Hypernatremia is a significant risk factor for acute kidney injury after subarachnoid hemorrhage: a retrospective analysis

Serum sodium concentration predicting mortality in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

To date, inconsistent evidence exists on the role of hypernatremia in patients with aneurysmal subarachnoid hemorrhage (aSAH) who underwent surgical clipping. We aimed to investigate the association between serum sodium and mortality in these patients.

METHODS

A cohort study was performed to include adult patients with aSAH who underwent surgical clipping in a university hospital. The primary outcome was follow-up mortality. Propensity score matching (PSM) was used for matching patients' baseline characteristics. Net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were calculated to assess and compare the reclassification and discrimination capacity of different models. Trends in serum sodium over time were detected by the ordinary least squares model.

RESULTS

Of 618 aSAH patients with surgical clipping during the study period, normal serum sodium was observed in 467 patients (75.6 %), and admission hypernatremia was noted in 151 patients (24.4 %). After adjustment with multivariate regression analysis, patients with hypernatremia had significantly higher odds for follow-up mortality (aOR: 2.86, 95 % CI: 1.54 to 5.30; P = 0.001). PSM analysis observed similar results (aOR: 2.38, 95 % CI: 1.29 to 4.55; P = 0.009). The incorporation of serum sodium during hospitalization markedly enhanced the IDI (P < 0.001) and NRI (P < 0.001) for the prediction of mortality.

CONCLUSIONS

In conclusion, the findings from this cohort study of aSAH patients with surgical clipping indicated that serum sodium can be an independent predictive factor of all-cause mortality, and inferior sequelae in aSAH patients. These findings endorsed the importance of managing hypernatremia and monitoring serum sodium in patients with aSAH.

Comparison of 4.54% hypertonic saline and 20% mannitol for brain relaxation during auditory brainstem implantation in pediatric patients: a single-center retrospective observational cohort study

BACKGROUND

Mannitol is frequently utilized to achieve intracranial brain relaxation during the retrosigmoid approach for auditory brainstem implantation (ABI). Hypertonic saline (HS) is an alternative for reducing intracranial pressure; however, its application during ABI surgery remains under-investigated. We aimed to compare the efficacy and safety between HS and mannitol for maintaining brain relaxation.

METHODS

This single-center retrospective cohort study included pediatric patients undergoing ABI surgery from September 2020 to January 2022 who received only 4.54% HS or 20% mannitol for brain relaxation. The analysis involved initial doses, subsequent doses, and dosing intervals of the two hyperosmolar solutions, as well as the time elapsed from meningeal opening to the first ABI electrode placement attempt. Additionally, the analysis encompassed electrolyte testing, hemodynamic variables, urine output, blood transfusion, second surgeries, adverse events, intensive care unit length of stay, and 30-day mortality.

RESULTS

We analyzed 68 consecutive pediatric patients; 26 and 42 in the HS and mannitol groups, respectively. The HS group exhibited a reduced rate of supplementary use (7.7% vs. 31%) and lower total urine volume. Perioperative outcomes, mortality, and length of intensive care unit stay did not exhibit significant between-group differences, despite transient increases in blood sodium and chloride observed within 2 h after HS infusion.

CONCLUSIONS

In pediatric ABI surgery, as an osmotherapy for cerebral relaxation, 4.54% HS demonstrated a lower likelihood of necessitating additional supplementation than 20% mannitol. Furthermore, the diuretic effect of HS was weak and the increase in electrolyte levels during surgery was temporary and slight.

Acute kidney injury in subarachnoid hemorrhage: Exploring its clinical significance and prognostic implications

OBJECTIVES

Subarachnoid hemorrhage (SAH) from spontaneous aneurysm rupture is a debilitating condition with high morbidity and mortality. Patients with SAH remain understudied, particularly concerning the evaluation of incidence and consequences of subsequent acute kidney injury (AKI). In this study, we aim to explore the risk factors and outcomes of AKI in SAH patients.

MATERIALS AND METHODS

International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes were used to query the National Inpatient Sample (NIS) for patients with a diagnosis of SAH between 2010-2019. Subgroup analysis was stratified by AKI diagnosis during the same hospitalization. AKI and non-AKI groups were assessed for baseline clinical characteristics, interventions, complications, and outcomes. Descriptive statistics, multivariate regressions, and propensity score-matching were performed using IBM SPSS 28.

RESULTS

Of 76,553 patients diagnosed with nontraumatic SAH between 2010-2019, 10,634 (13.89 %) had a comorbid diagnosis of AKI. SAH patients with AKI were older (p < 0.01) and more often obese (p < 0.01) compared to the non-AKI group. A multivariate regression found the diagnosis of AKI to be independently correlated with poor functional outcome (p < 0.001), above average length of stay (p < 0.001), and in-hospital mortality (p < 0.001) when controlling for age, SAH severity, and other comorbidities.

CONCLUSIONS

This study showed significant association between AKI and adverse outcomes in SAH patients, and a correlation between AKI and heightened complication rates, poor functional outcome, extended hospital stays, and elevated mortality rates. Early detection of AKI in SAH patients is vital to improve their chances of recovery.

Influence of Perioperative Three-Dimensional Computed Tomography (CT) Angiography and Surgical Clipping for Unruptured Cerebral Aneurysms on Renal Function in Patients with Chronic Kidney Disease

BACKROUND

Surgical clipping is a valuable treatment option for unruptured intracranial aneurysms in patients with chronic kidney disease (CKD). However, the comprehensive impact of clipping and perioperative three-dimensional computed tomography angiography (3D-CTA) on renal function remains unclear. This study aimed to evaluate the effects of perioperative 3D-CTA and surgical clipping on renal function in patients with CKD.

