Effect of sodium-chloride ion difference on pH regulation.

BACKGROUND: In the Stewart approach, the difference between the cation and anion concentrations, especially between sodium, accounting for the majority of cations, and chloride, comprising the majority of anions, is an important factor in pH regulation. This study investigated the effect of sodium-chloride ion difference (SCD) on pH regulation comparing with those of PaCO2 and lactate. METHODS: Arterial blood gas samples measured at our pediatric intensive care unit of a tertiary children's hospital between January and June 2020 were included. Samples that met the following criteria were excluded: samples collected from patients taking potassium bromide and samples with lactate concentration of >25 mmol/L. From the eligible data, pH was chosen as the dependent variable and SCD, lactate, and PaCO2 as independent variables, and then, a multiple regression analysis was performed. RESULTS: In total, 5360 samples were included. Of these, five samples were excluded according to the exclusion criteria. Finally, 5355 samples were analyzed. As the variance inflation factors were <2.0 for all three variables, there was no multicollinearity. The following model was derived: pH = 7.384 + [0.97 × SCD (mEq/L) - 0.66 × PaCO2 (mmHg) - 1.33 × Lac (mmol/L)] × 10-2 (adjusted R-squared = 0.73; P value < 0.001). Based on the standardized partial regression coefficients (ß), pH was affected in the order of PaCO2 (ßPaCO2 = -0.95), SCD (ßSCD = 0.72), and lactate (ßlactate = -0.33). CONCLUSIONS: The prevention of SCD reduction, together with respiratory and metabolic management, is important for pH regulation.

Enteral electrolytic solutions administered in continuous flow via naso-ruminal route in adult goats.

This study aimed to investigate the effects of maintenance enteral electrolytic solutions administered naso-ruminally in continuous flow in adult goats subjected to water and food restriction. Six adult non-pregnant and non-lactating female goats, aged between two and five years old, were used in a crossover (6 × 2) study. Solution 1 (SEE1) comprised: 4.5 g sodium chloride (NaCl); 1 g potassium chloride (KCl); 0.5 g magnesium chloride (MgCl); 1 g calcium chloride in 1,000 ml of water (measured osmolarity: 202 mOsm/l). Solution 2 (SEE2) comprised: 4.5 g of NaCl; 1 g of KCl; 0.5 g of MgCl; 2 g of calcium acetate in 1,000 ml of water (measured osmolarity: 212 mOsm/l). The solutions were administered naso-ruminally at a dose rate of 15 ml/kg/hr, for 12 hr. The animals were evaluated at times T-24, T0, T4, T8, T12, and T24. Both enteral electrolytic solutions were effective in expanding blood volume. SEE1 showed a low-intensity acidifying potential, while SEE2 showed behavior of a neutral enteral electrolytic solution.

Hypopituitarism manifesting after invasive dental treatment in a patient with carcinoma of the tongue: a case report.

BACKGROUND: The symptoms of hypopituitarism are not usually discussed in the clinical setting of oral surgery. CASE PRESENTATION: We herein report a case of hypopituitarism that became evident after biopsy and extraction of several teeth in a 68-year-old man with tongue cancer. Three days after biopsy, the patient developed nausea and vomiting, and his serum sodium had fallen to 124 mEq/L. His serum cortisol concentration was low. Although the plasma concentration of adrenocorticotropic hormone (ACTH) was within the normal range, ACTH stimulation testing showed a lack of cortisol response. Given these findings, we suspected secondary adrenal insufficiency. To investigate the cause of secondary adrenal insufficiency, MRI of the head was performed, which revealed pituitary gland atrophy. The results of pituitary anterior lobe hormone-stimulation tests were compatible with hypopituitarism. Thirty days after biopsy, partial tongue resection was successfully performed under general anesthesia with perioperative hydrocortisone supplementation. CONCLUSIONS: We must be aware of various signs of hypopituitarism when we perform invasive dental treatment.

The Predictive Value of Salt Sensitivity and Osmotic Fragility in the Development of Cerebral Small Vessel Disease.

