Slow Correction Research Articles

Mortality and Neurologic Complications Associated with Rapid vs. Slow Correction of Severe Hyponatremia

Mortality and Neurologic Complications Associated with Rapid vs. Slow Correction of Severe Hyponatremia

A Reassessment of Sodium Correction Rates and Hospital Length of Stay Accounting for Admission Diagnosis.

Background Slow correction of severe hyponatremia has been historically recommended due to the risk of rare but catastrophic neurologic events with rapid correction. A recent study challenging this paradigm reported that rapid correction is associated with shorter hospital length of stay, but that study did not control for admission diagnosis. The objective of this study was to determine whether rapid correction is associated with shorter length of stay when controlling for admission diagnosis. Methods This retrospective cohort study is based on the fourth edition of the Medical Information Mart for Intensive Care, MIMIC-IV, a deidentified, publicly available clinical research database which includes admissions from 2008-2019. Patients were identified who presented to the hospital with initial sodium <120 mEq/L and were categorized according to total sodium correction achieved in the first day (<6 mEq/L; 6-10 mEq/L; >10 mEq/L). Linear regression was used to assess for an association between correction rate and hospital length of stay, and to determine if this association was significant when controlling for admission diagnosis classifications based on diagnosis related groups (DRGs). Results There were 419 patients with severe hyponatremia (<120 mEq/L) included in this study, of whom 374 survived to discharge. Median [IQR] hospital length of stay was 6 [4, 11] days. In a univariable linear regression, there was a trend towards a significant association between the highest rate of correction (>10 mEq/L) and shorter length of stay, as compared with a moderate rate of correction (coef. -2.764, 95% CI [-5.791, 0.263], p=0.073), but the association was not significant when controlling for admission diagnosis group (coef. -1.561, 95% CI [-4.398, 1.276], p=0.280). There was a significant association in the survivor subset (coef. -3.455, 95% CI [-6.668, -0.242], p=0.035), but it was also not significant when controlling for admission diagnosis group (coef. -2.200, 95% CI [-5.144, 0.743], p=0.142). Conclusions Rapid correction is not associated with shorter length of stay when controlling for admission diagnosis, suggesting that the disease state confounds this association. Findings from prior and future studies reporting this association should not drive clinical decision making if the confounding effect of hospital admission diagnosis and competing risk of death are not fully accounted for.

Prescaling Relaxation to Nonthermal Attractors.

We study how isotropic and homogeneous far-from-equilibrium quantum systems relax to nonthermal attractors, which are of interest for cold atoms and nuclear collisions. We demonstrate that a first-order ordinary differential equation governs the self-similar approach to nonthermal attractors, i.e., the prescaling. We also show that certain natural scaling-breaking terms induce logarithmically slow corrections that prevent the scaling exponents from reaching the constant values during the system's lifetime. We propose that, analogously to hydrodynamic attractors, the appropriate mathematical structure to describe such dynamics is the transseries. We verify our analytic predictions with state-of-the-art 2PI simulations of the large-N vector model and QCD kinetic theory.

Reflection on Clinical Decision Science: Slow surgical correction affects more than just the bowels

Reflection on how delayed colostomy reversal affects a patient's mental and physical well-being.

