Can sputum gram stain be used to predict lower respiratory tract infection and guide empiric antimicrobial treatment: Experience from a tertiary care hospital.

BACKGROUND: The mortality associated with lower respiratory tract infection is high. Indiscriminate use of antimicrobials leads to alteration of respiratory tract flora and development of multi-drug resistance. Rapid diagnostic tests to confirm infection can guide the clinicians about antimicrobial treatment. So the present study was planned to evaluate the role of direct gram stain examination as a rapid and simple test to help clinicians for appropriate patient management. METHODS: The present study was conducted on 1000 respiratory specimens which were processed using conventional microbiological techniques. Gram stain smear and culture results were compared statistically to assess the sensitivity, specificity, positive and negative predictive value. The agreement between gram stain smear examination and culture was calculated using kappa statistics. RESULTS: Potential pathogens were obtained from 28 of 209 deeply coughed out sputum samples (13.3%) and from 19 of 315 saliva mixed sputum samples (6%). Out of 473 tracheal aspirates, 115 (24.3%) had potential pathogens. The sensitivity for predicting infection was higher for good quality sputum samples (54%) as compared to poor quality sputum samples (37%). The gram stain and culture of tracheal samples had a good agreement for predicting infection whereas there was only moderate agreement for sputum sample. CONCLUSION: Gram stain smear examination from respiratory samples can be used to guide empiric antibiotic therapy pending final culture sensitivity results if the attending physicians ensure appropriate sample collection and transport. In absence of these supportive measures smear examination should not be relied upon for empiric treatment.

Survey on de-escalation of empiric broad-spectrum antibiotics treatment for patients in intensive care unit / 中华临床感染病杂志

Objective To investigate de-escalation of empiric broad-spectrum antibiotics treatment for patients in intensive care unit (ICU).Methods Data of the patients discharged from ICU in the Second Affiliated Hospital of Zhejiang University from July 1 to December 31 of 2012 and from July 1 to December 31 of 2013 were retrospectively reviewed.Patients with initial use of empirical broad-spectrum antibiotics within 3 d after ICU admission were included in the study.Clinical data including status of infection,the initial empiric antimicrobial therapy,pathogens culture and adjustment of antibiotics in 5 days were analyzed.Results A total of 841 patients were discharged from ICU during the study periods and antibiotics were used in 786 (93.5％) patients.Among 786 patients,389 (49.5％) were treated empirically with broad-spectrum antibiotics,but only 269 (69.2％) had evidences of bacterial infections.Of the 389 patients with empiric antibiotics use,de-escalation of antibiotics was applied only in 6 (1.54％) patients within 5 days after the initiation of treatment.In 269 patients with evidence of infection,specimen sampling and culture were performed in 248 (92.2％) patients within 3 days,among which 165 samples were positive,and the clinical isolates were mainly multi-drug resistant gram negative bacilli and colonized bacteria in oropharyngeal cavity.De-escalation was applied only in 4 (1.49％,4/269) patients with evidences of bacterial infections.Conclusion Broad-spectrum antibiotics as initial empiric therapy is common for patients in ICU,however de-escalation of empiric therapy is rarely applied even in patients with positive results in pathogen isolation and culture.