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Results for “physiologic variables”

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PubMed1985

Clearance of 99m-technetium-labelled DTPA in asbestos-exposed subjects without clinical or radiological evidence of interstitial lung disease.

The half-time clearance of an inhaled aerosol of 99m-technetium-labelled diethylene triamine pentacetate from lung to blood (T1/2LB) was measured using a gamma camera in 20 non-smoking subjects (mean age 54, range 40-69 years) with previous occupational asbestos exposure, but no clinical or radiological evidence of asbestosis, and 20 non-smoking normal subjects (mean age 54, range 40-62). Mean T1/2LB was 44.7 minutes (range 12-102) in exposed subjects, significantly less than 57.2 minutes (range 30.5-109) in normal subjects (P less than 0.05). There was no correlation between age and T1/2LB in either group. In exposed subjects T1/2LB showed a weak rank correlation with the membrane component of DLco (Dm) (r = 0.40, P less than 0.05) but no significant correlation with FVC, TLC, DLco, Kco, resting Pao2 or change in Pao2 on exercise. In six exposed subjects T1/2LB was shorter than in any of the normal subjects. These six did not differ from the other 14 exposed subjects in any physiological variables. T1/2LB is abnormal in some asbestos-exposed subjects without clinical, radiological or physiological evidence of asbestosis. Follow-up will show whether it is an early indicator of development of interstitial lung disease.

Adult↗

PubMed2001

Subfornical organ neurons projecting to paraventricular nucleus: whole-cell properties.

The subfornical organ (SFO) has been repeatedly identified as a CNS site that plays a critical role in sensing multiple physiological variables of the "milieu interieur" and, through efferent projections to other CNS sites, initiating physiological responses to change. Many recent in vitro patch-clamp studies have examined the cellular mechanisms underlying the sensory abilities of these specialized CNS neurons. The primary limitation of these studies, however, has been the inability to identify homogeneous groups of SFO neurons for such investigation. We report here the development of techniques to permit patch clamp recording from dissociated SFO neurons identified according to their in vivo projection site. SFO neurons were labeled by injection of fluorescently labeled, retrogradely transported microspheres into the hypothalamic paraventricular nucleus (PVN) 3 days prior to cell dissociation. Patch-clamp recordings from these SFO-PVN neurons revealed both sodium currents, potassium currents, action potentials, input resistance and membrane potential which were all similar to SFO cells prepared from animals with no prior tracer injection. Labeled SFO-->PVN cells were also found to be osmosensitive and responsive to angiotensin II, suggesting specific functional roles for this anatomically defined group of SFO neurons. Intriguingly, our post hoc analysis also demonstrated that all labeled neurons demonstrated a unique electrophysiological profile dominated by a large transient potassium conductance such that the transient/sustained potassium current ratio, or degree of inactivation was, on average, greater than 4.0. Utilization of these tracing techniques to permit the in vitro recording from cells with known in vivo connections will permit study of intrinsic mechanisms that underlie physiological responses of anatomically defined populations of neurons.

Action Potentials↗

PubMed1995

Surfactant protein A predicts survival in idiopathic pulmonary fibrosis.

The purpose of this study was to determine if the measurement of surfactant protein A (SP-A) in bronchoalveolar lavage (BAL) fluid predicts survival in patients with idiopathic pulmonary fibrosis (IPF). We performed BAL on 44 patients with IPF and 33 healthy volunteers. SP-A and total phospholipid (PL) were measured in the surfactant pelleted by centrifugation and expressed as a ratio to account for differences in the alveolar surface area sampled. The mean SP-A/PL was lower in patients with IPF than in healthy volunteers (31.8 +/- 2.8 versus 63.9 +/- 6.4 micrograms/mumol, p = 0.006) and in patients who died within 2 yr than in those who survived (23.4 +/- 2.6 versus 37.5 +/- 4.2 micrograms/mumol, p = 0.015). Using Cox's proportional hazard model, we found that SP-A/PL modeled continuously was associated with survival time (p = 0.002). The 5-yr survival of patients with SP-A/PL above the median level for all patients with IPF (29.7 micrograms/mumol) was more than twice that of patients below the median (68 versus 30%, p = 0.007). SP-A/PL improved upon prediction of survival modeled by most routine physiologic variables with the exception of percent predicted TLC or the multifarious clinical-radiographic-physiologic score (CRP). Cellular analysis of lavage did not predict survival in this cohort of patients. We conclude that SP-A/PL is a biochemical marker in lavage that predicts survival in patients with IPF.

