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

Nutritional management of children with acute kidney injury-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

The nutritional management of children with acute kidney injury (AKI) is complex. The dynamic nature of AKI necessitates frequent nutritional assessments and adjustments in management. Dietitians providing medical nutrition therapies to this patient population must consider the interaction of medical treatments and AKI status to effectively support both the nutrition status of patients with AKI as well as limit adverse metabolic derangements associated with inappropriately prescribed nutrition support. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, has developed clinical practice recommendations (CPR) for the nutritional management of children with AKI. We address the need for intensive collaboration between dietitians and physicians so that nutritional management is optimized in line with AKI medical treatments. We focus on key challenges faced by dietitians regarding nutrition assessment. Furthermore, we address how nutrition support should be provided to children with AKI while taking into account the effect of various medical treatment modalities of AKI on nutritional needs. Given the poor quality of evidence available, a Delphi survey was conducted to seek consensus from international experts. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs, based on the clinical judgment of the treating physician and dietitian. Research recommendations are provided. CPRs will be regularly audited and updated by the PRNT.

Pediatric Hyperglycemic Hyperosmolar Syndrome: A Comprehensive Approach to Diagnosis, Management, and Complications Utilizing Novel Summarizing Acronyms

This paper focuses on hyperglycemic hyperosmolar syndrome (HHS), a unique hyperglycemic state requiring divergent diagnosis and treatment approaches from diabetic ketoacidosis (DKA) despite some shared characteristics. We introduce the mnemonic DI-FF-ER-EN-CE-S to encapsulate unique HHS management and complications. 'DI' emphasizes the need to delay and decrease initial insulin therapy until serum glucose decline is managed by fluid resuscitation alone. 'FF' stresses the importance of double fluid replacement compared to DKA due to severe dehydration and 'ER' electrolyte replacement due to profound losses and imbalances. 'EN' denotes the potential for encephalopathy and the requirement for a controlled serum osmolality reduction. 'CE' indicates cerebral edema, a rare complication in HHS. 'S' signifies systemic multiorgan failure. We categorize the associated risks into three mnemonic groups: the 3Rs (renal failure, respiratory distress, rhabdomyolysis), the 3Hs (heart failure, hypercoagulation, hyperthermia), and AP (arrhythmias, pancreatitis) to facilitate awareness and screening of HHS.

Peritoneal dialysis in the setting of acute brain injury: an underappreciated modality

INTRODUCTION

Dialysis is complicated in the setting of acute brain injury (ABI) due to several factors including acute solute shifts, acid base changes, need for anticoagulation, and changes in intracranial pressure. For these reasons, continuous renal replacement therapy (CRRT) is often the chosen modality for renal replacement needs in these patients. Peritoneal dialysis (PD) is less discussed but shares many of the benefits often attributed to CRRT. We describe, from both nephrology and neurosurgical perspectives, a case successfully managed with PD.

CASE

A 25-year-old male with history of end-stage kidney disease (ESKD) secondary to focal segmental glomerulosclerosis on continuous cycling PD for 5 years presented to the hospital with headache and altered mental status. Initial imaging revealed a large intraventricular hemorrhage extending to the fourth ventricle. He underwent an emergent right depressive hemicraniectomy and clot evacuation. Post-operative imaging revealed worsening cerebral edema, intraventricular hemorrhage, and hydrocephalus. The decision was made to continue PD, noting that it retains many of the benefits of CRRT (which it is in fact, a form of) which he tolerated well until the need for a percutaneous gastrostomy tube arose. He was transiently transitioned to hemodialysis but returned to PD once his gastrostomy healed. He continued PD for 1 year without complication and eventually received a kidney transplant.