Rate of Correction and All-Cause Mortality in Patients With Severe Hypernatremia

Hypernatremia is common among hospitalized patients and is associated with high mortality rates. Current guidelines suggest avoiding fast correction rates but are not supported by robust data. To investigate whether there is an association between hypernatremia correction rate and patient survival. This retrospective cohort study examined data from all patients admitted to the Tel Aviv Medical Center between 2007 and 2021 who were diagnosed with severe hypernatremia (serum sodium ≥155 mmol/L) at admission or during hospitalization. Statistical analysis was performed from April 2022 to August 2023. Patients were grouped as having fast correction rates (>0.5 mmol/L/h) and slow correction rates (≤0.5 mmol/L/h) in accordance with current guidelines. All-cause 30-day mortality. A total of 4265 patients were included in this cohort, of which 2621 (61.5%) were men and 343 (8.0%) had fast correction rates; the median (IQR) age at diagnosis was 78 (64-87) years. Slow correction was associated with higher 30-day mortality compared with fast correction (50.7% [1990 of 3922] vs 31.8% [109 of 343]; P < .001). These results remained significant after adjusting for demographics (age, gender), Charlson comorbidity index, initial sodium, potassium, and creatinine levels, hospitalization in an ICU, and severe hyperglycemia (adjusted odds ratio [aOR], 2.02 [95% CI, 1.55-2.62]), regardless of whether hypernatremia was hospital acquired (aOR, 2.19 [95% CI, 1.57-3.05]) or documented on admission (aOR, 1.64 [95% CI, 1.06-2.55]). There was a strong negative correlation between absolute sodium correction during the first 24 hours following the initial documentation of severe hypernatremia and 30-day mortality (Pearson correlation coefficient, -0.80 [95% CI, -0.93 to -0.50]; P < .001). Median (IQR) hospitalization length was shorter for fast correction vs slow correction rates (5.0 [2.1-14.9] days vs 7.2 [3.5-16.1] days; P < .001). Prevalence of neurological complications was comparable for both groups, and none were attributed to fast correction rates of hypernatremia. This cohort study of patients with severe hypernatremia found that rapid correction of hypernatremia was associated with shorter hospitalizations and significantly lower patient mortality without any signs of neurologic complications. These results suggest that physicians should consider the totality of evidence when considering the optimal rates of correction for patients with severe hypernatremia.

A many-channel FPGA control system.

We describe a many-channel experiment control system based on a field-programmable gate array (FPGA). The system has 16 bit resolution on 10 analog 100 megasamples-per-second (MS/s) input channels, 14 analog 100 MS/s output channels, 16 slow analog input and output channels, dozens of digital inputs and outputs, and a touchscreen display for experiment control and monitoring. The system can support ten servo loops with 155ns latency and MHz bandwidths, in addition to as many as 30 lower bandwidth servos. We demonstrate infinite-impulse-response (IIR) proportional-integral-differential filters with 30ns latency by using only bit-shifts and additions. These IIR filters allow timing margin at 100 MS/s and use fewer FPGA resources than straightforward multiplier-based filters, facilitating many servos on a single FPGA. We present several specific applications: Hänsch-Couillaud laser locks with automatic lock acquisition and a slow dither correction of lock offsets, variable duty cycle temperature servos, and the generation of multiple synchronized arbitrary waveforms.

A memory in the bond: Green bond and sectoral investment interdependence in a fractionally cointegrated VAR framework

The urgency surrounding environmental sustainability has triggered an innovation of financing channels for climate and environmental projects. Green bond as one such channel has garnered immense interest from investors, with an implicit view that this fixed-income instrument is a relatively safer choice as an investment portfolio. Yet, the uncomfortable spread of greenwashing as a marketing spin has subjected green bonds to significant market volatility, at least as much as other financial assets or sectoral indices if not more. Whether green bonds as a financial instrument may incur losses to the extent of the loss in various sector indices, can be gauged by studying the nature of their contemporaneous growth. In this paper, we use daily data on green bonds and several S&P sectoral indices and a fractionally cointegrated vector autoregression framework (FCVAR) to study the extent to which green bonds dynamically co-move with various sectoral indices. Such a co-movement, if any, would elicit the extent to which a variation of uncertainty would determine an investor’s inclination to the diversification of a portfolio between an investment in a sectoral index and a green bond. The identifying mechanism is the shock-dissipation speed, which also informs a policymaker before choosing the right instrument to stabilise the system. We show that the system-wide shocks indeed dissipate slower than could be predicted by a conventional cointegrated VAR system. Further, the property of the slow error correction within the dynamic system of Green Bond and sectoral S&P indices, for instance, may demonstrate the speed of adjustment of the global economy to sudden shocks. Rigorous predictions exercises complement our baseline conclusions.

Correcting Hypernatremia in Children.