Adult↗

PubMed1994

Dissociation of enzyme oligomers: a mechanism for allosteric regulation.

Most enzymes exist as oligomers or polymers, and a significant subset of these (perhaps 15% of all enzymes) can reversibly dissociate and reassociate in response to an effector ligand. Such a change in subunit assembly usually is accompanied by a change in enzyme activity, providing a mechanism for regulation. Two models are described for a physical mechanism, leading to a change in activity: (1) catalytic activity depends on subunit conformation, which is modulated by subunit dissociation; and (2) catalytic or regulatory sites are located at subunit interfaces and are disrupted by subunit dissociation. Examples of such enzymes show that both catalytic sites and regulatory sites occur at the junction of 2 subunits. In addition, for 9 enzymes, kinetic studies supported the existence of a separate regulatory site with significantly different affinity for the binding of either a substrate or a product of that enzyme. Over 40 dissociating enzymes are described from 3 major metabolic areas: carbohydrate metabolism, nucleotide metabolism, and amino acid metabolism. Important variables that influence enzyme dissociation include: enzyme concentration, ligand concentration, other cellular proteins, pH, and temperature. All these variables can be readily manipulated in vitro, but normally only the first two are physiological variables. Seven of these enzymes are most active as the dissociated monomer, the others as oligomers, emphasizing the importance of a regulated equilibrium between 2 or more conformational states. Experiments to test whether enzyme dissociation occurs in vivo showed this to be the case in 6 out of 7 studies, with 4 different enzymes.

Allosteric Regulation↗

PubMed2003

Repeated treadmill walks affect physiologic responses in children with cerebral palsy.

PURPOSE: To determine whether physiologic responses during treadmill walking in children with cerebral palsy (CP) are affected by repeated walking bouts on different days, and whether effects are different at different speeds. METHODS: Three girls and five boys (9.2-15.7 yr, 23.3-64.4 kg) with mild CP received 12-15 min of treadmill walking practice and had their fastest walking speed (FWS) determined during an introductory visit. During each of three subsequent visits (day 1, day 2, day 3), subjects walked for 3 min at 60, 75, and 90% FWS. Resting physiologic measures were taken on day 1. RESULTS: From day 1 to day 3, net ventilation ([OV0312]E), and net heart rate (HR) at 90% FWS decreased by 3.6 L.min-1 and 8 beats.min-1, respectively. There were no differences between day 1 and day 2 or day 1 and day 3 for any other physiologic variable at any speed. Day 3 was less than day 2 for net HR (60% FWS) and, independent of speed, net [OV0312]O2 (per kilogram of body mass and per stride) and net energy expenditure (kJ.min-1). Between-day reliability (R) of physiologic responses was > or = 0.95, except respiratory rate (R = 0.75). Intrasubject, between-day variability for the [OV0312]O2 measures was 7.6-12.9%. CONCLUSION: Because there were no day 1 to day 3 reductions in metabolic variables, day 1 to day 3 reductions at 90% FWS in net HR may reflect decreased emotional stress over time and reductions in net [OV0312]E, an uncoupling of [OV0312]O2 and [OV0312]E. Despite between-day differences, reliable net physiologic and stable net metabolic variables may be collected in subjects with mild CP after one treadmill walking practice session.

Adolescent↗

PubMed1986

Conjunctival oxygen tension monitoring during hemorrhage.

Placement of an unheated, miniaturized oxygen electrode against the palpebral conjunctiva permits noninvasive measurement of tissue oxygen tension without the heating artifacts present with transcutaneous monitoring. In this study, the relationship between conjunctival oxygen tension (PcjO2) and standard cardiorespiratory variables was examined in a sequential hemorrhage model. PcjO2 was among the first set of physiologic variables that differed significantly from control values during hemorrhage. PcjO2 was the first noninvasively measured parameter to become abnormal. In particular, PcjO2 fell at an earlier point and more rapidly than did blood pressure. Conjunctival oxygen monitoring may have a useful clinical role in the early identification of blood loss.

Animals↗

PubMed2002

Fractal or biologically variable delivery of cardioplegic solution prevents diastolic dysfunction after cardiopulmonary bypass.

