FIELD OF THE INVENTION
[001] The present invention generally relates to microbiology.
[002] More particularly, the present invention relates to the Diagnostic method for VAP based on clinical and microbiological criteria.
BACKGROUND FOR THE INVENTION:
[003] By reference to US application no. US2012006331A1 by Virginia Commonwealth University dated 2011-07-13, titled” Prevention of ventilator associated pneumonia (vap)” discloses ventilator associated pneumonia (VAP) may be prevented in a patient, or its occurrence reduced in a population of patients, by using an anti-VAP device or an anti-VAP material such as an anti-VAP mouthpiece that absorbs secretions. By reducing the problem of bacterial-containing secretions that otherwise build up in the airway of, and elsewhere in, the intubated patient, VAP can be prevented from occurring in intubated patients, such as patients intubated with an endotracheal tube (ETT) or a nasogastric tube. Anti-VAP mouthpieces also are usable in non-intubated patients to maintain oral hygiene.
[004] By reference to CN application no. CN104056308A by Huzhou University dated 2014-06-20, titled” Method for preventing ventilator-associated pneumonia” discloses a method for preventing VAP (ventilator-associated pneumonia). Chlorhexidine is used for washing at the same time of intermittent subglottic drainage. A mechanically-ventilated patient is subjected to intermittent washing and suction, so that the damage of negative pressure to airway mucosa is relieved; meanwhile, chlorhexidine is used for washing, so that bacteria is killed under the condition of not producing drug-resistant strains, and the incidence of VAP is lowered.
[005] By reference to US application no. US2006107962A1 by Virginia Commonwealth University dated 2005-09-02, titled” Prevention of ventilator associated pneumonia (VAP)” discloses ventilator associated pneumonia (VAP) may be prevented in a patient, or its occurrence reduced in a population of patients, by using an anti-VAP device or an anti-VAP material. By reducing the problem of bacterial-containing secretions that otherwise build up in the airway of the intubated patient, VAP can be prevented from occurring in intubated patients, such as patients intubated with an endotracheal tube (ETT) or a nasogastric tube.
[006] By reference to US application no. US2009014009A1 by Kimberly Clark Worldwide Inc dated 2007-07-13, titled” Toroidal endotracheal cuffs for ventilator associated pneumonia reduction” discloses an airway ventilation device for insertion in an elongated body cavity is provided. The airway ventilation device includes an endotracheal tube and an inflation cuff. The inflation cuff is toroidal in shape and includes one or more recessed attachment zones which allow for movement of the endotracheal tube without breaking the seal between the inflation cuff and the elongate body cavity.
[007] By reference to US application no. US2007268480A1 by Kaye Mitchell G dated 2006-05-18, titled” Bed angle sensor for reducing ventilator-associated pneumonia” discloses apparatus for indicating the angular position of a patient support surface such as a mattress relative to the direction of gravity is disclosed. An angle sensor mounted to a frame associates with the patient support surface to create an output responsive to changes in position relative to gravity. Circuitry transmits an output signal to activate a display of the angular position of the patient support, thereby indicating whether the angular position is within a predetermined range. Preferably, the apparatus has a circuit for activating an indicator light, which is more preferably mounted above the patient support surface. In certain preferred embodiments the apparatus that comprises the light is connected to the headboard, or the like. It is preferred that the apparatus has a memory device for storing positional information comprising at least a predetermined angular measurement, and more specifically that there is a device for storing information pertaining to the length of time said patient support has been set to an angular position within a predetermined range.
[008] By reference to RU application no. RU2007126282A by Kaye Mitchell G dated 2006-05-18, titled” Bed angle sensor for reducing ventilator-associated pneumonia” discloses apparatus for indicating the angular position of a patient support surface such as a mattress relative to the direction of gravity is disclosed. An angle sensor mounted to a frame associates with the patient support surface to create an output responsive to changes in position relative to gravity. Circuitry transmits an output signal to activate a display of the angular position of the patient support, thereby indicating whether the angular position is within a predetermined range. Preferably, the apparatus has a circuit for activating an indicator light, which is more preferably mounted above the patient support surface. In certain preferred embodiments the apparatus that comprises the light is connected to the headboard, or the like. It is preferred that the apparatus has a memory device for storing positional information comprising at least a predetermined angular measurement, and more specifically that there is a device for storing information pertaining to the length of time said patient support has been set to an angular position within a predetermined range.
