Plasma hyperosmolality during cardiopulmonary bypass is a risk factor for postoperative acute kidney injury: Results from double blind randomised controlled trial.

INTRODUCTION: The study objective was to investigate whether a Ringer's acetate based priming solution with addition of Mannitol and sodium concentrate increases the risk of cardiac surgery associated kidney injury (CSA-AKI). METHODS: This is a double blind, prospective randomized controlled trial from a single tertiary teaching hospital in Sweden including patients aged ≥65 years (n = 195) admitted for routine cardiac surgery with cardiopulmonary bypass. Patients in the study group received Ringer's acetate 1000 mL + 400 mL Mannitol (60 g) + sodium chloride 40 mL (160 mmol) and heparin 2 mL (10 000 IU) 966 mOsmol (n = 98), while patients in the control group received Ringer's acetate 1400 mL + heparin 2 mL (10 000 IU), 388 mOsmol (n = 97) as pump prime. Acute kidney injury was analysed based on the Kidney Disease Improving Outcomes (KDIGO 1-3) definition. RESULTS: The overall incidence of CSA-AKI (KDIGO stage 1) was 2.6% on day 1 in the ICU and 5.6% on day 3, postoperatively. The serum creatinine level did not show any postoperative intergroup differences, when compared to baseline preoperative values. Six patients in the Ringer and five patients in the Mannitol group developed CSA-AKI (KDIGO 1-3), all with glomerular filtration rates <60 mL/min/1.73 m2. These patients showed significantly higher plasma osmolality levels compared to preoperative values. Hyperosmolality together with patient age and the duration of the surgery were independent risk factors for postoperative acute kidney injury (KDIGO 1-3). CONCLUSIONS: The use of a hyperosmolar prime solution did not increase the incidence of postoperative CSA-AKI in this study, while high plasma osmolality alone increased the associated risk by 30%. The data suggests further examination of plasma hyperosmolality as a relative risk factor of CSA-AKI.

Filling In the Gaps: Ethylene Glycol Poisoning Presenting With Isolated Lactate and Osmolar Gaps.

Ethylene glycol (EG) is an organic compound used in antifreeze. In 2020 alone, there were 5,277 EG exposures, with only 617 reported as intentional ingestions. Therefore, encountering EG toxicity is rare; however, it is essential to identify it promptly based on a focused history, exam, and rapid identification of commonly associated EG-induced metabolic derangements. If the diagnosis is not made within 12 hours of ingestion or exposure, severe morbidity and mortality can occur. Previous reports of EG poisoning have occurred in the setting of a lactate gap (LG) and osmolar gap (OG); however, they also had commonly associated findings of EG toxicity such as high anion gap acidosis (HAGMA), acute kidney injury (AKI), hypocalcemia, calcium oxalate stones, and suggestive histories of EG ingestion. We present a case of a 57-year-old male who presented from home for slurred speech and gait imbalance. He was intubated for airway protection due to obtundation. Labs only revealed the presence of both LG and OG, non-anion gap acidosis (NAGMA), and an EG level of 112 mg/dL three days after admission. Hemodialysis (HD) was initiated solely based on these findings within eight hours of admission, and he was subsequently able to be extubated without developing an acute or chronic cardio-pulmonary or renal injury. The patient's partner reported to the care team that they found multiple empty bottles of rum and whisky, an empty anti-freeze bottle, and a Sprite bottle with a light blue substance that was nearly empty in their basement. After extubation, the patient admitted to ingesting the antifreeze with the intention of self-harm. He recovered without complication and was transferred to the inpatient psychiatric unit to manage his depression and suicidality further. The early diagnosis and treatment of EG poisoning is critical to prevent severe morbidity and mortality occurring only 12 hours after ingestion. Therefore, reliance on prompt recognition of common laboratory findings, understanding of EG toxicity-specific signs and symptoms, and awareness of other rapid diagnostic tools for EG are essential in clinching the diagnosis. This case highlights the potential atypical presentations of EG toxicity, helpful diagnostic strategies, and the importance of avoiding anchoring bias when commonly associated disease processes are absent.

Evaluation and Management of Hyponatremia in Heart Failure.

PURPOSE OF REVIEW: To provide a contemporary overview of the pathophysiology, evaluation, and treatment of hyponatremia in heart failure (HF). RECENT FINDINGS: Potassium and magnesium losses due to poor nutritional intake and treatment with diuretics cause an intracellular sodium shift in HF that may contribute to hyponatremia. Impaired renal blood flow leading to a lower glomerular filtration rate and increased proximal tubular reabsorption lead to an impaired tubular flux through diluting distal segments of the nephron, compromising electrolyte-free water excretion. Hyponatremia in HF is typically a condition of impaired water excretion by the kidneys on a background of potassium and magnesium depletion. While those cations can and should be easily repleted, further treatment should mainly focus on improving the underlying HF and hemodynamics, while addressing congestion. For decongestive treatment, proximally acting diuretics such as sodium-glucose co-transporter-2 inhibitors, acetazolamide, and loop diuretics are the preferred options.

