Papers by Zachary Grinspan
Pediatric Emergency Care, 2016
Hyponatremia is a well-known sequela of community-acquired pneumonia (CAP). B-type natriuretic pe... more Hyponatremia is a well-known sequela of community-acquired pneumonia (CAP). B-type natriuretic peptide (BNP) has a natriuretic effect and was found to be elevated in patients with CAP. We investigated whether BNP has a role in the pathophysiology of hyponatremia in pediatric CAP. Serum and urine electrolytes and osmolality, as well as NT-pro-BNP (N-BNP), were obtained in 49 hospitalized pediatric patients with CAP (29 with hyponatremia, 20 with normal sodium levels. Urine sodium levels were lower in the hyponatremic group compared with the normonatremic group (24.3 meq/L vs 66.7 meq/L, P = 0.006). No difference in N-BNP levels was found between groups (median, 103.8 vs 100.1; P = 0.06; interquartile range, 63.7-263.3 pg/mL vs 47.4-146.4 pg/mL). N-BNP was not associated with serum or urinary sodium levels. These results indicate that BNP is unlikely to play a causative role in the mechanism of hyponatremia in CAP.
New England Journal of Medicine
Dr. Laura Chapman (Pediatrics): A 9-year-old boy with autism was admitted to this hospital becaus... more Dr. Laura Chapman (Pediatrics): A 9-year-old boy with autism was admitted to this hospital because of pain in the hip, refusal to walk, and the recent onset of a rash and gingival swelling.
Population Health Management, 2016
Understanding how often patients seek care from multiple hospitals is important for care of indiv... more Understanding how often patients seek care from multiple hospitals is important for care of individuals and populations, but it is not routinely measured because of lack of data. This study used data from a health information exchange (HIE) to measure the frequency with which patients seek care from multiple hospitals. This was a retrospective cohort study (2010-2011) of all patients who sought emergency department (ED) or inpatient care at 6 participating hospitals in Manhattan. The study found that all 6 hospitals shared patients with each of the other hospitals and that 10.0% of all ED visits and 9.1% of all admissions were for patients who had been seen in a different hospital in the past 12 months. Patients are frequently seen by multiple hospitals, which poses a challenge for clinical care and population management. By capturing which patients are seen where and when, HIEs are well suited for facilitating population management.
PloS one, 2016
The Korean National Health Insurance, which provides universal coverage for the entire Korean pop... more The Korean National Health Insurance, which provides universal coverage for the entire Korean population, is now facing financial instability. Frequent emergency department (ED) users may represent a medically vulnerable population who could benefit from interventions that both improve care and lower costs. To understand the nature of frequent ED users in Korea, we analyzed claims data from a population-based national representative sample. We performed both bivariate and multivariable analyses to investigate the association between patient characteristics and frequent ED use (4+ ED visits in a year) using claims data of a 1% random sample of the Korean population, collected in 2009. Among 156,246 total ED users, 4,835 (3.1%) were frequent ED users. These patients accounted for 14% of 209,326 total ED visits and 17.2% of $76,253,784 total medical expenses generated from all ED visits in the 1% data sample. Frequent ED users tended to be older, male, and of lower socio-economic statu...
Applied clinical informatics, 2016
Physicians caring for children with serious acute neurologic disease must process overwhelming am... more Physicians caring for children with serious acute neurologic disease must process overwhelming amounts of physiological and medical information. Strategies to optimize real time display of this information are understudied. Our goal was to engage clinical and engineering experts to develop guiding principles for creating a pediatric neurology intensive care unit (neuroPICU) monitor that integrates and displays data from multiple sources in an intuitive and informative manner. To accomplish this goal, an international group of physicians and engineers communicated regularly for one year. We integrated findings from clinical observations, interviews, a survey, signal processing, and visualization exercises to develop a concept for a neuroPICU display. Key conclusions from our efforts include: (1) A neuroPICU display should support (a) rapid review of retrospective time series (i.e. cardiac, pulmonary, and neurologic physiology data), (b) rapidly modifiable formats for viewing that dat...
