Biomedical subjects

Kay-Leong Khoo

Publications and source records attributed to Kay-Leong Khoo.

5 recordsLinked to original sources

PubMed2006

EUS-guided FNA immediately after unrevealing transbronchial needle aspiration in the evaluation of mediastinal lymphadenopathy: a prospective study.

BACKGROUND: Transbronchial needle aspiration (TBNA) and EUS-guided FNA (EUS-FNA) are minimally invasive diagnostic approaches to mediastinal lymphadenopathy. Rapid on-site cytopathologic evaluation (ROSE) may facilitate the decision whether to proceed to a second procedure in the same session. The aim of this study was to determine the utility of TBNA with ROSE, combined with the option for immediate EUS-FNA in a single-session approach to mediastinal lymphadenopathy. METHODS: We prospectively recruited 20 patients (12 men; mean age 66.7 +/- 10.2 years) with mediastinal lymphadenopathy on CT who required cytopathologic evaluation. Bronchoscopy was first performed with TBNA and ROSE. If this was unrevealing, EUS-FNA was performed immediately afterward with ROSE. All procedures were performed with the patient under local anesthesia and sedation. RESULTS: TBNA specimens were deemed adequate on-site in 13 patients, and EUS-FNA was performed in the remaining 7 patients. TBNA with ROSE was falsely negative in one patient. The diagnostic yield for TBNA and EUS-FNA alone was 65% and 86%, respectively. This single-session approach provided a yield of 90%, with no complications. The final diagnoses were 12 non-small-cell lung cancer, two small-cell lung cancer, one metastatic adenocarcinoma, two sarcoidosis, one tuberculosis, one lymphoma, and one with no definitive diagnosis. CONCLUSIONS: Combining TBNA with the option for EUS-FNA immediately after unrevealing TBNA gave a yield approaching that of mediastinoscopy and, therefore, may reduce the need for invasive mediastinal sampling. This single-session endoscopic approach was safe, required only local anesthesia and sedation, was convenient, and obviated the need for patients to return for a second procedure.

Aged↗

PubMed2005

The changing face of healthcare worker perceptions on powered air-purifying respirators during the SARS outbreak.

OBJECTIVES: Before the advent of severe acute respiratory syndrome (SARS), use of the powered air-purifying respirator (PAPR) in the setting of pulmonary tuberculosis has been controversial. Data regarding health care worker (HCW) perceptions and problems encountered with the use of the PAPRs were lacking. METHODOLOGY: A questionnaire-based survey was conducted of HCWs who had used the PAPR in clinical practice during the SARS outbreak, when use of the PAPR was mandatory and widespread. Evaluations of the question of whether HCWs were receptive to the use of the PAPR and their perceptions of common problems that were encountered were made. Perceptions of comfort, ease of use, visual, hearing, breathing and speech impairment, perceived protection against SARS and usage preferences were recorded. RESULTS: Only a minority of respondents found the PAPR uncomfortable, despite some interference with communication. Despite its much higher cost, the majority (84%) preferred to use the PAPR rather than the N-95 respirator when treating suspected SARS patients. However, opinions were equally divided regarding its use when treating patients with pulmonary tuberculosis; with 51% being in favour. CONCLUSIONS: With the advent of highly contagious diseases that pose a major occupational hazard to HCWs, the use of the PAPR has become more acceptable in clinical practice.

Attitude of Health Personnel↗

PubMed2003

Feasibility of using low-volume tissue samples for gene expression profiling of advanced non-small cell lung cancers.