The prevalence, risk factors and clinical implications of dehydration in older patients: a cross-sectional study.

OBJECTIVES: Adequate hydration is essential for the maintenance of physiological functions. Older adults may not be able to maintain adequate hydration, which is often not recognized. Our aim was to investigate the prevalence, risk factors and clinical implications of dehydration in older adults. METHODS: This cross-sectional study included 964 older adults in one geriatric outpatient clinic in Turkey. Dehydration was defined as a calculated [1,86 × (Na+K)+1,15×glucose+urea +14] plasma osmolarity of ≥ 295 mOsm/L. Clinical characteristics and measures of comprehensive geriatric assessments of patients with dehydration and normohydration were compared. Predictors of dehydration were assessed using logistic regression analysis. RESULTS: Mean age was 79.9 ± 7.7 years, (71.7% female). The prevalence of dehydration was 31%. Female patients, diabetes mellitus (DM), chronic renal failure (CKD), a higher risk of falling (based on Timed Up and Go test), probable sarcopenia, dependence based on basic and instrumental daily living activities (BADL and IADL) were more common in the dehydrated group (p < 0.05). After adjusting for age and gender, dependency on BADL and IADL, the risk of falling were still higher in the dehydrated group (p < 0.05). There were significant relationships between dehydration and risk of falling (OR 1.38, 95% CI 1.00-1.90; p < 0.05), after adjustment for age, gender, DM, CKD. CONCLUSION: Dehydration is common among older adults and is associated with a dependency, probable sarcopenia, and an increased risk of falling. Screening for dehydration and taking preventive measures may be beneficial in avoiding the negative consequences associated with dehydration.

Tear film osmolarity variation between weeks in healthy and dry eye disease subjects / Variação semanal da osmolaridade do filme lacrimal em indivíduos saudáveis e com síndrome do olho seco

ABSTRACT Purpose: The possible variability in diagnostic test results is a statistical feature of dry eye disease patients. The clinician should consider tear film variations over time since the timing of tear film measurements is important for proper diagnosis. The purpose of the present study was to analyze the inter-week variation of osmolarity measurement in healthy and dry eye disease participants. Methods: Based on the Dry Eye Workshop II (DEWS-II) diagnostic methodology report criteria, a battery of tests (Ocular Surface Disease Index [OSDI] questionnaire, breakup time, and corneal staining) was administered to rule out the presence of dry eye disease. A total of 40 qualified volunteers were recruited into two groups: with only 20 healthy and 20 dry eye disease participants. The inter-week variation of osmolarity in the two groups was measured using a TearLab osmometer in two sessions one-week apart. The differences between the results were calculated. Results: There were no significant differences in osmolarity between the two sessions for either the healthy (paired t-test; p=0.085) or dry eye disease (paired t-test; p=0.093) participants. Moreover, there was no significant correlation between the means and differences in either session on healthy (Pearson correlation: r=0.020; p=0.935) or dry eye disease (Pearson correlation: r=-0.022; p=0.928) participants. In session 1, there was a significant difference in osmolarity values between groups (unpaired t-test; p=0.001), but no difference was found in session 2 (unpaired t-test; p=0.292). Conclusions: The present study discovered no inter-week variation in the tear film osmolarity of healthy and dry eye disease participants classified based on the DEWS-II criteria.

RESUMO Objetivo: A possível variabilidade nos resultados de testes diagnósticos é uma característica estatística dos pacientes com síndrome do olho seco. O médico deve considerar as variações do filme lacrimal ao longo do tempo, pois o momento em que o filme lacrimal é medido pode ser crítico para o diagnóstico adequado. O objetivo deste estudo foi analisar a variação semanal da osmolaridade do filme lacrimal em participantes saudáveis e em outros com síndrome do olho seco. Métodos: Com base nos critérios da metodologia de diagnóstico do relatório da Dry Eye Workshop II (DEWSII), foi aplicada uma bateria de testes (questionário do índice de doença da superfície ocular [OSDI], tempo de ruptura do filme lacrimal e coloração da córnea) para descartar a presença de síndrome do olho seco. Um total de 40 voluntários qualificados foi recrutado e distribuído em dois grupos de 20 participantes saudáveis e 20 participantes com síndrome do olho seco. A variação da osmolaridade entre semanas foi medida com um osmômetro TearLab em duas sessões com uma semana de intervalo nos dois grupos. As diferenças entre os resultados foram então calculadas. Resultados: Não foram encontradas diferenças significativas na osmolaridade entre as medidas obtidas nas duas sessões, nem no grupo de participantes saudáveis (teste de t pareado; p=0,085), nem no de participantes com síndrome do olho seco (teste de t pareado; p=0,093). Não foi detectada nenhuma correlação significativa entre as médias e diferenças entre as duas sessões entre participantes saudáveis (correlação de Pearson: r=0,020, p=0,935) e aqueles com síndrome do olho seco (correlação Pearson: r=-0,022, p=0,928). Foi encontrada uma diferença significativa nos valores de osmolaridade entre os dois grupos na primeira sessão (teste de t não pareado; p=0,001), mas nenhuma diferença foi encontrada na segunda sessão (teste de t não pareado; p=0,292). Conclusões: O presente estudo não encontrou variação entre semanas consecutivas na osmolaridade do filme lacrimal em participantes saudáveis e com síndrome do olho seco, classificados com base nos critérios do DEWSII.