Amia Annual Symposium Proceedings Amia Symposium Amia Symposium, 2013
For people with epilepsy, the potential value of health information exchange (HIE) is unknown. We... more For people with epilepsy, the potential value of health information exchange (HIE) is unknown. We reviewed two years of clinical encounters for 8055 people with epilepsy from seven Manhattan hospitals. We created network graphs illustrating crossover among these hospitals for multiple encounter types, and calculated a novel metric of care fragmentation: "encounters at risk for missing clinical data." Given two hospitals, a median of 109 [range 46 - 588] patients with epilepsy had visited both. Due to this crossover, recent, relevant clinical data may be missing at the time of care frequently (44.8% of ED encounters, 34.5% inpatient, 24.9% outpatient, and 23.2% radiology). Though a smaller percentage of outpatient encounters were at risk for missing data than ED encounters, the absolute number of outpatient encounters at risk was three times higher (14,579 vs. 5041). People with epilepsy may benefit from HIE. Future HIE initiatives should prioritize outpatient access.
The Faseb Journal, Mar 1, 2006
Annals of neurology, Jan 24, 2015
Infantile spasms are seizures associated with a severe epileptic encephalopathy presenting in the... more Infantile spasms are seizures associated with a severe epileptic encephalopathy presenting in the first 2 years of life, and optimal treatment continues to be debated. This study evaluates early and sustained response to initial treatments and addresses both clinical remission and electrographic resolution of hypsarhythmia. Secondarily, it assesses whether response to treatment differs by etiology or developmental status. The National Infantile Spasms Consortium established a multi-center, prospective database enrolling infants with new diagnosis of infantile spasms. Children were considered responders if there was clinical remission and resolution of hypsarhythmia that was sustained at three months after first treatment initiation. Standard treatments of ACTH, oral corticosteroids, and vigabatrin were considered individually, and all other non-standard therapies were analyzed collectively. Developmental status and etiology were assessed. We compared response rates by treatment grou...
Amia Annual Symposium Proceedings Amia Symposium Amia Symposium, Nov 16, 2013
Health information exchange (HIE) systems may address the challenges that prevent easy access to ... more Health information exchange (HIE) systems may address the challenges that prevent easy access to patients' existing radiological information at the point of care. However, little is known about the factors associated with usage of HIE for radiology reports, nor about how reports are shared with an exchange network. We analyzed the system log files from a regional health information organization in upstate New York matched with insurance claims files using network analysis and regression modeling. The exchange network was dominated by a few key information sources. Outpatient users overall accessed 17 times more radiology reports than inpatient and ED users combined. Additionally, as the number of exchange partners increased per organization, the average number of reports exchanged by that organization also increased. Radiology reports were most likely to be accessed by physicians and other clinical users. These findings have implications for those operating and fostering exchange activity.
Journal of the American Medical Informatics Association : JAMIA, Jan 13, 2015
To systematically review studies assessing the effects of health information technology (health I... more To systematically review studies assessing the effects of health information technology (health IT) on patient safety outcomes. The authors employed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement methods. MEDLINE, Cumulative Index to Nursing Allied Health (CINAHL), EMBASE, and Cochrane Library databases, from 2001 to June 2012, were searched. Descriptive and comparative studies were included that involved use of health IT in a clinical setting and measured effects on patient safety outcomes. Data on setting, subjects, information technology implemented, and type of patient safety outcomes were all abstracted. The quality of the studies was evaluated by 2 independent reviewers (scored from 0 to 10). A total of 69 studies met inclusion criteria. Quality scores ranged from 1 to 9. There were 25 (36%) studies that found benefit of health IT on direct patient safety outcomes for the primary outcome measured, 43 (62%) studies that either had non-...
Journal of child neurology, Jan 30, 2015
Status epilepticus is a common neurologic emergency in children. Pediatric medical centers often ... more Status epilepticus is a common neurologic emergency in children. Pediatric medical centers often develop protocols to standardize care. Widespread adoption of electronic health records by hospitals affords the opportunity for clinicians to rapidly, and electronically evaluate protocol adherence. We reviewed the clinical data of a small sample of 7 children with status epilepticus, in order to (1) qualitatively determine the feasibility of automated data extraction and (2) demonstrate a timeline-style visualization of each patient's first 24 hours of care. Qualitatively, our observations indicate that most clinical data are well labeled in structured fields within the electronic health record, though some important information, particularly electroencephalography (EEG) data, may require manual abstraction. We conclude that a visualization that clarifies a patient's clinical course can be automatically created using the patient's electronic clinical data, supplemented with...
