Huang Cc

Aminoguanidine reduces glomerular inducible nitric oxide synthase (iNOS) and transforming growth factor‐beta 1 (TGF‐β1) mRNA expression and diminishes glomerulosclerosis in NZB/W F1 mice

Over‐expression of iNOS is implicated in the pathogenesis of glomerulonephritis in animal models of systemic lupus erythematosus. The aim of this study was to evaluate the effect of aminoguanidine, a selective inhibitor of iNOS, for the protection from glomerulosclerosis in NZB/W F1 mice. Female NZB/W F1 mice (nu2003=u20038) were treated with aminoguanidine (1u2003g/l) in drinking water for 4 months starting at age 2 months before the onset of glomerulonephritis. Controls were age‐ and sex‐matched mice (nu2003=u200310) without aminoguanidine treatment. By glomerular microdissection and reverse‐transcription competitive polymerase chain reaction, we found that glomerular iNOS/β‐actin and TGF‐β1/β‐actin mRNA ratios were reduced 15.1% (Pu2003<u20030.05) and 61.3% (Pu2003<u20030.01), respectively, in aminoguanidine‐treated mice. Aminoguanidine significantly reduced the glomerular iNOS staining, urinary nitrite production and degree of glomerulosclerosis. In addition, the glomerular volume and mean glomerular cell number were reduced 33.2% (Pu2003<u20030.01) and 32.8% (Pu2003<u20030.01), respectively. Likewise, the urinary proteinuria was also significantly reduced by aminoguanidine. These results indicate that administration of aminoguanidine may reduce the progression of glomerulosclerosis in NZB/W F1 mice, possibly through inhibition of glomerular nitric oxide production.

Bilateral diaphragmatic paralysis--a rare cause of acute respiratory failure managed with nasal mask bilevel positive airway pressure (BiPAP) ventilation

A 68 yr old woman presented with acute respiratory failure. She was suspected of having a phrenic-diaphragmatic impairment, without evidence of an intrinsic lung disease or generalized neuromuscular disorder, after 3 weeks of prolonged mechanical ventilation. A series of studies, including fluoroscopy, phrenic nerve stimulation test and diaphragmatic electromyography, was performed before the diagnosis of bilateral diaphragmatic paralysis (BDP) was confirmed. The patient was successfully weaned from the conventional mechanical ventilator, and was placed on nasal mask bi-level positive airway pressure (BiPAP) ventilation. A high degree of clinical suspicion of bilateral diaphragmatic paralysis should always be raised in patients suffering respiratory failure without definite predisposing factors. Weaning with noninvasive nasal mask ventilation should be tried first instead of direct tracheostomy.

Oxygen, arterial blood gases and ventilation are unchanged during dialysis in patients receiving pressure support ventilation

This study was undertaken to observe whether dialysis-induced alveolar hypoventilation and arterial hypoxaemia occur during bicarbonate haemodialysis in patients receiving partial mechanical support with pressure support ventilation. Nineteen patients admitted to the medical intensive care unit requiring mechanical ventilation and haemodialysis were enrolled. Arterial blood gas, white blood cell (WBC) count, minute ventilation, respiratory rate, breathing pattern and blood pressure were measured according to the following time schedule: pre-dialysis (time 0), and at 15, 30, 60, 120, 180, 240 min thereafter. Results showed that, with the use of cuprammonium dialyser, the WBC count dropped immediately and reached the nadir 15 min after haemodialysis. Thereafter, it recovered and overshot the pre-dialysis values until the end of dialysis. The bicarbonate dialysate indeed resulted in rapid and significant metabolic alkalosis. However, no decrease of PaO2 occurred throughout haemodialysis. The tidal volume, minute ventilation and breathing pattern remained stable during haemodialysis. We conclude that neither dialysis-induced alveolar hypoventilation nor arterial hypoxaemia developed during bicarbonate dialysis in patients mechanically ventilated with the pressure support ventilation.

Spontaneous variability of arterial oxygenation in critically ill mechanically ventilated patients.