First-morning urine osmolality and nocturnal enuresis in children: A single-center prospective cohort study.

PURPOSE: To investigate the treatment outcome of nocturnal enuresis (NE) according to first-morning urine osmolality (Uosm) before treatment. MATERIALS AND METHODS: Ninety-nine children (mean age, 7.2±2.1 y) with NE were enrolled in this retrospective study and divided into two groups according to first-morning Uosm results, that is, into a low Uosm group (<800 mOsm/L; 38 cases, 38.4%) or a high Uosm group (≥800 mOsm/L; 61 cases, 61.6%). Baseline parameters were obtained from frequency volume charts of at least 2 days, uroflowmetry, post-void residual volume, and a questionnaire for the presence of frequency, urgency, and urinary incontinence. Standard urotherapy and pharmacological treatment were administered initially in all cases. Enuresis frequency and response rates were analyzed at around 1 month and 3 months after treatment initiation. RESULTS: The level of first-morning Uosm was 997.1±119.6 mOsm/L in high Uosm group and 600.9±155.9 mOsm/L in low Uosm group (p<0.001), and first-morning voided volume (p=0.021) and total voided volume (p=0.019) were significantly greater in the low Uosm group. Furthermore, a significantly higher percentage of children in the low Uosm group had a response rate of ≥50% (CR or PR) at 1 month (50.0% vs. 24.6%; p=0.010) and 3 months (63.2% vs. 36.1%; p=0.009). CONCLUSIONS: Treatment response rates are higher for children with NE with a lower first-morning Uosm.

Optimizing Mannitol Use in Managing Increased Intracranial Pressure: A Comprehensive Review of Recent Research and Clinical Experiences.

Mannitol, derived from mannose sugar, is crucial in treating patients with elevated intracranial pressure (ICP). Its dehydrating properties at the cellular and tissue levels increase plasma osmotic pressure, which is studied for its potential to reduce ICP through osmotic diuresis. While clinical guidelines support mannitol use in these cases, the best approach for its application continues to be debated. Important aspects needing further investigation include: 1) bolus administration versus continuous infusion, 2) ICP-based dosing versus scheduled bolus, 3) identifying the optimal infusion rate, 4) determining the appropriate dosage, 5) establishing fluid replacement plans for urinary loss, and 6) selecting monitoring techniques and thresholds to assess effectiveness and ensure safety. Due to the lack of adequate high-quality prospective research data, a comprehensive review of recent studies and clinical trials is crucial. This assessment aims to bridge the knowledge gap, improve understanding of effective mannitol use in elevated ICP patients, and provide insights for future research. In conclusion, this review aspires to contribute to the ongoing discourse on mannitol application. By integrating the latest findings, this review will offer valuable insights into the function of mannitol in decreasing ICP, thereby informing better therapeutic approaches and enhancing patient outcomes.

Identification of potentially irritating intravenous medications.

AIMS: To identify commonly used intravenous drugs that may produce endothelial damage. METHODS: An experimental research study was performed using a sample of 62 intravenous drugs commonly used in emergency care, pH and osmolarity were measured. Subsequently, based on these values, the theoretical capacity to cause irritation or endovascular damage was determined and classified as high, moderate, and low. RESULTS: Samples from 19 drugs for fluid therapy, 21 antibiotics and 22 drugs for intravenous use were studied. Glucose solutions, sodium bicarbonate 1M and mannitol 10% showed a high capacity to cause venous irritation. Vancomycin, ciprofloxacin, amiodarone, haloperidol, and labetalol solution presented a high capacity for irritation based on their acidic pH. The antibiotics, dexketoprofen, diazepam, digoxin, etomidate, phenytoin, levetiracetam and metamizole also showed high osmotic values in their reconstituted or undiluted presentations. Moreover, osmolarity of diazepam, digoxin and phenytoin remained high despite being diluted in 100 ml of saline. CONCLUSIONS: Knowing the pH and osmolarity of intravenous drugs allows their capacity to cause endothelial damage to be assessed. The use of comprehensive tables based on the chemical properties of the drugs can be a useful tool to help prevent chemically-induced phlebitis.

