Differences In Discharge Patterns Research Articles

Abstract TP80: Differences in Access to Post Acute Care Services Between Traditional Medicare and Medicare Advantage Beneficiaries in Michigan

Introduction: In recent years, Medicare Advantage (MA) enrollment in the US has increased dramatically relative to traditional Medicare (TM). There is evidence to suggest that MA stroke patients are less likely to receive inpatient rehabilitation facility (IRF) based care in favor of home health. To evaluate potential gaps in quality of care, we compared post-acute care use patterns following hospitalization for acute stroke between TM and MA populations. Methods: We probabilistically linked data from Michigan’s Get With The Guidelines-Stroke registry and Michigan Value Collaborative multipayer claims data registry for 16,231 TM and MA beneficiaries discharged alive following acute stroke (ICD-10 I61-I63) between 2016-2020. We used discharge claims to identify the initial discharge destination classified as home, home health, IRF, skilled nursing facility (SNF) or other. Unadjusted differences in proportions and time trends between TM and MA populations were assessed using chi square statistical tests. Results: TM and MA-insured patients constituted 75.1% and 24.9% of the 16,231 stroke discharges, respectively. Compared with TM, MA beneficiaries were older (77.4 vs 75.8, P <0.001), less likely to be female (50.3% vs 55.3%, P <0.001), and more likely to be white (87.0% vs 82.4%, P <0.001). Over the study period, the proportion of MA patients increased from 21.2% in 2016 to 32.4% in 2020 ( P <0.001) (Table). Overall, significant differences in discharge destination were due to more MA patients discharged to home and home health ( P <0.001). Despite significant differences between MA and TM populations, there were no consistent time trends in discharge patterns. However, the exception was in 2020 where increased utilization of home health was accompanied by decreases in IRF and SNF discharge. Conclusions: We did not find clinically meaningful differences in discharge patterns between TM and MA populations. Changes in 2020 were likely attributed to COVID-19.

Significance of the electrophysiological border between hypothalamic hamartomas and the hypothalamus for the target of ablation surgery identified by intraoperative semimicrorecording.

Ablation surgery has become the first line of treatment for hypothalamic hamartomas (HHs). For effective treatment, optimum targeting of ablation is mandatory. The present study aimed to evaluate the correspondence between the electrophysiological features of HHs and morphological targeting by semimicrorecording during stereotactic radiofrequency thermocoagulation (SRT). Eighty HH patients who underwent SRT were involved. Semimicrorecording was performed on the first trajectory. The distance from the center of the target at the morphological border (TMB) determined by magnetic resonance imaging, differences in discharge patterns, and area potentials (APs) were measured. The electrophysiological border (EB) between the HH and hypothalamus was detected by semimicrorecording in 73 (91.3%), AP increase (API) in the HH was detected in 31 (38.8%), and spike discharges (SDs) of the HH were detected in 56 patients (70.0%). Semimicrorecording showed significantly different APs among structures passing through the trajectory, except between API and SDs. The median distances from the center of the TMB to the EB, API, SDs, and AP decline were -3.50, -2.49, -1.38, and +2.00mm, respectively. The electrophysiological features of HHs were shown by semimicrorecording during SRT. The EB corresponded to the morphological border. The electrophysiologically active area of HHs was located near the border. Ablation surgery should focus on disconnection at the border between the HH and the hypothalamus to maximize its effectiveness, as well as to reduce complications.

