Sujatha Sistla

Ventilator-associated pneumonia: A review

Ventilator-associated pneumonia (VAP) is the most frequent intensive-care-unit (ICU)-acquired infection, with an incidence ranging from 6 to 52% [1,2,3,4]. Several studies have shown that critically ill patients are at high risk for getting such nosocomial infections [3,4]. VAP continues to be a major cause of morbidity, mortality and increased financial burden in ICUs [5,6,7,8]. Over the years there has been a significant advance in our understanding of ventilator associated pneumonia. This article reviews the various aspects of VAP such as definition, risk factors, etiological agents, diagnosis, treatment and prevention with emphasis on the recent advances.

Minimizing Wound Contamination in a ‘Clean’ Surgery: Comparison of Chlorhexidine-Ethanol and Povidone-Iodine

Purpose: There is limited work analyzing the efficacy of different antiseptics in reducing wound contamination by the skin flora during hernia repair and its influence on the incidence of wound infection, which continues to be a major problem in the developing world. This study was designed to test if chlorhexidine-ethanol has superior antimicrobial efficacy compared with povidone-iodine. Methods: In a prospective randomized trial, the efficacy of chlorhexidine-ethanol and povidone-iodine in the reduction of colony counts of the skin flora and the incidence of surgical site infection was compared. Results: Both povidone-iodine and chlorhexidine-ethanol produced significant reduction in the skin bacterial colony counts, from 18.66 × 102 to 2.34 × 102 colony-forming units with povidone-iodine (59%) and from 12.34 × 102 to 0.93 × 102 colony-forming units (82%) with chlorhexidine-ethanol. Infection rates with the use of povidone-iodine and chlorhexidine-ethanol groups were not significantly different (9.5 vs. 7.0; p = 0.364). The reduction in colony counts in those who developed infection was only 15.6% compared with 77.1% in those who did not develop infection. Conclusions: The antibacterial efficacy of chlorhexidine-ethanol and povidone-iodine is comparable in open hernia repair.

Ventilator-associated pneumonia: role of colonizers and value of routine endotracheal aspirate cultures

OBJECTIVES To determine the role of colonizers in the causation of ventilator-associated pneumonia (VAP) and the value of routine pre-VAP endotracheal aspirate (EA) cultures in appropriately treating VAP. METHODS A prospective observational cohort study was conducted over a period of 15 months. Two hundred patients on mechanical ventilation for>48h were studied. RESULTS Acinetobacter spp (33.7%) and Pseudomonas spp (29.8%) were the most common colonizers. Of the 200 patients, 36 developed VAP. In 20 VAP patients, the pre-VAP EA culture-based strategy was not useful. However, in the remaining 16 VAP patients, a pre-VAP EA culture-based strategy would have appropriately treated 13 (81%; 95% confidence interval (CI) 62-100%), in comparison to only nine (56%; 95% CI 32-80%) by the American Thoracic Society (ATS) strategy. The seven patients in whom the ATS guidelines were inappropriate had Acinetobacter spp and Pseudomonas spp resistant to the higher antibiotics recommended by the ATS for multidrug-resistant pathogens. The positive predictive values of Pseudomonas aeruginosa, Acinetobacter baumannii, and methicillin-resistant Staphylococcus aureus (MRSA) isolated from pre-VAP EA cultures were 88%, 83%, and 100%, respectively. CONCLUSION VAP patients should be treated based on ATS guidelines, but whenever P. aeruginosa, A. baumannii, and MRSA are isolated from pre-VAP EA cultures, the initial antibiotic therapy should be extended to treat these.

Does single-dose preoperative dexamethasone minimize stress response and improve recovery after laparoscopic cholecystectomy?

