Clinical and laboratory findings in patients with pulmonary embolism in Phramongkutklao Hospital.

Pulmonary embolism (PE) was believed to be a rare disease and often misdiagnosed in Thailand. Only a few cases of PE in Thai patients have been reported. The purpose of this study was to describe the characteristics of history, physical examination and laboratory investigations in Thai patients with PE. Forty-nine patients diagnosed as PE in Phramongkutklao Hospital between 1994 and 1998 were included in the study. All patients underwent complete history, physical examination and appropriate laboratory studies. The mean age of this patient group was 53 years. Thirty-four per cent of these patients were first suspected of lung embolism while the others were misdiagnosed as congestive heart failure, myocardial infarction, pneumonia or septic shock. The most common syndrome was isolated dyspnea. Interestingly, chronic thromboembolic pulmonary hypertension which is uncommonly found in western countries was diagnosed in 12 per cent of our patients. Dyspnea, pleuritic pain, leg swelling, cough, tachypnea, tachycardia and increased pulmonary component of second heart sound were common symptoms and signs. A high-probability ventilation/perfusion lung scan and deep vein thrombosis were demonstrated in 93 per cent and 55 per cent of our patients, respectively. The mortality rate was 10 per cent.

Transbronchial needle aspiration in the diagnosis of bronchogenic carcinoma.

Transbronchial needle aspiration (TBNA) via a fiberoptic bronchoscope has been used for diagnosis of lung cancer by Wang since 1981. The technique uses a fiberoptic bronchoscope with a flexible needle that can penetrate the wall of the trachea and major bronchi. It is still underutilized and markedly depends on the physician's skill. We present our experience of TBNA for diagnosis of bronchogenic carcinoma. TBNA was performed on 47 consecutive patients with suspected lung cancer at the time of diagnosis bronchoscopy. Thirty six patients were diagnosed with bronchogenic carcinoma. TBNA demonstrated bronchogenic carcinoma in 61.1 per cent of the cases (22 of 36) and TBNA alone confirmed a malignant diagnosis in 33.3 per cent (12 of 36). The overall diagnostic yield of bronchoscope utilizing the conventional techniques of bronchial washing, brushings and biopsy was 50 per cent. With the addition of TBNA, bronchoscopy was diagnostic in 83.3 per cent of the patients. There were no serious complications. We concluded that TBNA is a safe technique that can significantly increase the diagnostic yield of conventional fiberoptic bronchoscopy in the diagnosis of bronchogenic carcinoma.

Efficacy of twice-daily amoxycillin/clavulanate in lower respiratory tract infections.

In this double-blind, double-dummy study, 324 patients with clinical evidence of community-acquired pneumonia (CAP) or an acute exacerbation of chronic bronchitis were randomly assigned to receive 10 days' treatment with either amoxycillin/clavulanate 875/125 mg twice daily or amoxycillin/clavulanate 500/125 mg three times daily. At the end of therapy, clinical success rates were 92.4% for the twice daily regimen and 94.2% for the three times daily regimen. There was no statistically significant difference between treatments (p = 0.647) and the 95% confidence interval around the treatment difference indicated that the two treatments were equivalent. Treatment equivalence was also confirmed at follow-up, four weeks after the end of treatment. Both regimens were well tolerated. In conclusion, amoxycillin/clavulanate 875/125 mg twice daily is as effective as amoxycillin/clavulanate 500/125 mg three times daily for the treatment of community-acquired lower respiratory tract infections and could improve patient compliance.

Proportional assist ventilation in acute respiratory failure: effects on breathing pattern and inspiratory effort.

Proportional assist ventilation (PAV) is a new mode of assisted ventilation which, by applying pressure in proportion to volume (volume assist, VA) and flow (flow assist, FA), should specifically reduce the inspiratory effort needed to overcome respiratory system elastance (Ers) and resistance (Rrs), respectively. The aims of this study were to determine (1) the effects of varying the level of VA on breathing pattern, inspiratory effort, and work of breathing, and (2) the interaction between VA and FA. In eight intubated patients with acute respiratory failure, four levels of VA (20 to 80% Ers) with and without a fixed amount of FA (approximately 50% Rrs) were evaluated. Compared with spontaneous breathing, VA increased tidal volume (VT) while respiratory rate (RR) was unchanged or fell slightly. The increase in minute ventilation (VE) was small and not significant. The addition of FA further increased VT while RR was significantly reduced so that VE remained unchanged. Increasing VA produced a graded reduction in inspiratory effort, reflected by decreases in the pressure-time integral of the diaphragm and the inspiratory muscles. These were further reduced when FA was added. VA decreased the elastic work of breathing (Wel) whereas resistive work (Wres) tended to increase so that the fall in total work (W/tot) was less than expected. At each VA setting, the addition of FA significantly reduced Wres and, as a result, Wtot. These results demonstrate that PAV can improve breathing pattern while reducing inspiratory effort by specifically decreasing Wel and Wres, and that VA and FA should be used together to optimize reductions in Wtot and the efficacy of assistance provided.