In children with hypernatremia, current clinical guidelines recommend a reduction in serum sodium of 0.5 mmol/L per hour or less to avoid complications of cerebral edema. However, no large-scale studies have been conducted in the pediatric setting to inform this recommendation. Therefore, this study aimed to report the association between the rate of correction of hypernatremia, neurological outcomes, and all-cause mortality in children. A retrospective cohort study was conducted from 2016 to 2019 at a quaternary pediatric center in Melbourne, Victoria, Australia. All children with at least one serum sodium level ≥150 mmol/L were identified through interrogation of the hospital's electronic medical record. Medical notes, neuroimaging reports, and electroencephalogram results were reviewed for evidence of seizures and/or cerebral edema. The peak serum sodium level was identified and correction rates over the first 24 hours and overall were calculated. Unadjusted and multivariable analyses were used to examine the association between the rate of sodium correction and neurological complications, the requirement for neurological investigation, and death. There were 402 episodes of hypernatremia among 358 children over the 3-year study period. Of these, 179 were community-acquired and 223 developed during admission. A total of 28 patients (7%) died during admission. Mortality was higher in children with hospital-acquired hypernatremia, as was the frequency of intensive care unit admission and hospital length of stay. Rapid correction (>0.5 mmol/L per hour) occurred in 200 children and was not associated with greater neurological investigation or mortality. Length of stay was longer in children who received slow correction (<0.5 mmol/L per hour). Our study did not find any evidence that rapid sodium correction was associated with greater neurological investigation, cerebral edema, seizures, or mortality; however, slow correction was associated with a longer hospital length of stay.

An automatic correction system of singing intonation based on deep learning

In order to solve the problems of low accuracy and slow correction speed in traditional singing intonation correction system, an automatic singing intonation correction system based on deep learning is proposed. In the hardware, floating-point DSP and TDSP-TF984 chip are selected as the core chips of automatic correction processor of singing intonation. The data input module and parameter calculation module of singing intonation are designed to improve the singing intonation data collector. In the software, the group delay estimation method is used to collect the singing intonation signal, and the deep learning algorithm is used to decompose the false component of the singing intonation signal. The autocorrelation function and characteristic distribution operator of the singing intonation signal are obtained to realise the singing intonation signal correction. The experimental results show that the highest accuracy of the proposed system is about 97.8%, and the shortest correction time is about 1 s.

Diferenciální diagnostika hyponatremie a hypernatremie

Dysnatremias are among the most common mineral imbalances encountered in clinical practice. Both hyponatremia and hypernatremia are associated with increased morbiditidy and mortality and represent negative prognostic factors regardless of their cause. Serum osmolality, extracellular fluid volume and sodium urine concentration are important parameters for evaluation the cause and differential diagnosis. The rate of onset of ionic disorder and severity of clinical symptoms are essential. While acute disorders with symptoms are treated immediately, in chronic disorders, thorough diagnostic evaluation and a careful approach to their correction are necessary. Especially with rapid substitution of chronic hyponatremia, there is a risk of osmotic demyelination syndrome. Therefore, a slow correction of the serum sodium level with frequent mineralogram checks is required.

Management of hypokalemia in patients with thyrotoxicosis periodic paralysis in Soetomo general hospital: A case report

The prevalence of Graves' disease varies widely between 21 and 80% of all cases of hyperthyroidism. Research conducted in 2018 at the Dr. Soetomo Regional General Hospital Surabaya found Graves' disease in as many as 66.7% of all cases of hyperthyroidism. Thyrotoxicosis Periodic Paralysis (TPP) is a disorder characterized by reversible muscle weakness and paralysis, accompanied by hypokalemia, which usually accompanies hyperthyroidism, mostly caused by Graves' disease. Management of severe hypokalemia in TPP is challenging. male, 29 years patient complained that both lower legs felt weak in the last 6 hours before coming to the hospital emergency department. The patient was diagnosed with hyperthyroidism in 2018. A fine tremor was found, and the patient was admitted to the hospital for 4 days and routinely controlled at the endocrine polyclinic. The underlying disease or causative etiology of thyrotoxicosis must be determined before treatment is conducted. The main concern when performing potassium replacement therapy is the occurrence of rebound hyperkalemia because this hypokalemia condition is caused not by total potassium depletion. The principles of management for thyrotoxicosis periodic paralysis are proper diagnosis, exclusion of other causes of paralysis, and other causes of hypokalemia, slow and gradual correction of hypokalemia, and close and careful clinical monitoring, ECG, and laboratory.

