Arginine supplementation is well tolerated but does not enhance mitogen-induced lymphocyte proliferation in elderly nursing home residents with pressure ulcers.

BACKGROUND: Immune function declines with age, increasing risk for infection and delaying wound healing. Arginine enhances immune function and healing of standardized wounds in healthy elderly persons. The purpose of this study was to determine what level of arginine supplementation was orally and metabolically tolerated and effective in enhancing immune function in elderly persons with pressure ulcers. METHODS: Residents with one or more pressure ulcers were recruited from two local nursing homes. Subjects were randomized to receive 0 g (n = 10; age, 82 +/- 3 years), 8.5 g (n = 11; 81 +/- 3 years), or 17 g (n = 11; 87 +/- 2 years) of supplemental arginine each day for 4 weeks. Oral tolerance, ie, absence of nausea, vomiting, abdominal distention, or diarrhea, was assessed daily. Metabolic tolerance was assessed weekly by evaluating serum electrolytes. Lymphocyte proliferation to phytohemagglutinin and interleukin 2 production were measured at baseline and after 4 weeks of supplementation as indicators of immune function. RESULTS: Supplemental arginine significantly increased plasma arginine levels and was orally and metabolically tolerated with no complaints of abdominal distress or no clinically relevant changes in electrolyte levels among groups. Lymphocyte proliferation and interleukin 2 production were significantly different between nursing homes. When data from nursing homes were considered individually, arginine supplementation did not enhance the proliferative response. In subjects from nursing home 2 only, there was a 38% and 75% decrease (p < .05) in lymphocyte proliferation with 8.5 and 17 g of supplemental arginine, respectively. Interleukin 2 production was no different among supplementation groups. CONCLUSIONS: Pharmacologic doses of arginine were well tolerated but did not enhance lymphocyte proliferation or interleukin 2 production in nursing home residents with pressure ulcers. CLINICAL RELEVANCY: Enteral formulas supplemented with pharmacologic levels of arginine are frequently administered to elderly persons. This study demonstrates that the very old can tolerate these nitrogen loads if baseline renal function is normal and fluid intake is encouraged. Further research needs to be completed investigating the effect of arginine supplementation on immune function in this population before recommending arginine use.

Gut dysfunction in critically ill patients: a review of the literature.

BACKGROUND: Critically ill patients are susceptible to injury of the intestinal mucosa, changes in gut permeability, and failure of intestinal defense mechanisms. These conditions put the patients at risk for infection and multiple organ dysfunction syndrome. Specific therapies are needed to prevent gut failure during critical illness. OBJECTIVE: The purpose of this literature review is to provide a better understanding of the normal defense mechanisms of the gut and alterations associated with ischemia-reperfusion injury, risk of infection, and the link to multiple organ dysfunction syndrome in critically ill patients. Implications for early enteral stimulation and nutrition are included. METHODS: Medical and nursing studies on the intestinal response to critical illness and on the implications for early enteral nutrition in critically ill patients were reviewed. RESULTS: Significant advances have been made in understanding the normal defense mechanisms of the gut, including barrier and immune functions. Translocation of bacteria, mediators of the inflammatory response, and the microcirculation play a role in the response to critical illness. Enteral nutrition that includes glutamine and arginine enhances gut function and improves patients' outcomes in some clinical states. DISCUSSION: Further research should focus on specific strategies to enhance gut function, prevent loss of gut integrity, and improve patients' outcomes. These strategies include maintaining mesenteric blood flow, using gastric tonometry to assess oxygenation, inhibiting inflammatory mediators, and using growth factors to modify the metabolic state in patients who are critically ill.

Use of a clinical assessment tool for orally intubated patients.

BACKGROUND: Although oral hygiene is difficult to perform in orally intubated, critically ill patients, oropharyngeal status may be related to acquisition of nosocomial organisms and should therefore be addressed. OBJECTIVE: To develop a clinical tool for assessment of the mouth in orally intubated patients. METHODS: Sixteen orally intubated patients from one surgical and one medical intensive care unit were subjects. Demographic, clinical, and baseline oropharyngeal assessment data, including sputum and mouth cultures, were obtained on patient admission to the study and every other day. RESULTS: Oropharyngeal cultures of four subjects grew nosocomial bacterial organisms and of two subjects, fungal species. These same organisms were cultured from sputum specimens. Seven patients displayed severe xerostomia; 10 lip lesions were identified in nine subjects, 8 tongue lesions in nine subjects, and 8 mucosal lesions in nine subjects. CONCLUSION: Systemic oropharyngeal assessment in critically ill orally intubated patients may prevent more serious oropharyngeal infections.

Interruption of enteral feedings in head injured patients.

