Practice Patterns and Outcomes of Hemodialysis in Infants Undergoing Congenital Heart Surgery in th

The Problem

Severe acute kidney injury requiring dialysis develops in 1% of infants after congenital heart surgery 0:07. When it does, the mortality burden is substantial: one-year survival drops to 46%, compared with 94% for infants who do not require dialysis 0:14 0:14. Most affected infants receive continuous renal replacement therapy rather than intermittent hemodialysis 0:23.

The Volume-Outcome Relationship

Institutional experience matters. Hospitals that use dialysis more frequently in this population demonstrated three times higher hospital survival and double the one-year survival rate 0:33 0:33. This volume-outcome relationship persists despite the rarity of the complication 0:39.

Implications for Referral and Transfer

The findings suggest that when severe acute kidney injury develops after infant cardiac surgery, outcomes may improve if the patient is managed at a center with greater dialysis experience in this population 0:44. For institutions that perform congenital heart surgery but rarely initiate dialysis in infants, these data support early discussion with higher-volume centers when renal replacement therapy becomes necessary.

The mechanism underlying the survival advantage at high-volume centers remains unclear from these data — it may reflect technical expertise in vascular access and circuit management in small infants, more aggressive initiation thresholds, better integration between cardiac intensive care and nephrology teams, or unmeasured case-mix differences. What is clear is that the survival gap is large enough to inform clinical decision-making about where these critically ill infants receive care.

The Problem

Severe acute kidney injury requiring dialysis develops in 1% of infants after congenital heart surgery 0:07. One-year survival for infants requiring hemodialysis is 46%, compared to 94% for those who do not 0:14 0:14. Most affected infants receive continuous renal replacement therapy rather than intermittent dialysis 0:23.

The Volume-Outcome Effect

Hospitals that use dialysis more frequently after infant cardiac surgery achieve three times higher hospital survival and double the one-year survival rate 0:33 0:33. This volume-outcome relationship persists despite the rarity of the complication 0:39.

Clinical Implication

For the cardiac intensivist or surgeon managing postoperative infants, this creates a referral decision point. When severe AKI develops requiring renal replacement therapy, outcomes may improve at centers with greater dialysis experience in this population 0:44. The magnitude of the survival difference—threefold at hospital discharge, twofold at one year—suggests that technical proficiency, protocol refinement, and multidisciplinary coordination around dialysis access, anticoagulation, and fluid management accumulate meaningfully with case volume.

What Remains Uncertain

The study does not establish a volume threshold that defines adequate experience, nor does it account for case-mix differences between high- and low-volume centers. Whether the survival advantage reflects dialysis technique specifically or broader institutional capability in managing complex postoperative infants is unclear. The choice between CRRT and intermittent dialysis may also be confounded by center practice patterns rather than patient-specific factors.

The Problem

Severe acute kidney injury requiring dialysis develops in 1% of infants after congenital heart surgery 0:07. When it occurs, the mortality burden is substantial: one-year survival falls to 46%, compared with 94% for infants who do not require dialysis 0:14 0:14.

Current Practice

Most infants who require renal support receive continuous renal replacement therapy rather than intermittent hemodialysis 0:23. This reflects the hemodynamic instability typical of post-operative cardiac infants, though the study does not detail the clinical reasoning behind modality selection.

The Volume-Outcome Relationship

Institutional experience with dialysis appears to matter significantly [q2]. Hospitals that use dialysis more frequently after infant cardiac surgery demonstrated three times higher hospital survival and double the one-year survival rate compared with lower-volume centers 0:33 0:33. The mechanism is not specified — whether it reflects technical expertise, nursing familiarity, earlier recognition of dialysis candidacy, or some combination — but the magnitude of effect is striking.

Clinical Implications

Dialysis after infant heart surgery remains rare 0:39, which creates a paradox: the condition is uncommon enough that most centers have limited experience, yet outcomes appear substantially better where that experience exists. The data suggest that when severe acute kidney injury develops in a post-operative cardiac infant, outcomes may improve if the child is treated at a center with more dialysis experience 0:44. This raises questions about regionalization, transfer thresholds, and whether certain high-risk operations should be concentrated at centers equipped to manage this complication.

What remains unclear is the threshold that defines "high volume" and whether the relationship is linear or has an inflection point. The study also does not address whether the survival difference persists after risk adjustment for surgical complexity.