Increased salt intake in food probably affects the progression of cerebral small vessel disease (CSVD), which justifies the study of disturbances in sodium homeostasis associated with the development of CSVD. We aimed to clarify the role of salt sensitivity and osmotic fragility in the development of CSVD. Erythrocyte salt sensitivity was measured using the modified salt blood test, and osmotic fragility was measured using the classic osmotic fragility test in 73 patients with CSVD (48 women; 60.1 ± 6.5 years) and 19 healthy volunteers (14 women; 56.9 ± 6.4 years). Salt sensitivity and osmotic fragility exhibited a predictive value in relation to CSVD. These parameters were associated with an increase in white matter hyperintensities (P = 0.019 and 0.004, respectively). Their simultaneous use increased their predictive ability for CSVD (P < 0.000001; AUC (95% CI), 0.824 (0.724-0.923)). The possibility of predicting CSVD using erythrocyte salt sensitivity and osmotic fragility indicates the value of the individual glycocalyx buffer capacity in relation to sodium and the activity of sodium channels in the development of CSVD. Increased salt sensitivity and osmotic fragility seem to be risk factors for CSVD.

Assessment of Acute Kidney Injury in Neurologically Injured Patients Receiving Hypertonic Sodium Chloride: Does Chloride Load Matter?

Background: Increasing evidence suggests that large-volume infusions of 0.9% sodium chloride (NaCl) for resuscitation are associated with hyperchloremic metabolic acidosis, renal vasoconstriction, and increased risk of acute kidney injury (AKI). Patients with neurological injury may require hypertonic NaCl for therapeutic hypernatremia, treatment of cerebral salt wasting, hyponatremia, or elevated intracranial pressure. Consequently, this increased exposure to chloride may result in an increased risk for development of AKI. Objective: The primary aim of this study was to describe the risk for development of AKI in neurologically injured patients receiving large volumes of intravenous hypertonic NaCl. Methods: This single-center, retrospective study looked at neurologically injured patients who received hypertonic NaCl and sodium acetate. Data were collected to assess renal function, hyperchloremia, and acidemia. Receiver operating characteristic (ROC) curve analysis was used to determine the predictive association between the amount of daily and overall chloride exposure and development of AKI. Results: A total of 301 patients were screened, and of those, 142 were included. Of the 142 patients included, 13% developed AKI, and 38% developed hyperchloremia. Additionally, 32% of patients were switched from NaCl to sodium acetate after an average of 3.4 ± 1.5 days of NaCl therapy. The ROC curve demonstrated that if patients received greater than 2055 mEq of chloride over 7 days, they were more likely to develop AKI (sensitivity 72%, specificity 70%; P = 0.002; area under the curve = 0.7). Conclusion and Relevance: Neurologically injured patients receiving hypertonic sodium therapy with a high chloride load are at risk of developing hyperchloremia and AKI.

Transcriptome Sequencing to Detect the Potential Role of Long Noncoding RNAs in Salt-Sensitive Hypertensive Rats.

BACKGROUNDS: Long noncoding RNAs (lncRNAs) play an important role in various biological processes. However, their functions in salt-sensitive hypertension are largely unknown. In this study, the lncRNA-seq technique was employed to compare the expression profiles of lncRNAs and mRNAs in salt-sensitive hypertensive rats. METHODS: Blood pressure, serum sodium, and urinary creatinine were texted in salt-sensitive and salt-insensitive rats fed with different salt concentrations. High-throughput sequencing was used to detect the expression of lncRNAs and mRNA in the renal medulla of the two groups. RESULTS: Blood pressure and urinary sodium/creatinine of high-salt diets of the sensitive group were significantly higher than that in the control group. Serum sodium has no significant difference between the two groups in high-salt diets. NONRATG007131.2 and NONRATG012674.2 were the most different lncRNAs in the high salt-sensitive group. Correlation analysis reveals that Matn1, Serpinb12, Anxa8, and Hspa5 may play an important role in salt-sensitive hypertension. CONCLUSION: This study analyzed the difference in lncRNA and mRNA between salt-sensitive and salt-insensitive rats with different salt diets by high-throughput sequencing. Salt sensitivity and salt concentration were two key factors for the induction of hypertension. We found some potential genes that play an important role in salt-sensitive hypertension.

