Biomedical subjects
Publications and source records attributed to S H Feinsilver.
The ability to accurately assess respiratory function is essential in the management of critically sick patients. Such measurements help in the diagnosis, management, and outcome of the patients. Proper understanding and interpretation of these parameters is of paramount importance. Clinicians should appreciate the benefits and the limitations of these techniques.
Sleep is much more than simply decreased consciousness, and the distinctions among the stages of nonREM and REM sleep are of significance for the polysomnographer because of their implications for physiologic events. The rules for staging sleep are essentially unchanged since their original description in 1968. This article describes this system for sleep staging, some of its weaknesses, and potential new approaches.
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Polysomnographic recordings of 43 children and adults with Prader-Willi syndrome (PWS) were inspected and classified into 5 age groups. The effect of age and body mass index (BMI) on measures of breathing, oxygen saturation, and sleep efficiency were analyzed. Body mass index (BMI) increased significantly between early childhood and preadolescent groups. Subjecting the data to analysis of variance showed an overall significant effect of BMI but no age effect on breathing parameters and oxygen saturation. Increased BMI was associated with decreased oxygen saturation and with higher apnea/hypopnea index. Sleep efficiency index was significantly lower in adults than in young children, preadolescent, and adolescent groups. These findings emphasize the role of obesity in the development of sleep-related breathing abnormalities and nocturnal oxygen desaturation in patients with PWS.
In a sample of multiple sleep latency test naps following nocturnal polysomnograms from a group of 13 patients of varying ages and diagnoses, we compared a computer-derived electroencephalographic (EEG) measure (z-ratio) with standard visual sleep stage scoring. In this clinical population, z-ratio scoring agreed with human scorers approximately 80% of the time when determining sleep versus wake in 30-second epochs. These results show that a single, objectively quantifiable value derived from a single channel of EEG can distinguish between sleep and wakefulness (as defined by Rechtschaffen and Kales) with at least a moderate degree of precision. When refined, the z-ratio method might be of use as the basis for a new sleep scoring system, particularly where an accurate determination of sleep onset is required.
Patients with Prader Willi syndrome (PWS) often complain of daytime hypersomnolence. Because of reported daytime sleepiness and high prevalence of morbid obesity, these patients have been considered at risk for sleep related disordered breathing, but polysomnographic studies have been limited. We evaluated sleep and breathing polysomnographically in 24 PWS patients including 15 adults and 9 children. All adult patients completed MSLT testing on the day following the nocturnal sleep study. Both adult and children groups showed little or no sleep apnea, but REM related oxygen desaturation was quite common, its severity significantly correlated with increased obesity. Sleep patterns in both groups showed abnormal REM sleep cycles with variable REM latency (at times significantly shortened) and fragmented REM sleep with multiple brief REM periods. REM sleep abnormalities were still present in some patients without REM related desaturation. As a group, patients with PWS demonstrated pathological somnolence as measured by MSLT, which correlated with nocturnal sleep efficiency but not with nocturnal REM latency. It is hypothesized that the abnormal sleep findings in PWS reflect an underlying hypothalamic dysfunction characteristic of this syndrome.
Sleep problems in the elderly are extraordinarily common. The authors discuss normal sleep, changes in sleep with normal aging, and sleep disorders in the elderly, focusing on sleep-disordered breathing. In addition, nocturnal myoclonus and rapid-eye movement behavior disorder are reviewed.
Pneumonia is both more prevalent in the elderly and more severe. This article reviews the approach to nonresolving or slowly resolving pneumonia in the elderly. Specific attention will be given to the natural history of commonly occurring pneumonias in this age group, related host defense impairments, unusual infectious causes of slowly resolving pneumonia, and noninfectious mimics of pneumonia.
Evaluation of slowly resolving or nonresolving pneumonia in the elderly must be based on clear evidence that the disease is behaving outside of the expected norms. Several weeks may be required for even a "typical" pneumonia to resolve in the elderly with comorbid illness. In the presence of an underlying host impairment, the patient should be observed for several additional weeks unless clinical clues raise the suspicion of an unusual infection or noninfectious process. If there is no further evidence of improvement over the extended period of observation, further evaluation is indicated, looking for an unusual infection (particularly tuberculosis or fungal disease) or a noninfectious diagnosis (particularly neoplasm). In our experience, fiberoptic bronchoscopy and computerized tomography are extremely useful first steps in the evaluation of nonresolving pneumonias after an appropriate period of observation.
