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Biomedical subjects

R E Kron

Publications and source records attributed to R E Kron.

At least 19 recordsLinked to original sources
PubMed1998

The clinical utility of ambulatory blood pressure and heart rate monitoring in psychiatric inpatients.

Alterations in heart rate and blood pressure (BP) may occur in patients receiving psychiatric medication. Twenty-four-hour ambulatory blood pressure (ABP) monitoring was compared with nurses' conventional vital signs (CVS) for systolic (SBP) and diastolic (DBP) and heart rate (HR) measurements in psychiatric inpatients receiving multidrug treatments. Twelve consecutive subjects were enrolled. ABP monitoring and CVS measurements were concurrent but independent in each subject. Ambulatory BP monitoring recorded SBP, DBP, and HR thrice hourly from 6:00 AM to 10:00 PM and once hourly between 10:00 PM and 6:00 AM; CVS were obtained an average of 3.6 times/24 h. The frequency with which each BP and HR measurement method detected Level-1 (SBP 90 to 100 or 180 to 209 mm Hg; DBP 40 to 60 or 110 to 119 mm Hg; HR 50 to 60 or 110 to 119 beats/min) or Level-2 (SBP < 90 or > or = 210 mm Hg; DBP < 40 or > or = 120 mm Hg; HR < 50 or > or = 120 beats/min) events was determined, and disagreements between the two measurement systems were analyzed using the McNemar test for paired sample data. Ambulatory BP monitoring detected significantly more Level-1 and Level-2 events than CVS. A significant number of mostly low BP were documented by ABP monitoring and were undetected by the CVS obtained by the nursing staff. This finding may be of clinical relevance in view of the potential hemodynamic consequences of hypotension, especially in older patients receiving psychotropic multidrug treatment.

Adult↗
PubMed1988

Theory and design of disposable clinical blood viscometer.

A disposable clinical whole blood viscometer which can produce viscosity measures over a wide range of shear rates in a single rapid determination has been developed and is currently under test. The design is based upon the time varying flow of blood through a capillary. The flow is driven by the pressure in a fixed volume air chamber and transmitted to the sample through a compliant membrane. The time varying pressure in the air chamber is measured by a suitable transducer. The instantaneous shear stress of the blood in the capillary is proportional to the air pressure, while the instantaneous shear rate is proportional to the pressure-time derivative. Proper design ensures that the system operates as a first order dynamic system with flow resistance entirely determined by the nonlinear sample viscosity. By constructing the air chamber in two parts coupled by a quick disconnect fitting the design can allow for the blood-containing part of the instrument to be discarded, eliminating handling and cleaning of blood contacted components. The entire determination is completed in less than a minute, so that anticoagulants are not necessary. Tests on a prototype show that the instrument gives results in excellent agreement with those obtained on a cone-plate rheogoniometer.

Blood Viscosity↗
PubMed1984

Experimental hypervolemic hemodilution: physiological correlations of cortical blood flow, cardiac output, and intracranial pressure with fresh blood viscosity and plasma volume.

Rheological, cerebrovascular, and cardiovascular alterations induced by serial plasma volume (PV) expansion were evaluated in splenectomized dogs. Seven dogs received two infusions of autologous plasma within 120 minutes; each infusion equaled 20% of the respective dog's total blood volume (TBV). The PV increased 31% and then another 26% after the two respective infusions, and the hematocrit (Hct) was obligatorily decreased by 22% during the experiment. The fresh blood viscosity at the shear rate of 10 sec-1 varied inversely with the TBV and the PV and correlated directly with the Hct after these plasma infusions. Cardiac output (CO) increased 71% after the two infusions without significant alterations in mean arterial blood pressure. Additionally, CO was inversely related to both Hct and blood viscosity. Although the 15% rise in regional cortical blood flow (rCoBF) in the territory of the middle cerebral artery did not reach statistical significance, the rCoBF was related inversely to both Hct and blood viscosity and directly to TBV, PV, and CO after the plasma infusions. Cortical vascular resistance (CVR) decreased 18% after the two infusions. The CVR correlated inversely with PV and directly with Hct and blood viscosity. Our data suggest that hypervolemic hemodilution with expansion of PV increases CO more than cerebral blood flow in normal brain. Fresh blood viscosity seems to be a major factor determining CO and cerebral perfusion after IV expansion. This study adds support to the hypothesis that reductions of blood viscosity account for the direct relationship between cerebral blood flow and CO observed after intravascular volume expansion with hemodiluting agents. Hypervolemic hemodilution with plasma reduces CVR, possibly secondary to its effect on blood viscosity, and also raises intracranial pressure.

Animals↗
PubMed1982

Behavioral versus pharmacological treatments for essential hypertension--a needed comparison.

Comparison of mild-to-moderate essential hypertension patients treated for 6 weeks by antihypertensive medication versus metronome-conditioned relaxation versus biofeedback versus a mild exercise control procedure showed that those on medication achieved the greatest decrease in blood pressure. The relaxation and biofeedback groups decreased more than the mild exercise group, as predicted, but not significantly more. The differences in benefits of the groups were not a function of group differences in initial blood pressure levels nor in compliance. Nor did the groups differ in the side effects that are usually associated with medications. A second phase of 6 weeks with another treatment or combination of treatments did not add significantly. Some characteristics of patients moderately predicted treatment benefits, for example, high scores on the Jenkins Activity Survey Scales (1) [Type A, S or H], for the relaxation and biofeedback treated patients predicted which patients received greater benefits.