Association of Preoperative Serum Chloride Levels With Mortality and Morbidity After Noncardiac Surgery: A Retrospective Cohort Study.

BACKGROUND: Postoperative hyperchloremia is known to be related to increases in mortality and morbidity after surgery. However, the relationship between preoperative hyperchloremia and hypochloremia and postoperative mortality and morbidity is not well established. Our aim was to evaluate the relationship between preoperative hyperchloremia or hypochloremia, as assessed using preoperative serum chloride tests, and 90-day mortality and morbidity after noncardiac surgery. METHODS: In this retrospective cohort study, we reviewed the medical records of patients >20 years of age who underwent noncardiac surgery between January 2010 and December 2016. Patients were categorized into one of the following groups on the basis of the results of serum chloride testing performed within 1 month before surgery: normochloremia, 97-110 mmol·L; hyperchloremia, >110 mmol·L; and hypochloremia, <97 mmol·L. The primary end point of this study was the difference in postoperative 90-day mortality among the preoperative serum chloride groups. The secondary end point was the difference in postoperative acute kidney injury incidence among the preoperative serum chloride groups. RESULTS: A total of 106,505 patients were included in the final analysis (2147 were allocated to the preoperative hypochloremia group and 617 to the hyperchloremia group). Multivariable Cox regression analysis revealed significantly increased 90-day mortality in the hypochloremia (hazard ratio, 1.46; 95% CI, 1.16-1.84; P = .001) and hyperchloremia (hazard ratio, 1.76; 95% CI, 1.13-2.73; P = .013) groups when compared with the normochloremia group. In addition, multivariable logistic regression analysis revealed a 1.83-fold increased odds of acute kidney injury in the preoperative hypochloremia group when compared with the normochloremia group (odds ratio, 1.83; 95% CI, 1.53-2.19; P < .001). CONCLUSIONS: Preoperative hypochloremia and hyperchloremia were related to increased 90-day mortality after noncardiac surgery. In addition, preoperative hypochloremia was related to an increased risk for postoperative acute kidney injury.

Microfluidic Microwave Sensor for Detecting Saline in Biological Range.

A device for measuring biological small volume liquid samples in real time is appealing. One way to achieve this is by using a microwave sensor based on reflection measurement. A prototype sensor was manufactured from low cost printed circuit board (PCB) combined with a microfluidic channel made of polymethylsiloxane (PDMS). Such a sensor was simulated, manufactured, and tested including a vacuum powered sample delivery system with robust fluidic ports. The sensor had a broad frequency band from 150 kHz to 6 GHz with three resonance frequencies applied in sensing. As a proof of concept, the sensor was able to detect a NaCl content of 125 to 155 mmol in water, which is the typical concentration in healthy human blood plasma.

Association between serum Na-Cl level and renal function decline in chronic kidney disease: results from the chronic kidney disease Japan cohort (CKD-JAC) study.

BACKGROUND: Metabolic acidosis, which reduces serum bicarbonate levels, contributes to the progression of chronic kidney disease (CKD). The difference between sodium and chloride (Na-Cl) may theoretically predict serum bicarbonate levels. This study aimed to evaluate serum Na-Cl level as a risk factor for renal function decline among patients who participated in the chronic kidney disease Japan cohort (CKD-JAC) study. METHODS: The association between low Na-Cl concentration (< 34 mmol/L) and composite renal function decline events (any initiation of renal replacement therapy or 50% decline in estimated glomerular filtration rate) was evaluated among 2143 patients with CKD stage G3a-4. Using Cox regression analysis, hazard ratios (HRs) were estimated after adjusting for the following covariates: age, sex, diabetes mellitus, diabetic nephropathy, cardiovascular disease, anemia, angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists, loop diuretics, cigarette smoking, body mass index, serum albumin, systolic blood pressure, urine albumin-to-creatinine ratio, and CKD stage. RESULTS: Composite renal function decline events were observed in 405 patients (18.9%) over the 4-year follow-up period. Low serum Na-Cl level (< 34 mmol/L) was independently associated with a greater risk for composite renal function decline events (HR 1.384; 95% confidence interval [CI], 1.116-1.717). Subgroup analyses identified that the association between low Na-Cl level and composite renal function decline events was stronger among patients with CKD stage G4 and those with anemia. CONCLUSIONS: Our investigation suggests that Na-Cl is an independent predictor of CKD progression, especially among patients with CKD stage G4 and those with anemia.

