Evaluation of a non-invasive respiratory monitoring system for sleeping subjects.

In a previous paper we introduced a non-invasive respiratory monitoring system (NIRMS) for monitoring respiratory movements during sleep. Unlike standard sleep laboratory methods, the NIRMS can be used in frail older adults to describe breathing patterns during sleep that will mark individuals with declining neurological function. The present study evaluates the use of the NIRMS as a respiratory monitor and identifies variables that can reliably detect changes in breathing patterns and the presence of other body movements. Data were obtained from eleven healthy adults (six women, five men) whose body mass indices ranged from 20 to 47 kg m(-2), and whose baseline respiratory rates ranged from 4 to 19 breaths per minute. We evaluated three variables derived from frequency and amplitude measurements of the NIRMS: (1) the interval between breathing cycles (the interbreath interval or IBI); (2) the period between breathing cycles (the interbreath frequency or IBF); and (3) the amplitude of breath cycles (AMP). The frequency of NIRMS waveform deflections correlated highly with the frequency of visually observed chest movements (r = 0.99). Compared with a subject's baseline, a standard deviation of IBI > 3.0 s consistently identified time segments with three or more apnoeic events. The IBF and AMP differentiated respiratory from other body movements. An IBF > 20 cycles/s or an AMP > 0.4 V identified experimentally introduced body movements much more accurately than wrist accelerometry (NIRMS detected 99% of events, kappa = 0.90; WA detected 50%, kappa = 0.70). These findings support the use of the NIRMS in monitoring changes in breathing patterns during sleep, especially in frail and cognitively impaired subjects.

Quality of life and productivity in nurses reporting migraine.

A random sample survey was conducted to determine the prevalence of migraine in nurses and to study its effect on quality of life and productivity. Of the 10,000 nurses sampled, 2949 returned the questionnaire for a response rate of 29.5% The majority (99%) of respondents were employed and worked in hospitals (60%). According to the International Headache Society (IHS) criteria, 17% of the sample (n=495) were classified as having migraine. An additional 25% (n = 750) suffered severe headaches but did not meet IHS criteria for migraine, and the remaining 58% (n = 1704) were classified as not having either migraine or severe headaches. The migraineurs had significantly reduced work productivity and quality of life compared to both the severe headache and the nonmigraine nonsevere headache groups. This study will increase awareness and sensitivity of the profession to its colleagues who are migraine sufferers.

The NEECHAM Confusion Scale: construction, validation, and clinical testing.

This article reports the development of the NEECHAM Confusion Scale for rapid and unobtrusive assessment and monitoring of acute confusion. The scale was tested in two samples (N = 168 and 258, respectively) of elderly patients hospitalized for acute medical illness. Internal consistency and interrater reliability of the instrument were found to be high. The NEECHAM correlated well with the Mini-Mental State Examination and the sum of DSM-III-R positive items. Factor analyses identified and confirmed cognitive/behavioral and physiological domains. The NEECHAM provides a valid and reliable bedside assessment of acute confusion, particularly at its onset and in patients with "quiet" manifestations.

Postoperative confusion.

Confusion is a terrible feeling, a feeling of being lost in the most basic sense. The markers, maps, cues, and senses used to orient oneself to the immediate environment are not recognizable. This applies to what one sees, hears, and feels. The person searches for something that makes sense, that he or she can anchor thoughts or actions to. Sitting up, getting up, and walking are anchoring responses. Using hands to touch one's own body, fingering objects, and "calling out" reflect a searching for something that is meaningful to the individual. Patients in various clinical settings who have experienced confusion all report common feelings: anxiety, fear of dying or being hurt, pain, falling, floating, suffocating, feelings of being crazy, being chained, or being lost. The severely confused seem only able to share the experience through their behavior; but it is clear that acute confusion is a physiologic and psychological assault on the body and mind, often worsened by nursing and medical interventions. Acute confusion continues to be a misdiagnosed and undertreated problem. Continued clinical inquiry and research into acute confusion and the use of such knowledge in the practice setting can reverse this trend.

The effect of bile salts on the formation and hydrolysis of cholesterol esters by rat liver enzymes.

To determine the effects of different bile salts on the enzymic esterification of cholesterol and the hydrolysis of cholesterol esters rat liver homogenates and rat liver microsomes were incubated with varying amounts of different bile salts. Bile salts inhibited the formation of radioactive cholesterol esters in incubations of either rat liver homogenates or rat liver microsomes containing [14C]cholesterol. Chenodeoxycholate, glycochenodeoxycholate and taurochenodeoxycholate were more potent inhibitors than their comparable cholate analogues. Bile salts stimulated the hydrolysis of cholesterol esters when incubation were carried out with the liver homogenates. The dihydroxy bile salts were again more potent in this regard than the trihydroxylated bile salts. When the effects of bile salts on cholesterol ester hydrolysis were studied in in vitro incubations of hepatic microsomes a biphasic mode of acion was observed. In the absence of Na+ or K+ bile salts stimulated the hydrolysis of cholesterol oleate. However, following the addition of either Na+ or K+ to the microsomal incubations, bile salts caused an inhibition of cholesterol ester hydrolysis. Since cholesterol esterification was also inhibited under these conditions a direct inhibitory effect (not attributable to enhanced hydrolase activity) of the bile salts on the formation of cholesterol esters by the microsomes was established. Furthermore, this inhibition takes place at the transacylation step involving the fatty acyl-CoA ester and the sterol. These results suggest that bile salts can significantly alter the cholesterol-cholesterol ester profile in the liver, and furthermore, that these effects may be influenced by small changes in the intracellular environment in the region where these reactions occur.