Search PubMed⌕ Search

Biomedical subjects

T K Lim

Publications and source records attributed to T K Lim.

At least 73 records · Page 4Linked to original sources
PubMed1996

Treatment of severe exacerbation of chronic obstructive pulmonary disease with mask-applied continuous positive airway pressure.

The efficacy of mask-applied continuous positive airway pressure (CPAP) in the treatment of patients with acute severe exacerbations of chronic obstructive pulmonary disease (COPD) was examined. Ten patients with severe exacerbation of COPD who had deteriorated during conventional therapy were treated with face-mask delivered CPAP (+5 cmH2O; Downs Vital signs Inc., New Jersey, USA) instead of tracheal intubation and mechanical ventilation. The patients that were selected required mental alertness, intact upper airway reflexes, the clinical signs of dynamic hyperinflation and a positive end-expiratory pressure auto-(PEEP) manifested as expiratory wheeze and grunting. Nine out of 10 patients responded promptly to mask-CPAP with less distress, better oxygenation, lower respiratory and pulse rates. There was no significant change in arterial carbon dioxide tension with mask-CPAP treatment. One patient deteriorated on mask-CPAP and required intubation and mechanical ventilation. Three patients died (none of these patients died during the acute period of exacerbation). It was concluded that Mask-CPAP may be an alternative to mechanical ventilation in the treatment of selected patients with severe hypercapnic exacerbations of COPD.

Aged↗
PubMed1996

A profile of acute asthma patients presenting to the emergency room.

We conducted a three-month prospective study on the profile of 70 acute adult asthmatic patients presenting to the Accident and Emergency Unit of a general hospital. The overall background asthmatic activity, clinical features of current exacerbation, maintenance drug treatment, gross psycho-social problems, previous experience of near-fatal asthma, and admission and relapse rates were documented. Ninety percent of the presentations were within 24 hours of the initial attack, with an average pre-hospital therapy duration of 6.5 hours. Sixty-seven percent sought further treatment after failure to find relief from their salbutamol metered-dose inhalers. Sixteen percent did not receive any treatment before presentation. Ten percent gave a past history of mechanical ventilation for severe or near fatal asthma. The majority (94%) had asthmatic symptoms in the mild to moderate range. About half (46%) had attended the Emergency Room (ER) at least once in the previous six months. On average, patients were on two items of drugs and 23% were on maintenance inhaled steroids. One-third (33%) of the patients were found to have psycho-social problems relating to their condition. The admission rate was 37% with relapse rate following ER discharge of 13%. The study showed a high proportion of patients with psycho-social problems relating to asthma, and a subset of patients with frequent visits to the ER. It also revealed the infrequent use of prophylactic therapy.

Acute Disease↗
PubMed1996

Severe community-acquired pneumonia in Singapore.

BACKGROUND: There has been no previous study documenting the aetiology and prognosis of severe community-acquired pneumonia in Singapore. Patients with severe community-acquired pneumonia (SCAP) needing admission to a medical intensive care unit in Singapore were studied retrospectively. METHODS: All patients admitted to the medical intensive care unit at National University Hospital from June 1991 to February 1993 with a diagnosis of community-acquired pneumonia were entered into the study. All patients had blood cultures, sputum cultures, serologies for Legionella and mycoplasma drawn on admission. APACHE II scores were determined prospectively. RESULTS: Fifty-nine consecutive cases from June 1991 to February 1993 were identified with a mean age of 61 (SD 17) years. Nearly all the cases needed mechanical ventilation (90%) and overall mortality was 63%. An aetiological agent was identified in the majority of cases (68%), with Klebsiella pneumoniae being the most common agent (9 cases, 15%). Haemophilus influenzae and Streptococcus pneumoniae were identified in 8% (5 cases) and 5% (3 cases) of cases respectively. Pseudomonas pseudomallei was identified in 4 cases (7%) with a 100% mortality. Overall, gram-negative organisms were identified in 47% of cases. APACHE II was significantly higher in non-survivors. Age, creatinine levels, and the presence of bacteraemia were not prognostic features. CONCLUSION: SCAP in Singapore carries a high mortality with the predominance of gram-negative organisms. Empiric antibiotics should include gram-positive and gram-negative coverage with specific coverage for Pseudomonas pseudomallei.

Adolescent↗
PubMed1996

Treatment of complicated parapneumonic effusions and pleural empyema: a four-year prospective study.