METHODS

We retrospectively analyzed 529 patients who underwent surgical clipping and perioperative 3D-CTA. An estimated glomerular filtration rate (eGFR) < 60 was defined as CKD. Patients were stratified according to their renal function (group 1: eGFR ≥60, group 2: 45 ≤ eGFR <60, group 3: 30 ≤ eGFR <45, group 4: eGFR <30 ml/min/1.73 m2), and eGFR was assessed preoperatively and 1 week and several months postoperatively.

RESULTS

Of the 529 patients, 442 did not have CKD and 87 had CKD. Hypertension, hyperlipidemia, and hyperuricemia were significantly more common in those with CKD. After the surgery and perioperative series of 3D-CTA, renal function deterioration was not observed in any group, whether in the acute or chronic postoperative period. Notably, eGFR significantly increased in groups 2 (66.7 ± 10.1, P < 0.01) and 3 (48.9 ± 9.2, P = 0.02) 1 week postoperatively, despite the CKD.

CONCLUSIONS

Surgical clipping of unruptured intracranial aneurysms and perioperative 3D-CTA with normal-dose contrast media did not impair renal function in patients with CKD. These results could be valuable in determining treatment strategies for those with CKD and intracranial aneurysms.

The Impact of Fluid Balance on Acute Kidney Injury in Nontraumatic Subarachnoid Hemorrhage

Background: Nontraumatic subarachnoid hemorrhage (SAH) can lead to poor neurologic outcomes, particularly when delayed cerebral ischemia (DCI) occurs. Maintenance of euvolemia following SAH is thought to reduce the risk of DCI. However, attempts at maintaining euvolemia often err on the side of hypervolemia. In this study, we assessed the relationship between fluid balance and acute kidney injury (AKI) in SAH patients, assessing hypervolemia versus euvolemia and their impact on AKI. Methods: In a quaternary care center, neuroscience intensive care unit we conducted a retrospective longitudinal analysis in adult patients who suffered a nontraumatic SAH. Results: Out of 139 patients, 15 (10.8%) patients developed an AKI while hospitalized, with 7 stage I, 3 stage II, and 5 stage III injuries. Acute kidney injury patients had higher peak sodium (150.1 mEq/L vs 142.7 mEq/L, 95% confidence interval [CI]: [2.7-12.1 mEq/L]), higher discharge chloride (109.1 mEq/L vs 104.9 mEq/L, 95% CI: [0.7-7.6 mEq/L]), and lower hemoglobin at discharge (9.3 g/dL vs 11.3 g/dL, 95% CI: [1.0-2.9 g/dL]). At 7 days, AKI patients had a fluid balance that was 1.82 L higher (P = .04), and 3.38 L higher at 14 days (P = .02), in comparison to day 3. Acute kidney injury was associated with significant mortality increases. This increase in mortality was found at 30 days from admission with a 9.52-fold increase, and at 60 days with a 6.25-fold increase. As a secondary outcome, vasospasm (19 patients, 13.7%) showed no association with AKI. Conclusions: Acute kidney injury following SAH is correlated with clinically significant hypervolemia, elevated sodium, elevated chloride, decreased urine output, and decreased hemoglobin at discharge-risk factors for all SAH patients. This study further elucidates the harm of hypervolemia and gives greater practical evidence to physicians attempting to balance the dangers of vasospasm and AKI.

A prognostic model incorporating the albumin-corrected anion gap in patients with aneurysmal subarachnoid hemorrhage

Background

Aneurysmal subarachnoid hemorrhage (aSAH) patients typically have poor prognoses. The anion gap (AG) has been proven to correlate with mortality in various critically ill patients. However, hypoalbuminemia can lead to underestimations of the true anion gap levels. This study was conducted to verify the prognostic value of single AG and albumin-corrected anion gap (ACAG) among aSAH patients.

Methods

Significant factors in the univariate logistic regression analysis were included in the multivariate logistic regression analysis to explore the risk factors for mortality in aSAH patients and to confirm the independent relationship between ACAG and mortality. The restricted cubic spline (RCS) was used to visually show the relationship between ACAG level and mortality risk of aSAH patients. The predictive model for mortality was developed by incorporating significant factors into the multivariate logistic regression analysis. The prognostic value of ACAG and the developed model was evaluated by calculating the area under the receiver operating characteristics curve (AUC).

Results

Among 710 aSAH patients, a 30-day mortality was observed in 20.3% of the cases. A positive relationship was demonstrated between the ACAG level and mortality in aSAH patients using the RCS curve. The multivariate logistic regression analysis helped discover that only six factors were finally and independently related to mortality of aSAH patients after adjusting for confounding effects, including the Hunt-Hess scale score (p = 0.006), surgical options (p < 0.001), white blood cell count (p < 0.001), serum chloride levels (p = 0.023), ACAG (p = 0.039), and delayed cerebral ischemia (p < 0.001). The AUC values for the AG, albumin, and ACAG in predicting mortality among aSAH patients were 0.606, 0.536, and 0.617, respectively. A logistic regression model, which includes the Hunt-Hess scale score, surgical options, white blood cell count, serum chloride levels, ACAG, and delayed cerebral ischemia, achieved an AUC of 0.911 for predicting mortality.

Conclusion

The ACAG is an effective prognostic marker for aSAH patients. A prognostic model incorporating ACAG could help clinicians evaluate the risk of poor outcomes among aSAH patients, thereby facilitating the development of personalized therapeutic strategies.

