Sharon L. Merritt

Differences in reported sleep need among adolescents

Increased lifestyle demands and reduced sleep are reported to result in daytime sleepiness and impaired functioning for teenagers. A sample of 612 freshman urban high school students completed a questionnaire describing their sleep patterns and problems, along with sociodemographic information, daily activities, pubertal development, depressive mood, and morning-evening preference. About 63% of the respondents felt they needed more sleep on weeknights (MS group), experienced sleepiness that interfered with their schoolwork, and had problems with sleeping. The other group reported they got sufficient sleep on weeknights (SS group) and did not experience sleepiness problems to the same degree. However, both had similar weeknight sleep and daily activity patterns. The MS group reported an ideal sleep time of 9.2 h, about 2 h more than they were getting and 1 h more than the SS group ideal, and had a higher preference for later bed and waking times. In our sample, individual differences in biologic sleep need and quality of sleep may be emerging as early as 14 years of age.

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.

Church‐based education: An outreach program for African Americans with hypertension

The goals of this education outreach demonstration study were to prepare a cadre of registered nurses (RN) as Church Health Educators (CHE), and to test the efficacy of a hypertension (HBP) education and support program in African American (AA) churches for persons with HBP in managing blood pressure (BP). In this two-phase study, RNs were prepared as CHEs in phase 1 and a convenience sample of 97 subjects with HBP was taught by the CHEs in phase 2. The interventions content included the bases of HBP and HBP management strategies, and was taught in eight 1-hour sessions. Using a pre-test-post-test design, data on knowledge, social support and BP were collected at baseline (pre), post-intervention (post1) and 3 months post-intervention (post2). Major findings include: (1) there was a significant increase in knowledge scores from pre to post1 and post2 (P < or = 0.0001; F = 95.08; df = 1.79); (2) education, age and number of years with HBP explained 49% of the variance associated with HBP knowledge; (3) systolic BP (SBP) and mean arterial BP (MAP) significantly decreased from pre to post1 and post2 (SBP-p < or = 0.0001, F = 18.35, df = 1.91; MAP-p < or = 0.0001, F = 17.80, df = 1.86); (4) DBP significantly decreased from pre to post1 only (p < or = 0.008, F = 17.48, df = 1.91); and (5) relationships were found between social support and DBP, and social support and MAP. Issues that emerged from this study with implications for outreach programming include recruitment and retention, randomization, selective sampling, intervention design and use of volunteers.

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.

Artifact management in pupillometry

A detailed analysis of pupillometry data collection and handling procedures in the initial study uncovered a number of problems that threatened the integrity of the data, including improper procedures, lack of adherence to data collection rules, and inaccurate mathematical calculation of results. Substantial modifications in procedures were made to improve data collection and reduce artifact. With the increased sampling rate from 5 to 60 Hz and use of a videotape playback system, a more accurate and thorough method for removing artifact from pupillometry data was demonstrated in a subsequent study. The automated cleaning algorithm system proved to be efficient at detecting and removing artifact, as well as alerting users to artifact that might not be replaceable automatically. Additionally, this system provided another method of data storage, videotape, which was beneficial in reviewing the pupil behavior that was digitally recorded. Now that procedures for collecting pupil data and managing artifact have been objectively tested, steps can be taken towards establishing pupillometry as a reliable and valid screening tool for detecting excessive sleepiness.

Neurological pupillary noise in narcolepsy

SUMMARY Pupillometry has a long but inconclusive history as a means of measuring human alertness. Spontaneous pupillary oscillations in narcoleptics and the sleep deprived are a recognized but quantitatively elusive indication of alertness. Stimulation of the pupillary light reflex (PLR) has provided contradictory or confusing indications of alertness levels. Results from 10 diagnosed narcoleptics and 10 control subjects in which the PLR system was stimulated and a reliable (90%) discriminator derived for classifying narcoleptics and controls was reported. Random pupillary oscillations, which is called pupillary noise to distinguish these oscillations from spontaneous ones, were estimated from continuous pupil diameter recordings using a recursive least squares method applied to a subject–specific PLR system model. Pupillary noise sum of squares indicate that narcoleptics have significantly (P < 0.005) less PLR noise than controls. This difference was attributed to supranuclear inhibition of randomly active Edinger‐Westphal neurons long hypothesized to be the source of random papillary oscillations. This inhibition also has been suggested as a cause of PLR sensitivity to nocturnal sleep quality so it may be that these findings apply to the sleep deprived and not just specifically to narcoleptics.

Using recursive parameter estimation for sleep disorder discrimination

The human pupillary light reflex has long been studied as a typical biological nonlinear system. We have used a sinusoidal non-harmonic signal as the input light stimulus and pupil diameter as the output of the system. A recursive least square method is then used to estimate the measured pupil diameter in terms of the input light. With a good estimate, the underlying dynamical behavior of the system would be captured by the estimated parameters. Thus we modeled the estimated parameters as ARIMA processes. Then the residual noise associated with the ARIMA models was examined and revealed that people with narcolepsy had considerably lower sum-square-error than people without this sleep disorder (controls). This method turns out to be a relatively simple and fast test procedure for narcolepsy discrimination.

Measurement of Functional Ability in Patients with Coronary Artery Disease

The purpose of this study was to examine measures of functional ability in a group (n=60) of cardiac patients undergoing treadmill exercise tests. Functional ability was defined as the degree to which the individual is able to perform physical activity in the absence of symptoms. Instruments used were the Modified Harvard Alumni Scale (MHAS), the Symptom Scale (SS) comprised of the following subscales: angina (AS), shortness of breath (SOBS), and fatigue (FS); the overall Health Rating Index (OHRI); and the Goldman Specific Activity Scale (SAS). Concurrent validity was supported by the fact that the instruments were correlated with metabolic equivalents achieved on the treadmill. Correlations were: MHAS (r=.34, P<.01), SS (r= -.67, p<.01), AS (r= -.54, p<.01), SOBS (r= -.41, p<.05), FS (r= -.56, P<.001) and the OHRI (r=.45, p<.001). Reliability was determined using Cronbachs, alpha and were: SS= .92, AS=.87, SOBS=.86, FS=.85 and OHRI=.88. Findings support the need for testing and evaluation of instruments measuring functional ability in diverse cardiovascular populations.

Discrete-time model to test links between EEG power and pupil diameter measured by infrared cameras

Using infrared sensitive cameras and on-line image processing, pupil diameters of awake, eyes-open subjects were measured. Concurrently, electroencephalography (EEG) was monitored and power in the delta (0.5-4Hz), theta (4-8Hz), alpha (8-12Hz), sigma (12-16Hz), beta1 (16-26Hz), and beta2 (26-50Hz) bands were calculated. Pupil diameter and EEG power measured were found to be significantly correlated. Other EEG measures including relative beta (defined here as [power of 16-50Hz]/[power of 4-50Hz]) and centroid frequency of the 4-50Hz band were also found to be significantly related to pupil diameter.

Use of recurrence plots in the analysis of pupil diameter dynamics in narcoleptics

Recurrence plots were used to evaluate pupil dynamics of subjects with narcolepsy. Preliminary data indicate that this nonlinear method of analyses may be more useful in revealing underlying deterministic differences than traditional methods like FFT and counting statistics.