DISCUSSION

In managing patients with ABI undergoing dialysis, a number of considerations must be undertaken including avoidance of hypotension to maintain cerebral perfusion pressure and minimize ischemia reperfusion injury, avoidance of anticoagulants that can precipitate or worsen bleeding, the potential for cerebral edema due to rapid solute clearance and osmotic dissipation of therapeutic hypernatremia, and the mitigation of intracellular acidosis from bicarbonate delivery. Although underutilized, PD may potentially serve as a viable option for dialysis in the setting of ABI as demonstrated by the case presented.

Management of regional citrate anticoagulation for continuous renal replacement therapy: guideline recommendations from Chinese emergency medical doctor consensus

Continuous renal replacement therapy (CRRT) is widely used for treating critically-ill patients in the emergency department in China. Anticoagulant therapy is needed to prevent clotting in the extracorporeal circulation during CRRT. Regional citrate anticoagulation (RCA) has been shown to potentially be safer and more effective and is now recommended as the preferred anticoagulant method for CRRT. However, there is still a lack of unified standards for RCA management in the world, and there are many problems in using this method in clinical practice. The Emergency Medical Doctor Branch of the Chinese Medical Doctor Association (CMDA) organized a panel of domestic emergency medicine experts and international experts of CRRT to discuss RCA-related issues, including the advantages and disadvantages of RCA in CRRT anticoagulation, the principle of RCA, parameter settings for RCA, monitoring of RCA (mainly metabolic acid-base disorders), and special issues during RCA. Based on the latest available research evidence as well as the paneled experts' clinical experience, considering the generalizability, suitability, and potential resource utilization, while also balancing clinical advantages and disadvantages, a total of 16 guideline recommendations were formed from the experts' consensus.

Dialysis Disequilibrium Syndrome and Intracranial Pressure Fluctuations in Neurosurgical Patients Undergoing Renal Replacement Therapy: Systematic Review and Pooled Analysis

BACKGROUND

Dialysis disequilibrium syndrome is a rare, well-known, potentially life-threatening complication of renal replacement therapy (RRT), often involving cerebral edema and increased intracranial pressure (ICP). However, the impact of RRT on ICP and rate of dialysis disequilibrium syndrome in neurosurgical patients have not been systematically assessed.

METHODS

In February 2022, a systematic review following PRISMA guidelines was conducted using various combinations of 9 keywords in the MEDLINE database. Eleven papers were selected. Individual patient data were extracted, pooled, and analyzed.

RESULTS

Fifty-eight patients, 44 men and 14 women with a mean age of 48 years (6-78 years), were analyzed. Neurosurgical conditions included the following: spontaneous intracranial hemorrhage (n = 27), traumatic brain injury (n = 16), ischemic stroke/anoxic brain injury (n = 6), intracranial tumor (n = 6), and others (n = 3). Neurosurgical interventions included the following: craniotomy/craniectomy (n = 23), external ventricular drain or ICP monitor placement (n = 16), and burr hole or twist drill craniostomy (n = 4). Intermittent dialysis was used in 33 patients, continuous RRT in 20, and a combination thereof in 4. During RRT, ICP increased in 35 patients (60.3%), remained unchanged in 20, and decreased in 3. Thirty-four patients (65.4%) died. Intermittent dialysis was associated with increased ICP (73% vs. 37.5%, P = 0.01) and mortality (75% vs. 39.1%, P = 0.01).

CONCLUSIONS

In neurosurgical patients, ICP increases during RRT are common, affecting up to 60%, and potentially life-threatening, with mortality rates as high as 65%. The use of a continuous rather than intermittent RRT technique may reduce the risk of this complication. Prospective studies are warranted.

Bedside ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure in nontraumatic neuro-critically ill patients

BACKGROUND

Delay in treatment of raised intracranial pressure (ICP) leads to poor clinical outcomes. Optic nerve sheath diameter (ONSD) by ultrasonography (US-ONSD) has shown good accuracy in traumatic brain injury and neurosurgical patients to diagnose raised ICP. However, there is a dearth of data in neuro-medical intensive care unit (ICU) where the spectrum of disease is different.