Acute kidney injury in neurocritical care

Approximately 20% of patients with acute brain injury (ABI) also experience acute kidney injury (AKI), which worsens their outcomes. The metabolic and inflammatory changes associated with AKI likely contribute to prolonged brain injury and edema. As a result, recognizing its presence is important for effectively managing ABI and its sequelae. This review discusses the occurrence and effects of AKI in critically ill adults with neurological conditions, outlines potential mechanisms connecting AKI and ABI progression, and highlights AKI management principles. Tailored approaches include optimizing blood pressure, managing intracranial pressure, adjusting medication dosages, and assessing the type of administered fluids. Preventive measures include avoiding nephrotoxic drugs, improving hemodynamic and fluid balance, and addressing coexisting AKI syndromes. ABI patients undergoing renal replacement therapy (RRT) are more susceptible to neurological complications. RRT can negatively impact cerebral blood flow, intracranial pressure, and brain tissue oxygenation, with effects tied to specific RRT methods. Continuous RRT is favored for better hemodynamic stability and lower risk of dialysis disequilibrium syndrome. Potential RRT modifications for ABI patients include adjusted dialysate and blood flow rates, osmotherapy, and alternate anticoagulation methods. Future research should explore whether these strategies enhance outcomes and if using novel AKI biomarkers can mitigate AKI-related complications in ABI patients.

Hypernatremia: Epidemiology and Predictive Role in Emerging and Established Acute Kidney Injury

Hypernatremia (plasma sodium > 145 mmol/L) reflects impaired water balance, and affected patients can suffer from severe neurologic symptoms. Hyponatremia, on the other hand, is the most frequent electrolyte disorder in hospitals. It may be diagnosed in acute kidney injury (AKI), but hyponatremia prior to the diagnosis of AKI has also predictive or prognostic value in the short term. Aim of the article was to summarize data on both, epidemiology and outcomes of in-hospital acquired hypernatremia ("In-hospital acquired" refers to the diagnosis of either hypo- or hypernatremia in patients, who did not exhibit any of these electrolyte imbalances upon admission to the hospital). It also aimed to discuss its predictive role in patients with emerging or established AKI. Five databases were searched for references: PubMed, Medline, Google Scholar, Scopus, and Cochrane Library. Studies published between 2000 and 2023 were screened. The following keywords were used: "hypernatremia", "mortality", "pathophysiology", "acute kidney injury", "AKI", "risk prediction", "kidney replacement therapy", "KRT", "renal replacement therapy", "RRT", "hyponatremia", and "heart failure". A total of 16 studies were deemed eligible for inclusion. Among these, 13 studies had a retrospective design, two investigations were published as secondary analyses from prospective trial cohorts, and one study was prospective in nature. Out of the 16 studies, 11 focused on the epidemiology and outcomes of hypernatremia, while five investigations were related to AKI and/or AKI-associated endpoints. The prevalence of hypernatremia diagnosed during hospitalization varied from 1.9% to 6.8%, with one exception where it was 30.8%. All studies demonstrated associations between hypernatremia and mortality, even over extended periods after discharge. In AKI patients, hypernatremia shows potential for predicting in-hospital death. In conclusion, hypernatremic individuals are at higher risk of death during in-hospital therapy. Also, the electrolyte disorder potentially qualifies as a future biomarker for AKI onset and AKI-associated mortality.

Prevention and Correction of Dysnatremia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Dysnatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). The mechanisms for development of sodium dyshomeostasis are complex, including the cerebral salt-wasting syndrome, the syndrome of inappropriate secretion of antidiuretic hormone, diabetes insipidus. Iatrogenic occurrence of altered sodium levels plays a role, as sodium homeostasis is tightly linked to fluid and volume management.

METHODS

Narrative review of the literature.

RESULTS

Many studies have aimed to identify factors predictive of the development of dysnatremia, but data on associations between dysnatremia and demographic and clinical variables are variable. Furthermore, although a clear relationship between serum sodium serum concentrations and outcomes has not been established-poor outcomes have been associated with both hyponatremia and hypernatremia in the immediate period following aSAH and set the basis for seeking interventions to correct dysnatremia. While sodium supplementation and mineralocorticoids are frequently administered to prevent or counter natriuresis and hyponatremia, evidence to date is insufficient to gauge the effect of such treatment on outcomes.

CONCLUSIONS

In this article, we reviewed available data and provide a practical interpretation of these data as a complement to the newly issued guidelines for management of aSAH. Gaps in knowledge and future directions are discussed.

Plasma anion gap and risk of in-hospital mortality in patients with spontaneous subarachnoid hemorrhage

Background

The association between the serum anion gap (AG) and prognosis of patients with spontaneous subarachnoid hemorrhage (SAH) remains unknown. Thus, this study aimed to explore the association between AG levels and mortality in patients with SAH in the intensive care unit (ICU).

Methods

This was a retrospective analysis of data stored in the Medical Information Mart for Intensive Care–IV and eICU Collaborative Research databases. Critically ill patients diagnosed with spontaneous SAH were included. The primary outcome measure was in-hospital all-cause mortality. A multivariate Cox proportional hazards regression model and a restricted cubic spline were used to evaluate the relationship between AG concentration and outcomes. Kaplan–Meier curves were used to compare cumulative survival among patients with AG levels.

Results

A total of 1,114 patients were enrolled. AG concentration was significantly associated with in-hospital all-cause mortality [hazard ratio ([HR], 1.076 (95% confidence interval (CI), 1.021–1.292; p = 0.006)]. The risk of mortality was higher in the Category 2 group (AG ≥10 mmol/L and <13 mmol/L; HR, 1.961; 95% CI, 1.157–3.324; p = 0.0) and the Category 3 group (AG ≥13 mmol/L; HR, 2.151; 95% CI, 1.198–3.864; p = 0.010) than in the Category 1 group (AG < 10 mmol/L). Cumulative survival rates were significantly lower in patients with higher AG levels (log-rank p < 0.001).

