Multi-omics Analyses Reveal Synergistic Carbohydrate Metabolism in Streptococcus mutans-Candida albicans Mixed-Species Biofilms

Candida albicans, a major opportunistic fungal pathogen, is frequently found together with Streptococcus mutans in dental biofilms associated with severe childhood caries (tooth decay), a prevalent pediatric oral disease. However, the impact of this cross-kingdom relationship on C. albicans remains largely uncharacterized. Here, we employed a novel quantitative proteomics approach in conjunction with transcriptomic profiling to unravel molecular pathways of C. albicans when cocultured with S. mutans in mixed biofilms. RNA sequencing and iTRAQ (isobaric tags for relative and absolute quantitation)-based quantitative proteomics revealed that C. albicans genes and proteins associated with carbohydrate metabolism were significantly enhanced, including sugar transport, aerobic respiration, pyruvate breakdown, and the glyoxylate cycle. Other C. albicans genes and proteins directly and indirectly related to cell morphogenesis and cell wall components such as mannan and glucan were also upregulated, indicating enhanced fungal activity in mixed-species biofilm. Further analyses revealed that S. mutans-derived exoenzyme glucosyltransferase B (GtfB), which binds to the fungal cell surface to promote coadhesion, can break down sucrose into glucose and fructose that can be readily metabolized by C. albicans, enhancing growth and acid production. Altogether, we identified key pathways used by C. albicans in the mixed biofilm, indicating an active fungal role in the sugar metabolism and environmental acidification (key virulence traits associated with caries onset) when interacting with S. mutans, and a new cross-feeding mechanism mediated by GtfB that enhances C. albicans carbohydrate utilization. In addition, we demonstrate that comprehensive transcriptomics and quantitative proteomics can be powerful tools to study microbial contributions which remain underexplored in cross-kingdom biofilms.

The clinical utility of Xpert® MTB/RIF testing in induced sputum

We performed a prospective clinical audit in hospitalised patients with suspected pulmonary tuberculosis (PTB) with the objective of evaluating the accuracy and clinical utility of Xpert® MTB/RIF in induced sputum in an intermediate-burden setting. Of 450 patients audited, 61 (13.6%) were diagnosed with PTB based on positive culture. The sensitivity, specificity and positive and negative predictive values for Xpert in smear-negative cases for induced sputum were respectively 75%, 99.5%, 94.7% and 97.0%. Xpert in induced sputum may facilitate diagnostic yield and expedite treatment in up to a quarter of PTB patients.

From ICU to Emergency Department: 9-Year Experience with Non-Invasive Ventilation for COPD

Introduction

Non-invasive ventilation (NIV) has been shown to be beneficial for chronic obstructive pulmonary disease (COPD) patients with persistent respiratory acidosis during acute exacerbations. This clinical study described the experience of implementing an NIV program in the emergency department for COPD patients.

Methods

In the pre-implementation phase, patients who presented to the emergency department were transferred to the intensive care unit for NIV. Following the NIV program, patients had NIV commenced in the emergency department. We reported the change in hospital outcomes pre and post-implementation.

Results

A total of 153 patients received NIV, 34 in the pre-implementation phase and 119 patients in the post-implementation phase. The mean pH was 7.22±0.07 and the Acute Physiology and Chronic Health Evaluation (APACHE) II score was 18.9±4. Hospital mortality was lower in the post-implementation phase (1.7% versus 11.8%; p=0.008). The median door-to-NIV time was shorter in the post-implementation phase (64 minutes; interquartile range [IQR] 35-113) versus (457 minutes; IQR 143-1320).

Conclusions

NIV program in the emergency department is feasible and is associated with better hospital outcomes in patients with COPD. (Hong Kong j.emerg.med. 2014;21:140-147)

Is a short arm cast appropriate for stable distal radius fractures in patients older than 55 years? A randomized prospective multicentre study

We conducted a prospective randomized, multicentre study to compare short arm and long arm plaster casts for the treatment of stable distal radius fracture in patients older than 55 years. We randomly assigned patients over the age of 55 years who had stable distal radius fracture to either a short arm or long arm plaster cast at the first review 1 week after their injury. Radiographic and clinical follow-up was conducted at 1, 3, 5, 12 and 24 weeks following their injury. Also, degree of disability caused by each cast immobilization was evaluated at the patient's visit to remove the cast. There were no significant differences in radiological parameters between the groups except for volar tilt. Despite these differences in volar tilt, neither functional status as measured by the Disabilities of the Arm, Shoulder and Hand, nor visual analogue scale was significantly different between the groups. However, the mean score of disability caused by plaster cast immobilization and the incidence rate of shoulder pain were significantly higher in patients who had a long plaster cast. Our findings suggest that a short arm cast is as effective as a long arm cast for stable distal radius fractures in the elderly. Furthermore, it is more comfortable and introduces less restriction on daily activities.