[009] By reference to RU application no. RU2531929C1 by State Budgetary Educational Institution of Additional Professional Education "Novokuznetsk State Institute for Postgraduate Medical Education" of the Ministry of Health of the Russian Federation dated 2013-10-08, titled” Method for preventing and treating ventilator-associated pneumonia” discloses medicine, namely to anaesthesiology and resuscitation, and can be used in intensive care patients suffering from ventilator-associated pneumonia, or where there is a high risk of development thereof. Stabilizing haemodynamics is followed by 8 turns of a patient's body a day. The cycle is started from 08-00: 3 hours on his/her back, 2 hours on his/her side, 2 hours on the other side, 3 hours on his/her back, 6 hours on his/her stomach, 4 hours on his/her back, 2 hours on his/her side, 2 hours on his/her side. The patient's centre of gravity is changed every 2 hours with the patient lying on his/her stomach and back. Propofol is infused at 2-3 mg/kg/hour 20 minutes before the patient is turned on his/her stomach and continued until the patient's position is changed again. A nitroglycerin infusion is started 5 minutes after the patient is turned on his/her back in a dose of 0.5-1.0 mcg/kg/min and continues for 5 hours. An antibacterial preparation is intermittently or microfluidic single administered 10 min after the patient is turned on the stomach; observing another rate of administration of the antibacterial preparation, one of the administrations is performed 10 minutes after the patient is turned on the stomach.
[010] By reference to UA application no. UA58174A by the National Medical University named after O.O. Bogomolets, National Medical University named after A.A. Bogomolets dated 2002-10-17, titled” Method for preventing and treating ventilator-associated pneumonia” discloses method for preventing and treating the ventilator-associated pneumonia consists in bacteriological assay of the sensitivity of bacteria isolated from lower airways to the antibacterial drugs. Then the antibiotics are administered intravenously. In addition the antibacterial drug is administered endotracheally hourly for 10-20 days taking into account the data on the sensitivity of bacteria to antibiotics.
[011] By reference to US application no. US10835185B2 by National Medical University named after O.O. Bogomolets, National Medical University named after A.A. Bogomolets dated 2002-10-17, titled” Method for preventing and treating ventilator-associated pneumonia” discloses method for preventing and treating the ventilator-associated pneumonia consists in bacteriological assay of the sensitivity of bacteria isolated from lower airways to the antibacterial drugs. Then the antibiotics are administered intravenously. In addition the antibacterial drug is administered endotracheally hourly for 10-20 days taking into account the data on the sensitivity of bacteria to antibiotics.
[012] By reference to US application no. US2015258292A1 by Leland Stanford Junior University dated 2015-03-10, titled” Devices and methods for prevention of ventilator associated pneumonia” discloses devices and methods for preventing ventilator associated pneumonia following intubating a patient with an endotracheal tube (ETT). Secretions that accumulate in the trachea above the ETT cuff are wicked out of the patient.
[013] By reference to US application no. US2021330905A1 by Leland Stanford Junior University dated 2015-03-10, titled” Devices and methods for prevention of ventilator associated pneumonia” discloses devices and methods for preventing ventilator associated pneumonia following intubating a patient with an endotracheal tube (ETT). Secretions that accumulate in the trachea above the ETT cuff are wicked out of the patient.
[014] By reference to US application no. US2010178255A1 by Madhavi Sekharam Kotha, Anupama Kotha dated 2009-01-15, titled” Composition and method to treat otitis media and ventilator- associated pneumonia” discloses composition and method for prevention and treatment of otitis media and ventilator-associated pneumonia are described. The composition is made with GTase inhibitory polyphenol and polyhydric alcohol carrier. The composition is topical for intra-oral and otic use.
[015] However, none of the above-discussed inventions provides such a Diagnostic method for VAP based on clinical and microbiological criteria. The method comprising a plurality of steps.
OBJECTS OF THE INVENTION:
[016] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
[017] The main object of the present invention is to provide a Diagnostic method for VAP based on clinical and microbiological criteria.
[018] Another object of the invention is to provide CDC criteria to diagnose VAP : Ventilated for more than 48 h.
[019] Another object of the invention, endotracheal or tracheal aspirate is collected under all aseptic precautions with mucus trap.
[020] Another object of the invention is to provide 10 ml of nasogastric aspirate collected from indwelling nasogastric tubes, after removing the initial 5 ml.
[021] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY OF THE INVENTION:
[022] According to one aspect of our invention, a Diagnostic method for VAP based on clinical and microbiological criteria comprising the steps of: a) Samples from all these patients are inoculated on MacConkey and blood agar plates; b) The plates are examined after 24 and 48 hours of incubation at 37°C and the pathogens if isolated are identified by Vitek-2; c) Their sensitivity pattern are determined by Vitek-2 or manually by Kirby-Bauer method following CLSI guidelines; d) Multi drug resistant (MDR) pathogens are defined as those resistant to three or more antimicrobial classes.
[023] In another aspect of the invention, new and persistent infiltrates shadow developing in the chest X-ray.
[024] In another aspect of the invention, presence of fever (temperature <96.8 or >99°F).
[025] In another aspect of the invention, white cell count >11,000/ml or <4000/ml.
[026] In another aspect of the invention, declining ratio of partial pressure to the inspired fraction of oxygen (PaO2/FiO2 ratio) is found to be the earliest indicator of VAP.
[027] In another aspect of the invention, the VAP rate per 1000 ventilator days is calculated as the total number of VAPs in ICUs/total number of ventilator days in medical ICU × 1000.