Conclusions

In-hospital and ICU mortalities increase with increasing AG concentration in patients with SAH. An increased serum AG level is an independent, significant, and robust predictor of all-cause mortality. Thus, serum AG levels may be used in the risk stratification of SAH.

Association of early dysnatremia with mortality in the neonatal intensive care unit: results from the AWAKEN study

OBJECTIVE

To determine the association of dysnatremia in the first postnatal week and risk of acute kidney injury (AKI) and mortality.

STUDY DESIGN

A secondary analysis of 1979 neonates in the AWAKEN cohort evaluated the association of dysnatremia with (1) AKI in the first postnatal week and (2) mortality, utilizing time-varying Cox proportional hazard models.

RESULT

Dysnatremia developed in 50.2% of the cohort and was not associated with AKI. Mortality was associated with hyponatremia (HR 2.15, 95% CI 1.07-4.31), hypernatremia (HR 4.23, 95% CI 2.07-8.65), and combined hypo/hypernatremia (HR 6.39, 95% CI 2.01-14.01). In stratified models by AKI-status, hypernatremia and hypo/hypernatremia increased risk of mortality in neonates without AKI.

CONCLUSION

Dysnatremia within the first postnatal week was associated with increased risk of mortality. Hypernatremia and combined hypo/hypernatremia remained significantly associated with mortality in neonates without AKI. This may reflect fluid strategies kidney injury independent of creatinine and urine-output defined AKI, and/or systemic inflammation.

Associations of Dysnatremia with COVID-19 Status and Mortality

Background

In patients without COVID-19, dysnatremia is associated with mortality. These relationships are not well established in patients with COVID-19. We tested the hypotheses that patients with COVID-19 were more likely to have dysnatremia than those without COVID-19 and that, among those with COVID-19, dysnatremia is associated with mortality.

Methods

We conducted a retrospective observational study of patients admitted to a tertiary care center in the Bronx, New York, during the COVID-19 surge from March 11 to April 26, 2020. Using multinomial logistic regression models, we compared the prevalence of hypernatremia (serum sodium ≥150 mEq/L) and hyponatremia (serum sodium <130 mEq/L) on admission between patients with and without COVID-19. Among patients with COVID-19, we used Cox proportional hazards models to examine the association of dysnatremia with mortality.

Results

Compared with those without COVID-19 (n=1265), patients with COVID-19 (n=3345) had a higher prevalence of hypernatremia (7% versus 4%, P<0.001) and hyponatremia (7% versus 6%, P=0.04). In adjusted models, COVID-19-positive patients had a higher likelihood of having hypernatremia (adjusted odds ratio=1.87, 95% CI, 1.3 to 2.57, P=0.001) compared with COVID-19-negative patients, whereas the association between hyponatremia and COVID-19 status was no longer significant (P=0.06). Among patients with COVID-19, 775 (23%) died after a median follow-up of 17 days (IQR 7-27 days). Among nonsurvivors, 15% had hypernatremia and 8% had hyponatremia on admission. Hypernatremia was associated with a higher risk of mortality (adjusted hazard ratio=1.28, 95% CI, 1.01 to 1.63, P=0.04) compared with patients with eunatremia.

Conclusions

In patients hospitalized during the spring 2020 COVID-19 surge, COVID-19 status was associated with hypernatremia on admission. Among patients with COVID-19, hypernatremia was associated with higher mortality. Hypernatremia may be a potential prognostic marker for mortality in COVID-19 patients.

Early Acute Kidney Injury in Patients with Non-Traumatic Subarachnoid Hemorrhage who Undergo Catheter Angiography: Incidence, Associated Risk Factors and Impact on Outcome

OBJECTIVES

After subarachnoid hemorrhage (SAH), potential renal insults are numerous but the burden of early acute kidney injury (AKI) is unclear. We determined its incidence, rate of persistence, risk factors, and impact on patients' outcomes.

MATERIALS AND METHODS

Patients with non-traumatic SAH were retrospectively included if they underwent catheter angiography within the 48 h after their admission to the intensive care unit. Early AKI was defined according to Kidney Disease Improving Global Outcome (KDIGO) criteria, analyzed from the time of catheter angiography. Early AKI was considered as persistent if the KDIGO stage did not decrease between the 48th and the 60th hour.

RESULTS

Among 499 consecutive patients, early AKI (mostly oliguria) occurred in 132 (26%): stage 1, 2 and 3 in 72 (14%), 44 (9%), and 16 (3%) patients, respectively. It persisted in 36% of cases. Early AKI occurred more likely when SAH was severe or renal function was impaired at hospital admission: adjusted odds ratio of 2.76 [95% 1.77-4.30] and 3.32 [1.17-9.46], respectively. ICU and hospital lengths of stay were longer in patients who developed early AKI than in patients who did not: 16 [9-29] versus 12 [4-24] days (p = 0.0003) and 21 [14-43] versus 16 [11-32] days (p = 0.007), respectively. There was an independent link between early AKI and renal outcome (n = 274 in the model) but not with hospital mortality (n = 453).

CONCLUSIONS

One quarter of our population developed early AKI, mostly oliguria. It persisted beyond the 48th hour in one third of cases. The associated risk factors we identified were non-modifiable.

A nomogram based on serum cystatin C for predicting acute kidney injury in patients with traumatic brain injury

BACKGROUND

Acute kidney injury (AKI) is a common complication in traumatic brain injury (TBI) patients and is associated with unfavorable outcome of these patients. We designed this study to explore the value of serum cystatin C, an indicator of renal function, on predicting AKI after suffering TBI.

