Association of Sauropus androgynus and bronchiolitis obliterans syndrome: a hospital-based case-control study.

In late April 1995, an outbreak of a poorly defined respiratory illness related to the ingestion of leaves of Sauropus androgynus was observed in southern Taiwan. To further evaluate the association between S. androgynus and bronchiolitis obliterans syndrome, a hospital-based case-control study was conducted with one case group and three different control groups at Veterans General Hospital-Kaohsiung between April and September 1995. A total of 54 cases (50 females, 4 males), 54 age- and sex-matched neighborhood controls, 54 matched routine physical check-up controls, and 54 matched self-referred patron controls (who had ingested S. androgynus yet without obstructive physiology) were interviewed for clinical symptoms, history of S. androgynus consumption, and potential confounding factors. All 54 cases (100%) ingested S. androgynus compared with only five (9%) neighborhood controls (matched odds ratio (OR) incalculable, p < 0.001) and two (4%) physical check-up controls (matched OR incalculable, p < 0.001). In the univariate analysis of 54 cases and 54 self-referred patron controls, factors associated with an increased risk of bronchiolitis obliterans syndrome were methods of food preparation (uncooked juice vs. stir fried or boiled dishes, matched OR 10.3 (95% confidence interval (CI) 1.3-84.4)); preparer of the S. androgynus-containing food (vendor only vs. patient only or patient plus vendor, matched OR 2.8 (95% CI 1.1-7.1)); total S. androgynus consumption quantity (> 4,500 vs. 413-2,063 g, matched OR 10.0 (95% CI 1.9-53.0)); duration of consumption (> 45 vs. 6-24 days, matched OR 2.1 (95% CI 1.2-3.8)); and midterm interruption (< 2 vs. 2-5 days per week, matched OR 2.6 (95% CI 1.1-6.1)). Additionally, multiple conditional logistic regression analysis of cases and self-referred patron controls revealed that a larger total amount of S. androgynus consumption, preparation of S. androgynus food without cooking, and ingesting S. androgynus food prepared by a vendor were the significant risk factors associated with bronchiolitis obliterans syndrome.

Correlation of high-resolution CT and pulmonary function in bronchiolitis obliterans: a study based on 24 patients associated with consumption of Sauropus androgynus.

OBJECTIVE: An outbreak of Sauropus androgynus-associated bronchiolitis obliterans occurred in Taiwan in the summer of 1995. We undertook a study of the correlation between high-resolution CT findings and pulmonary function testing in patients from this outbreak. MATERIALS AND METHODS: We evaluated inspiratory-expiratory high-resolution CT scans of 24 patients with S. androgynus-associated bronchiolitis obliterans. The presence of bronchiectasis was assessed by two visual scores (a bronchial dilatation score and a bronchiectasis extent score). Extent of air-trapping was assessed visually and given a score. We also used computer software to assess the extent of air-trapping and generate scores of dynamic attenuation. Spirometry, plethysmography, and diffusion capacity of each patient were also obtained. RESULTS: All four scores had statistically significant correlation with forced expiratory volume in 1 sec (FEV1) (p < .05 for both bronchiectasis scores; p < .001 for both air-trapping scores). The two air-trapping scores had statistically significant correlation with forced vital capacity and diffusion capacity. We found the scores for dynamic attenuation had the greatest correlation with FEV1 (r = .85). We also found that mosaic attenuation was notable on expiratory CT scans alone in nine patients (type 1 air-trapping) and on both inspiratory and expiratory CT scans in 15 patients (type 2 air-trapping). In the latter group, FEV1 was significantly lower (p < .01). CONCLUSION: Findings from high-resolution CT of air-trapping were more important than findings of bronchiectasis when correlating pulmonary function with S. androgynus-associated bronchiolitis obliterans. Type 2 air-trapping suggested a more severe air-flow obstruction than did type 1. Scores for quantitative attenuation generated by computer software were helpful in assessing air-trapping and correlating it with pulmonary function. These findings may apply to patients with bronchiolitis obliterans from other causes.