OBJECTIVE: To determine whether myocardial protection is improved by restoring physiologic variability to the cardioplegia pressure signal during cardiopulmonary bypass, we compared cardiac function in pigs in the first hour after either conventional cold-blood cardioplegia (group CC) or computer-controlled biologically variable pulsatile cardioplegia (group BVC). METHODS: Invasive monitors and sonomicrometry crystals were placed, and cardiopulmonary bypass was initiated. The aorta was crossclamped, and cold blood cardioplegic solution was infused intermittently through the aortic root with either conventional cardioplegia (n = 8) or biologically variable pulsatile cardioplegia (n = 8; mean pressure, 75 mm Hg for 85 minutes). The crossclamp was released, cardiac function was restored, and separation from cardiopulmonary bypass was completed. With stable temperature and arterial blood gases, hemodynamics and systolic and diastolic indices were compared at 15, 30, and 60 minutes after cardiopulmonary bypass. RESULTS: Diastolic stiffness doubled from 0.027 +/- 0.016 mm Hg/mm (mean +/- SD) at baseline to 0.055 +/- 0.036 mm Hg/mm (P =.003) at 1 hour after bypass in group CC, associated with increased left ventricular end-diastolic pressure from 9 +/- 2 to 11 +/- 2 mm Hg (P =.001), mean pulmonary artery pressure from 14 +/- 2 to 20 +/- 3 mm Hg (P =.003), and serum lactate levels from 2.0 +/- 0.5 to 5.6 +/- 2.3 mmol/L (P =.008). Systolic function was not affected. In group BVC diastolic stiffness, left ventricular end-diastolic pressure, and pulmonary artery pressure values were not different from control values at any time after bypass, and serum lactate levels were significantly less than with conventional cold blood cardioplegia. Peak pressure variability with biologically variable pulsatile cardioplegia fit a power-law equation (exponent = -3.0; R(2) = 0.97), indicating fractal behavior. CONCLUSION: Diastolic cardiac function is better preserved after cardiopulmonary bypass with biologically variable pulsatile cardioplegia and fractal perfusion. This may be attributed to enhanced microcirculatory perfusion with improved myocardial protection. A model supporting these results is presented.

Animals↗

PubMed1997

Computer simulation of the effects of alterations in blood flows and body composition on thiopental pharmacokinetics in humans.

BACKGROUND: Understanding the influence of physiological variables on thiopental pharmacokinetics would enhance the scientific basis for the clinical usage of this anesthetic. METHODS: A physiological pharmacokinetic model for thiopental previously developed in rats was scaled to humans by substituting human values for tissue blood flows, tissue masses, and elimination clearance in place of respective rat values. The model was validated with published serum concentration data from 64 subjects. The model was simulated after intravenous thiopental administration, 250 mg, over 1 min, to predict arterial plasma concentrations under conditions of different cardiac outputs, degrees of obesity, gender, or age. RESULTS: The human pharmacokinetic model is characterized by a steady state volume of distribution of 2.2 l/kg, an elimination clearance of 0.22 l/min, and a terminal half-life of 9 h. Measured thiopental concentrations are predicted with an accuracy of 6 +/- 37% (SD). Greater peak arterial concentrations are predicted in subjects with a low versus a high cardiac output (3.1 and 9.4 l/min), and in subjects who are lean versus obese (56 and 135 kg). Acutely, obesity influences concentrations because it affects cardiac output. Prolonged changes are due to differences in fat mass. Changes with gender and age are relatively minor. CONCLUSIONS: The physiological pharmacokinetic model developed in rats predicts thiopental pharmacokinetics in humans. Differences in basal cardiac output may explain much of the variability in early thiopental disposition between subjects.

Adult↗

PubMed2003

A molecular perspective of human circadian rhythm disorders.

A large number of physiological variables display 24-h or circadian rhythms. Genes dedicated to the generation and regulation of physiological circadian rhythms have now been identified in several species, including humans. These clock genes are involved in transcriptional regulatory feedback loops. The mutation of these genes in animals leads to abnormal rhythms or even to arrhythmicity in constant conditions. In this view, and given the similarities between the circadian system of humans and rodents, it is expected that mutations of clock genes in humans may give rise to health problems, in particular sleep and mood disorders. Here we first review the present knowledge of molecular mechanisms underlying circadian rhythmicity, and we then revisit human circadian rhythm syndromes in light of the molecular data.

Animals↗

PubMed1999

Pro- and anti-inflammatory cytokines during acute severe pancreatitis: an early and sustained response, although unpredictable of death. Parisian Study Group on Acute Pancreatitis.