Identificación de medicamentos intravenosos potencialmente irritantes / Identification of potentially irritating intravenous medications

Objetivos: Identificar los medicamentos intravenosos de uso común en el ámbito hospitalario con capacidad de producir daño endotelial. Método: Estudio experimental in vitro. La muestra estuvo formada por 62 medicamentos de uso común en los servicios de urgencias y hospitalización. Las variables estudiadas fueron la osmolaridad y el pH. Posteriormente, en base a esos valores, se determinó la capacidad teórica para provocar daño endotelial, clasificándola en alta, moderada y baja. Resultados: Se analizaron 19 medicamentos para fluidoterapia, 21 antibióticos y 22 medicamentos intravenosos. Las soluciones de glucosa, el bicarbonato 1M y el manitol 10% presentaron una capacidad elevada para provocar irritación venosa. Vancomicina, ciprofloxacino, amiodarona, haloperidol y labetalol mostraron una capacidad irritativa elevada derivada de su pH marcadamente ácido. Los antibióticos, dexketoprofeno, diazepam, digoxina, etomidato, fenitoína, levetiracetam y metamizol presentaron valores extremos de osmolaridad en su presentación reconstituida o sin diluir, y mantuvieron sus valores de tonicidad elevados después de diluirlos en 100ml de suero salino el diazepam, la digoxina y la fenitoína. Conclusiones: Conocer el pH y la osmolaridad de los medicamentos intravenosos permite evaluar su capacidad para provocar daño endotelial. La creación de tablas comprensivas en base a las propiedades químicas de los medicamentos puede constituir una herramienta útil que contribuya a prevenir la flebitis químicamente inducida.(AU)

Aims: To identify commonly used intravenous drugs that may produce endothelial damage. Methods: An experimental research study was performed using a sample of 62 intravenous drugs commonly used in emergency care, pH and osmolarity were measured. Subsequently, based on these values, the theoretical capacity to cause irritation or endovascular damage was determined and classified as high, moderate, and low. Results: Samples from 19 drugs for fluid therapy, 21 antibiotics and 22 drugs for intravenous use were studied. Glucose solutions, sodium bicarbonate 1M and mannitol 10% showed a high capacity to cause venous irritation. Vancomycin, ciprofloxacin, amiodarone, haloperidol, and labetalol solution presented a high capacity for irritation based on their acidic pH. The antibiotics, dexketoprofen, diazepam, digoxin, etomidate, phenytoin, levetiracetam and metamizole also showed high osmotic values in their reconstituted or undiluted presentations. Moreover, osmolarity of diazepam, digoxin and phenytoin remained high despite being diluted in 100mL of saline. Conclusions: Knowing the pH and osmolarity of intravenous drugs allows their capacity to cause endothelial damage to be assessed. The use of comprehensive tables based on the chemical properties of the drugs can be a useful tool to help prevent chemically-induced phlebitis.(AU)

The Contribution of Plasma Urea to Total Osmolality During Iatrogenic Fluid Reduction in Critically Ill Patients.

Hyperosmolality is common in critically ill patients during body fluid volume reduction. It is unknown whether this is only a result of decreased total body water or an active osmole-producing mechanism similar to that found in aestivating animals, where muscle degradation increases urea levels to preserve water. We hypothesized that fluid volume reduction in critically ill patients contributes to a shift from ionic to organic osmolytes similar to mechanisms of aestivation. We performed a post-hoc analysis on data from a multicenter observational study in adult intensive care unit (ICU) patients in the postresuscitative phase. Fluid, electrolyte, energy and nitrogen intake, fluid loss, estimated glomerular filtration rate (eGFR), and estimated plasma osmolality (eOSM) were registered. Contributions of osmolytes Na+, K+, urea, and glucose to eOSM expressed as proportions of eOSM were calculated. A total of 241 patients were included. eOSM increased (median change 7.4 mOsm/kg [IQR-1.9-18]) during the study. Sodium's and potassium's proportions of eOSM decreased (P < .05 and P < .01, respectively), whereas urea's proportion increased (P < .001). The urea's proportion of eOSM was higher in patients with negative vs. positive fluid balance. Urea's proportion of eOSM increased with eOSM (r = 0.63; adjusted for eGFR r = 0.80), but not nitrogen intake. In patients without furosemide and/or renal replacement therapy (n = 17), urea's proportion of eOSM and eOSM correlated strongly (r = 0.92). Urea's proportion of eOSM was higher in patients not surviving up to 90 d. In stabilized ICU patients, the contribution of urea to plasma osmolality increased during body water volume reduction, statistically independently of nitrogen administration and eGFR. The shift from ionic osmolytes to urea during body fluid volume reduction is similar to that seen in aestivating animals. ClinicalTrials.org Identifier: NCT03972475.

