WO2002058773A1

WO2002058773A1 - Anaesthesia apparatus and gear

Info

Publication number: WO2002058773A1
Application number: PCT/NO2002/000008
Authority: WO
Inventors: Erik Helmich Pedersen
Original assignee: Erik Helmich Pedersen
Priority date: 2001-01-09
Filing date: 2002-01-08
Publication date: 2002-08-01
Also published as: NO20010158L; NO313406B1; NO20010158D0

Abstract

An anaesthesia apparatus or anaesthesia equipment, comprising a filter unit (1) arranged to be connected at the one end to a mask or intubation tube and at the other end to a Y-piece or similar branch connection (2) with a tube (31) for supplying gas to the patient and a tube (32) for extraction of gas from the patient, in which there at the patient's end of the branch connection (2), preferably at the patient's end of the filter unit (1) and preferably as a separate unit, is arranged a closing valve (5) which can be closed when the connection from the equipment is to be changed from mask to intubation tube.

Description

ANAESTHESIA APPARATUS AND GEAR

The present invention concerns an arrangement for anaesthesia apparatus or anaesthesia equipment. Anaesthetic gases have been used for many years. It is a known fact that when anaesthetic gases escape, it causes an increase in the occurrence of miscarriages and congenital defects in children whose mothers have been exposed to anaesthetic gases over time, as a result of their work as anaesthesia staff. New extractors and better ventilation systems have reduced the number of leaks and thus the gas concentration in the operating theatre. This is particularly so in cases where the anaesthetic gas is applied after the patient is placed under general anaesthetic by other means. Today anaesthetic gases are used primarily to maintain a general anaesthetic, whilst other means are used to initiate a general anaesthetic. At least one of the anaesthetic gases used today however, is also very suitable to initiate a general anaesthetic. However, one prefers usually not to use the gas to initiate the general anaesthetic, because with today's equipment this causes undesired gas leakage when changing from the first stage with a mask to intubation. Changing from a mask to intubation tube can take between 1 and 3 minutes to complete, and during this time gas will escape into the opera- ting theatre. The present invention concerns an arrangement by which this undesired emission can be prevented.

In anaesthesia apparatus the gases move in a "circle". Oxygen, laughing gas and air can be added to the system by so-called "rotameters", while pure anaesthetic gases are added to the system by so-called "evaporators". A tube is placed in the patient's respiratory passage, and the system behaves as a closed system or a circular system. Outside the patient the gases pass through a tank for removing carbon dioxide from the gases, so that the amount of gas used is reduced. Some of the gas goes to extraction, to prevent the anaesthesia staff from being exposed over time to harmful anaesthetic gases, while new gas - a small, suitable amount - is added to the system before the gases once again are administered to the patient. Even with such extraction, it is not possible to prevent or eliminate all gas leaks. When a gas general anaesthetic is initiated on a patient, a mask, connected to an anaesthetic system is placed over the patient's nose and mouth, after which oxygen and initial general anaesthetic gas is supplied, until the patient is in a sufficiently deep state of unconsciousness that intubation can take place to maintain the general anaesthesia. During this procedure, which can take several minutes, gas will escape into the room.

An anaesthesia system comprising a so-called APL valve, arranged in the extraction line from the system, is already known from US Patent No. 5566669. The APL valve - or a corresponding arrangement - is commonly used in all modern anaesthesia apparatus and serves to adjust the gas pressure in the system to the lowest gas pressure possible to exceed the pressure in the patient's respiratory passage. When the APL valve is fully open, gases, including the patient's exhaled breath, pass directly into the extractor instead of in the patient's respiratory passage, whilst the gas pressure will more or less prevent the patient from exhaling when the APL valve is closed. The APL valve, or corresponding arrangement in the extractor from the anaesthesia apparatus will not, however, prevent the anaesthetic gases from escaping into the operating theatre in the above- mentioned procedure when changing from the introductory stage to intubated anaesthesia.

The invention is thus concerned with an arrangement for anaesthesia apparatus or anaesthesia equipment. The apparatus or equipment comprises, starting from the patient's end, a filter unit designed to be connected at the one end directly to a mask or intubation tube and at the other end to a Y-piece or similar branch connection with a tube for supplying gas to the patient or a tube for extraction of gas from the patient. The distinctive feature with the arrangement in accordance with the invention is that at the patient's end of the branch connection, ie. between the branch connection and the filter unit or at the patient's end of the filter unit, a closing valve is placed, which can be activated when the connection from the equipment is to be changed from mask to intubation tube. The closing valve can be constructed together with the branch connection or together with the filter unit, but it is considered advantageous, especially since the filter unit is designed to be disposed/destroyed after single use, for the valve to be de- signed as a separate unit which can be used several times.

The invention will now be described with reference to the enclosed drawing which, very schematically, shows an anaesthesia apparatus with a closing valve in accordance with the invention. The drawing shows an anaesthesia apparatus or anaesthesia equipment, comprising a filter unit 1 which is designed to be connected at the one end directly to a mask or intubation tube and on the other side to a Y-piece or a similar branch connection 2 with one tube 31 for supplying gas to the patient and one tube 32 for extraction of gas from the patient. The other ends of the two tubes 31 and 32 are connected to the normal anaesthesia apparatus 4, shown in the diagram as a box, with a unit for controlled supply of different desired gases, a unit for cleaning and separating exhaled gases, which are supplied through the extractor tube 32, a bellow unit for assisting respiration, and other units normally occurring in usual anaesthesia apparatus.

In anaesthesia apparatus or equipment available today the branch connection 2 is connected directly to the filter unit 1 which in turn is directly connected to the anaesthesia mask (not shown) or to the intubation tube (again, not shown), as the mask is used as a start for the initial anaesthesia whilst the intu- bation tube is used for the "maintaining anaesthesia". When the apparatus is to be re-connected from the mask to the intubation tube, the anaesthetic gas will continue to flow out from the temporarily open tube end to the mask, respectively intubation tube, which can lead to congenital defects in children of the staff exposed to such gas emission over a length of time, i.e. for example anaesthesia staff or operation staff.

To avoid such leakages with resulting risk of damage, there is in accordance with the present invention an easily manoeuvrable closing valve 5 on the patient's side of the branch connection 2, preferably (as shown) on the patient's side of the filter unit 1 , but an arrangement between the branch connection 2 and the filter unit 1 can also be used. An arrangement of the closing valve 5 together with the filter unit 1 is not considered very favourable since the filter unit, for reasons of hygiene and cost is usually designed to be disposed/destroyed after single use. The arrangement of the closing valve 5 together with the branch connection 2, however, is not excluded. The single units in the system can, in the usual way, be attached by help of slightly conical ends, which work with corresponding ends on adjacent units. Reference 6 depicts the joining ends on a mask or an intubation tube.

Claims

PATENT CLAIMS

1. An arrangement for an anaesthesia apparatus or anaesthesia equipment, comprising a filter unit (1) designed to be connected at the one end to a mask or intubation tube and at the other end to a Y-piece or similar branch connection (2) with a tube (31) for supplying gas to the patient and a tube (32) for extracting gas from the patient, characterized by that there at the patient's end of the branch connec- tion (2) is placed a closing valve (5) which can be activated when the connection from the equipment is to be changed from mask to intubation tube.

2. An arrangement as described in claim 1 , characterized by that the closing valve (5) is placed at the patient's end of the filter unit (1).

3. An arrangement as described in claims 1 or 2, characterized by that the closing valve (5) is designed as a separate unit.