OBJECTIVES: To define the pro- and anti-inflammatory cytokine response during acute severe pancreatitis and to evaluate its predictive value on hospital mortality. DESIGN: Prospective, multicenter study. SETTING: Nine multidisciplinary intensive care units (ICUs). PATIENTS: Fifty patients with a diagnosis of acute pancreatitis who were admitted to the ICUs during a 14-month period were prospectively enrolled. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma concentrations of tumor necrosis factor (TNF)-alpha interleukin (IL)-1beta, IL-6, IL-10, IL-1 receptor antagonist (IL-1ra) were determined at the inclusion and during the ICU stay at Days 1, 3, 8, and 15. The patient population was analyzed by age, gender, previous health status, preexisting organ dysfunction, and type of acute pancreatitis. Physiologic variables were measured at inclusion and during ICU stay to calculate the new Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and the number of organ system failures. Prognostic factors were determined by univariate methods and stepwise logistic regression analysis. Fifty patients were included, among whom 34 at the time of the ICU admission. Preinclusion symptom history was < or = 48 hrs in 78% of the patients. Eleven patients (22%) died during their hospital stay. At inclusion, 46 of 50 patients had elevated IL-6 serum levels (1512 +/- 635 pg/mL; normal value < 10 pg/mL), 36% of the patients had raised TNF-alpha concentrations, and all patients had an anti-inflammatory response (IL-10, 92 +/- 15 pg/mL [normal value < 10 pg/mL]; and/or IL-1ra, 7271 +/- 2530 pg/mL [normal value < 200 mg/mL]). During the follow-up period, pro- and anti-inflammatory cytokines remained elevated in at least 75% of the population. Positive correlations were found between inclusion pro- (IL-6) and anti-inflammatory cytokine concentrations at Day 1 (IL-10, IL-1ra; p < .0001) and between cytokines levels and the Simplified Acute Physiology Score II. While hospital mortality was linked to six factors in univariate analysis (age, cirrhosis, delay between hospitalization and ICU admission, severity of illness, and IL-10 and IL-6 plasma levels) when using stepwise logistic regression, only severity scoring indexes were predictive of death. CONCLUSIONS: During acute severe pancreatitis, the pro- and anti-inflammatory cytokine response occurred early and persisted in the systemic circulation for several days. Although associated with the patient's severity at inclusion and outcome, cytokine plasma concentrations were unable to predict death accurately in individual patients. If confirmed, these results should be taken into consideration when selecting patients who are apt to benefit from new therapies aimed at modifying the immune inflammatory response.

APACHE↗

PubMed2007

Toward individualized treatment: prediction of anticancer drug disposition and toxicity with pharmacogenetics.

A great deal of effort has been spent in defining the pharmacokinetics and pharmacodynamics of investigational and registered anticancer agents. Often, there is a marked variability in drug handling between individual patients, which contributes to variability in the pharmacodynamic effects of a given dose of a drug. A combination of physiological variables, genetic characteristics (pharmacogenetics) and environmental factors is known to alter the relationship between the absolute dose and the concentration-time profile in plasma. A variety of strategies are now being evaluated in patients with cancer to improve the therapeutic index of anticancer drugs by implementation of pharmacogenetic imprinting through genotyping or phenotyping individual patients. The efforts have mainly focused on variants in genes encoding the drug-metabolizing enzymes thiopurine S-methyltransferase, dihydropyrimidine dehydrogenase, members of the cytochrome P450 family, including the CYP2B, 2C, 2D and 3A subfamilies, members of the UDP glucuronosyltransferase family, as well as the ATP-binding cassette transporters ABCB1 (P-glycoprotein) and ABCG2 (breast cancer resistance protein). Several of these genotyping strategies have been shown to have substantial impact on therapeutic outcome and should eventually lead to improved anticancer chemotherapy.

Animals↗

PubMed1987

Physiological factors affecting salivary flow rate, oral sugar clearance, and the sensation of dry mouth in man.

This paper discusses methods for collection of both whole saliva and individual gland secretions, the normal ranges of salivary flow rate, the effects of physiological variables which influence flow rate, and the role of saliva in oral sugar clearance. The physiological basis for the sensation of dry mouth is discussed, and a new concept is advanced which states that the sensation of dry mouth will occur when the salivary flow rate is less than the sum of the rates of water absorption and evaporation from the mouth. In a study of the effects of anticholinergic agents on salivary flow, the subjects experienced the sensation of dry mouth when the normal flow rate of unstimulated saliva was reduced by from 40 to 50%.

Absorption↗

PubMed1992

Measurement, analysis, and modelling of the caloric response. 1. A descriptive mathematical model of the caloric response over time.