This study was undertaken to determine differences between caloric intake and requirements of critically ill, enterally fed, neurosurgical and neurotrauma patients and to determine the nature and frequency of interruptions in enteral feedings in this same population. This descriptive, prospective study was conducted in a surgical intensive care unit (ICU) in a university teaching hospital. The sample consisted of 52 mechanically ventilated, critically ill patients with a mean age of 48.96 years who were receiving enteral nutrition for at least two days. Basal energy requirements, daily nutritional intake and enteral feeding interruption characteristics were recorded for a total of 586 study days. Underfeeding due to interruptions occurred in the majority of patients for the first eight days following initiation of enteral feeding. Reasons for underfeeding were interruptions of continuous tube feedings due to medication administration via the feeding tube (31%), feeding tube displacement (27%), surgery (12%), ileus (9%), radiologic studies (9%), airway management (8%), bedside procedures (3%) and agitation (1%). The frequency of these enteral feeding interruptions may indicate inadequate nutritional support, highlighting the importance of performing daily nutritional monitoring to prevent malnutrition.

Adenosine protects against attenuation of flow reserve and myocardial function after coronary occlusion and reperfusion.

Total coronary artery occlusion and reperfusion result in attenuation of coronary blood flow reserve, regional myocardial dysfunction, and myocardial leukocyte infiltration. To examine the effects of intracoronary adenosine on these occlusion and reperfusion-induced perturbations, we subjected 14 dogs to total left anterior descending (LAD) coronary artery occlusion (1 hour) and reperfusion (1 hour). Seven dogs received adenosine (3.75 mg/min into the LAD distal to the occlusion) over a 1-hour period starting 5 minutes before reperfusion, and the remaining seven dogs received saline solution. One dog in each group died of ventricular fibrillation during coronary artery occlusion. Coronary flow reserve, measured as peak reactive hyperemia (10 and 20 seconds of total coronary artery occlusion) and peak coronary blood flow response to acetylcholine (0.01 to 1.0 micrograms) and nitroglycerin (5 to 25 micrograms), was impaired in the LAD region after LAD occlusion and reperfusion in the saline-treated dogs (all p < 0.01 vs before occlusion and reperfusion); LAD regional myocardial shortening fraction measured by ultrasonic crystals was also diminished after occlusion and reperfusion in saline-treated dogs (-5% +/- 1% vs 12% +/- 2%; p < 0.02). The adenosine-treated dogs showed total protection against loss of coronary flow reserve (peak reactive hyperemia and blood flow increase in response to acetylcholine and nitroglycerin; all p values not significant vs before LAD occlusion and reperfusion). LAD regional myocardial shortening fraction was also preserved in adenosine-treated dogs (9% +/- 2% vs 14% +/- 2%; p not significant). Myocardial myeloperoxidase activity, measured as an index of myocardial leukocyte infiltration, was greater (p < 0.02) in the LAD ischemic-reperfused regions than in nonischemic circumflex regions in the saline-treated dogs. A similar difference in myeloperoxidase activities in the reperfused and control regions was not observed in the adenosine-treated dogs. Thus adenosine protects against loss of coronary flow reserve and regional myocardial function in dogs subjected to coronary artery occlusion and reperfusion.

Predictors of burnout in critical care nurses.

OBJECTIVE: To develop a conceptual path model to explain the effects of a set of personal and occupational independent variables and the dependent variables of situational stress, job stress, job satisfaction, and job motivation on burnout among critical care nurses. DESIGN: A prospective descriptive study using a conceptual path model. SETTING: Nine hospitals in the northeastern, northwestern, north central, and southern regions of Florida. SAMPLE: Three hundred female critical care nurses employed in the nine hospitals who had worked full-time for at least 3 months. INSTRUMENTS: Subjects were administered a demographic and work survey instrument, the Daily Hassles Instrument, the Psychological Hardiness Test, the Job Diagnostic Inventory, and the Maslach Burnout Inventory. RESULTS: Path analysis of a burnout model resulted in a causal progression of situational stress, job stress, job satisfaction, and emotional exhaustion (which is a component of burnout). The results showed that commitment to career, health difficulties, psychologic hardiness, work load satisfaction, dealing with others at work, job security, and job satisfaction had a significant effect on emotional exhaustion. CONCLUSION: Seven variables had a significant effect on emotional exhaustion, which is a component of burnout, and explained 34% of the variance. The three most significant effects on emotional exhaustion were commitment to career, dealing with others at work and job satisfaction. Health difficulties, psychologic hardiness, work load satisfaction, and job security had a modest effect on emotional exhaustion.

Complications of enteral nutrition in hospitalized patients with artificial airways.

This study investigated complications of enteral feeding in hospitalized patients with artificial airways. A prospective chart review, using a descriptive design, was used in this study of 51 inpatients in a large southeastern teaching hospital. A low (5.9%) incidence of pulmonary aspiration was found. Diarrhea was also found to be an infrequent complication (2%). The most common complication in this sample was interruption in continuous tube feedings: 24 patients (47%) experienced such interruptions, resulting in potential underfeeding. Further investigation of the adequacy of nutrition of hospitalized tube-fed patients with artificial airways is necessary to determine clinical significance.

Job satisfaction among critical care nurses.

