Clinical And Prognostic Analyses Of HIV/AIDS-associated Severe Pneumonia

Prior to the wide use of highly active antiretroviral therapy (HAART), pneumonia was a very common opportunistic infection in patients with HIV/AIDS. Many patients with HIV/AIDS might suffer from episodes of pneumonia accompanied by respiratory failure during the course of disease because of immunosuppression in this population, and respiratory failure is the main reason for ICU admission and the leading cause of death in patients with AIDS. Despite the availability of HAART in the United States and other developed countries, pneumonia remains the main opportunistic infection in HIV-infected persons and respiratory failure due to severe pneumonia continues to be a common cause of admission in the ICU for some reasons. It will be helpful for choosing optimal strategies for prevention and management and improve the outcome to understand the epidemiology, clinical characteristics and prognostic factors of HIV/AIDS–associated severe pneumonia.ObjectivesThe aim was to: (1) understand the current prevalence and situation of HIV/AIDS-associated severe pneumonia in Guangdong Province; (2) identify the etiology of HIV/AIDS-associated severe pneumonia; (3) explore the prognostic factors and try to find out the early predictors of HIV/AIDS-associated severe pneumonia.1. To investigate the epidemiology and general situation of HIV/AIDS-associated severe pneumonia including age, gender, routes of HIV infection ,underlying diseases, immune status, the annual incidence and mortality, etc; and compare the incidence before and during the HAART era.2. To investigate the etiology of HIV/AIDS-associated severe pneumonia and incidence of drug-resistant bacteria.3. To analyze the current situation of diagnosis and treatment in HIV/AIDS-associated severe pneumonia: including the etiological confirmation rate of diagnosis, use of mechanical ventilation and use of HAART etc, to help clinician choose optimal management strategies.4. To identify the main prognostic factors, the relationships between the outcome and influence factors were studied. The factors includes gender, age, routes of HIV infection, underlying diseases, immune status (CD4+ cell counts), mechanical ventilation, pneumothorax, single or multi-infections, serum albumin, serum LDH, serum creatinine and the use of HAART or not .Subjects and MethodsSubjects:Data were collected from 102 patients with HIV/AIDS-associated severe pneumonia admitted to the 8th People's Hospital of Guangzhou from January 2005 to December 2008. These patients were diagnosed as HIV/AIDS-associated severe pneumonia according to the"Guidelines of AIDS Diagnosis and Treatment"(2006) issued by the Committee of Infectious Disease, Chinese Medical Association (CMA) and the"Guidelines of Diagnosis and Treatment of the community-acquired pneumonia"(2006) issued by the Committee of Respiration Diseases, CMA. Out of the 102 cases, 95 with complete information were studied for the relationships between the outcome and influence factors.Methods:1. Descriptive study was used to study the general information of cases.2. Retrospective case-control study was used to analyze the prognostic factors.3. Statistical analyses: T-test and chi-square or Fisher's exact test was used to compare the difference between two variables where applied; univariate analysis and multivariate logistic regressions were performed to study the relationships between the outcome (survival or death) and different influence factors. A p-value of less than 0.05 was considered to be statistically significant throughout.Results1. The incidence of pneumonia and severe pneumonia in HIV/AIDS patients: the incidence of pneumonia from 2005 to 2008 in the admitted patients with HIV/AIDS was 57.7%(642/1113), with similar annual incidences. It was significantly higher than that (74.4%, 67/90)in patients seen from 1999 to 2001 (P<0.05). The incidence of severe pneumonia was 9.2%(102/1113)with a mortality of 56.9%(58/102).2. The infected microbiological spectra and classified diagnosis of etiology of severe pneumonia: the most frequently encountered pathogens were Pneumocystis jirovecii (62.7%, 64/102), followed by bacteria (59.8%, 61/102), fungi (49.0%, 50/102), Tuberculosis (26.5%, 27/102) and CMV (24.5%, 25/102), respectively. Among 102 cases , Monocontamination was detectd in 17 cases 19.6%) , while mixed infection in 85 cases(80.4%), Staphylococcus and Klebsiella pneumoniae were detected more frequently than other bacteria. A higher incidence of methicillin-resistant Staphylococcus (MRS) and extended-spectrum beta-lactamase-producing Gram negative bacterium (ESBL) in severe pneumonia were detected. The rates of confirmed diagnosis of pathogen in different infections were: TB (88.9%,24/27), bacteria (75.7%,46/61), CMV (60.0%,15/25), Pneumocystis jirovecii (34.4%,22/64) and fungi (18.0%,9/50) respectively.3. The factors that influence the outcome of HIV/AIDS-associated severe pneumonia: Logistic regression analysis showed that mechanical ventilation[OR 6.760, 95%CI (2.126,21.503)], underlying diseases [OR 2.924, 95%CI(1.009,8.475)], higher serum LDH level [OR 0.384,95%CI(0.174,0.846)] and lower serum albumin level [OR 2.877,95%C(I1.331,6.220)] were the predictive factors for the worse outcome. Conclusions1. In Guangdong Province, despite the incidence of HIV/AIDS-associated pneumonia declined in HAART era, it was still the main reason for hospitalization for patients with HIV/AIDS. The incidence and mortality of severe pneumonia remained high.2. Pneumocystis jirovecii and bacteria were the major pathogens of severe pneumonia. Staphylococcus and Klebsiella pneumoniae were the main pathogens of severe bacterial pneumonia. The rates of confirmed diagnosis of pathogen of severe pneumonia were very low, especially in fungi and Pneumocystis jirovecii infections.3. Requiring mechanical ventilation, higher level of serum LDH, lower level of serum albumin and accompanied with serious underlying diseases indicated a worse outcome for the patients with HIV/AIDS-associated pneumonia. Thus, to improve the outcome of HIV/AIDS-severe pneumonia, we should provide better ventilation strategy, take care of the underlying diseases, improve their nutritional status, and furthermore, strengthen multi-disciplinary co-operation.