METHODS

Patients confirmed with TBI and hospitalized in the West China Hospital of Sichuan University between January 2015 and December 2019 were included. Patients were divided into two groups according to occurrence of AKI. Univariate and multivariate logistic regression analyses were sequentially utilized to find risk factors of AKI in included TBI patients. Nomogram composed of discovered risk factors for predicting AKI was constructed. Receiver operating characteristics (ROC) curves were drawn and area under the ROC curve (AUC) were calculated to evaluate the predictive value of cystatin C alone and the constructed nomogram.

RESULTS

Among 234 included TBI patients, 55 were divided into AKI group. AKI group had shorter length of stay (p < 0.001) and higher in-hospital mortality (p < 0.001). Multivariate logistic regression analysis showed absolute lymphocyte count (p = 0.034), serum creatinine (p < 0.001), serum cystatin C (p = 0.017) and transfusion of red blood cell (p = 0.005) were independently associated with development of AKI after TBI. While hypertonic saline use was not associated with the development of AKI (p = 0.067). The AUC of single cystatin C and predictive nomogram were 0.804 and 0.925, respectively.

CONCLUSION

Higher serum cystatin C is associated with development of AKI in TBI patients. Predictive nomogram incorporating cystatin C is beneficial for physicians to evaluate possibilities of AKI and consequently adjust treatment strategies to avoid occurrence of AKI.

Incidence and Burden of Acute Kidney Injury among Traumatic Brain-Injury Patients

Background

Acute kidney injury (AKI) has been occurs commonly in the clinical management of traumatic brain injury (TBI) patients and is correlated with outcomes in these patients. We designed this study to investigate the incidence, duration, stage, and burden of AKI among these patients.

Methods

A total of 419 TBI inpatients at our hospital were included in the study. We calculated the AKI burden, reflecting both stage and duration, and then analyzed associations among AKI occurrence, highest AKI stage, AKI duration, AKI burden, and outcomes with logistic regression analysis.

Results

Incidence of AKI among TBI patients was 19.8%. These patients’ AKIs occurred mainly on the first day from admission (10.74%), and mostly developed stage 1 AKI (9.79%). Modes of AKI duration and burden in those with AKI were both 1. Multivariate logistic regression showed AKI occurrence (OR 3.792, p=0.004) and the highest AKI stage (OR 3.122, p<0.001) was significantly associated with mortality. Neither AKI duration (OR 1.083, p=0.206) nor AKI burden (OR 1.062, p=0.171) were associated with mortality. Incorporating AKI occurrence or highest AKI stage did not improve the predictive value of the constructed prognostic model.

Conclusion

The high-incidence period of AKI in TBI patients was the first 3 days after admission. AKI occurrence and highest AKI stage were associated with mortality, while AKI duration and AKI burden were not associated with mortality.

Association Between Serum Osmolality and Acute Kidney Injury in Critically Ill Patients: A Retrospective Cohort Study

Purposes: Acute kidney injury (AKI) is a common complication in critically ill patients and is usually associated with poor outcomes. Serum osmolality has been validated in predicting critically ill patient mortality. However, data about the association between serum osmolality and AKI is still lacking in ICU. Therefore, the purpose of the present study was to investigate the association between early serum osmolality and the development of AKI in critically ill patients.

Methods: The present study was a retrospective cohort analysis based on the medical information mart for intensive care III (MIMIC-III) database. 20,160 patients were involved in this study and divided into six subgroups according to causes for ICU admission. The primary outcome was the incidence of AKI after ICU admission. The association between early serum osmolality and AKI was explored using univariate and multivariate logistic regression analyses.

Results: The normal range of serum osmolality was 285–300 mmol/L. High serum osmolality was defined as serum osmolality >300 mmol/L and low serum osmolality was defined as serum osmolality <285 mmol/L. Multivariate logistic regression indicated that high serum osmolality was independently associated with increased development of AKI with OR = 1.198 (95% CL = 1.199–1.479, P < 0.001) and low serum osmolality was also independently associated with increased development of AKI with OR = 1.332 (95% CL = 1.199–1.479, P < 0.001), compared with normal serum osmolality, respectively.

Conclusions: In critically ill patients, early high serum osmolality and low serum osmolality were both independently associated with an increased risk of development of AKI.

Acute Kidney Injury at the Neurocritical Care Unit

Neurocritical care has advanced substantially in recent decades, allowing doctors to treat patients with more complicated conditions who require a multidisciplinary approach to achieve better clinical outcomes. In neurocritical patients, nonneurological complications such as acute kidney injury (AKI) are independent predictors of worse clinical outcomes. Different research groups have reported an AKI incidence of 11.6% and an incidence of stage 3 AKI, according to the Kidney Disease: Improving Global Outcomes, that requires dialysis of 3% to 12% in neurocritical patients. These patients tend to be younger, have less comorbidity, and have a different risk profile, given the diagnostic and therapeutic procedures they undergo. Trauma-induced AKI, sepsis, sympathetic overstimulation, tubular epitheliopathy, hyperchloremia, use of nephrotoxic drugs, and renal hypoperfusion are some of the causes of AKI in neurocritical patients. AKI is the result of a sum of events, although the mechanisms underlying many of them remain uncertain; however, two important causes that merit mention are direct alteration of the physiological brain-kidney connection and exposure to injury as a result of the specific medical management and well-established therapies that neurocritical patients are subjected to. This review will focus on AKI in neurocritical care patients. Specifically, it will discuss its epidemiology, causes, associated mechanisms, and relationship to the brain-kidney axis. Additionally, the use and risks of extracorporeal therapies in this group of patients will be reviewed.

