Perinatal risk factors for late neonatal severe acute kidney injury in very low birth weight infants: a retrospective study.

This study aimed to identify the perinatal risk factors of severe acute kidney injury (AKI) occurring after the first week of birth in very low birth weight (VLBW) infants who survived up to the first week. We conducted a single-center, retrospective cohort study on VLBW infants (birth weight, <1,500 g) delivered at <32 weeks of gestational age (GA) from January 2012 to December 2022. We classified AKI based on changes in serum creatinine and urine output based on the modified The Kidney Disease: improving Global Outcomes (KDIGO) neonatal AKI criteria. Stage 2-3 AKI were considered as severe AKI (sAKI). We performed logistic regression analysis to evaluate risk factors for late neonatal severe AKI identified in the second week after birth. We included 274 VLBW infants. The prevalence of late neonatal severe AKI (sAKI) was 27.4%, with the diagnosis rate of sAKI being higher early after birth. Logistic regression analysis revealed that the factors associated with late neonatal sAKI were small for gestational age (SGA) (OR, 3.02; P = 0.032), endotracheal intubation in the delivery room (OR, 2.79; P = 0.022), necrotizing enterocolitis (NEC) (OR, 12.41; P = 0.029), and decreased minimum weekly fluid balance <0 (OR, 2.97; P = 0.012). SGA, intubation in the delivery room, and NEC were associated factors for late neonatal sAKI in VLBW infants. The association of no weekly weight gain with increased late neonatal sAKI risk indicates its use in guiding fluid therapy and aids in biomarker research.

Diuretic responses to Ringer's solution and 20% albumin at different arterial pressures.

Intravenous volume loading is a common treatment when hypovolemia is a potential cause of oliguria. We studied whether the effectiveness of Ringer's solution and 20% albumin in inducing diuresis differs depending on the mean arterial pressure (MAP). For this purpose, volume kinetic analysis was performed based on urine output and hemoglobin-derived plasma dilution obtained during and after 136 infusions of Ringer and 85 infusions of 20% albumin. Covariance analysis quantified the diuretic response at different arterial pressures. The results show that the diuretic response to a known plasma volume expansion was greater for Ringer's solution above a MAP of 70 mmHg, while 20% albumin was significantly more effective at lower pressures (p < 0.03). Simulations of the urinary output in response to infusion of a predefined fluid volume yielded superior efficacy for 20% albumin when the MAP was low, while Ringer's was similarly effective when the MAP averaged 100 mmHg. In conclusion, urine output in response to plasma volume expansion with 20% albumin was similar to, or even stronger, than that of Ringer's solution when the MAP was below 70 mmHg.

Relationships between Morning Thirst and Later Hydration Status and Total Water Intake.

Purpose: To investigate the effects of thirst on later hydration status, total water intake (TWI-MA), and its potential sex differences. Methods: Twelve men (mean ± standard deviation; age: 21 ± 2 years; mass: 81.0 ± 15.9 kg) and twelve women (age: 22 ± 3 years; mass: 68.8 ± 15.2 kg) visited the laboratory in the morning (first thing in the morning) and afternoon (2:00-4:00 p.m.) for three consecutive days under a free-living condition. At each visit, urine osmolality (UOSM), urine specific gravity (USG), urine color (UCOL), body mass loss (BML), thirst, and plasma osmolality (POSM) were collected and analyzed. The participants recorded their food and fluid intake between the visits to determine TWI-MA. Linear regression was used to predict the effect of morning thirst on the afternoon hydration indices for all the participants, as well as for males and females separately. Results: Higher morning thirst predicted lower UOSM (r2 = 0.056, p = 0.045), USG (r2 = 0.096, p = 0.008), UCOL (r2 = 0.074, p = 0.021), and higher thirst (r2 = 0.074, p = 0.021) in the afternoon. However, morning thirst did not predict afternoon BML, POSM, or TWI-MA (p > 0.05). In males, higher morning thirst predicted lower afternoon UOSM (r2 = 0.130, p = 0.031) and USG (r2 = 0.153, p = 0.018). Additionally, higher morning thirst predicted higher TWI-MA (r2 = 0.154, p = 0.018) in females. Conclusions: Morning thirst had a negligible impact on later hydration status, specifically with afternoon urine indices. Furthermore, higher thirst sensation did not impact BML, POSM, or TWI-MA. However, thirst sensation minimally contributed to drinking behavior in females. Overall, individuals may not rely solely on thirst sensation to manipulate their drinking behavior to optimize their fluid balance during their daily lives due to the complexity of thirst mechanisms.

