Ventilator-Associated Pneumonia
Introduction
Introduction to ventilator-associated pneumonia Ventilatorassociated pneumonia (VAP) refers to pneumonia that occurs within 48 hours after mechanical ventilation (MV) to 48 hours after extubation. It is an important type of hospital-acquired pneumonia (HAP), of which MV Pneumonia occurred within 4 days was early-onset VAP, and 5 days was late-onset VAP. basic knowledge The proportion of illness: 0.005%--0.007% Susceptible population: elderly patients with long mechanical ventilation Mode of infection: non-infectious Complications: respiratory failure
Cause
Ventilator-associated pneumonia
VAP has certain characteristics of endemic and epidemic diseases, and its pathogen spectrum varies according to different regions, and is closely related to basic diseases and previous antibiotic treatment, transmission routes, and sources of pathogenic bacteria. Among the pathogens, bacteria are the most common, accounting for more than 90%, of which Gram-negative bacilli are 50%-70%, including Pseudomonas aeruginosa, Proteus, and Acinetobacter. Gram-positive cocci 15%-30%, mainly Staphylococcus aureus. In early-onset VAPs, mainly non-multi-drug resistant bacteria. Such as Streptococcus pneumoniae, Haemophilus influenzae, MSSA and sensitive intestinal Gram-negative bacilli (such as Escherichia coli, Klebsiella pneumoniae, Proteus and Serratia marcescens). Late-onset VAP is a multi-drug resistant strain. Such as ESBL-producing Klebsiella pneumoniae and Acinetobacter baumannii, resistant intestinal bacteria, Stenotrophomonas maltophilia, MRSA and so on. At present, the proportion of fungal infections is gradually increasing. Consider the following reasons: 1 The age of the patient, the underlying disease state, the low resistance, and the long hospital stay increase the hospital infection; 2 The application of immunosuppressive agents and hormones makes the body resistant. 3; tracheal intubation and other invasive procedures, the local defense mechanism is impaired, and the pathogens of the upper respiratory tract are easy to spread to the lower respiratory tract; 4 the widespread use of broad-spectrum antibiotics makes the proliferation of resistant conditional pathogens predominate, resulting in The flora is dysregulated and the fungal infection rate increases.
Prevention
Ventilator-associated pneumonia prevention
1, primary prevention
Also known as etiological prevention, this stage of the disease has not occurred, but risk factors already exist, such as critical illness of the patient such as liver, brain and kidney and other important organ failure, weak body resistance, advanced age, mental stimulation, low mood, etc. There are infection sources such as respiratory system, digestive system, and urinary tract infections. This level of prevention can be divided into promoting health and special protection.
(1) Promote health and actively treat primary diseases: carry out health education, pay attention to reasonable nutrition, and reduce digestive system function in the elderly. Therefore, elderly patients should be fed a nutritious and digestible diet, and medical staff and their families should be more elderly. Conversation, comfort and encouragement are the patient's confidence in fighting the disease, maintaining an optimistic attitude and preventing the invasion of pathogens.
(2) Special protection:
1 Strict management of patients, pathogens and control of environmental pollution: patients with hospital-acquired pulmonary infections and pathogens do not have obvious contagiousness, so the general hospital does not require isolation treatment for most of these patients, but According to foreign literature reports, such as mycoplasma pneumonia and drug-resistant streptococcus pneumonia and other diseases have occurred in the outbreak of nosocomial infections, one of the measures to treat patients is relatively concentrated treatment, in the conditional hospitals, the following pathogen infection is best relative isolation treatment: Influenza virus, respiratory syncytial virus, Legionella, mycoplasma, drug-resistant Staphylococcus aureus, Streptococcus and Pseudomonas aeruginosa, etc., and other patients who are admitted to the pathogen, family members and patients in the incubation period should also be isolated. To prevent cross-infection, and to monitor the suspected water source and air-conditioning system, so as to prevent the outbreak of infection.