Acute Kidney Injury in Traumatic Brain Injury Patients: Results From the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury Study

OBJECTIVES

Acute kidney injury is frequent in polytrauma patients, and it is associated with increased mortality and extended hospital length of stay. However, the specific prevalence of acute kidney injury after traumatic brain injury is less recognized. The present study aims to describe the occurrence rate, risk factors, timing, and association with outcome of acute kidney injury in a large cohort of traumatic brain injury patients.

DESIGN

The Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury is a multicenter, prospective observational, longitudinal, cohort study.

SETTING

Sixty-five ICUs across Europe.

PATIENTS

For the present study, we selected 4,509 traumatic brain injury patients with an ICU length of stay greater than 72 hours and with at least two serum creatinine values during the first 7 days of ICU stay.

MEASUREMENTS AND MAIN RESULTS

We classified acute kidney injury in three stages according to the Kidney Disease Improving Global Outcome criteria: acute kidney injury stage 1 equals to serum creatinine × 1.5-1.9 times from baseline or an increase greater than or equal to 0.3 mg/dL in 48 hours; acute kidney injury stage 2 equals to serum creatinine × 2-2.9 times baseline; acute kidney injury stage 3 equals to serum creatinine × three times baseline or greater than or equal to 4 mg/dL or need for renal replacement therapy. Standard reporting techniques were used to report incidences. A multivariable Cox regression analysis was performed to model the cause-specific hazard of acute kidney injury and its association with the long-term outcome. We included a total of 1,262 patients. The occurrence rate of acute kidney injury during the first week was as follows: acute kidney injury stage 1 equals to 8% (n = 100), acute kidney injury stage 2 equals to 1% (n = 14), and acute kidney injury stage 3 equals to 3% (n = 36). Acute kidney injury occurred early after ICU admission, with a median of 2 days (interquartile range 1-4 d). Renal history (hazard ratio = 2.48; 95% CI, 1.39-4.43; p = 0.002), insulin-dependent diabetes (hazard ratio = 2.52; 95% CI, 1.22-5.197; p = 0.012), hypernatremia (hazard ratio = 1.88; 95% CI, 1.31-2.71; p = 0.001), and osmotic therapy administration (hazard ratio = 2.08; 95% CI, 1.45-2.99; p < 0.001) were significantly associated with the risk of developing acute kidney injury. Acute kidney injury was also associated with an increased ICU length of stay and with a higher probability of 6 months unfavorable Extended Glasgow Outcome Scale and mortality.

CONCLUSIONS

Acute kidney injury after traumatic brain injury is an early phenomenon, affecting about one in 10 patients. Its occurrence negatively impacts mortality and neurologic outcome at 6 months. Osmotic therapy use during ICU stay could be a modifiable risk factor.

Risk Scoring Systems Including Electrolyte Disorders for Predicting the Incidence of Acute Kidney Injury in Hospitalized Patients

Introduction

Electrolyte disorders are common among hospitalized patients with acute kidney injury (AKI) and adversely affect the outcome. This study aimed to explore the potential role of abnormal electrolyte levels on predicting AKI and severe AKI.

Methods

In this retrospective, observational study, we included all hospitalized patients in our hospital in China from October 01, 2014, to September 30, 2015. Since only a few patients had arterial blood gas analysis (ABG), all subjects involved were divided into two groups: patients with ABG and patients without ABG. Severe AKI was defined as AKI stage 2 or 3 according to KDIGO guideline.

Results

A total of 80,091 patients were enrolled retrospectively and distributed randomly into the test cohort and the validation cohort (2:1). Logistic regression was performed in the test cohort to analyze risk factors including electrolyte disorders and elucidate the association. The test data (derivation cohort) led to AUC values of 0.758 (95% CI: 0.743–0.773; AKI with ABG), 0.751 (95% CI: 0.740–0.763; AKI without ABG), 0.733 (95% CI: 0.700–0.767; severe AKI with ABG), 0.853 (95% CI: 0.824–0.882; severe AKI without ABG). Application of the scoring system in the validation cohort led to AUC values of 0.724 (95% CI: 0.703–0.744; AKI with ABG), 0.738 (95% CI: 0.721–0.755; AKI without ABG), 0.774 (95% CI: 0.732–0.815; severe AKI with ABG), 0.794 (95% CI: 0.760–0.827; severe AKI without ABG). Hosmer–Lemeshow tests revealed a good calibration.

Conclusion

The risk scoring systems involving electrolyte disorders were established and validated adequately efficient to predict AKI and severe AKI in hospitalized patients. Electrolyte imbalance needs to be carefully monitored and corrections should be made on time to avoid further adverse outcome.

Risk factors for renal failure and short-term prognosis in patients with spontaneous intracerebral haemorrhage complicated by acute kidney injury

Background

Although acute kidney injury (AKI) is a known risk factor for adverse clinical outcomes in patients with spontaneous intracerebral haemorrhage (SICH), little is known about the predisposing factors that contribute to renal failure and short-term prognosis in the setting of SICH already complicated by AKI. In this study, we aimed to identify the renal failure factors in SICH patents with AKI.

Methods

Five hundred forty-three patients with SICH complicated by differential severities of AKI who were admitted to the First Affiliated Hospital of Fujian Medical University from January 2016 to December 2018 were retrospectively studied. Logistic regression and receiver operator characteristic (ROC) curve analysis were performed to determine the best predictive and discriminative variables. Multivariate Cox regression analysis was performed to identify prognostic factors for renal recovery.

