Hypervolemic hypernatremia in patients recovering from acute kidney injury in the intensive care unit

Plasma sodium during the recovery of renal function in critically ill adult patients: Multicenter prospective cohort study

BACKGROUND

Sodium increases during acute kidney injury (AKI) recovery. Both hypernatremia and positive fluid balances are associated with increased mortality. We aimed to evaluate the association between daily fluid balance and daily plasma sodium during the recovery from AKI among critical patients.

METHODS

Adult patients with AKI were enrolled in four ICUs and followed up for four days or until ICU discharge or hemodialysis initiation. Day zero was the peak day of creatinine. The primary outcome was daily plasma sodium; the main exposure was daily fluid balance.

RESULTS

93 patients were included. The median age was 66 years; 68% were male. Plasma sodium increased in 79 patients (85%), and 52% presented hypernatremia. We found no effect of daily fluid balance on plasma sodium (β -0.26, IC95%: -0.63-0.13; p = 0.19). A higher total sodium variation was observed in patients with lower initial plasma sodium (β -0.40, IC95%: -0.53 to -0.27; p < 0.01), higher initial urea (β 0.07, IC95%: 0.04-0.01; p < 0.01), and higher net sodium balance (β 0.002, IC95%: 0.0001-0.01; p = 0.05).

CONCLUSIONS

The increase in plasma sodium is common during AKI recovery and can only partially be attributed to the water and electrolyte balances. The incidence of hypernatremia in this population of patients is higher than in the general critically ill patient population.

Nomogram Prediction Model of Hypernatremia on Mortality in Critically Ill Patients

Objective

To investigate the value of hypernatremia in the intensive care unit (ICU) for the risk prediction of mortality in severe patients.

Methods

Clinical data of critically ill patients admitted to the ICU of Beijing Friendship Hospital, were collected for retrospective analysis. Univariate and multivariate logistic regression analyses were employed to analyze the influencing factors. Nomograms predicting the mortality were constructed with R software and validated with repeated sampling.

Results

A total of 442 cases were eligible for this study. Hypernatremia within 48 hours of ICU admission, change in sodium concentration (CNa+) within 48 hours, septic shock, APACHE II score, hyperlactatemia within 48 hours, use of continuous renal replacement therapy (CRRT) within 48 hours, and the use of mechanical ventilation (MV) within 48 hours of ICU admission were all identified as independent risk factors for death within 28 days of ICU admission. These predictors were included in a nomogram of 28-day mortality in severe patients, which was constructed using R software.

Conclusion

The nomogram could predict the individualized risk of 28-day mortality based on the above factors. The model has better discrimination and accuracy and has high clinical application value.

Nomogram Prediction Model of Serum Chloride and Sodium Ions on the Risk of Acute Kidney Injury in Critically Ill Patients

Purpose

This study aims to investigate the effect of serum chloride and sodium ions on AKI occurrence in ICU patients, and further constructs a prediction model containing these factors to explore the predictive value of these ions in AKI.

Methods

The clinical information of patients admitted to ICU of Beijing Friendship Hospital Affiliated to Capital Medical University was collected for retrospective analysis. Logistic regression analysis was used to analyzing the influencing factors. A nomogram for predicting AKI risk was constructed with R software and validated by repeated sampling. Afterwards, the effectiveness and accuracy of the model were tested and evaluated.

Results

A total of 446 cases met the requirements of this study, of which 178 developed AKI during their stay in ICU, with an incidence rate of 39.9%. Hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine value and BE value at ICU admission before the diagnosis of AKI were identified as independent risk factors for developing AKI during ICU stay. These predictors were incorporated into the nomogram of AKI risk in critically ill patients, which was constructed by using R software. Receiver operating characteristic curve analysis was further used and showed that the area under the curve of the model was 0.7934 (95% CI 0.742–0.8447), indicating that the model had an ideal value. Finally, further evaluated its clinical effectiveness. The clinical effect curve and decision curve showed that most areas of the decision curve of this model were greater than 0, indicating that this model owned a certain clinical effectiveness.

Conclusion

The nomogram based on hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine and BE value in ICU can predict the individualized risk of AKI with satisfactory distinguishability and accuracy.