Background Stress response after laparoscopic cholecystectomy (LC) is less compared with open cholecystectomy, but is still responsible for significant postoperative morbidity. Though preoperative glucocorticoids were found to be effective in reducing the response in open surgical procedures, their role in minimal access surgery is not clear. Aims and Objectives To evaluate the efficacy of single-dose preoperative dexamethasone in reducing the stress response and postoperative morbidity after LC. Materials and Methods In a prospective randomized, double-blind, placebo-controlled trial, 70 patients undergoing elective LC were randomized to receive either dexamethasone (8 mg intravenously), or placebo. The change in C-reactive protein levels after LC, pain scores at rest, and on exertion and narcotic requirements, the incidence and severity of postoperative nausea and vomiting (PONV), anti-emetic requirement, peak expiratory flow rate in both groups were compared. Results Dexamethasone was more effective in controlling late PONV (P=0.05). The antiemetic requirement was significantly less in the dexamethasone group (0.56 mg vs. 2.24 mg; P=0.02). Median pain scores were significantly less in the dexamethasone group at 24 hours at rest (P=0.002) and on exertion at 24 and 48 hours (P=0.03 and 0.001). Analgesic requirement was less in the test group (22.9 mg vs. 29.9 mg; P=0.054). The peak expiratory flow rate at 48 hours was higher in the dexamethasone group (315.28 vs. 285.8 l/min; P=0.04). The dexamethasone group showed significantly less elevation of C-reactive protein levels at 24 hours (7.17 μg/mL vs. 17.53 μg/mL; P=0.003) and 48 hours (10.65 μg/mL vs. 23.18 μg/mL; P=0.02) postoperatively. Conclusions Preoperative single-dose dexamethasone significantly reduces the pain scores, PONV, and antiemetic requirements while improving the respiratory function in the postoperative period after LC.

Acute osteomyelitis caused by Rhodococcus equi in an immunocompetent child.

Rhodococcus equi is an unusual pathogen causing infections mostly in immunocompromised patients, particularly in those with human immunodeficiency virus (HIV). It has rarely been reported to affect immunocompetent hosts, where it usually presents as an isolated extrapulmonary lesion. We report a case of osteomyelitis caused by this organism in an immunocompetent host.

Dermatitis cruris pustulosa et atrophicans revisited: our experience with 37 patients in south India.

Background  Dermatitis cruris pustulosa et atrophicans (DCPA) is a distinctive type of chronic superficial folliculitis, with a number of unique features such as its peculiar symmetric localization to legs, extreme chronicity, resistance to therapy, and inevitable alopecia and atrophy.

Reliability of Kirby-Bauer disk diffusion method for detecting meropenem resistance among non-fermenting gram-negative bacilli

BACKGROUND Meropenem is empirically used as a last resort for the treatment of infections by non-fermenting gram-negative bacilli (NFGNB). Minimum inhibitory concentration (MIC) determined using agar or broth dilution methods is widely used for testing meropenem resistance. However, it is not possible in resource-poor settings. AIM A prospective study was performed to evaluate the reliability of Kirby-Bauer disk diffusion (KBDD) method for detecting meropenem resistance among NFGNB. MATERIALS AND METHODS A total of 146 NFGNB consisting of 56 Acinetobacter baumannii, 24 Acinetobacter lwoffii, 48 Pseudomonas aeruginosa and 18 Pseudomonas spp. were included in the study. All the isolates were tested simultaneously by both KBDD method and agar dilution method. RESULTS Very major errors were not observed with A. baumannii, A. lwoffii and P. aeruginosa, while other Pseudomonas spp. showed a very major error rate of about 5.6%. The major error rates observed with A. baumannii, A. lwoffii, P. aeruginosa and Pseudomonas spp. were 1.8%, 0%, 2.1% and 28.6%, respectively. All the isolates showed a good correlation between zone diameters (KBDD method) and MICs (agar dilution method). The sensitivity and specificity of KBDD method for detecting meropenem resistance was above 90% for all the NFGNB except Pseudomonas spp. CONCLUSIONS The KBDD method can be reliably used for routine testing of meropenem resistance in A. baumannii, A. lwoffii and P. aeruginosa. However, further studies are needed before employing this technique for detecting meropenem resistance in Pseudomonas spp.

Melioidosis Presenting as Pseudomyxoma Peritonei: Yet Another Pretense of the Great Mimicker: An Unreported Entity

BACKGROUND Melioidosis, a lethal infectious disease caused by Burkholderia pseudomallei, an important human pathogen in tropical regions, is notorious for its diverse clinical presentations. METHODS We report a case of a 55-year-old woman with a history of total abdominal hysterectomy with bilateral salpingo-oophorectomy for ovarian mucinous cystadenocarcinoma five years back, who presented with complaints of chest pain, abdominal distention, and breathlessness for one week. Ultrasound-guided aspiration of the peritoneal free fluid revealed a thick gelatinous material consistent with pseudomyxoma peritonei. Cytologic analysis of the aspirate was negative for malignant cells, but bacterial culture proved positive for Burkholderia pseudomallei. RESULTS She was started on ceftazidime, and she improved symptomatically and was discharged on oral doxycycline and chloramphenicol after three weeks of intravenous antibiotic therapy. CONCLUSION This case is being reported to emphasize an unusual presentation of melioidosis and the significance of timely appropriate antibiotic therapy.