The outcome of terminal liver cirrhosis patients requiring mechanical ventilation.

BACKGROUND: Liver cirrhosis is a common problem in Taiwan. Without liver transplantation, patients with end-stage liver cirrhosis frequently die of various complications and often require mechanical ventilatory support prior to their death. The purpose of this study was to investigate the in-hospital and short-term outcome of such patients. METHODS: A retrospective review of 47 medical records of mechanically ventilated patients with primary diagnosis of liver cirrhosis, admitted from November 1990 to September 1993, allowed analysis of disease course and outcome for these patients. RESULTS: Among the 47 patients, a Child-Pugh's class A patient receiving temporary mechanical ventilation (MV) after elective devascularization surgery was excluded from analysis. Among the remaining medically treated 46 patients, there were 33 Child-Pugh's class C patients, 9 class B patients and 4 unclassified patients. Primary reasons for endotracheal intubation and MV included airway protection, acute respiratory distress and shock. Of these patients, shock was present in 39 cases, upper gastrointestinal bleeding in 34, systemic inflammatory response syndrome in 32, renal insufficiency with creatinine greater than 1.3 mg/dl in 32, bacteremia in 14, parenchymal lung disease in 16, spontaneous bacterial peritonitis in 10, and intracerebral hemorrhage in 1 during their hospital courses. Thirty-eight patients (83%) died within 72 hours after being placed on mechanical ventilation. Patients requiring MV with complications of bacteremia, parenchymal lung disease or renal insufficiency during hospitalization were found to have a 100% mortality rate. Successful weaning occurred in only 3 of 46 patients (8.7%). Of these three, two (4.3%) went home alive and had survived over six months after discharge. CONCLUSIONS: It was concluded that cirrhotic patients requiring MV have an extremely poor prognosis. Patients and their families should be fully informed of the prognosis, and routine use of MV should not be encouraged in patients with terminal stage liver disease.

Effectiveness of a continuous quality improvement program aiming to reduce unplanned extubation: a prospective study.

OBJECTIVE: To evaluate the effectiveness of a continuous quality improvement (CQI) program in reducing the incidence of unplanned endotracheal extubation. DESIGN: Prospective study over a 9-month period. SETTING: Adult intensive care units (ICUs including coronary care unit, medical ICU, surgical ICU, and cardiovascular surgical ICU) in a university-affiliated medical center. PATIENTS: 831 consecutive mechanically ventilated patients. INTERVENTIONS: CQI program focusing on standardization of procedures, improvement of communication, and identification and management of high-risk patients. MEASUREMENTS AND RESULTS: With the implementation of this CQI program, the overall incidence density of unplanned extubation (defined as number of new unplanned extubations per mechanical ventilation patient-days) significantly decreased from 2.6% in the first trimester to 1.5% in the second trimester and 1.2% in the third trimester (p = 0.01). This reduction was essentially the result of a decrease in unplanned extubation in orally intubated patients (incidence density 4.6, 1.7 and 1.0% for three trimesters, respectively; p < 0.0001). Unplanned extubation in nasally intubated patients remained largely unaffected (1.2, 1.4, and 1.4% for three trimesters, respectively; p = 0.92). CONCLUSIONS: The implementation of a concerted CQI program is effective in reducing the overall incidence of unplanned endotracheal extubation.

Outbreak of bronchiolitis obliterans associated with consumption of Sauropus androgynus in Taiwan.