Edelman Revisited: Concepts, Achievements, and Challenges

The key message from the 1958 Edelman study states that combinations of external gains or losses of sodium, potassium and water leading to an increase of the fraction (total body sodium plus total body potassium) over total body water will raise the serum sodium concentration ([Na]_S), while external gains or losses leading to a decrease in this fraction will lower [Na]_S. A variety of studies have supported this concept and current quantitative methods for correcting dysnatremias, including formulas calculating the volume of saline needed for a change in [Na]_S are based on it. Not accounting for external losses of sodium, potassium and water during treatment and faulty values for body water inserted in the formulas predicting the change in [Na]_S affect the accuracy of these formulas. Newly described factors potentially affecting the change in [Na]_S during treatment of dysnatremias include the following: (a) exchanges during development or correction of dysnatremias between osmotically inactive sodium stored in tissues and osmotically active sodium in solution in body fluids; (b) chemical binding of part of body water to macromolecules which would decrease the amount of body water available for osmotic exchanges; and (c) genetic influences on the determination of sodium concentration in body fluids. The effects of these newer developments on the methods of treatment of dysnatremias are not well-established and will need extensive studying. Currently, monitoring of serum sodium concentration remains a critical step during treatment of dysnatremias.

Early ICU-acquired hypernatraemia is associated with injury severity and preceded by reduced renal sodium and chloride excretion in polytrauma patients

PURPOSE

To further elucidate the origin of early ICU-acquired hypernatraemia.

MATERIAL AND METHODS

In this retrospective single-centre study, polytrauma patients requiring ICU treatment were analysed.

RESULTS

Forty-eight (47.5%) of 101 included polytrauma patients developed hypernatraemia within the first 7 days on ICU. They were more severely ill as described by higher SAPS III, ISS, daily SOFA scores and initial norepinephrine requirements as well as longer requirements of mechanical ventilation and ICU treatment in general. The development of hypernatraemia was neither attributable to fluid- or sodium-balances nor renal impairment. Although lower in the hypernatraemic group from day 4 onwards, median creatinine clearances were sufficiently high throughout the observation period. However, in the hypernatraemic group, urine sodium and chloride concentrations prior to the evolvement of hypernatraemia (56 (27-87) mmol/l and 39 (23-77) mmol/l) were significantly decreased when compared to i) the time after developing hypernatraemia (94 (58-134) mmol/l and 78 (36-115) mmol/l; p < 0.001) and ii) the non-hypernatraemic group in general (101 (66-143) mmol/l and 75 (47-109) mmol/l; p < 0.001).

CONCLUSIONS

Early ICU-acquired hypernatraemia is associated with injury severity and preceded by reduced renal sodium and chloride excretion in polytrauma patients.

Increased sodium intake and decreased sodium excretion in ICU-acquired hypernatremia: A prospective cohort study

PURPOSE

To provide more in-depth insight in the development of early ICU-acquired hypernatremia in critically ill patients based on detailed, longitudinal and quantitative data.

MATERIALS AND METHODS

A comparative analysis was performed using prospectively collected data of ICU patients. All patients requiring ICU admission for more than 48 h between April and December 2018 were included. For this study, urine samples were collected daily and analyzed for electrolytes and osmolality. Additionally, plasma osmolality analyses were performed. Further data collection consisted of routine laboratory results, detailed fluid balances and medication use.

RESULTS

A total of 183 patient were included for analysis, of whom 38% developed ICU-acquired hypernatremia. Whereas the hypernatremic group was similar to the non-hypernatremic group at baseline and during the first days, hypernatremic patients had a significantly higher sodium intake on day 2 to 5, a lower urine sodium concentration on day 3 and 4 and a worse kidney function (plasma creatinine 251 versus 71.9 μmol/L on day 5). Additionally, hypernatremic patients had higher APACHE IV scores (67 versus 49, p < 0.05) and higher ICU (23 versus 12%, p = 0.07) and 90-day mortality (33 versus 14%, p < 0.01).

CONCLUSIONS

Longitudinal analysis shows that the development of early ICU-acquired hypernatremia is preceded by increased sodium intake, decreased renal function and decreased sodium excretion.

