Management of toxic ingestions with the use of renal replacement therapy

Peritoneal Dialysis in Critically Ill Patients: Time for a Critical Reevaluation?

Peritoneal dialysis (PD) as an AKI treatment in adults was widely accepted in critical care settings well into the 1980s. The advent of extracorporeal continuous KRT led to widespread decline in the use of PD for AKI across high-income countries. The lack of familiarity and comfort with the use of PD in critical care settings has also led to lack of use even among those receiving maintenance PD. Many critical care units reflexively convert patients receiving maintenance PD to alternative dialysis therapies at admission. Renewed interest in the use of PD for AKI therapy has emerged due to its increasing use in low- and middle-income countries. In high-income countries, the coronavirus disease 2019 (COVID-19) pandemic, saw PD for AKI used early on, where many critical care units were in crisis and relied on PD use when resources for other AKI therapy modalities were limited. In this review, we highlight advantages and disadvantages of PD in critical care settings and indications and contraindications for its use. We provide an overview of literature to support both PD treatment during AKI and its continuation as a maintenance therapy during critical illness. For AKI therapy, we further discuss establishment of PD access, PD prescription management, and complication monitoring and treatment. Finally, we discuss expansion in the use of PD for AKI therapy extending beyond its role during times of resource constraints.

Pharmacokinetic Alterations Associated with Critical Illness

Haemodynamic, metabolic, and biochemical derangements in critically ill patients affect drug pharmacokinetics and pharmacodynamics making dose optimisation particularly challenging. Appropriate therapeutic dosing depends on the knowledge of the physiologic changes caused by the patient's comorbidities, underlying disease, resuscitation strategies, and polypharmacy. Critical illness will result in altered drug protein binding, ionisation, and volume of distribution; it will also decrease oral drug absorption, intestinal and hepatic metabolism, and renal clearance. In contrast, the resuscitation strategies and the use of vasoactive drugs may oppose these effects by leading to a hyperdynamic state that will increase blood flow towards the major organs including the brain, heart, kidneys, and liver, with the subsequent increase of drug hepatic metabolism and renal excretion. Metabolism is the main mechanism for drug clearance and is one of the main pharmacokinetic processes affected; it is influenced by patient-specific factors, such as comorbidities and genetics; therapeutic-specific factors, including drug characteristics and interactions; and disease-specific factors, like organ dysfunction. Moreover, organ support such as mechanical ventilation, renal replacement therapy, and extracorporeal membrane oxygenation may contribute to both inter- and intra-patient variability of drug pharmacokinetics. The combination of these competing factors makes it difficult to predict drug response in critically ill patients. Pharmacotherapy targeted to therapeutic goals and therapeutic drug monitoring is currently the best option for the safe care of the critically ill. The aim of this paper is to review the alterations in drug pharmacokinetics associated with critical illness and to summarise the available evidence.

Lactic acidosis and multisystem organ failure following ibuprofen overdose requiring haemodialysis

A 17-year-old man was admitted to the paediatric intensive care unit 2 hours following an intentional ingestion of unknown substances. In the first 23 hours of hospitalisation, lactate levels remained elevated at 2-4 mmol/L, during the 24th hour, he developed lactic acidosis with lactate levels increasing from 4 to 16 mmol/L. His neurological status declined, requiring orotracheal intubation. Central and arterial access were obtained, and vasoactive infusions were initiated for haemodynamic support. Due to increasing lactate levels (maximum level >24 mmol/L) and haemodynamic instability, a dialysis line was inserted, and continuous renal replacement therapy (CRRT) was initiated. The lactic acidosis resolved over 10 hours. Serum ibuprofen level subsequently resulted at 841 µg/mL (reference range 10-50). Few reported cases discuss the sequela of large quantity ibuprofen ingestion leading to severe lactic acidosis and multiorgan system failure. Early intervention with CRRT may reverse acidosis, stabilise haemodynamics and halt secondary organ failure.

Basics of continuous renal replacement therapy in pediatrics

In the last three decades, significant advances have been made in the care of children requiring renal replacement therapy (RRT). The move from the use of only hemodialysis and peritoneal dialysis to continuous venovenous hemofiltration with or without dialysis (continuous renal replacement therapy, CRRT) has become a mainstay in many intensive care units. The move to CRRT is the result of greater clinical experience as well as advances in equipment, solutions, vascular access, and anticoagulation. CRRT is the mainstay of dialysis in pediatric intensive care unit (PICU) for critically ill children who often have hemodynamic compromise. The advantages of this modality include the ability to promote both solute and fluid clearance in a slow continuous manner. Though data exist suggesting that approximately 25% of children in any PICU may have some degree of renal insufficiency, the true need for RRT is approximately 4% of PICU admissions. This article will review the history as well as the progress being made in the provision of this care in children.

Sequential use of hemoperfusion and single-pass albumin dialysis can safely reverse methotrexate nephrotoxicity

BACKGROUND

High-dose methotrexate therapy (HDMTX) is a common form of chemotherapy used in children with high-grade malignancy such as osteosarcoma. Treatment with HDMTX requires careful monitoring of drug levels with folinic acid (leucovorin) rescue therapy. Toxicity from methotrexate is not uncommon and sometimes causes significant morbidity and mortality.

CASE-DIAGNOSIS/TREATMENT

We report an 11-year-old child whose 24-h post-HDMTX serum level was 651.8 μmol/L (recommended level <20 μmol/L), which was complicated by septic shock and progressive renal and liver failure. As carboxypeptidase (glucarpidase) was not available locally, she was treated with the sequential use of charcoal hemoperfusion (CHP) and single-pass albumin dialysis (SPAD). The patient recovered without complications. Both liver and renal function recovered with no significant late sequelae.

CONCLUSION

CHP and SPAD are effective extracorporeal methods of removing methotrexate. They provide alternative treatment options for critical care nephrologists in the management of methotrexate toxicity.

Available extracorporeal treatments for poisoning: overview and limitations

Poisoning is a significant public health problem. In severe cases, extracorporeal treatments (ECTRs) may be required to prevent or reverse major toxicity. Available ECTRs include intermittent hemodialysis, sustained low-efficiency dialysis, intermittent hemofiltration and hemodiafiltration, continuous renal replacement therapy, hemoperfusion, therapeutic plasma exchange, exchange transfusion, peritoneal dialysis, albumin dialysis, cerebrospinal fluid exchange, and extracorporeal life support. The aim of this article was to provide an overview of the technical aspects, as well as the potential indications and limitations of the different ECTRs used for poisoned patients.

Renal complications and therapy in the PICU: hypertension, CKD, AKI, and RRT

This article provides the bedside clinician an overview of the unique renal complications that are seen commonly in the pediatric intensive care unit. These sections are purposely succinct to give a quick guide to the clinician for the care of these children. We have identified four major areas that should result in discussion and cooperative care between intensive care physicians and nephrologists for the care of these children: (1) hypertension, (2) chronic kidney failure, (3) acute kidney injury, and (4) renal replacement therapy.

Pediatric renal replacement therapy in the intensive care unit

Renal replacement therapy (RRT) is used in a wide variety of pediatric populations. In this article, we will review the advantages and disadvantages of the different RRT modalities and the technical aspects of providing pediatric RRT. In addition, we will review the use of RRT with extracorporeal membrane oxygenation, the use of continuous RRT in the critically ill child with acute kidney injury and fluid overload, and the use of RRT for the removal of toxins and treatment of inborn errors of metabolism.