Evolution of the thirst mechanism in Homo: The need and limitations of thirst and hydration.

There is a view that the perception of thirst and actual body fluid balance may affect cognitive and exercise performance. The evolutionary evidence suggests that our survival was dependent on our ability to sweat profusely when hunting during the heat of the day (persistence hunting), so if water deficits were not tolerated, consequently the thirst mechanism would limit our persistence hunting capability. This also means that hunting and searching for water was undertaken with some extent of water deficit, and in turn suggests that performance; physical and cognitive, was conducted with a degree of dehydration. Given the current views on the maintenance of body water for performance, there is a need to evaluate the evidence relating to tolerance limits for water deficits with respect to both physical and cognitive performance. This review considers the thirst mechanism and the conditions and selective pressures under which this might have evolved. Consideration will be given to how the thirst mechanism influences our physical and cognitive performance. The review suggests that Homo developed appropriate tolerances for water deficits and thirst perception, with a safety margin that prevented detrimental declines in physical and cognitive performance to the point of inhibiting corrective action. This would have offered a selective advantage, enabling the search for water and functioning adequately during periods of water scarcity.

Postoperative Fluid Accumulation is Associated With Underestimation of AKI Severity in Lung Transplant Recipients.

BACKGROUND: Post-lung transplantation (LTx) fluid accumulation can lead to dilution of serum creatinine (SCr). We hypothesized that fluid accumulation might impact the diagnosis, staging, and outcome of posttransplant acute kidney injury (AKI). METHODS: In this retrospective study, we analyzed data from 131 adult LTx patients at a single German lung center between 2005 and 2018. We assessed the occurrence of AKI within 7 days posttransplant, both before and after SCr-adjustment for fluid balance (FB), and investigated its impact on all-cause mortality. Transient and persistent AKIs were defined as return to baseline kidney function or continuation of AKI beyond 72 h of onset, respectively. RESULTS: AKI was diagnosed in 58.8% of patients according to crude SCr values. When considering FB-adjusted SCr values, AKI severity was underestimated in 20.6% of patients, that is, AKI was detected in an additional 6.9% of patients and led to AKI upstaging in 23.4% of cases. Patients initially underestimated but detected with AKI only after FB adjustment had higher mortality compared to those who did not meet AKI criteria (hazard ratio [HR] 2.98; 95% confidence interval [CI] 1.06, 8.36; p = 0.038). Persistent AKI was associated with higher mortality than transient AKI, regardless of using crude or adjusted SCr values (p < 0.05). Persistent AKI emerged as an independent risk factor for mortality (HR 2.35; 95% CI 1.29, 4.30; p = 0.005). CONCLUSION: Adjusting for FB and evaluating renal recovery patterns post-AKI may enhance the sensitivity of AKI detection. This approach could help identify patients with poor prognosis and potentially improve outcomes in lung transplant recipients. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03039959, NCT03046277.

Impact of different intravenous bolus rates on fluid and electrolyte balance and mortality in critically ill patients.

The effect of intravenous bolus rates on patient outcomes is a complex and crucial aspect of critical care. Fluid challenges are commonly used in critically ill patients to manage their hemodynamic status, but there is limited information available on the specifics of when, how much, and at what rate fluids should be administered during these challenges. The aim of this review is to thoroughly examine the relationship between intravenous bolus rates, fluid-electrolyte balance, and mortality and to analyze key research findings and methodologies to understand these complex dynamics better. Fluid challenges are commonly employed in managing hemodynamic status in this population, yet there is limited information on the optimal timing, volume, and rate of fluid administration. Utilizing a narrative review approach, the analysis identified nine relevant studies that investigate these variables. The findings underscore the importance of a precise and individualized approach in clinical settings, highlighting the need to tailor intravenous bolus rates to each patient's specific needs to maximize outcomes. This review provides valuable insights that can inform and optimize clinical practices in critical care, emphasizing the necessity of meticulous and exact strategies in fluid administration.

