Neurotensin stimulation of mast cell secretion is receptor-mediated, pertussis-toxin sensitive and requires activation of phospholipase C.

Pretreatment of isolated rat serosal mast cells with U-73122, an aminosteroid inhibitor of phospholipase C, inhibited histamine secretion in response to neurotensin (NT). This inhibition reached a maximum after 1 h of pretreatment at 37 degrees C and was dependent upon the concentration of U-73122 (IC50 approximately 0.2 microM). The inactive analog, U-73343, had no effect on the secretory response to NT. Pretreatment of mast cells with U-73122 also blocked histamine secretion in response to substance P (SP), mastoparan (MP), compound 48/80, or amidated NT (NT-NH2). Stimulation of mast cells by NT was accompanied by a rise in the level of intracellular free calcium and a rapid (within seconds) increase in the level of inositol trisphosphate (IP3) which was inhibited by pretreatment of the cells with U-73122. Pretreatment of isolated mast cells with pertussis toxin (PTx) blocked histamine release in response to NT as well as to all peptides tested. PTx had no effect on histamine secretion elicited by anti-IgE stimulation of sensitized mast cells. Pretreatment of mast cells with SR 48692, a NT-receptor antagonist, had no effect on histamine release induced by MP. At a high concentration (100 nM) SR 48692 partially inhibited the response to NT-NH2. These results, together with our earlier findings with SR 48692, indicate that the signal transduction pathway in mast cells activated by NT requires a specific NT-receptor, the activation of phospholipase C, and the involvement of a PTx sensitive G protein. The peptides SP and MP, and compound 48/80, while also requiring the activation of PLC and a PTx sensitive G protein, are not inhibited by the NT-R antagonist, SR 48692, suggesting that they exert their actions either via a different mast cell receptor or via a receptor-independent mechanism.

Negative pressure pulmonary edema after acute upper airway obstruction.

STUDY OBJECTIVES: To review the clinical characteristics and the pathogenesis of negative pressure pulmonary edema, and to determine its incidence in surgical patients. DESIGN: Retrospective case-report study. SETTING: Operating room, postanesthesia care unit and surgical intensive care of a teaching hospital. PATIENTS: 30 surgical adult ASA physical status I, II, III, IV, and V patients who suffered from negative pressure pulmonary edema during the period 1992-1995. MEASUREMENTS AND MAIN RESULTS: This study showed a rapid onset of negative pressure pulmonary edema after acute upper airway obstruction, due mainly to laryngospasm in the postoperative period and to upper airway pathology in the preoperative period. Negative pressure pulmonary edema appeared more frequent in healthy (ASA physical status I and II), middle-aged and male patients, with a general incidence of 0.094%. The resolution was relatively rapid after reestablishment of the airway, adequate oxygenation, and positive airway pressure application. The clinical course was uncomplicated in all the patients. CONCLUSIONS: In this study, negative pressure pulmonary edema presented a relatively high incidence. Prevention, early diagnosis, and prompt treatment allowed a rapid and uncomplicated resolution.

Assessing health status in the elderly: the nutrition screening initiative.

The recent dramatic growth in the population aged 65 and over is projected to continue well into the 21st century. While improved health status of most aging Americans is also expected, such is not the case in certain vulnerable subgroups at risk for poor health. This includes older women; minority groups; those aged 85 and above; older persons with limited economic resources, those isolated from family and friends; and older persons with impaired physical, cognitive, or emotional status. These factors, plus the cost implications of caring for a rapidly aging population, provided the impetus for the development of the Nutrition Screening Initiative (NSI). Established in 1990, the goal of the NSI is to promote the incorporation of routine nutrition screening and nutritional care into America's health services delivery system. The NSI has devoted its activities toward increasing the awareness of nutritional factors as they relate to the older population.

Nutrition assessment practical approaches.

Because of the insidious nature of malnutrition in the elderly and its mimicking the usual aging process, it is important to recognize early warning signs of risks for malnutrition. Because the majority of individuals are encountered at times of a specific event (i.e., illness, injury, surgery, or annual examination) the physician needs to be cognizant of the triggers or alerts of poor nutritional health during history/physical and laboratory examinations for the particular event. Only then will early detection and applicable interventions provide a salutary paradigm shift towards prevention, whether primary, secondary, or tertiary. A high degree of suspicion, a thorough history, and physical examination coupled with pertinent laboratory data can identify the elderly at risk. Those in need of more comprehensive nutrition screen and assessment are examined with the tools developed by the NSI, which encompass not only the routine medical and dietary history and physical exam but also an expansive look at the older individual's psychosocial, functional, socioeconomic, and drug use aspects that are more indirect and significant determinants of risk. Based on parameters from a Level II Screen, measurable indicators are available that provide the nutrition assessment necessary for an overall healthcare plan of selected interventions. Future research should provide more practical, age, sex, and culturally specific nutrition parameters. The main factor in the implementation of a practical, comprehensive geriatric nutrition screening and assessment program is the clinician's imagination and motivation.

Nutrition support, supplementation, and replacement.