OBJECTIVE: To develop a conceptual path model to explain the effects of a set of personal and work-related independent variables and the dependent variables of situational stress, job stress and job motivation on job satisfaction among critical care nurses. DESIGN: A prospective descriptive study using a conceptual path model. SETTING: Nine hospitals licensed for at least 250 beds in the northeastern, northwestern, northcentral, and southern regions of Florida. SAMPLE: Three hundred female critical care nurses employed in the nine hospitals who had worked full-time for at least 3 months. MEASUREMENTS: Subjects were administered a demographic and work survey questionnaire, Daily Hassles Instrument, Psychological Hardiness Test and the Job Diagnostic Inventory. MAIN OUTCOME MEASURES: A conceptual path model was constructed to illustrate the effects of a set of personal and work-related independent variables and the dependent variables of situational stress, job stress and job motivation on job satisfaction. MAIN RESULTS: Path analysis of a job satisfaction model resulted in a causal progression of situational stress leading to either job stress or job motivation, both affecting job satisfaction. The results showed that job stress, job motivation, job expectations, meaningful work, knowledge of work results, commitment to career, health difficulties, task identity, supervision, dealing with others at work, opportunity for advancement, pay and job security had a significant effect on job satisfaction. CONCLUSION: Thirteen variables had a significant effect on job satisfaction and explained 63% of the variance. The four most significant effects on job satisfaction were opportunities for advancement, meaningfulness of work, pay and supervision. Commitment to the career, task identity and job security had a modest effect on job satisfaction.

Selected characteristics of nurses and physicians who have living wills.

The purpose of this report is to determine what characteristics are most closely associated with nurses and physicians who favor a living will. A statistical analysis called classification and regression trees (CART) was used on the data set from a previous study. The five predictor variables that were analyzed were chosen following incorporation of a univariate screening process in which variables were chosen by their association with the likelihood of signing a living will. In addition, variables that did not have complete data sets were not considered in the analysis. The CART procedure was then used to determine which of these five variables were considered significant predictors. Three variables were selected: religion, length of experience with the terminally ill, and nature of the relationship (professional or personal) with the terminally ill. The two nonsignificant and therefore rejected variables were education/occupation and current region of residence. Within the predictor variable religion, CART selected the grouping of values (agnostic/atheist and Christian/non-Christian) as the best predictor of nurses and physicians likely to sign a living will. The second best predictor variable identified was length of experience in providing care to at least one patient, family member, or friend who was terminally ill. The nature of the relationship (professional or personal) with the terminally ill was the next strongest predictor variable of signing a living will. No previous studies of the living will have used such multivariate techniques as CART analysis to predict the likelihood of a health care provider signing a living will.

Cardiac tamponade resulting from pneumopericardium: case report and implications for the critical care nurse.

Pneumopericardium resulting in cardiac tamponade may be caused by a variety of phenomena. The onset of cardiac tamponade can indicate the presence of a rare underlying condition. As a rare complication of mechanical ventilation and PEEP, our patient experienced pneumopericardium that resulted in cardiac tamponade. Perhaps the most crucial therapy of all is astute critical care nursing assessment of patients at risk of developing the life-threatening complication of cardiac tamponade. All critical care nurses should know the signs and symptoms of cardiac tamponade. Through accurate data collection, frequent monitoring, and immediate referral to the critical care team for medical diagnosis and treatment, a patient's death can be prevented.

Pulmonary aspiration in tube-fed patients with artificial airways.

Based on the results of this study, it appears that critically ill patients may receive nutritional supplements through the use of a small-gauge, flexible enteral feeding tube without significant danger of pulmonary aspiration. However, the potential for aspiration of tube feedings in any critically ill patient still exists, and further research in this area would contribute to a decrease in morbidity and mortality rates.

Prognostic efficacy of early clinical categorization of myocardial infarction patients.

To assess the prognostic validity of "low risk" classification at 24-36 hours as the basis for early transfer to an intermediate coronary care unit, Killip and Hutter/Sidel criteria for risk classicication were applied to 410 patients with acute myocardial infarction (MI) and prospectively compared with respect to mortality and morbidity. Six percent of "low risk" patients by the Killip classification subsequently died and were therefore misclassified. No patients in the group classified as "low risk" by the Hutter/Sidel criteria died; however, more than two and a half times as many potentially "low risk" patients were excluded from this group. With respect to morbidity, 35 of 87 patients (40%) classified as "low risk" by Hutter/Sidel criteria developed 43 major complications during their hospitalization. Nine of these patients developed 11 of the 43 complications (26%) on day six or later, and for five of these patients, this was their first major complication during hospitalization. This significant incidence of morbidity in "low risk" patients, despite their low mortality rates as a group, must be taken into account in developing intermediate coronary care units.

A nurse rehabilitator's impact on patients with myocardial infarction.

A nurse rehabilitator, supplementing routine physician/nursing coronary care unit (CCU) care, was found to be effective in increasing the return to work rate (p less than .05) and decreasing smoking (p less than .05) in a randomized trial of 102 patients with acute myocardial infarction (MI). These outcomes were thought to be due to the nurse rehabilitator's efforts in increasing patient knowledge of heart disease (p less than .01) and individual counseling.