Moringa oleifera ethanolic extract attenuates tilmicosin-induced renal damage in male rats via suppression of oxidative stress, inflammatory injury, and intermediate filament proteins mRNA expression

Tilmicosin (Til) is a popular macrolide antibiotic, widely used in veterinary practice. The present study was designed to address the efficacy of Moringa oleifera ethanolic extract (MOE) in protecting against Tilmicosin (Til) - induced nephrotoxicity in Sprague Dawley rats. Animals were treated once with Til (75 mg/kg bw, subcutaneously), and/or MOE for 7 days (400 or 800 mg/kg bw, by oral gavage). Til-treatment was associated with significantly increased serum levels of creatinine, urea, sodium, potassium and GGT activity, as well as decreased total protein and albumin concentrations. Renal tissue hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels were elevated, while the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes were diminished. The levels of renal tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) and the mRNA expression of intermediate filament protein encoding genes (desmin, nestin and vimentin) in the kidney were up- regulated with histopathological alterations in renal glomeruli, tubules and interstitial tissue. These toxic effects were markedly ameliorated by co-treatment of MOE with Til, in a dose dependent manner. Taken together, these results indicate that MO at 800 mg/kg protects against Til-induced renal injury, likely by its potent antioxidant and anti-inflammatory properties, which make it suitable to be used as a protective supplement with Til therapy.

Renal Function is a Major Determinant of ICU-acquired Hypernatremia: A Balance Study on Sodium Handling

Background and Objectives

The development of ICU-acquired hypernatremia (IAH) is almost exclusively attributed to ‘too much salt and too little water’. However, intrinsic mechanisms also have been suggested to play a role. To identify the determinants of IAH, we designed a prospective controlled study.

Methods

Patients with an anticipated length of stay ICU > 48 hours were included. Patients with hypernatremia on admission and/or on renal replacement therapy were excluded. Patients without IAH were compared with patients with borderline hypernatremia (≥ 143 mmol/L, IAH 143) and more severe hypernatremia (≥ 145 mmol/L, IAH 145).

Results

We included 89 patients, of which 51% developed IAH 143 and 29% IAH 145. Sodium intake was high in all patients. Fluid balances were slightly positive and comparable between the groups. Patients with IAH 145 were more severely ill on admission, and during admission, their sodium intake, cumulative sodium balances, serum creatinine and copeptin levels were higher. According to the free water clearance, all the patients conserved water. On multivariate analysis, the baseline serum creatinine was an independent risk factor for the development of IAH 143 and IAH 145. Also, the copeptin levels remained significant for IAH 143 and IAH 145. Sodium intake remained only significant for patients with IAH 145.

Conclusions

Our data support the hypothesis that IAH is due to the combination of higher sodium intake and a urinary concentration deficit, as a manifestation of the renal impairment elicited by severe illness.

High-sensitivity C-reactive protein as a predictive factor of acute kidney injury following aneurysmal subarachnoid hemorrhage: a prospective observational study

BACKGROUND

High-sensitivity C-reactive protein (hs-CRP) is a well-recognized biomarker of neurologic complications and clinical outcome of stroke patients. However, whether hs-CRP can predict the occurrence of acute kidney injury (AKI) in aneurysmal subarachnoid hemorrhage (aSAH) patients is still unclear. The objective of this study was to assess the feasibility of using serum hs-CRP level to predict the occurrence of AKI in aSAH patients.

METHODS

One hundred sixty-four aSAH patients were enrolled into a prospective observational study. AKI was diagnosed using the modified Kidney Disease Improving Global Outcomes (KDIGO) standard. The relationship between serum hs-CRP level at admission and occurrence of AKI was analyzed.

RESULTS

AKI occurred in 17 patients (10.4%) in this cohort. Patients with AKI had significantly higher hs-CRP levels than those without. The mortality of the AKI group tends to be higher than that of the non-AKI group, but the difference was not statistically significant (4/17 (23.5%) vs. 13/147 (8.8%), P = 0.081). After adjusting for possible confounding factors including World Federation of Neurosurgical Societies grade, diabetes, and serum creatinine, multivariate analysis revealed that serum hs-CRP level and antibiotic therapy were both significant factors independently associated with AKI following aSAH (serum hs-CRP: OR = 1.2, 95% confidence interval (CI) = 1.1-1.3, P = 0.003; antibiotic therapy: OR = 5.8, 95%CI = 1.6-20.7, P = 0.007). Receiver operating characteristic curve analysis showed that hs-CRP had a sensitivity of 76.5% and a specificity of 64.6% for predicting the development of AKI on the basis of the best thresholds. The post hoc log-rank test revealed that patients having serum hs-CRP level > 6.6 mg/L had a significantly higher AKI rate than patients having serum hs-CRP level ≤ 6.6 mg/L (P = 0.001).