BACKGROUND: In August, 1995, there was an outbreak in Taiwan of rapidly progressive respiratory distress associated with consumption of uncooked Sauropus androgynus, a vegetable with a claimed yet unconfirmed effect on weight control. We report on 23 patients with strikingly similar clinical presentations. METHODS: A structured questionnaire for clinical manifestations was completed. Radiographic findings, pulmonary physiological changes, immunological and microbiological studies, and pathological examination were evaluated. FINDINGS: All patients were young and middle-aged women (mean age 39 years [range 21-52]). They took uncooked S androgynus juice, generally mixed with guava or pineapple juice, for a mean duration of 10 weeks. Progressive dyspnoea and persistent cough were the main symptoms on presentation. Pulmonary function testing uniformly revealed moderate to severe airflow obstruction with mean forced expiratory volume in 1 s (FEV1) of 0.66 L (26% of predicted). No bronchodilator response was observed. Room-air arterial blood gas analysis showed hypoxaemia (mean PaO2 9.6 [SD 1.6] kPa). Chest radiographs were essentially normal. High-resolution computed tomography showed bilateral bronchiectasis and patchy low attenuation of lung parenchyma with mosaic perfusion. Ventilation-perfusion scintigraphic findings were compatible with obstructive lung disease. Histopathology of open lung biopsy specimens in four patients confirmed the presence of bronchiolitis obliterans. Immunohistochemical stains of the open lung biopsy specimens showed predominance of T cells over B cells. Immunofluorescent stains for IgG, IgM, IgA, C1q, C3, and C4 were negative. Serum concentrations of tumour necrosis factor alpha were higher than those of normal controls. Clinical response to prednisolone was limited. INTERPRETATION: We describe an unusual association between bronchiolitis obliterans and ingestion of the vegetable S androgynus. T-cell mediated immunity may be involved in the pathogenesis.

[Outcome and cost of mechanical ventilation in patients with inoperable solid tumors and hematologic malignancies].

The application of mechanical ventilation can be life-saving in patients with acute respiratory failure, but is frequently ineffective in terminally ill patients. To analyze the outcome and cost of mechanical ventilation for patients with malignancies, we retrospectively reviewed 115 patients with inoperable solid tumors or hematologic malignancies who received mechanical ventilation. Eighty eight of these 115 patients (77%) died while on mechanical ventilation; 18 patients (16%) were weaned from mechanical ventilation but still died during their hospitalization. Six patients (5%) were discharged but survived less than 3 months and only three patients (3%) survived for more than 3 months after discharge. The total time of mechanical ventilation was 772 person-days, which represented 5.5% (772/13974) of the total mechanical ventilator use in our hospital in 1993. The total hospital cost from initiation of mechanical ventilation to discharge or death of these 115 patients was NT $11,238,022 (US $432,200) and daily hospital cost per person during mechanical ventilation was approximately NT $10,845 (US $420). The "daily cost of discharge survival" (defined as total hospitalization cost from the initiation of mechanical ventilation to discharge or death divided by total discharge person-days) for patients with inoperable solid tumors was NT $73,421 (US $2,820)/per person-day. We concluded that mechanical ventilation should not be routinely used in patients with inoperable solid tumors and hematologic malignancies. Physicians should explain the poor outcome to these patients and their families in advance and inquire about their willingness to forego mechanical ventilation.

Use of noninvasive positive pressure ventilation via nasal mask in patients with respiratory distress after extubation.

BACKGROUND: Noninvasive positive pressure ventilation (NIPPV) has been successfully applied to provide ventilatory support in patients with chronic respiratory insufficiency as well as in selected patients with acute respiratory failure of various etiologies. To investigate the effectiveness of NIPPV via nasal mask in patients who develop respiratory distress after extubation, we prospectively studied 19 such patients (14 elective extubations and 5 self-extubations) who required no immediate reintubation. METHODS: The BiPAP ventilatory support system (BiPAP S/T-D, Respironics Inc., Murrysville, PA) via nasal mask was used to provide NIPPV in each patient. Inspiratory pressure support was adjusted to achieve comfort as well as adequate oxygenation and ventilation. RESULTS: Eleven patients were successfully transferred to regular oxygen supplement after an average trial of 38 hours. Persistent oral air leak despite the application of chin strap was observed in four of the eight failure cases and appeared to be the leading cause of NIPPV failure. When these patients were excluded, a success rate of 73% was achieved. Other factors contributing to failure included persistent hypoxemia, inadequate ventilation, worsening of underlying diseases and bronchial secretions. No major complication related to the use of NIPPV was observed. In the success group, respiratory rate significantly decreased by an average of 10 breaths/min at one hour after the commencement of NIPPV (p < 0.01). No significant changes of heart rate, blood pressure, Paco2 and pH were noted in either group. CONCLUSIONS: NIPPV via nasal mask may be considered as an alternative to endotracheal reintubation in selected extubated patients with respiratory distress who require no immediate reintubation.