Limitations of frequency stability transfer in the near infrared using a fiber-based ring cavity.

We describe a fiber ring cavity for transferring frequency stability from a metrological optical reference at 1542 nm to tunable lasers covering 100 nm around 1.55 µm and show a stability transfer to the 10-15 level in relative value. The optical length of the ring is controlled by two actuators: a cylindrical piezoelectric tube (PZT) actuator on which a portion of the fiber is coiled and glued for fast corrections (vibrations) acting on the length of the fiber, and a Peltier module for slow corrections acting on its temperature. We characterize the stability transfer and analyze the limitations imposed by two critical effects in the setup: Brillouin backscattering and the polarization modulation generated by the electro-optic modulators (EOMs) used in the error signal detection scheme. We show that it is possible to reduce the impact of these limitations to a level below the detection threshold imposed by the servo noise. We also show that in the long term, the limitation to the stability transfer is a thermal sensitivity of -550 Hz/K/nm which could be reduced by active control of the ambient temperature.

Diagnostic and therapeutic approach to hypernatremia.

Hypernatremia occurs when the plasma sodium concentration is greater than 145mmol/L. Depending on the duration, hypernatremia can be differentiated into acute and chronic. According to severity: mild, moderate and threatening hypernatremia. Finally, depending on pathogenesis, hypernatremia can be defined as hypervolemic, hypovolemic, and euvolemic. Acute hypervolemic hypernatremia is often secondary to increased sodium intake (hypertonic NaCl and NaHCO3 solutions). Instead, chronic hypervolemic hypernatremia may be an expression of primary hyperaldosteronism. Euvolemic hypernatremia occurs in diabetes insipidus: depending on the underlying pathogenesis, it can be classified into two basic types: neurogenic (or central) and nephrogenic. The neurogenic form may be triggered by traumatic, vascular or infectious events; the nephrogenic form may be due to pharmacological causes, such as lithium, or non-pharmacological ones, such as hypokalemia. For hypovolemic hypernatremia, possible explanations are renal or extrarenal losses. The main goal of treatment of hypernatremia is the restoration of plasma tonicity. In particular, if the imbalance has occurred acutely, rapid correction improves the prognosis by preventing the effects of cellular dehydration; if hypernatremia has developed slowly, over a period of days, a slow correction rate (no more than 0.4mmol/L/h) is recommended.

Differential diagnosis of hyponatremia and hypernatremia.

Dysnatremias are among the most common mineral imbalances encountered in clinical practice. Both hyponatremia and hypernatremia are associated with increased morbiditidy and mortality and represent negative prognostic factors regardless of their cause. Serum osmolality, extracellular fluid volume and sodium urine concentration are important parameters for evaluation the cause and differential diagnosis. The rate of onset of ionic disorder and severity of clinical symptoms are essential. While acute disorders with symptoms are treated immediately, in chronic disorders, thorough diagnostic evaluation and a careful approach to their correction are necessary. Especially with rapid substitution of chronic hyponatremia, there is a risk of osmotic demyelination syndrome. Therefore, a slow correction of the serum sodium level with frequent mineralogram checks is required.

Adaptive correction of phase estimation with time based on weak measurement.

An adaptive correction algorithm is demonstrated based on weak measurement, which introduces a feedback and an additional interaction to the system and can dynamically adjust the operating point in accordance with the condition of the estimated phase change. Two schemes, fast adaptive correction and slow adaptive correction, are proposed for different conditions of the modulation device. Fast adaptive correction scheme can realize a real-time correction and maintain the high sensitivity. Slow adaptive correction scheme, as a supplement, can correct the distortion of the measured parameter by changing the measuring period. These two schemes are useful for high precision phase estimation with time in modern physics and practical applications, including, but not limited to, timing synchronization, accurate distance measurement, and gravity wave detection. Moreover, we discuss the deviation of the adaptive correction for considering system noise in practical measurement.

