Evaluation of initial base deficit as a prognosticator of outcome in the pediatric trauma population.

Although the utility of the base deficit as an indicator of hypoperfusion and physiologic derangement in adults is well established, its value in the assessment of children is not as clear. The purpose of this study was to evaluate this tool with regard to injury severity, infectious morbidity, and outcome in a pediatric trauma population. A retrospective review of a 6-year period of the database of our level 1 pediatric trauma center was performed. One hundred seventeen severely injured children requiring mechanical ventilation were identified. Initial base deficit, Injury Severity Score, time to correction of this abnormality, ventilator days, infectious morbidity, and mortality were obtained and compared. Of the 117 patients included in this study, 30 patients were identified with an initial BD of less than or equal to -8 mEq/L and were placed into group 1. Group 2 consisted of the remaining 87 patients who presented with a base deficit (BD) of greater than -8 mEq/L. An admission base deficit of -8 mEq/L or less corresponded to a probability of mortality of 23 per cent as opposed to only 6 per cent with a BD greater than -8. Patients in group 1 remained on mechanical ventilation 9.4 +/- 8.1 days, whereas patients in group 2 remained ventilated 6.5 +/- 6.4 days; an increase of nearly 145 per cent. Likewise, the number of infectious complications rose 26 per cent with a worsening initial base deficit from 17 per cent of group 2 patients to 43 per cent of group 1 patients. We conclude that a high initial base deficit in injured children predicts a higher incidence of infectious complications and a less favorable outcome. This readily available laboratory study can identify those children most at risk of potentially preventable complications.

Arginase I expression and activity in human mononuclear cells after injury.

OBJECTIVE: To determine the effect of trauma on arginase, an arginine-metabolizing enzyme, in cells of the immune system in humans. SUMMARY BACKGROUND DATA: Arginase, classically considered an enzyme exclusive to the liver, is now known to exist in cells of the immune system. Arginase expression is induced in these cells by cytokines interleukin (IL) 4, IL-10, and transforming growth factor beta, corresponding to a T-helper 2 cytokine profile. In contrast, nitric oxide synthase expression is induced by IL-1, tumor necrosis factor, and gamma interferon, a T-helper 1 cytokine profile. Trauma is associated with a decrease in the production of nitric oxide metabolites and a state of immunosuppression characterized by an increase in the production of IL-4, IL-10, and transforming growth factor beta. This study tests the hypothesis that trauma increases arginase activity and expression in cells of the immune system. METHODS: Seventeen severely traumatized patients were prospectively followed up in the intensive care unit for 7 days. Twenty volunteers served as controls. Peripheral mononuclear cells were isolated and assayed for arginase activity and expression, and plasma was collected for evaluation of levels of arginine, citrulline, ornithine, nitrogen oxides, and IL-10. RESULTS: Markedly increased mononuclear cell arginase activity was observed early after trauma and persisted throughout the intensive care unit stay. Increased arginase activity corresponded with increased arginase I expression. Increased arginase activity coincided with decreased plasma arginine concentration. Plasma arginine and citrulline levels were decreased throughout the study period. Ornithine levels decreased early after injury but recovered by postinjury day 3. Increased arginase activity correlated with the severity of trauma, early alterations in lactate level, and increased levels of circulating IL-10. Increased arginase activity was associated with an increase in length of stay. Plasma nitric oxide metabolites were decreased during this same period. CONCLUSIONS: Markedly altered arginase expression and activity in cells of the human immune system after trauma have not been reported previously. Increased mononuclear cell arginase may partially explain the benefit of arginine supplementation for trauma patients. Arginase, rather than nitric oxide synthase, appears to be the dominant route for arginine metabolism in immune cells after trauma.

A single-center 8-year experience with percutaneous dilational tracheostomy.

OBJECTIVE: To determine surgical, postoperative, and postdischarge complications associated with percutaneous dilational tracheostomy (PDT) in an 8-year experience at the University of Kentucky. SUMMARY BACKGROUND DATA: There are known risks associated with the transport of critically ill patients to the operating room for elective tracheostomy, and less-than-optimal conditions may interfere with open bedside tracheostomy. PDT has been introduced as an alternative to open tracheostomy. Despite information supporting its safety and utility, the technique has been criticized because advocates had not provided sufficient information regarding complications. METHODS: A prospective database was initiated on all patients who underwent PDT between September 1990 and May 1998. The database provided indication, procedure time, duration of intubation before PDT, and intraoperative and postoperative complications. Retrospective review of medical records and phone interviews provided long-term follow-up information. RESULTS: In the 8-year period, 827 PDTs were performed in 824 patients. Two patients were excluded because PDT could not be completed for technical reasons. There were 519 male and 305 female patients. Mean age was 56 years. Prolonged mechanical ventilatory support was the most common indication. Mean procedure time was 15 minutes, and the average duration of intubation before PDT was 10 days. The intraoperative complication rate was 6%, with premature extubation the most common complication. The procedure-related death rate was 0.6%. Postoperative complications were found in 5%, with bleeding the most common. With a mean follow-up of greater than 1 year, the tracheal stenosis rate was 1.6%. CONCLUSIONS: On the basis of this large, single-center study, the authors conclude that when performed by experienced surgeons, PDT is a safe and effective alternative to open surgical tracheostomy for intubated patients who require elective tracheostomy.

Needle-localized biopsy of the breast.

Our experience with needle-localized biopsy for effective early detection and evaluation of carcinoma of the breast is discussed. Between January 1984 and December 1987, 266 women underwent 279 needle-localized biopsies of the breast performed at a large community teaching hospital. The majority of the women (221 of 266) were found to have benign disease of the breast and 162 of 221 of these were considered to have no increased risk of future carcinoma of the breast as determined by pathologic criteria. Thirty-eight women had primary malignant conditions. Seven patients had recurrent carcinomas after initial treatment with segmental mastectomy. The majority of both the primary and recurrent malignant lesions were infiltrating carcinoma. Using the Fischer exact test, a significant correlation (p less than 0.0004) was found between primary infiltrating carcinoma and a soft tissue mass on mammography. A significant correlation (p less than 0.03) was also found between primary intraductal carcinoma and clustered microcalcifications on mammography. Needle-localized biopsy of the breast provides early detection of carcinoma of the breast and identification of those at risk for subsequent carcinoma of the breast.