Hyperchloremia and postoperative acute kidney injury: a retrospective analysis of data from the surgical intensive care unit.

BACKGROUND: Whether perioperative hyperchloremia can induce postoperative acute kidney injury (AKI) is controversial. We investigated the association between perioperative hyperchloremia and postoperative AKI in patients admitted to the intensive care unit (ICU) after surgery. METHODS: We performed a retrospective observational study of patients admitted to the surgical ICU at a single tertiary care hospital between January 2011 and June 2016. Our primary objective was to determine whether hyperchloremia or an increase in serum chloride levels was associated with postoperative AKI. Perioperative hyperchloremia was defined as serum chloride levels ≥ 110 mmol·L- 1 during postoperative days (PODs) 0-3. The increase in serum chloride levels was defined as the difference between preoperative and maximum postoperative serum chloride levels during the first 3 days after surgery. RESULTS: Of the 7991 patients included in the final analysis, 1876 (23.5%) developed hyperchloremia during PODs 0-3, and 1187 (14.9%) developed postoperative AKI. Exposure to hyperchloremia during the first 3 days after surgery was not associated with postoperative AKI (odds ratio, 1.09; 95% confidence interval, 0.80-1.49; P = 0.571). However, among patients with preoperative chronic kidney disease stage ≥ 3 (estimated glomerular filtration rate < 60 mL·min- 1·1.73·m- 2), the incidence of postoperative AKI was higher in patients with an increase > 6 mmol·L- 1 in serum chloride levels than in patients with an increase ≤ 1 mmol·L- 1 (odds ratio, 1.42; 95% confidence interval, 1.09-1.84; P = 0.009). In addition, the incidence of postoperative AKI stage ≥ 2 was not associated with exposure to hyperchloremia or with the increase in serum chloride levels during PODs 0-3, regardless of preoperative kidney function. CONCLUSIONS: Exposure to perioperative hyperchloremia is not associated with postoperative AKI in surgical ICU patients. However, in patients with moderate-to-severe chronic kidney disease (stage ≥ 3), a substantial perioperative increase in serum chloride levels may reflect a higher risk of AKI.

A Controlled Increase in Dietary Phosphate Elevates BP in Healthy Human Subjects.

Background Despite epidemiologic evidence for increased cardiovascular morbidity and mortality associated with both high dietary and serum phosphate in humans with normal renal function, no controlled phosphate intervention studies of systemic hemodynamics have been reported. Higher serum 25(OH) vitamin D levels are associated with better cardiovascular outcomes, but vitamin D increases intestinal phosphate absorption.Methods We conducted a prospective outpatient study with blinded assessment in 20 young adults with normal renal function randomized to high phosphate (regular diet plus 1 mmol/kg body wt per day of Na as neutral sodium phosphate) or low phosphate (regular diet plus lanthanum, 750 mg thrice/day, plus 0.7 mmol/kg body wt per day of Na as NaCl) for 11 weeks. After 6 weeks, all subjects received vitamin D3 (600,000 U) by intramuscular injection. Outcome parameters were 24-hour ambulatory systolic and diastolic BP (SBP and DBP), pulse rate (PR), biomarkers, and measures of endothelial and arterial function.Results Compared with the low-phosphate diet group, the high-phosphate diet group had a significant increase in mean±SEM fasting plasma phosphate concentration (0.23±0.11 mmol/L); 24-hour SBP and DBP (+4.1; 95% confidence interval [95% CI], 2.1 to 6.1; and +3.2; 95% CI, 1.2 to 5.2 mm Hg, respectively); mean 24-hour PR (+4.0; 95% CI, 2.0 to 6.0 beats/min); and urinary metanephrine and normetanephrine excretion (54; 95% CI, 50 to 70; and 122; 95% CI, 85 to 159 µg/24 hr, respectively). Vitamin D had no effect on any of these parameters. Neither high- nor low-phosphate diet nor vitamin D affected endothelial function or arterial elasticity.Conclusions Increased phosphate intake (controlled for sodium) significantly increases SBP, DBP, and PR in humans with normal renal function, in part, by increasing sympathoadrenergic activity.