CONCLUSIONS

Serum hs-CRP level might be helpful as a predictor for the development of AKI in aSAH patients. Delayed cerebral ischemia occurrence rate and mortality of patients with AKI tend to be higher than those of patients without in this cohort; however, they were not significantly different.

The role of urea-induced osmotic diuresis and hypernatremia in a critically ill patient: case report and literature review

Hypernatremia is a common electrolyte problem at the intensive care setting, with a prevalence that can reach up to 25%. It is associated with a longer hospital stay and is an independent risk factor for mortality. We report a case of hypernatremia of multifactorial origin in the intensive care setting, emphasizing the role of osmotic diuresis due to excessive urea generation, an underdiagnosed and a not well-known cause of hypernatremia. This scenario may occur in patients using high doses of corticosteroids, with gastrointestinal bleeding, under diets and hyperprotein supplements, and with hypercatabolism, especially during the recovery phase of renal injury. Through the present teaching case, we discuss a clinical approach to the diagnosis of urea-induced osmotic diuresis and hypernatremia, highlighting the utility of the electrolyte-free water clearance concept in understanding the development of hypernatremia.

PROTRACTED ACUTE HYPERVOLEMIC HYPERNATREMIA UNMASKED AFTER VASOPRESSIN THERAPY: CASE REPORT, LITERATURE REVIEW, AND PROPOSED ALGORITHMIC APPROACH

OBJECTIVE

Acute hypervolemic hypernatremia (HHN) is the most common form of hypernatremia in critical care settings. Previous reports implicated acute kidney injury and vasopressin withdrawal-induced central diabetes insipidus.

METHODS

We present the case of a 52-year-old woman who developed HHN after treatment of septic shock due to complicated bowel perforation.

RESULTS

After discontinuation of a 30-hour infusion of vasopressin analog, the patient manifested hypernatremia (150 to 156 mEq/L, equivalent to mmol/L) with hyponatriuria (49 mEq/L), hypoosmotic urine (163 mOsm/L), and polyuria (6.9 L/day) in a setting of cumulative positive fluid balance of 20.1 L. A trial of desmopressin yielded incomplete urinary concentration suggestive of renal resistance to desmopressin likely due to fluid overload. Despite positive water balance, her urine sodium was low at 36 to 49 mEq/L compared to serum sodium of 152 to 156 mEq/L. The hypernatremia with polyuria persisted for 16 days and resolved after treatment of the positive cumulative water balance (with controlled diuresis prioritizing natriuresis).

CONCLUSION

HHN may result in insufficient urine sodium clearance. We propose modifying the diagnostic/treatment algorithm by including HHN in a critical care setting, and recommending judicious administration of a loop diuretic to prioritize natriuria in hypernatremia with extreme cumulative fluid overload.

Predictors of Acute Kidney Injury in Neurocritical Care Patients Receiving Continuous Hypertonic Saline

BACKGROUND AND PURPOSE

Continuous intravenous 3% hypertonic saline (HTS) infusions are commonly used for the management of cerebral edema following severe neurologic injuries. Despite widespread use, data regarding the incidence and predictors of nephrotoxicity are lacking. The purpose of this study was to describe the incidence and identify predictors of acute kidney injury (AKI) in neurocritical care patients administered continuous infusion HTS.

METHODS

This was an institutional review board-approved, multicenter, retrospective cohort study of patients receiving HTS infusions at 2 academic medical centers. A univariate analysis and multivariable logistic regression were used to identify predictors of AKI. Data regarding AKI were evaluated during treatment with HTS and up to 24 hours after discontinuation.

