Content – Evaluating Functional Status After Pediatric Continuous Kidney Replacement Therapy

Continuous kidney replacement therapy (CKRT) is used in the pediatric ICU (PICU) to support critically ill children who have acute kidney injury (AKI), fluid overload, and metabolic derangements. With ongoing measures to improve how CKRT is used in this patient population, mortality rates have decreased over the past 2 decades. “Although mortality rates after PICU stays for pediatric CKRT are decreasing, little is known about the impact of this treatment on acquired morbidities, functional status, and the quality of life on survivors after their PICU stay,” says Ayse Akcan-Arikan, MD.

For a study published in Pediatric Nephrology, Dr. Akcan-Arikan, Dr. Mallory B. Smith, and colleagues described risk factors associated for new morbidity, moderate to severe disability, and new technology dependence among pediatric survivors of CKRT. The retrospective study, conducted over 2 years, looked at 45 pediatric CKRT patients who survived to PICU discharge. The Functional Status Scale (FSS)—a validated tool that assesses mental status, sensory, communication, motor function, feeding, and respiratory domains—was used to determine functional outcome on ICU discharge.

A Significant Impact on Function

Results from the study showed that FSS scores were higher at PICU and hospital discharge compared to baseline and 69% of CKRT survivors had worse FSS scores at PICU discharge. “While FSS scores improved modestly at hospital discharge, function still never returned back to what it was at baseline,” says Dr. Akcan-Arikan. “We were also surprised to find that 51% of these patients had a new morbidity at PICU discharge. Most of these morbidities—which included needing a new tracheostomy, developing ventilator dependency, and becoming dialysis dependent—were moderate to severe.” In addition, more than half of all patients in the study required outpatient rehabilitation.

After controlling for severity of illness, cumulative number of days on sedation was identified as a critical factor associated with worse FSS scores at PICU discharge (Table). Conversely, genetic comorbidities and having surgery in the operating room were linked to lower odds of a new morbidity. “In adjusted analyses, the duration of sedation was associated with a new morbidity,” says Dr. Akcan-Arikan. Neurologic comorbidities, percent of fluid overload at CKRT initiation, and non-renal comorbidities were associated with moderate to severe disability at PICU discharge. Non-pulmonary comorbidities, longer sedation, and higher organ dysfunction scores on ICU admission were linked to higher FSS scores at hospital discharge.

Sobering Statistics Illustrate Vulnerability

“Our data are sobering in that we now have a better understanding of the vulnerability of these patients,” says Dr. Akcan-Arikan. “While the duration of CKRT was not necessarily a primary risk factor for worse functional outcome, it appears that sedation exposure and the duration of sedation are important risk factors to consider. Unfortunately, it’s challenging to think about the impact of medication accumulation and prolonged drug exposure when we’re managing this patient population.”

According to Dr. Akcan-Arikan, efforts are needed to develop interventional approaches to post-PICU follow-up. “CKRT survivors require close follow-up and monitoring in developmental clinics, similar to what is done for survivors of neonatal ICU stays and PICU survivors with congenital heart disease or traumatic brain injuries,” she says. “As we gain more information on the impact of PICU stays on pediatric CKRT survivors, it is becoming increasingly necessary to create developmental follow-up clinics that can better equipped to manage these patients.”

Developing Interventions to Optimize Follow-Up

Given the study findings, more research is needed to explore modifiable risk factors for CKRT survivors in inpatient and outpatient settings during follow-up so that resources can be appropriately allocated to improve outcomes. “If our findings are confirmed in multicenter studies, the risk factors for adverse outcomes identified in our study may help with the development of interventional targets during hospitalizations to optimize patient follow-up” Dr. Akcan-Arikan says. “It will also be important to monitor these trends in pediatric CKRT survivors during the COVID-19 pandemic. In the meantime, clinicians should be mindful of risk factors like sedation dosing and exposure to potentially help minimize risks for creating additional adverse consequences.”