The Urine Output Response to Low-Dose Diuretic Challenge Predicts Tolerance to Negative Fluid Balance in Mechanically Ventilated, Critically Ill Patients.

Background and objective Although early diuretic use and negative fluid balance (NFB) have been associated with lower mortality in mechanically ventilated patients, some patients are not tolerant to NFB. Little is known about whether urine output response after the diuretic administration predicts NFB tolerance in mechanically ventilated patients. Hence, we conducted this study to look into this. Methods This was a single-center, prospective, observational study. We included mechanically ventilated patients who were hemodynamically stable with bilateral pulmonary opacities on chest radiography and planned to be diuresed per our fluid removal protocol. In the protocol, a low dose of furosemide adjusted to each patient's estimated glomerular filtration rate (eGFR) was administered, and then we started to measure urine outputs hourly for four hours. Tolerance to NFB was defined as "absence of hypotension, fluid resuscitation and vasopressors use, and acute kidney injury during fluid removal". We investigated whether the urine output predicts the tolerance to NFB during fluid removal treatment. Results A total of 60 mechanically ventilated patients were included. Notably, 80% (48/60) of the patients were tolerant to NFB. All hourly and cumulative urine output measurements during the first four hours after the first diuretic administration were significantly higher in the NFB-tolerant group than in the non-tolerant group. Among all hourly and cumulative urine output measurements, the first four-hour cumulative urine output showed the highest area under the receiver operating characteristic curve (AUC) of 0.83 for predicting the tolerance to NFB. Multivariate logistic regression analysis adjusted for the urine output two hours before the diuretic use showed that each 100-mL increase in the first four-hour cumulative urine output was significantly associated with an increased odds ratio (OR) of the tolerance to NFB [adjusted odds ratio (aOR): 1.53; 95% CI: 1.11-2.15]. Conclusions Based on our findings, the first four-hour cumulative urine output after the first low dose of diuretic administration might help predict tolerance to NFB during fluid removal treatment in mechanically ventilated, critically ill patients.

Relative Blood Volume Monitoring during Continuous Renal Replacement Therapy: A Prospective Observational Study.

INTRODUCTION: Hematocrit monitoring during continuous renal replacement therapy (CRRT) allows the continuous estimation of relative blood volume (RBV). This may enable early detection of intravascular volume depletion prior to clinical sequelae. We aimed to investigate the feasibility of extended RBV monitoring and its epidemiology during usual CRRT management by clinicians unaware of RBV. Moreover, we studied the association between changes in RBV and net ultrafiltration (NUF) rates. METHODS: In a cohort of adult intensive care unit patients receiving CRRT, we continuously monitored hematocrit and RBV using a pre-filter noninvasive optical sensor. We analyzed temporal changes in RBV and investigated the association between RBV change and NUF rates, using the classification of NUF rates into low, moderate, or high based on predefined cut-offs. RESULTS: We obtained >60,000 minute-by-minute measurements in >1,000 CRRT hours in 36 patients. The median RBV change was negative (decrease) in 69% of patients and the median peak change in RBV was -9.3% (interquartile range: -3.9% to -14.3%). Moreover, the median RBV decreased from baseline by >5% in 40.2% of measurements and by >10% in 20.6% of measurements. Finally, RBV decreased significantly more when patients received a high NUF rate (>1.75 mL/kg/h) compared to low or moderate NUF rates (5.32% vs. 1.93% or 1.97%, p < 0.001). CONCLUSION: Continuous hematocrit and RBV monitoring during CRRT was feasible. RBV decreased significantly during CRRT, and decreases were greater with higher NUF rates. RBV monitoring may help optimize NUF management and prevent the occurrence of intravascular volume depletion.

Machine learning-based prognostic model for in-hospital mortality of aortic dissection: Insights from an intensive care medicine perspective.