A mathematical model for describing the caloric response over time offers many important advantages over the commercially-available qualitatively-fitted curves that are now used by the clinician for evaluating caloric results. In this report advances in the development of a nonlinear least-squares mathematical model are discussed and the roles and derivations of fitting parameters and curve-derived indices are outlined. This model provides a rigorous and objective description of the caloric response in its entirety with four continuous parameters. These fitting parameters make it possible to 1) describe individual caloric responses precisely and uniquely, 2) compare pairs of individual caloric responses or groups of caloric responses statistically, 3) extract information not previously available, 4) quantify variability within the caloric response, and 5) model physical properties of the caloric stimulus and physiological variables affecting the caloric response. Results from this model are compared with the results from our earlier models and with traditional multiparameter caloric results.

Caloric Tests↗

PubMed2003

Bioimpedance-derived differences in cardiac physiology during exercise stress testing in low-risk chest pain patients.

BACKGROUND: Little has been written about the utility of thoracic electrical bioimpedance (TEB)-derived cardiac physiologic variables in evaluating patients with low-risk chest pain syndromes. Noninvasive bioimpedance can monitor cardiac physiology while a patient is performing an exercise stress test. In addition, the demographics of patients with chest pain, the incidence of coronary artery disease (CAD), and the methods used for evaluation have well-documented sex differences. OBJECTIVE: The objectives are to show that there are different cardiac physiologic responses to exercise stress test in Chest Pain Evaluation Unit patients with and without true CAD that could be used to stratify patients and that there is a sex difference in TEB results. METHODS: Patients 18 to 65 years of age with low-risk chest pain were eligible. Patients were attached to the TEB throughout the exercise stress test procedure. Heart rate (HR) was monitored. Primary dependent variables were TEB-measured cardiac output (CO, L/min) and stroke volume (SV, ml) at peak exercise. Secondary variables were TEB-measured ejection fraction (%), end-diastolic volume (EDV, ml), ventricular ejection time (ms), and thoracic fluid index (omega) at peak exercise. Outcome variables were either proved CAD or patient sex. CAD was proved by angiography, stress scintigraphy, or stress echocardiogram. Results were compared using a Student's t test assuming equal variances, with significance considered at a P < 0.05, and 95% confidence intervals were calculated for significant results. RESULTS: Nine patients had proved CAD, 82 patients did not. Forty-three women and 48 men were included in the study. At peak exercise, patients with CAD had a significantly smaller increase in EDV than patients without CAD (32.8 +/- 59.5 ml versus 89.3 +/- 101.8 ml) without a significant change in CO, SV, or HR. At peak exercise, women had a significantly smaller increase in CO and SV without a significant change in HR. In addition, women had a significantly smaller increase in EDV. CONCLUSION: When compared with patients without CAD, patients with CAD have a significantly smaller increase in EDV and a trend toward the same effect in CO and SV. Women have significantly smaller increases CO, SV, and EDV compared with men. Because there were no differences in HR, using HR as the sole end point would miss these differences. TEB is a practical means of measuring these variables.

Adolescent↗

PubMedDate not supplied

Detecting and assessing severity of coronary artery disease in humans.

Quantitation of stenosis severity has become an essential part of cardiac diagnosis and therapy, not only in research but also in clinical practice. Since our introduction of the concept 15 years ago, arterial coronary flow reserve for assessing effects of coronary narrowing has evolved into two independent but complementary measurements: coronary flow reserve and stenosis flow reserve. Coronary artery flow reserve and/or myocardial perfusion reserve takes into account not only stenosis geometry but also collateral function and physiologic conditions of perfusion pressure, vasomotor tone, coronary venous pressure, and myocardial vascular bed size. Coronary artery flow reserve is measured invasively by flowmeter or by Doppler catheter. Its noninvasive equivalent is myocardial perfusion reserve, assessed by myocardial perfusion imaging with positron emission tomography before and after intravenous dipyridamole with hand grip stress. Both have been experimentally and clinically validated for identifying and/or quantifying severity of coronary artery disease. By either invasive or noninvasive methods, coronary artery or myocardial perfusion reserve may be subcategorized as either absolute flow or perfusion reserve (max flow/resting flow) and/or relative flow or perfusion reserve (max flow through stenotic artery/max flow through normal artery). Absolute flow reserve depends not only on stenosis severity but also on unrelated physiologic parameters such as aortic pressure and the vasodilatory state of the distal coronary vascular bed; in contrast, relative flow reserve is independent of these physiologic variables and reflects stenosis severity alone. Stenosis flow reserve is invasively determined by automated, quantitative coronary arteriography accounting for all stenosis dimensions and is independent of ambient physiologic conditions such as pressure, vasomotor tone, or other variables affecting the distal coronary vascular bed.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiocardiography↗

PubMed1995

Biological rhythmicity in preterm infants prior to discharge from neonatal intensive care.

