[Bronchoalveolar lavage for diagnosing pneumonia in mechanically ventilated patients]

Change in Antimicrobial Therapy Based on Bronchoalveolar Lavage Data Improves Outcomes in ICU Patients with Suspected Pneumonia

Flexible bronchoscopy (FB) is often performed in critically ill patients with suspected pneumonia. It is assumed that there will be an association with improved outcomes when bronchoalveolar lavage (BAL) data lead to a change in antimicrobial therapy. Methods. This study included a retrospective cohort of intensive care unit (ICU) patients who underwent FB for a diagnosis of suspected pneumonia. The study compared the outcome of patients in whom antimicrobial modification was carried out based on BAL reports versus those in whom it was not carried out. Cases where the procedure could not be completed or had incomplete records were excluded. The FB reports were accessed from the register maintained in the Department of Respiratory Medicine. The demographic details, clinical symptoms, laboratory investigations, and microbiological and radiology reports were recorded. Data on the antmicrobial therapy that the patients received during treatment and the outcome of the treatment were obtained from the case records and noted in the data collection form. Results. Data from a total of 150 patients admitted to the ICU, who underwent FB, were analyzed. The outcomes in the group where antimicrobial modification based on bronchoalveolar lavage (BAL) fluid reports was carried out versus the no-change group were as follows: expired 23, improved 82, unchanged 8 versus expired 12, improved 18, and unchanged 7 (p = 0.018); total duration of ICU stay 13.12 ± 10.61 versus 19.43 ± 13.4 days (p = 0.012); and duration from FB to discharge from ICU 6.33 ± 3.76 days versus 8.46 ± 5.99 (p = 0.047). The median total duration of ICU stay and clinical outcomes were significantly better in the nonintubated patients in whom BAL-directed antimicrobial modification was implemented. Distribution of microorganisms based on BAL reports was as follows: Acinetobacter baumanii 45 (30%), Klebsiella pneumoniae 37 (24.66%), Escherichia coli 9 (6%), and Pseudomonas aeruginosa 9 (6%). Conclusion. A change in antimicrobial therapy based on BAL data was associated with improved outcomes. The commonest bacterial isolate in the BAL fluid was Acinetobacter baumanii.

Microbiology of Ventilator-associated Pneumonia in a Tertiary Care Cancer Hospital

Background

Ventilator-associated pneumonia (VAP) is an important cause of healthcare-associated infections, resulting in prolonged hospitalization with increased morbidity and mortality. Knowledge of predominant local pathogens and their antimicrobial susceptibility patterns helps in selection of appropriate initial antibiotic therapy in these critical cases.

Aim and objective

The aim and objective of this study is to characterize the microbiology and antimicrobial susceptibility patterns of VAP isolates in a tertiary cancer center.

Materials and methods

This is a 4-year qualitative observational study carried out at a tertiary care cancer hospital in Mumbai. All nondirect bronchoalveolar lavage specimens from patients with a clinical suspicion of VAP sent from the critical care unit to the department of microbiology were processed as per standard laboratory procedures. All isolates were identified to species level and an antimicrobial susceptibility testing was performed by the Kirby–Bauer disk diffusion method and/or the VITEK 2 automated identification and susceptibility system, according to Clinical and Laboratory Standards Institute guidelines.

Results

The study comprised 1,074 patients: 710 (66.10%) men and 364 (33.90%) women. A total of 827 bacterial isolates were obtained with 780 (94.32%) gram-negative organisms and 47 (5.68%) gram-positive organisms; of which Acinetobacter baumannii (38.7%), Pseudomonas aeruginosa (17.5%), and Klebsiella pneumoniae (16.6%) were the commonest. Of gram-negative bacilli, multidrug-resistant organisms constituted 87.50% and were susceptible to colistin.

Conclusions

VAP is associated with pathogens, such as A. baumannii, P. aeruginosa, and K. pneumoniae in our setting. High rates of resistance to aminoglycosides, β-lactam-β-lactamase inhibitor combinations, and carbapenems were noted.

How to cite this article

Sangale A, Bhat V, Kelkar R, Biswas S. Microbiology of Ventilator-associated Pneumonia in a Tertiary Care Cancer Hospital. Indian J Crit Care Med 2021;25(4):421–428.