Objective: Aortic dissection (AD) is a severe emergency with high morbidity and mortality, necessitating strict monitoring and management. This retrospective study aimed to identify prognostic factors and establish predictive models for in-hospital mortality among AD patients in the intensive care unit (ICU). Methods: We retrieved ICU admission records of AD patients from the Medical Information Mart for Intensive Care (MIMIC)-IV critical care data set and the eICU Collaborative Research Database. Functional data analysis was further applied to estimate continuous vital sign processes, and variables associated with in-hospital mortality were identified through univariate analyses. Subsequently, we employed multivariable logistic regression and machine learning techniques, including simple decision tree, random forest (RF), and eXtreme Gradient Boosting (XGBoost) to develop prognostic models for in-hospital mortality. Results: Given 643 ICU admissions from MIMIC-IV and 501 admissions from eICU, 29 and 28 prognostic factors were identified from each database through univariate analyses, respectively. For prognostic model construction, 507 MIMIC-IV admissions were divided into 406 (80%) for training and 101 (20%) for internal validation, and 87 eICU admissions were included as an external validation group. Of the four models tested, the RF consistently exhibited the best performance among different variable subsets, boasting area under the receiver operating characteristic curves of 0.870 and 0.850. The models highlighted the mean 24-h fluid intake as the most potent prognostic factor. Conclusions: The current prognostic models effectively forecasted in-hospital mortality among AD patients, and they pinpointed noteworthy prognostic factors, including initial blood pressure upon ICU admission and mean 24-h fluid intake.

Fluid excess on intensive care unit after mechanical thrombectomy after acute ischemic stroke is associated with unfavorable neurological and functional outcomes: An observational cohort study.

INTRODUCTION: Endovascular thrombectomy stands as a pivotal component in the standard care for patients experiencing acute ischemic stroke with large vessel occlusion. Subsequent care for patients often extends to a neurological intensive care unit. While fluid management is integral to intensive care, the association between early fluid balance and neurological and functional outcomes post-thrombectomy has not yet been thoroughly investigated. METHODS: In a retrospective analysis of an observational, single-center study spanning from 2015 to 2021 at the University Medical Center Hamburg-Eppendorf, Germany, we enrolled stroke patients who underwent thrombectomy and received subsequent treatment in the ICU. Unfavorable functional and neurological outcome was defined as a mRS > 2 on day 90 after admission (mRS d90) or NIHSS > 5 at discharge, respectively. A multivariate regression model, adjusting for confounders, utilized the average fluid balance in the first 5 days to predict outcomes. Patients were dichotomized by their average fluid balance (>1 L vs <1 L) within the first 5 days, and a multivariate mRS d90 shift analysis was conducted after adjusting for covariates. RESULTS: Between 2015 and 2021, 1252 patients underwent thrombectomy, and 553 patients met the inclusion criteria (299 women [54%]). Unfavorable functional outcome was significantly associated with a higher daily average fluid balance in the first 5 days in the ICU (mRS d90 ⩽ 2: 0.3 ± 0.5 L, mRS d90 > 2: 0.7 ± 0.7 L, p = 0.02). The same association was observed for the NIHSS at discharge (NIHSS ⩽ 5: 0.3 ± 0.5 L; NIHSS > 5: 0.6 ± 0.6 L; p = 0.03). The mRS d90 shift analysis revealed significance for patients with an average fluid balance <1 L for better functional outcomes (adjusted odds ratio [AOR] 2.17; 95% confidence interval [CI] 1.54-3.07; p < 0.01). DISCUSSION: Fluid retention in post-thrombectomy stroke patients in the ICU is associated with poorer functional and neurological outcomes. Consequently, fluid retention emerges as an additional potential predictor for post-intervention stroke outcomes. Our findings provide an initial indication that preventing excessive fluid retention in stroke patients after endovascular thrombectomy could be beneficial for both functional and neurological recovery. Therefore, fluid retention might be an element to consider in optimizing fluid management for stroke patients.

Preload responsiveness-guided fluid removal in mechanically ventilated patients with fluid overload: A comprehensive clinical-physiological study.