SERUM ELECTROLYTES AND OUTCOME IN PATIENTS UNDERGOING ENDOSCOPIC GASTROSTOMY.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) is a gold standard for long term enteral feeding. Neurologic dysphagia and head/neck cancer are the most common indications for PEG as they can lead to protein-energy malnutrition and serum electrolyte abnormalities, with potential negative impact on metabolic balance. Refeeding syndrome may also be related with severe electrolyte changes in PEG-fed patients and contribute to poor prognosis. OBJECTIVE: This study aims to evaluate the changes in serum concentrations of the main electrolytes and its possible association with the outcome. METHODS: Retrospective study of patients followed in our Artificial Nutrition Clinic, submitted to PEG from 2010 to 2016, having head/neck cancer or neurologic dysphagia, who died under PEG feeding. Serum electrolytes (sodium, potassium, chlorine, magnesium, calcium and phosphorus) were evaluated immediately before the gastrostomy procedure. Survival after PEG until death was recorded in months. RESULTS: We evaluated 101 patients, 59 with electrolyte alterations at the moment of the gastrostomy. Sodium was altered in 32 (31.7%), magnesium in 21 (20.8%), chlorine in 21 (20.8%), potassium in 14 (13.8%), calcium in 11 (10.9 %) and phosphorus in 11 (10.9%). The survival of patients with low sodium (<135 mmol/L) was significantly lower when compared to patients with normal/high values, 2.76 months vs 7.80 months, respectively (P=0.007). CONCLUSION: Changes in serum electrolytes of patients undergoing PEG were very common. More than half showed at least one abnormality, at the time of the procedure. The most frequent was hyponatremia, which was associated with significantly shorter survival, probably reflecting severe systemic metabolic distress.

Eletrólitos séricos e prognóstico em doentes submetidos a gastrostomia endoscópica / Serum electrolytes and outcome in patients undergoing endoscopic gastrostomy

ABSTRACT BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) is a gold standard for long term enteral feeding. Neurologic dysphagia and head/neck cancer are the most common indications for PEG as they can lead to protein-energy malnutrition and serum electrolyte abnormalities, with potential negative impact on metabolic balance. Refeeding syndrome may also be related with severe electrolyte changes in PEG-fed patients and contribute to poor prognosis. OBJECTIVE: This study aims to evaluate the changes in serum concentrations of the main electrolytes and its possible association with the outcome. METHODS: Retrospective study of patients followed in our Artificial Nutrition Clinic, submitted to PEG from 2010 to 2016, having head/neck cancer or neurologic dysphagia, who died under PEG feeding. Serum electrolytes (sodium, potassium, chlorine, magnesium, calcium and phosphorus) were evaluated immediately before the gastrostomy procedure. Survival after PEG until death was recorded in months. RESULTS: We evaluated 101 patients, 59 with electrolyte alterations at the moment of the gastrostomy. Sodium was altered in 32 (31.7%), magnesium in 21 (20.8%), chlorine in 21 (20.8%), potassium in 14 (13.8%), calcium in 11 (10.9 %) and phosphorus in 11 (10.9%). The survival of patients with low sodium (<135 mmol/L) was significantly lower when compared to patients with normal/high values, 2.76 months vs 7.80 months, respectively (P=0.007). CONCLUSION: Changes in serum electrolytes of patients undergoing PEG were very common. More than half showed at least one abnormality, at the time of the procedure. The most frequent was hyponatremia, which was associated with significantly shorter survival, probably reflecting severe systemic metabolic distress.