Neurology, Jan 26, 2015
To describe (1) the predictability of frequent emergency department (ED) use (a marker of inadequ... more To describe (1) the predictability of frequent emergency department (ED) use (a marker of inadequate disease control and/or poor access to care), and (2) the demographics, comorbidities, and use of health services of frequent ED users, among people with epilepsy. We obtained demographics, comorbidities, and 2 years of encounter data for 8,041 people with epilepsy from a health information exchange in New York City. Using a retrospective cohort design, we explored bivariate relationships between baseline characteristics (year 1) and subsequent frequent ED use (year 2). We then built, evaluated, and compared predictive models to identify frequent ED users (≥4 visits year 2), using multiple techniques (logistic regression, lasso, elastic net, CART [classification and regression trees], Random Forests, AdaBoost, support vector machines). We selected a final model based on performance and simplicity. People with epilepsy who, in year 1, were adults (rather than children or seniors), male...
Epilepsia, 2015
&quot... more "Hospital crossover" occurs when people visit multiple hospitals for care, which may cause gaps in electronic health records. Although crossover is common among people with epilepsy, the effect on subsequent use of health services is unknown. Understanding this effect will help prioritize health care delivery innovations targeted for this population. We collected de-identified information from a health information exchange network describing 7,836 people with epilepsy who visited any of seven hospitals in New York, NY from 2009-2012. Data included demographics, comorbidities, and 2 years of visit information from ambulatory, inpatient, emergency department (ED), and radiology settings. We performed two complementary retrospective cohort analyses, in order to (1) illustrate the effect on a carefully selected subgroup, and (2) confirm the effect across the study population. First, we performed a matched cohort analysis on 410 pairs of individuals with and without hospital crossover in the baseline year. Second, we performed a propensity score odds weighted ordinal logistic regression analysis to estimate the effect across all 7,836 individuals. The outcomes were the use of six health services in the follow-up year. In the matched pair analysis, baseline hospital crossover increased the odds of more visits in the ED (odds ratio 1.42, 95% confidence interval [CI] 1.05-1.95) and radiology settings (1.7, 1.22-2.38). The regression analysis confirmed the ED and radiology findings, and also suggested that crossover led to more inpatient admissions (1.35, 1.11-1.63), head CTs (1.44, 1.04-2), and brain MRIs (2.32, 1.59-3.37). Baseline hospital crossover is an independent marker for subsequent increased health service use in multiple settings among people with epilepsy. Health care delivery innovations targeted for people with epilepsy who engage in hospital crossover should prioritize (1) sharing radiology images and reports (to reduce unnecessary radiology use, particularly head CTs), and (2) improving coordination of care (to reduce unnecessary ED and inpatient use).
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, 2013
For people with epilepsy, the potential value of health information exchange (HIE) is unknown. We... more For people with epilepsy, the potential value of health information exchange (HIE) is unknown. We reviewed two years of clinical encounters for 8055 people with epilepsy from seven Manhattan hospitals. We created network graphs illustrating crossover among these hospitals for multiple encounter types, and calculated a novel metric of care fragmentation: "encounters at risk for missing clinical data." Given two hospitals, a median of 109 [range 46 - 588] patients with epilepsy had visited both. Due to this crossover, recent, relevant clinical data may be missing at the time of care frequently (44.8% of ED encounters, 34.5% inpatient, 24.9% outpatient, and 23.2% radiology). Though a smaller percentage of outpatient encounters were at risk for missing data than ED encounters, the absolute number of outpatient encounters at risk was three times higher (14,579 vs. 5041). People with epilepsy may benefit from HIE. Future HIE initiatives should prioritize outpatient access.
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, 2013
Health information exchange (HIE) systems may address the challenges that prevent easy access to ... more Health information exchange (HIE) systems may address the challenges that prevent easy access to patients' existing radiological information at the point of care. However, little is known about the factors associated with usage of HIE for radiology reports, nor about how reports are shared with an exchange network. We analyzed the system log files from a regional health information organization in upstate New York matched with insurance claims files using network analysis and regression modeling. The exchange network was dominated by a few key information sources. Outpatient users overall accessed 17 times more radiology reports than inpatient and ED users combined. Additionally, as the number of exchange partners increased per organization, the average number of reports exchanged by that organization also increased. Radiology reports were most likely to be accessed by physicians and other clinical users. These findings have implications for those operating and fostering exchang...