Fluvial response to an historic lowstand of the Great Salt Lake, Utah

ABSTRACTUnderstanding fluvial adjustments to base level changes benefits the fields of sequence stratigraphy, geomorphology and petroleum geology. This investigation is a modern case study of the channel dynamics of Lee Creek and the Goggin Drain, two streams that are part of the Jordan River drainage into the endorheic Great Salt Lake of northern Utah, a lacustrine system that has experienced multiple, decadal‐scale base level changes. Since 1965, the lake level has fluctuated in elevation more than 6 m, transitioning from an historic lowstand [< 1279 m above sea level (a.s.l.)] to an historic highstand (>1284 m a.s.l.), and in 2009–2010 approaching an historic lowstand. This study uses detailed aerial images, fieldwork and LiDAR data to link the modern geomorphology and channel hydraulics to specific variations in sediment transport, channel form, and avulsion behavior. Although Lee Creek and the Goggin Drain are situated only a few kilometers apart and share similar shore zone gradients, substrates and vegetation patterns, and have been subjected to the same changes in lake level, their channel forms have evolved very differently. Differences in discharge patterns are likely the most influential factor causing the meandering form of Lee Creek and the braiding channel of the Goggin Drain. Despite the differences in discharge, total sediment eroded from the two streams is comparable and can be attributed to similar stream power/unit stream width in the two streams. Although Lee Creek has not recently been avulsive, three major avulsions of the Goggin Drain have taken place since 1965. Two possible styles of avulsion are interpreted: an allogenic response to changing base level, and an autogenic response dictated by channel morphology and hydraulics. Despite a wealth of available information, avulsions cannot be unequivocally attributed to one style or another. Caution should be used when attempting to link the complex process of avulsion to causal mechanisms. Copyright © 2011 John Wiley & Sons, Ltd.

Representation of the spectral dominance region of pitch in the steady-state temporal discharge patterns of cochlear nucleus units

Single-unit responses to infinitely iterated rippled noise and wideband noise were recorded from the cochlear nucleus of anesthetized chinchillas. Rippled noises had a fixed delay of 4 ms, and spectral depth was varied by attenuating the delayed version of the noise. Temporal discharge patterns were analyzed using neural autocorrelograms, and responses to rippled noises were compared to wideband noise responses. Chopper units with best frequencies in the range of the first to second harmonics of the rippled noise showed large differences in discharge patterns between rippled noise and wideband noise responses, but chopper units with best frequencies centered at higher harmonics did not show large differences. Consequently, the Chopper group of units showed no evidence of a neural representation of the dominance region. Primarylike units did show a neural representation of dominance that is related to behavioral performance. For Primarylike units with best frequencies around the third to fifth harmonics of the rippled noise, large differences in discharge patterns between rippled noise and wideband noise responses were observed. The results suggest that bushy cells play an important role in processing pitch-related information and should be included as important elements in neural models of periodicity processing.

Sexually dimorphic micturition in rats: relationship of perineal muscle activity to voiding pattern

In the present study we examined the possibility that striated muscle activity may underlie sexually dimorphic micturition in rats. Micturition dynamics, the gross anatomy of the external urethral sphincter, and the participation of the striated perineal muscles in micturition were compared in urethane-anesthetized adult male and female rats. Bladder contraction characteristics, particularly the magnitude of bladder high-frequency pressure waves during voiding, differed between sexes. Dissections indicated that the sphincter was more extensive and thicker in males than in females. Electromyography showed that in both sexes the sphincter discharged in bursts that correlated with the rising phase of high-frequency bladder pressure oscillations. Regional differences in discharge pattern were seen in the sphincters of males, with the proximal part of the sphincter showing components activated during bladder filling. Bulbospongiosus, ischiocavernosus, and cremaster muscles also were activated during bladder contraction in males. In both sexes transection of the motor branch of the lumbosacral plexus eliminated the bladder high-frequency oscillations and reduced voided volume. Neurectomy did not affect bladder pressure but reduced voiding efficiency by 45% in males. In females the bladder pressure was dramatically decreased, but voiding efficiency only decreased by 24%. Our findings suggest that, in rats, striated perineal muscles contribute to the sexually dimorphic micturition. Activity of the dimorphic perineal muscles may regulate genital and urinary urethra expulsive functions, helping to expel seminal plug and fluids through the long urethra in the male.

Are alpine lake outlets less harsh than other alpine streams?