LEVEL OF EVIDENCE

II.

Cibotium barometz

Cibotium barometz plant habit

Short-term mortality among older persons hospitalized for pneumonia: influence of baseline patient characteristics beyond severity of illness

BACKGROUND

Although severity of illness indices such as pneumonia severity index (PSI) are good predictors of short-term mortality for community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP), other patient factors may have added prognostic value.

OBJECTIVE

To identify patient factors beyond the PSI which explain 30-day mortality among older persons hospitalized with CAP and HCAP.

DESIGN

Retrospective cohort study.

SETTING

Three acute care hospitals in Singapore in 2007.

PATIENTS

Hospitalized adults aged 65 years or older who have primary International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) codes 480 to 486 with clinical and radiological features of pneumonia.

INTERVENTIONS

None.

MEASUREMENTS

Thirty-day mortality, PSI class, demographic and clinical features, comorbid conditions, functional status, selected laboratory tests, and chest radiographic findings.

RESULTS

Among 1607 patients included, 890 (55.4%) had CAP and 717 (44.6%) had HCAP. After adjustment for PSI class in logistic regression analyses, pre-morbid ambulation impairment (odds ratio [OR] 2.61, 95% confidence interval [CI] 1.98 to 3.45), hospitalization in the prior 30 days (OR 1.93, 95% CI 1.38 to 2.71), and absence of cough and purulent sputum (OR 1.47, 95% CI 1.14 to 1.90) were all significantly associated with 30-day mortality. These associations remained constant when CAP and HCAP were analyzed separately.

CONCLUSIONS

Recent hospitalization, pre-morbid ambulation impairment, and atypical presentation were independently associated with higher 30-day mortality among older persons hospitalized for pneumonia, after adjusting for severity of illness. These factors could be considered in addition to PSI when performing risk stratification and adjustment in this setting.

Utility of the electronic information resource UpToDate for clinical decision-making at bedside rounds

INTRODUCTION

Clinical questions often arise at daily hospital bedside rounds. Yet, little information exists on how the search for answers may be facilitated. The aim of this prospective study was, therefore, to evaluate the overall utility, including the feasibility and usefulness of incorporating searches of UpToDate, a popular online information resource, into rounds.

METHODS

Doctors searched UpToDate for any unresolved clinical questions during rounds for patients in general medicine and respiratory wards, and in the medical intensive care unit of a tertiary teaching hospital. The nature of the questions and the results of the searches were recorded. Searches were deemed feasible if they were completed during the rounds and useful if they provided a satisfactory answer.

RESULTS

A total of 157 UpToDate searches were performed during the study period. Questions were raised by all ranks of clinicians from junior doctors to consultants. The searches were feasible and performed immediately during rounds 44% of the time. Each search took a median of three minutes (first quartile: two minutes, third quartile: five minutes). UpToDate provided a useful and satisfactory answer 75% of the time, a partial answer 17% of the time and no answer 9% of the time. It led to a change in investigations, diagnosis or management 37% of the time, confirmed what was originally known or planned 38% of the time and had no effect 25% of the time.

CONCLUSION

Incorporating UpToDate searches into daily bedside rounds was feasible and useful in clinical decision-making.

Diagnostic characteristics of clinical prediction models for obstructive sleep apnea in different clinic populations

PURPOSE

As predictive factors and their diagnostic values are affected by the characteristics of the population studied, clinical prediction model for obstructive sleep apnea (OSA) may exhibit different diagnostic characteristics in different populations. We aimed to compare the diagnostic characteristics of clinical prediction models developed in two different populations.

METHODS

One hundred seventeen consecutive clinic patients (group 1) were evaluated to develop a clinical prediction model for OSA (local model). The diagnostic characteristics of this local model were compared with those of a foreign model by applying both models to another group of 52 patients who were referred to the same clinic (group 2). All patients underwent overnight polysomnography.