Management of severe inaugural diabetic ketoacidosis in paediatric intensive care: retrospective comparison of two protocols.

The best protocol for severe inaugural diabetic ketoacidosis (DKA) in children remains unclear. We compared two protocols by assessing effects during the first 24 h on osmolality, serum sodium, and glucose variations, which are associated with the risk of cerebral oedema, the most dreaded complication of DKA. We also recorded complications. We retrospectively included children aged 28 days to 18 years and admitted for severe DKA to either of two paediatric intensive care units (PICUs) in Paris (France). The two protocols differed regarding hydration volume, glucose intake, and sodium intake. From 17 June 2010 to 17 June 2015, 93 patients were included, 29 at one PICU, and 64 at the other. We compared severe glycaemic drops (> 5.5 mmol/L/h), mean glycaemia variations, serum sodium, serum osmolality, and the occurrence of cerebral oedema (CE) during the first 24 h after PICU admission. Severe glycaemic drops occurred in 70% of patients, with no between-group difference. Blood glucose, serum sodium, and serum osmolality variations were comparable. Seven (7.5%) patients were treated for suspected CE, (4 [10.3%)] and 3 [6.3%]) in each PICU; none had major residual impairments. CONCLUSION:  The two paediatric DKA-management protocols differing in terms of fluid-volume, glucose, and sodium intakes had comparable effects on clinical and laboratory-test changes within 24 h. Major drops in glycaemia and osmolality were common with both protocols. No patients had residual neurological impairments. WHAT IS KNOWN: • Cerebral oedema is the most severe complication of diabteic ketoacidosis in children.The risk of cerebral oedema is dependant on both patient related and treatment-related factors. • The optimal protocol for managing severe inaugural diabetic ketoacidosis in children remains unclear, and few studies have targeted this specific population. WHAT IS NEW: • Two management protocols that complied with ISPAD guidelines but differed regarding the amounts of fluids, glucose, and sodium administered produced similar outcomes in children with severe inaugural diabetic ketoacidosis. • Cerebral oedema was rare with both protocols and caused no lasting impairments.

Neuronal Swelling: A Non-osmotic Consequence of Spreading Depolarization.

An acute reduction in plasma osmolality causes rapid uptake of water by astrocytes but not by neurons, whereas both cell types swell as a consequence of lost blood flow (ischemia). Either hypoosmolality or ischemia can displace the brain downwards, potentially causing death. However, these disorders are fundamentally different at the cellular level. Astrocytes osmotically swell or shrink because they express functional water channels (aquaporins), whereas neurons lack functional aquaporins and thus maintain their volume. Yet both neurons and astrocytes immediately swell when blood flow to the brain is compromised (cytotoxic edema) as following stroke onset, sudden cardiac arrest, or traumatic brain injury. In each situation, neuronal swelling is the direct result of spreading depolarization (SD) generated when the ATP-dependent sodium/potassium ATPase (the Na+/K+ pump) is compromised. The simple, and incorrect, textbook explanation for neuronal swelling is that increased Na+ influx passively draws Cl- into the cell, with water following by osmosis via some unknown conduit. We first review the strong evidence that mammalian neurons resist volume change during acute osmotic stress. We then contrast this with their dramatic swelling during ischemia. Counter-intuitively, recent research argues that ischemic swelling of neurons is non-osmotic, involving ion/water cotransporters as well as at least one known amino acid water pump. While incompletely understood, these mechanisms argue against the dogma that neuronal swelling involves water uptake driven by an osmotic gradient with aquaporins as the conduit. Promoting clinical recovery from neuronal cytotoxic edema evoked by spreading depolarizations requires a far better understanding of molecular water pumps and ion/water cotransporters that act to rebalance water shifts during brain ischemia.

Re-evaluating Safe Osmolarity for Peripheral Parenteral Nutrition in Neonatal Intensive Care Patients.

OBJECTIVE: To reach nutrition goals for neonatal patients, institutions often exceed the American Society for Parenteral and Enteral Nutrition recommended maximum of 900 mOsm/L for peripheral parenteral nutrition (PPN). Evidence is limited regarding the safety of PPN osmolarities above this maximum, specifically in neonatal patients. The purpose of this study was to determine if PPN with osmolarities ≥ 1000 mOsm/L is associated with an increased rate of line-related complications. METHODS: This retrospective study included infants admitted to the Penn State Health Children's Hospital NICU from January 1, 2013, through July 31, 2018, who were receiving PPN, to assess if solutions with osmolarities ≥ 1000 mOsm/L versus < 1000 mOsm/L are associated with increased rates of line-related complications. RESULTS: A total of 200 patients were included in the study, and 618 individual PPN days were analyzed. Baseline patient characteristics were similar between groups. The PPN osmolarities ranged from 610 to 1267 mOsm/L. Overall, the incidence of line-related complications for PPN < 1000 (n = 342 PPN days) and ≥ 1000 mOsm/L (n = 276 PPN days) was 28.9% and 29.0%, respectively (OR 1.00 [95% CI 0.72-1.40, p = 0.99]). Irrespective of PPN osmolarity, infants weighing > 1.5 kg had significantly greater odds of experiencing line complications compared with patients < 1 kg, but showed no difference compared with patients weighing 1 to 1.5 kg. CONCLUSIONS AND RECOMMENDATIONS: There were no significant differences in the incidence of line-related complications in NICU patients receiving PPN with osmolarities 1000 to 1250 versus < 1000 mOsm/L.