We investigated the intra-annual chemical and physical properties of 16 lotic systems situated in the Swiss Alps that comprised alpine lake outlets and streams of kryal and rhithral origin. A primary goal of the study was to examine whether alpine lake outlets are less harsh lotic habitats than alpine non-outlet streams, as expected from studies of lowland lake outlets. The presence of a glacier and associated seasonality in glacial melt were primary determinants of environmental conditions in alpine lotic systems through the influence on flow regime, water temperature, and seasonal changes in chemical variables. Lake outlets exhibited higher maximum water temperatures and lower daily temperature fluctuations compared to non-outlet streams. Channel stability of the lotic systems was analyzed using estimates of shear stress, the Pfankuch score (PSI) and a multivariate habitat index (MHI). Indices using shear stress characterized channels with stream slopes ≥15 % as least stable and lake outlets with slopes ≤4 % as most stable. PSI and MHI mainly separated rhithral sites as stable and kryal sites as unstable, resulting from differences in discharge patterns. None of the indices resulted in distinct differentiation between the habitat stability of lake outlets and respective streams. Assessment of these indices suggested that it is necessary to incorporate both spatial and temporal changes in habitat parameters to provide a valid measure of the stability of a particular alpine stream type. Our results indicated that the habitat characteristics of alpine lotic systems are mainly controlled by the presence of a glacier and its seasonality, and on a lower hierarchical level by the presence of an upstream lake.

Hydrology and substrates: determinants of oligochaete distribution in lowland streams (The Netherlands)

In most soft-bottomed, lowland streams in the Netherlands discharge regimes largely follow the precipitation pattern. Winter discharges are higher and much more dynamic then summer discharges, although rain storms throughout the year cause unexpected peak flows. Minimal precipitation, reduced stream flow and droughts can occur during the summer months. Lowland stream habitat, particularly in The Netherlands, is hydrologically dynamic, with substrates frequently moved or disturbed. Differences in discharge patterns in Dutch soft-bottomed lowland streams are expected to affect distribution patterns of macroinvertebrates and thus oligochaetes. Ten small to medium sized lowland streams, differing from one another in hydrological regime, were studied. Five major habitats in each stream were assessed on three occasions over a 15-month period. Each habitat sampled with a micro-macrofauna shovel; during each sampling period, several environmental parameters, especially hydrological and substrate parameters, were measured. Ordination (CANOCO) (Ter Braak, 1989) and statistical tests (chi-squared test) (Lindgren & McElrath, 1970) were used to determine the major oligochaete distribution patterns between streams as well as between habitats within each stream. Each stream was characterized by its oligochaete assemblage; general distribution patterns and individual oligochaete–substratum relationships were documented. Hydro-morphological parameters together explained the differences in major distribution patterns. Preferences of oligochaetes for specific structural habitats are discussed.

Noise components in Limulus vision.

three), as well as processes in the lamina and medulla (n = 10, Fig. 1 B). Previous anatomical studies witb cobalt chloride showed that a single nerve fiber gives off a puff of processes in the lamina as it continues on into the medulla and other optic nuclei (10). What is the cellular compartment we are recording from? The spike discharge and Neurobiotin staining patterns strongly suggest the axons of optic nerve fibers. However, such large slow potentials would not be expected in this compartment because the soma is located 4-5 cm away in the retina. Moreover, it is unclear why the spike size would change, spike duration would differ, and multiple axons would stain if this were the case. Hence, it appears that we are recording from synaptic compartments, presumably in the branches of optic nerve fibers, that receive action potentials from the main axon and slow potentials from other nerve fibers or cells in the brain. The differences in discharge patterns to single ommatidial and whole eye stimulation result from lateral inhibition in the retina, whereas the differences in slow potentials are a consequence of synaptic interactions in the lamina. Neural processing in the lateral eye of the horseshoe crab is hidden from microelectrodes in the tangled web of the lateral plexus that interconnects neighboring ommatidia to mediate lateral inhibition. Neural processing in the lamina appears to use the same integrative mechanisms as the retina and may be more accessible to electrode studies. If so, we may gain an understanding of the synaptic interactions that occur across a parallel array of optic nerve fibers and their influence on the information sent to other regions of the brain. Supported by NSF grant BNS9309539 and NIH grants MH4974 1 and EY00667.

