Methods and apparatus for reducing tracheal infection using subglottic irrigation, drainage and servoregulation of endotracheal tube cuff pressure

• US 5,582,167 A
• Filed: 03/02/1994
• Issued: 12/10/1996
• Est. Priority Date: 03/02/1994
• Status: Expired due to Fees

• Current Assignee: Thomas Jefferson University (Main Line Health System)
• Original Assignee: Thomas Jefferson University (Main Line Health System)
• Inventors: Joseph, Jeffrey I.
• Primary Examiner(s): Lewis, Aaron J.
• Application Number:
  US08/204,481
• Time in Patent Office: 1,014 Days
• Field of Search: 128/202.22, 128/207.15, 128/207.14, 128/205.23
• US Class Current: 128/207.15
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 16/0438 Liquid-filled
• CPC Class Codes: A61M 16/044 External cuff pressure control or supply, e.g. synchronisation with respiration
• CPC Class Codes: A61M 16/0463 combined with suction tubes, catheters or the like; Outside connections
• CPC Class Codes: A61M 16/0479 above the cuff, e.g. giving access to the upper trachea
• CPC Class Codes: A61M 16/0486 Multi-lumen tracheal tubes

Abstract

An integrated system providing a mechanical and chemical barrier against the spread of infected secretions into the distal trachea is disclosed. An endotracheal tube used for patient airway management and provides a means to conveniently irrigate and drain the subglottic region below the vocal cords and above an inflated cuff. The subglottic region accumulates liquid secretions that may channel past an inflated endotracheal tube cuff, providing the necessary bacterial inoculum leading to bronchitis and nosocomial pneumonia. An irrigation channel delivers liquids such as saline or antibiotic and antifungal medications for mucosal hydration, and bactericidal action against infected subglottic secretions. An outer sleeve surrounding the endotracheal tube forms a suction lumen for removing the secretions. The tapered and compliant nature of this sleeve at body temperature allows a large suction channel without the need to greatly enlarge the outside diameter of the endotracheal tube at the vocal cord level. Electronic and mechanical controls provide regulated volume infusion and regulated suction. In addition, cuff pressure is servoregulated to the lowest pressure that provides a tracheal seal and rapid adjustment of cuff pressure so that peak airway pressures are attenuated, thus preserving mucosal perfusion. Pneumonia and patient mortality are thus prevented.

Claims

1. An integrated system providing a mechanical and chemical barrier against the spread of secretions into the distal trachea comprising an endotracheal tube, wherein the endotracheal tube comprises:

a thin walled, compliant outer sheath defining a suction channel concentric with an outer wall of the endotracheal tube for removing infected secretions from a subglottic region below the vocal cords and above an inflated cuff, the outer sheath terminating immediately above the inflated endotracheal tube cuff to create a substantially annular suction lumen; and

an irrigation channel integral with the outer wall and separate from the annular suction lumen for delivering a non-viscous liquid to the subglottic region for tissue hydration and the dilution of bacterial inoculum, whereby delivery of antibiotic and antifungal medication to the subglottic region provides a chemical barrier against the distal spread of infected secretions, the irrigation channel further providing infusion of topical local anesthetics that are subsequently drained, whereby the local anesthetics produce a numbing field block for awake intubated patients,

the system further comprising an electronic and mechanical control device for regulating and integrating irrigation, suction, and cuff pressure, wherein subglottic irrigation will cease if suction or cuff pressure regulation malfunction and wherein an alarm condition is indicated if any one of irrigation, suction and cuff pressure regulation are not functional, wherein cuff pressure is regulated by a cuff pressure autoregulator comprising;

an air compressor;

a gas reservoir;

a pneumatic control valve;

an electronic pressure transducer and servoregulator;

a digital display; and

an electronic alarm system,

wherein the air compressor provides cuff pressure control within about 0.30 seconds of a change in pressure to a pressure within 2.0 mm Hg of a desired pressure in the range of 0-60 mm Hg, with a default pressure of about 15 mm Hg,

whereby compressed gas from the compressor travels through a cuff pressure control line to connect with a cuff inflation channel in the endotracheal tube.

2. The system of claim 1, wherein the suction channel is connected to wall suction that is down-regulated to an adjustable pressure of about 150 mm Hg and further comprises a mechanical timer for timing control of suction activation and quiescence, whereby suction is activated for a period of about 15-60 seconds followed by a several minute period of quiescence;

and further connect a suction canister.

3. The system of claim 1, wherein electronics integrate the function of the system such that liquid infusion is halted if cuff pressure or suction pressure are lost, and wherein electronic alarms provide assurance to the proper function of the system.