PORTABLE SUCTION APPARATUS

Abstract: The invention provides a portable device for the collection of thoracic fluid comprising a collection chamber (1) having an inlet (16) for connection to a patient, a one way valve (11) that permits passage of thoracic fluid from the patient to the collection chamber (1) through the inlet (16) and a portable suction unit (21) that co-operates with the collection chamber (1) for evacuation of air therefrom. Preferably the one way valve (11), the inlet (16) and the connection of the chamber (1) are disposed on a removable lid of the chamber (1). The collection chamber (1) and suction unit (21) are of a size and weight that allow them to be carried by a patient.

Description: PORTABLE SUCTION APPARATUS. The invention relates to drainage of air and fluid from the thoracic cavity after thoracic surgery. In this field it is already known that conventional chest drainage systems used after thoracic surgery achieve a seal or one way valve to prevent air and fluid returning to the chest via an underwater seal. Typically a 2ltr rigid container is used for collection, water is poured into the container and a straw which connects to a tube set is placed with its tip below the level of the water to achieve an underwater seal. Disadvantages with conventional underwater seal drainage systems include: a) they are cumbersome and therefore limit patient mobility with inherent postoperative risks, b) they must be kept upright to prevetn displacement of the drained fluid and distruption of the underwater valve mechanism, c) fluid accumulation in the drainage tubing can increase the opening pressure required for drainage and therefore reduce the ffectiveness of the system, and d) when suction drainage is required this necessitates continuous connection to a fixed suction unit and further reduces patient mobility. An alternative flutter valve drainage system (Portex Ltd) has beens hown to have several advantages over the underwater seal system. This uses a bag with a flat valve with straps pulled across a patient's chest. The flutter valve drainage bag was found to be safe and effective in the post-operative situation and permitted earlier mobility. Also, the system maintains a more negative intrapleural pressure during tidal respiration without suction. The flutter valve drainage bag does however have some disadvantages in that suction cannot be applied to the collapsible bag and therefore the bag cannot always be used immediately after surgery. Patients are therefore immobilised for several days postoperatively until suction can be removed. It is an object of the present invention to provide an improved effective drainage system to allow early patient mobility after operations. According to the present invention there is provided a portable device for the collection of thoracic fluid, comprising a collection chamber having an inlet for connection to a patient, a one-way valve that permits passage of thoracic fluid from the patient to the collection chamber through the inlet, and a portable suction unit that also co-operates with the collection chamber for evacuation of air thereform. The invention uses a flutter valve rather than an underwater seal with advantages as set out about-G. Preferably the container is rigid and therefore suction can be applied. Preferably the portable suction unit is battery powered. This enables the patient to mobilise earlier. Preferably, the collection chamber and the suction unit are each of a size and weight that allow them to be carried by a patient. Preferably also, the one-way valve, the inlet and the connection of the chamber with the suction unit are disposed on a removable lid of the chamber. In a more preferred embodiment of the invention the lid of the container has at least two valves, one of which can be used for the evacuation of air from the container, the other valve allowing collection of thoracic fluid. Preferred design features are listed below. A conventional intercostal drainage tube can be connected directly to the unit. The flutter valve is already established in clinical practice. There can be a water trap just prior to the suction outlet which acts as a visual indicator of flow. A negative suction control can be used to prevent suction greater than 5KPa. A positive pressure release valve can prevent complications from system occlusion. An audible plus visual indicator of low battery power on the portable suction unit can be used. The size (500ml capacity) and wieght of the units allow to be positioned on the hip to permit complete mobiity. The invention will now be described with reference to the accompanying figures wherein: Figure 1 illustrates a device according to the invention. Figure 2 illustrates pump pressure with a conventional underwater drawin to validate pressure monitoring. Figure 3 illustrates pump pressure in the device of the invention demonstrating that suction works. Figure 4 illustrates pump pressure in the device of the invention. Example The MIS thoracic drainage bottle and portable suction unit is comprised of three elements :- i) Collection chamber - the collection chamber (1) will be available in 0.51tr and 0.251tr versions with 20ml graduations (2) . The shape of the chambers will be curved, as can be seen from Figure 1, to allow ease of placement on a patients hip. The chambers will be rigid allowing suction levels of up to -40cms H 2 0 to be applied. A clip (3) is attached to the rear of the chamber to enable a belt to be passed through it. ii) The lid section contains the working elements of the unit and is compatible with both sizes of container. The key features are : a) sealed non return valve (11) ; b) visible flow indicator (12) ; c) variable suction control (13) ; d) positive pressure release valve (14) ; e) detachable tube set (15) ; f) suction port (17) ; and g) the tube set will also have an air sample port (16) . iϋ) Portable suction unit (21) - the portable suction unit is also secured via the patient belt (4) and attached to the MIS thoracic drainage bottle via a short length of tubing. The unit is battery operated, re-chargeable, having a working cycle of 18 hours between charges. There is an operating flow rate of 2 ltrs per minute against a maximum pressure of -40cms H 2 0, with variable control for changing prescribed pressure levels. In addition there is a low battery indicator via a visible LCD, and an audible alarm. The unique combination of a small rigid thoracic drainage chamber, a non return valve/ seal with a portable suction unit allows for improved patient mobility after thoracic surgery or trauma, and the resultant clinical benefits associated with early patient mobilisation. The key elements are as follows :- i) The size and weight of the unit along with the ability to position it on a patients hip allow for improved mobility compared with the traditional 21tr drainage units. ii) If suction is applied the patient remains mobile by using the portable suction unit. The patient is conventionally confined to a bed when wall suction is applied to the traditional drainage units, and if a drainage bag is being used it will have to be removed and replaced with a rigid unit, before wall suction can be applied. iϋ) The use of a non return instead of an underwater seal improved mobility, in that a patient can move freely without being concerned about breaking the underwater seal. In addition, as the collection chamber fills with fluid there is no increase in the resistance to drainage. iv) After thoracic surgery, if a patient wants to be mobile, but large drainage containers or bags are being used for drainage these devices often pull and agitate the surgical wounds due to carrying arrangements and straps. If the MIS thoracic drainage unit is used its position on a belt on a patient hip provides no such inconvenience. Preliminary studies indicate that the system of the invention allows negative intrapleural pressure to be maintained both with and without suction. Figure 3 demonstrates that suction works on the system as suction pressure moves from lOppm (3A) to 2ppm (3B) . The system is opened to air (3C) and the portable suction unit is introduced (3D) and switched off (3E) and on again (3F) . Figure 4 demonstrates that the addition of water to visual air flow indicator does not impair function (4A) , that portable suction works (4B) and that "blow- out" valve works when system is occluded (4C) .