Results

In the multivariable adjusted model, we found that hypernatremia, metabolic acidosis, elevated serum creatine kinase, hyperuricaemia, proteinuria, and the use of colloids and diuretics were all independent risk factors for the occurrence of stage 3 AKI in SICH patients. The area under the curve analysis indicated that hypernatremia and hyperuricaemia were predictive factors for stage 3 AKI, and the combination of these two parameters increased their predictability for stage 3 AKI. Kaplan-Meier survival curves revealed that the renal recovery rate in SICH patients with stages 1 and 2 AKI was significantly higher than that in SICH patients with stage 3 AKI. Multivariate Cox regression analysis suggested that hypernatremia and the occurrence of stage 3 AKI are predictors for poor short-term renal recovery.

Conclusions

These findings illustrate that hypernatremia and hyperuricaemia represent potential risk factors for the occurrence of stage 3 AKI in SICH patients. Those patients with hypernatremia and stage 3 AKI were associated with a poor short-term prognosis in renal recovery.

Effect of mannitol plus hypertonic saline combination versus hypertonic saline monotherapy on acute kidney injury after traumatic brain injury

PURPOSE

To compare the effect of mannitol plus hypertonic saline combination (MHS) versus hypertonic saline monotherapy (HS) on renal function in patients with traumatic brain injury (TBI).

MATERIALS AND METHODS

This was a secondary analysis of data from the Resuscitation Outcomes Consortium Hypertonic Saline Trial Shock Study and Traumatic Brain Injury Study. The study cohort included a propensity matched subset of patients with TBI who received MHS or HS. The primary outcome measure was the maximum serum creatinine value during critical illness.

RESULTS

The cohort consisted of 163 patients in the MHS group and 163 patients in the HS group (n = 326). The maximum serum creatinine value during hospitalization was 82 ± 47 μmol/L (0.86 ± 0.26 mg/dL) in the MHS group and 76 ± 23 μmol/L (0.92 ± 0.53 mg/dL) in the HS group (difference -6 μmol/L, 95% CI -14 to 2 μmol/L, p = .151). The lowest eGFR during hospitalization was 108 ± 25 mL/min in the MHS group and 112 ± 24 mL/min in the HS group (difference -4 mL/min, 95% CI -1 to 9 mLmin, p = .150).

CONCLUSIONS

The addition of mannitol to HS did not increase the risk of renal dysfunction compared to HS alone in patients with TBI.

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.

New determinants for casual peripheral mechanism of neurogenic lung edema in subarachnoid hemorrhage due to ischemic degeneration of vagal nerve, kidney and lung circuitry. Experimental study1

Purpose

To evaluate whether there is a relationship between renal artery vasospasm related low glomerular density or degeneration and neurogenic lung edema (NLE) following subarachnoid hemorrhage.

Methods

This study was conducted on 26 rabbits. A control group was formed of five animals, a SHAM group of 5 to which saline and a study group (n=16) injected with homologous blood into the sylvian cisterna. Numbers of degenerated axons of renal branches of vagal nerves, atrophic glomerulus numbers and NLE scores were recorded.

Results

Important vagal degeneration, severe renal artery vasospasm, intrarenal hemorrhage and glomerular atrophy observed in high score NLE detected animals. The mean degenerated axon density of vagal nerves (n/mm²), atrophic glomerulus density (n/mm³) and NLE scores of control, SHAM and study groups were estimated as 2.40±1.82, 2.20±1.30, 1.80±1.10, 8.00±2.24, 8.80±2.39, 4.40±1.14 and 154.38±13.61, 34.69±2.68 and 12.19±1.97 consecutively. Degenerated vagal axon, atrophic glomerulus and NLE scores are higher in study group than other groups and the differences are statistically meaningful (p<0.001).

Conclusion

Vagal complex degeneration based glomerular atrophy have important roles on NLE following SAH which has not been extensively mentioned in the literature.

Therapeutic hypernatremia management during continuous renal replacement therapy with elevated intracranial pressures and respiratory failure

Cerebral edema and elevated intracranial pressure (ICP) are common complications of acute brain injury. Hypertonic solutions are routinely used in acute brain injury as effective osmotic agents to lower ICP by increasing the extracellular fluid tonicity. Acute kidney injury in a patient with traumatic brain injury and elevated ICP requiring renal replacement therapy represents a significant therapeutic challenge due to an increased risk of cerebral edema associated with intermittent conventional hemodialysis. Therefore, continuous renal replacement therapy (CRRT) has emerged as the preferred modality of therapy in this patient population. We present our current treatment approach, with demonstrative case vignette illustrations, utilizing hypertonic saline protocols (3% sodium-chloride or, with coexisting severe combined metabolic and respiratory acidosis, with 4.2% sodium-bicarbonate) in conjunction with the CRRT platform, to induce controlled hypernatremia of approximately 155 mEq/L in hemodynamically unstable patients with acute kidney injury and elevated ICP due to acute brain injury. Rationale, mechanism of activation, benefits and potential pitfalls of the therapy are reviewed. The impact of hypertonic citrate solution during regional citrate anticoagulation is specifically discussed. Maintaining plasma hypertonicity in the setting of increased ICP and acute kidney injury could prevent the worsening of ICP during renal replacement therapy by minimizing the osmotic gradient across the blood-brain barrier and maximizing cardiovascular stability.

Impact of Dysnatremia and Dyskalemia on Prognosis in Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study

Background

Electrolyte disturbance is one of the complications of subarachnoid hemorrhage (SAH) and its prognostic value is not fully understood. The focus of this study is to evaluate the impact of dysnatremia and dyskalemia on functional outcomes in patients with aneurysmal SAH.