We studied prospectively the microbiologic findings, management, including the use of intrapleural streptokinase to improve pleural drainage, and outcome of 33 patients with complicated parapneumonic effusions (6) frank empyema (27) treated by our unit over a 4-year period. The mean age was 61 years, with more male (26) than female (7) patients. Seventy-nine percent of the patients had some form of underlying illness, especially chronic lung disease (46%), followed by diabetes mellitus (23%). Fifteen percent of the pleural collections were loculated. Pleural fluid cultures were positive in 58%, Staph aureus and Kleb pneumoniae being the most prevalent aerobic isolates. The incidence of anaerobic isolates was 32%. Besides empirical antibiotics, all patients had drainage of the pleural collections at diagnosis. Four patients were treated with needle aspiration; 28 (85%) required thoracostomy tube drainage for a mean of 8 days, 5 of these went on to surgical decortication. Thirteen patients received intrapleural streptokinase (SK) to facilitate drainage, with significant increase in the volume drained. The mean duration of stay for the whole group was 22 days. The administration of intrapleural SK did not significantly shorten the duration of hospital stay. There were six deaths (18%), none as a direct result of the empyema. We describe a therapeutic approach to parapneumonic effusions and empyema which tailors the interventional modality to the clinical stage of disease.

Adolescent↗
PubMed1995

Detection of Mycobacterium tuberculosis in sputum, pleural and bronchoalveolar lavage fluid using DNA amplification of the MPB 64 protein coding gene and IS6110 insertion element.

Two gene sequences specific for Mycobacterium tuberculosis were evaluated for the diagnosis of pulmonary tuberculous (PTB) in pleural fluid (PF), bronchoalveolar lavage fluid (BAL) and sputum (Sp). The 240 bp sequence (nts 460-700) coding for the MPB 64 protein coding gene and the 123 bp IS6110 insertion element present in multiple copies in the mycobacterial genome were amplified using the polymerase chain reaction. Fifty-nine clinical specimens were studied. The diagnosis of PTB was confirmed by positive M. tuberculosis cultures in 14 specimens, and by the presence of characteristic histological features of granuloma and Langerhan's giant cells on pleural biopsy in 3 PF specimens through cultures for M. tuberculosis were negative. The remaining 42 specimens were obtained from patient's with non-tuberculosis pulmonary infections or malignancy, and these served as negative controls. Our results showed that the IS6110 insertion element and MPB 64 gene sequence were detected in all 14 culture positive PTB cases, although detection of the latter sequence required both DNA amplification and oligonucleotide hybridization. There was however one false positive specimen with the MPB 64 detection protocol. More importantly, both the MPB 64 sequence and IS6110 insertion element protocols were unable to detect M. tuberculosis DNA in the 3 PF samples diagnosed by histological characteristics on pleural biopsy and culture negative. We conclude that DNA amplification for M. tuberculosis-specific sequences is a useful method for rapid diagnosis of PTB in culture positive specimens. However, the false negative results with TB culture negative cases of tuberculosis pleurisy, limits its usefulness for the diagnosis of tuberculous pleurisy.

Base Sequence↗
PubMed1994

Klebsiella bacteraemia: a report of 101 cases from National University Hospital, Singapore.

One hundred and one cases of Klebsiella bacteraemia from the National University Hospital, Singapore, were reviewed retrospectively. There were 54 (53.5%) males and 47 (46.5%) females. Mean (+/- SE) age was 54 (+/- 2.4) years. Overall mortality was 26%. Nosocomial infections accounted for 20%. Underlying diabetes mellitus and malignancy were present in 36 and 26% respectively. The source of the bacteraemia was not known in 33% of cases, 17% had liver abscess, 29% had urinary tract infections, 9% had pneumonia, 10% had an abscess separate from the liver, and 3% had biliary sepsis. Elevated alkaline phosphatase (> 100 U-1) was seen in all cases of liver abscess (sensitivity 100%, specificity 27%). Nonsurvivors had a significantly lower platelet count than survivors (104 +/- 25 x 10(9)/l vs. 176 +/- 15 x 10(9)/l, unpaired t-test P < 0.05), and a platelet count of less than 150 x 10(9)/l was associated with a significantly higher mortality (37% vs. 11%, chi 2 P < 0.01). Nosocomial infection was associated with 45% mortality, whereas community-acquired infection had a lower rate of 21%, this was not statistically significant. Seventy-eight per cent of these Klebsiella isolates were sensitive to gentamicin and cotrimoxazole, and 100% to imipenem.

Anti-Bacterial Agents↗
PubMed1994

Regulation of the immunostimulatory activity of rat pulmonary interstitial dendritic cells by cell-cell interactions and cytokines.