Adult↗
PubMed1976

Neonatal narcotic abstinence: Effects of pharmacotherapeutic agents and maternal drug usage on nutritive sucking behavior.

An uncoordinated and ineffectual sucking reflex is a major manifestation of neonatal narcotic abstinence and may have important consequences for the infant's subsequent well being. Measures of nutritive sucking were used to monitor the severity of neonatal narcotic abstinence in a series of infants born to narcotic-dependent mothers who were either attending the methadone clinic or else were "street addicts." In all these infants, sucking measures were significantly reduced relative to normal control subjects. Furthermore, the sucking behavior of infants born to mothers attending the methadone clinic was significantly more depressed than that of infants born to street addicts. In regard to the salutary effects of pharmacotherapy for neonatal narcotic abstinence, infants treated with paregoric approached normal control levels and showed significantly better sucking than those treated with phenobarbital or diazepam. The latter drug practically eliminated all spontaneous nutritive sucking behavior.

Diazepam↗
PubMed1976

A case of blood-illness-injury phobia treated behaviorally.

A patient with a 24-year history of blood-illness-injury phobia associated with bradycardia and syncope was treated behaviorally. He was taught to prevent bradycardia and resulting syncope occurring in the presence of phobic stimuli by provoking anger in himself using appropriate imagery. Within a few weeks, the patient was able to use the procedure successfully to prevent syncope in everyday situations. At 6 months follow-up he remained comfortable in the presence of previously phobic stimuli and he no longer needed to use self-induced anger to prevent syncopal episodes.

Adult↗
PubMed1975

Assessment and treatment of abstinence in the infant of the drug-dependent mother.

To accomplish the assessment and treatment of abstinence in the infant of the drug dependent mother, a scoring system has been devised for use as a clinical and research tool. The score monitors the passively addicted infant in a more comprehensive and precise way than has previously been described, and permits us to be more objective in our clinical estimates of the abstinence syndrome. Further, this scoring system has been used by relating it to the dosage schedule of phenobarbital or paregoric as part of an ongoing research project designed to test the comparative usefulness of recommended treatments for neonates with abstinence symptoms. It has been found useful also in following the progression or diminution of symptomatology before, during and after drug therapy. Moreover, the scoring system provides a basis for developing uniform criteria for the assessment and treatment of the neonate of the addicted mother.

Clinical Trials as Topic↗
PubMed1975

Neonatal abstinence syndrome: assessment and management.

A scoring system for the neonatal abstinence syndrome has been devised and implemented as both a clinical and investigative tool. The score monitors the passively addicted infant in a more comprehensive and objective fashion, and facilitates a more precise evaluation of the clinical status of the infant undergoing withdrawal. In addition, the scoring system has been applied in research designed to test the comparative usefulness of various pharmacologic agents currently recommended for the neonatal abstinence syndrome, and has been found useful in following the progression and diminution of withdrawal symptomatology before, during, and after therapy. Furthermore, the scoring system provides a basis ofr developing uniform criteria for the assessment and treatment of the neonate born to the addicted mother.

Administration, Oral↗
PubMed1975

The assessment of behavioral change in infants undergoing narcotic withdrawal: comparative data from clinical and objective methods.

Studies comparing objective measures of sucking with data from finegrained clinical assessments of the neonate have shown significant correlations between painstaking and time-comsuming clinical methods which may only be reliably applied by highly trained clinician-investigators, and the data generated by a simple technique which can be rapidly and precisely administered in the nursery by nurses or technicians. Within a few minutes the sucking instrument can generate data that explain 50% or more of the variance in certain relevant factors of the Brazelton neonatal neurobehavioral assessment scale, which in our hands requires the participation of two trained clinician-investigators for a period of almost one hour for each test and recording session. There are certain limitations to the information directly available from the sucking measures. Clinical observations must be made in order to correctly interpret some of the findings such as the biphasic relationship between irritability and sucking. For example, an infant may not suck at all because it is obtunded, or it may not suck because it is overexcited. In the case of irritability, sucking performance provides a measure of the magnitude, but not of the polarity of the CNS arousal sucking correlates directly and gives a good estimate of both polarity as well as amount of these behaviors. Objective measures of sucking behavior are a convenient and reliable means for measuring drug effects in the nursery and may be useful in regulating therapy of the newborn.

Arousal↗
PubMed1975

Narcotic addiction in the newborn: differences in behavior generated by methadone and heroin.

The nutritive sucking performance of congenitally addicted infants undergoing narcotic withdrawal was used to provide objective measures of adaptive behavior in a series of 50 infants born to mothers addicted either to heroin or methadone. Sucking rates as well as average pressures developed during sucking were significantly reduced for the addicted infants relative to a control group born to normal mothers and a second control group born to toxemic mothers. The subgroup of infants born to methadone-addicted mothers was significantly more depressed with regard to sucking behavior than the infants of heroin-addicted mothers. Furthermore, infants treated with paregoric (an opiate) for symptoms of the narcotic withdrawal syndrome showed significantly less depression of the sucking response than those treated with sedatives such as phenobarbital.

Adaptation, Physiological↗