Materials and methods

Patients with spontaneous aneurysmal SAH who were admitted to our intensive care unit (ICU) between 1st January 2011 and 31st December 2016 were included. Demographic data, biochemical parameters from days 1 to day 11 of ICU admission, disease severity, and clinical outcome were recorded. The prognosis was estimated using the Glasgow outcome scale (GOS) at 3 months after the initial insult.

Results

A total of 244 patients were included in this study. There were 139 patients (57.0%) with hyponatremia (Na < 135 mmol/L) while 82 patients (33.6%) had hypernatremia (Na >146 mmol/L). Hyponatremia, hypernatremia, and sodium fluctuation >12 mmol/L were more commonly found in those patients with poor outcome. However, both hypokalemia and hyperkalemia were not shown to have a significant effect on the patient's prognosis. Logistic regression analysis identified the following independent predictors of poor outcome (GOS 1–3 at 3 months): age >55 years old, acute physiology and chronic health evaluation IV (APACHE IV) score >50, World Federation of Neurosurgical Societies (WFNS) grade >3, Fisher grade >2, presence of intracranial hemorrhage (ICH)/intraventricular hemorrhage (IVH), use of mannitol, use of loop diuretic aneurysms, involving posterior circulation, and hypernatremia >146 mmol/L.

Conclusion

Hypernatremia, but not hyponatremia, in patients with aneurysmal SAH is associated with poor outcome. Both hypokalemia and hyperkalemia were not shown to have a significant effect on the patient's prognosis. Further studies are required to determine whether the treatment of dysnatremia can influence outcomes.

Clinical significance

Dysnatremia and dyskalemia are common in patients with aneurysmal SAH, but only hypernatremia is associated with poor outcome. Further studies are required to determine whether the treatment of dysnatremia can influence outcomes.

How to cite this article

Tam CWY, Shum HP, Yan WW. Impact of Dysnatremia and Dyskalemia on Prognosis in Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study. Indian J Crit Care Med 2019;23(12):562–567.

Low-chloride versus high-chloride hypertonic solution for the treatment of subarachnoid hemorrhage-related complications (The ACETatE trial): study protocol for a pilot randomized controlled trial

Background

Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening condition that results from a ruptured cerebral vessel. Cerebral edema and vasospasm are common complications and frequently require treatment with hypertonic solutions, in particular hypertonic sodium chloride (NaCl). We have previously shown that hyperchloremia in patients with aSAH given hypertonic NaCl is associated with the development of acute kidney injury (AKI), which leads to higher morbidity and mortality. Our current trial aims to study the effect of two hypertonic solutions with different chloride content on serum chloride concentrations in patients with aSAH who are at risk for AKI.

Methods

A low ChloridE hyperTonic solution for brain Edema (ACETatE) is a single center, double-blinded, double-dummy pilot trial comparing bolus doses of 23.4% NaCl and 16.4% NaCl/Na-Acetate for the treatment of cerebral edema in patients with aSAH. All patients will be enrolled within 36 h following admission. Randomization will occur once patients who receive hypertonic treatment for cerebral edema develop hyperchloremia (serum Cl⁻ concentration ≥ 109 mmol/L). Subsequent treatment will consist of either NaCl 23.4% or NaCl/Na-Acetate 16.4%. The primary outcome of this study will be the change in serum Cl⁻ concentrations during treatment. Secondary outcomes will include incidence of AKI, mortality, changes in intracranial pressure, and extent of hypernatremia.

Discussion

In patients with aSAH, hyperchloremia is a known risk factor for subsequent development of AKI. The primary goal of this pilot study is to determine the effect of two hypertonic solutions with different Cl⁻ content on serum Cl⁻ concentrations in patients with aSAH who have already developed hyperchloremia. Data will be collected prospectively to determine the extent to which the choice of hypertonic saline solution affects subsequent serum Cl⁻ concentrations and the occurrence of AKI. This approach will allow us to obtain preliminary data to design a large randomized trial assessing the effects of chloride-sparing hypertonic solutions on development of AKI in patients with SAH. This pilot study is the first to prospectively evaluate the relationship between hypertonic solution chloride content and its effect on serum electrolytes and renal function in aSAH patients at risk of AKI due to hyperchloremia.

Trial registration

Clinicaltrials.gov, NCT03204955. Registered on 28 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3007-7) contains supplementary material, which is available to authorized users.

Does Fluid Type and Amount Affect Kidney Function in Critical Illness?

Acute kidney injury (AKI) is common, although commonly used clinical diagnostic markers are imperfect. Intravenous fluid administration remains a cornerstone of therapy worldwide, but there is minimal evidence of efficacy for the use of fluid bolus therapy outside of specific circumstances, and emerging evidence associates fluid accumulation with worse renal outcomes and even increased mortality among critically ill patients. Artificial colloid solutions have been associated with harm, and chloride-rich solutions may adversely affect renal function. Large trials to provide guidance regarding the optimal fluid choices to prevent or ameliorate AKI, and promote renal recovery, are urgently required.

Subarachnoid Hemorrhage: An Update

Subarachnoid hemorrhage (SAH) is a debilitating, although uncommon, type of stroke with high morbidity, mortality, and economic impact. Modern 30-day mortality is as high as 40%, and about 50% of survivors have permanent disability. Care at high-volume centers with dedicated neurointensive care units is recommended. Euvolemia, not hypervolemia, should be targeted, and the aneurysm should be secured early. Neither statin therapy nor magnesium infusions should be initiated for delayed cerebral ischemia. Cerebral vasospasm is just one component of delayed cerebral edema. Hyponatremia is common in subarachnoid hemorrhage and is associated with longer length of stay, but not increased mortality.

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.