BRIEF DESCRIPTION OF DRAWINGS:
[028] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
[029] Figure 1: illustrates a Diagnostic method for VAP based on clinical and microbiological criteria, as per an embodiment of the present invention.
[030] The referral numerals in the figures refer to: 2, 3, 4, 5, 6, 7 - diagnosis method steps.

BRIEF DESCRIPTION OF INVENTION:
[031] The present invention will now be described hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. While the following description details the preferred embodiments of the present invention is not limited in its application to the details of construction and arrangement of the parts illustrated in the accompanying drawings. With reference to the figures, the enclosed description and drawings are merely illustrative of preferred embodiments and represent several different ways of configuring the present invention. Although specific components, materials, configurations and uses of the present invention are illustrated and set forth in this disclosure, it should be understood that a number of variations to the components and to the configuration of those components described herein and in the accompanying figures can be made without changing the scope and function of the invention set forth herein.
[032] The present invention as illustrated in Figure 1 provides another embodiment of the invention which includes a Diagnostic method for VAP based on clinical and microbiological criteria.
[033] In another embodiment, a total of 1801 patients are intubated and put on Mechanical Ventilation with total ventilator days of 8972 days. Total number of patients who developed VAP is 96 with the VAP rate calculated to be 10.7 %. A preponderance of males (65.6%) over females (34.4%) is seen. The most common age group affected with ventilator associated pneumonia is found to be 50-65 yrs (45.5). Endotracheal purulent secretions are present in all the 96 (100%) patients followed by fever in 92 patients (95.5%). Also the X-Ray findings suggestive of pneumonia are found in all 96 (100%) cases. The most common bacterial isolate in VAP cases is Klebsiella pneumonia: 46 (38.3%) followed by Acinetobacter Baumanii complex: 26 (21.7%) and Pseudomonas aeruginosa:
20 (16.6%).
[034] In another embodiment, ventilator associated pneumonia still continues to pose a major threat in ICU patients. In the present study the incidence of VAP is 10.7% which is lower than many other studies. Simple practices like hand washing and/ hand rubbing is widely considered as an important but underutilized measure to prevent nosocomial infections like VAP. More emphasis needs to be put on early diagnosis and management with appropriate antibiotics in adequate doses based on microbiological culture results.
[035] In another embodiment, therefore, incidence of VAP and the associated microbial flora needs to be studied in local setting so as to allow more effective utilization of antimicrobial agents. This prompted us to study the prevalence, bacteriological profile, antibiotic susceptibility pattern and outcome of VAP patients in an ICU population of a tertiary care center.
[036] In another embodiment, the diagnosis of VAP is based on clinical and microbiological criteria. We used CDC criteria to diagnose VAP : Ventilated for more than 48 h; New and persistent infiltrates shadow developing in the Chest X-ray; presence of fever (temperature <96.8 or >99°F); White cell count >11,000/ml or <4000/ml; declining ratio of partial pressure to inspired fraction of oxygen (PaO2/FiO2 ratio) is found to be the earliest indicator of VAP; Cultures positive from endotracheal secretions.
[037] In another embodiment, pre-existing pneumonia at the beginning of ventilation or those who developed pneumonia within 48 hours of ventilation are excluded from the study.
[038] In another embodiment, endotracheal or tracheal aspirate is collected under all aseptic precautions with mucus trap. 10 ml of nasogastric aspirate is collected from indwelling nasogastric tubes, after removing the initial 5 ml.
[039] In another embodiment, culture methods: Samples from all these patients are inoculated on MacConkey and blood agar plates. The plates are examined after 24 and 48 hours of incubation at 37°C and the pathogens if isolated are identified by Vitek-2. Their sensitivity pattern are determined by Vitek-2 or manually by Kirby-Bauer method following CLSI guidelines. Multi drug resistant (MDR) pathogens are defined as those resistant to three or more antimicrobial classes.
[040] In another embodiment, data entry and analysis are performed using SPSS for windows version SPSS 22.0 software. Data is mainly represented in the form of numbers and percentages. The VAP rate per 1000 ventilator days is calculated as total number of VAPs in ICUs/total number of ventilator days in medical ICU × 1000.
[041] In another embodiment, total number of patients who developed VAP is 96 with the VAP rate calculated to be 10.7 %. (Table 1). The VAP rate is calculated as per CDC guidelines with the formula= Number of patients developing VAP divided by Number of patients on Ventilator multiplied by 1000. This gives VAP rate per thousand ventilator days.

