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Results for “physiologic variables”

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At least 127 records · Page 7Linked to original sources
PubMed2001

Factor analysis of quality of life, dyspnea, and physiologic variables in patients with chronic obstructive pulmonary disease before and after rehabilitation.

OBJECTIVE: To identify the relationships between quality of life (QOL) and the clinical state using factor analysis pre- and postrehabilitation. Patients with chronic obstructive pulmonary disease (COPD) suffer from a significant physiologic impairment associated with an altered QOL. Comprehensive rehabilitative programs, including exercise training, have beneficial effects on exercise tolerance and QOL for these patients. DESIGN: Factor analysis (n = 6) was conducted using the data of 32 patients with COPD. Patients had been evaluated for QOL using the Nottingham Health Profile (NHP), spirometric values, dyspnea, and the variables assessed by an incremental exercise test at three levels of activity. All measurements were obtained pre- and postrehabilitation. RESULTS: Factor analysis showed that the following two factors characterize the pathophysiologic condition of patients with COPD: (1) the specific cardiorespiratory responses to incremental exercise test and the spirometric values; and (2) the QOL results. The factor analysis results differed with the testing time (pre, post) and the level of activity. CONCLUSIONS: QOL, as evaluated by a generic questionnaire and the clinical state of patients with COPD, was independent; this independence characterized the pathophysiologic condition of our patients. Our results reinforce the usefulness of different types of evaluation, especially pre- and postrehabilitation, because they reflect independent benefits used to understand the success and follow-up of rehabilitative programs.

Aged↗
PubMed2000

Intraoperative physiologic variables and outcome in cardiac surgery: Part I. In-hospital mortality.

BACKGROUND: Risk stratification schemes have been developed to predict outcome of coronary artery bypass grafting (CABG) procedures, which are predominately based upon unalterable preoperative patient characteristics. The purpose of this study was to determine if minimum intraoperative hematocrit, maximum glucose concentration, mean arterial pressure on cardiopulmonary bypass, or duration of bypass influence risk-adjusted in-hospital mortality after CABG. METHODS: Outcome data from 2,862 CABG patients were merged with intraoperative physiologic data. A preoperative mortality risk index was calculated for each patient. Variables found significant (p<0.05) by univariate logistic regression were tested in a multiple variable model to determine risk-adjusted association with mortality. RESULTS: Overall mortality rate was 1.85%. The preoperative risk index was significantly associated with mortality (p = 0.0001). No significant association was present between mortality and intraoperative variables. Preexisting hypertension was an independent predictor of mortality after controlling for risk index and bypass duration. CONCLUSIONS: Preexisting hypertension proved to be an independent predictor of mortality in our patient population. This study found no evidence to support the hypothesis that mean arterial pressure less than 50 mm Hg, lower hematocrit, or elevated glucose while on bypass increases in-hospital mortality.

Aged↗
PubMed1995

Plasma free dopamine: physiological variability and pathophysiological significance.

Dopamine (DA) is the most abundant catecholamines in human plasma and exists mostly in the sulfo-conjugated form (DA sulfate), a biologically inactive metabolite. The paucity of unconjugated DA (PDA) in plasma throws doubt on its physiological significance. However, PDA, when measured with a highly sensitive radioenzymatic method, showed quite different features from norepinephrine and epinephrine in some types of clinical hypertension, lower in essential hypertension and higher in primary aldosteronism and pheochromocytoma. There was a weak but significant correlation between the values of PDA and DA sulfate measured in the same specimens, but DA sulfate was more susceptible to impaired renal function. Upright posture, high salt diets and an intravenous injection of metoclopramide (MCP, 10 mg), a DA receptor antagonist, induced a slight but significant increase in PDA in normal and hypertensive subjects. An intravenous dexamethasone (2 mg) caused a gradual increase in PDA over 150 min after medication, which was completely blocked by concomitant administration of alpha-methyl-p-tyrosine, a tyrosine hydroxylase inhibitor. The responses of PDA to both high salt diets and MCP were blunted in salt-sensitive patients with uncomplicated essential hypertension. The results suggest that DA is not only a precursor of norepinephrine biosynthesis but also plays an inherent role as an active neurotransmitter in the peripheral sympathoadrenal system, and that PDA is a sensitive marker of peripheral dopaminergic activity, which may operate to modulate the cardiovascular and endocrine functions and participate in the pathogenesis of some types of hypertension.

