MXPA00010313A - Aspiration screening process for assessing post surgery patient's risk for pneumonia - Google Patents

Abstract

Whether a post surgery intubated patient is at risk for aspiration-based pneumonia is determined by requiring the patient to inhale an aerosol of tartaric acid (101) that will stimulate a sensory innervation of the patient's larynx, if functionally recovered, thereby causing the patient to cough. The resulting cough or lack of cough is graded (103) to determine whether the patient is at risk for pneumonia caused by the aspiration of matter present in the patient's mouth. In a further embodiment, the inability or difficulty of a patient to voluntarily expel potentially threatening fluid, and matter from the patient's airway can be remedied by repeated applications of the aerosol chemostimulant spray.

Description

ASPIRATION TRACE PROCESS TO EVALUATE THE PNEUMONIA RISK OF A PATIENT AFTER SURGERY FIELD OF THE INVENTION The present invention relates generally to the field of patient recovery after surgery, and is particularly directed to a process based on involuntary cough to determine whether a patient, who has undergone general anesthesia, is at risk of developing pneumonia based on aspiration. This is achieved by having the patient inhale an aerosolized chemostimulant that will stimulate a fully functional (recovered) sensory innervation of the patient's larynx, causing the patient to cough involuntarily. If the patient does not cough, however, it is inferred that the patient's involuntary cough reflex is not yet fully functional, and that the patient is at risk of developing pneumonia based on aspiration.

BACKGROUND OF THE INVENTION Any patient who has been given general anesthesia for a surgical procedure is intubated before surgery. Since the effective and pharmacological anesthetic suppresses the function of the brain stem, including a variety of involuntary physiological responses, not the last of which is the ability to cough and (clean) the upper airway.These reflexes of the brain stem are suppressed until the anesthetic disappears, since the tubing that has been inserted into the patient's airway tends to act as a thick expulsion fluid (eg, secreted saliva) that may be present in the patient's mouth to the airway of the patient and lungs, it is critical that the involuntary cough reflex of the patient be fully functional by the time the patient removes the tube.Unfortunately, there is currently no mechanism to accurately determine whether the patient's ability to clean voluntarily, the airway has been completely restored or not, in reality, since every moment of anesthesia recovery the patient is different, the average standard practice is to have a practically experienced doctor (for example, an anesthesiologist) who observes the patient, and then do an "adequate guess" that the patient's anesthetic state has completely subsidized, and that is "reasonably safe" to remove the patient's tubing, and allow the patient to receive fluids and / or nutrients through the mouth. If the reflex of the patient's involuntary cough is not yet fully restored, however, the patient is at considerable risk of developing pneumonia, as a result of the entrance into the airway from the patient's mouth of what might otherwise be a expelled secretion and / or foreign matter that can be a substrate to feed bacteria. In addition, at one in those cases where a patient has the ability to cough both involuntarily and voluntarily, the patient's condition (e.g., in the case of coronary bypass surgery) can be such that it is extremely difficult and / or painful that the patient coughs voluntarily to cleanse and expel secretions, mucosa and the like, from the patient's airway.