The Relation Between Hospital Experience and Mortality for Patients With AIDS

To determine whether there is an association between mortality and hospital acquired immune deficiency syndrome (AIDS) experience for all AIDS-related diagnoses, and to determine whether the association is explained by differences in severity of illness, earlier discharge of terminally ill patients, or differences in resource use. Population-based statewide cohort study. All hospitalizations identified for a cohort of AIDS patients diagnosed during 1987 in 40 Massachusetts hospitals were included. All women and all male intravenous drug users (n = 151), and a random sample of all male non-intravenous drug users diagnosed with AIDS during 1987 in Massachusetts (n = 149). Primary end points studied were (1) inpatient mortality and (2) 30-day mortality. Length of stay, cost, and intensive care unit use were also examined. In 806 hospitalizations at 40 hospitals inpatient mortality was 13.2%. Relative risk of mortality at low AIDS experience hospitals was 2.16 (95% confidence interval, 1.43 to 3.26) compared with high AIDS experience hospitals. When logistic regression was used to control for age, sex, race, human immunodeficiency virus transmission mode, severity, payer, admission type, hospital ownership, and teaching status, low hospital experience with AIDS remained a significant predictor of inpatient mortality (relative risk, 2.92; 95% confidence interval, 1.37 to 6.22). Comparisons of 30-day mortality by hospital AIDS experience yielded similar results. Length of stay and intensive care unit use were also significantly higher at low-experience hospitals after controlling for severity of illness (P < .05). We conclude that mortality of AIDS patients is higher at hospitals with less AIDS experience. This finding is not because of greater severity of illness, differences in discharge patterns of the terminally ill, or less intensive use of resources.

The relation between hospital experience and mortality for patients with AIDS

<h3>Objective.</h3> —To determine whether there is an association between mortality and hospital acquired immune deficiency syndrome (AIDS) experience for all AIDS-related diagnoses, and to determine whether the association is explained by differences in severity of illness, earlier discharge of terminally ill patients, or differences in resource use. <h3>Design and Setting.</h3> —Population-based statewide cohort study. All hospitalizations identified for a cohort of AIDS patients diagnosed during 1987 in 40 Massachusetts hospitals were included. <h3>Patients.</h3> —All women and all male intravenous drug users (n=151), and a random sample of all male non—intravenous drug users diagnosed with AIDS during 1987 in Massachusetts (n=149). <h3>Main Outcome Measures.</h3> —Primary end points studied were (1) inpatient mortality and (2) 30-day mortality. Length of stay, cost, and intensive care unit use were also examined. <h3>Results.</h3> —In 806 hospitalizations at 40 hospitals inpatient mortality was 13.2%. Relative risk of mortality at low AIDS experience hospitals was 2.16 (95% confidence interval, 1.43 to 3.26) compared with high AIDS experience hospitals. When logistic regression was used to control for age, sex, race, human immunodeficiency virus transmission mode, severity, payer, admission type, hospital ownership, and teaching status, low hospital experience with AIDS remained a significant predictor of inpatient mortality (relative risk, 2.92; 95% confidence interval, 1.37 to 6.22). Comparisons of 30-day mortality by hospital AIDS experience yielded similar results. Length of stay and intensive care unit use were also significantly higher at low-experience hospitals after controlling for severity of illness (<i>P</i>&lt;.05). <h3>Conclusions.</h3> —We conclude that mortality of AIDS patients is higher at hospitals with less AIDS experience. This finding is not because of greater severity of illness, differences in discharge patterns of the terminally ill, or less intensive use of resources. (<i>JAMA</i>. 1992;268:2655-2661)

Disturbances in Voluntary Recruitment Order of Low and High Frequency Motor Units on Blockades of Proprioceptive Afferent Activity