2 The route of transmission of the infection is cut off: As mentioned above, the disease is mainly transmitted by air and droplets. In addition, it can be caused by various methods such as contact and interventional operation. The clinical work should be prevented according to the specific situation. Such as air disinfection, strengthen airway management, carefully perform various operations, thoroughly wash hands and properly handle patient secretions, etc., conditional units should use air filtration and purification devices.
3 protection of susceptible patients: the elderly are susceptible to hospital-acquired pneumonia, should be protected according to specific circumstances, in principle, the ward should be regularly ventilated, disinfected, patients should try to live in the small ward, and strictly close contact between patients, All kinds of operations should be gentle, the drugs should be applied reasonably, the diet should be rich in nutrients and easy to digest and absorb, if necessary, use immunopotentiators to improve the patient's immunity.
2, secondary prevention
This prevention mainly includes early detection and timely treatment.
(1) Early detection: elderly hospitalized patients are high-risk groups with pneumonia in the hospital. They should be carefully observed and regularly checked. If there is fatigue, general discomfort, anorexia or mild cough on the basis of the original disease, physical examination should be performed. And laboratory tests to detect early infections in the lungs.
(2) Treatment: Once hospital-acquired pneumonia is found, it should be treated promptly, given effective antibiotics, treated according to different pathogens, treated with anti-virus or antibiotics and anti-fungal drugs, timely control of disease, prevention of disease changes and avoiding concurrency The occurrence of the disease.
3, three levels of prevention
Also known as clinical prevention, it is mainly to use a variety of clinical methods to make pneumonia recover soon and reduce the adverse consequences caused by the disease. Old hospital acquired pneumonia can be combined with some complications, and it is extremely important to actively treat these complications.
(1) Respiratory failure: a high incidence, strengthen oxygen therapy, if necessary, ventilator treatment, if still do not improve can consider tracheal intubation, mechanical ventilation;
(2) Heart failure is one of the main causes of death in pneumonia. Once heart failure occurs, it is immediately given to the heart and diuretic treatment;
(3) Arrhythmia: Antiarrhythmic drugs can be selected according to different types of heart rhythms; correcting water and electrolyte disorders is also extremely important;
(4) shock: more common in hypovolemic shock and septic shock, supplement blood volume, rational use of vasoactive drugs.
Complication
Ventilator-associated pneumonia complications Complications, respiratory failure
There are many complications of pneumonia, such as respiratory failure, heart failure, pulmonary edema, arrhythmia, respiratory acidosis, pulmonary encephalopathy, gastrointestinal bleeding, hydroelectric medium disorder, shock, acute myocardial infarction, followed by pleurisy, empyema and so on.
Symptom
Ventilator-associated pneumonia symptoms Common symptoms Fever with cough, slightly... Difficulty breathing
VAP is one of the common and serious complications in mechanical ventilation. Once a patient develops VAP, it is easy to cause difficulty in offline, thus prolonging the length of hospital stay, and even threatening the life of the patient, leading to death.
Examine
Ventilator-associated pneumonia
The lung histopathology display and microbiological discovery of pathogenic microorganisms and their agreement are generally recognized as the gold standard for VAP diagnosis. This diagnostic criteria requires that traumatic examinations are not easily accepted by patients and doctors, and there are certain difficulties in clinical application.
Diagnosis
Diagnosis and identification of ventilator-associated pneumonia
Guidelines for the diagnosis and treatment of hospital-acquired pneumonia (draft) based on the Chinese Medical Association Respiratory Diseases Branch. Exclude pulmonary diseases such as tuberculosis, lung tumors, and atelectasis: 1 after 48 hours of ventilator use; 2 compared with chest smear before mechanical ventilation, lung infiltration shadow or new inflammatory lesions; 3 lung consolidation Signs and / or lung auscultation can be heard of wet rales, and have one of the following conditions: a. blood cells > 10.0 × 109 / L or < 4 × 109 / L, with or without nuclear transfer; b. fever, Body temperature > 37.5 ° C, a large amount of purulent secretions in the respiratory tract; c. New pathogens were isolated from bronchial secretions after onset.