RESULTS

The local model had an area under receiver operator characteristics curve of 79%. A cutoff of 0.6 was associated with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 77.9%, 72.5%, 84.5%, and 63.0%, respectively. The overall diagnostic accuracy, sensitivity, specificity, PPV, and NPV of the local model using data from patients in group 2 were 69.0%, 78.1%, 45.0%, 69.4%, and 56.3%, respectively. The foreign model had an overall diagnostic accuracy of 64.0% when applied to data from patients in group 2. At the optimal cutoff of 17, the foreign model was associated with sensitivity of 38.2%, specificity of 83.3%, NPV of 41.7% and PPV of 81.3%.

CONCLUSIONS

Clinical prediction model for OSA derived from a foreign population exhibits markedly different diagnostic characteristics from one that is developed locally, even though the overall accuracy is similar. Our findings challenge the predictive usefulness and the external validity of clinical prediction models.

Metered-dose inhaler with spacer instead of nebulizer during the outbreak of severe acute respiratory syndrome in Singapore

BACKGROUND

The use of metered-dose inhaler (MDI) with spacer instead of nebulizer may be important during an outbreak of an airborne infection. However, there is a paucity of data on patients' and nurses' abilities and perspectives on MDI with spacer for the treatment of acute airway obstruction during such an outbreak.

METHODS

We evaluated 50 consecutive MDI-with-spacer treatments administered in the respiratory wards of the National University Hospital of Singapore, and interviewed the patients after each treatment during the outbreak of severe acute respiratory syndrome (SARS). We also conducted interviews with 50 nurses who had experience in administering bronchodilators via both nebulizer and MDI with spacer.

RESULTS

Forty-six patients (92%) were able to use MDI with spacer effectively. Sixteen percent of the patients preferred nebulizer over MDI with spacer. Fifty-eight percent of the patients thought MDI with spacer was easier to use than nebulizer, and 34% thought MDI was as easy to use as nebulizer. Sixteen percent of the patients thought that nebulizer was more effective than MDI with spacer in relieving their symptoms. Ninety-six percent of the nurses preferred nebulizer over MDI with spacer. Forty-two nurses (84%) thought that nebulizer was more effective for treating acute airflow obstruction in the hospital.

CONCLUSIONS

In the in-patient setting during an outbreak of an airborne infection, for treatment of acute airflow obstruction, MDI with spacer was acceptable and preferred by a high percentage of patients. However, a high percentage of nurses had misconceptions regarding the efficacy of and patients' ability to use MDI with spacer.

Effects of inhaled versus systemic corticosteroids on exhaled nitric oxide in severe acute asthma

BACKGROUND

There is a paucity of information on the differential effects of systemic versus inhaled corticosteroids on airway inflammation in patients with acute asthma. This study aimed to evaluate the effects of stopping systemic corticosteroids while maintaining the inhaled corticosteroids (ICS) on airway inflammation, lung function and asthma symptoms in patients who had been discharged from hospital after treatment for severe acute asthma.

METHODS

Twenty-four adult patients with severe exacerbations of asthma were treated with both oral and inhaled corticosteroids after discharge from hospital. Oral corticosteroids were stopped after 1 week. Spirometry, asthma quality of life questionnaire (AQLQ) score and exhaled nitric oxide (NO) were measured at discharge, 1 week, and 2 weeks after discharge.

RESULTS

Withdrawal of oral corticosteroids resulted in significant rebound in mean exhaled NO by 11.0ppb (95% CI, 4.9-17.1ppb, p<0.001) or 47.7% (95% CI, 22.4-73.1%) despite uninterrupted ICS treatment. The rebound in exhaled NO occurred despite significant improvement in the mean AQLQ score (p=0.006) and frequency of reliever use (p=0.003) and was not associated with significant change in the mean FEV(1) (p=0.64).

CONCLUSIONS

In patients discharged from hospital after treatment for asthma exacerbations, withdrawal of oral corticosteroids resulted in increase in exhaled NO levels despite continued ICS treatment.

Comparison of clinical with pathological nodal staging from systematic mediastinal lymph node dissection in early resectable non-small cell lung cancer

INTRODUCTION

We compared the accuracy of clinical nodal (cN) status N0-1 with that of pathological nodal (pN) status obtained from systematic mediastinal lymph node dissection (SMLD) in primary non-small cell lung cancer.

METHODS

Data from 22 consecutive patients, who underwent lung cancer resection and SMLD of at least three mediastinal lymph node stations, from November 2001 to May 2003, were ana1ysed retrospectively. Only patients with cN0-1 status on computed tomography (CT) referred for surgery, were included in this study.