Pulmonary dendritic cells (DC) are potent antigen-presenting cells that are thought to play a critical role in the initiation of immune responses within the lung. Because the lung is both a site of entry into the body for microbial pathogens and the organ of gas exchange, pulmonary immune responses must be meticulously regulated to achieve a balance between host defense and respiration. The initial interaction of DC with T cells in the lung is an excellent point at which to control local immune responses. Studies of the regulation of DC accessory cell function have been greatly hampered by difficulties in obtaining pure populations of pulmonary DC that have not been subjected to prolonged incubations during which the DC may undergo functional alteration. We now describe a method for isolating pulmonary DC from the rat that yields 1 x 10(5) cells/rat with > 90% purity. These cells are potent accessory cells, inducing T cell proliferation in a mixed leukocyte reaction (MLR) at a stimulator-to-responder ratio of 1:1,000. This method, which involves flow cytometric separation of nonphagocytic cells that stain brightly for class II MHC (OX6) from a population of low-density pulmonary interstitial cells, avoids extended incubations at 37 degrees C and thus allows study of a relatively pure population of cells that have functional capacities resembling those of naive cells from the normal lung. With these cells, we demonstrate that the functional capacity of pulmonary DC as stimulator cells in an MLR is significantly increased by exposure to the cytokines interleukin-1 or granulocyte/macrophage colony-stimulating factor (GM-CSF) and by culture with interstitial, but not alveolar, macrophages. Furthermore, DC are heterogeneous with respect to the cell surface expression of receptor for GM-CSF, and this expression is subject to modulation in cell culture. From these studies, we conclude that the immunostimulatory capacity of pulmonary DC is a function of local interactions with cytokines and other parenchymal cells. This suggests that DC function may be an important regulatory point for the local control of pulmonary immune responses.

Animals↗
PubMed1994

Rapid shallow breathing (frequency-tidal volume ratio) did not predict extubation outcome.

This was a prospective study of 52 patients that were extubated in our medical intensive care unit. Rapid shallow breathing, represented by a ratio of frequency to tidal volume (f/VT) of more than 105, was evaluated either on continuous positive airway pressure or pressure support prior to extubation as a marker of extubation outcome. Twelve out of 13 patients (92 percent) with rapid shallow breathing (f/VT ratio > 105) were successfully extubated. Out of 9 extubation failures only 1 patient had a f/VT ratio more than 105 (11 percent). A measured f/VT ratio of less than 105 had a sensitivity and specificity of 72 and 11 percent, respectively, for extubation success. Patients who had unsuccessful outcomes were ventilated for a significantly more prolonged period (9.6 +/- 6.8 d vs 4.6 +/- 3.9 d, unpaired t test, p = 0.004). We conclude that the presence of rapid shallow breathing during a weaning trial with the patient on partial ventilatory support does not necessarily preclude successful extubation.

Adolescent↗
PubMed1994

Polymyositis associated with symptomless nasopharyngeal carcinoma.

We describe a 42-year-old Chinese patient with polymyositis and nasopharyngeal carcinoma. The polymyositis was complicated by respiratory failure needing mechanical ventilation despite conventional therapy. Treatment of the carcinoma was associated with recovery of muscle strength. To our knowledge this is the first reported association of polymyositis with nasopharyngeal carcinoma.

Adult↗
PubMed1993

Factors influencing pulse oximetry as compared to functional arterial saturation in multi-ethnic Singapore.

Noninvasive oximetry provides continuous monitoring of arterial oxygen saturation and hence, early detection of hypoxia. This has proved to be a useful adjunct to patients' safety, and is considered indispensable in certain settings. However, errors may be present in the pulse oximeter estimation (SpO2) of arterial oxygen saturation (SaO2), which may be due to various parameters. We have studied a multi-ethnic population where the skin pigmentation is different, and also under different conditions comparing SpO2 with SaO2. Our results showed that SpO2 estimation of SaO2 amongst the three racial groups (Chinese, Malays, and Indians) varied significantly (ANOVA, p < 0.05). The over-estimation was more pronounced by hypoxic conditions and jaundice. Haemoglobin and systolic blood pressure did not affect the difference between SpO2 and SaO2.

Adult↗
PubMed1993

Moraxella catarrhalis respiratory infection in adults.

