Diagnosis, management and prevention of ventilator-associated pneumonia in the UK.

BACKGROUND AND OBJECTIVE: Ventilator-associated pneumonia is a nosocomial infection that occurs in patients receiving mechanical ventilation for >48 h. Many aspects of its diagnosis, treatment and management are controversial. We used a postal questionnaire to survey current practice within the UK. METHODS: Questionnaire study of 207 general intensive care units in the UK. RESULTS: The response rate was 77.3%. Regarding diagnosis, 30% of units obtained specimens from the lungs invasively, while the remainder relied on tracheal aspirates. In only 28.2% of units using tracheal aspirates were results reported in a quantitative manner. A clinical suspicion of ventilator-associated pneumonia would lead to the administration of empirical antibiotic therapy in the majority of units (77.2%), opinion being almost equally divided on whether this should be mono (49.1%) or combination therapy (50.9%). Although most units received regular microbiology feedback (90.5%), the involvement of a microbiologist in the antibiotic decision-making process was variable. Antibiotics were continued for a median of 7 days (inter-quartile range 5-8.5, range 2-14 days). Compliance with the principal methods of ventilator-associated pneumonia prevention was good. CONCLUSION: There is widespread variation in the methods used for the diagnosis of ventilator-associated pneumonia within the UK. The majority of units rely on non-quantitative analysis of tracheal aspirates. This technique has a high percentage of false-positives, and suggests widespread over utilization of antibiotics. However, most agree that antibiotics should be given empirically when there is a clinical suspicion of ventilator-associated pneumonia. The widespread introduction of 'ventilator bundles' appears to have ensured that most units actively take measures to prevent ventilator-associated pneumonia.

Manifestation of tuberculosis in patients with human immunodeficiency virus: a large Indian study.

BACKGROUND: Government Hospital of Thoracic Medicine, Tambaram Sanatorium, Chennai, is the largest HIV-care center in South East Asia. As many as 29,300 HIV patients visited this center at least once in the year 2005 for care and support. OBJECTIVES: Clinical manifestations and the modes of presentation of tuberculosis were assessed among 12,750 adult and adolescent patients with human immunodeficiency virus (HIV) attending the hospital for the first time. MATERIALS AND METHODS: Database of Hospital Information System, specially evolved for managing patients afflicted with tuberculosis and HIV, was utilized. The particulars confined to patients with tuberculosis and HIV co-infection who visited the hospital for the first time from January to December 2005 were considered for the analysis. Proportion test and Chi-square test with Yates correction were done. RESULTS: As many as 12,750 adult and adolescent HIV-confirmed patients were screened for the possible presence of tuberculosis. Out of them, 4,383 (34.4%) patients had tuberculosis. Among them, 2,448 (55.9%) had pulmonary tuberculosis, and the remaining 1,935 (44.1%) had either disseminated or extra-pulmonary tuberculosis (P<0.001). Positive sputum-smear microscopy for acid fast bacilli was evident in 1,363 (31.1%) patients; however, it was significantly lower compared to positive smear rate of 44% in HIV patients (P< 0.001). CONCLUSION: Tuberculosis was found to be the predominant co-infection among the symptomatic patients infected with HIV attending the largest care center for the first time in India. Advanced tuberculosis, disseminated tuberculosis and sputum smear negative pulmonary tuberculosis were the presenting clinical manifestations in 44% of the patients, as they had moderate to advanced immunosuppression. Early detection of tuberculosis co-infection is absolutely necessary.

Prevalence of acquired MDR-TB and HIV co-infection.

