A prospective study of the efficacy of the physician order form for life-sustaining treatment

OBJECTIVES: The Physician Orders for Life-Sustaining Treatment (POLST), a comprehensive, one-page order form, was developed to convey preferences for life-sustaining treatments during transfer from one care site to another. This study examined the extent to which the POLST form ensured that nursing home residents' wishes were honored for Do Not Resuscitate (DNR) and requests for transfer only if comfort measures fail. DESIGN: The study used chart record data to follow prospectively a sample of nursing home residents with the POLST. SETTING: Eight geographically diverse, long-term, adult-care facilities in Oregon in which the POLST was in use. PARTICIPANTS: Nursing home residents (n = 180), who had a POLST recording DNR designation and who indicated a desire for transfer only if comfort measures failed, were followed for 1 year. MEASUREMENTS: For all subjects: treatment and disposition after significant health status changes; orders for narcotics and for provision or limitation of aggressive interventions. For hospitalized subjects: diagnosis, medical interventions, and DNR orders. For those who died: cause and location of death, life-sustaining treatments attempted, and comfort measures provided. RESULTS: No study subject received CPR, ICU care, or ventilator support, and only 2% were hospitalized to extend life. Of the 38 subjects who died during the study year, 63% had an order for narcotics, and only two (5%) died in an acute care hospital. A total of 24 subjects (13%) were hospitalized during the year. Hospitalized subjects' mean length of stay was 4.9 days, and the mean rate of hospitalizations for all subjects was 174 per 1000 resident years. In 85% of all hospitalizations, patients were transferred because the nursing home could not control suffering. In 15% of hospitalizations (n = 4), the transfer was to extend life, overriding POLST orders. CONCLUSIONS: POLST orders regarding CPR in nursing home residents in this study were universally respected. Study subjects received remarkably high levels of comfort care and low rates of transfer for aggressive life-extending treatments.     

Activity of renin-angiotensin-aldosterone system (RAAS) and vasopressin level in patients with primary pulmonary hypertension

AIM: Assessment of RAAS and vasopressin in patients with primary pulmonary hypertension (PPH). MATERIALS AND METHODS: Activity of plasma renin (APR), angiotensin-converting enzyme (ACE), plasma levels of angiotensin II (AII) and vasopressin (VP), serum concentration of aldosteron (AS) were measured by radioimmunoassay and enzyme immunoassay in 21 PPH patients with circulatory failure (age 34.7 +/- 2.1 years), 11 patients with NYHA functional class II-III, 10 with class IV, and 10 control subjects (age 29.8 +/- 1.5 years). RESULTS: Compared to controls, 21 PPH patients had elevated RAAS parameters: APR up to 3.52 ng/ml/h (p < 0.05), activity of ACE up to 43.13 units, AII level up to 33.93 ng/ml (p < 0.01), AS up to 468.86 ng/ml (p < 0.01), VP up to 5.26 ng/ml (p < 0.001). Circulatory failure progression resulted in activation of all the RAAS components. This and VP activation was the greatest in PPH patients with ACE > 5 ng/ml/h. PPH patients with mean pressure in the pulmonary artery higher than 60 mm Hg demonstrated higher ARP, AS, VP, AII, ACE than those who had this pressure under 60 mm Hg. CONCLUSION: PPH patients display a noticeable activation of RAAS and VP. This activation seems to be secondary as the changes increase with elevation of the pressure in the pulmonary artery and aggravation of circulatory insufficiency. Plasma renin activity determines the degree of RAAS activation as a whole. The discovered activation of RAAS in PPH gives grounds for doubts in the validity of using ACE inhibitors in the treatment of PPH.     

Signal transduction pathways that regulate cell survival and cell death

Apoptosis or programmed cell death (PCD) is a physiological process critical for organ development, tissue homeostasis and elimination of defective or potentially dangerous cells in complex organisms. Apoptosis permits cell death without a concomitant inflammatory response in the surrounding tissues. The process of apoptosis depends on the reception of multiple extracellular and intracellular signals, integration and amplification of these signals by second messengers and finally, activation of the death effector proteases. Defects in control of apoptotic pathways may contribute to a variety of diseases including cancer, autoimmune and neurodegenerative conditions and AIDS. While many components of the regulatory network controlling apoptosis have been defined, the mechanisms of action and patterns of interaction of these factors remain controversial. This article summarizes some of the known aspects of signaling pathways involved in apoptosis.     

Effect of routine screening for Down's syndrome on the significance of isolated fetal hydronephrosis

OBJECTIVE: To determine the risk of Down's syndrome in fetuses with isolated hydronephrosis at 18-23 weeks in an unselected general population after routine screening for Down's syndrome, using first trimester nuchal translucency measurement and second trimester maternal serum biochemistry. POPULATION: All pregnant women undergoing a routine 18-23 week ultrasound scan, from a population who had been offered screening for Down's syndrome. SETTING: A district general hospital serving a low risk obstetric population. METHODS: Prospective study of all routine 18-23 weeks ultrasound scans. The prevalence of isolated hydronephrosis and Down's syndrome was determined and the relative risk for Down's syndrome was calculated for different ultrasound findings. RESULTS: 10,971 women were scanned at 18-23 weeks during the study period. Down's syndrome was diagnosed in 14 of 20 cases before this stage using first trimester nuchal translucency measurement and second trimester maternal serum biochemistry. Isolated fetal hydronephrosis was diagnosed in 423 pregnancies (3.9%); none of these pregnancies were affected by Down's syndrome. The relative risk for Down's syndrome was 0.18 (95% CI 0.06-0.53) for women with a normal scan (n = 9983). When multiple ultrasound markers were found (n = 565), the relative risk for Down's syndrome was 2.00 (95% CI 0.18-22.10) and 9.00 (95% CI 1.14-71.30) for all other aneuploidies. CONCLUSION: The finding of isolated fetal hydronephrosis does not significantly increase the age-related risk for Down's syndrome. The presence of multiple ultrasound markers is associated with an increased risk of aneuploidies other than Down's syndiome. These findings are explained by the reduced prevalence of Down's syndrome as a result of prior screening and diagnosis of this condition.     