Postoperative Copeptin as a Biomarker for Development of Diabetes Insipidus Following Hypothalamic-Pituitary Surgery.

OBJECTIVE: Copeptin is a surrogate marker of arginine vasopressin release with better stability and simplicity of measurement. Postoperative copeptin levels may guide clinicians in stratifying patients who need close monitoring of fluid balance. The objective is to determine whether copeptin is a predictive marker of postoperative diabetes insipidus (DI). METHODS: This is a prospective diagnostic study. Patients who underwent neurosurgical intervention of the sellar-suprasellar regions were recruited. Serum copeptin levels were measured before and after surgery, within 24 hours. Logistic regression analysis and diagnostic performance measures were calculated to determine the relationship between postoperative copeptin levels and DI. RESULTS: Of 82 patients, 26 (31.7%) developed postoperative DI, with 7 patients (8.5%) having permanent DI. The samples for copeptin measurement were taken at 13 ± 2.1 hours postoperatively. From the receiver operating characteristic analysis, low postoperative copeptin levels (<2.5 pmol/L) demonstrated an acceptable ability to predict DI (area under the curve, 0.72; 95% CI, 0.60-0.84). Discriminative power was stronger in the permanent DI group (area under the curve, 0.82; 95% CI, 0.64-1.00). Postoperative copeptin levels <2.5 pmol/L were associated with DI (specificity > 91%). However, postoperative copeptin levels >20 pmol/L were rarely associated with DI, with a negative predictive value of 100%. CONCLUSIONS: In patients undergoing sellar-suprasellar interventions, low postoperative copeptin levels within the first postoperative day predict postoperative DI, whereas high levels exclude it. Copeptin measurement should be applied in the clinical practice of postoperative care in patients following hypothalamic-pituitary surgery. This study may expand the potential use of copeptin, including in the Asian population.

Quality Assurance in Lactation: Reliability of OM-6050 Station System to Test Mother's Milk Osmolality.

BACKGROUND: Mother's own milk does not provide enough nutrients to feed a preterm baby born before 32 weeks' gestation; therefore, human milk fortifiers are needed. However, human milk fortifiers increase the osmolality, and enteral administration of high osmolality fluids has been associated with gastrointestinal symptoms. For this reason, it is necessary for laboratories to have a validated system in order to measure human milk osmolality. RESEARCH AIM: The aim of this study was to validate the OM-6050 Station System for measuring the osmolality of fortified mother's milk samples. METHODS: Osmolality was measured using the osmometer OM-6050 Station System. Milk samples from healthy mothers (N = 3) unfortified and with two fortifiers (Almirón Fortifier® or NAN FM85®), as well as a nutritional supplement (Duocal MCT®) were used in the validation study through precision and linearity analysis. RESULTS: In the precision study the mean intra-assay coefficient of variation was 1.2% and 1.7% for mother's milk and fortified mother's milk, respectively. The mean inter-assay coefficient of variation was ≤ 1% in both cases. In the linearity study the regression analysis had a linear response to fortified mother's milk osmolality between 294 mOsm/kg and 539 mOsm/kg. CONCLUSION: The osmometer OM-6050 Station was reliable for determining the osmolality of fortified and unfortified mother's milk. It may be useful in the clinical practices within Neonatal Intensive Care Units.

Hipertensão ocular recorrente durante hemodiálise em paciente portador de glaucoma / Recurrent intraocular hypertension during hemodialysis in glaucoma patient

RESUMO A hipertensão ocular aguda durante a hemodiálise constitui evento raro e pode ser causa relevante de interrupção do tratamento dialítico devido à dor. Relata-se o caso de um paciente de 70 anos de idade, do sexo masculino, que apresentou quadros recorrentes de intensa dor ocular unilateral durante sessões dialíticas devido ao aumento de pressão intraocular. O paciente era portador de grave diminuição da acuidade visual no olho direito devido a glaucoma neovascular, controlado com medicação hipotensora tópica. Uma hora após o início da sessão dialítica, apresentou dor excruciante no olho direito, sendo necessário interromper o tratamento por diversas vezes. A dor somente era amenizada com uso de opioides por via endovenosa ou após cerca de 6 horas do procedimento. Injeção intraocular de drogas antiangiogênicas e acetazolamida por via oral, assim como tratamentos tradicionais para quadros agudos de hipertensão intraocular, como uso de hipotensor tópico e medicamentos hiperosmolares, foram insuficientes para o controle da dor. O problema se resolveu com ciclofotocoagulação transescleral realizada com laser diodo, com redução da pressão intraocular basal e controle da dor, o que permitiu a realização de sessões completas de hemodiálise. A base fisiopatológica desse evento incomum e suas opções terapêuticas são discutidas aqui.

