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Biomedical subjects

W Mendelson

Publications and source records attributed to W Mendelson.

At least 19 recordsLinked to original sources
PubMed2001

The relationship of sedation to deliberate self-extubation.

STUDY OBJECTIVES: To evaluate the relationship between sedative therapy and self-extubation in a large medical-surgical intensive care unit (ICU). DESIGN: Retrospective, case-controlled study. SETTING: Large teaching hospital. PATIENTS: All adult patients who underwent unplanned self-extubation during a 12-month period (n = 50). Each patient was matched to two control patients who did not self-extubate based on age, gender, dates in hospital and diagnosis. INTERVENTIONS: none. MEASUREMENTS: Data collected included time to self extubation, dosages and types of benzodiazepines, opioid analgesics, antipsychotics, and hypnotics. Data on the degree of agitation as assessed by nursing staff also were obtained. MAIN RESULTS: When compared to controls, patients in the self-extubation group were more likely to have received benzodiazepines (59% vs. 35%; p < 0.05), but equally likely to have received opioids and/or paralytic drugs. Patients who self-extubated were twice as likely as controls to be agitated (54% vs. 22%; p < 0.05). Use of benzodiazepines was more common in agitated patients than in nonagitated patients (62% vs. 35%; p < 0.02). Among nonagitated patients who self-extubated, increased use of benzodiazepines (57% vs. 29%; p < 0.05) was noted when compared to nonagitated controls. CONCLUSIONS: In intubated ICU patients, benzodiazepines may not consistently treat agitation effectively or prevent self-extubation. Such an effect may be due to paradoxical excitation, disorientation during long-term administration, or differences in drug administration between ICU and operating room (OR) environments.

Aged↗
PubMed1997

Characteristics and outcomes of patients who self-extubate from ventilatory support: a case-control study.

OBJECTIVE: To identify factors associated with the occurrence of deliberate self-extubation and to describe associated patient outcomes. DESIGN: Case-control study. SETTING: ICUs of a national referral, tertiary medical center. PARTICIPANTS: Fifty adult, intubated patients who had self-extubated from mechanical ventilatory support. Two control subjects who had not self-extubated were matched to each case based on age, gender, primary discharge diagnosis, and time hospitalized (within same quarter). MEASUREMENTS: Standardized coding of medical record information, including demographic characteristics, clinical information, intubation and mechanical ventilation characteristics, medications, and selected laboratory indexes. RESULTS: As compared to the control subjects, patients who self-extubated were more likely to be medical than surgical patients (p<0.001) and have a current history of smoking (p<0.05). Prior to the self-extubation, patients had a greater likelihood of hospital-acquired infections (p<0.001) or other hospital-acquired adverse events (p<0.001), abnormal (<10, >50 mg/dL) BUN (p<0.05), and abnormal (<20, >50 mm Hg) PaCO2 (p<0.05); they also were more likely to be restless or agitated (p<0.001), and more likely to be physically restrained (p<0.001). A logistic regression model demonstrated that presence of restlessness or agitation and presence of a hospital-acquired adverse event were independently associated with self-extubation from mechanical ventilatory support. In examining outcomes, as compared to the control subjects, those who self-extubated had longer lengths of stay in ICU and hospital, were more likely to need reintubation, and were more likely to suffer complications from intubation. However, none of the cases died within 48 h of self-extubation. CONCLUSION: The results underscore the need for clinical guidelines for weaning and for monitoring patients at risk of self-extubation.