Demand-flow airway pressure release ventilation as a partial ventilatory support mode: comparison with synchronized intermittent mandatory ventilation and pressure support ventilation.

OBJECTIVE: To evaluate airway pressure release ventilation as a partial ventilatory support mode by comparing a demand-flow airway pressure release ventilation system with synchronized intermittent mandatory ventilation and pressure support ventilation. DESIGN: Prospective, nonrandomized, cross-over trial. SETTING: Medical intensive care unit in a university medical center. PATIENTS: Sixteen consecutive patients without chronic obstructive pulmonary disease with mechanical ventilatory support of 25% to 75% of total minute ventilation on synchronized intermittent mandatory ventilation, or 25% to 75% of maximal pressure support level on pressure support ventilation. INTERVENTIONS: Each mode of mechanical ventilation was supplied to patients with comparable levels of partial support for 30 mins. MEASUREMENTS AND MAIN RESULTS: Among three different modes, demand-flow airway pressure release ventilation achieved the lowest peak airway pressure (airway pressure release ventilation 9.1 +/- 2.6 cm H2O; pressure support ventilation 18.4 +/- 4.6 cm H2O; synchronized intermittent mandatory ventilation 34.8 +/- 7.7 cm H2O; p < .001). Hemodynamic status and oxygenation status were similar among these three modes. Five (31%) of the 16 patients felt that demand-flow airway pressure release ventilation was a less comfortable mode than synchronized intermittent mandatory ventilation or pressure support ventilation. This finding had no clear correlation with their duration of airway pressure release, preset machine deflation rate, or inspiratory/expiratory ratio of machine breath. Gross asynchrony of effort and ventilator cycling was noticed in two (13%) patients while they were receiving demand-flow airway pressure release ventilation. CONCLUSIONS: We conclude that for patients who do not have chronic obstructive pulmonary disease, demand-flow airway pressure release ventilation can provide effective partial ventilatory support with lower peak airway pressure when compared with pressure support ventilation and synchronized intermittent mandatory ventilation. However, this airway pressure release ventilation system may be less comfortable than the other two modes, and asynchrony may occur in some patients.

Use of quantitative CT to predict postoperative lung function in patients with lung cancer.

PURPOSE: To evaluate the effectiveness of quantitative computed tomography (CT) for predicting postoperative lung function in patients with lung cancer. MATERIALS AND METHODS: Preoperative spirometry and conventional CT of the chest were performed in 38 patients. A postprocessing CT program was applied to quantitate the volume of whole-lung parenchyma with attenuations of -500 to -910 HU; this was defined as total functional lung volume (TFLV). The regional functional lung volume (RFLV) of the lobes or lung to be resected was quantitated separately. CT-predicted postoperative forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were derived by multiplying the preoperative spirometry values by (1 - RFLV/TFLV). RESULTS: CT-predicted values correlated well with postoperatively measured results (FEV1: r = .93, P < .001; FVC: r = .86, P < .001) in patients who underwent pneumonectomy or lobectomy, regardless of the patient's preoperative ventilation status. CONCLUSION: This method is effective in the prediction of postoperative FEV1 and FVC in patients undergoing pulmonary resection.