Claims: CLAIMS 1. A portable device for the collection of thoracic fluid, comprising a collection chamber having an inlet for connection to a patient, a one way valve that permits passage of thoracic fluid from the patient to the collection chamber through the inlet and a portable suction unit that co-operates with the collection chamber for evacuation of air therefrom. 2. A portable device for the collection of thoracic fluid as claimed in Claim 1 wherein the collection chamber and the suction unit are each of the size and weight that allows them to be carried by a patient. 3. A portable device for the collection of thoracic fluid as claimed in any of the preceding claims wherein the one way valve, the inlet and the connection of the chamber with the suction unit are disposed on a removable lid of the chamber. 4. A portable device for the collection of thoracic fluid as claimed in any of the preceding claims wherein the lid of the container has at least two valves, one of which enables evacuation of air from the container, the other valve enables collection of thoracic fluids. 5. A portable device as claimed in any of the preceding claims wherein the collection chamber collects amounts from 0.15 to 0.75 Its. 6. A portable device as claimed in any of the preceding claims wherein the collection chamber is curved to allow ease of placement on a patient's hip. 7. A portable device as claimed in any of the preceding claims wherein suction levels of up to 40cms H 2 0 can be applied. 8. A portable device as claimed in any of the preceding claims comprising attachment means to enable a belt to be attached. 9. A portable suction unit as claimed in any of the preceding claims wherein the lid section is compatible with the container size and comprises features chosen from the group comprising a sealed non-return valve, a visible flow indicator, a variable suction control, a positive pressure release valve, a detachable tube set, suction port and an air sample port. 10. A portable device as claimed in any of the preceding claims wherein the portable suction unit comprises means to allow it to be attached to a belt. 11. A portable device as claimed in any of the preceding claims wherein the portable suction unit is battery operated. 12. A portable device as claimed in any of the preceding claims wherein the portable suction unit has an operating flow rate of between 1.5 and 3 Its per minute. 13. A collection chamber for use in a portable device as claimed in any of the preceding claims. 14. A suction unit for use in a portable device as claimed in any of the preceding claims.

Inventors: HASTINGS STUART, HILL DAVID, LYON JAMES, WALLER DAVID, HASTINGS, STUART, HILL, DAVID, LYON, JAMES, WALLER, DAVID
Applicants: HASTINGS STUART, HILL DAVID, LYON JAMES, ROCKET MEDICAL PLC, WALLER DAVID, HASTINGS, STUART, HILL, DAVID, LYON, JAMES, WALLER, DAVID
Application year: 1998
Main classification: A61M1
IPC codes: A61M1