RESULTS

Mean age of patients was 66.6 +/- 8.1 years with a male to female ratio of 17:5. Mean number of lymph node stations dissected was 5.8 +/- 1.8. 41 percent had squamous cell carcinoma, 45.5 percent had adenocarcinoma, and 4.5 percent each had large cell carcinoma, bronchioalveolar carcinoma or a lymphoepithelial carcinoma. pN2 metastases were found in 27.3 percent of patients. The sensitivity of cN0-1 was only 12.5 percent, with a specificity of 92.9 percent and an area under the receiver operating characteristics curve of 0.53. The positive and negative predictive values of cN0-1 status were 50 percent and 65 percent, respectively, with an accuracy of 59 percent. 41 percent of patients were understaged with 27.3 percent in pathological stage III. Curative resections were achieved in 59 percent of patients.

CONCLUSION

The sensitivity of cN0-1 status based on CT alone is extremely poor when compared with pN status from SMLD. Based on cN0-1 status alone without SMLD, 27.3 percent of patients in pN2 would have been understaged. We recommend that all patients with cN0-1 status should undergo SMLD of at least three appropriate mediastinal node stations, for more accurate staging.

Use of traditional versus electronic medical-information resources by residents and interns

BACKGROUND

Little is known about the information-seeking behaviour of junior doctors, with regard to their use of traditional versus electronic sources of information.

AIMS

To evaluate the amount of time junior doctors spent using various medical-information resources and how useful they perceived these resources to be.

METHODS

A questionnaire study of all residents and interns in a tertiary teaching hospital in July and August 2004.

RESULTS

In total, 134 doctors returned the completed questionnaires (response rate 79.8%). They spent the most time using traditional resources like teaching sessions and print textbooks, rating them as most useful. However, electronic resources like MEDLINE, UpToDate, and online review articles also ranked highly. Original research articles were less popular.

CONCLUSION

Residents and interns prefer traditional sources of medical information. Meanwhile, though some electronic resources are rated highly, more work is required to remove the barriers to evidence-based medicine.

Soluble triggering receptor expressed on myeloid cells-1 in acute respiratory infections

Levels of the soluble form of the triggering receptor expressed on myeloid cells (sTREM)-1 are elevated in severe sepsis. However, it is not known whether sTREM-1 measurements can distinguish milder bacterial infections from noninfectious inflammation. The present authors studied whether serum sTREM-1 levels differ in community-acquired pneumonia, exacerbations of chronic obstructive pulmonary disease (COPD), asthma and controls, and whether sTREM-1 may be used as a surrogate marker for the need for antibiotics. Serum sTREM-1 levels in 150 patients with pneumonia, COPD and asthma exacerbations and 62 healthy controls were measured. Serum sTREM-1 levels were significantly elevated in pneumonia (median 295.2 ng x mL(-1)), COPD (280.3 ng x mL(-1)) and asthma exacerbations (184.0 ng x mL(-1)) compared with controls (83.1 ng x mL(-1)). Levels were higher in pneumonia and Anthonisen type 1 COPD exacerbations than in type 2 and 3 COPD and asthma exacerbations. The area under the receiver operating characteristics curve for sTREM-1 as a surrogate marker for the need for antibiotics was 0.77. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 were elevated predominantly in pneumonia and Anthonisen type 1 COPD exacerbations versus type 2 and 3 chronic obstructive pulmonary disease exacerbations, asthma and controls. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 has moderate but insufficient accuracy as a surrogate marker for the need for antibiotics in lower respiratory tract infections.

Tuberculosis associated with Mycobacterium tuberculosis Beijing and non-Beijing genotypes: a clinical and immunological comparison

Background

The Mycobacterium tuberculosis Beijing genotype is biologically different from other genotypes. We aimed to clinically and immunologically compare human tuberculosis caused by Beijing and non-Beijing strains.

Methods

Pulmonary tuberculosis patients were prospectively enrolled and grouped by their M. tuberculosis genotypes. The clinical features, plasma cytokine levels, and cytokine gene expression levels in peripheral blood mononuclear cells (PBMC) were compared between the patients in Beijing and non-Beijing groups.