BACKGROUND: Mounting prevalence of primary and acquired multidrug-resistant tuberculosis in India is a sorry reminder of all round failure in our fight against tuberculosis and also of the necessity for new effective strategies. OBJECTIVES: (1) To assess the prevalence and pattern of drug resistant pulmonary tuberculosis among treated patients or on those on treatment without adequate response and (2) to evaluate HIV seropositivity among MDR-TB patients. METHODS: Pulmonary TB patients, who had at least six months of unsuccessful anti-tuberculous treatment were selected for the study. Their sputum specimens were examined for M. tuberculosis culture and drug sensitivity pattern and serological examinations for HIV infection were carried out. RESULTS: Sputum specimens of 618 patients' (61.8%) of a total of 1000 examined had shown culturable M. tuberculosis. Four hundred ninty-five patients (49.5%) were found to expectorate tubercle bacilli resistant to one or more anti TB drugs. MDR-TB was detected in 339 patients (33.9%). HIV seropositivity among MDR-TB was 4.42%. Significantly, 245 patients (24.5%) had tubercle bacilli resistant to one or more reserve drugs too (ethionamide, kanamycin and/or ofloxacin). CONCLUSIONS: Prevalence of MDR-TB was high in the study population. It is essentially an acquired condition. Its association with HIV disease was at present on the lower side, an observation contrary to published western literature. Higher rates of resistance for reserve drugs (ethionamide, kanamycin and/or ofloxacin) in patients who never had these drugs in their earlier treatment schedules suggest the possibility of emerging spontaneous drug resistant mutants.

Experimental studies on synergism between aminoglycosides and the antimicrobial antiinflammatory agent diclofenac sodium.

The antiinflammatory agent diclofenac sodium (Dc) exhibited remarkable antibacterial effects both in vitro and in vivo. Fifteen different bacteria sensitive to Dc as well as to a number of common antibiotics were tested for synergistic effects in vitro. Disc diffusion test with Dc and aminoglycosides assessed by stringent computation showed clear-cut synergism. Synergism between Dc and streptomycin (Sm) was found to be statistically significant (p < or = 0.01) when compared with their individual effects. By the checkerboard assessment procedure, the fractional inhibitory concentration (FIC) index of this combination was found to be 0.49, confirming synergism. The mouse protective capacity of this combination was then evaluated in vivo against S. typhimurium as the virulent infecting bacterium, and the size of bacterial load determined from infected autopsied animals. Statistical analysis by Student's 't' test suggested this drug combination is highly synergistic; synergism was also noted between Dc and other aminoglycosides.

Antibacterial activity of the antiinflammatory agent diclofenac sodium.

Antimicrobial property of ten antiinflammatory drugs was tested with eleven sensitive bacteria belonging to both Gram positive and Gram negative types. Since most of the bacteria were moderate to highly sensitive to diclofenac (Dc), this compound was tested in vitro against 397 bacteria, most of which were inhibited by Dc at 50-100 micrograms/ml level. When tested in vivo, Dc at 1.5 and 3.0 micrograms/g body weight of a Swiss strain of white mice, could significantly protect the animals challenged with 50 MLD of Salmonella typhimurium NCTC 74. According to chi 2 test the in vivo data were highly significant (P < 0.001).

In vitro and in vivo antimicrobial action of fluphenazine.

The antipsychotic drug fluphenazine was obtained in a dry powder form and was screened with respect to 482 strains of bacteria, which included 170 Gram-positive and 326 Gram-negative strains. Nutrient agar plates containing increasing concentrations of fluphenazine (0-200 micrograms/ml) were used for the determination of the minimum inhibitory concentration (MIC) which was demonstrated by inoculating a loopful of an overnight peptone water culture of the organism on nutrient agar plates and determining the MIC against a control. Fluphenazine was detected to possess pronounced action against both Gram-positive and Gram-negative bacteria at 20-100 micrograms/ml. In the in vivo studies it was seen that when fluphenazine was used at a concentration of 1.5 micrograms/g and 3 micrograms/g mouse body weight both the levels offered significant protection to Swiss strain of white mice when challenged with 50 minimum lethal dose (MLD) of a virulent strain of Salmonella typhimurium 74. The in vivo data with fluphenazine were highly significant (p < 0.001) according to the chi-square test.