible catheter, and a low flow adapter for maintenance cooling (for post-market clinical investigations only). Each of these has separate instructions for use.
The RhinoChill system is intended for starting and continuing temperature reduction in patients until systematic cooling methods can be used. General warnings in the instructions for use state that the system should be used as an adjunct to systemic temperature control systems that maintain and reverse hypothermia. The patient must have a protected airway (for example, an endotracheal tube or supraglottic device) and be sedated before intranasal cooling.
The RhinoChill system may be administered by any healthcare professional qualified by training and experience, such as physicians, nurses and paramedics, in the pre-hospital, emergency department or intensive care settings.
The RhinoChill system is a Class IIb medical device under the European Medical Devices Directive. It provides emergency therapeutic cooling by using an intranasal evaporative catheter to deliver a mist of perfluorohexane coolant and air or oxygen to the surface of the nasal cavity at ambient temperature. The coolant–gas mixture rapidly evaporates on contact with the nasal cavity, which acts as a rapid heat exchanger, cooling the base of the skull through evaporation and the brain through direct conduction at the base of the skull. When spontaneous circulation returns, the brain and body are cooled through indirect convection, because the cooled blood removes heat through normal circulation. With the RhinoChill intranasal cooling system, systemic cooling will also occur during cardiopulmonary resuscitation before return of spontaneous circulation.
The manufacturer claims that the RhinoChill system is a minimally invasive device, because the only elements of the system in contact with the patient are the proximal end of the catheter, which is inserted into the nose, and the coolant–gas mixture.
The system is intended to be compact and portable, and consists of:
A modular control unit which controls the flow of the coolant–gas mixture and monitors system status.
A sterile, single-use intranasal evaporative cooling catheter that connects to the control unit and delivers a pressurised coolant–gas mixture to the patient.
An inert liquid coolant (perfluorohexane).
The control unit is powered from an internal, rechargeable battery providing 4 hours of operation, an external 12V DC vehicle or AC mains supply. The 1 litre coolant bottle provides therapy for between 20 and 50 minutes, depending on the flow rate selected. Coolant is mixed with medical grade oxygen or breathing air from an external source or optional rear panel tank via a gas hose connected to a side panel connector. Three settings are provided for low (25 litres/min), medium (40 litres/min) and high (60 litres/min) coolant–gas delivery rates.
Once the nasal cannulae are in position, cooling can be started at the desired flow rate setting. During operation, the control unit monitors coolant bottle presence, coolant level, catheter connection, inlet gas pressure, vertical tilt angle, external power source, battery charge level and outlet gas pressure. Front panel indicators show the status of each system component, with warnings (for example, when battery or coolant levels become low) or an alarm (for example, when coolant or gas runs out) which stops gas flow until corrected.
The Resuscitation Council UK 2010 guidelines state that, for unwitnessed out-of-hospital cardiac arrest, emergency medical services personnel should provide an appropriate combination of cardiopulmonary resuscitation and cardiac defibrillation. Tracheal intubation or the use of supraglottic airway devices to provide and maintain a clear and secure airway during cardiac arrest and cardiopulmonary resuscitation are optional (Jewkes and Nolan 2010). The adult advanced life support chapter of the 2010 guidelines states, in post-resuscitation care, that the use of therapeutic hypothermia includes comatose survivors of cardiac arrest associated initially with non-shockable rhythms as well as shockable rhythms. The lower level of evidence for use after cardiac arrest from non-shockable rhythms is acknowledged (Deakin et al. 2010).
After cardiac arrest, comatose patients whose spontaneous circulation returns can be cooled to a core temperature of 32–34°C with the aim of reducing brain injury and improving neurological outcome. As soon as possible after the cardiac arrest, mild hypothermia is induced using surface techniques (for example, heat exchange cooling pads, cooling blankets, ice packs), internal techniques (for example, an endovascular cooling device) or a combination of cooling methods. Core body temperature is maintained at 32–34°C for 12–24 hours from the start of cooling and is monitored using a bladder temperature probe. Controlled re-warming is usually done over a number of hours. In addition to cooling, patients generally receive standard critical care interventions, together with intravenous sedation and muscle relaxants (to prevent shivering) (NICE interventional procedure guidance 386). These are systemic temperature control systems that induce, maintain and reverse hypothermia and do not target the brain for cooling.
A recent health technology assessment has described non-invasive head cooling methods and devices that target the brain in adults (Harris et al. 2012):
Heat loss from the upper airways by convection with gas or fluid flow or by conduction with nasal or pharyngeal balloons. The RhinoChill system is described in this category.
Heat loss through the skull by convection (fanning, hoods or caps delivering cold air or water) or by conduction (active, for example liquid cooling, or passive, for example ice, gel caps). Some of the devices also have a neck band, which, theoretically, may help cool the brain by reducing the temperature of the carotid blood supply.
The frequency of use of non-invasive head cooling methods and devices in the NHS is unknown.
A number of ambulance services in the UK currently use various methods to start the cooling process before the patient arrives at hospital, such as cold saline drips and cooling pads. However, these methods do not directly target the brain and instead rely on cooling the whole body and blood to achieve an effect.
NICE is not aware of other CE-marked devices that have a similar function to the RhinoChill system.
The list prices of the RhinoChill system components, excluding VAT, are:
Durable unit, control unit packaged with tank holder – £7595
Durable unit, control unit packaged – £7350
Consumables, coolant bottle, 1 litre – £395
Consumables, intranasal evaporative cooling catheter – £395
Mounting options, mini dock – £1100
Mounting options, docking station – £1100
Tank holder – £295
Oxygen/air hose adapter, hose, oxygen, British/BOC, 0.3 m – £110
Oxygen/air hose adapter, hose, air, British/BOC, 0.3 m – £110
There is no initial maintenance cost to start using the RhinoChill system and no calibration is needed. Ongoing maintenance costs are subject to change and are not included in the above price list. The manufacturer recommends that the control unit is serviced yearly.
The intranasal catheter and coolant bottle are single-use items. The manufacturer states that cooling with the RhinoChill system should continue until standard systemic cooling methods have been implemented in hospital. Thus the cost per patient of a pre-hospital RhinoChill treatment will vary according to the number of coolant bottles used, with additional costs arising from the capital investment in the device, running and maintenance costs. In the PRINCE randomised controlled trial (Castrén et al. 2010), the average amount of coolant used was 1100 ml, needing 2 bottles of coolant. This suggests that the average cost of consumables per RhinoChill treatment is £1440 (including VAT).
The RhinoChill system is intended to be administered before hospital admission and in hospital by any healthcare professional qualified by training and experience. In the NHS, it appears that the introduction of the RhinoChill system for out-of-hospital use would be an additional procedure, with no direct alternative. The RhinoChill system is intended for use as a precursor to systemic temperature control systems that maintain and reverse therapeutic hypothermia. The portable nature of the RhinoChill system offers the potential advantage of being able to start brain cooling and neuroprotection out of hospital rather than the current systemic cooling on arrival at hospital. The patient must have a protected airway (for example, endotracheal tube or supraglottic device) and be sedated before intranasal cooling.
Cooling during the intra-arrest or very early post-arrest period, as provided by the RhinoChill system, might be beneficial compared with later post-resuscitation (conventional) cooling.
In an emergency setting the RhinoChill system was effective at reducing temperature and although there is limited UK clinical experience with the RhinoChill system, no complications have been identified.
The system has the advantage that it is compact and portable, and, unlike other cooling methods, can feasibly be used in a pre-hospital setting.