Dexamethasone↗
PubMed2006

A new concept for insect damage evaluation based on plant physiological variables.

The objective of this study was to determine the damage levels caused by Orthezia praelonga Douglas, 1891 and Leucoptera coffeella (Guérin-Mèneville 1842), on rangpur lime and Obatã coffee leaves, respectively. Measurements were based on a new concept for the evaluation of the following plant physiological parameters: photosynthesis, stomatal conductance, leaf temperature and transpiration, and internal concentration of CO2 (by infrared analyzer). A negative correlation between infestation level and photosynthesis was found, where the negative inflexion point of the curve was considered as a reference for damage levels. The control level for O. praelonga is below the 7-13% limit for damaged leaf area (40 to 70 scales per leaf), while for L. coffeella it is below the 26-36% limit for the same variable. Photosynthesis provided the best correlation for this type of analysis.

Animals↗
PubMed2006

Environmental correlates of physiological variables in marsupials.

We analyzed body temperature (T(b)), basal metabolic rate (BMR), wet thermal conductance (C(wet)), and evaporative water loss (EWL) of marsupials by conventional and phylogenetically corrected regression. Allometric effects were substantial for BMR, C(wet), and EWL but not T(b). There was a strong phylogenetic signal for mass and all physiological traits. A significant phylogenetic signal remained for BMR, C(wet), and EWL even after accounting for the highly significant phylogenetic signal of mass. T(b), BMR, C(wet), and EWL allometric residuals were correlated with some diet, distribution, and climatic variables before and after correction for phylogeny. T(b) residuals were higher for marsupials from arid environments (high T(a) and more variable rainfall). The fossorial marsupial mole had a lower-than-expected T(b) residual. The allometric slope for BMR was 0.72-0.75. Residuals were consistently related to distribution aridity and rainfall variability, with species from arid and variable rainfall habitats having a low BMR, presumably to conserve energy in a low-productivity environment. The nectarivorous honey possum had a higher-than-expected BMR. For C(wet), the allometric slope was 0.55-0.62; residuals were related to diet, with folivores having low and insectivores high C(wet) residuals. The allometric slope for EWL was 0.68-0.73. EWL residuals were consistently correlated with rainfall variability, presumably facilitating maintenance of water balance during dry periods.

Animals↗
PubMedDate not supplied

Physiologic studies of menstrual blood loss. II. Physiologic variables affecting the magnitude of menstrual blood loss.

The effect of marital status, age, parity, age at menarche, maternal size, arterial blood pressure, position and size of the uterus and hematologic parameters on the magnitude of menstrual blood loss was investigated in 745 randomly selected women in normal physiologic condition, aged 14-49 years, from a city population (Cairo). Menstrual blood loss was found to be related to parity, weight and body surface area and systolic and pulse pressure and to depend mainly upon the hematologic indices reflecting the state of iron balance and anemia in the body.

Adolescent↗
PubMed2002

Functional assessment of heart rate variability: physiological basis and practical applications.

The autonomic nervous system dynamically controls the response of the body to a range of external and internal stimuli, providing physiological stability in the individual. With the progress of information technology, it is now possible to explore the functioning of this system reliably and non-invasively using comprehensive and functional analysis of heart rate variability. This method is already an established tool in cardiology research, and is increasingly being used for a range of clinical applications. This review describes the theoretical basis and practical applications for this emerging technique.

Autonomic Nervous System↗
PubMed2000

Physiological variables during open chest cardiopulmonary resuscitation: results from a small series.