Nutrition support in acute, chronic, or home care settings can be implemented successfully by the well-informed primary care physician, who often is the first to identify poor nutritional health in his or her patients. Using established protocols for the identification or of risk factors and indicators of malnutrition, specific alerts to the need for nutrition support are presented. The logical approach to nutrition support interventions through four stages representing the gradual increase in complexity and cost, paralleling the progressive inability to use regular foods and the gastrointestinal tract are discussed. Specific, practical measures that can be recommended and implemented by the primary care physician managing the older person are presented. The ethical, legal, and home health aspects of nutrition support in the care of the older American by the primary care physician are also reviewed.

A prospective randomized trial comparing the silver-impregnated collagen cuff with the bedside tunneled subclavian catheter.

A prospective study was undertaken to compare the silver-impregnated collagen cuff (Vitacuff) with the bedside tunneled catheter. Fifty patients were randomly assigned to three groups: group I received triple-lumen catheters with Vitacuff application and a semiocclusive dressing material; group II received triple-lumen tunneled catheters with a semiocclusive dressing; and group III received triple-lumen tunneled catheters with collodion as a dressing material. In patients suspected of having central venous catheter sepsis, blood cultures were obtained through the catheter, the catheter was removed, and the tip was cultured semiquantitatively. Central venous catheter sepsis was defined as a positive catheter-tip culture and blood culture for the same organism. No catheter-related sepsis was seen in either the Vitacuff or the tunneled catheters with collodion dressing. In the tunneled catheters with semiocclusive dressing, there was one case of catheter-related sepsis and one case of insertion-site infection. There was also one insertion-site infection in the Vitacuff group, but there was no statistical difference in infection rates between the three groups.

Collodion as a safe, cost-effective dressing for central venous catheters.

Catheter-related sepsis continues to be a major problem with the use of central venous catheters. Controversy exists with respect to dressing material and frequency of dressing changes. Collodion is a solution of pyroxylin in a solution of 75% ether and 25% alcohol. Camphor and castor oil are added to create a flexible noncontracting dressing when applied to the skin. We retrospectively reviewed the charts of 34 patients requiring central venous catheters between 1986 and 1988. All catheters were placed via the subclavian approach. Collodion was used as a dressing on all patients. Dressings were not routinely changed. The catheters remained in position an average of 16.5 days. No insertion site became infected; one episode of catheter-related sepsis occurred, and two catheters were inadvertently dislodged. The overall incidence of catheter-related sepsis was 2.9%.

Nutritional considerations in the critically ill.

The total care of the critically ill patient must include attention to his nutritional status from the onset of illness. The essential role of protein in body functions must be stressed; unfortunately, it is this essential compartment that will be called upon for gluconeogenesis in stress or starvation. Simple technics of bedside nutritional assessment have been developed and should be familiar to all those who deal with critically ill patients. The multiple technics of optimal nutritional support should become a standard component of the therapeutic armamentarium of those who provide intensive care. The goal must always be to use the GI tract whenever possible, avoiding the numerous complications associated with intravenous nutrition. Care must be taken to avoid CO2 overload of an embarrassed respiratory system by the nutritional support. Whether nutritional or pulmonary support should take priority can usually be resolved by a team approach toward the patient. It is hoped that this superficial review of nutritional support will stimulate the desire for further knowledge of this rapidly changing and interesting aspect of critical care.

Medical, legal and ethical issues in critical care.

This report is intended to familiarize the reader with the current legislation concerning state definitions of death, the pertinent judicial decisions concerning termination of life support and the current status of medical/ethical committees. However, it is of paramount importance to all health care personnel to become involved in the resolution of these problems. Current information regarding legal clarity to these issues leaves much to be desired. Unless we wish major decisions that will affect us all to be decided by others, it is strongly suggested that we become directly involved in this process and accept the challenge and the opportunity to influence major legal, ethical, and medical decisions.

Nutritional assessment: indications and applications.

The application of objective measures of protein and caloric compartments as well as immunocompetence reveal that approximately 50 percent of hospitalized patients are malnourished. The performance of a nutritional assessment, by a joint effort of hospital personnel, in patients with subclinical or early clinical malnutrition obviates potential complications through early institution of nutritional support. Prudent, logical decisions based on objective data can then be made regarding future patient care resulting in decreased hospitalization, and lower septic and mortality rates.

Nutritional assessment in the community hospital.

Innovative technics in the recognition and treatment of malnutrition in hospitalized patients have blossomed in the past decade. A comprehensive nutritional assessment program available in larger institutions has been adapted for use in a community hospital. The procedure of nutritional assessment and its interpretation as employed in 50 hospitalized patients is presented, and therapeutic implications of the assessment are summarized.

The use of stapling devices in the management of postgastrectomy syndromes.

By the use of the stapling devices, a large spectrum of postgastrectomy syndromes can be managed with minimal manipulation and dissection, shortened operative time, decreased blood loss and spillage, and reduced morbidity while attaining uniformly good amelioration of symptoms. As others have recommended, the application of these techniques at the primary procedure should be considered. The author's experience in ten primary procedures has been quite gratifying to date.