ABSTRACT Acute ocular hypertension during hemodialysis is a rare event and may lead to interruption of dialytic therapy due to pain. A case of a 70-year-old male patient is reported, who presented recurrent intense unilateral ocular pain episodes during dialysis sessions for increased intraocular pressure. The patient presented with severely decreased visual acuity in the right eye due to neovascular glaucoma, which was controlled with topical hypotensive medication. One hour after initiating dialysis, he presented an excruciating pain on the right eye, which required interruption of treatment several times. Pain relief was possible only with intravenous opioids, or approximately 6 hours after dialysis. Intraocular injection of antiangiogenic drugs and per oris acetazolamide, as well as other traditional treatments for acute episodes of intraocular hypertension, such as topical antihypertensive agents and hyperosmotic medications, were not sufficient to control pain. The problem was solved with transscleral diode laser cyclophotocoagulation, which reduced baseline intraocular pressure and controlled pain, enabling complete hemodialysis sessions. The pathophysiological aspects and therapeutic options of this unusual condition are discussed.

Effects of the ice popsicle on vasopressin, osmolality, thirst intensity, and thirst discomfort / Efectos del picolé de hielo sobre vasopresina, osmolaridad, intensidad y malestar de la sed / Efeitos do picolé de gelo sobre vasopressina, osmolaridade, intensidade e desconforto da sede

ABSTRACT Objective: To analyze the effects of the ice popsicle on vasopressin, osmolality, thirst intensity, and thirst discomfort. Method: This is a quasi-experimental, pre- and post-test study conducted in a laboratory. The sample consisted of nine healthy male volunteers, who received 2% hypertonic saline solution. Results: Popsicle intake did not result in a statistically significant reduction in vasopressin levels (F=0.876 and p=0.428). However, there was a reduction in the hormonal physiological profile of vasopressin from 7.1 pg/ml to 5.8 pg/ml after the first two interventions. Osmolality concentration changed from 270.65 to 286.51 mOsm/kg, with no statistical difference (F=2.207; p=0.09). Ice popsicles significantly reduced thirst intensity (F=10.00; p=0.001) and thirst discomfort (F=10.528; p <0.001). Conclusion: There was a reduction in thirst intensity and discomfort after the use of the 20 ml ice popsicle. There was no statistical difference for vasopressin and osmolality. However, there was a reduction in the hormonal physiological profile of vasopressin during 30 minutes of intervention.

RESUMEN Objetivo: Evaluar los efectos del picolé de hielo sobre el perfil hormonal de la vasopresina, la osmolaridad, y la intensidad y el malestar de la sed. Método: Estudio casi-experimental pre- y pos-test, realizado en laboratorio. Nueve varones voluntarios sanos recibieron solución salina endovenosa al 2% y un picolé de hielo de 20 ml cada 15 minutos. Resultados: Ingerir el picolé no derivó en una caída estadísticamente significativa del nivel de vasopresina (F=0,876 y p=0,428). Entretanto, se registró una reducción en el perfil hormonal de la vasopresina de 7,1 pg/ml a 5,8 pg/ml después de las dos intervenciones. La osmolaridad plasmática se modificó de 270,65 a 286,51 mOsm/kg sin diferencia estadística (F=2,207; p=0,09). Se registraron reducciones en la intensidad (F=10,00 y p= 0,001) y en el malestar de la sed (F= 10,528; p<0,001). Conclusión: Se registraron reducciones en la intensidad y el malestar de la sed después de la intervención. No hubo diferencia estadística para la vasopresina y la osmolaridad. De esta manera, se observa la reducción en el perfil fisiológico de la vasopresina durante los 30 minutos de la intervención.

RESUMO Objetivo: Avaliar efeitos do picolé de gelo sobre perfil hormonal de vasopressina, osmolaridade, intensidade e desconforto da sede. Método: Quase-experimental, pré e pós-teste, realizado em laboratório. Nove voluntários saudáveis receberam solução salina endovenosa 2% e um picolé de gelo 20 ml a cada 15 minutos. As variáveis foram coletadas em cinco momentos. Resultados: Ingestão do picolé não resultou queda estatisticamente significativa da vasopressina (F = 0,876 e p = 0,428). Houve redução no perfil hormonal da vasopressina de 7,1 pg/ml para 5,8 pg/ml após duas intervenções. Osmolaridade plasmática alterou de 270,65 para 286,51 mOsm/kg, sem diferença estatística (F=2,207; p= 0,09). Houve redução da intensidade (F=10,00 e p= 0,001) e desconforto da sede (F=10,528; p < 0,001). Conclusão: Houve redução na intensidade e desconforto da sede. Não houve diferença estatística para vasopressina e osmolaridade. Observou-se redução no perfil fisiológico da vasopressina durante 30 minutos de intervenção.

