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Biomedical subjects

J Lamphere

Publications and source records attributed to J Lamphere.

17 recordsLinked to original sources
PubMed1995

Anterograde perfusion in acute limb ischemia secondary to vascular occlusive cardiopulmonary support.

Cardiopulmonary support (CPS) can resuscitate a patient with circulatory collapse during high-risk interventional procedures, although vascular complications may accompany its use. We report a patient with cardiogenic shock secondary to myocardial infarction who required extended CPS support associated with acute infarct-related coronary artery angioplasty and stent placement. Leg ischemia due to an occlusive cannula was resolved using a percutaneous anterograde perfusion device. In general, such devices may have application in patients dependent on mechanical support associated with limb ischemia.

Acute Disease↗
PubMed1990

The chronic efficacy of midazolam.

The chronic efficacy of midazolam 15.0 mg was studied in 2 male and 10 female subjects. Only subjects with a complaint of sleep latency insomnia which was verified by polysomnography were included in the study. Following a screening and adaptation period, subjects spent 3 consecutive nights in the laboratory during the weeks of the study. Placebo was administered 15 min before lights out on the initial 8 and final 2 nights, and midazolam for the intervening 35 nights. Midazolam significantly reduced sleep latency parameters and significantly increased total sleep time the entire 5 weeks of nightly administration. No within-night rebound insomnia, residual daytime effects, or rebound effects upon discontinuation appeared.

Adult↗
PubMed1989

Fragmented sleep, daytime somnolence and age in narcolepsy.

This study examined whether narcoleptics experience an age-related increase in nocturnal sleep disturbance and, if so, what impact that disturbance has on daytime sleepiness. To evaluate these questions, the records of 228 patients diagnosed as narcoleptic were assessed. Total sleep time (TST) and sleep efficiency (SE) significantly decreased, and wake during sleep (WDS), number of awakenings, and percentage of stage one significantly increased across the decades. This indicates an age-related elevation in sleep fragmentation. Daytime sleepiness, however, did not exhibit age effects. These data further support the theory that narcolepsy is a basic neural defect not confounded by excessive daytime sleepiness secondary to sleep fragmentation.

Adult↗
PubMed1989

Recovery of alertness after CPAP in apnea.

Excessive daytime sleepiness is the most common symptom in OSAS. Administering CPAP improves breathing during sleep. We evaluated the time course of the recovery of alertness following CPAP therapy in OSAS patients. Thirty-nine patients with OSAS were treated with CPAP and evaluated after one, 14, or 42 nights of treatment, 13 patients being randomly assigned to each group. All received a diagnostic polysomnogram and MSLT before treatment. The three groups had similar baseline values for nocturnal respiratory disturbance, oxygenation during sleep, fragmentation of sleep, and level of EDS. CPAP treatment was associated with a significant improvement in sleep-related respiration, oxygenation, and sleep fragmentation. The EDS showed significant improvement after one night, and further significant improvement after 14 nights, but no further significant improvement after 42 nights. The differential rate of improvement in nocturnal parameters compared with that of primary complaint of EDS suggests that OSAS patients experience a chronic functional sleep loss. As with sleep deprivation, recovery of alertness in OSAS requires several nights of normal sleep.

Adult↗
PubMed1989

The dose effects of zolpidem on the sleep of healthy normals.

This study determined the dose effects of zolpidem in 12 healthy males with normal sleep patterns. Subjects spent 7 weeks, 3 consecutive nights per week, in the laboratory and had a 4-night washout between treatments. The first week was a screening and adaptation week. Then subjects received zolpidem (2.5, 5.0, 7.5, 10.0, or 20.0 mg) or placebo on the first two nights for each of the next 6 consecutive weeks. Treatments were organized in a Latin square design and administered in a double-blind fashion. On the third night of each treatment, subjects always received placebo. The 5.0 mg and larger doses of zolpidem significantly decreased latency to persistent sleep and wake before sleep. Sleep maintenance measures were not affected by zolpidem. The 7.5 mg and higher doses of zolpidem significantly increased total sleep time. The only significant sleep stage effect was a decrease in percent of rapid eye movement sleep at only the 20 mg dose. No consistent discontinuation effects were found. Zolpidem was hypnotically active at doses as low as 5.0 and 7.5 mg, and sleep stage effects occurred only at the 20 mg dose, thus separating the dose range of hypnotic and sleep stage effects.