This study investigated fluid removal strategies for critically ill patients with fluid overload on mechanical ventilation. Traditionally, a negative fluid balance (FB) is aimed for. However, this approach can have drawbacks. Here, we compared a new approach, namely removing fluids until patients become fluid responsive (FR) to the traditional empiric negative balance approach. Twelve patients were placed in each group (n = 24). FR assessment was performed using passive leg raising (PLR). Both groups maintained stable blood pressure and heart function during fluid management. Notably, the FR group weaned from the ventilator significantly faster than negative FB group (both for a spontaneous breathing trial (14 h vs. 36 h, p = 0.031) and extubation (26 h vs. 57 h, p = 0.007); the difference in total ventilator time wasn't statistically significant (49 h vs. 62 h, p = 0.065). Additionally, FR group avoided metabolic problems like secondary alkalosis and potential hypokalemia seen in the negative FB group. FR-guided fluid-removal in fluid overloaded mechanically ventilated patients was a feasible, safe, and maybe superior strategy in facilitating weaning and disconnection from mechanical ventilation than negative FB-driven fluid removal. FR is a safe endpoint for optimizing cardiac function and preventing adverse consequences during fluid removal.

Ultrasound based estimate of central venous pressure: Are we any closer?

Central venous pressure (CVP) serves as a direct approximation of right atrial pressure and is influenced by factors like total blood volume, venous compliance, cardiac output, and orthostasis. Normal CVP falls within 8-12 mmHg but varies with volume status and venous compliance. Monitoring and managing disturbances in CVP are vital in patients with circulatory shock or fluid disturbances. Elevated CVP can lead to fluid accumulation in the interstitial space, impairing venous return and reducing cardiac preload. While pulmonary artery catheterization and central venous catheter obtained measurements are considered to be more accurate, they carry risk of complications and their usage has not shown clinical improvement. Ultrasound-based assessment of the internal jugular vein (IJV) offers real-time, non-invasive measurement of static and dynamic parameters for estimating CVP. IJV parameters, including diameter and ratio, has demonstrated good correlation with CVP. Despite significant advancements in non-invasive CVP measurement, a reliable tool is yet to be found. Present methods can offer reasonable guidance in assessing CVP, provided their limitations are acknowledged.

Understanding body fluid balance, dehydration and intravenous fluid therapy.

This article examines the role of water in the body, the balance of fluids in the body and the provision of intravenous (IV) fluids to patients who are dehydrated, providing a comprehensive overview of these topics for nurses. The author details various aspects of practice in IV fluid therapy, including the types of fluids used, their indications, administration and potential side effects. The article also discusses dehydration and how nurses can identify and treat this complication, which can occur as a result of many different conditions. Drawing on the relevant research, this article aims to advance nurses' knowledge of the care of patients who are dehydrated and require IV fluid therapy.

Intravenous fluid therapy: an audit and discussion of improvements required for prescribers and administrators.

BACKGROUND: Foundation doctors and nurses are the clinicians most closely involved in fluid assessment, intravenous (IV) fluid prescription and administration. However, both groups report challenges regarding IV fluids. At a large NHS trust in England, adherence to the National Institute for Health and Care Excellence (NICE) guideline CG174, regarding IV fluids, was largely unknown. AIMS: To assess the baseline adherence, within the hospitals, to CG174 and identify areas for improvement. METHODS: A set of 12 audit standards were developed and used to collect data across 29 clinical areas between September 2022 and May 2023, with 255 patients receiving IV fluids at any time during their inpatient stay included. FINDINGS: For two standards target adherence of 95% was achieved, with an adherence less than 50% in most. Areas of particularly poor adherence included assessing and meeting fluid and electrolyte requirements, patient reassessment and developing IV fluid management plans. CONCLUSION: Trust baseline adherence to NICE CG174 requires improvement, particularly regarding patient assessment and reassessment, and meeting electrolyte requirements.

Paediatric postoperative acute kidney injury after non-cardiac surgery: Protocol for a systematic review and meta-analysis.

BACKGROUND: Paediatric acute kidney injury (AKI) is associated with significant adverse outcomes such as increased mortality, progression to chronic kidney disease and longer length of stay in hospital. Postoperative AKI is a common and recognized complication after surgery in adults. In the paediatric population, AKI postoperatively to cardiac surgery has been extensively studied. However, the incidence of postoperative AKI after non-cardiac surgery is less clear. Therefore, we aim to assess the available literature on this topic. METHODS: We will conduct a systematic review of observational and randomized controlled trials assessing the incidence of paediatric postoperative AKI after non-cardiac surgery. Pairs of reviewers will independently screen the literature and extract data and assess risk of bias from eligible studies. The databases Pubmed, Cochrane and Web of Sciences will be searched. We will conduct the review in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach. If sufficient homogeneity within the included trials we will conduct meta-analyses. DISCUSSION: This systematic review aims to investigate the incidence of postoperative AKI in the paediatric non-cardiac surgery population. The results of this review will provide a foundation for future research in the field of paediatric postoperative AKI.