AIM

To validate the diagnostic accuracy of ONSD in non-traumatic neuro-critically ill patients.

METHODS

We prospectively enrolled 114 patients who had clinically suspected raised ICP due to non-traumatic causes admitted in neuro-medical ICU. US-ONSD was performed according to ALARA principles. A cut-off more than 5.7 mm was taken as significantly raised. Raised ONSD was corelated with raised ICP on radiological imaging. Clinical history, general and systemic examination findings, SOFA and APACHE 2 score and patient outcomes were recorded.

RESULTS

There was significant association between raised ONSD and raised ICP on imaging (P < 0.001). The sensitivity, specificity, positive and negative predictive value at this cut-off was 77.55%, 89.06%, 84.44% and 83.82% respectively. The positive and negative likelihood ratio was 7.09 and 0.25. The area under the receiver operating characteristic curves was 0.844. Using Youden’s index the best cut off value for ONSD was 5.75 mm. Raised ONSD was associated with lower age (P = 0.007), poorer Glasgow Coma Scale (P = 0.009) and greater need for surgical intervention (P = 0.006) whereas no statistically significant association was found between raised ONSD and SOFA score, APACHE II score or ICU mortality. Our limitations were that it was a single centre study and we did not perform serial measurements or ONSD pre- and post-treatment or procedures for raised ICP.

CONCLUSION

ONSD can be used as a screening a test to detect raised ICP in a medical ICU and as a trigger to initiate further management of raised ICP. ONSD can be beneficial in ruling out a diagnosis in a low-prevalence population and rule in a diagnosis in a high-prevalence population.

Management for Electrolytes Disturbances during Continuous Renal Replacement Therapy

Despite the lack of proven superiority in mortality compared to intermittent hemodialysis, continuous renal replacement therapy (CRRT) is the preferred renal replacement therapy modality for critically ill patients with acute kidney injury (AKI) due to better hemodynamic stability and steady correction of electrolytes disturbances and volume overload. Multiple and complex electrolyte disorders in patients with AKI can be managed effectively with CRRT because controlled and predictable correction is feasible. Thus, CRRT has an advantage with safety over conventional hemodialysis, especially in patients with both renal dysfunction and electrolyte disorder that require a sophisticated treatment with avoidance of rapid correction. On the contrary, CRRT can potentially lead to paradoxical disturbance of electrolytes such as hypokalemia or hypophosphatemia, especially in patients under high dose or prolonged duration of CRRT treatment. These electrolytes related complications can be prevented with close monitoring followed by the appropriate use of CRRT fluids. Although there is a lack of solid evidence and standardized guideline for CRRT prescriptions, optimal management of various electrolyte disturbances can be achieved with individualized and tailored dialysate and replacement fluid prescriptions. Several commercially available CRRT solutions with varying compositions provide flexibility to manage electrolyte disorders and maintain the stability of electrolyte. In this review, we discuss various prescription methods to manage common electrolyte imbalances as well as preventative strategies to maintain electrolyte homeostasis during CRRT providing detailed protocols used in our center. This review may contribute to future research that can lead to the development of clinical practice guidelines.

Continuous Renal Replacement Therapy in Acute Brain Injury

Acute brain injury is the sudden and reversible loss of brain self regulation capacity as a disruption of the blood-brain barrier that conditions metabolic and inflammatory disorders that can exacerbate acute kidney injury in a critical setting; specifically it has been described that the alterations of the internal environment that come from the severity of the acute kidney injury increases the risk of endocranial hypertension and cerebral edema; in this context, injuries should be identified and treated in a timely manner with a comprehensive approach. Continuous renal replacement therapy is an extracorporeal purification technique that has been gaining ground in the management of acute kidney injury in critically ill patients. Within its modalities, continuous venous venous hemofiltration is described as the therapy of choice in patients with acute brain injury due to its advantages in maintaining hemodynamic stability and reducing the risk of cerebral edema. Optimal control of variables such as timing to start renal replacement therapy, the prescribed dose, the composition of the replacement fluid and the anticoagulation of the extracorporeal circuit will have a significant impact on the evolution of the neurocritical patient with acute kidney injury. There are limited studies evaluating the role of hemofiltration in this context.