Pneumocystis pneumonia in a non-HIV patient on chronic corticosteroid therapy: a question of prophylaxis

A man in his late 50s with a history of membranoproliferative glomerulonephritis presented with fever and mild dyspnoea. He was HIV-negative and had been on corticosteroids as immunosuppression for 6 months prior to tapering them off 1 week before presentation. He was not taking prophylaxis for Pneumocystis jirovecii pneumonia. After unsuccessful treatment for community-acquired pneumonia, his condition worsened and he required intubation and mechanical ventilation. Full respiratory workup including bronchoscopy revealed P jirovecii as a source for the patient's infection. He was treated successfully with a 21-day course of trimethoprim-sulfamethoxazole  and eventually weaned off the ventilator. He has had no complications to date. In our review of this case and the existing literature, we believe that proper utilisation of prophylaxis for pneumocystis pneumonia may have prevented our patient's transfer to intensive care unit. In our article, we discuss this issue and explore current evidence for prophylaxis.

[Analysis of 208 flexible bronchoscopies performed in an intensive care unit]

OBJECTIVE

To describe the main indications, clinical results and complications associated with fibrobronchoscopy in the Intensive Care Unit (ICU).

DESIGN

A retrospective, single-center observational study was carried out. Setting. Seventeen beds in a medical/surgical ICU. Patients. Consecutive patients undergoing fibrobronchoscopy during their stay in the ICU over a period of 5 years.

INTERVENTIONS

Flexible bronchoscopy performed by an intensivist. Main variables of interest. Flexible bronchoscopy indications and complications derived from the procedure.

RESULTS

A total of 208 flexible bronchoscopies were carried out in 192 patients admitted to the ICU. Most of the procedures (193 [92.8%]) were performed in mechanically ventilated patients. The average patient age was 58 ± 16 years, with an APACHE II score at admission of 19 ± 7. The most frequent indication for flexible bronchoscopy was diagnostic confirmation of initially suspected pneumonia (148 procedures), with positive bronchoalveolar lavage findings in 46%. The most frequent therapeutic indication was the resolution of atelectasis (28 procedures). Other indications were the diagnosis and treatment of pulmonary hemorrhage, the aspiration of secretions, control of percutaneous tracheotomy, and difficult airway management. The complications described during the procedures were supraventricular tachycardia (3.8%), transient hypoxemia (6.7%), and slight bleeding of the bronchial mucosal membrane (2.4%).

CONCLUSIONS

A microbiological diagnosis of pneumonia and the resolution of atelectasis are the most frequent indications for flexible bronchoscopy in critically ill patients. Flexible bronchoscopy performed by an intensivist in ICU is a safe procedure.

Comparison of bronchoscopic and non-bronchoscopic techniques for diagnosis of ventilator associated pneumonia

Background:

The diagnosis of ventilator associated pneumonia (VAP) remains a challenge because the clinical signs and symptoms lack both sensitivity and specificity and the selection of microbiologic diagnostic procedure is still a matter of debate.

Aims and Objective:

To study the role of various bronchoscopic and non-bronchoscopic diagnostic techniques for diagnosis of VAP.

Settings and Design:

This prospective comparative study was conducted in a medical ICU of a tertiary care center.

Materials and Methods:

Twenty-five patients, clinically diagnosed with VAP, were evaluated by bronchoscopic and non-bronchoscopic procedures for diagnosis. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of various bronchoscopic and non-bronchoscopic techniques were calculated, taking clinical pulmonary infection score (CPIS) of ≥6 as reference standard.

Results:

Our study has shown that for the diagnosis of VAP, bronchoscopic brush had a sensitivity, specificity, PPV and NPV of 94.9% [confidence interval (CI): 70.6–99.7], 57.1% (CI: 13.4–86.1), 85% (CI: 61.1–96) and 80% (CI: 21.9–98.7), respectively. Bronchoscopic bronchoalveolar lavage (BAL) had a sensitivity, specificity, PPV and NPV of 77.8% (CI: 51.9–92.6), 71.8% (CI: 24.1–94), 87.3% (CI: 60.4–97.8) and 55.5% (CI: 17.4–82.6), respectively. Sensitivity, specificity, PPV and NPV for non–bronchoscopic BAL (NBAL) were 83.3% (CI: 57.7–95.6), 71.43% (CI: 24.1–94), 88.2% (CI: 62.3–97.4) and 62.5% (CI: 20.2–88.2), respectively. Endotracheal aspirate (ETA) yield was only 52% and showed poor concordance with BAL (κ-0.351; P-0.064) and NBAL (k-0.272; P-0.161). There was a good microbiologic concordance among different bronchoscopic and non-bronchoscopic distal airway sampling techniques.

Conclusion:

NBAL is an inexpensive, easy, and useful technique for microbiologic diagnosis of VAP. Our findings, if verified, might simplify the approach for the diagnosis of VAP.