Results

Patients in the Beijing group were characterized by significantly lower frequency of fever (odds ratio, 0.12, p = 0.008) and pulmonary cavitation (odds ratio, 0.2, p = 0.049). Night sweats were also significantly less frequent by univariate analysis, and the duration of cough prior to diagnosis was longer in Beijing compared to non-Beijing groups (medians, 60 versus 30 days, p = 0.048). The plasma and gene expression levels of interferon (IFN) γ and interleukin (IL)-18 were similar in the two groups. However, patients in the non-Beijing group had significantly increased IL-4 gene expression (p = 0.018) and lower IFN-γ : IL-4 cDNA copy number ratios (p = 0.01).

Conclusion

Patients with tuberculosis caused by Beijing strains appear to be less symptomatic than those who have disease caused by other strains. Th1 immune responses are similar in patients infected with Beijing and non-Beijing strains, but non-Beijing strains activate more Th2 immune responses compared with Beijing strains, as evidenced by increased IL-4 expression.

Prospective study of a new serological test (ASSURE TB Rapid Test) for the diagnosis of pulmonary tuberculosis

OBJECTIVE

To prospectively compare a rapid tuberculosis serological test, ASSURE TB Rapid Test, with traditional smear and culture methods for the diagnosis of pulmonary tuberculosis (PTB).

DESIGN

All consecutive in-patients aged > or = 18 years suspected of having active PTB and admitted between June 2001 and March 2003 were tested with three sputum samples for smear and culture of Mycobacterium tuberculosis and serology (done within 3 days).

RESULTS

Of 238 patients initially enrolled (male: female 2.5:1, mean age 56.6 years), the final analysis included 216 patients. For the final diagnosis of PTB, the sensitivity and specificity of the serological test were respectively 60.2% (95%CI 50.5-69.1) and 82.3% (95%CI 74.2-88.2) compared to 53.4% (95%CI 43.8-62.7) and 98.2% (95%CI 93.8-99.5) for the smear test. A combination of smear and serology provided an increased sensitivity of 74.8% (95%CI 65.6-82.2), but a lower specificity of 80.5% (95%CI 72.3-86.8).

CONCLUSION

The new serological test showed a moderate increase in sensitivity but a decrease in specificity compared to smear examination. The combination (smear + serology) test further increased the sensitivity while maintaining a moderate specificity.

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.

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.

Noninvasive ventilation in hypercapnic acute respiratory failure due to chronic obstructive pulmonary disease vs. other conditions: effectiveness and predictors of failure

OBJECTIVE

This study compared the effectiveness of noninvasive ventilation (NIV) and the risk factors for NIV failure in hypercapnic acute respiratory failure (ARF) due to chronic obstructive pulmonary disease (COPD) vs. non-COPD conditions.

DESIGN AND SETTING

Prospective cohort study in the medical intensive care unit of a university hospital.

PATIENTS AND PARTICIPANTS

111 patients with hypercapnic ARF, 43 of whom had COPD exacerbations and 68 other conditions. Baseline characteristics of the two groups were similar.

MEASUREMENTS AND RESULTS

The risk of NIV failure, defined as the need for endotracheal intubation, was significantly lower in COPD than in other conditions (19% vs. 47%). High APACHE II score was an independent predictor of NIV failure in COPD (OR 5.38 per 5 points). The presence of pneumonia (OR 5.63), high APACHE II score (OR 2.59 per 5 points), rapid heart rate (OR 1.22 per 5 beats/min), and high PaCO(2) 1 h after NIV (OR 1.22 per 5 mmHg) were independent predictors of NIV failure in the non-COPD group. Failure of NIV independently predicted mortality (OR 10.53).

CONCLUSIONS

Noninvasive ventilation was more effective in preventing endotracheal intubation in hypercapnic ARF due to COPD than non-COPD conditions. High APACHE II score predicted NIV failure in both groups. Noninvasive ventilation was least effective in patients with hypercapnic ARF due to pneumonia.

A prospective audit of referrals for breathlessness in patients hospitalised for other reasons

INTRODUCTION

This prospective audit examines the diagnostic and clinical outcomes of consecutive adult inpatients who were admitted to a university hospital for other reasons and referred for breathlessness to respiratory physicians.

METHODS

We enrolled all adult inpatients referred for breathlessness from May 2000 to October 2001. We evaluated the clinical features and utility of routine investigations, such as blood tests and radiology. Subsequent investigations were undertaken at the discretion of the physician.

