The effect of lateral position on oxygenation in ARDS patients: a pilot study.

BACKGROUND: The effect of body position on oxygenation in acute respiratory distress syndrome (ARDS) patients has long been known. Prone position improves the PaO2 in 60-70% of ARDS patients. However the effect of the lateral positions, which are used in routine critical care, has never been reported. OBJECTIVE: To determine whether placing the patient in a lateral position has any effect on oxygenation in ARDS. MATERIAL AND METHOD: Prospective observational study, comparing oxygenation in ARDS patients between supine, right and left lateral positions (> or = 60 degree). RESULTS: We included 18 ARDS patients, their mean aged was 52.2 +/- 19.6 years, 14 were men and the ICU mortality rate was 61.1%. There was no significant change in the mean PaO2, arterial blood gas parameters, respiratory mechanics and hemodynamic parameters between the supine and decubitus positions in the overall group. However there was a trend toward increasing the mean PaO2 during right lateral position compared with the supine position (90.3 +/- 29.0 vs 84.6 +/- 20.4, p = 0.23). Nine patients who responded to the right lateral position had significantly higher mean PaO2 during the right lateral position than in the supine position (107.8 +/- 29.0 vs 85.6 +/- 21.8, p < 0.0001). In this group, four patients had predominant left pulmonary infiltration and five patients had equally bilateral pulmonary infiltration on chest X-ray. Unfortunately, the PaO2 in three patients decreased more than 10 mmHg during right lateral decubitus. CONCLUSION: The PaO2 increased while in the right lateral position in patients with predominant left pulmonary infiltration or bilateral infiltration. This effect may be due to the small sample size. A further large-sized randomized controlled study is needed.

Thrombocytopenic purpura associated with miliary tuberculosis.

The authors report a case of thrombocytopenia associated with miliary tuberculosis. The patient was a 28-year-old woman who was admitted because of massive upper gastrointestinal hemorrhage and acute respiratory failure. Chest radiographs revealed diffuse bilateral reticulonodular infiltration and complete blood count was significant for severe thrombocytopenia. Bone marrow biopsy was performed to investigate the cause of thrombocytopenia and demonstrated multiple tiny caseating granulomas suggesting miliary tuberculosis (TB). She received anti-TB therapy and a short course of steroid with good response. Platelet count returned to normal limit within 10 days. Although isolated thrombocytopenia is uncommon in TB, it is still important to consider TB in the differential diagnosis of thrombocytopenia, particularly in patients with abnormal chest radiographs. Bone marrow examination is very helpful in this situation.

Invasive streptococcal group A infection and toxic shock syndrome in Songklanagarind hospital.

BACKGROUND AND OBJECTIVES: Streptococcal group A infection is reported as a medical problem in several parts of the world. The most serious complication of this infection is streptococcal toxic shock syndrome (STSS) which is associated with a very high mortality rate. The present study aimed to determine the clinical manifestations, including underlying conditions, mortality and prognostic factors, of invasive streptococcal group A infection and STSS from southern Thailand (Songklanagarind Hospital). METHOD: The medical records of infected patients from January 1, 1995 to June 30, 1999 were reviewed retrospectively. Criteria for diagnosis of STSS were as follows (JAMA 1993). Prognostic factors were analyzed by logistic regression model. RESULT: 176 cases of STSS and streptococcal group A infection, 89.9 per cent were community acquired infections. About 70 per cent of the infected patients had previous underlying conditions, the most common was cancer. The commonest site of infection was the skin and soft tissue (80.1%). The total mortality rate from streptococcal group A infection was 9.1 per cent. STSS was identified in 12 patients (6.8%), with a 50 per cent mortality rate. Prognostic factors for mortality in this infection were diabetic mellitus (odds ratio 9.67, p<0.025), history of steroid use (odds ratio 11.17, p<0.017), STSS (odds ratio 22.16, p<0.005) and received cancer chemotherapy (odds ratio 115.19, p<0.003). Predictive factors for STSS couldn't be identified, while age >65 years and steroid use were suggested protective factors for this condition [odds ratio 0.02, p<0.0001 and odd ratio 0.07, p<0.027 respectively].