OBJECTIVES: To evaluate the efficacy of open chest cardiac compressions for the resuscitation of pre-hospital cardiac arrest patients presenting with non-shockable rhythms on arrival at the emergency department. DESIGN: Prospective observational study of outcomes and physiological parameters during open chest cardiac compressions for non-traumatic pre-hospital cardiac arrest. SETTING: Large accident and emergency department receiving pre-hospital cardiac arrest patients with pre-hospital advanced life support provided by ambulance service paramedics. SUBJECTS: All patients in whom open chest cardiac compressions were performed by the author (JCC) during the period from January to May 1998 (seven patients). INTERVENTIONS: Assessment of artificial pulse and blood pressure generated by open chest cardiac compressions, measurement of arterial blood gases, recovery of spontaneous cardiac output, recovery of spontaneous ventilatory efforts and survival to admission and to discharge. RESULTS: Artificial pulse and recordable non-invasive blood pressures were generated in all patients; PO2 was physiological or supra-physiological in all patients; PCO2 was physiological or subphysiological in all patients; pH and base deficit were not corrected in the five patients with repeated samples (including two receiving 50 mEq sodium bicarbonate); three patients recovered spontaneous cardiac output (ROSC); two patients recovered spontaneous respiratory efforts (unrelated to ROSC); no patients survived to admission. CONCLUSIONS: Open chest cardiac compressions provide effective perfusion, enabling correction of ventilation parameters and showing clinical signs of adequate perfusion. However, acidosis was not corrected and the use of 50 mEq sodium bicarbonate was ineffective.

Aged↗
PubMed1985

Myocardial stimulation threshold in patients with cardiac pacemakers: effect of physiologic variables, pharmacologic agents, and lead electrodes.

Many factors affect the threshold for myocardial stimulation in patients with cardiac pacemakers. The acute local tissue reaction at the electrode-myocardium interface accounts for early threshold rises and may be minimized by choice of specific electrodes (steroid-eluting or carbon-tip). Physiologic variations due to changes in autonomic tone (including eating, sleeping, and exercise) account for day-to-day fluctuations in pacing threshold. Electrolyte and metabolic abnormalities, especially hyperkalemia, alkalosis, acidosis, and hyperglycemia, increase the pacing threshold. Commonly used antiarrhythmic drugs (quinidine and procainamide) also increase pacing threshold. Patients with pacemakers who require antiarrhythmic agents or who have coincident metabolic or electrolyte disturbances should be observed closely for failure to capture. Management of failure to capture is directed at removing the inciting cause and attempting to lower the pacing threshold with isoproterenol, if the situation is urgent. Acute increases in pacing threshold immediately following pacing system implantation can be treated with corticosteroids. Increasing the energy output of programmable pacemakers, in specific circumstances, or insertion of a temporary pacemaker capable of delivering higher energy output than the implanted generator may also be successful.

Anti-Arrhythmia Agents↗
PubMed1994

[Evacuation proctography: physiological variability and clinical relevance of the anorectal angle and the position of the pelvic floor].

Evacuation proctography is an important imaging method for the investigation of abnormalities of defecation. For this procedure, the most commonly carried out measurements are the ano-rectal angle and the position of the pelvic floor. The given mean values and the physiologically acceptable deviations vary just as much as the perceived clinical value of these measurements. 173 evacuation proctograms were evaluated in a prospective study; the subjective abnormalities were correlated with clinical findings. No significant correlation between the measurements from the proctograms and the clinical findings could be determined. The clinical relevance of these measurements is, therefore, uncertain.

Adult↗
PubMed1989

Lack of effect of alpha-tocopherol and ascorbic acid on the response of some physiological variables to immobilization stress in rat.

The effect of alpha-tocopherol or ascorbic acid jointly and separately on the seric levels of adrenocorticotropin (ACTH) and corticosterone has been studied. ACTH response to stress is similar in all groups, whereas the corticosterone response is higher in the animals treated with alpha-tocopherol. Neither lactate response nor gastric ulceration caused by stress was influenced by the administration of alpha-tocopherol and/or ascorbic acid. These results suggest that free radicals might not be implicated in the control of the physiological response to stress.

Adrenocorticotropic Hormone↗