COMPENDIUM OF THE INVENTION According to a first embodiment of the present invention, the potential problem of pneumonia based on aspiration after surgery, discussed above, is easily determined through an aerosol-based screening process, which determines the ability of a patient in recovery. after operation without a pipe, whose reflex of involuntary cough in the larynx has been previously anesthetized (as through the application of a general anesthetic) or compromised by intubation, to cough involuntarily and thus clean the airway of the patient of secretions and / or foreign matter that can be a substrate to feed bacteria and cause pneumonia. For this purpose, the cough reflex of the patient's larynx is evaluated by introducing (spray injection) an aerosolized chemostimulant into the patient's mouth, for the purpose of stimulating similar types of receptor irritants in the larynx of the patient. The aerosol inhalant preferably comprises that described in the U.S. patent. A. No. 5,678,563, entitled: "Aspiration Screening Process for Assessing Need for Modified Barium Swallow Study", the description of which is incorporated herein, comprising a nebulized or aerosolized solution of tartaric acid (tartrate) mixed with saline and supplied through a standard aerosol nebulizer. Although other receptor-specific chemo-stimulants may be employed, studies indicating the inhalation of tartaric acid reveal that inhalation of 20% nebulized tartaric acid will stimulate an involuntary, abrupt and "explosive" cough, 100% of the time in those patients whose reflexes of laryngeal cough have completely recovered from anesthesia and are fully functional. In addition, tartaric acid is considered safe, does not cause pain or discomfort, and has been shown not to cause bronchoconstriction or complications in asthmatics or smokers when inhaled in an aerosolized form. The aerosol stimulant containing tartrate can be injected into the patient's mouth through a respiratory therapist, using a nebulizer for a relatively short period. The patient can be tested a plurality of times at different stimulatory resistances, respectively, to determine if an aerosol resistance can cause an involuntary cough. During each application of successive stimulant, the patient receives progressively increasing concentrations of the aerosol during a prescribed period by breathing in tidal form at intervals of one minute using successively increasing percentage concentrations. If the patient involuntarily coughs as a result of the introduction of any concentration of aerosol stimulant, the cough test by inhalation is terminated, regardless of the percentage of concentrations used. The patient's response to the inhalation test is then rated (for example, as a low risk of pneumonia, if the patient coughs immediately in response to the initial aerosol spray and the cough appears strong or normal), or as a high risk of pneumonia (where the cough appears weak or the patient does not cough easily in response to the initial concentration spray, but requires a more concentrated spray application). If the patient does not cough up by some resistance of the inhaled aerosol stimulant, the cough test by inhalation is terminated, and it is determined that anesthesia of the patient's laryngeal cough reflex has not been fully subsidized, so that the patient remains a high risk of pneumonia and can not be given fluids or nutrients by mouth. In a second embodiment of the invention, using a procedure termed "pulmonary cleansing", involving repeated applications of the tartaric acid aerosol spray described above, the patient is involuntarily forced to cough multiple times and thus remove the fluid potentially threatening and other matter of the patient's airway. This second embodiment of the invention is employed when the condition of the patient is such that it is extremely difficult and / or painful for the patient to have to cough voluntarily to cleanse and expel secretions, mucus and the like from the patient's larynx.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart of the cough-based screening process for diagnosing whether a patient without tubing after surgery is at risk of developing pneumonia based on aspiration, in accordance with the present invention; Figure 2 illustrates diagrammatically the use of an aerosol inhaler in the involuntary cough process of the present invention; and Figure 3 is a flow diagram of the cough-based therapy process for forcing a patient to clean the patient's airway through repeated applications of a cough reflex stimulating aerosol.