[042] In another embodiment, a preponderance of males (65.6%) over females (34.4%) is seen. The most common age group affected with ventilator associated pneumonia is found to be 50-65 yrs (45.5) (Table2).

[043] In another embodiment, the clinical parameters and risk factors associated with VAP cases are presented in Table-3. Endotracheal purulent secretions are present in all the 96 (100%) patients followed by fever in 92 patients (95.5%). Also the X-Ray findings suggestive of pneumonia are found in all 96 (100%) cases.

[044] In another embodiment, out of 96 cases, the bacterial species isolated are 120 in number because 59 cases are mono-microbial (one bacteria isolated) and 24 cases are polymicrobial (two or more bacteria isolated) and in 13 cases culture is not positive and diagnosis of VAP is made by other criterion.
In another embodiment, the most common bacterial isolate in VAP cases is Klebsiella pneumonia, 46 (38.3%) followed by Acinetobacter Baumanii complex, 26 (21.7%) and Pseudomonas aeruginosa, 20 (16.6%). (Table-4). The antibiotic sensitivity pattern of the isolates is also studied. It is seen that most of the isolates are multidrug resistant. The only antibiotics to which these isolates are susceptible are Carbapenems (Imipenem, Meropenem and Ertapenem), Colistin, Polymyxin B and
tigecycline. Gram positive organisms showed good susceptibility towards Vancomycin and Linezolid. Penicillins, 2nd and 3rd generation cephalosporins, Quinolones and tetracyclines are found to be totally ineffective.

In another embodiment, the outcome of these VAP patients is also studied. Majority of the patients i,e 44 (45.5%) are discharged from ICU or shifted to in-patient wards. 28 (29.5%) patients expired due to one or the other reason and 18 (18.2%) patients left against medical advice (LAMA). Table -5.