Objective: To assess the magnitude of spontaneous variability of arterial oxygenation and oxygen tension-based indices over time in medical intensive care unit (ICU) patients and to study whether high positive end-expiratory pressure (PEEP) or inverse inspiratory-to-expiratory (I:E) ratio ventilation (IRV) results in a greater variability than low PEEP with conventiona l I:E ratio ventilation. Design: Prospective study. Setting: Medical ICU in a tertiary medical center. Participants: 23 patients requiring a pulmonary artery floating catheter for hemodynamic monitoring. Intervention: After being completely sedated, patients were randomized to receive pressure-control ventilation at setting A: high PEEP (15 cmH2O) with conventional I:E ratio (1:2) and setting B: inverse I:E ratio (2:1) with low PEEP (5 cmH2O) alternately, and then at setting C: low PEEP (5 cmH2O) with conventional I:E ratio (1:2). Each ventilation setting lasted 1 h. Measurements and results: The arterial and mixed venous blood samples were measured simultaneously at baseline (time 0), and at 15, 30, 45, and 60 min thereafter. The coefficient of variation (CV) of arterial oxygen tension (PaO2) over time was 5.9 % for setting A, 7.2 % for setting B, and 6.9 % for setting C. ANOVA showed no significant differences in CVs of PaO2 between the three settings. Oxygen tension-based indices, alveolar-arterial oxygen difference (A-aDO2) and PaO2/PAO2 (alveolar oxygen tension), displayed CV s equal to that of PaO2; the CV of A-aDO2/PaO2 was significantly greater than that of PaO2. Conclusions: In critically ill medical ICU patients, despite sedation, the spontaneous variability in PaO2 over time is substantial. A high PEEP or IRV does not contribute to the increased variation in PaO2.

The Outcome of Terminal Cancer Patients Requiring Prolonged Mechanical Ventilation

Background: Approximately 76% of patients with malignancies die because of respiratory failure, excluding pneumonia and pulmonary embolisms, in intensive care centers (ICU). Currently, no published paper has described the outcome of adult cancer patients who require prolonged mechanical ventilation (PMV) (more than 21 days) for respiratory failure. The objective of this study was to describe the outcome of terminal cancer patients requiring PMV. Methods: A retrospective study of 1124 patients who were admitted to our respiratory care center (RCC) from November 1999 to August 2004 was carried out. All terminal cancer patients with respiratory failure requiring prolonged mechanical ventilation were included in the study group. Demographic and clinical variables, such as age, gender, APACHE score at RCC admission, biochemistries, Glascow coma scale, ICU admission day, cancer types, and blood gas result, were obtained from consecutive respiratory failure patients. Information regarding vital status after hospital discharge was also acquired. Results: Our analysis was based on data from 92 adult terminal cancer patients who met the criteria. Twenty-three patients were transferred out of the RCC, including 15 successfully weaned patients and 8 ventilator-dependent patients. In the successfully weaned group, 8 patients expired within 3 months, and the other 7 were discharged from the hospital, but all of them died within 4 months. In the ventilator-dependent group, 1 patient died in the hospital, and 7 were transferred to a local respiratory care ward (RCW). After being admitted to the RCW, 5 of 7 patients expired within 2 months, and only 2 survived more than 2 months. The overall observed in-hospital mortality was 84%, and mean survival time after discharge from the RCC was 70 days. The APACHE Ⅱ score (p=0.001) and serum BUN (p=0.0049) were significantly lower in the successfully weaned group, and the Glascow coma scale was higher in this group (p=0.004). In our analysis, age, gender, cancer type, and ICU admission days were not significant factors influencing the outcome. Conclusion: The overall in-hospital mortality of terminal cancer patients requiring PMV was as high as 84%, and mean survival times after discharge from the RCC were only 70 days. The patients with a lower BUN level and severity of disease had a higher ventilator weaning rate. This result may be of help to physicians and families when discussing whether aggressive or hospice care is more suitable for terminal cancer patients with respiratory failure.

Patient with Small Cell Lung Carcinoma-Induced Acute Pancreatitis: A Case Report

Pancreatic metastases are found in up to 40% of patients with disseminated malignancy. Metastases-induced acute pancreatitis is a rare condition in 3-7% of these patients, and has a poor prognosis. Differentiating metastases-induced acute pancreatitis from the usual forms of acute pancreatitis is almost impossible using noninvasive methods, though the lack of response to conventional management provides a clue. Chemotherapy may provide a survival benefit in some patients, and should be considered on an individual basis. Herein, we describe the case of a 69-year-old man with recurrent small cell lung cancer, which induced acute pancreatitis. This patient initially received conservative treatment without significant clinical improvement. Chemotherapy then was attempted, and the patient survived for over 4 weeks after this treatment, showing a clinical improvement of the pancreatitis