Twelve women in their third trimester of pregnancy and 10 age-matched nonpregnant controls underwent complete polysomnography for one night in the laboratory. Seven of the original women returned for a second study 3-5 months postpartum. During late pregnancy, women showed increased wake after sleep onset (WASO) and a lower sleep efficiency in comparison with the control group. The percentage of rapid eye movement (REM) sleep was significantly decreased and the percentage of stage 1 significantly increased compared to the nonpregnant group. At 3-5 months postpartum, a significant reduction in WASO and increased sleep efficiency were noted. However, only a slight increase was noted in REM sleep during the postpartum period compared to the prepartum period. The most frequent sleep complaints in the pregnant group were restless sleep, low back pain, leg cramps and frightening dreams. In summary, in accordance with their complaints, women in their third trimester demonstrated polysomnographic patterns of sleep maintenance insomnia.
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Several changes in maternal physiology may profoundly alter sleep, especially during late pregnancy. Any condition that causes maternal hypoxemia will be worsened during sleep, particularly in the supine position. Although high circulating levels of progesterone increase respiratory drive during sleep, in at least some women this protective mechanism is insufficient to prevent sleep-disordered breathing and hypoxemia. The true incidence of sleep-disordered breathing during pregnancy remains unknown. Although many women report sleep disturbance during pregnancy, those with severe snoring, observed irregular breathing with sleep, or excessive daytime somnolence should be referred for clinical polysomnography. With few data thus far available, nasal CPAP would appear to be the treatment of choice. Given the possible consequences of sleep apnea for fetal outcome, any significant sleep-disordered breathing is probably an indication for treatment.
We evaluated the conditions of 33 patients who completed an outpatient pulmonary rehabilitation program to determine what types of improvements occurred, and whether these changes were related to the baseline degree of ventilatory impairment, to determine whether rehabilitation was beneficial to patients, regardless of the degree of underlying lung dysfunction. Endurance measurements, including sustained submaximal performance on a cycle ergometer and the 12-minute walk distance (1,349 +/- 625 feet to 1,700 +/- 670 feet) increased significantly (p less than 0.01), as did multiple educational and subjective parameters. Maximal exercise performance on a graded cycle test improved very little, with a decline in the ventilatory equivalent for oxygen consumption (VE/VO2) being the only significant change (48.2 +/- 28.3 L/ml to 36.6 +/- 8.7 L/ml). Of the observed changes, only one endurance measurement, the sustained submaximal exercise performance, correlated with FEV1 (r = 0.5, p less than 0.01), but only if it was expressed as an absolute number (liters) and not as percent predicted. Lung function did not correlate with changes in the 12-minute walk distance, in maximal exercise performance on the cycle ergometer or with changes in educational and subjective parameters. We conclude that because the magnitude of change in both physiologic and psychologic parameters was not directly related to lung function, the benefits of rehabilitation can extend to all patients with chronic lung disease, regardless of the severity of preexisting pulmonary dysfunction.
This article focuses on the features of common lower respiratory-tract infections in the elderly, specifically those age-associated physiologic and immunologic changes that alter the classic clinical picture of infection. Attention is directed at the epidemiology and clinical features of pneumonia in community, institutionalized, and hospitalized individuals. Those treatment factors unique to an elderly patient are discussed.
Although fiberoptic bronchoscopy (FOB) has been traditionally used to evaluate nonresolving pneumonia, its efficacy is unknown. We, therefore, reviewed FOB in 35 consecutive patients who had (1) a roentgenographic infiltrate, (2) cough, (3) either temperature greater than 38.1 degrees C, leukocytosis, sputum production, (4) symptoms present for at least ten days, and antibiotic therapy for at least one week. Known lung cancer and AIDS were excluded. Fiberoptic bronchoscopy was diagnostic in 86 percent (12/14) in whom a specific cause was found. No patient had endobronchial cancer. Two patients with nondiagnostic FOB and persistent systemic symptoms had open lung biopsy specimens showing Wegener's granulomatosis and bronchiolitis obliterans with organizing pneumonia (BOOP). Twenty-one patients with nondiagnostic FOB had no final diagnoses other than community-acquired pneumonia. We conclude that FOB is extremely useful in finding a specific diagnosis for a nonresolving pneumonia when a specific diagnosis can be made. Fiberoptic bronchoscopy was most likely to yield a specific diagnosis in nonsmoking patients with multilobar infiltrates of long duration and could have been avoided in older, smoking, or otherwise compromised patients with lobar or segmental infiltrates with no decrease in diagnostic yield in our series.
We report a patient who developed adult respiratory distress syndrome following relief of pericardial tamponade. Because of increasing recognition of pulmonary edema in this situation, we recommend gradual removal of pericardial fluid with hemodynamic monitoring to limit the massive fluid shifts which appear to herald this dire complication.