DETAILED DESCRIPTION Figure 1 is a flow diagram of the steps of the aerosol-based involuntary cough tracking process of the present invention to clinically diagnose whether there is a potential risk of pneumonia based on aspiration after surgery, introducing (spray injection) a aerosol chemostimulant in the mouth of a patient without tubes, in order to stimulate irritating type receptors or the like in the larynx of the patient. During the first step, 101, an aerosolized chemoestimulant is injected into the patient's mouth by means of a respiratory therapist, using an aerosol inhaler, such as a commercially available Bennatt Twin nebulizer, shown at 22 in Figure 2. As shown in FIG. described briefly, the aerosol chemostimulant preferably comprises a nebulized solution of 20% tartaric acid mixed with saline, as described in the aforementioned patent. Although other receptor-specific chemo-stimulants may be employed, studies involving inhaling tartrate, and presented in the above-identified patent, have shown that tartrate will stimulate in 100% involuntary cough in normal individuals (ie, whose cough reflexes in the larynx are functioning normally (not anesthetized)). In addition, tartrate is considered safe, does not cause pain or discomfort, and has not been shown to cause bronchoconstriction or complications in asthmatics or smokers, when inhaled in an aerosolized form. During the cough test by inhalation, the patient uses a nose clip 20, as shown in Figure 2. The aerosol chemostimulant is preferably inhaled for a prescribed period of time (eg, of the order of 15 seconds). The spray mist output speed may be of the order of 0.2 ml / minute, as a non-limiting example. The patient can be given a plurality of spray applications, up to the prescribed maximum (for example, three times) at different stimulant resistances, in an effort to produce cough. During these successive chemostimulant applications, the patient receives progressively increasing concentrations of the aerosol for a prescribed period of time through tidal-type breathing at 1-minute intervals using successively increasing percentage concentrations (e.g., 20, 50 and 80%). ). If, for any application the aerosol, the patient involuntarily coughs, the cough test by inhalation is terminated, without considering the percentage of concentrations used. If no involuntary cough occurs after the maximum number of spray applications and maximum concentration, the test is also terminated. The patient's response to the inhalation test is then scored in step 103 either as a low risk of pneumonia (as is the case where the patient coughs immediately in response to the initial spray mist) or a high risk of pneumonia ( as in the case where the cough is present but in a reduced form, it does not easily cough in response to the initial concentration spray, but requires a more concentrated spray application, or does not cough at all). As noted above, if the patient fails to cough involuntarily, without considering the resistance of the inhaled aerosol stimulant, it is determined that anesthesia of the cough reflex of the patient's larynx has not been totally subsidized, and the patient is diagnosed as remaining at a high risk of pneumonia based on aspiration due to a neurologically unprotected airway. This guarantees the consideration of re-intubation, placing the patient on a restricted diet, NPO, or alternative feeding strategies, such as gastrostromy percutaneous endoscopy, until the reflex of the patient's involuntary cough has fully recovered. According to a second "treatment" modality of the invention, a flow diagram is shown in Figure 3, showing the inability of a patient to expel potentially threatening fluid and matter from the patient's airway, identified in step 301, and this is overcome through repeated applications, as shown in step 303, of an aerosol chemostimulating spray, as described above in the first embodiment. In the second embodiment, the concentration employed is preferably the lowest concentration, which is effective to stimulate cough. As described above, said inability of the patient to cleanse and expel secretions, mucus and the like from the patient's larynx, can occur in those cases where the patient's condition is such that it is extremely difficult and / or painful to have to cough voluntarily. The number of repetitions of the aerosolized chemostimulant will depend on the response of expulsion of the patient's secretion for each application. After each application, and associated expulsion of secretions by the patient, the patient is examined to determine if an additional aerosol chemostimulant application is required to clean the airway for that treatment. The patient is continuously inspected and the procedure is repeated at various intervals that are necessary to determine that the patient's airway is free of fluid and secretions that constitute a risk of pneumonia based on aspiration. As will be appreciated from the above description, if a patient without tubes after surgery is at risk of aspiration-based pneumonia it is easily determined in accordance with the present invention, requiring the patient to inhale an aerosol that will stimulate a sensory innervation completely. of the patient's larynx, and causes the patient to cough involuntarily. Depending on the response of the patient's cough or lack of it, the patient may be qualified to determine if the patient is at risk of pneumonia. In addition, the inability of a patient to easily expel potentially threatening fluid and matter from the patient's airway can be remedied through repeated applications of the chemoestimulating aerosol spray of the first modality. Although several embodiments have been shown and described in accordance with the present invention, it should be understood that it is not limited to this but is susceptible to numerous changes and modifications as known to one skilled in the art, and, therefore, does not it wishes to be limited to the details shown and described herein, but rather to cover all these changes and modifications as obvious to one skilled in the art.