OBJECTIVE: The study of biological rhythms and the influence of environmental factors in the timing and synchronization of different rhythmic events have important implications for neonatal health. Preterm infants in the neonatal intensive care unit (NICU) are deprived of the patterned influences of maternal sleep, temperature, heart rate, and hormonal cycles. The impact of the NICU and nursing interventions on the development of the circadian system was studied in 17 stable preterm infants in the Intermediate Intensive Care Nursery at Stanford University for three consecutive days at about 35 weeks postconceptional age. OUTCOME MEASUREMENTS: Rectal temperature, abdominal skin temperature, heart rate, and activity were simultaneously recorded at 2-minute intervals during each 3-day study by a small microcomputer (Vitalog). RESULTS: Very low amplitude circadian rhythms were found for rectal and skin temperatures (maximum range 36.8 to 37.0 degrees C); population mean values for heart rate (158 bpm) and activity (3.5 counts per 2-min bin) did not differ significantly as a function of time of day. Rectal temperature, averaged in 6-hour bins over the 24-hour day as a function of both postconceptional age and postnatal age, was significantly higher during the first part of the circadian cycle. In all infants, rhythmicity in each variable was dominated by ultradian periodicities that were coincident with feedings and related interventions; moreover, several physiological variables charted during feeding differed significantly from values obtained during periods in which caregiving interventions did not occur. CONCLUSION: Quantitative data on the preterm infant circadian system may facilitate evaluation of factors that improve therapeutic responses, recovery, and outcome of neonatal intensive care patients.

Birth Weight↗

PubMed1981

Genetic variation and phenotypic correlations of food consumption of laying hens corrected for body weight and production.

1. On samples from two brown-egg strains between 1967 and 1979, "residual" food consumption (i.e. food consumption corrected for body weight, weight change and egg mass) of laying hens was investigated with respect to variation between sire families and phenotypic correlations with production traits, egg traits, morphological and physiological variables. A similar residual food intake (corrected for body weight and body-weight gain) was obtained for samples of males in some years. 2. Highly significant differences between sire families were observed for residual food consumption in both strains for females and in one strain for males. 3. In females, highly significant positive phenotypic correlations were found in both populations for residual food intake with wattle length and shank temperature, and in one population with shank length and width. On the whole, a negative correlation was observed with egg-shell thickness. For two variables recorded only in one strain, proportion of broken eggs yolk: albumen ratio, there were highly significant positive correlations. 4. For males also, wattle length and shank temperature were positively correlated with residual food intake. 5. The physiological meaning and possible use of correlated variables as criteria for indirect selection for food efficiency of layers are discussed.

Animals↗

PubMed2006

Vascular evaluation in laryngeal diseases: comparison between contact endoscopy and laser Doppler flowmetry.

OBJECTIVE: To determine the efficacies of 2 methods for evaluating vascular changes in laryngeal diseases. DESIGN: Prospective comparative study. SETTING: University hospital. PATIENTS: Twenty-four adults planning to undergo laryngomicrosurgery for unilateral lesions in their vocal cords. INTERVENTION: Vascular evaluation was performed using contact endoscopy and laser Doppler flowmetry during laryngomicrosurgery. MAIN OUTCOME MEASURES: Morphological and physiological variables of the vascular changes. RESULTS: Contact endoscopy examinations revealed changes in the fine vascular network patterns in the vocal cords. Hypervascularity was present in patients with polyps but not in those with nodules, and the degree of vascularity was variable in patients with malignant neoplasms. Patients with papillomas and patients in the postradiation therapy group showed hypovascularity with losses in the capillary network. Laser Doppler flowmetry revealed high mean blood flows in patients with polyps, dysplasia, and malignant neoplasms, whereas patients with papillomas and those in the postradiation therapy group had low blood flows. The variables measured by laser Doppler flowmetry and endoscopy were strongly correlated. CONCLUSION: Evaluations of morphological and physiological changes of vascularity in laryngeal diseases are important for understanding their pathophysiology, and combining contact endoscopy and laser Doppler flowmetry is useful in such evaluations.

Adult↗