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Biomedical subjects

Betty J Tsuei

Publications and source records attributed to Betty J Tsuei.

10 recordsLinked to original sources
PubMed2005

Assessment of the pregnant trauma patient.

Although less than 10% of pregnant patients are likely to experience some type of physical trauma, injury is the leading non-obstetric cause of maternal mortality. The assessment and resuscitation of the injured pregnant patient must take into account the specific needs of both the mother and the foetus. This paper will review the physiology of pregnancy, discuss recent changes in assessment and resuscitation, and identify special injuries and issues specific to the pregnant trauma patient.

Cesarean Section↗
PubMed2005

Supplemental enteral arginine is metabolized to ornithine in injured patients.

BACKGROUND: Arginine has been added to immune enhancing diets that may improve patient outcomes, but little is known about the metabolic fate of supplemental arginine. We hypothesize that supplemental enteral arginine in injured patients is metabolized to ornithine by increased activity of the enzyme arginase. MATERIALS AND METHODS: Twenty-five adult patients with injury severity scores > or =20 received up to 14 days of enteral nutrition supplemented with arginine (30 g/day) or placebo in a prospective, randomized, blinded study. Plasma arginine, citrulline, and ornithine concentrations and peripheral blood mononuclear cell (PBMC) arginase activity were measured at baseline and on days 1, 3, 5, 7, 10, and 14. Clinical data collected included demographics, injury patterns, lengths of stay, and infectious complications. Data were analyzed using ANOVA and t test. RESULTS: PBMC arginase activity was elevated in all patients. In the supplemented group, plasma arginine concentrations increased at days 7, 10, and 14 when compared to baseline (P < 0.05) and were higher at day 14 when compared to those of controls (P < 0.05). Citrulline concentrations in both groups were unchanged over time. Ornithine concentration increased within 24 h of arginine supplementation and remained elevated when compared to baseline (P < 0.01). Ornithine concentration in the supplemented group was higher at days 1, 3, 5, and 7 when compared to that of controls (P < 0.05). There were no differences in clinical outcomes. CONCLUSIONS: Supplemental enteral arginine is absorbed in injured patients and increases arginine levels. Supplemental arginine appears to be metabolized to ornithine. Increased arginase enzyme activity in peripheral blood mononuclear cells may be a contributor.

Adolescent↗
PubMed2004

Regulation of arginase expression by T-helper II cytokines and isoproterenol.

BACKGROUND: Trauma causes a release of catecholamines, transforming growth factor-beta (TGF-beta), and T-helper II cytokines (TH2). Individually, these substances also induce arginase in macrophages. The purpose of this study was to determine the synergistic interactions between isoproterenol, TGF-beta, and TH2 cytokines on arginase expression in macrophages. METHODS: Confluent RAW 264.7 macrophages were incubated with various combinations of interleukins 4, 10, and 13 (IL-4, IL-10, IL-13), and TGF-beta with isoproterenol over 48 hours. Arginase activity, as well as arginase I expression by Western blot and reverse transcriptase-polymerase chain reaction, were measured. RESULTS: Although isoproterenol, IL-4, IL-10, and IL-13 individually induced arginase, significant synergy between the combination of isoproterenol with either TGF-beta or the TH2 cytokines was observed. All cytokines except IL-10 also induced arginase I protein and mRNA. Arginase II protein was detected in cells exposed to IL-10. CONCLUSIONS: We conclude that isoproterenol synergizes with IL-4, IL-13, and TGF-beta to increase arginase I mRNA and protein, as well as arginase activity in RAW 264.7 macrophages. Further, IL-10 synergizes with isoproterenol to increase arginase activity and arginase II protein. These synergistic mechanisms may compete with nitric oxide synthase for l-arginine substrate, thus shunting away available arginine from nitric oxide production and contributing to cellular immunosuppression observed after trauma.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2004

Hypothermia in the trauma patient.