Perioperative fluid balance and early acute kidney injury after lung transplantation.

BACKGROUND: Postoperative acute kidney injury (AKI) after lung transplantation (LTx) is an important factor affecting the short-term outcomes. The focus item of transplantation centers is how to improve the incidence of AKI through optimal management during the perioperative period. OBJECTIVE: The purpose of the study is to investigate the influence of perioperative volume in the development of early AKI following LTx. METHOD: The study involved patients who had undergone LTx between October 2018 to December 2021 at China-Japan Friendship Hospital in Beijing. The patients were monitored for AKI occurring within 72 hours after LTx, as well as the renal outcomes within 30 days. The perioperative volumes were compared and analyzed to determine the impact on various clinical outcomes. RESULTS: 248 patients were enrolled in the study ultimately, with almost half of them (49.6 %) experiencing AKI. 48.8 % of AKI patients received continuous renal replacement therapy (CRRT), with 57.7 % recovered by the end of the 30-day follow-up period. A J-shaped relationship was demonstrated between perioperative volume and AKI incidence. Moreover, maintaining a positive fluid balance would increase the 30-day mortality and lead to poor renal outcomes. CONCLUSION: Perioperative volume is an independent risk factor of early AKI after LTx. Positive fluid balance increases the risk of AKI, 30-day mortality, and adverse renal prognosis. The LTx recipients may benefit from a relatively restrict fluid strategy during and after the lung transplantation.

Hypocalcemia in the Immediate Postoperative Period Following Metabolic Bariatric Surgery - Hype or Harm?

PURPOSE: Hypocalcemia post-metabolic bariatric surgery (MBS) is a known long-term complication after hypoabsorptive procedures. However, data on immediate postoperative calcium are limited. Our aim was to evaluate the prevalence of hypocalcemia on the 1st postoperative day after MBS and correlate it with potential associated factors. MATERIALS AND METHODS: We analyzed data from all consecutive index MBS over 1 year. We collected data on demographics and on preoperative and postoperative values of serum calcium (TC), albumin, adjusted calcium (AC-Payne formula), magnesium, phosphorus, preoperative vitamin-D, and postoperative 24-h urine output, intravenous fluids (IVF), bolus intravenous furosemide, and creatine phosphokinase (CPK). Continuous data are expressed as means ± SD (range). Categorical data are presented as frequencies (%). Linear regression was implemented to designate potential correlations. RESULTS: The cohort included 86 patients (58.1% females). The mean preoperative TC was 9.4mg/dL ± 0.4 (8.5-10.5) and mean postoperative TC 7.8mg/dL ± 0.6 (6.3-9.3, 17.0% decrease). The mean preoperative AC was 10.1mg/dL ± 0.4 (9.2-11.2) and mean postoperative AC 8.5mg/dL ± 0.6 (7.0-10.0, 15.8% decrease). Seventy-three patients (84.8%) had abnormally low TC (< 8.5mg/dL), and 43 (50%) abnormally low AC. There was only weak correlation between postoperative TC and AC with magnesium (r = 0.258), phosphorus (r = 0.269), vitamin-D (-0.163), 24-h urine output (r = -0.168), IVF (r = -0.237), bolus furosemide (r = 0.155), and mean operative time (r = 0.010). CONCLUSIONS: In our cohort of patients, hypocalcemia was a real problem but we did not find any significant correlation with the examined factors. Further studies are warranted to validate our findings and investigate other potential correlations.

Hemodialysis Procedures for Stable Incident and Prevalent Patients Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance.

