Overview.
Citrobacter pneumonia (CP) is an inflammation of the lungs caused by infection with Citrobacter. Citrobacter is a member of the genus Citrobacter in the family Enterobacteriaceae, which consists of three species, namely, Citrobacter heterogeneus, Citrobacter frondii, and Citrobacter malonate-free. Citrobacter pneumonia is most commonly seen in hospital-acquired infections, and the clinical manifestations are similar to those of general acute bacterial pneumonia. The main symptoms are chills, fever, cough, yellow or white mucous sputum, chest pain, and dyspnea. Some patients may have gastrointestinal symptoms such as abdominal pain and diarrhea.
Etiology
Citrobacter pneumonia is an inflammation of the lungs caused by infection of the lungs by the bacterium Citrobacter.
Symptoms
1. Symptoms
The main symptoms are chills, fever, cough, coughing up yellow sputum or white mucous sputum, chest pain, and dyspnea. Some patients may have gastrointestinal symptoms such as abdominal pain and diarrhea. As B. citriodora pneumonia can be seen in septic pneumonia, the systemic toxicity symptoms are more obvious. However, for the original chronic obstructive pulmonary disease and other secondary B. citriodora pneumonia, the symptoms may be atypical, due to the existence of the primary disease and mask the symptoms of pneumonia. Patients may show high fever, coughing up yellow sputum, respiratory failure, heart failure, or aggravation of the primary disease.
2. Physical signs
Breath sounds may be thickened, breath sounds are reduced in the early stage of the disease, and wet rales can be heard in the dissipation stage. When there are solid changes in the lung lobes and segments, there may be increased tremor in the corresponding lung lobes and segments, turbidity on percussion, and bronchial breath sounds or wet rales may be heard. If complicated by pleural effusion, there may be a decrease in tremor and respiratory sounds on the side of the effusion. In addition, some patients with serious conditions may have shortness of breath, cyanosis, decreased blood pressure and jaundice.
Examination
1. Laboratory examination
(1) Routine blood counts Peripheral blood leukocyte and neutrophil counts may be increased, but some patients with severe infections may have decreased counts.
(2) Sputum smear: A large number of gram-negative bacilli may be found.
(3) Arterial blood gas analysis PaO2 may decrease in patients with severe pneumonia, and some patients may have elevated PaCO2. And there may be different degrees of acid-base imbalance.
(4) Blood biochemical examination Some patients may have elevated urea nitrogen, creatinine, transaminase and bilirubin.
2. Pathogenetic examination
(1) Blood culture B. citriodora pneumonia is mostly positive in septic patients. Generally, the positive rate of blood culture is higher in hematogenous B. citriodora pneumonia. Sometimes blood culture is negative and bone marrow culture is positive.
(2) Sputum culture This method is simple, convenient and easy to be accepted by patients, but it is easy to be contaminated by parasitic bacteria in the upper respiratory tract, which affects the accuracy of the results. Select patients to cough out sputum in the lower airway after cleaning and gargling with 3% hydrogen peroxide, and judge the qualified sputum specimen according to the number or proportion of epithelial cells and leukocytes in the sputum smear in the field of view of the low-power microscope, which can greatly improve the positive rate and the accuracy of diagnosis.
(3) Lower respiratory tract secretion culture More accurate, but traumatic.
(4) Culture of pleural fluid, cerebrospinal fluid, urine, etc. Positive results for Citrobacter can be obtained by the above methods.
3. Auxiliary examination
X-ray examination or chest CT examination, the imaging changes of B. citriodora pneumonia are mainly manifested as bronchopneumonia, which may be focal infiltration shadow or diffuse bilateral lower lung infiltration shadow, and small lung abscess.
Diagnosis
Diagnosis is made on the basis of history, clinical manifestations and chest imaging and pathogenetic findings.
Treatment
The principle of treatment is to use sensitive antibiotics to kill the pathogen, strengthen the drainage of bronchial secretion, improve the lung gas exchange, strengthen the primary disease and nutritional supportive therapy, and prevent and control the complications.
1. Antibiotic treatment
Early selection of sensitive antibiotics is the key to treatment. Now it is believed that the third generation cephalosporin and quinolone antibacterial drugs still have strong antibacterial activity against B. citriodora. The sensitivity of different Citrobacter species to antibiotics varies greatly. Therefore, antibiotic application should be based on drug sensitivity to cephalosporins or quinolone antibacterial drugs. Before drug sensitivity, empirical anti-infective treatment can choose third-generation cephalosporins or quinolone antimicrobial drugs in combination with aminoglycosides such as amikacin (butylated kanamycin). The following points should be noted when applying antibiotics:
(1) Send blood, sputum, etc. for bacterial culture and drug sensitivity test before using antibiotics, and ask whether antibiotics have been applied in the past, the type, dosage, method of medication and efficacy, in order to consider whether there are drug-resistant strains.
(2) Bacteria and drug sensitivity should be examined regularly, and antibiotics should be adjusted according to the results of drug sensitivity and efficacy response. For those who do not have the results of drug sensitivity, they can use a kind of third-generation cephalosporin or quinolone antibiotics in combination with aminoglycosides such as amikacin.
(3) The principle of early, sufficient amount, intravenous drug and sufficient course of treatment should be followed. For critically ill patients, it is preferable to use two combinations of drugs, and it is preferable to use the drug for 4-6 weeks for patients with bacteremia with B. citriodora pneumonia. However, attention should be paid to the detection of liver and kidney function.
(4) For patients with decreased neutrophil count, effective antibiotic treatment is recommended, such as piperacillin/triazobactam combined with amikacin (butamidokanamycin) or cephalosporin (hydroxycarboxyoxamide) or imipenem.
2. Promote sputum expulsion and correct hypoxia
For B. citriodora pneumonia, patients should be encouraged to cough and expectorate; for those with thick and sticky sputum, nebulized inhalation can be carried out to expel sputum while supplementing water, and bronchodilators and expectorants should be applied to keep the respiratory tract open. Oxygen inhalation or ventilator-assisted ventilation can help correct hypoxemia in time and prevent the occurrence of cardiac, renal, hepatic and cerebral failure.
3.Nutritional support treatment
If C. citriodora pneumonia is accompanied by primary diseases and complications, it should be treated actively and supplemented with sufficient nutrition. Fresh plasma, human albumin, human blood gammaglobulin (Gammaglobulin) can be appropriately transfused to severe patients, and recombinant human granulocyte colony-stimulating factor can be used to treat those with decreased white blood cell or granulocyte counts along with active anti-infective treatment. Enhanced nursing care can prevent cross-infection.