Approach to the Management of Hypernatraemia in Older Hospitalised Patients.

Hypernatraemia is associated with high morbidity and mortality and is more common in patients of older age, nursing home residents and those with cognitive impairment and restricted mobility. The most common cause in hospital settings is water dehydration due to reduced intake although other causes should be identified. Once identified, prompt management is necessary to avoid delayed correction as prolonged hypernatremia is associated with increased hospital stay and mortality. Comprehensive history-taking and physical examination, basic investigations and medication review are essential to identify causative and remediable factors in those admitted with hypernatraemia. Accurate calculation of fluid deficit and ongoing losses is essential in order to ensure adequate fluid replacement, The administration of appropriate, usually hypotonic, fluids is also essential to the timely restoration of eunatraemia. Although evidence of definite harm resulting from rapid correction is lacking, a serum sodium reduction rate of <12 mmol/l day is advised with the caveat that close monitoring of electrolytes is required to ensure the desired correction rate is being achieved. Medical and nursing professionals should have access to a local hospital protocol to guide management of patients with hypernatraemia to improve patient outcomes and mitigate the risk of harm, particularly from under-recognition and slow correction.

Modulation and Feed-Forward Based Damping Matching Strategy for Linear Generators

This article presents an active damping matching control strategy to optimize the output power of linear generators in energy harvesting applications. The method adjusts the magnitude of the current command responsible for active power set-point. The proposed approach combines a simple model-based feed-forward term with a slow but accurate correction based on the response of output power to a low-frequency modulation in set-point current magnitude. The correction is derived from the phase of output power oscillations and used to adjust the power set-point to achieve active-load matching conditions. In order to remove the low-frequency oscillations in the power at steady state, the method automatically stops the current amplitude modulation when maximum output power is reached. In addition, the proposed control incorporates an overstroke protection, which increases the active current component thereby reducing the stroke rapidly to a safe limit. The overall control principle is validated experimentally.

Simple carrier-envelope phase control and stabilization scheme for difference frequency generation-based systems.

We report about a setup for carrier-envelope phase (CEP) control and stabilization in passive systems based on difference frequency generation (DFG). The principle of this approach relies on the amplitude to phase modulation transfer in the white-light generation process. A small modulation of the pump laser intensity is used to obtain a DFG output modulated in CEP. This technique is demonstrated in a CEP-stable system pumped by an Yb-doped fiber amplifier. It is first characterized by measuring CEP modulations produced by applying arbitrary waveforms. The CEP actuator is then used for slow drifts correction in a feedback loop. The results show the capability of this simple approach for OPA/OPCPA CEP-stabilized setups.

Clinical Faceoff: The Complex Tibial Plafond Fracture: ORIF or Circular External Fixation?

Clinical Faceoff: The Complex Tibial Plafond Fracture: ORIF or Circular External Fixation?

Erythropoietin-Induced Hypertension: A Review of Pathogenesis, Treatment, and Role of Blood Viscosity.

Anemia is a common complication of certain chronic diseases and can be treated by stimulating hematopoietic cells to increase red blood cell count, and this action is achieved by recombinant human erythropoietin. In this review article, we have discussed about hypertension, which develops as a result of erythropoietin therapy. We have explored the pathogenesis of erythropoietin-induced hypertension and discussed some ways to prevent and treat this condition. Also, an attempt has been made to find out the role of blood viscosity in erythropoietin-induced hypertension. We conducted a comprehensive review of literature by collecting data from online databases like PubMed and Google Scholar. We mainly studied clinical trials that unraveled the mechanism of hypertension caused by erythropoietin. Hypertension is mainly caused due to enhanced vascular responsiveness to constrictors and impaired action of vasodilators. Role of blood viscosity in the pathogenesis of hypertension is doubtful due to the lack of consistency in the studies. Incidence of hypertension can be reduced by achieving slow correction of anemia and by switching to subcutaneous route of administration. Conventional anti-hypertensives have been found to be beneficial in the treatment. In some severe and persistent cases, temporary discontinuation of erythropoietin may be needed.