Claims (15)

1. - A method to evaluate a patient, who has been intubated and anesthetized in the course of a surgical procedure, to determine whether the patient is at risk of developing pneumonia based on aspiration as a result of incomplete functional recovery of the cough reflex involuntary patient, comprising the steps of: (a) having the patient, who has had the tubes removed after the surgical procedure, inhale an aerosol that is effective to stimulate a sensory innervation of the larynx of a normally functional patient causing the patient to cough; (b) in response to the patient without tubes who fail to cough as a result of inhaling said aerosol in step (a) to diagnose said patient without tubes at risk of aspiration-based pneumonia, but in response to the patient's cough without tubes as a result of inhaling the aerosol in step (a), diagnose the patient without tubes as being free of risk of pneumonia based on aspiration.

2. A method according to claim 1, wherein step (a) comprises making the patient without tubes inhale an aerosol containing a chemical that is effective to stimulate irritating or similar types of receptors in the larynx of the patient.

3. A method according to claim 1, wherein step (a) comprises causing said patient without tubes to inhale an aerosol containing tartrate mixed with saline. .

4. A method according to claim 1, wherein step (a) comprises making the patient without tubes inhale an aerosol containing stimulant resistances respectively different from a chemical that is effective to stimulate a sensory innervation of the larynx of a patient without tubes.

5. A method according to claim 1, wherein step (a) comprises making the patient without tubes successively inhale an aerosol containing respectively increasing concentrations of a chemostimulant that is effective to stimulate a sensory innervation of the larynx of the patient without tubes.

6. A method according to claim 5, wherein the chemostimulant is a saline solution of tartrate.

7. A method according to claim 5, wherein step (b) comprises rating the patient's cough without tubes either as being at a low risk of pneumonia if the patient's cough without tubes appears normal in response to dew. in initial spray, or as a high risk of pneumonia if the patient without tubes has a reduced or weak cough in response to initial spray concentration or requires a more concentrated spray application.

8. A method according to claim 5, wherein, during successive inhalations of the stimulant of said chemostimulant, the patient without tubes receives progressively increasing concentrations of the aerosol through tidal-type breathing at prescribed intervals.

9. A method for making a patient who has difficulty cough voluntarily expel potentially threatening fluids and matter from the patient's airway, comprising the steps of: (a) causing the patient to inhale an aerosol that is effective to stimulate a sensory innervation of the patient's larynx, in this way the patient coughs involuntarily and expels the matter in the patient's airway; and (b) repeating step (a) one or more times, as necessary to clean the patient's airway.

10. A method according to claim 9, wherein steps (a) and (b) comprise causing the patient to inhale an aerosol containing a chemical that is ineffective in stimulating irritant or similar types of receptors in the patient's larynx. .

11. - A method according to claim 9, wherein steps (a) and (b) comprise making the patient inhale an aerosol containing resistances to the stimulant respectively different from a chemical that is effective to stimulate a sensory innervation of the larynx of the patient.

12. A method according to claim 9, where the spray contains tartrate mixed with saline.

13. A method according to claim 9, wherein steps (a) and (b) - comprise making the patient inhale successively an aerosol containing respectively increasing concentrations of a chemostimulant that is effective to stimulate a sensorial innervation of the larynx of the patient.

14. A method according to claim 13, wherein the chemostimulant is a tartrate saline solution.

15. A method according to claim 13, wherein, during successive inhalations of the stimulant of said chemostimulant, the patient receives relatively increasing concentrations of the aerosol through tidal respiration at prescribed time intervals. 00P1404 ASPIRATION TRACE PROCESS TO EVALUATE THE RISK OF PNEUMONIA OF A PATIENT AFTER SURGERY SUMMARY It is determined if a patient intubated after surgery is at risk of suffering aspiration-based pneumonia, requiring the patient to inhale a tartaric acid aerosol (101) that will simulate a sensory innervation of the patient's larynx, if functionally recovered, making in this way the patient coughs. The cough or lack of cough resulting is scored (103) to determine if the patient is at risk of pneumonia caused by aspiration of material present in the patient's mouth. In a further embodiment, the inability or difficulty of a patient to voluntarily expel the potentially threatening fluid, and the matter from the patient's airways, can be remedied by repeated applications of the chemostimulating aerosol spray.