The voluntary recruitment order of anterior tibial motor units was studied in electromyographic recordings using both low and high impedance electrodes. It was shown in previous papers, that the recruitment order in sustained voluntary contraction is normally stable and that motor units with low thresholds discharge at low, regular frequencies and that motor units with high thresholds discharge at higher and more irregular frequencies. In this paper the consequences for the discharge properties of reduced afferent inflow in sustained voluntary contraction were studied, using partial ischemic or lidocain blockades of the muscle nerve and local cooling of the muscle belly. 1. The recruitment order of certain low and certain high frequency units was reversed. 2. The muscle tension and sense of effort necessary for tonic firing were increased for certain low frequency units but decreased for certain high frequency units. 3. On severe reduction of the afferent inflow, the differences in discharge pattern between low and high frequency units were decreased. It is concluded that the recruitment of low frequency units before high frequency units in sustained voluntary contraction is partly due to proprioceptive afferent activity favouring low frequency units and disfavouring high frequency units. It is also concluded that the afferent inflow is involved in restricting certain units to low frequency discharge and others to high frequency discharge.

Intrapulmonary CO 2 receptors in the duck:III. Functional localization

Single-unit activity in the right vagus nerve was recorded from 67 intrapulmonary CO 2 receptors in anesthetized ducks. The right caudal thoracic air sac was cannulated and the mesobronchus was blocked in the right lung between the origins of ventrobronchi and dorsobronchi. The lung could be unidirectionally ventilated in either direction. Two different tests were applied to each receptor in an attempt to determine its location within the lung. 1. (1) Gross localization of receptors in cranial or caudal parts of the lung was assessed on the basis of differences in discharge frequency when gas flow direction was air sac to trachea vs. trachea to air sac. More than 95% of the receptors were in caudal parts of the lung. 2. (2) For finer localization, pure CO 2 or O 2 was insufflated via catheters into the ventilatory gas stream either proximal or distal to the blocking balloon during gas flow in both directions. In this way, the location of 60 receptors (90%) could further be specified. Of these receptors 56% were found to be in the caudal ends of paleopulmonic parabronchi, 27% in neopulmonic parabronchi, and 12% in dorsobronchi or in parabronchial tissue near the dorsobronchi; only 5% were located in the cranial ends of paleopulmonic parabronchi; none were in the ventrobronchi or extrapulmonary air ways. Thus, CO 2 receptors are located in those parts of the lung that experience marked fluctuations in CO 2 concentration during the respiratory cycle. Differences in location permit satisfactory explanation of differences in discharge pattern of CO 2 receptors observed during spontaneous breathing.

Intrapulmonary CO 2 receptors in the duck: II. Comparison with mechanoreceptors

Single-unit recordings from vagal afferents exhibiting discharge patterns in phase with pump ventilation were made in domestic ducks to determine if receptors, other than intrapulmonary CO 2 receptors, discharge in phase with the pump. After identification of the units during pump ventilation, the units were tested during unidirectional ventilation for their response to changes in inspired CO 2 concentration (F i CO 2 ) and to changes in mechanical distortion resulting from increases in intrapulmonary pressure (Pip). Two types of receptors with distinct differences in discharge pattern were encountered: (1) Receptors which responded rapidly to changes in F I CO 2 but which were insensitive to mechanical deformation (18 receptors out of 22). These receptors were located in the lung and were similar to those described by Fedde et al. (1974). (2) Receptors that were insensitive to changes in F I CO 2 but increased their discharge frequency parallel to increases in Pip (4 receptors out of 22). These receptors appear to be slowly adapting mechanoreceptors. Their location could not be determined. The results suggest that with cyclic ventilation, spontaneous or artificial, only two types of receptors with vagal afferents are stimulated, both of which are highly stimulus-specific. Whereas the intrapulmonary CO 2 receptors are very likely to be involved in control of breathing, the role played by mechano-receptors is unknown.