RESULTS

A total of 329 patients were included in our analysis, with 54 (16%) developing AKI. Those who developed AKI experienced significantly longer stays in the intensive care unit (14.8 vs 11.5 days; P = .006) and higher mortality (48.1% vs 21.9%; P < .001). We identified past medical history of chronic kidney disease (odds ratio [OR]: 9.7, 95% confidence interval [CI]: 1.9-50.6; P = .007), serum sodium greater than 155 mmol/L (OR: 4.1, 95% CI: 2.1-8.0; P < .001), concomitant administration of piperacillin/tazobactam (OR: 3.9, 95% CI: 1.7-9.3; P = .002), male gender (OR: 3.2, 95% CI: 1.5-6.6; P = .002), and African American race (OR: 2.6, 95% CI: 1.3-5.2; P = .007) as independent predictors of AKI.

CONCLUSION

Acute kidney injury is relatively common in patients receiving continuous HTS and may significantly impact clinical outcomes.

Urine biochemistry assessment in critically ill patients: controversies and future perspectives

In the past, urine biochemistry was a major tool in acute kidney injury (AKI) management. Classic papers published some decades ago established the values of the urine indices which were thought to distinguish "pre-renal" (functional) AKI attributed to low renal perfusion and "renal" (structural) AKI attributed to acute tubular necrosis (ATN). However, there were a lot of drawbacks and limitations in these studies and some recent articles have questioned the utility of measuring urine electrolytes especially because they do not seem to adequately inform about renal perfusion nor AKI duration (transient vs. persistent). At the same time, the "pre-renal" paradigm has been consistently criticized because hypoperfusion followed by ischemia and ATN does not seem to explain most of the AKI developing in critically ill patients and distinct AKI durations do not seem to be clearly related to different pathophysiological mechanisms or histopathological findings. In this new context, other possible roles for urine biochemistry have emerged. Some studies have suggested standardized changes in the urine electrolyte composition preceding increases in serum creatinine independently of AKI subsequent duration, which might actually be due to intra-renal microcirculatory changes and activation of sodium-retaining mechanisms even in the absence of impaired global renal blood flow. In the present review, the points of controversy regarding urine biochemistry assessment were evaluated as well as future perspectives for its role in AKI monitoring. An alternative approach for the interpretation of measured urine electrolytes is proposed which needs further larger studies to be validated and incorporated in daily ICU practice.

Normal saline to dilute parenteral drugs and to keep catheters open is a major and preventable source of hypernatremia acquired in the intensive care unit

PURPOSE

We wanted to identify modifiable risk factors for intensive care unit (ICU)-acquired hypernatremia.

MATERIALS AND METHODS

We retrospectively studied sodium and fluid loads and balances up to 7 days prior to the development of hypernatremia (first serum sodium concentration, [Na+], >150 mmol/L; H) vs control (maximum [Na+] ≤150 mmol/L; N), in consecutive patients admitted into the ICU with a normal serum sodium (<145 mmol/L) and without cerebral disease, within a period of 8 months.

RESULTS

There were 57 H and 150 N patients. Severity of disease and organ failure was greater, and length of stay and mechanical ventilation in the ICU were longer in H (P<.001), with a mortality rate of 28% vs 16% in N (P=.002). Sodium input was higher in H than in N, particularly from 0.9% saline to dissolve drugs for infusion and to keep catheters open during the week prior to the first day of hypernatremia (P<.001). Fluid balances were positive and did not differ from N on most days in the presence of slightly higher plasma creatinine and more frequent administration of furosemide, at higher doses, in H than in N.

CONCLUSIONS

High sodium input by 0.9% saline used to dilute drugs and keep catheters open is a modifiable risk factor for ICU-acquired H. Dissolving drugs in dextrose 5% may partially prevent potentially harmful sodium overloading and H.

Understanding hypernatremia

Understanding hypernatremia is at times difficult for many clinicians. However, hypernatremia can often be deciphered easily with some basic understanding of water and sodium balance. Here, the basic pathophysiological abnormalities underlying the development of sodium disorders are reviewed, and case examples are given. Hypernatremia often arises in the hospital, especially in the intensive care units due to the combination of (1) not being able to drink water; (2) inability to concentrate the urine (most often from having kidney failure); (3) osmotic diuresis from having high serum urea concentrations, and (4) large urine or stool outputs.