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Biomedical subjects

Sharon L Merritt

Publications and source records attributed to Sharon L Merritt.

5 recordsLinked to original sources
PubMed2004

Pupil staging and EEG measurement of sleepiness.

The goal of this multi-method study was to examine the validity (accuracy) of the pupillometric Alertness Level Test (ALT) as a physiologic measure of sleepiness. The study used a pooled-time series-correlation design with 16 untreated narcolepsy (8 F, 8 M), 16 untreated obstructive sleep apnea (OSA) (7 F, 9 M) and 16 healthy control (8 F, 8 M) subjects. Participants underwent EEG/polysomnography testing using standard Multiple Sleep Latency Test electrode placement concurrent with the 15 min pupillometric ALT. EEG data were examined to determine if theta power (4-7 Hz) increased during 2-s periods of proportional pupil size decreases (pupil Stage 1, 95% or more of maximal pupil size to Stage 4, 65-74% of maximal size). Printed EEG records also were visually scored. Self-report sleepiness measures included the Pittsburgh Sleep Quality Index, the Profile of Mood States and the Epworth Sleepiness Scale. Within subject groups, theta power ratios significantly increased across pupil stages for the sleep disorder groups but not for controls (theta activity increased 42% for narcoleptic and 36% for OSA subjects). Between subject groups, the amount of theta activity was significantly greater for narcoleptic and OSA subjects than that for controls. Visual EEG scoring and self-report measures were usually consistent with objective findings. The ALT is convenient, easily repeatable and less technically demanding than EEG sleepiness measures, and it deserves more comprehensive testing as a valid measure of sleepiness.

Adult↗
PubMed2004

Sleep-disordered breathing and the association with cardiovascular risk.

Breathing-related sleep disorders, particularly obstructive sleep apnea, have been largely undiagnosed in people with cardiovascular disease, probably due to limited health care provider awareness of the association between the two conditions. Solid evidence is emerging that the apneic events that occur during sleep lead to acute and chronic hemodynamic changes during wake time, including elevated sympathetic tone, decreased stroke volume and cardiac output, increased heart rate, and changes in circulating hormones that regulate blood pressure, fluid volume, vasoconstriction, and vasodilation. Obstructive sleep apnea is associated with known cardiovascular risk factors such as obesity and hyperlipidemia, and is considered by many sleep clinicians to be an independent risk factor for hypertension. Additionally, sleep apnea has been implicated in the pathogenesis of heart failure and stroke. Treatment with positive airway pressure during sleep eliminates the apneic events and the ensuing acute hemodynamic changes. Improvements in daytime blood pressure and left ventricular function also have been noted in persons with hypertension and heart failure. Because effective treatment is available for sleep apnea, this condition needs to be diagnosed and treated in persons with cardiovascular disease.

Cardiovascular Diseases↗
PubMedDate not supplied

Critical thinking and clinical decision making in critical care nursing: a pilot study.

OBJECTIVE: This pilot study examined the relationship of education level, years of critical care nursing experience, and critical thinking (CT) ability (skills and dispositions) to consistency in clinical decision making among critical care nurses. Consistency was defined as the degree to which intuitive and analytical decision processes resulted in similar selection of interventions in tasks of low and high complexity. DESIGN: The study was nonexperimental and correlational. SAMPLE: Critical care nurses (n = 54) from adult critical care units in 3 private teaching hospitals. The majority of nurses held a BSN or MSN and had an average of 9 years of direct clinical experience in the care of the critically ill. RESULTS: Decision-making consistency decreased significantly between low-complexity and high-complexity tasks. Both intuitive and analytical decision processes produced clear intervention selections in the low-complexity task, although the analytical process resulted in a more complete specification of interventions. In the high-complexity task, however, only the intuitive process resulted in a clear, plausible, and safe specification of interventions. Education and experience were not related to CT ability, nor was CT ability related to decision-making consistency. Only greater years of critical care nursing experience increased the likelihood of decision-making consistency. CONCLUSIONS: Overall, intuitive decision processes resulted in more clinically consistent selection of interventions across tasks. More investigation is needed to examine the influence of decision heuristics, and the conceptualization and measurement of CT abilities among practicing nurses.

Adult↗
PubMedDate not supplied

The coronary artery bypass experience: gender differences.

OBJECTIVE: The primary purpose of this study was to examine differences between women and men on physical, social and psychological domains of health quality of life before, 1 month after, and 3 months after coronary artery bypass surgery. DESIGN: A prospective, longitudinal design was used. SETTING: The study was conducted at a Midwestern, 500-bed community hospital with an ongoing cardiothoracic surgical program. PARTICIPANTS: Forty pairs of women and men matched on age within 5 years and body surface area within 0.1m 2. INSTRUMENTS: The physical, social and psychological domains of health quality of life were assessed using the following instruments: Ferrans and Powers Quality of Life Index, Specific Activity Scale, Symptom Scale, Profile of Mood States, Overall Health Rating Index, and Personal Resource Questionnaire. RESULTS: Both women and men improved on physical and psychological measures following coronary artery bypass surgery. Compared with men, women reported more shortness of breath and depression and lower ratings of activity, vigor, and overall health. Measures of social support yielded little information. CONCLUSIONS: Despite matching for age and body surface area, women did not have as favorable an outcome after surgery as men. Continued research needs to further examine the interaction of physical outcomes and depression in women after coronary artery bypass surgery.

Chi-Square Distribution↗