RESUMO CONTEXTO: A gastrostomia endoscópica percutânea (PEG) é a via de eleição preferencial para a nutrição entérica de longa duração. A disfagia neurológica e as neoplasias cervico-faciais constituem as principais indicações para PEG por poderem conduzir a desnutrição energético-proteica e alterações hidroeletrolíticas, com potencial impacto negativo no equilíbrio metabólico. A síndrome de realimentação pode também estar associada a alterações hidroeletrolíticas graves em doentes alimentados por PEG e contribuir para um mau prognóstico. OBJETIVO: Avaliar as alterações das concentrações séricas dos principais eletrólitos e a eventual associação entre os valores séricos alterados e o prognóstico dos doentes gastrostomizados. Métodos - Estudo retrospetivo realizado em doentes seguidos na Consulta de Nutrição Artificial do Hospital Garcia de Orta, propostos e submetidos a PEG, de 2010 a 2016 e que faleceram sob nutrição por PEG. Consideraram-se os valores séricos dos iões em estudo avaliados imediatamente antes do procedimento endoscópico de gastrostomia, obtidos por consulta do processo clínico. A sobrevida, após a realização da PEG até à morte foi registrada em meses. RESULTADOS: Avaliaram-se 101 doentes. A sobrevida média pós-gastrostomia foi 6,55 meses. Destes, 59 apresentaram alterações de alguns iões no momento da realização da PEG. O sódio estava alterado em 31 (30,6%), magnésio em 20 (19,8%), cloro em 19 (18,8%), potássio em 14 (13,8%), cálcio em 10 (9,9%) e o fósforo em 9 (8,9%). Quando comparada a sobrevida dos doentes com valores de sódio baixo (<135 mmol/L) com a dos doentes com valores normais/elevados, esta foi 2,76 meses vs 7,80 meses, respectivamente (P=0,007). CONCLUSÃO: As alterações dos eletrólitos séricos nos doentes submetidos a PEG foram muito frequentes, com mais de metade dos doentes a apresentarem pelo menos uma alteração aquando da realização do procedimento. A alteração mais frequente foi a hiponatrémia, associando-se a pior prognóstico com sobrevida significativamente mais curta, refletindo provavelmente um grave compromisso metabólico sistêmico.

Role of Vasopressin in Rat Models of Salt-Dependent Hypertension.

PURPOSE OF REVIEW: Dietary salt intake increases both plasma sodium and osmolality and therefore increases vasopressin (VP) release from the neurohypophysis. Although this effect could increase blood pressure by inducing fluid reabsorption and vasoconstriction, acute activation of arterial baroreceptors inhibits VP neurons via GABAA receptors to oppose high blood pressure. Here we review recent findings demonstrating that this protective mechanism fails during chronic high salt intake in rats. RECENT FINDINGS: Two recent studies showed that chronic high sodium intake causes an increase in intracellular chloride concentration in VP neurons. This effect causes GABAA receptors to become excitatory and leads to the emergence of VP-dependent hypertension. One study showed that the increase in intracellular chloride was provoked by a decrease in the expression of the chloride exporter KCC2 mediated by local secretion of brain-derived neurotrophic factor and activation of TrkB receptors. Prolonged high dietary salt intake can cause pathological plasticity in a central homeostatic circuit that controls VP secretion and thereby contribute to peripheral vasoconstriction and hypertension.

The effects of the chloride:sodium ratio on acid-base statusand mortality in septic patients.