Moraxella catarrhalis (MC) is an upper respiratory tract commensal which may also be pathogenic. In this report we examined the clinical features, microbiology and therapeutic response in 30 consecutive adult patients with pneumonia who had MC isolated in the sputum. The mean age was 66 years with an equal sex ratio. Most patients gave a history of cigarette smoking (77%) and had underlying pulmonary diseases (73%). Dyspnea and productive cough were the most common complaints (87%). Fever was a manifestation in 60% of patients. Chest X-ray features of pneumonia were noted in 78% of patients while leucocytosis (> 11,000/mm3) was evident in 70%. While all isolates were susceptible to tetracycline, 70% were resistant to penicillin/ampicillin by in-vitro testing. Three patients died, two from their underlying illnesses and one from myocardial infarct. We believe that MC isolated in sputum cultures from symptomatic adults with underlying respiratory diseases should be treated as a pathogen. The short term prognosis is good.

Adult↗
PubMed1993

Acute physiology and chronic health evaluation (APACHE II) scoring in the Medical Intensive Care Unit, National University Hospital, Singapore.

The intensive care unit provides multisystem support and therapy to critically ill patients, and represents an expensive part of hospital medicine. This survey validates the use of APACHE II as a severity scoring system that allows reliable prediction of outcome of intensive care patients in Singapore. The mortality rate of 37.4% in our medical intensive care unit compares favourably with the other established intensive care units in the United States of America. Our results also indicate that the aged fared as well as their younger counterparts. Patients with sepsis fared poorer than expected from their APACHE II scores, and stroke patients needing intensive care admission had an extremely poor prognosis (mortality rate of 85.7%). High APACHE II scores are associated with invasive haemodynamic monitoring.

Adolescent↗
PubMed1993

Respiratory failure from combined emphysema and pulmonary fibrosis.

An elderly man presented with hypoxemic respiratory failure and pulmonary hypertension. He was a heavy cigarette smoker and had been treated previously for pleuro-pulmonary tuberculosis. His lung volumes and airway function were normal. High resolution computer tomographic (HRCT) examination revealed combined upper lobe emphysema and lower lobe fibrosis. Routine pulmonary function tests may underestimate the degree of functional impairment in patients with combined emphysema and fibrosis. The HRCT examination however provided valuable information.

Aged↗
PubMed1992

Failure of inhaled corticosteroids to modify bronchoconstrictor or bronchodilator responsiveness in middle-aged smokers with mild airflow obstruction.

We have compared the effects of three-month periods of treatment with an inhaled corticosteroid, budesonide 600 micrograms twice daily and with placebo on bronchial responses to inhaled histamine and to bronchodilators in a double-blind crossover trial in 14 middle-aged male smokers (mean age, 59.6 years) with mild airways obstruction (mean FEV1 2.42 L, 80 percent predicted [range, 48 to 110 percent]). Responsiveness to inhaled histamine was assessed monthly by the provocative concentration (mg/ml) reducing FEV1 by 20 percent (PC20). Bronchodilator response to a combination of inhaled salbutamol (5 mg) and ipratropium (0.5 mg) was assessed before and after three months' treatment. Compliance with treatment was checked by weighing aerosol canisters, and by measuring plasma budesonide and metabolites. There was no significant change in FEV1 (budesonide mean 2.38 L [SEM 0.17] vs placebo 2.40 L [0.17]), vital capacity (budesonide mean 3.69 L [0.17] vs placebo 3.81 L [0.17]) or in bronchodilator responsiveness (mean increase over baseline FEV1, budesonide 11.6 [2.7] percent vs placebo 10.5 [3.2] percent). There was a small overall reduction in bronchoconstrictor responsiveness over the period of the trial, but there was no effect of 12 weeks of budesonide treatment compared with 12 weeks of placebo treatment (mean log PC20 during budesonide 0.595 [SEM 0.063], placebo 0.591 [SEM 0.055]). Following the three-month crossover trial, six men continued for nine more months to receive budesonide in a single-blind trial and the results were compared with those in six men who took no active treatment for the subsequent nine months. No improvements in baseline spirometry, home peak flow measurements, bronchoconstrictor or bronchodilator responsiveness were observed after 12 months of budesonide treatment. Thus, a regimen of budesonide treatment that consistently attenuates bronchial responsiveness in asthmatic subjects had no effect in these men; larger and longer trials will be required to establish whether a subgroup of smokers shows a favorable response.

Administration, Inhalation↗
PubMed1992

Nasal positive pressure ventilation in the treatment of chronic hypercapnic respiratory failure: a case report.

This paper describes the use of a nasal mask to deliver intermittent positive pressure ventilation to treat chronic respiratory failure in one patient with severe kyphoscoliosis. After two months of overnight nasal ventilation at home the patient achieved normal blood gases, showed improved inspiratory muscle strength, effort tolerance and was able to return to work. Intermittent nasal ventilation is a safe and effective ventilatory support modality for some patients with hypercapnic respiratory failure.

Adult↗