Seasonal variation in hydration status among community-dwelling elderly in Japan.

AIM: While the heat during the summer season may dehydrate the elderly, little is known about the seasonal variation in dehydration. This study aimed to investigate the seasonal variation in hydration status among the community-dwelling elderly in Japan. METHODS: We retrospectively analyzed the data collected after an overnight fast of adults aged ≥65 years who had no advanced kidney disease and underwent an annual health checkup at Nihon University Hospital between January and December 2019. Participants were classified according to their checkup date, whether summer (n = 265) or not summer (n = 638). The not summer group was subdivided into spring (n = 235), autumn (n = 213) and winter (n = 190). RESULTS: Among the four seasons, the spring group showed the highest levels of plasma osmolality (306.1 ± 3.9 mOsm/L), urine specific gravity (1.0172 ± 0.0058) and prevalence rates of urine specific gravity ≥1.020 (34.0%). However, seasonal differences were clinically mild, and >90% of participants showed plasma osmolality ≥300 mOsm/L, indicating dehydration, in all four seasons. The summer group showed lower urine specific gravity levels (1.0150 ± 0.0062 vs. 1.0165 ± 0.0064, P < 0.001) and prevalence rates of urine specific gravity ≥1.020 (22.6% vs. 30.4%, P = 0.023) than did the not summer group. The summer season was associated with low urine specific gravity levels even after adjusting for the multiple linear regression model. CONCLUSION: Japanese elderly after overnight fast are more dehydrated during the spring rather than the summer. Geriatr Gerontol Int 2020; 20: 904-910.

A Simple Predictive Factor for Mortality in Fontan Surgery: Serum Hypo-Osmolality.

OBJECTIVE: Close follow-up is important after the Fontan procedure, which is a palliative surgical method for a single ventricle. In this period, serum osmolality is an important parameter with the advantages of easy to obtain and poor outcome prediction. METHODS: Patients who had undergone Fontan operation between May 2011 and February 2017 were retrospectively evaluated. Patients were divided into three groups based on their serum osmolality values: hypoosmolar (Group 1), isosmolar (Group 2), and hyperosmolar (Group 3). Demographics, clinical information and postoperative data of the groups were compared. RESULTS: Forty-three patients had undergone extracardiac Fontan operation in the study period. There were 8, 19 and 16 patients in Groups 1, 2 and 3, respectively. Among the three groups, postoperative intubation and length of hospital stay, prolonged pleural effusion, need for inotropic support and mortality were statistically significantly higher in Group 1. CONCLUSION: After the Fontan procedure, one of the determinants of cardiac output might be affected by serum osmolality. Decreased serum osmolality might be associated with poor prognosis after Fontan procedure. Serum osmolality monitoring may be beneficial to improve postoperative outcomes in these patients.

Pharmacokinetic profiles of levofloxacin after intravenous, intramuscular and subcutaneous administration to rabbits (Oryctolagus cuniculus).

Levofloxacin pharmacokinetic profiles were evaluated in 6 healthy female rabbits after intravenous (I/V), intramuscular (I/M), or subcutaneous (S/C) administration routes at a single dose of 5 mg/kg in a 3 × 3 cross-over study. Plasma levofloxacin concentrations were detected using a validated Ultra Performance Liquid Chromatography method with a fluorescence detector. Levofloxacin was quantifiable up to 10 h post-drug administration. Mean AUC0-last values of 9.03 ± 2.66, 9.07 ± 1.80, and 9.28 ± 1.56 mg/h*L were obtained via I/V, I/M, and S/C, respectively. Plasma clearance was 0.6 mL/g*h after I/V administration. Peak plasma concentrations using the I/M and S/C routes were 3.33 ± 0.39 and 2.91 ± 0.56 µg/mL. Bioavailability values, after extravascular administration were complete, - 105% ± 27% (I/M) and 118% ± 40% (S/C). Average extraction ratio of levofloxacin after I/V administration was 7%. Additionally, levofloxacin administration effects on tear production and osmolarity were evaluated. Tear osmolarity decreased within 48 h post-drug administration. All 3 levofloxacin administration routes produced similar pharmacokinetic profiles. The studied dose is unlikely to be effective in rabbits; however, it was calculated that a daily dose of 29 mg/kg appears effective for I/V administration for pathogens with MIC < 0.5 µg/mL.