Adult↗
PubMed1997

Effect of beta-carboline-3-carboxoylate-t-butyl ester on ventilatory control.

beta-carboline-3-carboxylate-t-butyl ester (beta CCT) is the most selective antagonist for the alpha 1 beta 2 gamma 2 benzodiazepine (BZ) receptor subtype which blocks anticonvulsant and antipunishment (anxiolytic) but not sedative and myorelaxant effects of diazepam. We sought to determine whether the alpha 1 beta 2 gamma 2 BZ receptor subtype modulates ventilation and whether beta CCT antagonizes respiratory depressant effects of BZ's. Room air (RA) ventilation and the ventilatory response to 6% & 12% CO2 were non-invasively assessed by barometric plethysmography in 30 gm mice, n = 11. Plethysmograph signal amplitude (AMP), respiratory rate (RR) and minute ventilatory effort (MVE = AMP*RR), were measured. Runs were performed pre-drug & after IP injection of saline, vehicle for beta CCT, beta CCT (60mg/kg), midazolam (10mg/kg), and midazolam followed by beta CCT. Compared with pre-drug value, midazolam depressed MVE during RA and CO2 stimulation (% of pre-drug value: RA:57.7 +/- 17.4%, 6% CO2:53.73 +/- 14.3%, 12% CO2:69.1 +/- 26.1%, p < .0001, ANOVA). Subsequent beta CCT partially reversed this depression during RA conditions (72.8 +/- 25.7% of pre-drug value, p < .03 compared with midazolam) and 6% CO2 stimulation (67.1 +/- 10.7% of pre-drug value, p < .006 compared with midazolam) but not with 12% CO2. Thus, the alpha 1 beta 2 gamma 2 BZ receptor subtype modulates ventilation and beta CCT partially antagonizes respiratory depressant effects of BZ's.

Animals↗
PubMed1997

Positive correlations between cerebral protein synthesis rates and deep sleep in Macaca mulatta.

Local rates of cerebral protein synthesis (ICPSleu) were determined with the autoradiographic L-[1-14C]leucine method in seven awake and seven asleep, adult rhesus monkeys conditioned to sleep in a restraining chair in a darkened, ventilated chamber while EEG, EOG, and EMG were monitored. Prior to the period of measurement all animals slept for 1-4 h. Controls were awakened after at least one period of rapid-eye-movement (REM) sleep. Experimental animals were allowed to remain asleep, and they exhibited non-REM sleep for 71-99% of the experimental period. Statistically significant differences in ICPSleu between control and experimental animals were found in four of the 57 regions of brain examined, but these effects may have occurred by chance. In the sleeping animals, however, correlations between ICPSleu and percent time in deep sleep were positive in all regions and were statistically significant (P < or = 0.05) in 35 of the regions. When time in deep sleep was weighted for the integrated specific activity of leucine in grey matter, positive correlations were statistically significant (P < or = 0.05) in 18 regions in the experimental animals. These results suggest that rates of protein synthesis are increased in many regions of the brain during deep sleep compared with light sleep.

Animals↗
PubMed1989

Measuring cholinergic sensitivity: I. Arecoline effects in bipolar patients.

In a previous study, bipolar patients were found to be more sensitive than controls to induction of rapid eye movement (REM) sleep by the direct muscarinic agonist arecoline. We have replicated this observation in a new group of patients and controls. However, much overlap between groups was seen. Muscarinic supersensitivity appears to be present in some bipolar affective patients, but the REM induction procedure may not be the optimal method for measuring it.

Adult↗
PubMed1988

The use of triazolam in phase-advanced sleep.

The need for optimal nocturnal performance continues to increase in our society. Nighttime function is dependent upon the ability to sleep effectively during the day. The current study examined daytime sleep after placebo, 0.125 mg (364 nmol), 0.25 mg (729 nmol), or 0.50 mg (1458 nmol) of triazolam, and nocturnal performance in the work shift that followed. Forty-one normal young adult subjects participated in a repeated-measures design in which each subject received each medication dose level in a separate week. The results indicated that day sleep increased as a linear function of drug dose from 234 to 374 minutes. Nocturnal alertness, as measured by subjective report and objective nap latency test, increased significantly following the use of triazolam, 0.25 and 0.50 mg, for the day sleep period. Nocturnal performance, as measured by auditory vigilance and additions, also increased significantly following the use of triazolam. Marginal evidence for medication hangover was found at the 0.50-mg dose, and it was therefore recommended that the use of the 0.50-mg dose be monitored carefully if performance demand were to follow medication use by less than 12 hours. The results for the study were interpreted as indicating that under certain conditions, triazolam could effectively increase daytime sleep and improve alertness and performance in the following nocturnal work period.