Adult↗
PubMed1988

Increased daytime sleepiness enhances ethanol's sedative effects.

Thirty healthy men, 21 to 35 years old, received either 8.7, 13.0 or 17.4 mmol/kg (0.4, 0.6, or 0.8 g/kg) ethanol after 8 hours time in bed (TIB), one night of 5 hours TIB, and four nights of 5 hours TIB. Ethanol, administered as 80-proof vodka mixed 1:4 with tonic water, was consumed over 30 minutes (0900 to 0930 hours). Sleep latency was measured at 1000, 1200, 1400, and 1600 hours using standard sleep laboratory methodology. Breath ethanol concentration (BEC) was determined prior to each latency test. Mean latency to sleep on the four tests decreased from day 1 (8 hours TIB) to day 5 (fourth day of 5 hours TIB). On day 1 mean latency after 8.7 mmol/kg differed from that after 17.4 mmol/kg, with the 13.0 mmol/kg latency intermediate between the other two. On day 2 and day 5 during sleep restriction these dose differences were diminished. Latency on day 5 after 8.7 mmol/kg was similar to that of 13.0 mmol/kg on day 2, which was similar to that of 17.4 mmol/kg on day 1. The BEC did not change from day 1 to day 5 and significant dose differences between each dose remained consistent from day to day. These data show that increased basal levels of sleepiness enhance ethanol's sedative effects for even moderate ethanol doses.

Adult↗
PubMed1987

Experimental sleep fragmentation in normal subjects.

Recent research has suggested that sleep fragmentation in the absence of sleep loss is an important cause of excessive daytime sleepiness in certain clinical populations (e.g., sleep apnea syndrome or periodic leg movements). This study experimentally varied the number and rate of arousals in sleep to define more clearly the relation of sleep fragmentation and daytime sleepiness. Five male subjects participated in the study. Data from each were recorded for three consecutive nights (one baseline followed by two experimental nights) under three experimental conditions. All nocturnal polysomnograms were followed by a Multiple Sleep Latency Test (MSLT) the next day. The experimental conditions consisted of three different schedules of arousal produced by series of tones presented to subjects over headphones. The MSLT showed statistically significant changes after two nights of fragmented sleep, but the three fragmentation schedules did not differ from each other. Arousal threshold also changed significantly with sleep fragmentation from night one to night two.

Adolescent↗
PubMed1986

Sleep-wake abnormalities in narcolepsy.

To evaluate the degree to which sleep (REM vs. NREM) intrudes into wake and wake intrudes into sleep in narcolepsy, 103 patients with narcolepsy were compared to 105 patients with other diagnoses of disorders of excessive sleep (DOES). Narcoleptic patients had more frequent REM onsets on the multiple sleep latency test (MSLT) and nocturnal polysomnograms. But the MSLT latencies to REM versus NREM in narcoleptic patients did not differ. Nocturnal measures of REM pressure, percentage of REM, and REM latency excluding the REM onsets, did not differ among patient groups. With respect to the intrusion of wake into sleep, narcoleptic patients had more and longer awakenings compared with other DOES patients, but the distribution of wake into REM and NREM sleep did not differ among groups. These data suggest that narcolepsy is not exclusively a REM-related disorder, but involves an inability to sustain a specific neural state for periods comparable to those in normal subjects or other DOES patients.

Adult↗
PubMed1986

Chronic hypnotic efficacy of estazolam.

The chronic hypnotic efficacy of estazolam 2.0 mg was studied in five female and seven male subjects. Subjects with a complaint of insomnia verified by polysomnography were included in the study. Following a screening and adaptation period, subjects spent two consecutive nights a week in the laboratory. The protocol for medication was placebo for weeks 1, 2, 9 and 10 and estazolam for weeks 3-8. Estazolam 2.0 mg significantly improved sleep onset and total sleep time for up to six weeks of nightly administration without consistent recovery effects upon discontinuation.

Adult↗
PubMed1986

Dose effects of temazepam tablets on sleep.