Hypothermia is a common finding in severely injured patients. Historically described as a consequence of wartime casualties where cold exposure was common, this topic has resurfaced in the trauma literature because of the increasing recognition of the morbidity and mortality associated with hypothermia. Hypothermia, along with acidosis and coagulopathy, has been identified as a component of the "lethal triad" in injured patients, and has been shown to contribute to increased mortality in these patients. Decreases in core temperature during the course of initial evaluation and resuscitation are common, and can contribute to poor outcomes in the injured patient. As induced hypothermia has been shown to be beneficial in some clinical situations, recent animal studies have attempted to investigate whether hypothermia in the trauma patient has any beneficial effects. This review examines the incidence and pathophysiology of hypothermia, and discusses mechanisms of heat loss and rewarming techniques that can be utilized in the trauma patient.

Humans↗
PubMed2004

Defining and assessing tolerance in enteral nutrition.

Nutrition support has become widely recognized as an essential component of optimal care for acutely ill patients. Enteral nutrition is preferred over parenteral routes when possible. However, prescribed enteral nutritional regimens are sometimes met with side effects and even complications. These adverse events have been collectively termed "intolerance," and forms of intolerance occur in a spectrum from bothersome at least to life threatening when most severe. Here we discuss nutritional access and its maintenance, introduce and define intolerance, and then review the current literature with regard to principal forms of enteral nutrition intolerance.

Journal Article↗
PubMed2004

The open peritoneal cavity: etiology correlates with the likelihood of fascial closure.

The use of laparostomy in damage control surgery and uncontrolled intra-abdominal infection has been well described. We examined 71 patients who required laparostomy to see if trends in management and outcome could be identified based on the underlying disease state. The underlying etiology included gastrointestinal sepsis (n = 25), pancreatitis (n = 21), or trauma (n = 25). Pancreatitis patients required more operations per patient (P < 0.05). The likelihood and type of closure (fascial, mesh, or none) was related to the underlying etiology: trauma patients were more likely to have fascial closure (P < 0.02), patients with GI sepsis were more likely to require mesh closure, and pancreatitis patients were more likely to have no formal closure (P < 0.02). Only 29 per cent of patients achieved definitive fascial closure. Mortality in trauma patients was 20 per cent, 36 per cent for GI sepsis, and 43 per cent in patients with pancreatitis. Complications of laparostomy included enterocutaneous fistula (16.9%) and abscess formation (7%). Though the use of laparostomy has become more prevalent, it is still associated with significant hospital stay, morbidity, and mortality. In our study, the number of operations and likelihood of abdominal closure appears to correlate with the etiology of the underlying disease requiring use of laparostomy.

Abdominal Injuries↗
PubMed2003

Enteral nutrition in patients with an open peritoneal cavity.

Recent surgical advances have led to the increased survival of critically ill patients requiring postoperative nutritional supplementation. One technique, which has been increasingly used, is that of the open peritoneal cavity. In these cases, the peritoneum is left open, and the viscera are protected with a temporary dressing until the abdomen can be closed. The aim of this study was to evaluate the efficacy and tolerance of enteral nutrition in patients who need open peritoneal cavity management techniques. Patients at a tertiary referral center requiring the use of open peritoneal cavity management who received at least 4 days of enteral nutrition were included in the study. Retrospective data were collected on patients admitted between January 1999 and December 2000, and prospective data were collected on patients between January and May 2001. Energy expenditure and actual caloric and protein intake were determined in all patients. Prealbumin levels and nitrogen balance studies were analyzed when available. Intolerance, defined as diarrhea or gastric reflux, was also evaluated. Average daily total caloric intake was 77 +/- 27%, and average daily protein intake was 68 +/- 24% of estimated needs. Initial serum prealbumin levels were low and remained below normal but increased in some patients during the study. Average nitrogen balance studies from 3 patients was -15 +/- 9.7 g/d. Diarrhea and gastric reflux occurred in 42% and 36% of patients, respectively, and were easily treated. Enteral nutrition can be effectively used in patients requiring open peritoneal cavity management after laparotomy. Overall, enteral nutrition is relatively well tolerated in this patient population.

Journal Article↗