Adult↗
PubMed1984

Growth hormone neurosecretory dysfunction. A treatable cause of short stature.

Pulsatile growth hormone (GH) secretion was assessed in a subgroup of short children to determine whether they had GH secretory abnormalities, and these results were compared with those of normal and GH-deficient children. This subgroup of children was defined as having GH neurosecretory dysfunction and met the following criteria: height, less than first percentile; growth velocity, 4 cm/yr or less; bone age, two or more years behind chronological age, normal findings from provocative GH tests (peak, greater than or equal to 10 ng/mL), low somatomedin-C level, and abnormal 24-hour GH secretory patterns. When compared with controls, both children with GH neurosecretory dysfunction and GH-deficient patients had a significant decrease in parameters relating to the total GH secretion during the 24-hour period. As with GH-deficient children, the group with GH neurosecretory dysfunction more than doubled their growth velocity after replacement therapy with exogenous human GH during the first year of treatment. As a result of these detailed studies on pulsatile GH secretion, we suggest that there is a spectrum of GH secretory abnormalities from absolute deficiency to an intermittent irregularity in GH secretion.

Adolescent↗
PubMed1983

Hypnogenic center theory of sleep: no support from metabolic mapping in monkeys.

By comparing rates of glucose utilization in brains of monkeys in non-REM sleep and two types of awake controls, we attempted to reveal cerebral hypnogenic centers that drive organisms to sleep through increases in their neural activity. Instead we found that metabolic activity is reduced in all the putative hypnogenic centers during sleep as compared to wakefulness. The results thus offer no support for the notion of an active center that either maintains or triggers sleep.

Animals↗
PubMed1981

Childhood obsessive-compulsive disorder.

The authors collected clinical diagnostic, neurophysiological, electrophysiological, and biochemical data on 9 adolescents who had primary obsessive-compulsive disorder. The results indicate considerable descriptive validity of the syndrome in childhood and its independence from obsessional traits; however, all of the children had a history of major depressive disorder, and their sleep EEG measures resembled those of young adults with primary depressive disorder. The patients' families did not have a more consistent pattern of anxiety disorder or any other psychiatric disorder than do families of adult obsessive patients. Psycholinguistic test results showed a lack of normal laterality, which has been reported for other psychiatric illness.

Adolescent↗
PubMed1980

Childhood enuresis. I. Sleep patterns and psychopathology.

Forty severely enuretic boys (mean age, 10.8 years) were selected; 20 had associated psychiatric disturbance and 20 had enuresis as an isolated symptom. Psychiatrically disturbed enuretics had both slightly higher scores on a neurological examination for "soft signs" and more "stressful" background events. Enuretic events were not associated with a particular sleep stage; disturbed and nondisturbed enuretics did not differ from each other with respect to the distribution of enuretic events by sleep stage. The results do not support the concepts of enuresis as an arousal disorder or of there being different sleep profiles of enuresis in relation to behavioral pathology.

Adolescent↗
PubMed1980

Childhood enuresis. II. Psychopathology, tricyclic concentration in plasma, and antienuretic effect.

The efficacy of treatment with imipramine hydrochloride, desipramine hydrochloride, methscopolamine bromide, and placebo was compared in a study with 40 severely enuretic boys. Both tricyclic antidepressants were superior to placebo and methscopolamine, but they did not differ from each other. Psychiatric disturbance, sleep measures, and other clinical parameters did not predict antienuretic response to tricyclics nor was there a psychotropic response. Plasma concentrations of imipramine and desipramine showed a significant correlation with clinical effect. However, true nonresponders were found, and tolerance to the antienuretic drugs developed in some boys.

Child↗