The demographic profile of patients transitioning from chronic kidney disease to kidney replacement therapy is changing, with a higher prevalence of aging patients with multiple comorbidities such as diabetes mellitus and heart failure. Cardiovascular disease remains the leading cause of mortality in this population, exacerbated by the cardiovascular stress imposed by the HD procedure. The first year after transitioning to hemodialysis is associated with increased risks of hospitalization and mortality, particularly within the first 90-120 days, with greater vulnerability observed among the elderly. Based on data from clinics in Fresenius Medical Care Europe, Middle East, and Africa NephroCare, this review aims to optimize hemodialysis procedures to reduce mortality risk in stable incident and prevalent patients. It addresses critical aspects such as treatment duration, frequency, choice of dialysis membrane, dialysate composition, blood and dialysate flow rates, electrolyte composition, temperature control, target weight management, dialysis adequacy, and additional protocols, with a focus on mitigating prevalent intradialytic complications, particularly intradialytic hypotension prevention.

Utility of copeptin in predicting non-pathological postoperative polyuria in patients affected by acromegaly undergoing pituitary neurosurgery.

PURPOSE: Copeptin efficiently predicts post-neurosurgical central diabetes insipidus (CDI) in patients with hypothalamic-pituitary lesions, but its role in characterizing changes in diuresis in individuals with acromegaly undergoing neurosurgery remains unexplored. Our study aimed to assess changes in postoperative fluid balance in acromegaly patients and correlate them with both copeptin and growth hormone (GH) levels. METHODS: This was a secondary analysis of a prospective study involving 15 acromegaly patients undergoing endoscopic endonasal resection at our University Hospital. Fluid balance was assessed daily, and copeptin and GH levels were evaluated preoperatively (T0), and serially on the morning of the first (T2) and second (T3) postoperative day, with an additional measurement of copeptin one hour post-extubation (T1). Patients with pre-existing or post-neurosurgical CDI were excluded from the analysis. RESULTS: Most patients (11/15) exhibited a negative fluid balance on the second postoperative day, with 4 developing polyuria. Postoperative GH levels did not differ significantly between polyuric and non-polyuric patients, but GH measured at T2 correlated significantly with negative total balance (r = -0.519, p = 0.048). Copeptin levels at T1 were significantly higher in those who developed polyuria (p = 0.013), and a copeptin value > 39.9 pmol/L at T1 showed excellent ability (Sensitivity 100%, Specificity 90.9%, p < 0.001) in predicting postoperative polyuria. Additionally, polyuric patients exhibited a higher T1 / T3 copeptin ratio (p = 0.013) and a negative fluid balance was associated with the remission of acromegaly at 12 months (p = 0.046). CONCLUSION: The early assessment of copeptin, in addition to facilitating the rapid identification of individuals at increased risk of developing CDI, could also allow the recognition of subjects with a tendency towards non-pathological polyuria in the postoperative setting, at least in individuals affected by acromegaly.

Fluid distribution during surgery in the flat recumbent, Trendelenburg, and the reverse Trendelenburg body positions.

BACKGROUND: The distribution and elimination of infused crystalloid fluid is known to be affected by general anesthesia, but it is unclear whether changes differ depending on whether the patient is operated in the flat recumbent position, the Trendelenburg ("legs up") position, or the reverse Trendelenburg ("head up") position. METHODS: Retrospective data on hemodilution and urine output obtained during and after infusion of 1-2 L of Ringer's solution over 30-60 min were collected from 61 patients undergoing surgery under general anesthesia and 106 volunteers matched with respect to the infusion volume and infusion time. Parameters describing fluid distribution in the anesthetized and awake subjects were compared by population volume kinetic analysis. RESULTS: General anesthesia decreased the rate constant for urine output by 79% (flat recumbent), 91% (legs up) and 91% (head up), suggesting that laparoscopic surgery per se intensified the already strong anesthesia-induced fluid retention. General anesthesia also decreased the rate constant governing the return of the distributed fluid to the plasma by 32%, 15%, and 70%, respectively. These results agree with laboratory data showing a depressive effect of anesthetic drugs on lymphatic pumping, and further suggest that the "legs up" position facilitates lymphatic flow, whereas the "head up" position slows this flow. Both Trendelenburg positions increased swelling of the "third fluid space". CONCLUSIONS: General anesthesia caused retention of infused fluid with preferential distribution to the extravascular space. Both Trendelenburg positions had a modifying influence on the kinetic adaptations that agreed with the gravitational forces inflicted by tilting to body.