RESULTS

Of the 105 patients, 49 were men and 56 were women. Their mean age was 66 plus or minus 18 years. Surgical departments and cardiology were the main referring departments. Respiratory infection (31 percent) was the most common diagnosis. Acute pulmonary embolism (PE) was diagnosed in four patients postoperatively. Chest radiographs were helpful in making a diagnosis in 66 percent of patients. Computed tomography pulmonary angiogram of the thorax was performed in 31 of the 34 patients who were investigated for acute PE. More postoperative than non-postoperative patients were tested for PE (p-value less than 0.0001).

CONCLUSION

In hospitalised patients referred for breathlessness, respiratory infections were the most common diagnosis and the chest radiograph was the most useful initial investigation. Computed tomography pulmonary angiogram was the preferred investigation for acute PE and clinicians were more inclined to investigate for PE in postoperative patients.

Pulmonary hypereosinophilia

INTRODUCTION

Eosinophilic lung diseases are a diverse group of pulmonary disorders linked by the common finding of increased eosinophilia in blood and/or tissue. They usually present to the clinician as pulmonary infiltrates with eosinophilia for which the differential diagnoses is fairly broad.

CLINICAL PICTURE

Three patients presented with subacute cough, pulmonary infiltrates and a markedly elevated eosinophil count >1.5 x 109/L. Each case exemplifies its clinical peculiarities and pearls and illustrates the diversity in this group of disorders.

TREATMENT

A common theme in the approach to its management is excluding infection before proceeding with therapy, often with steroids.

OUTCOME

There is often a dramatic response to steroid therapy with resolution of symptoms and chest radiographic findings.

CONCLUSION

The arbitrary label of "pulmonary hypereosinophilia" enables the differential diagnoses to be narrowed to the 4 main categories of infections with parasites or fungus, the Churg-Strauss syndrome, chronic eosinophilic pneumonia and the idiopathic hypereosinophilic syndrome.

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.

Singapore's experience of SARS

The coronavirus that causes severe acute respiratory syndrome (SARS) is transmitted mainly via respiratory droplets. Typical presenting symptoms are akin to those of ordinary pneumonia. Young patients start with fever, chills, malaise, headache, or myalgia; cough and dyspnoea follow. Older persons and those taking corticosteroids may have neither fever nor respiratory symptoms. Exceptional suspicion is needed to identify SARS early in the illness. During an outbreak, even patients with low suspicion of SARS should be promptly isolated, and all contacts quarantined. Health workers need training in the use of appropriate barriers against droplets and other body fluids. Any fever cluster in patients or carers requires immediate action: discharges, visits, and transfers between wards and hospitals should be stopped. Halting hospital admissions and ten-day quarantine of suspected cases create wide buffer zones. To counter a possible resurgence of SARS, a system of prepared isolation and quarantine facilities is important.

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.

Prescribing and administration of nebulized bronchodilators: a prospective audit in a university hospital

OBJECTIVE

Inaccurate and incomplete prescribing of nebulized bronchodilators can result in uncertainty and suboptimal treatment. A prospective study was carried out to assess the completeness of prescription and the quality of bronchodilator drug administration via nebulizers.

METHODOLOGY

A total of 121 consecutive inpatient nebulized bronchodilator prescriptions and treatments administered to 93 adult medical inpatients in a university hospital were studied prospectively. Five different aspects of the prescriptions were examined to assess their accuracy and completeness. The administration of each nebulizer treatment was studied using audit of medication charts and interview with ward nurses.

RESULTS

No prescription was correct and complete in all five aspects assessed. The most common mistake was failure to state the type and flow rate of driving gas (100%). This was followed by failure to prescribe recommended doses of bronchodilators (46%) and failure to give unambiguous instruction on frequency of treatment (39%). It was found that in only 21.5% of instances was the administration of nebulized bronchodilator drugs optimal.

CONCLUSION

This prospective audit has demonstrated major deficiencies in the prescribing and administration of nebulized bronchodilators and it has highlighted the need for a local protocol and continuing staff education. The alternative method of administering bronchodilator via metered dose inhaler with large volume spacer should be evaluated in the treatment of acute airflow obstruction in hospitalized patients.

What is the optimal approach for using a direct amplification test in the routine diagnosis of pulmonary tuberculosis? A preliminary assessment

OBJECTIVE

The aim of this study was to determine the most appropriate strategy for the rapid diagnosis of pulmonary tuberculosis (PTB) using a nucleic acid amplification (NAA) test.