Seminars in pediatric neurology, 2014
We review several newer modalities to monitor the brain in children with acute neurologic disease... more We review several newer modalities to monitor the brain in children with acute neurologic disease in the pediatric intensive care unit, such as partial brain tissue oxygen tension (PbtO2), jugular venous oxygen saturation (SjvO2), near infrared spectroscopy (NIRS), thermal diffusion measurement of cerebral blood flow, cerebral microdialysis, and EEG. We then discuss the informatics challenges to acquire, consolidate, analyze, and display the data. Acquisition includes multiple data types: discrete, waveform, and continuous. Consolidation requires device interoperability and time synchronization. Analysis could include pressure reactivity index and quantitative EEG. Displays should communicate the patient's current status, longitudinal and trend information, and critical alarms.
The Journal of Physiology, 2004
Recent anatomical evidence that inhibitory interneurones receive approximately 10 times more syna... more Recent anatomical evidence that inhibitory interneurones receive approximately 10 times more synapses from mossy fibres than do principal neurones (Acsády et al. 1998) has led to the re-examination of the extent to which interneurones are involved in CA3 network excitability. Although many of the anatomical and physiological properties of mossy fibre-CA3 interneurone synapses have been previously described (Acsády et al. 1998; Tóth et al. 2000), an investigation into the quantal nature of transmission at this synapse has not yet been conducted. Here, we employed variance-mean (VM) analysis to compare the release probability, quantal size (q) and number of release sites (n) at mossy fibre target neurones in CA3. At six of seven interneurone synapses in which a high concentration of Ca2+ was experimentally imposed, the variance-mean relationship could be approximated by a parabola. Estimates of n were 1-2, and the weighted release probability in normal Ca2+ conditions ranged from 0.34 to 0.51. At pyramidal cell synapses, the variance-mean relationship approximated a linear relationship, suggesting that release probability was significantly lower. The weighted quantal amplitude was similar at interneurone synapses and pyramidal cell synapses, although the variability in quantal amplitude was larger at interneurone synapses. Mossy fibre transmission at CA3 interneurone synapses can be explained by a lower number of release sites, a broader range of release probabilities, and larger range of quantal amplitudes than at CA3 pyramidal synapses. Finally, quantal events on to interneurones elicited spike transmission, owing in part to the more depolarized membrane potential than pyramidal cells. These results suggest that although mossy fibre synapses on to pyramidal cells are associated with a larger number of release sites per synapse, the higher connectivity, higher initial release probability, and larger relative impact per quantum on to CA3 interneurones generate strong feedforward inhibition at physiological firing frequencies of dentate granule cells. Given the central role of CA3 interneurones in mossy fibre synaptic transmission, these details of mossy fibre synaptic transmission should provide insight into CA3 network dynamics under both physiological and pathophysiological circumstances.
The Journal of Physiology, 2006
Cholinergic signalling is critically involved in learning and memory processes in the hippocampus... more Cholinergic signalling is critically involved in learning and memory processes in the hippocampus, but the postsynaptic impact of cholinergic modulation on morphologically defined subtypes of hippocampal interneurones remains unclear. We investigated the influence of muscarinic receptor (mAChR) activation on stratum oriens interneurones using whole-cell patch clamp recordings from hippocampal slices in vitro. Upon somatic depolarization, mAChR activation consistently enhanced firing frequency and produced large, sustained afterdepolarizations (ADPs) of stratum oriens-lacunosum moleculare (O-LM) interneurones. In contrast, stratum oriens cell types with axon arborization patterns different from O-LM cells not only lacked large muscarinic ADPs but also appeared to exhibit distinct responses to mAChR activation. The ADP in O-LM cells, mediated by M1/M3 receptors, was associated with inhibition of an M current, inhibition of a slow calcium-activated potassium current, and activation of a calcium-dependent non-selective cationic current (ICAT). An examination of ionic conductances generated by firing revealed that calcium entry through ICAT controls the emergence of the mAChR-mediated ADP. Our results indicate that cholinergic specializations are present within anatomically distinct subpopulations of hippocampal interneurones, suggesting that there may be organizing principles to cholinergic control of GABA release in the hippocampus.
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Papers by Zachary Grinspan