PURPOSE: The majority of patients with non-small cell lung cancer (NSCLC) present at an advanced clinical stage, when surgery is not a recommended therapeutic option. In such cases, tissues for molecular research are usually limited to the low-volume samples obtained at the time of diagnosis, usually via fine-needle aspiration (FNA). We tested the feasibility of performing gene expression profiling of advanced NSCLCs using amplified RNA from lung FNAs. EXPERIMENTAL DESIGN AND RESULTS: A total of 46 FNAs was tested, of which 18 yielded RNA of sufficient quality for microarray analysis. Expression profiles of these 18 samples were compared with profiles of 17 pairs of tumor and normal lung tissues that had been surgically obtained. Using a variety of unsupervised and supervised analytical approaches, we found that the FNA profiles were highly distinct from the normal samples and similar to the tumor profiles. CONCLUSIONS: We conclude that when RNA amplification is successful, gene expression profiles from NSCLC FNAs can determine malignancy and suggest that with additional refinement and standardization of sample collection and RNA amplification protocols, it will be possible to conduct additional and more detailed molecular analysis of advanced NSCLC using lung FNAs.

Biopsy, Needle↗

PubMed2003

Transbronchial needle aspiration: initial experience in routine diagnostic bronchoscopy.

BACKGROUND: Transbronchial needle aspiration (TBNA) has been shown to be useful not only for the diagnosis and staging of lung cancer, its most widely studied indication, but also for many of other clinical indications. Despite this, it remains largely underutilized, mainly because of concerns with poor yield, safety, lack of experience of the bronchoscopist, and lack of cytopathological support. OBJECTIVE: To study the clinical utility and yield of TBNA as an adjunct to other conventional procedures in diagnostic bronchoscopy at a centre that was relatively inexperienced with this technique, but where there was availability of rapid on-site evaluation (ROSE). Most of the major indications for TBNA in both malignant as well as benign disease were included. SETTING: University Teaching Hospital naïve to the procedure. PATIENT AND METHODS: Forty-five consecutive patients who underwent TBNA as part of diagnostic bronchoscopy during a 2-year study period. RESULTS: TBNA gave a yield of 65% for evaluation of mediastinal disease, both benign and malignant. The overall diagnostic utility for all indications was 71% and there were no complications. CONCLUSIONS: We conclude that TBNA is a useful and safe adjunct to diagnostic bronchoscopy in routine clinical practice. It has a satisfactory yield even with an inexperienced team, if used with ROSE.

Biopsy, Fine-Needle↗

PubMed2003

Role of clinical judgment in the application of a nucleic acid amplification test for the rapid diagnosis of pulmonary tuberculosis.

BACKGROUND: Several nucleic acid amplification (NAA) tests for Mycobacterium tuberculosis (MTB) have been licensed for the rapid diagnosis of active pulmonary tuberculosis (PTB) in respiratory secretions. There is uncertainty however regarding the practical application of these tests in clinical decision making. OBJECTIVE: To evaluate the utility of the COBAS AMPLICOR assay (Roche Diagnostics; Singapore) for MTB as applied by specialists for the rapid diagnosis of PTB in the routine clinical setting. DESIGN: A prospective study of consecutive patients suspected of PTB and tested with the AMPLICOR assay under the care of respiratory physicians. The final diagnosis was based on all relevant clinical information after at least 3 months of follow-up. Accuracy of the NAA test was compared with that of the initial expectant treatment. Expectant treatment was based on an integrated approach that incorporated clinical evaluation with results of direct smear and NAA tests. RESULTS: The incidence of PTB in 168 patients was 32%. The basis for expectant treatment of PTB was positive smear result in 47%, clinical suspicion in 26%, and positive AMPLICOR result in 23%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the AMPLICOR test were 77%, 100%, 99%, 90%, and 93%, respectively. In comparison, they were 96%, 97%, 94%, 98%, and 97%, respectively, for the integrated clinical approach. CONCLUSIONS: In the rapid diagnosis of PTB, the clinical judgment of specialists augmented the utility of the NAA test: (1) specialists selected patients with high-to-moderate pretest probabilities, (2) they commenced treatment promptly on a positive NAA test result, and (3) they were willing to start treatment in some patients on the basis of high clinical suspicion despite negative smear and negative NAA test results.

Adolescent↗