The dose effects of temazepam tablets (15 and 30 mg) were studied at two sleep centres in 48 volunteers who had objective polysomnographic evidence of sleep onset insomnia. Volunteers slept in the laboratory, retiring at their usual bedtime after taking placebo or temazepam 30 min earlier, and were monitored for 8 h using standard polysomnographic techniques. Acute (nights 5-7) and short term (nights 11-13) temazepam, both 15 and 30 mg, improved the sleep of these volunteers by reducing sleep latency and increasing sleep time compared to the placebo baseline (nights 2-4). Dose differences were found primarily on the measurement of sleep staging, with 30 mg having a greater or more consistent effect than 15 mg. No residual effects were observed on the basis of questionnaires and objective tests of performance and no consistent evidence of disturbed sleep after discontinuing treatment was seen.

Adult↗
PubMed1985

Eligibility requirements in hypnotic trials.

Forty-eight patients complaining of insomnia were studied at two sleep laboratories using an identical protocol to evaluate hypnotic efficacy. All met the screening requirement of a mean sleep latency of 30 min or greater on 3 laboratory nights following an adaptation night. Of these patients 34 still complaining of insomnia were screened a second time 2 to 6 months later. Sixteen of the 34 failed the second screen. Sleep parameters for the 34 on screen 1 compared with screen 2 were the same except for sleep latency (the eligibility criteria), which was significantly shorter. There was no evidence of a systematic difference between laboratories, a change in procedure from screen 1 to 2, or a systematic loss of patients from screen 1 to 2. The data show that the statistical phenomenon of regression toward the mean must be considered in designing hypnotic efficacy studies.

Adult↗
PubMed1984

Sleep fragmentation and daytime sleepiness.

It has been noted that clinical populations complaining of excessive daytime sleepiness (EDS) frequently have disrupted or fragmented nocturnal sleep. The relation between sleep fragmentation and daytime sleepiness has not been systematically studied. This study was designed to use correlational techniques evaluating the relation between these variables in patients complaining of EDS, patients complaining of insomnia, and asymptomatic controls. The four groups studied included patients complaining of EDS with sleep apnea (n = 15) or with periodic leg movements (n = 15), patients complaining of insomnia (n = 15), and healthy volunteers with no sleep complaint (n = 10). One night of polysomnography followed by a Multiple Sleep Latency Test was obtained for each subject. Each recording was evaluated using standard criteria and also by a four-level arousal scoring system. Across all subjects, the total number of arousals correlated significantly with sleepiness index (r = 0.48, p less than 0.001). Closer analysis of the data shows that, depending upon the sleep complaint, different types of arousals are predictive of degree of daytime sleepiness. It is concluded that the number and type of nocturnal arousals play an important role in subsequent daytime sleepiness.

Adult↗
PubMed1984

Temazepam's efficacy in patients with sleep onset insomnia.

The hypnotic efficacy of temazepam capsules (30 mg) was studied in twelve patients who had objective polysomnographic evidence of sleep onset insomnia. Patients slept in the laboratory, retiring at their usual bedtime after taking placebo or temazepam 30 min earlier, and were monitored for 8 h using standard polysomnographic techniques. Acute (nights 5-7) and chronic (nights 11-13) temazepam improved the sleep of these patients by reducing sleep latency and increasing sleep time compared to the placebo baseline (nights 2-4). No detrimental effects on daytime function the following morning were observed using questionnaires and objective tests of performance. No consistent evidence of disturbed sleep after discontinuation of treatment was obtained over three recovery nights.

Adult↗
PubMedDate not supplied

Hospital conversion trends.

This DataWatch presents information on the extent, geographic distribution, and other issues related to hospital conversions during the 1980s and 1990s. On average, 1 percent of hospitals convert each year. Many states experienced hospital conversions, but much of the conversion activity was concentrated in California, Florida, Georgia, and Texas. While conversions of not-for-profit hospitals to for-profit status have received significant attention, conversions of public hospitals and for-profit hospitals raise complex policy issues, as well.

Bed Occupancy↗
PubMedDate not supplied

Uncompensated care and hospital conversions in Florida.

Hospital conversions to for-profit ownership have prompted concern about continuing access to care for the poor or uninsured. This DataWatch presents an analysis of the rate of uncompensated care provided by Florida hospitals before and after converting to for-profit ownership. Uncompensated care declined greatly in the converting public hospitals, which had a significant commitment to uncompensated care before conversion. Among converting nonprofit hospitals, uncompensated care levels were low before conversion and did not change following conversion. The study suggests that policymakers should assess the risk entailed in a conversion by considering the hospital's historic mission and its current role in the community.

Florida↗