Dysnatremias in Chronic Kidney Disease: Pathophysiology, Manifestations, and Treatment

The decreased ability of the kidney to regulate water and monovalent cation excretion predisposes patients with chronic kidney disease (CKD) to dysnatremias. In this report, we describe the clinical associations and methods of management of dysnatremias in this patient population by reviewing publications on hyponatremia and hypernatremia in patients with CKD not on dialysis, and those on maintenance hemodialysis or peritoneal dialysis. The prevalence of both hyponatremia and hypernatremia has been reported to be higher in patients with CKD than in the general population. Certain features of the studies analyzed, such as variation in the cut-off values of serum sodium concentration ([Na]) that define hyponatremia or hypernatremia, create comparison difficulties. Dysnatremias in patients with CKD are associated with adverse clinical conditions and mortality. Currently, investigation and treatment of dysnatremias in patients with CKD should follow clinical judgment and the guidelines for the general population. Whether azotemia allows different rates of correction of [Na] in patients with hyponatremic CKD and the methodology and outcomes of treatment of dysnatremias by renal replacement methods require further investigation. In conclusion, dysnatremias occur frequently and are associated with various comorbidities and mortality in patients with CKD. Knowledge gaps in their treatment and prevention call for further studies.

Prescribing Continuous Kidney Replacement Therapy in Acute Kidney Injury: A Narrative Review

Severe acute kidney injury is a common complication in critically ill patients, often necessitating support with a modality of kidney replacement therapy. Continuous kidney replacement therapies (CKRTs) have become a mainstay in the management of patients with acute kidney injury in the intensive care unit. Understanding the fundamentals of CKRT is necessary to safely and effectively prescribe treatment. In this narrative review, we summarize critical aspects of CKRT management, including selection of the mode of therapy; choice of hemofilter/hemodialyzer used; determination of the blood flow rate, composition and flow rates of dialysate and/or replacement fluids, and the ultrafiltration rate; and use and methods of anticoagulation. Requirements for vascular access and appropriate monitoring and dose adjustment of medications and a plan for monitoring the delivery of therapy and ensuring appropriate nutritional management are also discussed.

Excessive elevation of serum phosphate during tumor lysis syndrome: Lessons from a particularly challenging case

Burkitt’s lymphoma is a common cause of tumor lysis syndrome (TLS) and, in the era of aggressive utilization of prophylactic allopurinol and recombinant uricase enzyme, nephrologists are increasingly witnessing monovalent or divalent cation abnormalities without marked uric acid elevation. An 18-year-old male received his 1^st cycle of intensive chemotherapy for Burkitt’s lymphoma and developed TLS as defined by the Cairo Bishop criteria. Lactate dehydrogenase peaked at 9,105 U/L (range: 130 – 250) and was accompanied by acute kidney injury, including serum creatinine 2.2 mg/dL on the 4^th day with oliguria, hyperkalemia, extreme hyperphosphatemia (21.4 mg/dL), hypermagnesemia, and hypocalcemia. Renal replacement therapy decision was made based on life-threatening electrolyte disturbances. The competing necessity to effectively control hyperphosphatemia and avoid the complication of dialysis disequilibrium syndrome prompted us to perform an initial intermittent hemodialysis with simultaneous intravenous mannitol administration, followed by continuous hemodialysis to manage the continued production of phosphorus from cell lysis. Osmotic stability during the therapy session was affirmatively demonstrated (322, 319 mOsm/kg, respectively). The patient showed excellent tolerance for these therapies and eventually recovered renal function as demonstrated during follow-up visits.