Screening for Intestinal Colonization with Vancomycin Resistant Enterococci and Associated Risk Factors among Patients Admitted to an Adult Intensive Care Unit of a Large Teaching Hospital

INTRODUCTION Gut colonization with Vancomycin Resistant Enterococci (VRE) increases the risk of acquiring infection during hospital stay. Patients admitted in the ICUs are the major reservoirs for VRE colonization due to higher antibiotic pressure. AIM To determine the rate of VRE colonization among patients admitted in the Medical Intensive Care Unit (MICU) and to assess the various risk factors which are associated with VRE colonization. MATERIALS AND METHODS This was a prospective study carried out over a period of 18 months from September 2013 to February 2015 in the Jawaharlal Institute of Post graduate Medical Education and Research (JIPMER), Pondicherry, South India. After 48 hours of ICU admission rectal swabs were collected from a total of 302 patients, admitted in MICU. The samples were inoculated on to Bile Esculin Sodium Azide agar with 6mg/L of vancomycin. Vancomycin resistance was confirmed by determination of Minimum Inhibitory Concentration (MIC) by agar dilution method. Isolates were identified up to species level by standard biochemical tests. Vancomycin resistance genes such as van A, van B and van C, were detected by Polymerase Chain Reaction (PCR). Risk factors were assessed by multivariate logistic regression analysis. RESULTS The rates of VRE colonization in patients admitted to MICU was 29%. Majority of the isolates were Enterococcus faecium (77.2 %) followed by Enterococcus faecalis (23.8%). All the VRE isolates were positive for van A gene. Increased duration of hospital stay, younger age, consumption of ceftriaxone and vancomycin were found to be significantly associated with VRE colonization in MICU. Among VRE colonized patients, six (4.5%) acquired VRE infection. CONCLUSION The rates of VRE colonization in our ICU were similar to other hospitals worldwide. Educating health care workers on the importance of adherence to hand hygiene is essential to bring down VRE colonization rates.

Molecular characterisation of antimicrobial resistance in Pseudomonas aeruginosa and Acinetobacter baumannii during 2014 and 2015 collected across India

Background: Surveillance of antimicrobial resistance (AMR) is of great importance. Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens and emergence of resistance in these have increased the morbidity and mortality rates. This surveillance study was initiated by the Government of India - Indian Council of Medical Research. The aim of this study is to determine the antimicrobial susceptibility profile and to characterise the enzyme mediated antimicrobial resistance such as extended spectrum beta-lactamases (ESBLs) and carbapenemases among multidrug-resistant (MDR) P. aeruginosa and A. baumannii. Materials and Methods: A multi-centric study was conducted from January 2014 to December 2015 with a total number of 240 MDR P. aeruginosa and 312 MDR A. baumannii isolated from blood, cerebrospinal fluid, respiratory, pus, urine and intra-abdominal infections. Kirby–Bauer disc diffusion was done to determine the antimicrobial susceptibility profile. Further, MDR isolates were characterised by multiplex polymerase chain reaction to determine the resistance genes for ESBLs and carbapenemases. Results: Among the ESBLs, blaVEB (23%), blaTEM (5%) and blaSHV (0.4%) in P. aeruginosa and blaPER (54%), blaTEM (16%) and blaSHV (1%) in A. baumannii were the most prevalent. Likewise, blaVIM (37%), blaNDM (14%), blaGES (8%) and blaIMP (2%) in P. aeruginosa and blaOXA-23like (98%), blaOXA-58like (2%), blaNDM (22%) and blaVIM (3%) in A. baumannii were found to be the most prevalent carbapenemases. blaOXA-51like gene, intrinsic to A. baumannii was present in all the isolates tested. Conclusion: The data shown highlight the wide difference in the molecular mechanisms of AMR profile between P. aeruginosa and A. baumannii. In P. aeruginosa, plasmid-mediated mechanisms are much lesser than the chromosomal mediated mechanisms. In A. baumannii, class D oxacillinases are more common than other mechanisms. Continuous surveillance to monitor the trends in AMR among MDR pathogens is important for implementation of infection control and to guide appropriate empirical antimicrobial therapy.