METHODOLOGY

This was a prospective study of 128 adult patients in whom respiratory secretions were tested for Mycobacterium tuberculosis by the AMPLICOR assay. The basis for starting PTB treatment was noted for each patient. The optimal approach was determined by using Bayes' theorem to compare different combinations of pretest probability, smear results with the AMPLICOR test.

RESULTS

The incidence of PTB was 15.6%. In only one patient was treatment for PTB commenced because of a positive AMPLICOR result. The rest were managed according to the conventional approach which relied upon clinical judgment and direct smear. The optimal approach was to treat patients with high or intermediate pretest risk for PTB who returned positive AMPLICOR tests. The overall accuracies of the conventional approach, AMPLICOR test and optimal approach were 89.8, 95.3 and 96.1%, respectively.

CONCLUSION

This small study suggests that NAA testing be limited to patients with high or intermediate pretest risk of PTB. In this group, positive results demand treatment while the management of those with negative results still relies on clinical judgment.

The pattern of utilisation and accuracy of a commercial nucleic acid amplification test for the rapid diagnosis of Mycobacterium tuberculosis in routine clinical practice

BACKGROUND

Several nucleic acid amplification (NAA) tests are available for the rapid detection of Mycobacterium tuberculosis (MTB) in clinical specimens.

AIMS

To identify the pattern of utilisation and accuracy of the AMPLICOR test in routine clinical practice in an acute care setting.

DESIGN

A retrospective descriptive study.

METHOD

We studied 159 consecutive specimens in which the AMPLICOR (Roche; Branchburg, NJ) test was requested by attending doctors. The sensitivities and specificities of the AMPLICOR for detection of active tuberculosis (TB) were calculated in relation to types of specimens, smear and culture results.

RESULTS

The number of requests more than doubled from 1999 to 2000. Thirty-eight percent of the specimens were not from the respiratory tract. The majority of the specimens had requests for one or more additional test (mean 1.8). The rate of active TB was 18%. The sensitivities of the AMPLICOR on per specimen, per patient, per smear negative specimen and per smear negative patient basis were found to be 81%, 80%, 66.7% and 71.4% respectively. The specificities for these groups accordingly were 99%, 98.6%, 99% and 98.6% respectively. The sensitivity and specificity for respiratory specimens were 97.5% and 98.5%, while for non-respiratory specimens, they were 60% and 100%. In smear negative specimens, the sensitivity and specificity for respiratory specimens were 60% and 98.5%, while for non-respiratory specimens, they were 75% and 100%. The AMPLICOR assay was negative in all 21 specimens of pleural or spinal fluid.

CONCLUSIONS

There is a growing demand for NAA in the rapid diagnosis of TB with a high proportion of non-respiratory specimens. The number of additional diagnostic tests performed on each specimen should be limited. In routine clinical practice, the AMPLICOR assay is a useful confirmatory test for active pulmonary TB. The utility of the AMPLICOR assay for MTB detection in exudative fluid specimens needs further evaluation.

Emergency department asthma: compliance with an evidence-based management algorithm

BACKGROUND

Recent surveys in emergency medicine departments show inadequacies in many aspects of acute asthma management.

OBJECTIVE

The objective of this study was to evaluate the adherence to management algorithm for acute asthma in the emergency department which focused on evidence-based treatment steps rather than documentation and patient classification.

METHODS

A retrospective audit of consecutive adult patients with acute exacerbations of asthma in the emergency medicine department of a university hospital managed in the context of a clinical algorithm.

RESULTS

We collated information from 344 episodes of acute asthma (94% of total) over a 4-month period. The first-line treatment was nebulised bronchodilators in 97%, combination of salbutamol and ipratropium bromide in 93% and the combination in recommended dosages in 87%. Systemic corticosteroid treatment was administered to 82% of patients. A further course of systemic corticosteroid was prescribed at discharge for 94% of patients. Overall, 93% of patients received some form of systemic corticosteroid treatment. The admission rate was 35.2%, and was significantly higher in women and the elderly. Of those who were admitted, 46.2% received > or = 3 nebulised treatments and 69% received intravenous hydrocortisone.

CONCLUSIONS

In the management of acute asthma, we found excellent compliance with specific treatment steps based upon clinical evidence. However, adherence to second-line treatment was less satisfactory. Nevertheless, whenever second-line treatment was complied with, reasonable outcomes were achieved. It may be more appropriate to emphasise evidence-based treatment rather than extensive documentation.