Effects of Hemodialysis on Prognosis in Individuals with Comorbid ERSD and ICH: A Retrospective Single-Center Study

OBJECTIVES

End-stage renal disease (ESRD) is one of the most critical risk factors of intracerebral hemorrhage (ICH). We aimed to investigate the effects of maintenance hemodialysis on hematoma volume, edema volume, and prognosis in patients with comorbid ESRD and ICH.

MATERIALS AND METHODS

Patients with comorbid ESRD and ICH were divided into two groups based on whether receiving maintenance hemodialysis. Hematoma and perihemorrhagic edema (PHE) volumes and relative edema ratio after admission were assessed on head computed tomography scans.

RESULTS

During the initial diagnosis, the dialysis group had lower PHE volume (16.41 vs 35.90 mL, P = 0.010), total volume of hematoma and edema (31.58 vs 54.58 mL, P = 0.013), and relative edema ratio (0.57 vs 0.92, P = 0.033) than the non-dialysis group. In addition, the peak PHE volume (36.68 vs 84.30 mL, P < 0.001), peak total volume of hematoma and edema (53.45 vs 127.69 mL, P = 0.011), and peak relative edema ratio (1.12 vs 1.92, P = 0.001) within one week after onset were lower in the dialysis group than in the non-dialysis group. The dialysis group had a higher in-hospital mortality rate than the non-dialysis group (40% vs 10%, P = 0.007). At 1-year follow-up, the two groups had similar 1-year-mortality rates and modified Rankin Scale.

CONCLUSIONS

Hemodialysis can prevent the enlargement of edema and reduce PHE volume shortly after onset. Although dialyzed patients had a higher in-hospital mortality rate, hemodialysis did not affect 1-year survival rate and functional neurologic scales.

Achieving Osmotic Stability in the Context of Critical Illness and Acute Kidney Injury During Continuous Renal Replacement Therapy

The concept of osmotic stability during renal replacement therapy has received limited attention thus far. We report an illustrative case of a previously healthy 22 year old male presenting after prolonged ventricular fibrillation with 75 minutes of resuscitative efforts before regaining spontaneous perfusing rhythm. Central nervous system protecting hypothermia protocol and veno-arterious (VA) extracorporeal membrane oxygenator (ECMO) therapy were initiated at hospital admission due to refractory hypoxemia. Cardiovascular imaging procedures described global hypokinesis. Due to the combination of anuria, mixed acidosis and hemodynamic instability, we started continuous renal replacement therapy (CRRT) in continuous veno-venous hemodiafiltration functionality with added hypertonic saline solution (HTS) protocol, calculated to stabilize his serum sodium between 148 and 150 mEq/L. Serum osmolality also ranged between 321 and 317 mOsm/kg thereafter. Course was complicated by an acute right leg ischemia distal to VA ECMO cannula placement, requiring salvage therapy with cryoamputation. Vasoactive medication requirement and hemodynamics improved after the addition of intravenous (IV) hydrocortisone. Brain magnetic resonance imaging (MRI) 22 days post-arrest showed signals of limited hypoxic injury. He left the hospital in stable condition with limited neurologic sequelae. Therefore, the use of HTS during CRRT is a viable way to address potential or manifest cerebral edema and reduce the degree of cerebral injury.

Sodium-Based Osmotherapy in Continuous Renal Replacement Therapy: a Mathematical Approach

Cerebral edema, in a variety of circumstances, may be accompanied by states of hyponatremia. The threat of brain injury from hypotonic stress-induced astrocyte demyelination is more common when vulnerable patients with hyponatremia who have end stage liver disease, traumatic brain injury, heart failure, or other conditions undergo overly rapid correction of hyponatremia. These scenarios, in the context of declining urinary output from CKD and/or AKI, may require controlled elevations of plasma tonicity vis-à-vis increases of the plasma sodium concentration. We offer a strategic solution to this problem via sodium-based osmotherapy applied through a conventional continuous RRT modality: predilution continuous venovenous hemofiltration.