Blastomycosis as an etiology of acute lung injury

Blastomyces dermatitidis, a dimorphic broad-based budding yeast endemic to the Mississippi River Valley region, is responsible for morbidity in humans via inhalation and dissemination. The response of acute lung injury, which produces an illness with serious morbidity and an approximately 50% mortality, uncommonly occurs. Diagnosis can be difficult, and a high index of suspicion should be maintained in endemic regions for patients with acute lung injury of uncertain etiology, especially if their condition deteriorates on broad-spectrum antimicrobial and antitubercular therapy and they have a previous insidious respiratory complaint and constitutional symptoms. Diagnosis should be aggressively pursued and treatment with amphotericin B (0.6 to 0.8 mg/kg/day) initiated as early as possible.     

Noninvasive determination of cardiac output using single breath CO2 analysis

OBJECTIVE: To examine the utility of single breath CO2 analysis as a noninvasive measure of cardiac output. SETTING: An animal laboratory in a university-affiliated medical center. DESIGN: A prospective, animal cohort study comparing 21 parameters derived from single breath CO2 analysis with cardiac output determined by an ultrasonic flow probe. SUBJECTS: Six healthy adult sheep. METHODS: The single breath CO2 analysis station consists of a mainstream capnometer, a variable orifice pneumotachometer, a signal processor, and computer software with capability for both on- and off-line data analysis. Twenty-one derived components of the CO2 expirogram were evaluated as predictors of cardiac output. Cardiac output was manipulated by successive injections of a hydraulic constrictor placed around the inferior vena cava. MEASUREMENTS AND MAIN RESULTS: Thirty-four measurements of cardiac output were available for comparison with derived variables from the CO2 expirogram. Stepwise linear regression identified two variables that were most predictive of cardiac output: a) the angle between the slope lines for phase II and III of the CO2 expirogram divided by the volume of CO2 per breath (angle/mL CO2); and b) the slope of phase II. The multivariate equation was highly statistically significant and explained 94% of the variance (adjusted r2 = .94, p < .0001). The bias and precision of the calculated cardiac output were .00 and .23, respectively. The mean percent difference for the cardiac output estimate derived from the single breath CO2 analysis station was 0.36%. CONCLUSIONS: Our data indicate that analysis of the CO2 expirogram can yield accurate information about the cardiovascular system. Specifically, two variables derived from a plot of expired CO2 concentration vs. expired volume predict changes in cardiac output in healthy adult sheep with an adjusted coefficient of determination of .94. Prospective application of this technology in the setting of lung injury and rapidly changing physiology will be essential in determining the clinical usefulness of the technique.     

The effect of a two-week anti-orthostatic hypokinesia on the cardiac function and on the latter''s regulation in monkeys

Medical practice guidelines are being developed rapidly and advocated as a crucial component in transforming and improving the delivery of health care services. However, little is known about the ability of hospitals to institute guidelines outside of experimental settings. This article approaches guideline implementation from the viewpoint of process innovation assimilation and presents specific recommendations for organizational tactics leading to successful implementation of practice guidelines.     

Putting reader roles to the test: an ethnomethodological approach

That readers read within roles has long been argued by literary theorists and more recently by technical communication theorists. Yet few scholars have attempted to put their theories to a test. The study reported in this paper attempts to do by using a conversation analysis tool called ethnomethodology. In an experimental setting, subjects were videotaped reading and responding to a set of instructions. Their responses indicate that: readers will often choose to play a role different from the one embedded in a text, especially if the text role offends them in some way; readers with similar education and interest may display different reader roles, making these roles difficult to predict; and within a single reading, a reader may change roles frequently. The paper concludes by discussing the implications of the findings and the appropriateness of ethnomethodology for reader-role research     

Design optimization of supersonic jet pumps using high fidelity flow analysis

Supersonic jet pumps are simple devices with no moving parts, where a high velocity (primary) flow is used to pump a second fluid. In this paper, Computational Fluid Dynamics (CFD) is combined with an optimization framework in order to develop a tool for the rapid generation of jet pump designs. A key feature of the problem formulation is the transformation of the jet pump design parameters in terms of geometric ratios. This approach dramatically reduces the number of unrealistic designs covered by the Design of Experiments. Optimal Latin Hypercubes for surrogate model building and model validation points are constructed using a permutation genetic algorithm and design points are evaluated using CFD. Surrogate models of primary and entrained flow rates are built using a Moving Least Squares approach. A series of optimizations for various pump sizes are performed using a genetic algorithm and Sequential Quadratic Programming, with responses calculated from the surrogates. This approach results in a set of optimized designs, from which pumps for a wide range of flow rates can be interpolated.