[045] In another embodiment, ventilator-associated pneumonia (VAP) is the most common nosocomial infection among mechanically ventilated patients and is the biggest concern for Intensivists or critical care doctors. The incidence of VAP has been reported to vary from 6.6% to 47.05%. However, in the present study it is found to be around 10.7%. Our hospital has adopted a benchmark of VAP according to International nosocomial infection control consortium (INICC) guidelines which is 14.7%. So the infection rates are below the benchmark. Many other Indian studies have reported a very high incidence of VAP- 27.7% and 45.4%.
[046] In another embodiment, VAP is generally seen in elderly patients (10) and in the present study also, the patients in 51-65 years of age are most commonly affected (45.8%) and males are more commonly affected (65.6%) than females (34.4%) (Table-4).
[047] In another embodiment, Klebsiella pneumonia (38.3%) is the commonest organism followed by Acinetobacter baumannii complex (21.7%) and Pseudomonas aeruginosa (16.6%). The other bacteria that are isolated include E.coli, Elizabethkingia meningoseptica, Proteus mirabilis, Enterobacter aerogenes, Staphylococcus aureus, Stenotrophomonas maltophilia and Burkholderia cepacia (Table-6). Some other studies have also found Klebsiella pneumoniae to be the most common organism in VAP presumably due to production of carbapenamases and several other virulence factors(11,12), although most of the studies have found Acinetobacter to be the commonest bacteria(10,13,14) ,perhaps due to production of virulence factors like universal stress protein A and phospholipase D(14,15).
[048] In another embodiment, a total of 120 bacterial isolates are recovered from 96 cases of VAP. This is because in few patients more than 1 bacterium is isolated from the specimen i.e. the aetiology is polymicrobial as observed by other workers also(9).
[049] In another embodiment, the overall case fatality rate for VAP patients is around 29.5%. Most of the bacteria isolated from VAP patients are found to be Gram negative bacteria. Some of the main risk factors identified for developing VAP are emergency intubation, re-intubation, tracheostomy, and longer duration of ventilators. VAP is a serious problem in ICU leading to prolonged hospitalization and its associated financial implications, and mortality. Simple practices like hand washing and/ Hand rubbing is widely considered as an important but underutilized measure to prevent nosocomial infections like VAP. Hence, knowledge of the local patterns of pathogens causing VAP can help the critical care team to facilitate management. Future studies should be attempted to determine whether specific diagnostic or therapeutic strategies could markedly improve VAP outcomes.
[050] The present disclosure described herein above has several technical advantages including, but not limited to,
? New and persistent infiltrates shadow developing in the Chest X-ray.
? presence of fever (temperature <96.8 or >99°F).
? White cell count >11,000/ml or <4000/ml.
? The declining ratio of partial pressure to inspired fraction of oxygen (PaO2/FiO2 ratio) is found to be the earliest indicator of VAP.
[051] The disclosure has been described with reference to the accompanying embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein.
[052] The foregoing description of the specific embodiments so fully revealed the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

We Claim:

1. A Diagnostic method for VAP based on clinical and microbiological criteria comprising the steps of: a) Samples from all these patients are inoculated on MacConkey and blood agar plates; b) The plates are examined after 24 and 48 hours of incubation at 37°C and the pathogens if isolated are identified by Vitek-2; c) Their sensitivity pattern are determined by Vitek-2 or manually by Kirby-Bauer method following CLSI guidelines; d) Multi drug resistant (MDR) pathogens are defined as those resistant to three or more antimicrobial classes.
2. The Diagnostic method for VAP based on clinical and microbiological criteria as claimed in claim 1, wherein new and persistent infiltrates shadow developing in the chest X-ray.
3. The Diagnostic method for VAP based on clinical and microbiological criteria as claimed in claim 1, wherein presence of fever (temperature <96.8 or >99°F).
4. The Diagnostic method for VAP based on clinical and microbiological criteria as claimed in claim 1, wherein white cell count >11,000/ml or <4000/ml.
5. The Diagnostic method for VAP based on clinical and microbiological criteria as claimed in claim 1, wherein declining ratio of partial pressure to inspired fraction of oxygen (PaO2/FiO2 ratio) is found to be the earliest indicator of VAP.
6. The Diagnostic method for VAP based on clinical and microbiological criteria as claimed in claim 1, wherein the VAP rate per 1000 ventilator days is calculated as total number of VAPs in ICUs/total number of ventilator days in medical ICU × 1000.
7. The Diagnostic method for VAP based on clinical and microbiological criteria as claimed in claim 1, wherein total number of patients who developed VAP is 96 with the VAP rate calculated to be 10.7 %.