Speaking valves are generally utilized for patients that require a tracheostomy for breathing. In certain cases, patients are recovering from a debilitating lung injury or from a serious respiratory illness such as pneumonia that requires the patient's dependency on a ventilator for breathing during the recovery period or for an indefinite period of time. Other patients, such as quadriplegics may require a ventilator for breathing on a permanent basis. Tracheostomies are generally known to result in fewer complications for patients and generally recommended early on during treatment and recovery.
Tracheostomies are utilized via an opening surgically created through the neck into the trachea permitting access for breathing and is commonly done in an operating room under general anesthesia. A tube is usually placed through this opening to provide an airway and to remove secretions from the lungs. Thus, breathing or ventilation is accomplished through the tracheostomy tube rather than through the nose and mouth. The incision into the trachea (windpipe) forms a temporary or permanent opening which connects via the tracheostomy tube to a ventilator so the patient can safely recover while maintaining respiration.
However, one of the problems faced by patients that require a tracheostomy tube is that speaking often becomes a challenge. Exhaled air generally does not pass through their larynx but, rather exits from the tracheostomy tube. A speaking valve is often attached to the tracheostomy tube to direct air flow through the vocal cords when a patient exhales. The speaking valve thus closes during exhalation, causing air to travel up the trachea around the tracheostomy tube, through the larynx and out of the patient's nose or mouth. This re-directed air path permits speech in the patient.
While speaking valves have been implemented to assist the patient with speaking, the use of such valves includes various drawbacks. Some of the concerns with one-way speaking valves have included occlusion problems, safety, high resistance levels, size, adaptability, restriction during inspiration, and leakage of exhaled air backing out through the valve.
Many speaking valves are designed in a biased-closed position that open only during inspiration and start to close before the end of the inspiratory cycle/beginning of the expiratory cycle. The air is then directed around the tracheostomy tube, through the vocal cords and out through the oral and nasal cavities of the patient. Thus, a column of air is trapped within the speaking valve and the tracheostomy tube acts as a buffer to resist movement of secretions that move up the tracheostomy tube and into the speaking valve. Such speaking valves while permitting patients to speak normally have serious drawbacks in connection with their use. First, the tracheostomy tube must operate with the cuff of the tracheostomy tube always completely deflated which otherwise creates a dangerous obstruction to exhaled air flow. Warning labels are often indicated in proximity to the patient's bedside and/or chart in order to monitor the balloon of the patient's cuffed tracheostomy tube. Another drawback is the case in which controlling the ventilation and gross aspiration is required, in order to prevent the tracheostomy tube cuff from being deflated. The speaking valves cannot be used in such cases since it would cause an obstruction to exhaled air flow and the patient would not be able to be safely ventilated. An additional drawback of speaking valves is for unconscious or comatose patients which are unable to speak in such states, and would require constant monitoring when such speaking valves are implemented with ventilation systems. Speaking valves are generally not suitable during extensive sleep patterns of patients, especially in unconscious or comatose patients. An additional complication is that any inadvertent re-inflation of the cuff can also occur with a foam-filled cuffed tracheostomy. The pilot line of a foam-filled cuffed tracheostomy tube must be plugged in to prevent the cuff from re-inflating. Therefore, the use of speaking valves can be hazardous when implemented with a foam-filled cuffed tracheostomy tube.
As described, there exists a need in the art for a ventilator tracheostomy adapter that not only permits optimal use of more advanced ventilator technologies implementing existing tracheostomies or use of an endotracheal tube (i.e. tube placed within the patient's trachea), but which additionally permit the continuous use of the ventilator with marked improvement in the speech of patients or simply, the ability to even speak, while reducing numerous potential complications and drawbacks of existing speaking valves. An advantage of such improved adapter designs is the possibility for refined calibration of continuous ventilator support in both the inspiratory and expiratory phases of respiration which leads to improved weaning of the patient from dependency on the ventilator for breathing as is described in greater detail below.