BACKGROUND/AIM: Calculation of the chloride:sodium (Cl-:Na+) ratio is proposed to enable a quick evaluation of the effect of Cl- and Na+ on the acid-base balance in critically ill patients. In the present study, the relationship of the Cl-:Na+ ratio of septic patients with acid-base status and ICU mortality were investigated. MATERIALS AND METHODS: In our two-center study, 434 patients who were diagnosed with sepsis were included. The patients were divided into three groups: low (<0.75), normal (≥0.75, <0.80), and high (≥0.80) Cl-:Na+ ratio groups. Patients' demographic data, blood gas values, length of ICU stay, and ICU mortality were recorded. RESULTS: In the low and high groups, ICU mortality was significantly higher than in the normal group (29.3%, 37.1%) (P = 0.005). There was a negative correlation between the Cl:Na+ ratio and each of HCO3-, standard base excess, and PaCO2 (r2 = 0.21, r2 = 0.19, and r2 = 0.17) (P < 0.001 for each). In the multivariate analysis, the ICU mortality was increased 2.6-fold (1.2-5.8) by low Cl-:Na+ ratio (P = 0.019). CONCLUSION: The Cl-:Na+ ratio is a useful parameter for showing the relationship between Cl- and Na+ and their impact on acid-base status. Low Cl-:Na+ ratio at ICU admission can be used as a prognostic indicator for increased ICU mortality in septic patients.

Effect of Intravenous Infusion Solutions on Bioelectrical Impedance Spectroscopy.

BACKGROUND: Bioelectrical impedance (BIA) is often used to measure body fluid spaces and thereby body composition. However, in acute animal studies, we found that impedance was driven by the saline content of intravenous (IV) fluids and not by the volume. The aim of the study was to investigate the effect of 3 different fluids acutely administered on the change in impedance, specifically resistance (R). MATERIALS AND METHODS: Nine healthy adults participated in 3 treatment (0.9% saline, 5% dextrose, and a mixture of 0.3% saline + 3.3% dextrose) experiments on nonconsecutive days. They all received 1 L of one of the treatments intravenously over a 1-hour period. Repeated BIA measurements were performed prior to IV infusion and then every 5 minutes for the 1-hour infusion period, plus 3 more measurements up to 15 minutes after the completion of the infusion. RESULTS: The change in R in the 0.9% saline infusion experiment was significantly lower than that of the glucose and mixture treatment ( P < .001). CONCLUSION: Bioelectrical impedance spectroscopy and BIA measure salt rather than the volume changes over the infusion period. Hence, in patients receiving IV fluids, BIA of any kind (single frequency or multifrequency) cannot be used to measure body fluid spaces or body composition.

Hyperchloremia and moderate increase in serum chloride are associated with acute kidney injury in severe sepsis and septic shock patients.

BACKGROUND: Acute kidney injury and hyperchloremia are commonly present in critically ill septic patients. Our study goal was to evaluate the association of hyperchloremia and acute kidney injury in severe sepsis and septic shock patients. METHODS: In this retrospective cohort study in a provincial tertiary care hospital, adult patients with severe sepsis or septic shock and serum chloride measurements were included. Serum chloride was measured on a daily basis for 48 hours. Primary outcome was development of acute kidney injury (AKI) and association of AKI and serum chloride parameters was analyzed. RESULTS: A total of 240 patients were included in the study, 98 patients (40.8 %) had hyperchloremia. The incidence of acute kidney injury (AKI) was significantly higher in the hyperchloremia group (85.7 % vs 47.9 %; p < 0.001). Maximal chloride concentration in the first 48 hours ([Cl-]max) was significantly associated with AKI. In multivariate analysis, [Cl-]max was independently associated with AKI [adjusted odds ratio (OR) for AKI = 1.28 (1.02-1.62); p = 0.037]. The increase in serum chloride (Δ[Cl-] = [Cl-]max - initial chloride concentration) demonstrated a dose-dependent relationship with severity of AKI. The mean Δ[Cl-] in patients without AKI was 2.1 mmol/L while in the patients with AKI stage 1, 2 and 3 the mean Δ[Cl-] was 5.1, 5.9 and 6.7 mmol/L, respectively. A moderate increase in serum chloride (Δ[Cl-] ≥ 5 mmol/L) was associated with AKI [OR = 5.70 (3.00-10.82); p < 0.001], even in patients without hyperchloremia [OR = 8.25 (3.44-19.78); p < 0.001]. CONCLUSIONS: Hyperchloremia is common in severe sepsis and septic shock and independently associated with AKI. A moderate increase in serum chloride (Δ[Cl-] ≥5 mmol/L) is associated with AKI even in patients without hyperchloremia.